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https://dev.heuristiclab.com/trac.fcgi/wiki/WikiStart?version=87 | Version 87 (modified by abeham, 5 years ago) (diff)
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HeuristicLab is a framework for heuristic and evolutionary algorithms that is developed by members of the Heuristic and Evolutionary Algorithms Laboratory (HEAL) since 2002. The developers team of HeuristicLab uses this page to coordinate efforts to improve and extend HeuristicLab.
• Graphical User Interface
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• Simulation-based Optimization
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Publications
View Publications | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8036006689071655, "perplexity": 11619.6054370958}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195529007.88/warc/CC-MAIN-20190723064353-20190723090353-00190.warc.gz"} |
http://www.tutornext.com/math/types-of-regular-polygon.html | Sales Toll Free No: 1-855-666-7440
# Types of Regular Polygon
A quadrilateral is special types of polygon which has four sides. Any quadrilateral has four sides ,four angles, four vertex. There are five types of regular polygon (quadrilateral). Trapezium, Parallelogram, Rhombus. Rectangle and Square. There is also a quadrilateral which has no regular shape that is known as only quadrilateral.
## Trapezium
TRAPEZIUM: A quadrilateral which has exactly one pair of opposite sides as parallel is called trapezium. The following figures are of trapezium because in each figure one pair of opposite sides are parallel.
## Parallelogram
PARALLOGRAM: A quadrilateral is a parallelogram if opposite sides are parallel. The following figure shows a parallelogram.
In the above figure, quadrilateral is a parallelogram because AB?DC, AD?BC.
PROPERTIES OF A PARALELLOGRAM:
• Opposite sides are equal. So AB =DC, AD = BC.
• Opposite angles are equal. So LA=LC and LB=LD
• Sum of adjacent angles are equal to 180o.
• Diagonals are not equal in length. So AC $\ne$ BD.
## Rhombus
RHOMBUS: A parallelogram having all sides are equal, called a rhombus. The following figure shows a rhombus.we use this in finidng area of
In the above figure, quadrilateral is a rhombus because AB = BC =CD = DA and. AB?DC, AD?BC.
Properties of A Rhombus:
• All sides are equal. So. AB = BC =CD = DA
• Opposite angles are equal. So LA=LC and LB=LD
• Sum of adjacent angles are equal to 180o.
• Diagonals are not equal in length. So AC $\ne$ BD.. But intersect each other at right angle. So LAOD = Right Angle.
## Rectangle
RECTANGLE: A parallelogram having one angle equal to 90o, is called a rectangle.The following figure shows a rectangle.
In the above figure, quadrilateral is a rectangle because, AB =DC, AD = BC and. AB?DC, AD?BC.
PROPERTIES OF A RECTANGLE:
• Opposite sides are equal. So. AB =DC, AD = BC.
• All angles are equal and of 90o.
• Sum of adjacent angles are equal to 180o.
• Diagonals are equal in length. So AC = BD.
## Square
SQUARE: A rhombus having one angle equal to 90o, called a square. The following figure shows a square.
In the above figure, quadrilateral is a square because AB = BC =CD = DA and. LAOD = 90 degree and LADC = 90 degree.
PROPERTIES OF A SQUARE:
• All sides are equal. So. AB = BC =CD = DA
• All angles are equal.
• Sum of adjacent angles are equal to 180o.
• Diagonals are equal in length. So AC= BD. and intersect each other at right angle. So LAOD = 90 degree
## Kite
KITE: A quadrilateral is a kite if its one both pairs of adjacent sides are unequal. The following figure shows a kite.
In the above figure, quadrilateral is a kite because AB $\ne$ BC and AD $\ne$ DC.
PROPERTIES OF A KITE:
• Two pair of adjacent sides are equal. So AD =AB, DC = BC. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6335219144821167, "perplexity": 2017.283509640284}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-17/segments/1524125945637.51/warc/CC-MAIN-20180422174026-20180422194026-00294.warc.gz"} |
https://www.intechopen.com/chapters/60249 | Open access peer-reviewed chapter
# Ultrafast Intramolecular Proton Transfer Reaction of 1,2- Dihydroxyanthraquinone in the Excited State
By Sebok Lee, Myungsam Jen, Kooknam Jeon, Jaebeom Lee, Joonwoo Kim and Yoonsoo Pang
Submitted: December 6th 2017Reviewed: February 21st 2018Published: March 27th 2018
DOI: 10.5772/intechopen.75783
## Abstract
1,2-Dihydroxyanthraquinone (alizarin) shows an ultrafast intramolecular proton transfer in the excited states between the adjacent hydroxyl and carbonyl groups. Due to the ground and electronic structure of locally excited and proton-transferred tautomers, alizarin shows dual emission bands with strong Stokes shifts. The energy barriers between the locally excited (LE) and proton-transferred (PT) tautomers in the excited state are strongly dependent on the solvent polarity and thus alizarin shows complicated photophysical properties including solvent and excitation dependences. The excited-state intramolecular proton transfer (ESIPT) of alizarin was monitored in time-resolved stimulated Raman spectroscopic investigation, where the instantaneous structural changes of anthraquinone backbone in 70~80 fs were captured. Two major vibrational modes of alizarin, ν(C=C) and ν(C=O) represent the proton transfer reaction in the excited state, which then leads to the vibrational relaxation of the product and the restructuring of solvent molecules. Ultrafast changes in solvent vibrational modes of dimethyl sulfoxide (DMSO) were also investigated for the solvation dynamics including hydrogen bond breaking and reformation.
### Keywords
• excited-state intramolecular proton transfer
• tautomerization
• femtosecond stimulated Raman
• transient absorption
## 1. Introduction
Proton transfer occurring either intramolecularly or intermolecularly is one of the fundamental chemical reactions and has been of great interest in chemistry, biology, and related disciplines [1, 2, 3, 4, 5]. Molecules with the excited-state intramolecular proton transfer (ESIPT) often show large Stokes shifts, which is beneficial in many photonic applications due to small self-absorption [6, 7]. The ESIPT reactions have been extensively studied by time-resolved spectroscopic methods, where the ultrafast laser pulses initiate the chemical reaction in the excited state [6, 7, 8, 9, 10]. Femtosecond transient absorption technique was used as the time-resolved electronic probe in monitoring ultrafast proton transfer reactions in the time scales of ~30 fs [8, 10]. Recently, a much faster ESIPT of ~13 fs in 10-hydroxybenzo[h]quinolone has been reported by a fluorescence upconversion technique [9].
1,2-Dihydroxyanthraquinone (alizarin) is one of natural red pigments which forms an intramolecular hydrogen bond between a carbonyl and a hydroxyl group in the ground and excited states [11, 12, 13, 14, 15, 16, 17, 18]. Upon photoexcitation, a proton transfer from the hydroxyl to the carbonyl group occurs and the dual emission bands of the locally excited (LE) and proton-transferred (PT) tautomers have been reported [11, 12, 13, 14]. The scheme of electronic structure of alizarin in LE and PT tautomers is shown in Figure 1. Since the barrier between LE and PT tautomers of alizarin in the excited state is tunable by changing solvent polarity [19, 20], the proton transfer reaction dynamics between the LE and PT tautomers might also be controlled by this factor. The emission band of the PT tautomer dominates in nonpolar aprotic solvents while the dual emission bands both from the LE and PT tautomers appear in polar aprotic solvents with the inhibition of the ESIPT reaction [21, 22]. According to the density functional theory (DFT)/time-dependent DFT (TDDFT) simulation results, the LE tautomer of alizarin is more stable (4.7–4.8 kcal/mol) than the PT tautomer in ground state, while the LE tautomer becomes less stable in the excited state with tunable energy barriers between the LE and PT [23]. For example, the energy barrier from the LE to PT tautomer in the exited state was estimated as 1.30 kcal/mol in benzene (nonpolar aprotic) and 3.19 kcal/mol in ethanol (polar aprotic).
The excited state lifetime of the alizarin PT tautomer was observed as 60–80 ps in several time-resolved spectroscopic investigations on alizarin, but the exact proton transfer dynamics of alizarin was not clearly obtained due to strong excited state absorption and emission signals, and complicated excited state dynamics including vibrational relaxations, solvations, etc., [20, 24, 25, 26]. However, the ultrafast ESIPT reactions (45–120 fs) of several anthraquinone derivatives including 1-hydroxyanthraquinone and 1-chloroacetylaminoanthraquinone have been measured by time-resolved fluorescent measurements [11, 15, 27, 28].
Femtosecond stimulated Raman spectroscopy (FSRS) with both high temporal (<50 fs) and spectral (<10 cm−1) resolutions was introduced recently for the study of excited state dynamics and reaction mechanisms [29, 30] and has been widely used to study the photo-induced population and structural dynamics in many chemical and biological systems [31, 32, 33, 34].
In this chapter, the ESIPT reaction and excited state dynamics of alizarin will be overviewed by using experimental results of steady-state absorption and emission, femtosecond transient absorption, and femtosecond stimulated Raman measurement. The excited state dynamics of alizarin was examined by changing the solvent polarity and the evidence for the ultrafast proton transfer reaction and subsequent structural changes in the product state were inspected by the time-dependent skeletal vibrational modes of alizarin.
## 2. Experimental details
### 2.1. Chemical preparation
Alizarin (Sigma-Aldrich, St. Louis, MO), dimethyl sulfoxide (DMSO, Daejung Chemicals and Metals, Siheung, Korea), ethanol (Duksan Pure Chemicals, Ansan, Korea), and other chemicals were used as received. Alizarin hardly dissolves in water but dissolves in most organic solvents, so alizarin solutions (33–50 μM) were prepared in ethanol and DMSO for the steady-state absorption and emission, and transient absorption measurements. A 2 mm cell with a stirring magnet was used for transient absorption measurements to avoid photo-damage from the laser pulses. The DMSO solutions of alizarin up to 20-mM concentrations in a 0.5 mm flow cell recirculated by a peristaltic pump were used for stimulated Raman measurements.
### 2.2. Steady-state absorption and emission measurements
The absorption spectra were recorded by a UV/Vis spectrometer (S-3100, Scinco, Seoul, Korea) and the emission spectra were obtained by a time-resolved fluorescence setup based on a time-correlated single photon-counting module (Picoharp 300, PicoQuant, Berlin, Germany), a picosecond diode laser (λex = 405 nm; P-C-405, PicoQuant), a monochromator (Cornerstone 260, Newport Corp., Irvine, CA), and a photomultiplier tube detector (PMA 192, PicoQuant).
### 2.3. Transient absorption spectroscopy
A femtosecond transient absorption setup based on a Ti:sapphire regenerative amplifier (LIBRA-USP-HE, Coherent Inc., Santa Clara, CA) was used for transient absorption measurements [35, 36]. The pump pulses at 403 nm were generated by sum-harmonic generation (SHG) in a BBO crystal (θ = 29.2°, Eksma Optics, Vilnius, Lithuania) and compressed in a prism-pair compressor. The whitelight supercontinuum probe pulses (450–1000 nm) generated in a sapphire window were tightly focused to the sample with the pump and detected with a fiber-based spectrometer (QE65Pro, Ocean Optics, Largo, FL). Transient absorption spectra and kinetics were analyzed in a global fit analysis by using a software package Glotaran [37].
### 2.4. Femtosecond stimulated Raman spectroscopy
A femtosecond stimulated Raman setup based on the Ti:sapphire regenerative amplifier (LIBRA-USP-HE) was used for time-resolved Raman measurements. A narrowband picosecond pulses (802 nm, 0.6 nm, 1.2 ps) generated by a home-built grating filter (1200 gr/mm) was used for the Raman pump, and a broadband (850–1000 nm) whitelight continuum generated in a YAG window (Newlight Photonics, Toronto, ON) was used for the Raman probe. The Raman probe filtered with long pass filters (FEL0850, Thorlabs Inc., Newton, NJ; 830 DCLP, Omega Optical Inc., Brattleboro, VT) was combined at the sample with the Raman pump and the actinic pump at 403 nm generated from SHG. The Raman pump was modulated at 500 Hz by an optical chopper (MC2000, Thorlabs Inc.) and the Raman probe was recorded at 1 kHz shot-to-shot level by a spectrograph (Triax 320, Horiba Jobin Yvon GmbH, Bensheim, Germany) and a CCD detector (PIXIS 100, Princeton Instruments, Trento, NJ). The optical time delay between the actinic pump and the Raman pump/probe pair was controlled by a motorized stage (MFN25PP, Newport Inc.) and a controller (ESP300, Newport Inc.). The Raman pump of 350 nJ pulse energy and the actinic pump of 750 nJ pulse energy were used in a typical FSRS measurement.
### 2.5. Computational details
DFT simulations for the Raman vibrational modes of alizarin were conducted by the Gaussian 09 software package (Gaussian Inc., Wallingford, CT), and the B3LYP/6-31G(d,p) level of theory with the optimized geometries from previous TDDFT results was used [23, 38]. The scaling factors for the vibrational frequencies obtained in previous reports were used to visualize the Raman spectra of alizarin both in ground and excited electronic states with arbitrary bandwidths of 10–15 cm−1 [39].
## 3. Steady-state absorption and emission spectra of alizarin
In the ground state, the LE tautomer exists lower than the PT tautomer in energy and the energy barrier between two tautomers is too high for the proton transfer in the ground state to be observed [19]. On the other hand, the LE tautomer in the excited state which can be approached by photoexcitation exists higher in energy than the PT tautomer, and the tautomerization to the PT tautomer can occur depending on the barrier height separating two tautomers [11, 12, 13, 14, 16, 27, 40].
The absorption and emission spectra of alizarin in n-heptane, ethanol, and DMSO solution are shown in Figure 2(a). The absorption spectrum of alizarin in n-heptane appears as several vibronic bands at ~405, 425, and 450 nm and the absorption bands of alizarin in both ethanol and DMSO are inhomogeneously broadened and red-shifted by 20–30 nm from the bands in n-heptane. The emission bands of alizarin in n-heptane centered at 610 and 660 nm show large Stokes’ shifts from the absorption band representing the intramolecular proton transfer in the excited state. The emission spectra of alizarin in ethanol and DMSO show increased emission in the range of 500–600 nm in addition to main emission bands at 620 and 670 nm, which is interpreted as the emission signal originating from the LE state in the excited state.
Figure 2(b) shows the dependence of the excitation wavelength in the emission spectra of alizarin in ethanol. Alizarin shows two emission bands in ethanol solution. One centered at 535 nm from the LE tautomer appears strongly with 485 nm excitation, while the other centered at 620 nm from the PT tautomer becomes the main band with 405-nm excitation. The excess energy in the 405-nm excitation may facilitate the ESIPT by overcoming the energy barrier of the LE-PT tautomerization. Concentration and wavelength dependences in the emission spectra of alizarin can be the evidence for the existence of the energy barrier between the LE and PT tautomers [19, 20, 41].
To further investigate the intramolecular proton transfer of alizarin and the solvent dependence, the steady-state absorption and emission spectra of alizarin in binary mixtures of ethanol and water were measured with 405-nm excitation as shown in Figure 3. The absorption spectra of alizarin show a slight increase in absorbance with the addition of water to ethanol up to 50% without any spectral change. However, the emission spectra of alizarin show a strong solvent dependence. The PT emission bands at 615 and 670 nm decrease as the fraction of water increases up to 50% while the LE emission band at 530 nm increases. The isosbestic point between the LE and PT emission bands is clearly observed at 560 nm, which clearly supports the transition between the LE and PT tautomers. In addition, a decrease of overall quantum yield of alizarin with the addition of water may represent a nonradiative rate constant of the LE tautomer is much smaller than that of the PT tautomer. Recently, the effect of water on the ESIPT reaction of alizarin was further investigated by the simulations based on the time-dependent density functional theory [42]. It has been noted that the strong intramolecular hydrogen bonding of alizarin between the carbonyl and hydroxyl group may facilitate the ESIPT reaction in the excited state. Furthermore, the inhibition of the ESIPT process by water molecules by forming hydrogen bonds with the carbonyl or hydroxyl groups of alizarin was proposed, which weakens the intramolecular hydrogen bonding associated with the ESIPT process and thus increases the energy barrier between the LE and PT tautomer [42].
We have used time-resolved electronic (femtosecond transient absorption) and vibrational spectroscopy (FSRS) to further study the detailed kinetics and mechanism of the ESIPT reaction of alizarin in the excited state.
## 4. Excited state intramolecular proton transfer of alizarin
### 4.1. Femtosecond transient absorption results
Transient absorption results of alizarin in ethanol and in a binary mixture of ethanol:water = 1:1 with 403-nm excitation are shown in Figure 4. Within 10 ps time delay, the excited state absorption (ESA) band centered at 510 nm and the stimulated emission (SE) band in the 570–750 nm range are observed in both ethanol and ethanol-water mixture. A broad and weak ESA band in the 500–550 nm range is left after 1 ns time delay for the ethanol-water mixture, while all the excited state population of alizarin in ethanol solution decays to the ground state by the same time. The global fit results for alizarin in ethanol are summarized by two kinetic components of 8.3 and 87 ps whose evolution associated difference spectra (EADS) are shown in Figure 4(a). The 8.3 ps component with slightly broader absorption band (450–580 nm) but without emission signal represents the vibrationally hot PT tautomer, and the 87 ps component with both absorption and emission (580–750 nm) signals represents the relaxed PT tautomer in the excited state, which is consistent with previous results [20, 24, 25, 26].
The excited state dynamics of alizarin in ethanol-water mixture is somewhat complex. Instead of performing the global fit analysis of the whole transient absorption data, we analyzed the absorption (<580 nm) and emission (>580 nm) part of the data separately in the global fit analysis. We found three kinetic components of 7.6, 31.8, and 890 ps from the absorption part and two components of 15.7 and 540 ps from the emission part of the data. The kinetic components of 7.6 and 31.8 ps in the absorption part are tentatively assigned as the vibrationally hot and relaxed PT tautomers of alizarin, respectively, by inferring from the results of ethanol solution. However, the 7.6 ps component may include the decay of the LE state, as the blocking of the proton transfer reaction was observed with the addition of water from results of the steady-state emission spectra. The 15.7 ps lifetime of the first emission component of the data is much shorter than the lifetime of 31.8 ps component in the absorption part, thus this component may also represent the emission signal of both the LE and PT tautomer which cannot be separated in all the analysis we have done. In addition to the fast kinetic components for the LE and PT tautomers, a long-lived component (540 or 890 ps) appeared as a very broad absorption band in 500–600 nm.
It is noted that the shortened lifetime of the PT tautomer (87 → 31.8 ps) with the addition of water to ethanol observed in transient absorption measurements is consistent to the reduced quantum yield and the increased nonradiative rate constant of alizarin observed in the steady-state emission measurements. As suggested by the recent theoretical study [42], water molecules may form hydrogen bonds with the carbonyl and hydroxyl groups of alizarin and impede the intramolecular proton transfer reaction of alizarin. Thus the long decay component in the transient absorption of alizarin in ethanol-water mixture may be considered as the “trapped” state of alizarin with water molecules. Further details on the solute-solvent interaction and resulting ESIPT kinetics can be investigated by FSRS, where time-resolved structural changes of solute and solvent molecules can be monitored.
It has been proposed that faster components of 300–400 fs time constant generally observed from the transient absorption signals of alizarin in the wavelengths (570–585 nm) where the strong ESA and SE signals cancel out, may represent the kinetics for the vibrational relaxation in the LE tautomer and the ESIPT to the PT tautomer [41, 43]. We also observed these fast components universally in the transient absorption results of alizarin in ethanol, methanol, DMSO, and ethanol-water mixture (examples are shown in Figure 4(c) and (d)), but did not show any dependence on the solvent polarity. Since the ESA, SE, and the ground-state bleaching signals of two tautomers of alizarin in transient absorption measurements are overlapped in wavelength and time, it seems to be very difficult to separate the kinetic components of the vibrational relaxation of the LE and PT tautomers, the ESIPT, etc. We conclude that the transient absorption measurements may be inadequate for the correct analysis of the ESIPT process, a further investigation by FSRS was performed to obtain the population and structural dynamics of alizarin upon photoexcitation.
### 4.2. Femtosecond stimulated Raman results
#### 4.2.1. FSRS details
Alizarin is soluble in ethanol and DMSO but the Raman spectrum of ethanol overlaps that of alizarin in many spectral regions. Then small changes in the vibrational modes of alizarin might not be observed in ethanol solution due to strong Raman modes of ethanol. The Raman bands of DMSO, however, can be separable from the Raman modes of alizarin. Thus femtosecond stimulated Raman measurements of alizarin were done with DMSO solution. From the analysis of transient absorption result of alizarin in DMSO solution, two kinetic components were obtained [44]. Two components of 1.1 and 83.3 ps represent the vibrational relaxation in the PT tautomer and the lifetime of PT tautomer in the excited state, respectively. Although a fast (~600 fs) kinetic component was observed at 590 nm where the strong ESA and SE signals cancel out, it is not clear whether this component represents the ESIPT dynamics of alizarin.
The Raman intensity of the FSRS, often called the Raman gain can be evaluated by Eq. (1):
RamanGain=IR.PumpONIBkgIR.PumpOFFIBkgE1
where IR.PumpONand IR.PumpOFFrepresent the intensity of Raman probe with and without the Raman pump, respectively, and IBkgrepresents the dark signal of the CCD detector. The Raman probe of 600,000 pulses (60 accumulations of 10-sec acquisition) was averaged in a typical Raman gain measurement with the half of them focused together with the Raman pump to the sample, to obtain a Raman gain signal in a signal-to-noise level of 2 × 10−5 (or 0.002%) at a specific time delay with the actinic pump pulses. Time-resolved stimulated Raman spectra of alizarin in DMSO at multiple time delays were obtained at time delays of −1 to 100 ps and the ground state spectrum measured at −10 ps time delay, for example, was subtracted from each stimulated Raman spectrum to obtain the difference stimulated Raman spectra shown in Figure 5(a). A small portion of transient absorption signal, for example, the ESA and SE can be obtained together with stimulated Raman gain signals at most time delays, thus a polynomial background subtraction was performed to remove the transient absorption signal.
#### 4.2.2. The population and structural dynamics of the ESIPT
Major Raman bands of the ground electronic state of alizarin in the 1500–1800 cm−1 range shown in Figure 5(a) were assigned as the ring ν(C=C) at 1573 and 1594 cm−1, and ν(C=O) at 1634 and 1661 cm−1 mainly according to the DFT simulation results. One ν(C=O) at 1661 cm−1 is assigned to the isolated carbonyl at C10 position and the other at 1634 cm−1 is the carbonyl at the site of the ESIPT and adjacent to a hydroxyl group [44]. Another Raman band at 1191 cm−1 is assigned as δ(CH) and δ(OH). In the excited stimulated Raman spectra of alizarin, several Raman bands at 1162, 1555, and 1632 cm−1 appeared in 50–100 fs after the photoexcitation and showed a decay after 20 ps or so. According to the TDDFT simulation results [23, 44], we tentatively assign the 1162 cm−1 band as the δ(CH) and δ(OH) of the PT tautomer, and the 1555 and 1632 cm−1 as ν(C=C) and ν(C=O) bands also in the PT tautomer of alizarin.
To obtain the details of the excited state dynamics and the ESIPT from the stimulated Raman bands of alizarin, the experimental data were fit with a low-order polynomial background and several Gaussian functions for Raman bands. The population dynamics of ν(C=C) and ν(C=O) bands at 1555 and 1632 cm−1 shown in Figure 5(b) shows a ubiquitous sharp rise in 70–80 fs and a slow decay into the ground state which is compatible to the PT tautomer’s lifetime of 83.3 ps as shown in the transient absorption results. The structural dynamics of ν(C=C) and ν(C=O) modes of the PT tautomer are shown in Figure 5(c) and (d) as the time-dependent changes in the peak position and the bandwidth. The peak shift of the solvent vibrational mode, δ(CH3) of DMSO at 1421 cm−1 represents the instrument response function of FSRS measurements for comparison with the excited dynamics of alizarin Raman bands. It is interesting to note that a strong blue-shift (1540 → 1553 cm−1) and a decrease of bandwidth (28 → 24 cm−1) of ν(C=C) band all occur in an ultrafast time scale of ~150 fs after photoexcitation. On the other hand, the ν(C=O) band shows a strong red-shift (1645 → 1630 cm−1) in the same time delay of 100–150 fs although this vibrational band appears too broad for the bandwidth analysis. As well represented in Figure 5(b–d), the population growth and the structural changes of ν(C=C) and ν(C=O) Raman bands of the PT tautomer of alizarin are interpreted as the ESIPT process from the LE to the PT tautomer. Since no Raman band of the LE tautomer has been identified from the FSRS results, this could also be included for the dynamics of ν(C=C) and ν(C=O) bands at 1555 and 1632 cm−1. The vibrational relaxation along an electronic potential surface would generally result in slight blue-shifts in the strongly coupled vibrational modes due to the anharmonicity of the electric potential surface. However, the ν(C=C) and ν(C=O) bands showed strong (~15 cm−1) peak shifts either in increasing and decreasing bandwidth, respectively, during the ultrafast period of the population growth for the PT tautomer. This cannot be explained by any type of relaxation inside the same potential surface but has to be understood as the nuclear rearrangements for the intramolecular proton transfer reaction. Therefore, we conclude that the intramolecular proton transfer reaction of alizarin in the excited state occurs in ultrafast time scale of 70–80 fs.
Another interesting fact is the strong and opposite peak shifts observed for ν(C=C) and ν(C=O) bands during the ESIPT reaction. We could imagine a transition state for the ESIPT reaction of alizarin as a six-membered ring formed by intramolecular hydrogen bonding between carbonyl group and hydroxyl group. We propose that the strong and opposite peak shifts of the ν(C=C) and ν(C=O) band directly represent the changes in the resonance structure of the alizarin backbone which is composed of multiple C=C and C-C bonds and a C=O. The details of the ESIPT reaction mechanism of alizarin need be confirmed by thorough theoreticalinvestigations, which is beyond of the scope of this chapter. The reaction mechanism of many ESIPT reactions and the existence of transition states have been recently reported by several theoretical works based on TDDFT and several transition states of six-membered ring between carbonyl and hydroxyl groups were represented for 1,8-dihydroxy-2-naphthaldehyde [7, 45, 46]. Although a separate transition state of the ESIPT reaction was not resolved from the FSRS results, we also propose the reaction may occur via the transition state of a new hydrogen-bond six-membered ring attached to the anthraquinone backbone.
As shown in Figure 5(b–d), two more kinetic components other than the population decay of the PT tautomer were identified. A slight blue-shift (1553 → 1557 cm−1) and an increased bandwidth (24 → 26 cm−1) of ν(C=C) mode observed in 3–10 ps and another slight blue-shift (1630 → 1636 cm−1) of ν(C=O) mode shown in 20–30 ps represent the vibrational relaxation in the product potential surface of the PT conformer. There were no further changes in peak position and bandwidth of ν(C=C) and ν(C=O) modes during the population decay of the PT tautomer, which also supports the assignment of the vibrational relaxation in the PT potential surface.
## 5. Solvation dynamics
The intramolecular proton transfer reaction of alizarin in the excited state was evidenced by the population and structural dynamics of two major vibrational modes of ν(C=C) and ν(C=O). Ultrafast ESIPT reaction of alizarin in the excited state can also be observed indirectly by the changes in the solvent vibrational spectrum such as the instantaneous disruption of the solvation shells and the formation of new solvation. Figure 6(a) and (b) show the difference stimulated Raman spectra of the solvent DMSO, especially ν(S=O) at 1044 cm−1 with alizarin concentrations of 20 and 1 mM, respectively. Solvent DMSO is known to form hydrogen bonds in solution between S=O and C-H groups, and also a polymeric structure is formed at low temperature [47]. The Raman band of ν(S=O) is composed of multiple subbands including the symmetric (1026 cm−1) and antisymmetric stretching (1042 cm−1) of dimer, the symmetric stretching (1058 cm−1) of monomer, etc., [47, 48]. In the DMSO solutions of alizarin in 0–15 mM concentration range, the ν(S=O) band of DMSO shows strong peak shifts (1042 → 1024 cm−1), which represents changes in the hydrogen bonding network of DMSO [44]. The δ(CH3) band of DMSO shows no major spectral changes upon the alizarin concentration, thus the solvation of alizarin with DMSO mainly occurs via hydrogen bonds with the sulfoxide group of DMSO [44].
As shown in Figure 6(a) and (b), a sharp dispersive pattern in the ν(S=O) band appears instantly with the actinic pulse for both 20 and 1 mM concentrations of alizarin. The Raman intensity for the symmetric stretching of monomer around 1060 cm−1 decreases and the symmetric stretching of dimer around 1025 cm−1 increases, which clearly shows the instantaneous changes in hydrogen bonding of DMSO molecules. As clearly seen with the 1-mM solution case, this dispersive pattern disappears very quickly as the actinic pulse leaves the solution. In other words, a disruption in the hydrogen bonding of DMSO molecules created by ultrafast laser pulses is removed quickly by reforming hydrogen bonds between DMSO molecules. It seems that the hydrogen bond reformation occurs much faster than the instrument response function of FSRS (~100 fs). Considering from the ultrafast dynamics of the dispersive signals of ν(S=O) band, the nonpolar solvation effect may be understood as the origin of this sharp dispersive signal [49, 50, 51]. We have also observed a similar dispersive background signal in the δ(CH3) band of DMSO [44].
On the other hand, the 20-mM alizarin results showed clearly distinct dynamics for the ν(S=O) band as shown in Figure 6(a). The initial dispersive Raman signals were almost removed in about 100 fs then another type of dispersive Raman signals appeared, which is composed of a small bleaching with almost the same spectral shape as the ground state ν(S=O) band and a much broader positive signal around 990 cm−1. Figure 7 clearly shows this dispersive Raman pattern in the ν(S=O) of DMSO appearing 100 fs after the actinic pump, where the initial dispersive Raman signals of the ν(S=O) obtained with 1-mM alizarin solution were subtracted from the results with 20-mM alizarin solution. The bleaching of the ground state ν(S=O) Raman band may result from the local heating due to the vibrational cooling of solute molecules, then the recovery of the bleaching signals by the local cooling would take several tens of picoseconds [51, 52, 53]. The decay of the second dispersive Raman signals at 990 and 1043 cm−1 is compatible to the local cooling time but a huge frequency difference (~50 cm−1) cannot be explained by the local heating of solvent DMSO. In a control experiment to measure temperature-dependent Raman spectra for the ν(S=O) of DMSO, the spectral changes of less than 5 cm−1 were observed with temperature increase of 40–50 °C. Therefore, we conclude that the second dispersive Raman signals of ν(S=O) appearing at 100 fs time delay and between 990 and 1043 cm−1 cannot be explained as the local heating of solvent molecules pumped by vibrationally cooled solute molecules and the changes in the solvation shells of DMSO molecules due to the ESIPT reaction of alizarin molecules from the LE to the PT tautomers must be considered. Different from the initial dispersive signals in the ν(S=O) and δ(CH3) bands of DMSO, the second dispersive signals in the ν(S=O) must be considered as originating from the polar or dielectric type of solvation [51]. The dispersive Raman signal of the ν(S=O) band at 1044 cm−1 showed a growth with a 60 ± 30 fs time constant and a decay with a 4.9 ± 1.5 ps time constant, which clearly shows that the hydrogen-bonding network of DMSO was created by the ESIPT reaction of alizarin and decayed as the vibrational relaxation of the product along the potential surface of the PT tautomer in the excited state. In this work, we showed that the ν(S=O) band of solvent DMSO can be used to determine the ultrafast ESIPT reaction and the subsequent vibrational relaxation in the reaction product. The breaking and reforming of hydrogen-bonding network of DMSO can be successfully observed by the ν(S=O) band of DMSO thus this method can also be applied to many chemical reactions occurring in the photoinduced excited states.
## 6. Conclusion
In this chapter, the ESIPT reaction and the excited state dynamics of alizarin were explored by time-resolved electronic and vibrational spectroscopy with the femtosecond time-resolution. The dependence on solvent polarity and excitation wavelength was observed in the steady-state emission spectra of alizarin, where the barrier height between the LE and PT tautomers in the excited state may exist and be controlled by the solvent polarity. The transient absorption results of alizarin in ethanol and ethanol-water mixture were so complicated and overlapping, so the ESIPT rate constant from the LE to the PT tautomers was not separable from the vibrational relaxation and population decay of both tautomers. Instead, the ESIPT of alizarin in the excited state was clearly observed in femtosecond stimulated Raman measurements. The population and structural dynamics of two major vibrational modes of ν(C=C) and ν(C=O) clearly showed the dynamics of the ESIPT rate to the PT tautomer, the vibrational relaxation and the population decay of the product PT tautomer. The vibrational signature of the LE tautomer was not observed in FSRS, but the reaction mechanism of the ESIPT including a transition state of a newly formed six-membered ring composed of the carbonyl and hydroxyl groups was estimated by the strong and opposite peak shifts of ν(C=C) and ν(C=O) seen in the stimulated Raman spectra of alizarin during the reaction. From the population growth and structural transformation into the PT tautomer, we concluded that the ESIPT of alizarin occurs in an ultrafast time scale of 70–80 fs. During the ESIPT reaction of alizarin, solvent DMSO molecules showed ultrafast structural changes involving hydrogen bonds with solute molecules. When the solute concentration is very low, DMSO shows a dispersive Raman signal in the ν(S=O) and δ(CH3) modes only with the actinic pump. The instantaneous disruption and reformation of hydrogen bonds may suggest a nonpolar type of solvation between solvent molecules. On the other hand, complicated dispersive Raman signals in the ν(S=O) mode of DMSO were observed with a concentrated (20 mM) solution of alizarin. After the same instantaneous solvent responses completed in 100 fs, the second dispersive Raman pattern with a bleaching of the ground state spectrum appeared and decayed with 60 fs and 5 ps time scales. This also represents the disruption of hydrogen bonds of DMSO molecules, more specifically between solute molecules and in the polar or dielectric solvation shells. Interestingly, the dynamics for the ultrafast proton transfer reaction and the vibrational relaxation in the product state was measured by the solvation signals of solvent DMSO.
## Acknowledgments
This work was supported by Basic Science Research Program funded by the Ministry of Education (2017R1A1D1B03027870, 2014R1A1A2058409) and by the International Cooperation Program (2016K2A9A1A01951845), through the National Research Foundation of Korea (NRF). The GIST Research Institute (GRI) in 2018 and the PLSI supercomputing resources of the Korea Institute of Science and Technology Information also supported this research.
## Conflict of interest
The authors declare no conflict of interest.
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Sebok Lee, Myungsam Jen, Kooknam Jeon, Jaebeom Lee, Joonwoo Kim and Yoonsoo Pang (March 27th 2018). Ultrafast Intramolecular Proton Transfer Reaction of 1,2- Dihydroxyanthraquinone in the Excited State, Photochemistry and Photophysics - Fundamentals to Applications, Satyen Saha and Sankalan Mondal, IntechOpen, DOI: 10.5772/intechopen.75783. Available from:
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https://worldwidescience.org/topicpages/a/adult+human+thymus.html | #### Sample records for adult human thymus
1. Essential Microenvironment for Thymopoiesis is Preserved in Human Adult and Aged Thymus
Directory of Open Access Journals (Sweden)
J. Shiraishi
2003-01-01
Full Text Available Normal human thymuses at various ages were immunohistologically examined in order to determine whether adult or aged thymus maintained the microenvironment for the T cell development and thymopoiesis was really ongoing. To analyze the thymic microenvironment, two monoclonal antibodies (MoAb were employed. One is MoAb to IL-1 receptor (IL-1R recognizing medullary and subcapsular cortical epithelial cells of normal infant human thymus. The other is UH-1 MoAb recognizing thymic epithelial cells within the cortex, which are negative with IL-1R-MoAb. Thymus of subjects over 20 years of age was split into many fragments and dispersed in the fatty tissue. However, the microenvironment of each fragment was composed of both IL-1R positive and UH-1 positive epithelial cells, and the UH-1 positive portion was populated with lymphocytes showing a follicle-like appearance. Lymphocytes in these follicle-like portions were mostly CD4+CD8+ double positive cells and contained many proliferating cells as well as apoptotic cells. Thus these follicle-like portions in adult and aged thymus were considered to be functioning as cortex as in infant thymus. Proliferative activity of thymocytes in the thymic cortex and the follicle-like portions definitely declined with advance of age, while incidence of apoptotic thymocytes increased with aging.
2. MORPHOLOGICAL FEATURES AND MORPHOMETRIC PARAMETERS OF HUMAN FETAL THYMUS GLANDS
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S. Havila Hasini
2014-03-01
Full Text Available Introduction: Thymus is one of the central lymphoid organs. It plays an important role in the differentiation, selection and maturation of T-lymphocytes. In the recent years morphology and morphometry of the thymus gland in the newborn is gaining significance as it demonstrates great variability between individual infants and in the same infant at different times. Materials and methods: In the present study 45 thymus specimens from aborted human fetuses of 16 to 40 weeks gestational age and both sexes were studied by autopsy for morphological and morphometric features. The morphometric parameters were measured using pachymeter. Results: The thymus gland was located in the superior mediastinum. 60% (27/45 specimens showed cervical extensions. Brachiocephalic vein anterior to thymus was observed in 3 cases which is an important anomaly to be observed in thymectomy procedure. Thymuses were greyish pink to greyish brown in colour. Variations were also observed in the number of lobes of glands in which one is single lobed, most of the glands are bilobed and few are trilobed. There is progressive increase in all morphometric dimensions of the thymus in relation to gestational age. Most of the specimens were less than 4cm in length. Half of the specimens were below 2cm in width and other half were 2.0 to 5.0 cm in width. For 90% of the specimens thickness of the organ was less than 0.5cm. The thymus gland was 0.2% of fetal body weight. Conclusion: The morphological observations of thymus gland shows great variations which has to be considered in thymectomy. In addition to anthropometric parameters of fetus, morphometric parameters of thymus glands present significant relation to the gestational age of fetuses. It is possible to determine the thymic morphometric parameters in relation to gestational age.
3. Thymus Gland Anatomy
Science.gov (United States)
4. Identification of a Bipotent Epithelial Progenitor Population in the Adult Thymus
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Svetlana Ulyanchenko
2016-03-01
Full Text Available Thymic epithelial cells (TECs are critically required for T cell development, but the cellular mechanisms that maintain adult TECs are poorly understood. Here, we show that a previously unidentified subpopulation, EpCam+UEA1−Ly-51+PLET1+MHC class IIhi, which comprises <0.5% of adult TECs, contains bipotent TEC progenitors that can efficiently generate both cortical (c TECs and medullary (m TECs. No other adult TEC population tested in this study contains this activity. We demonstrate persistence of PLET1+Ly-51+ TEC-derived cells for 9 months in vivo, suggesting the presence of thymic epithelial stem cells. Additionally, we identify cTEC-restricted short-term progenitor activity but fail to detect high efficiency mTEC-restricted progenitors in the adult thymus. Our data provide a phenotypically defined adult thymic epithelial progenitor/stem cell that is able to generate both cTECs and mTECs, opening avenues for improving thymus function in patients.
5. Multilineage Potential and Self-Renewal Define an Epithelial Progenitor Cell Population in the Adult Thymus
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Kahlia Wong
2014-08-01
Full Text Available Thymic epithelial cells (TECs are critical for T cell development and self-tolerance but are gradually lost with age. The existence of thymic epithelial progenitors (TEPCs in the postnatal thymus has been inferred, but their identity has remained enigmatic. Here, we assessed the entire adult TEC compartment in order to reveal progenitor capacity is retained exclusively within a subset of immature thymic epithelium displaying several hallmark features of stem/progenitor function. These adult TEPCs generate mature cortical and medullary lineages in a stepwise fashion, including Aire+ TEC, within fetal thymus reaggregate grafts. Although relatively quiescent in vivo, adult TEPCs demonstrate significant in vitro colony formation and self-renewal. Importantly, 3D-cultured TEPCs retain their capacity to differentiate into cortical and medullary TEC lineages when returned to an in vivo thymic microenvironment. No other postnatal TEC subset exhibits this combination of properties. The characterization of adult TEPC will enable progress in understanding TEC biology in aging and regeneration.
6. Expression of 11beta-hydroxysteroid-dehydrogenase type 2 in human thymus.
Science.gov (United States)
Almanzar, Giovanni; Mayerl, Christina; Seitz, Jan-Christoph; Höfner, Kerstin; Brunner, Andrea; Wild, Vanessa; Jahn, Daniel; Geier, Andreas; Fassnacht, Martin; Prelog, Martina
2016-06-01
11beta-hydroxysteroid-dehydrogenase type 2 (11β-HSD2) is a high affinity dehydrogenase which rapidly inactivates physiologically-active glucocorticoids to protect key tissues. 11β-HSD2 expression has been described in peripheral cells of the innate and the adaptive immune system as well as in murine thymus. In absence of knowledge of 11β-HSD2 expression in human thymus, the study aimed to localize 11β-HSD2 in human thymic tissue. Thymic tissue was taken of six healthy, non-immunologically impaired male infants below 12months of age with congenital heart defects who had to undergo correction surgery. 11β-HSD2 protein expression was analyzed by immunohistochemistry and Western blot. Kidney tissue, peripheral blood mononuclear cells (PBMCs) and human umbilical vein endothelial cells (HUVEC) were taken as positive controls. Significant expression of 11β-HSD2 protein was found at single cell level in thymus parenchyma, at perivascular sites of capillaries and small vessels penetrating the thymus lobuli and within Hassall's bodies. The present study demonstrates that 11β-HSD2 is expressed in human thymus with predominant perivascular expression and also within Hassall's bodies. To our knowledge, this is the first report confirming 11β-HSD2 expression at the protein level in human thymic tissue underlining a potential role of this enzyme in regulating glucocorticoid function at the thymic level. PMID:27025972
7. COMPARATIVE MORPHOLOGICAL AND ANATOMICAL STUDY ON THYMUS GLAND OF HUMAN AND PRIMATE
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P. Devi Raja Rajeswari,
2014-09-01
Full Text Available Context: The comparative morphological and anatomical study on thymus was carried out in human and primate. The prenatal stage of Macaca radiata was selected for the present study. Study Design: Cross sectional analytical type of study. Place and Period of study: Department of Anatomy, Dr. A.L.M. PG Institute of Basic Medical Sciences, Chennai from July 1999 to June 2000. Materials: The comparative morphology and anatomy of thymus of human embryonic, 10 weeks, 15 weeks and prenatal foetuses, and monkey foetus was carried out. Methods: Comparative micro-anatomical study was done by paraffin processing method. The sections were stained as per the method published by Culling (1974. Results: In monkey foetus, the thymus gland is slightly elongated, whereas in human foetuses it is not elongated and oval in shape. The size of the thymus is larger in human foetuses than monkey foetus. In both cases cells are parenchymal in nature. Due to spatial organization in human foetuses, the lymphocytes aggregation is more in cortex than in medulla. In monkey foetus the lymphocyte aggregation is simpler in arrangement through spatial organization is much less.
8. Normal thymus in adults: appearance on CT and associations with age, sex, BMI and smoking
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Araki, Tetsuro [Harvard Medical School, Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women' s Hospital, Boston, MA (United States); Kinki University Faculty of Medicine, Department of Radiology, Osaka-Sayama (Japan); Nishino, Mizuki; Hatabu, Hiroto [Harvard Medical School, Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women' s Hospital, Boston, MA (United States); Gao, Wei [Boston University School of Public Health, Department of Biostatistics, Boston, MA (United States); Dupuis, Josee [Boston University School of Public Health, Department of Biostatistics, Boston, MA (United States); The National Heart Lung and Blood Institute' s Framingham Heart Study, Framingham, MA (United States); Hunninghake, Gary M.; Washko, George R. [Harvard Medical School, The Pulmonary and Critical Care Division, Brigham and Women' s Hospital, Boston, MA (United States); Murakami, Takamichi [Kinki University Faculty of Medicine, Department of Radiology, Osaka-Sayama (Japan); O' Connor, George T. [The National Heart Lung and Blood Institute' s Framingham Heart Study, Framingham, MA (United States); Boston University School of Medicine, Pulmonary Center and Department of Medicine, Boston, MA (United States)
2016-01-15
To investigate CT appearance and size of the thymus in association with participant characteristics. 2540 supposedly healthy participants (mean age 58.9 years, 51 % female) were evaluated for the CT appearance of thymic glands with four-point scores (according to the ratio of fat and soft tissue), size and morphology. These were correlated with participants' age, sex, BMI and smoking history. Of 2540 participants, 1869 (74 %) showed complete fatty replacement of the thymus (Score 0), 463 (18 %) predominantly fatty attenuation (Score 1), 172 (7 %) half fatty and half soft-tissue attenuation (Score 2) and 36 (1 %) solid thymic gland with predominantly soft-tissue attenuation (Score 3). Female participants showed less fatty degeneration of the thymus with higher thymic scores within age 40-69 years (P < 0.001). Participants with lower thymic scores showed higher BMI (P < 0.001) and were more likely to be former smokers (P < 0.001) with higher pack-years (P = 0.04). Visual assessment with four-point thymic scores revealed a sex difference in the fatty degeneration of the thymus with age. Women show significantly higher thymic scores, suggesting less fat content of the thymus, during age 40-69 years. Cigarette smoking and high BMI are associated with advanced fatty replacement of the thymus. (orig.)
9. Normal thymus in adults: appearance on CT and associations with age, sex, BMI and smoking
International Nuclear Information System (INIS)
To investigate CT appearance and size of the thymus in association with participant characteristics. 2540 supposedly healthy participants (mean age 58.9 years, 51 % female) were evaluated for the CT appearance of thymic glands with four-point scores (according to the ratio of fat and soft tissue), size and morphology. These were correlated with participants' age, sex, BMI and smoking history. Of 2540 participants, 1869 (74 %) showed complete fatty replacement of the thymus (Score 0), 463 (18 %) predominantly fatty attenuation (Score 1), 172 (7 %) half fatty and half soft-tissue attenuation (Score 2) and 36 (1 %) solid thymic gland with predominantly soft-tissue attenuation (Score 3). Female participants showed less fatty degeneration of the thymus with higher thymic scores within age 40-69 years (P < 0.001). Participants with lower thymic scores showed higher BMI (P < 0.001) and were more likely to be former smokers (P < 0.001) with higher pack-years (P = 0.04). Visual assessment with four-point thymic scores revealed a sex difference in the fatty degeneration of the thymus with age. Women show significantly higher thymic scores, suggesting less fat content of the thymus, during age 40-69 years. Cigarette smoking and high BMI are associated with advanced fatty replacement of the thymus. (orig.)
10. Location of T cell and major histocompatibility complex antigens in the human thymus
OpenAIRE
1980-01-01
A series of monoclonal antibodies were used to study the intrathymic distribution of T cell-specific antigens, Ia antigens, and beta 2- microglobulin in frozen sections of human thymus by immunofluorescence and immunoperoxidase techniques. Most of the cortical thymocytes reacted with anti-T4, anti-T5, anti-T6, anti-T8, and anti-T10 antibodies, thus indicating coexpression of multiple antigens on cortical lymphocytes. The staining of cells in the medulla was most satisfactorily judged in secti...
11. Thymus Cancer
Science.gov (United States)
... cell. These cells help protect you from infections. Cancer of the thymus is rare. You are more ... Sometimes there are no symptoms. Other times, thymus cancer can cause A cough that doesn't go ...
12. A discrete population of IFN λ-expressing BDCA3hi dendritic cells is present in human thymus.
Science.gov (United States)
Martínez, Víctor G; Canseco, Noelia M; Hidalgo, Laura; Valencia, Jaris; Entrena, Ana; Fernández-Sevilla, Lidia M; Hernández-López, Carmen; Sacedón, Rosa; Vicente, Angeles; Varas, Alberto
2015-08-01
Human thymus contains two major subpopulations of dendritic cells (DCs), conventional DCs (cDCs) and plasmacytoid DCs (pDCs), which are mainly involved in central tolerance and also in protecting the thymus against infections. In blood and peripheral organs cDCs include the subpopulation of BDCA3(hi) DCs, considered as equivalents to mouse CD8α(+) DCs. In this study we describe in human thymus the presence of a discrete population of BDCA3(hi) DCs that, like their peripheral counterparts, express CD13, low-intermediate levels of CD11c, CLEC9A, high levels of XCR1, IRF8 and TLR3, and mostly lack the expression of CD11b, CD14 and TLR7. Thymic BDCA3(hi) DCs display immature features with a low expression of costimulatory molecules and HLA-DR, and a low allostimulatory capacity. Also, BDCA3(hi) DCs exhibit a strong response to TLR3 stimulation, producing high levels of interferon (IFN)-λ1 and CXCL10, which indicates that, similarly to thymic pDCs, BDCA3(hi) DCs can have an important role in thymus protection against viral infections. PMID:25753268
13. Effect of Thymus vulgaris oil on some reproductive characters in adult male rats
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S. J. Kakel
2008-01-01
Full Text Available The study was undertaken to show the effect of thymus vulgaris oil administration at (0.3, 0.6 ml/kg orally for 60 days on male fertility and epididymal sperms characters in male rats at age of 100 days. The animals treated with thyme oil at a dose of (0.6 ml revealed a significant decrease in the weight of testes, body of epididymis, percentage of live/dead sperms and epididymyal sperm count, with a significant increase in the percentage of morphologically abnormal sperms. On the other hand the animals treated with thyme oil at a dose (0.3 ml show a significant decrease in the weight of body of epididymis, epididymal sperm count and the percentage of live/dead sperms accompanied with a significant increase in the percentage of morphologically abnormal sperms. Its concluded from this study that thymus vulgaris has an inhibitory effect on reproductive system and spermatogenesis in mature male rats.
OpenAIRE
Haas, Lenneke E. M.; Steven F. T. Thijsen; Leontine van Elden; Heemstra, Karen A.
2013-01-01
Human metapneumovirus (HMPV) is a relative newly described virus. It was first isolated in 2001 and currently appears to be one of the most significant and common human viral infections. Retrospective serologic studies demonstrated the presence of HMPV antibodies in humans more than 50 years earlier. Although the virus was primarily known as causative agent of respiratory tract infections in children, HMPV is an important cause of respiratory infections in adults as well. Almost all children ...
15. Medullary Epithelial Cells of the Human Thymus Express a Highly Diverse Selection of Tissue-specific Genes Colocalized in Chromosomal Clusters
OpenAIRE
Gotter, Jörn; Brors, Benedikt; Hergenhahn, Manfred; Kyewski, Bruno
2004-01-01
Promiscuous expression of tissue-specific self-antigens in the thymus imposes T cell tolerance and protects from autoimmune diseases, as shown in animal studies. Analysis of promiscuous gene expression in purified stromal cells of the human thymus at the single and global gene level documents the species conservation of this phenomenon. Medullary thymic epithelial cells overexpress a highly diverse set of genes (>400) including many tissue-specific antigens, disease-associated autoantigens, a...
16. Ionizing radiation and the thymus
International Nuclear Information System (INIS)
In this thesis the effects of whole body irradiation with fast fission neutrons and X-rays on the murine thymus are studied. Young adult CBA mice were exposed to whole body irradiation with either fast fission neutrons or X-rays. The results of the investigation of short- and long-term effects of the irradiation on the thymus showed a biphasic regeneration pattern followed by a marked decrease in relative thymus weight and cellularity which lasted up to at least 250 days. This late effect is attributed to possible loss of pluripotent stem cells and residual damage in the surviving stem cells in the bone marrow. The immunohistology of T cell subpopulations in the thymus of normal CBA/H mice was analyzed in order to describe the T cell composition of the irradiated thymus. The effects of irradiation with fast fission neutrons on the stromal cells of the thymus are studied in order to investigate whether the thymic stromal cells are involved in the regeneration process. The effect of graded doses of fission neutrons or X-rays on the lymphoid compartment on the thymus are studied in order to investigate the radiosensitivity of thymocyte subpopulations for these radiation types. Also the effects on the stromal compartment of the thymus are investigated. (Auth.)
17. Histo-blood group antigens in human fetal thymus and in thymomas
DEFF Research Database (Denmark)
Engel, P; Dabelsteen, Erik; Francis, D;
1996-01-01
-y, Le-x and sialyl-Le-x) of the ABO-histo-blood group system was investigated in 19 normal fetal thymuses (gestational age 16 to 39 weeks) and in 19 thymomas in order to study possible tumor-associated changes in the glycosylation pattern. The material was investigated by immunochemical stainings...
Directory of Open Access Journals (Sweden)
Lenneke E. M. Haas
2013-01-01
Full Text Available Human metapneumovirus (HMPV is a relative newly described virus. It was first isolated in 2001 and currently appears to be one of the most significant and common human viral infections. Retrospective serologic studies demonstrated the presence of HMPV antibodies in humans more than 50 years earlier. Although the virus was primarily known as causative agent of respiratory tract infections in children, HMPV is an important cause of respiratory infections in adults as well. Almost all children are infected by HMPV below the age of five; the repeated infections throughout life indicate transient immunity. HMPV infections usually are mild and self-limiting, but in the frail elderly and the immunocompromised patients, the clinical course can be complicated. Since culturing the virus is relatively difficult, diagnosis is mostly based on a nucleic acid amplification test, such as reverse transcriptase polymerase chain reaction. To date, no vaccine is available and treatment is supportive. However, ongoing research shows encouraging results. The aim of this paper is to review the current literature concerning HMPV infections in adults, and discuss recent development in treatment and vaccination.
Science.gov (United States)
Haas, Lenneke E M; Thijsen, Steven F T; van Elden, Leontine; Heemstra, Karen A
2013-01-01
Human metapneumovirus (HMPV) is a relative newly described virus. It was first isolated in 2001 and currently appears to be one of the most significant and common human viral infections. Retrospective serologic studies demonstrated the presence of HMPV antibodies in humans more than 50 years earlier. Although the virus was primarily known as causative agent of respiratory tract infections in children, HMPV is an important cause of respiratory infections in adults as well. Almost all children are infected by HMPV below the age of five; the repeated infections throughout life indicate transient immunity. HMPV infections usually are mild and self-limiting, but in the frail elderly and the immunocompromised patients, the clinical course can be complicated. Since culturing the virus is relatively difficult, diagnosis is mostly based on a nucleic acid amplification test, such as reverse transcriptase polymerase chain reaction. To date, no vaccine is available and treatment is supportive. However, ongoing research shows encouraging results. The aim of this paper is to review the current literature concerning HMPV infections in adults, and discuss recent development in treatment and vaccination. PMID:23299785
20. Different patterns of nicotinic acetylcholine receptor subunit transcription in human thymus.
Science.gov (United States)
Bruno, Roxana; Sabater, Lidia; Tolosa, Eva; Sospedra, Mireia; Ferrer-Francesch, Xavier; Coll, Jaume; Foz, Marius; Melms, Arthur; Pujol-Borrell, Ricardo
2004-04-01
Clinical observations suggest that the thymus is strongly implicated in the pathogenesis of myasthenia gravis (MG), but questions such as the level and location of nicotinic acetylcholine receptor (AChR) subunit expression that are fundamental to postulate any pathogenic mechanism, remain controversial. We have re-examined this question by combining calibrated RT-PCR and real-time PCR to study nicotinic AChR subunit mRNA expression in a panel of normal and myasthenic thymi. The results suggest that the expression of the different AChR subunits follows three distinct patterns: constitutive for, neonatal for gamma and individually variable for alpha1, beta1 and delta. Experiments using confocal laser microdissection suggest that AChR is mainly expressed in the medullary compartment of the thymus but there is not a clear compartmentalization of subunit expression. The different patterns of subunit expression may influence decisively the level of central tolerance to the subunits and explain the focusing of the T cell response to the alpha and gamma subunits. PMID:15020075
1. Chemical composition, larvicidal evaluation, and adult repellency of endemic Greek Thymus essential oils against the mosquito vector of West Nile virus.
Science.gov (United States)
Pitarokili, Danae; Michaelakis, Antonios; Koliopoulos, George; Giatropoulos, Athanassios; Tzakou, Olga
2011-08-01
The volatile metabolites of Greek wild growing Thymus leucospermus and Thymus teucrioides subsp. candilicus were determined by gas chromatography and gas chromatography-mass spectrometry. The monoterpene hydrocarbon p-cymene (64.2%) dominated T. leucospermus oil, followed by γ-terpinene (7.9%), thymol (4.8%), and borneol (4.7%), whereas the most abundant constituents in T. teucrioides subsp. candilicus oil were p-cymene (25.5%), γ-terpinene (19.0%), thymol (18.8%), borneol (5.7%), and α-pinene (5.7%). The larvicidal and repellent activities of the analyzed essential oils were tested on Culex pipiens larvae and adults, respectively. Additionally, the main metabolite of the essential oils, p-cymene was tested against C. pipiens adults in order to define the affiliation between p-cymene and the repellent properties of the oil. The essential oils of T. leucospermus and T. teucrioides subsp. candilicus provided repellency 78.1% and 72.9%, respectively, statistically equal to the reference product icaridin. The compound p-cymene showed almost no repellent activity. The essential oil of T. leucospermus presented lower larvicidal activity (LC(50) = 34.26 mgl(-1)) against C. pipiens third-fourth instar larvae while T. teucrioides subsp. candilicus was the most active with an estimated LC(50) value of 23.17 mgl(-1). PMID:21301870
2. Proapoptotic and Antiproliferative Effects of Thymus caramanicus on Human Breast Cancer Cell Line (MCF-7 and Its Interaction with Anticancer Drug Vincristine
Directory of Open Access Journals (Sweden)
Saeed Esmaeili-Mahani
2014-01-01
Full Text Available Thymus caramanicus Jalas is one of the species of thymus that grows in the wild in different regions of Iran. Traditionally, leaves of this plant are used in the treatment of diabetes, arthritis, and cancerous situation. Therefore, the present study was designed to investigate the selective cytotoxic and antiproliferative properties of Thymus caramanicus extract (TCE. MCF-7 human breast cancer cells were used in this study. Cytotoxicity of the extract was determined using MTT and neutral red assays. Biochemical markers of apoptosis (caspase 3, Bax, and Bcl-2 and cell proliferation (cyclin D1 were evaluated by immunoblotting. Vincristine was used as anticancer control drug in extract combination therapy. The data showed that incubation of cells with TCE (200 and 250 μg/mL significantly increased cell damage, activated caspase 3 and Bax/Bcl2 ratio. In addition, cyclin D1 was significantly decreased in TCE-treated cells. Furthermore, concomitant treatment of cells with extract and anticancer drug produced a significant cytotoxic effect as compared to extract or drugs alone. In conclusion, thymus extract has a potential proapoptotic/antiproliferative property against human breast cancer cells and its combination with chemotherapeutic agent vincristine may induce cell death effectively and be a potent modality to treat this type of cancer.
3. Radiation and host factors in human thyroid tumors following thymus irradiation
International Nuclear Information System (INIS)
4. Inhibition of Acute in vivo Human Immunodeficiency Virus Infection by Human Interleukin 10 Treatment of SCID Mice Implanted with Human Fetal Thymus and Liver
Science.gov (United States)
Kollmann, Tobias R.; Pettoello-Mantovani, Massimo; Katopodis, Nikos F.; Hachamovitch, Moshe; Rubinstein, Arye; Kim, Ana; Goldstein, Harris
1996-04-01
To improve the usefulness of in vivo models for the investigation of the pathophysiology of human immunodeficiency virus (HIV) infection, we modified the construction of SCID mice implanted with human fetal thymus and liver (thy/liv-SCID-hu mice) so that the peripheral blood of the mice contained significant numbers of human monocytes and T cells. After inoculation with HIV-159, a primary patient isolate capable of infecting monocytes and T cells, the modified thy/liv-SCID-hu mice developed disseminated HIV infection that was associated with plasma viremia. The development of plasma viremia and HIV infection in thy/liv-SCID-hu mice inoculated with HIV-159 was inhibited by acute treatment with human interleukin (IL) 10 but not with human IL-12. The human peripheral blood mononuclear cells in these modified thy/liv-SCID-hu mice were responsive in vivo to treatment with exogenous cytokines. Human interferon γ expression in the circulating human peripheral blood mononuclear cells was induced by treatment with IL-12 and inhibited by treatment with IL-10. Thus, these modified thy/liv-SCID-hu mice should prove to be a valuable in vivo model for examining the role of immunomodulatory therapy in modifying HIV infection. Furthermore, our demonstration of the in vivo inhibitory effect of IL-10 on acute HIV infection suggests that further studies may be warranted to evaluate whether there is a role for IL-10 therapy in preventing HIV infection in individuals soon after exposure to HIV such as for children born to HIV-infected mothers.
5. The size of the thymus: an important immunological diagnostic tool?
DEFF Research Database (Denmark)
Jeppesen, Dorthe Lisbeth
2003-01-01
thymus relevant to its function and could measurement of the thymus be a useful immunological diagnostic tool in the investigation of thymic function in humans with a depressed immune system? Conclusion: Studies using the size of the thymus as an immunological diagnostic tool should be encouraged....
6. The SCID-hu mouse as a tool in immunotoxicological risk assessment: effects of 2-acetyl-4(5)-tetrahydroxybutyl-imidazole (THI) and di-n-butyltin dichloride (DBTC) on the human thymus in SCID-hu mice.
Science.gov (United States)
de Heer, C; Schuurman, H J; Houben, G F; Pieters, R H; Penninks, A H; van Loveren, H
1995-06-26
SCID mice engrafted with human fetal thymus and liver tissue fragments (SCID-hu mice) are currently considered as a new tool in human immunotoxicological risk assessment. Testing of various immunotoxicants exerting thymotoxicity via different intrathymic target cell types is necessary for validation of this model. Therefore, SCID-hu mice were exposed to 2-acetyl-4(5)-(1,2,3,4-tetrahydroxybutyl)-imidazole (THI), the immunotoxic component in the food additive, Caramel Colour III, or the organotin compound, di-n-butyltin dichloride (DBTC). Histopathological examination of the human thymus grafts of SCID-hu mice either exposed to THI or to DBTC showed a reduction in the relative size of the thymus cortex, an effect also described in rodents. These results indicate that the human thymus is a target for the immunotoxic action of both THI and DBTC. In addition, they indicate the promising potential of the SCID-hu mouse model as a tool for human immunotoxicological risk assessment. PMID:7624878
7. Thymus dependent immune competence
International Nuclear Information System (INIS)
Studies are described which are concerned with changes in cellular immunocompetance in ageing and tumour-bearing animals. The possible therapeutical application of thymic humoral factors in restoration of diminished T cell functions initiated the more fundamental studies on the humoral function of the thymus are also described. Irradiated mice and rats were used. (Auth.)
8. Comparison between human fetal and adult skin
OpenAIRE
Coolen, N.A.; Schouten, K.C.; Middelkoop, E.; Ulrich, M.
2009-01-01
Healing of early-gestation fetal wounds results in scarless healing. Since the capacity for regeneration is probably inherent to the fetal skin itself, knowledge of the fetal skin composition may contribute to the understanding of fetal wound healing. The aim of this study was to analyze the expression profiles of different epidermal and dermal components in the human fetal and adult skin. In the human fetal skin (ranging from 13 to 22 weeks’ gestation) and adult skin biopsies, the expression...
9. Transcriptomic analysis supports similar functional roles for the two thymuses of the tammar wallaby
Directory of Open Access Journals (Sweden)
Renfree Marilyn B
2011-08-01
Full Text Available Abstract Background The thymus plays a critical role in the development and maturation of T-cells. Humans have a single thoracic thymus and presence of a second thymus is considered an anomaly. However, many vertebrates have multiple thymuses. The tammar wallaby has two thymuses: a thoracic thymus (typically found in all mammals and a dominant cervical thymus. Researchers have known about the presence of the two wallaby thymuses since the 1800s, but no genome-wide research has been carried out into possible functional differences between the two thymic tissues. Here, we used pyrosequencing to compare the transcriptomes of a cervical and thoracic thymus from a single 178 day old tammar wallaby. Results We show that both the tammar thoracic and the cervical thymuses displayed gene expression profiles consistent with roles in T-cell development. Both thymuses expressed genes that mediate distinct phases of T-cells differentiation, including the initial commitment of blood stem cells to the T-lineage, the generation of T-cell receptor diversity and development of thymic epithelial cells. Crucial immune genes, such as chemokines were also present. Comparable patterns of expression of non-coding RNAs were seen. 67 genes differentially expressed between the two thymuses were detected, and the possible significance of these results are discussed. Conclusion This is the first study comparing the transcriptomes of two thymuses from a single individual. Our finding supports that both thymuses are functionally equivalent and drive T-cell development. These results are an important first step in the understanding of the genetic processes that govern marsupial immunity, and also allow us to begin to trace the evolution of the mammalian immune system.
10. The thymus reconstituted nude rat
DEFF Research Database (Denmark)
Hougen, H P; Klausen, B
1987-01-01
The monoclonal antibodies OX6, OX19, W3/13, OX7, OX8, and W3/25 were used to gain information about the distribution of different lymphocyte subpopulations in peripheral lymphoid organs of neonatally isogeneic and allogeneic thymus reconstituted nude rats. Splenic mitogen responsiveness, xenogeneic...... cell response is far better following isografting. We, therefore, conclude that isogeneic thymus grafting is an easy method of reconstituting the nude rat immunologically....
11. T-Cell Reconstitution after Thymus Xenotransplantation Induces Hair Depigmentation and Loss
OpenAIRE
Furmanski, A. L.; O Shaughnessy, R. F.; Saldana, J. I.; Blundell, M. P.; Thrasher, A. J.; Sebire, N J; Davies, E G; Crompton, T.
2013-01-01
Here we present a mouse model for T-cell targeting of hair follicles, linking the pathogenesis of alopecia to that of depigmentation disorders. Clinically, thymus transplantation has been successfully used to treat T-cell immunodeficiency in congenital athymia, but is associated with autoimmunity. We established a mouse model of thymus transplantation by subcutaneously implanting human thymus tissue into athymic C57BL/6 nude mice. These xenografts supported mouse T-cell development. Surprisin...
12. The mystery of the thymus gland.
Science.gov (United States)
Liu, Daniel; Ellis, Harold
2016-09-01
The thymus is the last organ in the human body to have its mechanisms fully understood, having had its function fully delineated more than 50 years ago (Miller , Tissue Antigens 63:509-517). Prior to this, the thymus gland has had an interesting history with theories having included a role in fetal growth and development before becoming more sinisterly, a cause of sudden infant death in the late 19th century known as status lymphaticus (Paltauf , Wien Klin Wochenschr 2:877-881). Until Miller (, Lancet 278:748-749) eventually proved its primarily immunological role, the history of this mysterious gland has closely mirrored the history of medicine itself, troubling the minds of pathologists such as Virchow (, Ueber die Chlorose und die damit zusammenhängenden Anomalien im Gefässapparate, insbesondere über "Endocarditis puerperalis," vorgetragen in der Sitzung der Berliner Geburtshülflichen Gesellschaft vom 12) and Grawitz (, Deut Med Wochenschr 22:429-431), surgeons such as Astley Cooper (, The Anatomy of the Thymus Gland) and Keynes (1953, Ann R Coll Surg 12:88), and eminent medical epidemiologists such as Greenwood and Woods [, J Hyg (Lond) 26:305-326]. This article will hopefully be of interest therefore to both clinician and historian alike. Clin. Anat. 29:679-684, 2016. © 2016 Wiley Periodicals, Inc. PMID:27037529
13. Chemical composition of essential oils of Thymus and Mentha species and their antifungal activities.
NARCIS (Netherlands)
Sokovic, M.D.; Vukojevic, J.; Marin, P.D.; Brkic, D.D.; Vajs, V.; Griensven, van L.J.L.D.
2009-01-01
The potential antifungal effects of Thymus vulgaris L., Thymus tosevii L., Mentha spicata L., and Mentha piperita L. (Labiatae) essential oils and their components against 17 micromycetal food poisoning, plant, animal and human pathogens are presented. The essential oils were obtained by hydrodestil
International Nuclear Information System (INIS)
The purpose of this study was to determine the radiosensitivity and repair kinetics of adult human parenchymal hepatocytes. Discarded viable human liver was obtained from the surgical pathology laboratory, and the cells were enzymatically isolated via a modification of the 2-step in situ collagenase perfusion technique used for the rat. The isolated hepatocytes were cultured with MEM media (10% FCS) in collagen coated 60 mm plates. Three hr after the cells were placed in culture, the media was changed to remove any dead unattached hepatocytes. After 24hr the viable hepatocytes were removed from the plates with collagenase and irradiated (40C, 21% O/sub 2/) with /sup 60/Co (1 Gy/min). The alkaline elution technique was used to quantify the single strand breaks (SSB). A linear dose response curve was obtained when the strand scission factor was plotted versus radiation dose and the slopes for the rat (4 cases) and human hepatocytes (6 cases) were 0.0302 and 0.0221 Gy/sup -1/, respectively. Thus, human hepatocytes are approximately 25% more radioresistant than those from the rat; this correlates with the GSH levels in the human hepatocytes (15 mM) being 20% greater than that in rat hepatocytes (12 mM). In contrast, the kinetics of repair of SSB in human hepatocytes was t/sub 1/2 fast/ = 20 min. t/sub 1/2 slow/ = 267 min) approximately 3 times slower than that in rat hepatocytes (t/sub 1/2 fast/ = 6 min, t/sub 1/2 slow/ = 98 min) and after 3 hr of repair the percent of the initial damage remaining was 20% and 15%, respectively. These date imply that in comparison to rat hepatocytes, human hepatocytes would be more radioresistant to large single doses, but equal if not more sensitive to fractionated radiation treatment
15. A unified theory of central tolerance in the thymus.
Science.gov (United States)
Liu, Yong-Jun
2006-05-01
Non-deletional tolerance resulting in the generation of regulatory T cells within the thymus is a key mechanism for the establishment of immunological self-tolerance. How the high-affinity self-reactive regulatory T cells escape negative selection and what type of antigen-presenting cells positively select them within the thymus are unsolved questions. Previous studies suggest that thymic epithelial cells are crucial for the positive selection of regulatory T cells in thymus. A recent study from my group shows that a subset of dendritic cells (that have been "educated" by the thymic stromal lymphopoietin molecule produced by a thymic cell type known as Hassall's corpuscles) positively select regulatory T cells within the medulla of human thymus. Here, I discuss the implications and historical context of this new result and suggest that a subset of mature dendritic cells within the thymic medulla protects the medium- to high-affinity self-reactive T cells from negative deletion and induces their differentiation into regulatory T cells in the thymus. PMID:16580260
16. Cell pattern in adult human corneal endothelium.
Directory of Open Access Journals (Sweden)
Carlos H Wörner
Full Text Available A review of the current data on the cell density of normal adult human endothelial cells was carried out in order to establish some common parameters appearing in the different considered populations. From the analysis of cell growth patterns, it is inferred that the cell aging rate is similar for each of the different considered populations. Also, the morphology, the cell distribution and the tendency to hexagonallity are studied. The results are consistent with the hypothesis that this phenomenon is analogous with cell behavior in other structures such as dry foams and grains in polycrystalline materials. Therefore, its driving force may be controlled by the surface tension and the mobility of the boundaries.
17. VEGF-mediated cross-talk within the neonatal murine thymus
OpenAIRE
Cuddihy, Andrew R.; Ge, Shundi; Zhu, Judy; Jang, Julie; Chidgey, Ann; Thurston, Gavin; Boyd, Richard; Crooks, Gay M.
2009-01-01
Although the mechanisms of cross-talk that regulate the hematopoietic and epithelial compartments of the thymus are well established, the interactions of these compartments with the thymic endothelium have been largely ignored. Current understanding of the thymic vasculature is based on studies of adult thymus. We show that the neonatal period represents a unique phase of thymic growth and differentiation, marked by endothelium that is organized as primitive, dense networks of capillaries dep...
18. Have you got any cholesterol? Adults' views of human nutrition
Science.gov (United States)
Schibeci, Renato; Wong, Khoon Yoong
1994-12-01
The general aim of our human nutrition project is to develop a health education model grounded in ‘everyday’ or ‘situated’ cognition (Hennessey, 1993). In 1993, we began pilot work to document adult understanding of human nutrition. We used a HyperCard stack as the basis for a series of interviews with 50 adults (25 university students, and 25 adults from offcampus). The interviews were transcribed and analysed using the NUDIST computer program. A summary of the views of these 50 adults on selected aspects of human nutrition is presented in this paper.
19. Human Adult Olfactory Bulb Neurogenesis? Novelty Is the Best Policy
OpenAIRE
Macklis, Jeffrey Daniel
2012-01-01
There is ongoing controversy as to whether the understanding of adult mammalian neurogenesis gained from rodent studies is applicable to humans. In this issue of Neuron, Bergmann et al. (2012) propose that adult human olfactory bulb neurogenesis with long-term neuronal survival is extremely limited.
20. Adult Education & Human Resource Development: Overlapping and Disparate Fields
Science.gov (United States)
Watkins, Karen E.; Marsick, Victoria J.
2014-01-01
Adult education and human resource development as fields of practice and study share some roots in common but have grown in different directions in their histories. Adult education's roots focused initially on citizenship for a democratic society, whereas human resource development's roots are in performance at work. While they have…
1. Phenotypic characterization of early events of thymus repopulation in radiation bone marrow chimeras
International Nuclear Information System (INIS)
2. Regeneration of rat thymus after irradiation
International Nuclear Information System (INIS)
The regeneration processes were investigated in the rat thymus after heavy dose irradiation (6 and 8 Gy). The weight of thymus was gradually recovered to normal level in 6 Gy irradiated thymus, however it recovered only up to 65% of normal level in 8 Gy irradiated thymus. The ED2 positive macrophages were increased on day 3, and then gradually decreased to normal level in 6 Gy irradiated thymus. Inflammatory cytokines (IL-1β, IFN-γ and TNF-α) mRNA expressions were gradually recovered from day 7, however IL-6 mRNA was expressed transiently on day 7 after 8 Gy irradiation. These observations suggest that regeneration processes of irradiated thymus may be intimately regulated by cytokine networks. (author)
3. Thymus vulgaris subsp. mansanetianus subsp. nov. (Lamiaceae)
OpenAIRE
Pedro Pablo Ferrer-Gallego; Albert J. Navarro Peris; Emilio Laguna Lumbreras; Gonzalo Mateo Sanz
2013-01-01
RESUMEN: Se describe una nueva subespecie de Thymus vulgaris L. (Lamiaceae); Th. vulgaris subsp. mansanetianus subsp. nov., caracterizada por presentar un hábito postrado, tallos estoloníferos, decumbentes y radicantes, hojas muy estrechas y una floración otoñal. ABSTRACT: Thymus vulgaris subsp. mansanetianus subsp. nov. (Lamiaceae). A new subspecies of Thymus vulgaris L. (Lamiaceae); Th. vulgaris subsp. mansanetianus subsp. nov. is described. This new subspecies is characterized by its prost...
4. Adult Human Neurogenesis: from Microscopy to Magnetic Resonance Imaging
Directory of Open Access Journals (Sweden)
AmandaSierra
2011-04-01
Full Text Available Neural stem cells reside in well-defined areas of the adult human brain and are capable of gene-rating new neurons throughout the life span. In rodents, it is well established that the new born neurons are involved in olfaction as well as in certain forms of memory and learning. In humans, the functional relevance of adult human neurogenesis is being investigated, in particular its implication in the etiopathology of a variety of brain disorders. Adult neurogenesis in the human brain was discovered by utilizing methodologies directly imported from the rodent research, such as immunohistological detection of proliferation and cell-type specific biomarkers in postmortem or biopsy tissue. However, in the vast majority of cases, these methods do not support longitudinal studies; thus, the capacity of the putative stem cells to form new neurons under different disease conditions cannot be tested. More recently, new technologies have been specifically developed for the detection and quantification of neural stem cells in the living human brain. These technologies rely on the use of magnetic resonance imaging, available in hospitals worldwide. Although they require further validation in rodents and primates, these new methods hold the potential to test the contribution of adult human neurogenesis to brain function in both health and disease. This review reports on the current knowledge on adult human neurogenesis. We first review the different methods available to assess human neurogenesis, both ex vivo and in vivo and then appraise the changes of adult neurogenesis in human diseases.
5. CT findings of the thymus
Energy Technology Data Exchange (ETDEWEB)
Kang, Eun Young; Kim, Yun Hwan; Seol, Hae Young; Chung, Woun Kyun; Suh, Won Hyuck [Korea University College of Medicine, Seoul (Korea, Republic of)
1987-02-15
In 14 cases of normal and abnormal thymus proved surgically and histopathologically in korea University Hae Wha Hospital during recent 6 years, the clinical and CT findings were analyzed. 1. Of 14 cases, 2 cases were normal thymus, 5 cases were thymic hyperplasia, 4 cases were benign thymoma, 2 case were malignant thymoma and 1 case was thymic cyst. 2. Of 14 cases, 10 cases were associated with myasthenia gravis, and 7 of these 10 cases were 3rd to 5th decades females. Among 10 cases with myasthenia gravis. 5 cases were thymic hyperplasia, 1 case was benign thymoma, 2 cases were malignant thymoma, and 2 cases were normal thymus. 3. All 5 thymic hyperplasia were associated with myasthenia gravis. CT findings of thymic hyperplasia were normal in 4 cases and increased lobe thickness in 1 case. 4. Of 4 cases of benign thymoma, only 1 case was associated with myasthenia gravis, and all 4 cases were positive findings in CT scan. CT findings of benign thymoma were round or oval soft tissue mass in anterior mediastinum, and 1 case had punctuate calcifications. 5. Of 2 cases of malignant thymoma, all 2 cases were associated with myasthenia gravis and positive findings in CT scan. CT findings of malignant thymoma were anterior mediastinal soft tissue mass with obliteration of the normal fat planes surrounding great vessels. SVC compression, and pleural tumor implants. 6. CT yielded significant diagnostic information of differential diagnosis between thymoma and thymoma hyperplasia in myasthenia gravis patients. Also CT was highly sensitive test in detection of thymoma and determined the extent and invasiveness of thymoma.
6. CT findings of the thymus
International Nuclear Information System (INIS)
In 14 cases of normal and abnormal thymus proved surgically and histopathologically in korea University Hae Wha Hospital during recent 6 years, the clinical and CT findings were analyzed. 1. Of 14 cases, 2 cases were normal thymus, 5 cases were thymic hyperplasia, 4 cases were benign thymoma, 2 case were malignant thymoma and 1 case was thymic cyst. 2. Of 14 cases, 10 cases were associated with myasthenia gravis, and 7 of these 10 cases were 3rd to 5th decades females. Among 10 cases with myasthenia gravis. 5 cases were thymic hyperplasia, 1 case was benign thymoma, 2 cases were malignant thymoma, and 2 cases were normal thymus. 3. All 5 thymic hyperplasia were associated with myasthenia gravis. CT findings of thymic hyperplasia were normal in 4 cases and increased lobe thickness in 1 case. 4. Of 4 cases of benign thymoma, only 1 case was associated with myasthenia gravis, and all 4 cases were positive findings in CT scan. CT findings of benign thymoma were round or oval soft tissue mass in anterior mediastinum, and 1 case had punctuate calcifications. 5. Of 2 cases of malignant thymoma, all 2 cases were associated with myasthenia gravis and positive findings in CT scan. CT findings of malignant thymoma were anterior mediastinal soft tissue mass with obliteration of the normal fat planes surrounding great vessels. SVC compression, and pleural tumor implants. 6. CT yielded significant diagnostic information of differential diagnosis between thymoma and thymoma hyperplasia in myasthenia gravis patients. Also CT was highly sensitive test in detection of thymoma and determined the extent and invasiveness of thymoma.
7. Adult Literacy Education and Human Rights: A View from Afghanistan
Science.gov (United States)
Andersen, Susan M.; Kooij, Christina S.
2007-01-01
In this article, we argue that adult literacy as part of international development is an issue of both human rights and women's rights. We explore this by presenting a case study of the effects of one innovative adult literacy program in Afghanistan that places men and women, as well as various ethnicities, together in the same classroom as…
8. Thymus
Science.gov (United States)
... Thyroid & Parathyroid Glands Adrenal Gland Pancreas Gonads Other Endocrine Glands Review Quiz Cardiovascular System Heart Structure of the Heart Physiology of the Heart Blood Classification & Structure of Blood ...
9. Dopaminerge Differenzierung adulter humaner hippocampaler Stammzellen
OpenAIRE
Türk, Matthias
2013-01-01
Hintergrund und Ziele: Nachdem seit der ersten Hälfte des letzten Jahrhunderts durch mehrere Experimente adulte Neurogenese schließlich nachgewiesen und somit Cajals Dogma widerlegt werden konnte, erlebten die Neurowissenschaften durch die Möglichkeit zur Isolation adulter neuraler Stammzellen ein exponentielles Wachstum. Gleichzeitig mit der basiswissenschaftlichen Aufarbeitung der adulten Neurogenese sowohl im Tier, als auch im Menschen, kam die Idee der therapeutischen Verwendung dieser, v...
10. Bacteriology of moderate (chronic) periodontitis in mature adult humans.
OpenAIRE
Moore, W E; Holdeman, L V; Cato, E P; Smibert, R M; Burmeister, J A; Ranney, R R
1983-01-01
A total of 171 taxa was represented among 1,900 bacterial isolates from 60 samples of sites affected with moderate periodontitis in 22 mature adult humans. The composition of the subgingival sulcus flora was statistically significantly different from that of the adjacent supragingival flora and the subgingival flora of 14 people with healthy gingiva, but was not significantly different from that of sulci affected with severe periodontitis in 21 young human adults. The sulcus floras of moderat...
11. Editorial: Technology for higher education, adult learning and human performance
OpenAIRE
Minhong Wang; Chi-Cheng Chang; Feng Wu
2013-01-01
This special issue is dedicated to technology-enabled approaches for improving higher education, adult learning, and human performance. Improvement of learning and human development for sustainable development has been recognized as a key strategy for individuals, institutions, and organizations to strengthen their competitive advantages. It becomes crucial to help adult learners and knowledge workers to improve their self-directed and life-long learning capabilities. Meanwhile, advances in t...
12. Chemical Composition of Essential Oilsof Thymus and Mentha Speciesand Their Antifungal Activities
OpenAIRE
Van Griensven, Leo J. L. D.; Vlatka Vajs; Dejan D. Brkić; Petar D. Marin; Jelena Vukojević; Marina D. Soković
2009-01-01
The potential antifungal effects of Thymus vulgaris L., Thymus tosevii L., Mentha spicata L., and Mentha piperita L. (Labiatae) essential oils and their components against 17 micromycetal food poisoning, plant, animal and human pathogens are presented. The essential oils were obtained by hydrodestillation of dried plant material. Their composition was determined by GC-MS. Identification of individual constituents was made by comparison with analytical standards, and by computer matching mass ...
13. Chemical composition, antitumor and antimicrobial activity of Thymus vulgaris and T. algeriensis essential oils
OpenAIRE
Nikolic, Milos; Glamočlija, Jasmina; Ćirić, Ana; Ferreira, Isabel C.F.R.; Ricardo C. Calhelha; Perić, Tamara; Marković, Dejan; Giweli, Abdulhamed; Soković, Marina
2013-01-01
Plants from genus Thymus are often used in traditional medicine. Some of these species are important medicinal plants that are used in ethnomedicine. In this work, analysis of phytochemicals and bioactivity evaluation of Thymus vulgaris and T. algericnsis essential oils were done. The chemical composition of oils were evaluated using GC/MS; cytotoxic activity was tested against five human tumor cell lines MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), ...
14. Chemical composition of essential oils of Thymus and Mentha species and their antifungal activities.
OpenAIRE
Sokovic,, M.D.; Vukojevic,, J.; Marin, P.D.; Brkic, D.D.; Vajs, V.; Griensven, van, L.J.L.D.
2009-01-01
The potential antifungal effects of Thymus vulgaris L., Thymus tosevii L., Mentha spicata L., and Mentha piperita L. (Labiatae) essential oils and their components against 17 micromycetal food poisoning, plant, animal and human pathogens are presented. The essential oils were obtained by hydrodestillation of dried plant material. Their composition was determined by GC-MS. Identification of individual constituents was made by comparison with analytical standards, and by computer matching mass ...
15. Effects of Thyme Extract Oils (from Thymus vulgaris, Thymus zygis, and Thymus hyemalis on Cytokine Production and Gene Expression of oxLDL-Stimulated THP-1-Macrophages
Directory of Open Access Journals (Sweden)
A. Ocaña
2012-01-01
Full Text Available Properties of thyme extracts from three different species (Thymus vulgaris, Thymus zygis, and Thymus hyemalis were examined. Two oil fractions from each species were obtained by CO2 supercritical fluid extraction. Main compounds presented in the supercritical extracts of the three thyme varieties were 1,8 cineole, thymol, camphor, borneol, and carvacrol. As a cellular model of inflammation/atherogenesis, we use human macrophages derived from THP-1 monocytes and activated by oxidized LDLs. These cells were incubated with the thyme fraction oils, and the productions and gene expressions of the inflammatory mediators TNF-α, IL-1B, IL-6, and IL-10 were determined. Thyme extracts significantly reduced production and gene expression of the proinflammatory mediators TNF-α, IL-1B, and IL-6 and highly increased these parameters on the anti-inflammatory IL-10 cytokine. Changes on production and gene expressions were dose dependent and according to the thyme content of each species. Taken together, these results may suggest that thyme extracts could have anti-inflammatory effects.
16. Thymus: the next (re)generation.
Science.gov (United States)
Chaudhry, Mohammed S; Velardi, Enrico; Dudakov, Jarrod A; van den Brink, Marcel R M
2016-05-01
As the primary site of T-cell development, the thymus plays a key role in the generation of a strong yet self-tolerant adaptive immune response, essential in the face of the potential threat from pathogens or neoplasia. As the importance of the role of the thymus has grown, so too has the understanding that it is extremely sensitive to both acute and chronic injury. The thymus undergoes rapid degeneration following a range of toxic insults, and also involutes as part of the aging process, albeit at a faster rate than many other tissues. The thymus is, however, capable of regenerating, restoring its function to a degree. Potential mechanisms for this endogenous thymic regeneration include keratinocyte growth factor (KGF) signaling, and a more recently described pathway in which innate lymphoid cells produce interleukin-22 (IL-22) in response to loss of double positive thymocytes and upregulation of IL-23 by dendritic cells. Endogenous repair is unable to fully restore the thymus, particularly in the aged population, and this paves the way toward the need for exogenous strategies to help regenerate or even replace thymic function. Therapies currently in clinical trials include KGF, use of the cytokines IL-7 and IL-22, and hormonal modulation including growth hormone administration and sex steroid inhibition. Further novel strategies are emerging in the preclinical setting, including the use of precursor T cells and thymus bioengineering. The use of such strategies offers hope that for many patients, the next regeneration of their thymus is a step closer. PMID:27088907
17. Functionally active T cells land T cell precursors in the thymus of newborn mice irradiated in fetal stage of development
International Nuclear Information System (INIS)
Mice were irradiated in dose of 2 Gy in 14 or 17 days of gestation. Irradiation retarded the increase of cell number in developing thymuses but in the day of birth the number of thymocytes was normalized. In normal development SC-1+ cells (T cell precursors) disappeared from the thymus immediately before the birth. After the irradiation they persisted in the newborn thymus. Mitogenic responses of newborn thymocytes on the action of thymic peptides and T cell mitogens were decreased after the fetal irradiation (adult irradiation enhances mitogenic response of thymocytes)
18. Restriction specificity of virus-specific cytotoxic T cells from thymectomised irradiated bone marrow chimeras reconstituted with thymus grafts
International Nuclear Information System (INIS)
Adult-thymectomised lethally irradiated mice A that were reconstituted with T-cell-depleted bone marrow cells of (A X B)F1 origin plus fetal thymus grafts of (B X C)F1 origin generated virus-specific T cells restricted to B alone; adult-thymectomised and lethally irradiated (A X B)F1 mice that were reconstituted with T-cell depleted bone marrow cells of (A X B)F1 origin plus fetal thymus grafts of A and of B origin generated virus-specific T cells restricted to A or to B. These results do not reveal obvious suppressive influences of host or stem-cell origin that might have explained results obtained with various irradiated bone marrow or thymus chimeras, they indicate that the thymus' influence on maturing T cells is one of the limiting steps in the selection of T cells' restriction specificities. (Auth.)
19. Expression of the cystic fibrosis gene in adult human lung.
OpenAIRE
Engelhardt, J F; Zepeda, M; Cohn, J.A.; Yankaskas, J R; Wilson, J. M.
1994-01-01
Critical to an understanding of the pulmonary disease in cystic fibrosis (CF) and the development of effective gene therapies is a definition of the distribution and regulation of CF gene expression in adult human lung. Previous studies have detected the product of the CF gene, the CF transmembrane conductance regulator (CFTR), in submucosal glands of human bronchi. In this report, we have characterized the distribution of CFTR RNA and protein in the distal airway and alveoli of human lungs. ...
20. Review on Adult Neurogenesis in Humans and Other Mammals
OpenAIRE
Tesfamichael Berhe
2015-01-01
Research in the field of adult neurogenesis has recently indicated significant progress.The objective of this paper is to review the basic concepts, new findings and clinical implications of neurogenesis making emphasis on the significance, especially in humans. Although scientists still debate the extent and purpose of neurogenesis in the adult brain, research has identified certain areas of the brain where it is most evident. These areas include the hippocampus, caudate nucleus, and olfacto...
1. Adult human metapneumonovirus (hMPV) pneumonia mimicking Legionnaire's disease.
Science.gov (United States)
2016-01-01
In adults hospitalized with viral pneumonias the main differential diagnostic consideration is influenza pneumonia. The respiratory viruses causing viral influenza like illnesses (ILIs), e.g., RSV may closely resemble influenza. Rarely, extrapulmonary findings of some ILIs may resemble Legionnaire's disease (LD), e.g., adenovirus, human parainfluenza virus (HPIV-3). We present a most unusual case of human metapneumonovirus pneumonia (hMPV) with some characteristic extrapulmonary findings characteristic of LD, e.g., relative bradycardia, as well as mildly elevated serum transaminases and hyphosphatemia. We believe this is the first reported case of hMPV pneumonia in a hospitalized adult that had some features of LD. PMID:26988110
2. CT evaluation of thymus in myasthenia gravis
International Nuclear Information System (INIS)
The relationship between myasthenia gravis and the thymus was well establish and myasthenia gravis occurs in the presence of thymic hyperplasia or thymoma or occasionally in histologically normal thymus. Since not every patients with myasthenia gravis is a candidate for thymectomy, unless a thymoma is present, the differentiation of normal and hyperplastic thymus from thymoma becomes important. Authors reviewed retrospectively clinical records and chest CT scans of 18 patients with myasthenia gravis who underwent thymectomy during recent 5 years, to evaluate the role of CT scan. The results were as follows. 1 Of total 18 cases, 5 cases had normal thymus, 6 cases had thymic hyperplasia, 4 cases had benign thymoma and 3 cases had malignant thymoma. 2. Of 5 cases of normal thymus, no false positive cases were noted in CT scan. 3. Of 6 cases of thymic hyperplasia, CT findings were normal except 1 cases of thickened left thymic lobe. 4. Of 7 cases of thymoma, no false negative cases were noted in CT scan. 5. CT findings of benign thymoma were round or oval shaped, discrete, slightly enhancing soft tissue mass in anterior mediastinum. 6. CT findings of malignant thymoma were lobulated contoured, infiltrative, soft tissue mass lesion in anterior mediastinum with calcifications, pleural tumor implants, and SVC compression. CT yielded valuable information on differential diagnosis of thymoma, thymic hyperplasia and normal thymus. Also CT was a highly sensitive method in the detection of thymoma and determining the extent and invasiveness
3. CT evaluation of thymus in myasthenia gravis
Energy Technology Data Exchange (ETDEWEB)
Kim, Guk Hee [Insung Hospital, Chuncheon (Korea, Republic of); Kang, Eun Young; Lee, Nam Joon; Suh, Won Hyuck [Korea University College of Medicine, Seoul (Korea, Republic of)
1989-12-15
The relationship between myasthenia gravis and the thymus was well establish and myasthenia gravis occurs in the presence of thymic hyperplasia or thymoma or occasionally in histologically normal thymus. Since not every patients with myasthenia gravis is a candidate for thymectomy, unless a thymoma is present, the differentiation of normal and hyperplastic thymus from thymoma becomes important. Authors reviewed retrospectively clinical records and chest CT scans of 18 patients with myasthenia gravis who underwent thymectomy during recent 5 years, to evaluate the role of CT scan. The results were as follows. 1 Of total 18 cases, 5 cases had normal thymus, 6 cases had thymic hyperplasia, 4 cases had benign thymoma and 3 cases had malignant thymoma. 2. Of 5 cases of normal thymus, no false positive cases were noted in CT scan. 3. Of 6 cases of thymic hyperplasia, CT findings were normal except 1 cases of thickened left thymic lobe. 4. Of 7 cases of thymoma, no false negative cases were noted in CT scan. 5. CT findings of benign thymoma were round or oval shaped, discrete, slightly enhancing soft tissue mass in anterior mediastinum. 6. CT findings of malignant thymoma were lobulated contoured, infiltrative, soft tissue mass lesion in anterior mediastinum with calcifications, pleural tumor implants, and SVC compression. CT yielded valuable information on differential diagnosis of thymoma, thymic hyperplasia and normal thymus. Also CT was a highly sensitive method in the detection of thymoma and determining the extent and invasiveness.
4. Clonally Expanding Thymocytes Having Lineage Capability in Gamma-Ray-Induced Mouse Atrophic Thymus
International Nuclear Information System (INIS)
Purpose: To characterize, in the setting of γ-ray-induced atrophic thymus, probable prelymphoma cells showing clonal growth and changes in signaling, including DNA damage checkpoint. Methods and Materials: A total of 111 and 45 mouse atrophic thymuses at 40 and 80 days, respectively, after γ-irradiation were analyzed with polymerase chain reaction for D-J rearrangements at the TCRβ locus, flow cytometry for cell cycle, and Western blotting for the activation of DNA damage checkpoints. Results: Limited D-J rearrangement patterns distinct from normal thymus were detected at high frequencies (43 of 111 for 40-day thymus and 21 of 45 for 80-day thymus). Those clonally expanded thymocytes mostly consisted of CD4+CD8+ double-positive cells, indicating the retention of lineage capability. They exhibited pausing at a late G1 phase of cell cycle progression but did not show the activation of DNA damage checkpoints such as γH2AX, Chk1/2, or p53. Of interest is that 17 of the 52 thymuses showing normal D-J rearrangement patterns at 40 days after irradiation showed allelic loss at the Bcl11b tumor suppressor locus, also indicating clonal expansion. Conclusion: The thymocytes of clonal growth detected resemble human chronic myeloid leukemia in possessing self-renewal and lineage capability, and therefore they can be a candidate of the lymphoma-initiating cells.
5. The weight of nations: an estimation of adult human biomass
Directory of Open Access Journals (Sweden)
Walpole Sarah
2012-06-01
Full Text Available Abstract Background The energy requirement of species at each trophic level in an ecological pyramid is a function of the number of organisms and their average mass. Regarding human populations, although considerable attention is given to estimating the number of people, much less is given to estimating average mass, despite evidence that average body mass is increasing. We estimate global human biomass, its distribution by region and the proportion of biomass due to overweight and obesity. Methods For each country we used data on body mass index (BMI and height distribution to estimate average adult body mass. We calculated total biomass as the product of population size and average body mass. We estimated the percentage of the population that is overweight (BMI > 25 and obese (BMI > 30 and the biomass due to overweight and obesity. Results In 2005, global adult human biomass was approximately 287 million tonnes, of which 15 million tonnes were due to overweight (BMI > 25, a mass equivalent to that of 242 million people of average body mass (5% of global human biomass. Biomass due to obesity was 3.5 million tonnes, the mass equivalent of 56 million people of average body mass (1.2% of human biomass. North America has 6% of the world population but 34% of biomass due to obesity. Asia has 61% of the world population but 13% of biomass due to obesity. One tonne of human biomass corresponds to approximately 12 adults in North America and 17 adults in Asia. If all countries had the BMI distribution of the USA, the increase in human biomass of 58 million tonnes would be equivalent in mass to an extra 935 million people of average body mass, and have energy requirements equivalent to that of 473 million adults. Conclusions Increasing population fatness could have the same implications for world food energy demands as an extra half a billion people living on the earth.
6. Two adult human voxel phantoms based on polygon mesh surfaces
International Nuclear Information System (INIS)
Among computational models used in radiation protection, voxel phantoms based on computer tomographic (CT), nuclear magnetic resonance (NMR) or colour photographic images, became very popular in recent years. Although being a true to nature representation of the scanned individual the scanning is usually made in supine position, which causes a shift of internal organs towards the ribcage, a compression of the lungs and a reduction of the sagittal diameter especially in the abdominal region compared to the anatomy of a person in upright standing position, which in turn can influence absorbed or equivalent dose estimates. This study proposes a method for human phantom design using tools recently developed in the areas of computer graphics and animated films and applies them to the creation and modeling of artificial 3D human organs and tissues. Two models, a male and a female adult human phantom have been developed based on anatomical atlases, observing at the same time the anatomical specifications published by the International Commission on Radiological Protection for the male and female reference adult. The phantoms are called FAXAA (Female Adult voXelAverage-Average) and MAXAA (Male Adult voXelAverage-Average) because they represent female and male adults with average weight and average height. (author)
7. An anatomically comprehensive atlas of the adult human brain transcriptome
NARCIS (Netherlands)
Hawrylycz, M.J.; Beckmann, C.F.; et al., et al.
2012-01-01
Neuroanatomically precise, genome-wide maps of transcript distributions are critical resources to complement genomic sequence data and to correlate functional and genetic brain architecture. Here we describe the generation and analysis of a transcriptional atlas of the adult human brain, comprising
8. Telocytes of the human adult trigeminal ganglion.
Science.gov (United States)
Rusu, Mugurel Constantin; Cretoiu, Dragos; Vrapciu, Alexandra Diana; Hostiuc, Sorin; Dermengiu, Dan; Manoiu, Vasile Sorin; Cretoiu, Sanda Maria; Mirancea, Nicolae
2016-06-01
Telocytes (TCs) are typically defined as cells with telopodes by their ultrastructural features. Their presence was reported in various organs, however little is known about their presence in human trigeminal ganglion. To address this issue, samples of trigeminal ganglia were tested by immunocytochemistry for CD34 and examined by transmission electron microscopy (TEM). We found that TCs are CD34 positive and form networks within the ganglion in close vicinity to microvessels and nerve fibers around the neuronal-glial units (NGUs). TEM examination confirmed the existence of spindle-shaped and bipolar TCs with one or two telopodes measuring between 15 to 53 μm. We propose that TCs are cells with stemness capacity which might contribute in regeneration and repair processes by: modulation of the stem cell activity or by acting as progenitors of other cells present in the normal tissue. In addition, further studies are needed to establish if they might influence the neuronal circuits. PMID:27147447
9. Studies on rat thymus. III. Phosphorylation
Energy Technology Data Exchange (ETDEWEB)
Thomson, J.F.; Carttar, M.S.; Neff, J.B.
1950-12-31
Because of the rapid decrease in concentration of ribonucleic acid (RNA) and desoxyribonucleic acid (DNA) in the thymus of rats following gamma irradiation from a Co{sup 60} source, it was of interest to further investigate this phenomenon. As a first consideration, we have studied the capacity of thymus homogenates to esterify inorganic phosphate, an imperative step in endergonic processes, such as nucleic acid synthesis, the energy for which is provided by high-energy phosphate bonds maintained by catabolic processes. Three hours after exposure to 800 r, the thymuses of irradiated rats showed a decreased capacity to esterify inorganic phosphate. This impairment of phosphorylation was not accompanied by a decreased rate of oxygen consumption. 9 refs., 2 tabs.
10. Effect of laser radiation on thymus hormones production
International Nuclear Information System (INIS)
Irradiation of the epithelial cells from human (cell line HTSC) by arsenid-gallium laser (0.89 nm, 1500 Hz) induces an enhancement of thymic hormone production. The concentration of α-1-thymosin was substantionally increased on the days 1 and 5 in culture after irradiation. The increase of thymulin level in cultural supernatants was less pronounced and displayed after irradiation during 3-4 minutes. Local laser irradiation of thymus region of rats (5 minutes, 10 times) induce the increase of serum concentration of α-1-thymosin and the decrease of serum level of thymulin 2 days after irradiation. 10 refs.; 2 figs
Science.gov (United States)
... after treatment for thymus cancer? What should you ask your doctor about thymus cancer? It’s important to ... your work schedule. Or you may want to ask about clinical trials for which you may qualify. ...
12. Editorial: Technology for higher education, adult learning and human performance
Directory of Open Access Journals (Sweden)
Minhong Wang
2013-09-01
Full Text Available This special issue is dedicated to technology-enabled approaches for improving higher education, adult learning, and human performance. Improvement of learning and human development for sustainable development has been recognized as a key strategy for individuals, institutions, and organizations to strengthen their competitive advantages. It becomes crucial to help adult learners and knowledge workers to improve their self-directed and life-long learning capabilities. Meanwhile, advances in technology have been increasingly enabling and facilitating learning and knowledge-related initiatives.. They have largely extended learning opportunities through the provision of resource-rich and learner-centered environment, computer-based learning support, and expanded social interactions and networks. Papers in this special issue are representative of ongoing research on integration of technology with learning for innovation and sustainable development in higher education institutions and organizational and community environments.
13. Chemical compositions of two different Thymus species essential oils
OpenAIRE
Samira Jaberi; Mahmoodreza Moein; Azizolah Jafari; Forough Karami
2015-01-01
Thymus is one of the most important members of Lamiaceae family. Aerial parts of the plant have been widely used in medicine. It has been reported that most of these effects are related to phenolic compounds especially thymol and carvacrol in Thymus essential oil. In this study, aerial parts of Thymus daenensis and Thymus lancifolius were collected from Kohgiluyeh and Boyer-Ahmad, Iran. Essential oils of aerial parts of these plants were gained by the hydrodistillation method and the chemical...
14. Neuropeptide Y in the Adult and Fetal Human Pineal Gland
OpenAIRE
Morten Møller; Pansiri Phansuwan-Pujito; Corin Badiu
2014-01-01
Neuropeptide Y was isolated from the porcine brain in 1982 and shown to be colocalized with noradrenaline in sympathetic nerve terminals. The peptide has been demonstrated to be present in sympathetic nerve fibers innervating the pineal gland in many mammalian species. In this investigation, we show by use of immunohistochemistry that neuropeptide Y is present in nerve fibers of the adult human pineal gland. The fibers are classical neuropeptidergic fibers endowed with large boutons en passag...
15. Thymus medulla under construction: Time and space oddities.
Science.gov (United States)
Alves, Nuno L; Ribeiro, Ana R
2016-04-01
The development of effective T-cell-based immunotherapies to treat infection, cancer, and autoimmunity should incorporate the ground rules that control differentiation of T cells in the thymus. Within the thymus, thymic epithelial cells (TECs) provide microenvironments supportive of the generation and selection of T cells that are responsive to pathogen-derived antigens, and yet tolerant to self-determinants. Defects in TEC differentiation cause syndromes that range from immunodeficiency to autoimmunity, which makes the study of TECs of fundamental and clinical importance to comprehend how immunity and tolerance are balanced. Critical to tolerance induction are medullary thymic epithelial cells (mTECs), which purge autoreactive T cells, or redirect them to a regulatory T-cell lineage. In this issue of the European Journal of Immunology, studies by Baik et al. and Mayer et al. [Eur. J. Immunol. 2016. 46: XXXX-XXXX and 46: XXXX-XXXX]) document novel spatial-temporal singularities in the lineage specification and maintenance of mTECs. While Baik et al. define a developmental checkpoint during mTEC specification in the embryo, Mayer et al. reveal that the generation and maintenance of the adult mTEC compartment is temporally controlled in vivo. The two reports described new developmentally related, but temporally distinct principles that underlie the homeostasis of the thymic medulla across life. PMID:26947141
16. Visualization of the thymus in myasthenia gravis
International Nuclear Information System (INIS)
We investigated whether CT had any advantage over pneumomediastinography (PMG) for the visualization of thymus in twenty-one patients with myasthenia gravis (MG). In two cases of thymoma which had been suspected with chest radiography, CT demonstrated an anterior mediastinal tumor distinguishable from other mediastinal organs, and for these cases PMG was not performed. Excluding three patients who were submitted to PMG only, CT of the anterior mediastinum was carried out in sixteen patients of MG, revealing thymic shadows in seven (44%). PMG followed by conventional tomography was done subsequently in three of these seven cases, for whom thymectomy was indicated because of uncontrollable myasthenic symptoms, and in all patients finger-like thymic shadows were disclosed. The vertical extension of thymus was more easily demonstrable by PMG than CT. PMG was carried out in six of nine patients in whom CT was negative, and in all cases thymic shadows were obvious with subsequent conventional tomography. Consequently, false negative rate of CT was at least 38% (6/16) with regard to the visualization of the nontumorous thymus. Although CT of the anterior mediastinum is useful as a screening method because of its non-invasiveness, its negative result does not rule out an absence of the pathologic thymus in view of its high false negative rate. In this regard, PMG is still necessary for the final determination of the thymic configuration in the MG patients. (J.P.N.)
17. Antifungal and antiaflatoxigenic potential of essential oils from an endemic Thymus fontanesii Boiss and Reut.
Directory of Open Access Journals (Sweden)
Zohra MOHAMMEDI
2010-01-01
Full Text Available Phytotherapy is based on the use of the plant products for the treatment of human, animal or vegetable diseases. With these aims, we studied the antifungal and antiaflatoxigenic effects of some aromatic plants. Essential oils were extracted by hydrodistillation using a Clevenger-type apparatus and tested against Aspergillus flavus. Thymus fontanesii, Ammoides verticillata and Mentha pulegium provided highest yield: 3.09%, 3.85%, and 3.25% respectively. The antifungal screening of these aromatic plants against Aspergillus flavus by direct contact method shows a high antifungal potential at Thymus fontanesii with a low amount of essential oil, which the CMI are 0.75µg/mL. This activity is characterized by a fungistatic action. The significant decrease in the production of aflatoxin B observed on CCM and reducing amount of AFB1 determined experimentally let hope for an antiaflatoxigenic effect linked to the use of Thymus fontanesii essential oil.
18. In vitro proliferation of adult human beta-cells.
Directory of Open Access Journals (Sweden)
Sabine Rutti
Full Text Available A decrease in functional beta-cell mass is a key feature of type 2 diabetes. Glucagon-like peptide 1 (GLP-1 analogues induce proliferation of rodent beta-cells. However, the proliferative capacity of human beta-cells and its modulation by GLP-1 analogues remain to be fully investigated. We therefore sought to quantify adult human beta-cell proliferation in vitro and whether this is affected by the GLP-1 analogue liraglutide.Human islets from 7 adult cadaveric organ donors were dispersed into single cells. Beta-cells were purified by FACS. Non-sorted cells and the beta-cell enriched ("beta-cells" population were plated on extracellular matrix from rat (804G and human bladder carcinoma cells (HTB9 or bovine corneal endothelial ECM (BCEC. Cells were maintained in culture+/-liraglutide for 4 days in the presence of BrdU.Rare human beta-cell proliferation could be observed either in the purified beta-cell population (0.051±0.020%; 22 beta-cells proliferating out of 84'283 beta-cells counted or in the non-sorted cell population (0.055±0.011%; 104 proliferating beta-cells out of 232'826 beta-cells counted, independently of the matrix or the culture conditions. Liraglutide increased human beta-cell proliferation on BCEC in the non-sorted cell population (0.082±0.034% proliferating beta-cells vs. 0.017±0.008% in control, p<0.05.These results indicate that adult human beta-cell proliferation can occur in vitro but remains an extremely rare event with these donors and particular culture conditions. Liraglutide increases beta-cell proliferation only in the non-sorted cell population and only on BCEC. However, it cannot be excluded that human beta-cells may proliferate to a greater extent in situ in response to natural stimuli.
19. Is the thymus a target organ in infectious diseases?
Directory of Open Access Journals (Sweden)
Wilson Savino
1992-01-01
Full Text Available The thymus is a central lymphoid organ, in wich T cell precursors differentiale and generate most of the so-called T cell reprtoire. Along with a variety of acute infectious diseases, we and others determined important changes in both microenvironmental and lymphoid compartments of the organ. For example, one major and common feature observed in acute viral, bacterial and parasitic diseases, is a depletion of cortical thymocytes, mostly those bearing the CD4-CD8 double positive phenotype. This occurs simmultaneously to the relative enrichment in medullary CD4 or CD8 single positive cells, expressing high densities of the CD3 complex. Additionally we noticed a variety of changes in the thymic microenvironment (and particularly is epithelial component, comprising abnormal location of thymic epithelial cell subsets as well has a denser Ia-bearing cellular network. Moreover, the extracellular matrix network was altered with an intralobular increase of basement membrane proteins that positively correlated with the degree of thymocyte death. Lastly, anti-thymic cell antibodies were detected in both human and animal models of infectious diseases, and in some of them a phenomenon of molecular mimicry could be evidenced. Taken together, the data receiwed herein clearly show that the thymus should be regarded as a target in infectious diseases.
20. Ontogeny of morningness-eveningness across the adult human lifespan
Science.gov (United States)
Randler, Christoph
2016-02-01
Sleep timing of humans can be classified alongside a continuum from early to late sleepers, with some people (larks) having an early activity, early bed, and rise times and others (owls) with a more nocturnally orientated activity. Only a few studies reported that morningness-eveningness changes significantly during the adult lifespan based on community samples. Here, I applied a different methodological approach to seek for evidence for the age-related changes in morningness-eveningness preferences by using a meta-data from all available studies. The new aspect of this cross-sectional approach is that only a few studies themselves address the age-related changes of the adult lifespan development, but that many studies are available that provide exactly the data needed. The studies came from 27 countries and included 36,939 participants. Age was highly significantly correlated with scores on the Composite Scale of Morningness ( r = 0.70). This relationship seems linear, because a linear regression explained nearly the same amount of variance compared to other models such as logarithmic, quadratic, or cubic models. The standard deviation of age correlated with the standard deviation of CSM scores ( r = 0.55), suggesting when there is much variance in age in a study; in turn, there is much variance in morningness. This meta-analytical approach shows that morningness-eveningness changes across the adult lifespan and that older age is related to higher morningness.
1. Ultrasonographic analysis of normal thymus in infants
International Nuclear Information System (INIS)
The purpose of this study is to analyse the ultrasonographic findings of normal thymus in infants and determine the pathologic findings. Forty two infants without a history of chronic disease, tumor or steroid therapy were scanned in the axial planes with a 7.0 MHz sector transducer. Bilaterality, homogeneity, and the shape and intensity of thymic echogenicity were analysed; shapes were classified as one of three types, namely bilobate, quandrangular or triangular. The intensities of thymic echogenicity were compared with those of the liver and spleen under the same conditions (time-gain compensation, depth and gain). The usual findings of normal thymus in infants are bilaterality and homogeneity, convex or shaight outer border, and echo intensity less than or equal to that of the liver and spleen. The possibility of thymic pathology is suggested when ultrasonography shows unilaterality, inhomogeneous echogenicity, and echogenicity greater than that of the liver and spleen. (author). 11 refs., 3 figs
2. Early reversal cells in adult human bone remodeling
DEFF Research Database (Denmark)
Abdelgawad, Mohamed Essameldin; Delaisse, Jean-Marie; Hinge, Maja;
2016-01-01
. Earlier preclinical studies indicate that reversal cells degrade the organic matrix left behind by the osteoclasts and that this degradation is crucial for the initiation of the subsequent bone formation. To our knowledge, this study is the first addressing these catabolic activities in adult human bone......The mechanism coupling bone resorption and formation is a burning question that remains incompletely answered through the current investigations on osteoclasts and osteoblasts. An attractive hypothesis is that the reversal cells are likely mediators of this coupling. Their nature is a big matter of...... debate. The present study performed on human cancellous bone is the first one combining in situ hybridization and immunohistochemistry to demonstrate their osteoblastic nature. It shows that the Runx2 and CD56 immunoreactive reversal cells appear to take up TRAcP released by neighboring osteoclasts...
3. Overview on mentha and thymus polyphenols
OpenAIRE
Olívia R. Pereira; Cardoso, Susana M.
2013-01-01
Mentha and Thymus are important genera of the Lamiaceae family widely distributed in the entire World and commonly used in traditional medicine. Indeed, many species of the two genera have been credited with a large list of health-benefit effects, including antioxidant, anti-inflammatory, antimicrobial, analgesic, neuroprotective and anticarcinogenic. In turn, these properties have been associated to the polyphenolic composition of the plants. The present review summarizes the phe...
4. Neuropeptide Y in the Adult and Fetal Human Pineal Gland
Directory of Open Access Journals (Sweden)
Morten Møller
2014-01-01
Full Text Available Neuropeptide Y was isolated from the porcine brain in 1982 and shown to be colocalized with noradrenaline in sympathetic nerve terminals. The peptide has been demonstrated to be present in sympathetic nerve fibers innervating the pineal gland in many mammalian species. In this investigation, we show by use of immunohistochemistry that neuropeptide Y is present in nerve fibers of the adult human pineal gland. The fibers are classical neuropeptidergic fibers endowed with large boutons en passage and primarily located in a perifollicular position with some fibers entering the pineal parenchyma inside the follicle. The distance from the immunoreactive terminals to the pinealocytes indicates a modulatory function of neuropeptide Y for pineal physiology. Some of the immunoreactive fibers might originate from neurons located in the brain and be a part of the central innervation of the pineal gland. In a series of human fetuses, neuropeptide Y-containing nerve fibers was present and could be detected as early as in the pineal of four- to five-month-old fetuses. This early innervation of the human pineal is different from most rodents, where the innervation starts postnatally.
5. Computed tomography of the thymus in myasthenia gravis
International Nuclear Information System (INIS)
Comparison of preoperative CT diagnosis and histopathological diagnosis for the thymus were studied in 39 patients with myasthenia gravis. The patients consisted of 10 patients with thymoma and 29 without thymoma confirmed at the operation. CT diagnosis was 11 thymomas, 18 thymic hyperplasias and 10 normal thymuses. Eleven thymomas revealed histopathologically 9 thymomas, one follicular lymphoid hyperplasia (FLH) and one involved thymus. Out of 18 thymic hyperplasias 15 cases were FLH and 3 involved thymus. There were 5 involved thymuses, 4 FLHs and one thymoma in the 10 normal thymuses on CT. The finding of 'reticular pattern', many small nodules scattered reticularly in the thymus, in computed tomography could be regarded as a sign suggesting FLH of the thymus. The accuracy of this finding of CT was 83% for FLH. The finding of thymoma on CT revealed 82% of the accuracy. Therefore, CT was very useful in the diagnosis of the localization of the thymoma but not for the diagnosis of FLH of the thymus. Nevertheless the finding of 'reticular pattern' on CT was helpful in the diagnosis of FLH. (author)
6. Computed tomography of the thymus in myasthenia gravis
Energy Technology Data Exchange (ETDEWEB)
Tanimura, Shigeo; Sakaguchi, Kozo; Tomoyasu, Hiroshi; Banba, Jiro; Masaki, Mikio; Kurosaki, Atsuko; Matsushita, Hisashi [Toranomon Hospital, Tokyo (Japan)
1995-01-01
Comparison of preoperative CT diagnosis and histopathological diagnosis for the thymus were studied in 39 patients with myasthenia gravis. The patients consisted of 10 patients with thymoma and 29 without thymoma confirmed at the operation. CT diagnosis was 11 thymomas, 18 thymic hyperplasias and 10 normal thymuses. Eleven thymomas revealed histopathologically 9 thymomas, one follicular lymphoid hyperplasia (FLH) and one involved thymus. Out of 18 thymic hyperplasias 15 cases were FLH and 3 involved thymus. There were 5 involved thymuses, 4 FLHs and one thymoma in the 10 normal thymuses on CT. The finding of reticular pattern, many small nodules scattered reticularly in the thymus, in computed tomography could be regarded as a sign suggesting FLH of the thymus. The accuracy of this finding of CT was 83% for FLH. The finding of thymoma on CT revealed 82% of the accuracy. Therefore, CT was very useful in the diagnosis of the localization of the thymoma but not for the diagnosis of FLH of the thymus. Nevertheless the finding of reticular pattern on CT was helpful in the diagnosis of FLH. (author).
7. Human behavioral momentum in a sample of older adults.
Science.gov (United States)
Plaud, J J; Plaud, D M; von Duvillard, S P
1999-04-01
Behavioral momentum, the persistence of behavior under altered environmental contingencies, is derived from Newtonian physics and operant psychology. It has relevance to behavior analysis in terms of shaping strong behaviors and ensuring effective relapse prevention strategies in behavior modification and therapy. The authors investigated whether changing the operant schedule contingencies affects the responses of older humans to different stimuli when reinforcement density is systematically manipulated. Fifteen older adults participated in a computer study in which each of 2 keys in a baseline condition was associated with the same schedule of reinforcement and multiple variable intervals; the only difference was that 1 reinforcer was 10 times larger than the other. After 6 sessions, the authors changed the contingency schedule to either an extinction condition, a variable-time schedule, or a different variable-interval schedule, to assess how participants' responses persisted when reinforcement contingencies were systematically changed. The results were consistent with the predictions of behavioral momentum. The participants not only biased their responses in favor of the more densely reinforcing key, but when contingencies changed, they showed significantly biased responses. Results supported the conclusion that healthy older adults allocate their behaviors in a manner very sensitive to training stimuli conditions; consistent with the basic principles of behavioral momentum, they show a degree of resistance to change in their behaviors when the behavioral contingencies are altered. PMID:10368942
8. 脐带间充质干细胞对裸鼠胸腺发育的作用及机制%Effects and mechanisms of human umbilical cord-derived mesenchymal stem cells on the thymus development in nude mice
Institute of Scientific and Technical Information of China (English)
王黎明; 王立华; 李铭; 王倩云; 杨洁; 刘广洋; 丛秀丽; 刘拥军
2014-01-01
背景：自身免疫性疾病的传统治疗方法很难有效解决患者免疫耐受机制缺失的问题。间充质干细胞具有再生修复实质组织器官和免疫调节的生物学特性。目的：探讨人脐带源间充质干细胞对裸鼠胸腺发育的影响及作用机制。方法：采用腹腔注射的方式向Foxn1-/-的BABL/c裸鼠体内注射人脐带源间充质干细胞，2×106/只，分析治疗后裸鼠胸腺残基的组织结构变化、胸腺上皮细胞的分布及成熟度，以及发育后的胸腺成熟淋巴细胞输出功能，并探讨人脐带源间充质干细胞发挥治疗作用的机制。结果与结论：胸腺残基出现了清晰的皮髓质结构，胸腺上皮细胞数量增加并且胸腺输出功能增强，外周血中调节性T细胞增多。其作用机制可能是由于人脐带源间充质干细胞能够定植在胸腺组织内并且表达多种促进胸腺发育的细胞因子，尤其是对胸腺发育非常重要的角质形成细胞生长因子。结果表明人脐带源间充质干细胞能够为裸鼠胸腺的结构发育和功能成熟提供合适的微环境，促进裸鼠胸腺残基的发育和功能成熟，为间充质干细胞治疗免疫性疾病的作用机制提出了新的理论观点。%BACKGROUND:For autoimmune diseases, it is difficult to effectively solve the lack of immunological tolerance in patients by traditional treatments. Mesenchymal stem cells have the biological functions of tissue and organ regeneration and immune regulation. OBJECTIVE:To explore the effects and mechanisms of human umbilical cord-derived mesenchymal stem cells on the development of thymus in nude mice. METHODS:Human umbilical cord-derived mesenchymal stem cells were intraperitoneal y injected into BABL/c nude mice at a dose of 2×106 per mouse. We analyzed the maturation and distribution of thymic epithelial cells in the thymus rudiment of nude mice and the thymopoiesis of this newly developed thymus rudiment
9. Age-related changes in the morphology and protein expression of the thymus of healthy yaks (Bos grunniens).
Science.gov (United States)
Zhang, Qian; Yang, Kun; Yangyang, Pan; He, Junfeng; Yu, Sijiu; Cui, Yan
2016-06-01
OBJECTIVE To evaluate age-related changes in the morphology and expression of cluster of differentiation 3 (CD3), S100 β, and caspase-3 of the thymus of healthy yaks (Bos grunniens). ANIMALS 15 healthy male yaks of various ages from highland plateaus. PROCEDURES Yaks were allocated to 3 groups on the basis of age (newborn [1 to 7 days old; n = 5], juvenile [5 to 7 months old, 5], and adult [3 to 4 years old; 5]) and euthanized. The thymus was harvested from each yak within 10 minutes after euthanasia. Morphological characteristics were assessed by histologic examination and transmission electron microscopy. Expression of CD3, S100 β, and caspase-3 mRNA and protein was measured by quantitative real-time PCR assay, Western blot analysis, and immunohistochemical staining. RESULTS As age increased, functional thymic tissue was replaced with adipose and connective tissues and the thymic capsule thickened. Expression of CD3 and S100 β mRNA and protein decreased with age, whereas expression of caspase-3 mRNA and protein increased with age. Immunohistochemical staining revealed that CD3-positive thymocytes were located within both the thymic cortex and medulla, S100 β-positive thymic dendritic cells were located in the corticomedullary junction and medulla, and caspase-3-positive thymocytes were diffusely scattered throughout the cortex and medulla. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that age-related thymic changes in yaks that live on highland plateaus were similar to those observed in humans and other mammals. Thus, yaks might serve as a model to study thymic immune system adaptations to high elevations. PMID:27227493
10. Computer tomographic examination of the thymus
International Nuclear Information System (INIS)
The diagnostic value of CT in follicular thymic hyperplasia and in thymomas in 8 patients with myasthenia gravis and in 12 patients without myasthenia gravis suffering from thymic tumors was evaluated by correlating CT-findings to surgical results and pathological-histological findings. Thymic size of the six patients with histologically proven follicular hyperplasia were scattered within the normal range, but half of them were at the upper limit. Thymic tumors were differentiated between invasive and non invasive tumors by CT staging. Solid tumors with different histology could not be further classified; the attenuation values ranging from 15-55 HU were the same in tumors, follicular hyperplasia and normal thymus. (orig.)
11. Human herpesvirus 7 is a constitutive inhabitant of adult human saliva.
OpenAIRE
Wyatt, L S; Frenkel, N
1992-01-01
We report the frequent isolation of human herpesvirus 7 from the saliva of healthy adults. Virus isolates recovered from different individuals exhibited minimal restriction enzyme polymorphism, which was mostly confined to heterogeneous (het) sequences in the genome. DNAs of isolates recovered from the same individual over a period of several months showed the same characteristic het fragments, indicating the stability of the het sequences upon virus replication and shedding in vivo. In contr...
12. A biokinetic model for systemic technetium in adult humans
International Nuclear Information System (INIS)
The International Commission on Radiological Protection (ICRP) currently is updating its biokinetic and dosimetric models for internally deposited radionuclides. Technetium (Tc), the lightest element that exists only in radioactive form, has two important isotopes from the standpoint of potential risk to humans: the long-lived isotope99Tm(T1/2=2.1x105 y) is present in high concentration in nuclear waste, and the short-lived isotope 99mTc (T1/2=6.02 h) is the most commonly used radionuclide in diagnostic nuclear medicine. This paper reviews data on the biological behavior of technetium and proposes a biokinetic model for systemic technetium in the adult human body for use in radiation protection. Compared with the ICRP s current occupational model for systemic technetium, the proposed model provides a more realistic description of the paths of movement of technetium in the body; provides greater consistency with experimental and medical data; and, for most radiosensitive organs, yields substantially different estimates of cumulative activity (total radioactive decays within the organ) following uptake of 99Tm or 99mTc to blood
13. CLINICAl AND IMMUNOPATHOLOGICAL.OGICAI. STUDY ON THE THYMUS IN MYASTHENIA GRAVIS
Institute of Scientific and Technical Information of China (English)
Lai-Hui Tu; Ren-Qin; Tao Wu
2000-01-01
Objective Directing towards the thymus and emphasizing mainly on the clinical and immunopathofogical study to probe its actior of the diagnosis,treatmeant and pathogcnesis cfmyasthema gravis(MG). Results tnd Dicusslons I .Diagnosis of MG with thymus pathologic lesions: I.MG with thymus hyetplasta It was shown by midstemum. CT scanning Germinal center arises from B ceil was determined by immunohistologic stain(Tol 5 marked); 2MG with thymoma It usualy occures at midaged man and apt to relapses on myasthenic crises. Positive rate of serum CAE-Ab(anti-citric acid extract antibody of human skeletal musie) was used tc find small thymoma early Rabbit Anti-serum against human CAE was labeled to determine thymoma AgNOR(argyrophilic stain of nuclear organizer region)was used to differentiate bemgn and maligant thymoma .As Muller-Hermlink' s classfication.thymoma of cortical type occurred more common and reliable to infiltration Ⅱ Treatment of MG with thymus pathoiogic lestons Except for symptomatic treatment with anti-acytlecholine drugs.MPSS or CTX intravenous perfusion had effect to relieve the myasthenic cnsis Using thymus radiation therapy to 134 cases, the complete remission and remarkable improvement rates were 66.5%.Rhe long-term effect followed up was rather stable. Using percutanous paracentesis into thymus gland for intervention treatment to 13 cases, all of them showed effect within one week.10 cases followed up more than 3 years,9 cases were complete remission or remarkable improvement Thymectmy is still a basic therapy for MG.In 102 cases with thymectomy,the complete remission and remarkable improvement rates were 59.8%,mortanty was 176%.Continual observation of CAE-Ab could contribute to determine the pateint' s prognosis,9 patients in severe condition followed up within 3 years,their serum CAE-Ab antibody titers persisted at high lever,3 Of them died,but 7 patients followed up within I year,those of their serum antibodies decreased quickly,5 cases of them
14. Professional Fulfillment and Satisfaction of US and Canadian Adult Education and Human Resource Development Faculty
Science.gov (United States)
Peterson, Shari L.; Wiesenberg, Faye
2004-01-01
This comparative study explored the professional fulfillment and job satisfaction of US and Canadian college and university faculty in the fields of Adult Education and Human Resource Development. In Autumn 2001, we disseminated electronically "The Adult Education and Human Resource Development Faculty Survey" to a selected sample of Canadian and…
15. What Are the Risk Factors for Thymus Cancer?
Science.gov (United States)
... cancer? What are the risk factors for thymus cancer? A risk factor is anything that affects your chance of getting ... Back to top » Guide Topics What Is Thymus Cancer? Causes, Risk Factors, and Prevention Early Detection, Diagnosis, and Staging Treating ...
16. Chemical Composition of Essential Oilsof Thymus and Mentha Speciesand Their Antifungal Activities
Directory of Open Access Journals (Sweden)
Leo J. L. D. van Griensven
2009-01-01
Full Text Available The potential antifungal effects of Thymus vulgaris L., Thymus tosevii L., Mentha spicata L., and Mentha piperita L. (Labiatae essential oils and their components against 17 micromycetal food poisoning, plant, animal and human pathogens are presented. The essential oils were obtained by hydrodestillation of dried plant material. Their composition was determined by GC-MS. Identification of individual constituents was made by comparison with analytical standards, and by computer matching mass spectral data with those of the Wiley/NBS Library of Mass Spectra. MIC’s and MFC’s of the oils and their components were determined by dilution assays. Thymol (48.9% and p-cymene (19.0% were the main components of T. vulgaris, while carvacrol (12.8%, a-terpinyl acetate (12.3%, cis-myrtanol (11.2% and thymol (10.4% were dominant in T. tosevii. Both Thymus species showed very strong antifungal activities. In M. piperita oil menthol (37.4%, menthyl acetate (17.4% and menthone (12.7% were the main components, whereas those of M. spicata oil were carvone (69.5% and menthone (21.9%. Mentha sp. showed strong antifungal activities, however lower than Thymus sp. The commercial fungicide, bifonazole, used as a control, had much lower antifungal activity than the oils and components investigated. It is concluded that essential oils of Thymus and Mentha species possess great antifungal potential and could be used as natural preservatives and fungicides.
17. Effects of Thymus vulgaris Essential Oil on Decay Resistance and Quality of Iranian Table Grape
OpenAIRE
Mahsa GERANSAYEH; Younes MOSTOFI; Vahid ABDOSSI
2012-01-01
Because of greater consumer awareness and concern regarding synthetic chemical additives, foods preserved with natural additives have become popular. Medicinal plants have been used by human being since ages in traditional medicine due to their therapeutic potential and the search on medicinal plants have led the discovery of novel drug candidates used against diverse diseases. Therefore Thymus vulgaris essential oil was applied in �Bidaneh Qermez� grape cultivar at six concentrations (0, 100...
18. Convergences and divergences of thymus- and peripherally-derived regulatory T cells in cancer
OpenAIRE
ALESSIA eBUROCCHI; MARIO PAOLO COLOMBO; Silvia ePICONESE
2013-01-01
The expansion of regulatory T cells (Treg) is a common event characterizing the vast majority of human and experimental tumors and it is now well established that Treg represent a crucial hurdle for a successful immunotherapy. Treg are currently classified, according to their origin, into thymus-derived (tTreg) or peripherally induced (pTreg) cells. Controversy exists over the prevalent mechanism accounting for Treg expansion in tumors, since both tTreg proliferation and de novo pTreg differe...
19. A biokinetic model for systemic technetium in adult humans.
Science.gov (United States)
Leggett, R; Giussani, A
2015-06-01
This paper reviews biokinetic data for technetium and proposes a biokinetic model for systemic technetium in adult humans. The development of parameter values focuses on data for pertechnetate TcO(-)(4) the most commonly encountered form of technetium and the form expected to be present in body fluids. The model is intended as a default model for occupational or environmental intake of technetium, i.e. applicable in the absence of form- or site-specific information. Tissues depicted explicitly in the model include thyroid, salivary glands, stomach wall, right colon wall, liver, kidneys, and bone. Compared with the ICRP's current biokinetic model for occupational or environmental intake of technetium (ICRP 1993, 1994), the proposed model provides a more detailed and biologically realistic description of the systemic behaviour of technetium and is based on a broader set of experimental and medical data. For acute input of (99m)Tc (T(1/2) = 6.02 h) to blood, the ratios of cumulative (time-integrated) activity predicted by the current ICRP model to that predicted by the proposed model range from 0.4-7 for systemic regions addressed explicitly in both models. For acute input of (99)Tc (T(1/2) = 2.1 × 10(5) year) to blood, the corresponding ratios range from 0.2-30. PMID:25859762
20. Gut microbiota in human adults with type 2 diabetes differs from non-diabetic adults.
Directory of Open Access Journals (Sweden)
Full Text Available BACKGROUND: Recent evidence suggests that there is a link between metabolic diseases and bacterial populations in the gut. The aim of this study was to assess the differences between the composition of the intestinal microbiota in humans with type 2 diabetes and non-diabetic persons as control. METHODS AND FINDINGS: The study included 36 male adults with a broad range of age and body-mass indices (BMIs, among which 18 subjects were diagnosed with diabetes type 2. The fecal bacterial composition was investigated by real-time quantitative PCR (qPCR and in a subgroup of subjects (N = 20 by tag-encoded amplicon pyrosequencing of the V4 region of the 16S rRNA gene. The proportions of phylum Firmicutes and class Clostridia were significantly reduced in the diabetic group compared to the control group (P = 0.03. Furthermore, the ratios of Bacteroidetes to Firmicutes as well as the ratios of Bacteroides-Prevotella group to C. coccoides-E. rectale group correlated positively and significantly with plasma glucose concentration (P = 0.04 but not with BMIs. Similarly, class Betaproteobacteria was highly enriched in diabetic compared to non-diabetic persons (P = 0.02 and positively correlated with plasma glucose (P = 0.04. CONCLUSIONS: The results of this study indicate that type 2 diabetes in humans is associated with compositional changes in intestinal microbiota. The level of glucose tolerance should be considered when linking microbiota with metabolic diseases such as obesity and developing strategies to control metabolic diseases by modifying the gut microbiota.
1. PARTICIPANT’S ASSESSMENT TOWARDS HUMAN DEVELOPMENT ADULT EDUCATION PROGRAM IN MALAYSIA
OpenAIRE
Abdul Razaq Ahmad; Norhasni Zainal Abiddin; Wan Hasmah Wan Mamat
2009-01-01
Adult education has been sidelined by mainstream educational researchers in Malaysia. The purpose of this article was to survey the effect of Society Development Department (KEMAS) adult education from the participants’ perspectives. The focus was on the participants’ achievements in cognitive, affective, and skill in the KEMAS programs especially in Human Development. Human intellectual is an important resource to develop a country. Thus, this study was used to focus on human development t...
2. Primary Adult Human Retinal Pigment Epithelial Cell Cultures on Human Amniotic Membranes
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Singhal Shweta
2005-01-01
Full Text Available Purpose: Retinal pigment epithelial (RPE cells grow well on surfaces that provide an extracellular matrix. Our aim was to establish primary adult human RPE cell cultures that retain their epithelial morphology in vitro using human amniotic membrane (hAM as substrate. Materials and Methods: Human cadaver eyeballs (16 were obtained from the eye bank after corneal trephination. RPE cells were harvested by a mechanical dissection of the inner choroid surface (10, group 1 or by b enzymatic digestion using 0.25% Trypsin/0.02% EDTA (6, group 2. The cells were explanted onto de-epithelialized hAM, nourished using DMEM/HAMS F-12 media and monitored for growth under the phase contrast microscope. Cell cultures were characterised by whole mount studies and paraffin sections. Growth data in the two groups were compared using the students′ ′t′ test. Results: Eleven samples (68.75% showed positive cultures with small, hexagonal cells arising from around the explant which formed a confluent and progressively pigmented monolayer. Whole mounts showed closely placed polygonal cells with heavily pigmented cytoplasm and indistinct nuclei. The histologic sections showed monolayers of cuboidal epithelium with variable pigmentation within the cytoplasm. Growth was seen by day 6-23 (average 11.5 days in the mechanical group, significantly earlier ( P Conclusions: Primary adult human RPE cell cultures retain epithelial morphology in vitro when cultured on human amniotic membranes . Mechanical dissection of the inner choroid surface appears to be an effective method of isolating RPE cells and yields earlier growth in cultures as compared to isolation by enzymatic digestion
3. HISTOLOGICAL SEXUAL DIFFERENCES IN ADULT HUMAN PARATHYROID GLANDS
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Fating Anita
2014-07-01
Full Text Available CONTEXT (BACKGROUND: Increasing problems of calcium deficiency with physiological conditions like pregnancy, lactation etc. it becomes the need of time to focus attention towards these glands as one of the essential entity. Hence we have undertaken this study to have an idea about normal variation in the gland as per sex. AIMS: To reveal sexual differences in adult human parathyroid glands. METHODS AND MATERIAL: Parathyroid glands from 25 autopsied cases of 20 to 59 years were studied after staining with Hematoxylin & Eosin, Masson’s Trichrome & Reticulin stains. STATISTICAL ANALYSIS: Data is analyzed on statistical software intercooled STATA version 8.0. Data was presented in mean± standard deviation & categorical variables were expressed in percentages. Comparison of oxyphil scores in male & female was done by unpaired‘t’ test. P < 0.05 was taken as statistical significance. RESULTS: Stroma composed of short often branching reticular fibres along with blood vessels and fat cells. By statistical examination the amount of fat was more in case of females than in males of same age groups. Oxyphil cells being less numerous than chief cells were distinguished by their dark eosinophilic, granular cytoplasm and were arranged mostly in closely packed groups without interstitial fat in between the cells. Oxyphil cells also found as placed singly among chief cells. It was also observed as continuous masses or anastomosing columns. As compared with males oxyphil cells are more in females. CONCLUSIONS: By statistical analysis 1 Percentage of stromal fat in case of females was slightly greater than in males of same age group. 2 The score of oxyphil cells in females was double to more than triple as compared to male score of same age group. 3 This study is clinically important as hormonal changes occurs early in females than in males and it is in favor of providing supplementary calcium with D3 along with minimal dose of estrogen as age advances in
4. Nanosized fibers' effect on adult human articular chondrocytes behavior
International Nuclear Information System (INIS)
Tissue engineering with chondrogenic cell based therapies is an expanding field with the intention of treating cartilage defects. It has been suggested that scaffolds used in cartilage tissue engineering influence cellular behavior and thus the long-term clinical outcome. The objective of this study was to assess whether chondrocyte attachment, proliferation and post-expansion re-differentiation could be influenced by the size of the fibers presented to the cells in a scaffold. Polylactic acid (PLA) scaffolds with different fiber morphologies were produced, i.e. microfiber (MS) scaffolds as well as nanofiber-coated microfiber scaffold (NMS). Adult human articular chondrocytes were cultured in the scaffolds in vitro up to 28 days, and the resulting constructs were assessed histologically, immunohistochemically, and biochemically. Attachment of cells and serum proteins to the scaffolds was affected by the architecture. The results point toward nano-patterning onto the microfibers influencing proliferation of the chondrocytes, and the overall 3D environment having a greater influence on the re-differentiation. In the efforts of finding the optimal scaffold for cartilage tissue engineering, studies as the current contribute to the knowledge of how to affect and control chondrocytes behavior. - Highlights: ► Chondrocyte behavior in nanofiber-coated microfiber versus microfiber scaffolds ► High porosity (> 90%) and large pore sizes (a few hundred μm) of nanofibrous scaffolds ► Proliferation enhanced by presence of nanofibers ► Differentiation not significantly affected ► Cell attachment improved in presence of both nanofibers and serum
5. Expression of cell cycle and apoptosis regulators in thymus and thymic epithelial tumors.
Science.gov (United States)
Papoudou-Bai, Alexandra; Barbouti, Alexandra; Galani, Vassiliki; Stefanaki, Kalliopi; Rontogianni, Dimitra; Kanavaros, Panagiotis
2016-05-01
The human thymus supports the production of self-tolerant T cells with competent and regulatory functions. Various cellular components of the thymic microenvironment such as thymic epithelial cells (TEC) and dendritic cells play essential roles in thymic T cell differentiation. The multiple cellular events occurring during thymic T cell and TEC differentiation involve proteins regulating cell cycle and apoptosis. Dysregulation of the cell cycle and apoptosis networks is involved in the pathogenesis of thymic epithelial tumors (TET) which are divided into two broad categories, thymomas and thymic carcinomas. The present review focuses on the usefulness of the analysis of the expression patterns of major cell cycle and apoptosis regulators in order to gain insight in the histophysiology of thymus and the histopathology, the clinical behavior and the biology of TET. PMID:25794494
6. Thymus involvement in immune system adaptive response to fractionated low-level γ-radiation
International Nuclear Information System (INIS)
In experiments with normal and thymoctomized rats it has been revealed that exposure of normal animals to 0.35 Gy of γ-radiation induces changes in blood cells subsets, depression of NK functional activity, decrease in polymorphonuclear leukocyte basal chemiluminescence level, supression of the delayed type of hypersensitivity reaction and stimulation of local IgE-synthesis in respiratory organs. At the same time irradiation of adult thymectomized animals did not resulted in significant fluctuations in cellular and humoral immunity indices as well as blood cells functional activity level. Some mechanisms of radiation-induced immune system disturbances mediate via thymus are discussed
7. Brain stem auditory evoked responses in human infants and adults
Science.gov (United States)
Hecox, K.; Galambos, R.
1974-01-01
Brain stem evoked potentials were recorded by conventional scalp electrodes in infants (3 weeks to 3 years of age) and adults. The latency of one of the major response components (wave V) is shown to be a function both of click intensity and the age of the subject; this latency at a given signal strength shortens postnatally to reach the adult value (about 6 msec) by 12 to 18 months of age. The demonstrated reliability and limited variability of these brain stem electrophysiological responses provide the basis for an optimistic estimate of their usefulness as an objective method for assessing hearing in infants and adults.
8. Reaching beyond the United States: Adventures in International Adult Education and Human Resource Development
Science.gov (United States)
Henschke, John A.
2005-01-01
In this article, the author shares his experience of how travel and adult education merged, for him, into a major emphasis in international adult education (AE) and human resource development (HRD). International ventures have been some of the most exciting and learning-filled aspects of the author's career in AE and HRD. His involvement in…
9. Expression of T cell antigen receptor genes in the thymus of irradiated mice after bone marrow transplantation
International Nuclear Information System (INIS)
Sequential appearance of the expression of T cell antigen receptor genes was investigated in the thymus of irradiated mice at the early stage after transplantation of Thy-1 congeneic H-2 compatible allogeneic bone marrow cells. The first cells to repopulate the thymus on day 7 after bone marrow transplantation were intrathymic radioresistant T cell precursors, which expanded mainly to CD4+CD8+ host-type thymocytes by day 14. A high level of gamma gene expression but a much reduced level of alpha and beta gene expression were detected in the host-type thymocytes on day 7. During regeneration of these cells, gamma-chain messages fell to low level and alpha and beta mRNA levels increased. The thymus of the recipients began to be repopulated by donor-derived T cells about 2 wk after bone marrow transplantation and was almost completely replaced by the third week. An ordered expression of gamma then beta and alpha-chain gene transcript was also observed in the donor-type thymocytes at the early stage after bone marrow transplantation. The use of thymocytes at early stage in whole-body irradiated bone marrow chimera provides a pertinent source for investigating the molecular mechanism of T cell differentiation in adult thymus
10. In vitro multiplication and essential oil composition of Thymus moroderi Pau ex Martinez, an endemic Spanish plant
OpenAIRE
Marco Medina, Ana; Casas Martínez, José Luis
2015-01-01
Thymus moroderi Pau ex Martínez (Lamiaceae) is a species endemic to South-eastern Spain valuable for its use in traditional medicine and in the production of a liqueur called cantueso. We describe a rapid and reliable in vitro propagation protocol for this species, starting from wild adult vegetative explants. Sterilization and establishment of in vitro culture were shown to be extremely difficult because of the high presence of contamination and the inability of non-contaminated explants to ...
11. Propagation of Adult SSCs: From Mouse to Human
OpenAIRE
Martin, Laura A.; Marco Seandel
2013-01-01
Adult spermatogonial stem cells (SSCs) represent a distinctive source of stem cells in mammals for several reasons. First, by giving rise to spermatogenesis, SSCs are responsible for the propagation of a father’s genetic material. As such, autologous SSCs have been considered for treatment of infertility and other purposes, including correction of inherited disorders. Second, adult spermatogonia can spontaneously produce embryonic-like stem cells in vitro, which could be used a...
12. Three chemokine receptors cooperatively regulate homing of hematopoietic progenitors to the embryonic mouse thymus
OpenAIRE
Calderón, Lesly; Boehm, Thomas
2011-01-01
The thymus lacks self-renewing hematopoietic cells, and thymopoiesis fails rapidly when the migration of progenitor cells to the thymus ceases. Hence, the process of thymus homing is an essential step for T-cell development and cellular immunity. Despite decades of research, the molecular details of thymus homing have not been elucidated fully. Here, we show that chemotaxis is the key mechanism regulating thymus homing in the mouse embryo. We determined the number of early thymic progenitors ...
13. Isolation of alveolar epithelial type II progenitor cells from adult human lungs
OpenAIRE
Fujino, Naoya; Kubo, Hiroshi; Suzuki, Takaya; Ota, Chiharu; Hegab, Ahmed E.; He, Mei; Suzuki, Satoshi; Suzuki, Takashi; Yamada, Mitsuhiro; Kondo, Takashi; Kato, Hidemasa; Yamaya, Mutsuo
2010-01-01
Resident stem/progenitor cells in the lung are important for tissue homeostasis and repair. However, a progenitor population for alveolar type II (ATII) cells in adult human lungs has not been identified. The aim of this study is to isolate progenitor cells from adult human lungs with the ability to differentiate into ATII cells. We isolated colony-forming cells that had the capability for self-renewal and the potential to generate ATII cells in vitro. These undifferentiated progenitor cells ...
14. Intercalation of Epinephrine with Calf-thymus ds-DNA
Institute of Scientific and Technical Information of China (English)
2001-01-01
A strong interaction between double stranded calf-thymus DNA (ds-DNA) and epinephrine but no interaction between single stranded calf-thymus DNA (ss-DNA) and epinephrine were observed by the use of UV-spectroscopy and cyclic voltammetry. It is suggested that the interaction leads to an intercalation of EP molecules into the groove of ds-DNA and the formation of ds-DNA(EP)n complex.
15. Microsatellites for genetic and taxonomic research on thyme (Thymus L.)
OpenAIRE
Karaca, Mehmet; İNCE, Ayşe Gül; AYDIN, Adnan; ELMASULU, Safinaz Y.; TURGUT, Kenan
2015-01-01
Microsatellites are considered the marker of choice in modern research. However, there is no application of microsatellites in the research on the genus Thymus due to the scarcity of specific primer pairs. Using in silico data of several genera in the family Lamiaceae, 23 microsatellite primer pairs (LT) were developed and evaluated in 48 samples representing 9 species and subspecies of the genus Thymus. Codominant and multiallelic LT microsatellite markers were not only useful in the determi...
Directory of Open Access Journals (Sweden)
Harish A. Wankhede
2014-09-01
Full Text Available Background: The basilar artery is the large median and major artery of the posterior circulation of the brain. Many variations are seen in the basilar artery, majority of them in position, origin and shape of the artery. Many authors have documented various anomalies as well as differences of the anatomy in this area in the Indian population as compared to the Western literature. Context and purpose of study: Many studies are available on the anterior circulation of the brain i.e. on vessels of the circle of Willis but studies on the posterior circulation are very few. And such studies so far had been done mostly in the American and European races and are mostly based on imaging techniques. Studies in the Indian population have been few. Hence the present study is concentrated on the morphological study of the basilar artery of human adult brain, to show the frequency and type of variations in the morphology of the basilar artery. Results: The basilar artery most commonly takes origin from the vertebral artery where left vertebral artery is greater in size than the right vertebral artery (72.5%. Level of formation of the basilar artery is most commonly observed at the ponto-medullary junction (62.5%. Length of the basilar artery varied from minimum 2.4cm to maximum 3.6cm. More commonly artery lies in the range of 2.6-3.0cm (57.5%. Diameter of the basilar artery at origin ranges from 3.2-4.2mm, at mid level from 3-4mm and at termination 3.1-4mm. Level of termination of the basilar artery is more commonly at the mid brain-pons junction (50%. Most of the basilar arteries are of straight type (55% and next common is bent or curved type (37.5%. Fenestration of 4mm is seen in proximal part of the one basilar artery (2.5%. Conclusion: Variations of the basilar artery are common. Neurosurgical importance of this study lies during the exposure of the region for different purposes. Knowledge of the vascular variations will increase the success of the
17. Radiographical diagnosis of the thymus in myasthenia gravis
International Nuclear Information System (INIS)
Comparison of radiographical findings of the thymus between pneumomediastinography and computed tomography were studied in 35 patients with myasthenia gravis. The patients consisted of 10 patients with thymoma and 25 without thymoma confirmed at the operations. Pneumomediastinography was very useful to discern whether the thymoma was invasive or noninvasive, but not contributory to know whether the thymus was composed of folicular lymphoid hyperplasia or normal thyimic tissues. Computed tomography was also useful to dertermine the localization and the invasiveness of the thymoma, but not helpful to know whether the thymus was of follicular lymphoid hyperplasia or normal tissues. However, the finding of ''reticular pattern''-many small nodules scattered resicularly in the thymus-in computed tomography could be regarded as a sign suggesting follicular lymphoid hyperplasia of the thymus. Therfore, both pneumomediastinography and computed tomography were very useful in the diagnosis of the localization and the invasiveness of the thymoma but not for the diagnosis of follicular lymphoid hyperplasia of the thymus. Neverethless the finding of ''reticular pattern'' computred tomography was helpful in the diagnosis of follicular lymphoid hyperplasia. (author)
18. T-cell reconstitution after thymus xenotransplantation induces hair depigmentation and loss.
Science.gov (United States)
Furmanski, Anna L; O'Shaughnessy, Ryan F L; Saldana, Jose Ignacio; Blundell, Michael P; Thrasher, Adrian J; Sebire, Neil J; Davies, E Graham; Crompton, Tessa
2013-05-01
Here we present a mouse model for T-cell targeting of hair follicles, linking the pathogenesis of alopecia to that of depigmentation disorders. Clinically, thymus transplantation has been successfully used to treat T-cell immunodeficiency in congenital athymia, but is associated with autoimmunity. We established a mouse model of thymus transplantation by subcutaneously implanting human thymus tissue into athymic C57BL/6 nude mice. These xenografts supported mouse T-cell development. Surprisingly, we did not detect multiorgan autoimmune disease. However, in all transplanted mice, we noted a striking depigmentation and loss of hair follicles. Transfer of T cells from transplanted nudes to syngeneic black-coated RAG(-/-) recipients caused progressive, persistent coat-hair whitening, which preceded patchy hair loss in depigmented areas. Further transfer experiments revealed that these phenomena could be induced by CD4+ T cells alone. Immunofluorescent analysis suggested that Trp2+ melanocyte-lineage cells were decreased in depigmented hair follicles, and pathogenic T cells upregulated activation markers when exposed to C57BL/6 melanocytes in vitro, suggesting that these T cells are not tolerant to self-melanocyte antigens. Our data raise interesting questions about the mechanisms underlying tissue-specific tolerance to skin antigens. PMID:23303453
19. A critical overview on Thymus daenensis Celak.:phytochemical and pharmacological investigations
Institute of Scientific and Technical Information of China (English)
2015-01-01
Thymus daenensis Celak. is an herb endemic to Iran belonging to the Lamiaceae family. Growing in many parts of Iran, the plant is extensively used in folk medicine. This review was performed to compile phytochemical and pharmacological data of T. daenensis. Databases such as PubMed, Scopus, Web of Science, ScienceDirect, Scientiifc Information Database, Embase, IranMedex and Google Scholar were searched for the terms“Thymus daenensis”and“Avishan-e-denai”up to 1st January 2014. Fol owing reported ethnopharmacological uses, various T. daenensis preparations have been investigated for antimicrobial, antioxidant, insecticidal and immunomodulatory effects in recent studies. Moreover, numerous studies have been published on the composition of the herb’s essential oil, focusing either on environmental parameters or preparation methods. Due to its high concentration of thymol, the plant’s essential oil possesses high antimicrobial activities on human pathogenic strains. However, comprehensive studies on the toxicity and teratogenicity as wel as clinical efifcacy of Thymus daenensis are missing.
20. A critical overview on Thymus daenensis Celak.: phytochemical and pharmacological investigations.
Science.gov (United States)
2015-03-01
Thymus daenensis Celak. is an herb endemic to Iran belonging to the Lamiaceae family. Growing in many parts of Iran, the plant is extensively used in folk medicine. This review was performed to compile phytochemical and pharmacological data of T. daenensis. Databases such as PubMed, Scopus, Web of Science, ScienceDirect, Scientific Information Database, Embase, IranMedex and Google Scholar were searched for the terms "Thymus daenensis" and "Avishan-e-denaii" up to 1st January 2014. Following reported ethnopharmacological uses, various T. daenensis preparations have been investigated for antimicrobial, antioxidant, insecticidal and immunomodulatory effects in recent studies. Moreover, numerous studies have been published on the composition of the herb's essential oil, focusing either on environmental parameters or preparation methods. Due to its high concentration of thymol, the plant's essential oil possesses high antimicrobial activities on human pathogenic strains. However, comprehensive studies on the toxicity and teratogenicity as well as clinical efficacy of Thymus daenensis are missing. PMID:25797639
1. Psychosocial factors are associated with the antibody response to both thymus-dependent and thymus-independent vaccines
OpenAIRE
Gallagher, Stephen; Phillips, Anna C.; Ferraro, Alastair J; Drayson, Mark T; Carroll, Douglas
2008-01-01
The present study examined the association between psychological stress, social support and antibody response to both thymus-dependent and thymus-independent vaccinations. Stressful life events in the previous year and customary social support were measured by standard questionnaires at baseline in 75 (41 females) healthy students. Antibody status was assessed at baseline, 4 and 18 weeks following vaccination with formaldehyde inactivated hepatitis A virus and pneumococcal polysaccharides, wh...
2. Monocular Visual Deprivation Suppresses Excitability in Adult Human Visual Cortex
DEFF Research Database (Denmark)
Lou, Astrid Rosenstand; Madsen, Kristoffer Hougaard; Paulson, Olaf Bjarne;
2011-01-01
The adult visual cortex maintains a substantial potential for plasticity in response to a change in visual input. For instance, transcranial magnetic stimulation (TMS) studies have shown that binocular deprivation (BD) increases the cortical excitability for inducing phosphenes with TMS. Here, we...... employed TMS to trace plastic changes in adult visual cortex before, during, and after 48 h of monocular deprivation (MD) of the right dominant eye. In healthy adult volunteers, MD-induced changes in visual cortex excitability were probed with paired-pulse TMS applied to the left and right occipital cortex....... Stimulus–response curves were constructed by recording the intensity of the reported phosphenes evoked in the contralateral visual field at range of TMS intensities. Phosphene measurements revealed that MD produced a rapid and robust decrease in cortical excitability relative to a control condition without...
3. The Human Function Compunction: Teleological Explanation in Adults
Science.gov (United States)
Kelemen, Deborah; Rosset, Evelyn
2009-01-01
Research has found that children possess a broad bias in favor of teleological--or purpose-based--explanations of natural phenomena. The current two experiments explored whether adults implicitly possess a similar bias. In Study 1, undergraduates judged a series of statements as "good" (i.e., correct) or "bad" (i.e., incorrect) explanations for…
4. Thymus size at 6 months of age and subsequent child mortality
DEFF Research Database (Denmark)
Garly, M.L.; Trautner, S.L.; Marx, C.; Danebod, K.; Nielsen, J.; Ravn, Henrik; Martins, C.L.; Bale, C.; Aaby, P.; Lisse, I.M.
2008-01-01
Guinea-Bissau. RESULTS: Thymus size was strongly associated with anthropometric measurements. Boys had larger thymuses than girls, controlling for anthropometry. Crying during sonography made the thymus appear smaller. Children who were not vaccinated with Bacille Calmette-Guerin (BCG) or were vaccinated......OBJECTIVE: To examine determinants of thymus size at age 6 months and investigate whether thymus size at this age is a determinant of subsequent mortality. STUDY DESIGN: Thymus size was measured by transsternal sonography in 923 6-month-old children participating in a measles vaccination trial in...... with BCG in the preceding 4 weeks before inclusion into the study had larger thymuses. Children who had malaria or had been treated with chloroquine or Quinimax in the previous week before inclusion had smaller thymuses. Controlled for background factors associated with thymus size and mortality, small...
5. The entry of the prothymocyte into the thymus after lethal irradiation and bone marrow transplantation. 2
International Nuclear Information System (INIS)
The time of entry of prothymocytes into the thymus after lethal irradiation and bone marrow transplantation (BMT) was determined by exposing the thymus only or the whole body with the thymus shielded to a second irradiation after different intervals. The repopulation of the thymus by donor type cells was determined by a thymus repopulation assay using donor specific markers. Reirradiation of the thymus kills the prothymocytes that have entered the thymus during the interval. It was found that reirradiation of the thymus from 48 hours after BMT onwards increasingly delayed thymus regeneration. This shows that donor prothymocytes do not enter the thymus until about 2 days after BMT and that they continue to do so during at least 3 subsequent days. In the second reirradiation protocol thymus regeneration occurred earlier in the shielded thymus than in thymuses of whole body irradiated mice. Earlier thymus regeneration was not seen in mice that were reirradiated at 24 hours after BMT, but occurred only when irradiation took place at 48 hours and later. These data are consistent with those obtained in the first protocol. The results are in contradiction with results of direct homing experiments, which showed entrance of donor cells within 3 hours after BMT. A functional assay demonstrated that the early appearing cells cannot be prothymocytes. In retransplantation experiments it was shown that the bone marrow may indeed be the initial homing site of prothymocytes. 14 refs.; 5 figs.; 1 table
6. Effects of proteolysis on the adenosinetriphosphatase activities of thymus myosin
Energy Technology Data Exchange (ETDEWEB)
Vu, N.D.; Wagner, P.D.
1987-07-28
Limited proteolysis was used to identify regions on the heavy chains of calf thymus myosin which may be involved in ATP and actin binding. Assignments of the various proteolytic fragments to different parts of the myosin heavy chain were based on solubility, gel filtration, electron microscopy, and binding of /sup 32/P-labeled regulatory light chains. Chymotrypsin rapidly cleaved within the head of thymus myosin to give a 70,000-dalton N-terminal fragment and a 140,000-dalton C-terminal fragment. These two fragments did not dissociate under nondenaturing conditions. Cleavage within the myosin tail to give heavy meromyosin occurred more slowly. Cleavage at the site 70,000 daltons from the N-terminus of the heavy chain caused about a 30-fold decrease in the actin concentration required to achieve half-maximal stimulation of the magnesium-adenosinetriphosphatase (Mg-ATPase) activity of unphosphorylated thymus myosin. The actin-activated ATPase activity of this digested myosin was only slightly affected by light chain phosphorylation. Actin inhibited the cleavage at this site by chymotrypsin. In the presence of ATP, chymotrypsin rapidly cleaved the thymus myosin heavy chain at an additional site about 4000 daltons from the N-terminus. Cleavage at this site caused a 2-fold increase in the ethylenediaminetetraacetic acid-ATPase activity and 3-fold decreases in the Ca/sup 2 +/- and Mg-ATPase activities of thymus myosin. Thus, cleavage at the N-terminus of thymus myosin was affected by ATP, and this cleavage altered ATPase activity. Papain cleaved the thymus myosin heavy chain about 94,000 daltons from the N-terminus to give subfragment 1. Although this subfragment 1 contained intact light chains, its actin-activated ATPase activity was not affected by light chain phosphorylation.
Energy Technology Data Exchange (ETDEWEB)
Ammann, A.J.; Wara, W.M.; Wara, D.W.; Phillips, T.L.
1977-07-01
Removal of, or irradiation to, the thymus during the neonatal period in man has resulted in no reported adverse effects on cellular immunity, although thymectomy in neonatal experimental animals is known to produce profound immunological disturbances. Adverse effects in humans may not be recognized until several decades have passed. The immunological capabilities of 7 adults with histories of thymic irradiation as infants were evaluated; normal tests results indicated intact immune systems in all cases. The 3 women tested, however, had abnormal clinical histories, including 2 with multiple tumors and 1 with chronic mucocutaneous candidiasis.
International Nuclear Information System (INIS)
Removal of, or irradiation to, the thymus during the neonatal period in man has resulted in no reported adverse effects on cellular immunity, although thymectomy in neonatal experimental animals is known to produce profound immunological disturbances. Adverse effects in humans may not be recognized until several decades have passed. The immunological capabilities of 7 adults with histories of thymic irradiation as infants were evaluated; normal tests results indicated intact immune systems in all cases. The 3 women tested, however, had abnormal clinical histories, including 2 with multiple tumors and 1 with chronic mucocutaneous candidiasis
9. Molecular Mechanism of Adult Neurogenesis and its Association with Human Brain Diseases.
Science.gov (United States)
Liu, He; Song, Ni
2016-01-01
Recent advances in neuroscience challenge the old dogma that neurogenesis occurs only during embryonic development. Mounting evidence suggests that functional neurogenesis occurs throughout adulthood. This review article discusses molecular factors that affect adult neurogenesis, including morphogens, growth factors, neurotransmitters, transcription factors, and epigenetic factors. Furthermore, we summarize and compare current evidence of associations between adult neurogenesis and human brain diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and brain tumors. PMID:27375363
Institute of Scientific and Technical Information of China (English)
张乃春
2014-01-01
Objective To investigate the clinical characteristics of patients infected with human adenovirus type 7 and to provide guidance for early diagnosis and timely control of the outbreak.Methods A total of 301 patients infected with the human adenoviruses who were quarantined in hospital from December 2012 to February 2013 were observed.Epidemiological questionnaires were used to collect data of clinical features of the disease including
11. The weight of nations: an estimation of adult human biomass
OpenAIRE
Walpole Sarah; Prieto-Merino David; Edwards Phil; Cleland John; Stevens Gretchen; Roberts Ian
2012-01-01
Abstract Background The energy requirement of species at each trophic level in an ecological pyramid is a function of the number of organisms and their average mass. Regarding human populations, although considerable attention is given to estimating the number of people, much less is given to estimating average mass, despite evidence that average body mass is increasing. We estimate global human biomass, its distribution by region and the proportion of biomass due to overweight and obesity. M...
12. Carcinoma showing thymus-like differentiation of the thyroid (CASTLE).
Science.gov (United States)
Huang, Chuying; Wang, Li; Wang, Yan; Yang, Xibiao; Li, Qiu
2013-10-01
Carcinoma showing thymus-like differentiation (CASTLE) is a rare intrathyroidal neoplasm, probably arising from ectopic thymus or branchial pouch remnants. The tumor was first reported by Miyauchi et al. [1].The clinical and pathological features of this tumor were classified by Chan et al. [2] into 4 groups: ectopic hamartomatous thymoma, ectopic cervical thymoma, spindle ephithelial tumor with thymic-like differentiation (SETTLE), and carcinoma showing thymus-like differentiation (CASTLE). Recently, CASTLE has been designated as an independent clinicopathologic entity of thyroid tumors in the most recent edition of the World Health Organization classification of tumors of endocrine organs[3].To our knowledge, less than 100 cases of CASTLE have been reported in the literature, 45 cases of which (including one of the authors' patient) have been identified in China. We report a new case of this entity and suggest recommendations for diagnosis. PMID:23920320
13. A century of trends in adult human height
Science.gov (United States)
2016-01-01
Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3–19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8–144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries. DOI: http://dx.doi.org/10.7554/eLife.13410.001 PMID:27458798
14. Convergences and Divergences of Thymus- and Peripherally Derived Regulatory T Cells in Cancer
OpenAIRE
Burocchi, Alessia; Colombo, Mario P.; Piconese, Silvia
2013-01-01
The expansion of regulatory T cells (Treg) is a common event characterizing the vast majority of human and experimental tumors and it is now well established that Treg represent a crucial hurdle for a successful immunotherapy. Treg are currently classified, according to their origin, into thymus-derived Treg (tTreg) or peripherally induced Treg (pTreg) cells. Controversy exists over the prevalent mechanism accounting for Treg expansion in tumors, since both tTreg proliferation and de novo pTr...
15. Development and application of the Chinese adult female computational phantom Rad-HUMAN
International Nuclear Information System (INIS)
Rad-HUMAN is a whole-body numerical phantom of a Chinese adult woman which contains 46 organs and tissues and was created by MCAM6 software using the color photographs of the Chinese Visible Human dataset. This dataset was obtained from a 22-year old Chinese female cadaver judged to represent normal human anatomy as much as possible. The density and elemental composition recommended in the ICRP Publication 89 and in the ICRU report 44 were assigned to the organ and tissue in Rad-HUMAN for radiation protection purpose. The last step was to implement the anatomical data into a Monte Carlo code. Rad-HUMAN contains more than 28.8 billion tiny volume units, which produces an accurately whole-body numerical phantom of a Chinese adult female
16. Coxsackievirus B4 Infection of Murine Foetal Thymus Organ Cultures
OpenAIRE
Brilot, F; Jaidane, H.; Geenen, Vincent; Hober, D
2008-01-01
The infection of foetal thymus with coxsackievirus B4 (CV-B4) E2 has been studied ex vivo by using CD-1 mice on foetal day 14, as a ready source of organs for experimentation to investigate the hypothesis of the role of thymic viral infections in the pathogenesis of type 1 diabetes. The replication of CV-B4 E2 in murine foetal thymus organ cultures has been demonstrated by evaluating the levels of positive- and negative-stranded viral RNA in cells by using a real-time quantitative RT-PCR meth...
17. ALTERED HISTOLOGY OF THE THYMUS AND SPLEEN IN CONTAMINANT-EXPOSED JUVENILE AMERICAN ALLIGATORS
Science.gov (United States)
Morphological difference in spleen and thymus are closely related to functional immune differences. Hormonal regulation of the immune system has been demonstrated in reptilian splenic and thymic tissue. Spleens and thymus were obtained from juvenile alligators at two reference si...
18. Happiness, depression and human benevolence beliefs in institutionalized and non institutionalized major adults
Directory of Open Access Journals (Sweden)
Walter L. Arias
2013-12-01
Full Text Available In this study we analyze the relations between happiness, depression and human benevolence beliefs in a group of major people who live in asylums (24 and others who live with their families (38. We use Lima’s happiness scale, Yesavage’s Geriatric depression scale and Belief in human scale. We found that there were no significant differences between two groups of major adults in depression levels, but in happiness, positive sense of life and satisfaction with life, non institutionalized older adults had higher punctuations than major people who lived in asylums.
19. The human traffickers and exploitation of children and young adults.
Directory of Open Access Journals (Sweden)
Sara Scala
2012-06-01
Full Text Available The article focuses on the traffic of children, who are kidnapped, cheated and purchased by their families to be exploited in many ways. These victims have severe mental and physical traumas. Many of them, slaves of their exploiters, remain invisible and live their lifes without fundamental rights and without any kind of support or help. The traffic in human beings is a new kind of slavery, which acts in the dark, is criminal and involves different subjects of different ages, different nationalities and generations. The traffic in human beings is managed by transnational criminal organizations and is a disturbing and growing phenomena around the world.
20. Gut microbiota in human adults with type 2 diabetes differs from non-diabetic adults
DEFF Research Database (Denmark)
Larsen, Nadja; Vogensen, Finn Kvist; van der Berg, Franciscus Winfried J;
2010-01-01
Background Recent evidence suggests that there is a link between metabolic diseases and bacterial populations in the gut. The aim of this study was to assess the differences between the composition of the intestinal microbiota in humans with type 2 diabetes and non-diabetic persons as control...... control metabolic diseases by modifying the gut microbiota....... = 0.04). Conclusions The results of this study indicate that type 2 diabetes in humans is associated with compositional changes in intestinal microbiota. The level of glucose tolerance should be considered when linking microbiota with metabolic diseases such as obesity and developing strategies to...
1. Two animated adult human voxel phantoms based on polygon mesh surfaces
International Nuclear Information System (INIS)
Among computational models used in radiation protection, voxel phantoms based on computer tomographic (CT), nuclear magnetic resonance (NMR) or colour photographic images, became very popular in recent years. Although being a true to nature representation of the scanned individual the scanning is usually made in supine position, which causes a shift of internal organs towards the ribcage, a compression of the lungs and a reduction of the sagittal diameter especially in the abdominal region compared to the anatomy of a person in upright standing position, which in turn can influence absorbed or equivalent dose estimates. This study proposes a method for human phantom design using tools recently developed in the areas of computer graphics and animated films and applies them to the creation and modelling of artificial 3 D human organs and tissues. Two animated models, a male and a female adult human phantom have been developed based on anatomical atlases, observing at the same time the anatomical specifications published by the International Commission on Radiological Protection for the male and female reference adult. The phantoms are called FAXAA (Female Adult voXelAverage-Average) and MAXAA (Male Adult voXelAverage-Average) because they represent female and male adults with average weight and average height. (author)
2. Canonical Genetic Signatures of the Adult Human Brain
OpenAIRE
Hawrylycz, Michael; Miller, Jeremy A.; Menon, Vilas; Feng, David; Dolbeare, Tim; Guillozet-Bongaarts, Angela L.; Anil G. Jegga; Aronow, Bruce J.; Lee, Chang-Kyu; Bernard, Amy; Glasser, Matthew F.; Dierker, Donna L; Menche, Jörge; Szafer, Aaron; Collman, Forrest
2015-01-01
The structure and function of the human brain are highly stereotyped, implying a conserved molecular program responsible for its development, cellular structure, and function. We applied a correlation-based metric of “differential stability” (DS) to assess reproducibility of gene expression patterning across 132 structures in six individual brains, revealing meso-scale genetic organization. The highest DS genes are highly biologically relevant, with enrichment for brain-related biological ann...
3. Testosterone affects language areas of the adult human brain.
Science.gov (United States)
Hahn, Andreas; Kranz, Georg S; Sladky, Ronald; Kaufmann, Ulrike; Ganger, Sebastian; Hummer, Allan; Seiger, Rene; Spies, Marie; Vanicek, Thomas; Winkler, Dietmar; Kasper, Siegfried; Windischberger, Christian; Swaab, Dick F; Lanzenberger, Rupert
2016-05-01
Although the sex steroid hormone testosterone is integrally involved in the development of language processing, ethical considerations mostly limit investigations to single hormone administrations. To circumvent this issue we assessed the influence of continuous high-dose hormone application in adult female-to-male transsexuals. Subjects underwent magnetic resonance imaging before and after 4 weeks of testosterone treatment, with each scan including structural, diffusion weighted and functional imaging. Voxel-based morphometry analysis showed decreased gray matter volume with increasing levels of bioavailable testosterone exclusively in Broca's and Wernicke's areas. Particularly, this may link known sex differences in language performance to the influence of testosterone on relevant brain regions. Using probabilistic tractography, we further observed that longitudinal changes in testosterone negatively predicted changes in mean diffusivity of the corresponding structural connection passing through the extreme capsule. Considering a related increase in myelin staining in rodents, this potentially reflects a strengthening of the fiber tract particularly involved in language comprehension. Finally, functional images at resting-state were evaluated, showing increased functional connectivity between the two brain regions with increasing testosterone levels. These findings suggest testosterone-dependent neuroplastic adaptations in adulthood within language-specific brain regions and connections. Importantly, deteriorations in gray matter volume seem to be compensated by enhancement of corresponding structural and functional connectivity. Hum Brain Mapp 37:1738-1748, 2016. © 2016 Wiley Periodicals, Inc. PMID:26876303
4. Adult human neural stem cell therapeutics： Currentdevelopmental status and prospect
Institute of Scientific and Technical Information of China (English)
Hyun Nam; Kee-Hang Lee; Do-Hyun Nam; Kyeung Min Joo
2015-01-01
Over the past two decades, regenerative therapies usingstem cell technologies have been developed for variousneurological diseases. Although stem cell therapy is anattractive option to reverse neural tissue damage and torecover neurological deficits, it is still under developmentso as not to show significant treatment effects in clinicalsettings. In this review, we discuss the scientific andclinical basics of adult neural stem cells （aNSCs）, andtheir current developmental status as cell therapeuticsfor neurological disease. Compared with other typesof stem cells, aNSCs have clinical advantages, suchas limited proliferation, inborn differentiation potentialinto functional neural cells, and no ethical issues. Inspite of the merits of aNSCs, difficulties in the isolationfrom the normal brain, and in the in vitro expansion,have blocked preclinical and clinical study using aNSCs.However, several groups have recently developed noveltechniques to isolate and expand aNSCs from normaladult brains, and showed successful applications ofaNSCs to neurological diseases. With new technologiesfor aNSCs and their clinical strengths, previous hurdlesin stem cell therapies for neurological diseases could beovercome, to realize clinically efficacious regenerativestem cell therapeutics.
5. Human-derived neural progenitors functionally replace astrocytes in adult mice
OpenAIRE
Chen, Hong; Qian, Kun; Chen, Wei; Hu, Baoyang; Blackbourn, Lisle W.; Du, Zhongwei; Ma, Lixiang; Liu, Huisheng; Knobel, Karla M.; Ayala, Melvin; Zhang, Su-Chun
2015-01-01
Astrocytes are integral components of the homeostatic neural network as well as active participants in pathogenesis of and recovery from nearly all neurological conditions. Evolutionarily, compared with lower vertebrates and nonhuman primates, humans have an increased astrocyte-to-neuron ratio; however, a lack of effective models has hindered the study of the complex roles of human astrocytes in intact adult animals. Here, we demonstrated that after transplantation into the cervical spinal co...
6. Shifts in human skin and nares microbiota of healthy children and adults
OpenAIRE
Oh, Julia; Conlan, Sean; Polley, Eric C.; Segre, Julia A.; Kong, Heidi H.
2012-01-01
Background Characterization of the topographical and temporal diversity of the microbial collective (microbiome) hosted by healthy human skin established a reference for studying disease-causing microbiomes. Physiologic changes occur in the skin as humans mature from infancy to adulthood. Thus, characterizations of adult microbiomes might have limitations when considering pediatric disorders such as atopic dermatitis (AD) or issues such as sites of microbial carriage. The objective of this st...
7. Happiness, depression and human benevolence beliefs in institutionalized and non institutionalized major adults
OpenAIRE
Walter L. Arias; Luis Yepez; Ana L. Núñez; Adriana Oblitas; Susana Pinedo; María A. Masías; Joice Hurtado
2013-01-01
In this study we analyze the relations between happiness, depression and human benevolence beliefs in a group of major people who live in asylums (24) and others who live with their families (38). We use Lima’s happiness scale, Yesavage’s Geriatric depression scale and Belief in human scale. We found that there were no significant differences between two groups of major adults in depression levels, but in happiness, positive sense of life and satisfaction with life, non institutionalized olde...
8. Chemical compositions of two different Thymus species essential oils
Directory of Open Access Journals (Sweden)
Samira Jaberi
2015-06-01
Full Text Available Thymus is one of the most important members of Lamiaceae family. Aerial parts of the plant have been widely used in medicine. It has been reported that most of these effects are related to phenolic compounds especially thymol and carvacrol in Thymus essential oil. In this study, aerial parts of Thymus daenensis and Thymus lancifolius were collected from Kohgiluyeh and Boyer-Ahmad, Iran. Essential oils of aerial parts of these plants were gained by the hydrodistillation method and the chemical compositions were analyzed by gas chromatography/ Mass spectrometry (GC/MS. The major components of the essential oil of T. daenensis were thymol (39.91%, carvacrol (29.93%, linalool (5.55%, caryophyllene (3.5% and geraniol (3.09%, whereas the major components of the essential oil of T. lancifolius were: carvacrol (25.55%, thymol (20.79%, linalool (16.8%, α-terpineol (6.34%, borneol (4.00%, caryophyllene (3.98%, p-cymene (3.38% and cis-linalool oxide (3.21%. Linalool was reported as another major component in T. lancifolius
9. Cavernous hemangioma in the thymus: a case report.
Science.gov (United States)
Ose, Naoko; Kobori, Yuko; Takeuchi, Yukiyasu; Susaki, Yoshiyuki; Taniguchi, Seiji; Maeda, Hajime
2016-12-01
Cavernous hemangioma is not a neoplasm, but rather a congenital venous malformation with the potential to develop in all parts of the body, though it is very rarely seen in the thymus. We report a case of cavernous hemangioma in the thymus partially resected. A 71-year-old woman presented with pericardial discomfort, and chest computed tomography (CT) showed a left lateral mediastinal mass which was 2.0 × 1.2 × 1.8 cm in size, with border regularity and without calcification. Its interior was partially enhanced. Three-dimensional chest computed tomography image showed a tortuous vessel connecting to the tumor. Surgical resection was performed for the purpose of providing a definitive diagnosis and treatment because a mediastinal tumor such as thymoma or teratoma was suspected. Partial resection of the thymus including the mass was done by utilizing a three-port, left-sided video-assisted thoracic surgery (VATS) approach with hoisting of the third rib with the patient in a spinal position. A wine-colored mass bulging from the surface of the left lobe of the thymus was identified along with the communicating vessel which could only be cut with an energy device. It is considered that thymic partial resection using VATS is a better option for small and non-infiltrative lesions. PMID:26943686
10. Carcinoid tumor of the thymus visualized with I 131-MIBG
International Nuclear Information System (INIS)
Iodine 131 Metaiodobenzylguanidine is usually used in the diagnosis of pheochromocytoma, neuroblastoma and bronchus and gut carcinoid tumors. This radiopharmaceutical is sometimes applied in therapy. We report the case of a patient with an exceptional carcinoid tumor of the thymus studied by I 131-MIBG scintigraphy before and after surgery. The results are in agreement with the other investigations
11. The effects of heavy ion irradiation on medaka thymus
International Nuclear Information System (INIS)
Medaka is a teleost fish native to the Asian countries. It has long been the study object of biology in various fields including radiation biology, especially in Japan. Documented data on radiation effects in the medaka system are accumulating. Recently, the establishment of a transgenic medaka, rag ragl-egfp, makes it possible to directly visualize the thymus in vivo in a real time manner. In our previous investigation, decrease in the volume of thymus was confirmed in the ragl-egfp medaka after exposure to a dose from 5 to 10 Gy of X-rays. To comparatively study the effects between low and high linear energy transfer (LET) irradiations on medaka thymus, in the present work, irradiations from accelerated Fe ions was verified. A total of 24 medaka fish were used in the control and the experimental groups exposed to a dose of 0.5, 1, 2, or 5 Gy. The preliminary data obtained so far showed that decrease in the volume of thymus in few medaka could be detectable in the 0.5 Gy-irradiated group, while this effect was observable in all the medaka receiving a dose at 2 Gy or more. Further investigations are needed to determine the relative biological effectiveness (RBE) of Fe-ion irradiations in this system. (author)
12. An Assessemnt of Graduate Adult Education and Human Resource Development Programs: A U.S. Perspective
Science.gov (United States)
Akdere, Mesut; Conceicao, Simone C. O.
2009-01-01
Due to recent changes in the workplace, the workforce and higher education have driven academic programs of adult education (AE) and human resource development (HRD) in the U.S. to become more integrated as part of the mission of institutions of higher education. In this exploratory study, existing graduate programs in AE and HRD in the U.S. were…
13. An Instrument Development Model for Online Surveys in Human Resource Development and Adult Education
Science.gov (United States)
Strachota, Elaine M.; Conceicao, Simone C. O.; Schmidt, Steven W.
2006-01-01
This article describes the use of a schematic model for developing and distributing online surveys. Two empirical studies that developed and implemented online surveys to collect data to measure satisfaction in various aspects of human resource development and adult education exemplify the use of the model to conduct online survey research. The…
14. Equality and Human Capital: Conflicting Concepts within State-Funded Adult Education in Ireland
Science.gov (United States)
Hurley, Kevin
2015-01-01
This article offers a critique of the concept of equality as it informs the White Paper on Adult Education: Learning for Life (2000). It also outlines the extent to which human capital theory can be seen to have effectively colonised lifelong learning from the outset of its adoption by the European Union with highly constraining implications for…
15. Plasticity of adult human pancreatic duct cells by neurogenin3-mediated reprogramming
DEFF Research Database (Denmark)
Swales, Nathalie; Martens, Geert A; Bonné, Stefan;
2012-01-01
Duct cells isolated from adult human pancreas can be reprogrammed to express islet beta cell genes by adenoviral transduction of the developmental transcription factor neurogenin3 (Ngn3). In this study we aimed to fully characterize the extent of this reprogramming and intended to improve it....
16. Bridging the Gap between Human Resource Development and Adult Education: Part One, Assumptions, Definitions, and Critiques
Science.gov (United States)
Hatcher, Tim; Bowles, Tuere
2013-01-01
Human resource development (HRD) as a scholarly endeavor and as a practice is often criticized in the adult education (AE) literature and by AE scholars as manipulative and oppressive and, through training and other interventions, controlling workers for strictly economic ends (Baptiste, 2001; Cunningham, 2004; Schied, 2001; Welton, 1995).…
17. Concept Maps: Practice Applications in Adult Education and Human Resource Development
Science.gov (United States)
Daley, Barbara J.
2010-01-01
Concept maps can be used as both a cognitive and constructivist learning strategy in teaching and learning in adult education and human resource development. The maps can be used to understand course readings, analyze case studies, develop reflective thinking and enhance research skills. The creation of concept maps can also be supported by the…
18. Perspectives on Adult Education, Human Resource Development, and the Emergence of Workforce Development
Science.gov (United States)
Jacobs, Ronald L.
2014-01-01
This article presents a perspective on the relationship between adult education and human resource development of the past two decades and the subsequent emergence of workforce development. The lesson taken from the article should be more than simply a recounting of events related to these fields of study. Instead, the more general lesson may be…
19. Bridging the Gap between Human Resource Development and Adult Education: Part Two, the Critical Turn
Science.gov (United States)
Hatcher, Tim; Bowles, Tuere
2014-01-01
Human resource development (HRD) as a scholarly endeavor and as a practice is often criticized in the adult education (AE) literature and by AE scholars as manipulative and oppressive and, through training and other interventions, controlling workers for strictly economic ends (Baptiste, 2001; Cunningham, 2004; Schied, 2001; Welton, 1995). The…
20. Profile of the Adult Education and Human Resource Development Professoriate: Characteristics and Professional Fulfillment.
Science.gov (United States)
Peterson, Shari L.; Provo, Joanne
1998-01-01
A survey of 113 members of the Commission of Professors of Adult Education and 50 of the Academy of Human Resource Development found few differences except in age, rank, and salary. The two faculties are compatible and could be integrated. Overall job satisfaction is high. Professors tended to come from other fields and to remain. (SK)
1. Human-derived neural progenitors functionally replace astrocytes in adult mice
Science.gov (United States)
Chen, Hong; Qian, Kun; Chen, Wei; Hu, Baoyang; Blackbourn, Lisle W.; Du, Zhongwei; Ma, Lixiang; Liu, Huisheng; Knobel, Karla M.; Ayala, Melvin; Zhang, Su-Chun
2015-01-01
Astrocytes are integral components of the homeostatic neural network as well as active participants in pathogenesis of and recovery from nearly all neurological conditions. Evolutionarily, compared with lower vertebrates and nonhuman primates, humans have an increased astrocyte-to-neuron ratio; however, a lack of effective models has hindered the study of the complex roles of human astrocytes in intact adult animals. Here, we demonstrated that after transplantation into the cervical spinal cords of adult mice with severe combined immunodeficiency (SCID), human pluripotent stem cell–derived (PSC-derived) neural progenitors migrate a long distance and differentiate to astrocytes that nearly replace their mouse counterparts over a 9-month period. The human PSC-derived astrocytes formed networks through their processes, encircled endogenous neurons, and extended end feet that wrapped around blood vessels without altering locomotion behaviors, suggesting structural, and potentially functional, integration into the adult mouse spinal cord. Furthermore, in SCID mice transplanted with neural progenitors derived from induced PSCs from patients with ALS, astrocytes were generated and distributed to a similar degree as that seen in mice transplanted with healthy progenitors; however, these mice exhibited motor deficit, highlighting functional integration of the human-derived astrocytes. Together, these results indicate that this chimeric animal model has potential for further investigating the roles of human astrocytes in disease pathogenesis and repair. PMID:25642771
Science.gov (United States)
Tallone, Tiziano; Realini, Claudio; Böhmler, Andreas; Kornfeld, Christopher; Vassalli, Giuseppe; Moccetti, Tiziano; Bardelli, Silvana; Soldati, Gianni
2011-04-01
Multipotent mesenchymal stromal cells (MSCs) are a type of adult stem cells that can be easily isolated from various tissues and expanded in vitro. Many reports on their pluripotency and possible clinical applications have raised hopes and interest in MSCs. In an attempt to unify the terminology and the criteria to label a cell as MSC, in 2006 the International Society for Cellular Therapy (ISCT) proposed a standard set of rules to define the identity of these cells. However, MSCs are still extracted from different tissues, by diverse isolation protocols, are cultured and expanded in different media and conditions. All these variables may have profound effects on the selection of cell types and the composition of heterogeneous subpopulations, on the selective expansion of specific cell populations with totally different potentials and ergo, on the long-term fate of the cells upon in vitro culture. Therefore, specific molecular and cellular markers that identify MSCs subsets as well as standardization of expansion protocols for these cells are urgently needed. Here, we briefly discuss new useful markers and recent data supporting the rapidly emerging concept that many different types of progenitor cells are found in close association with blood vessels. This knowledge may promote the necessary technical improvements required to reduce variability and promote higher efficacy and safety when isolating and expanding these cells for therapeutic use. In the light of the discussed data, particularly the identification of new markers, and advances in the understanding of fundamental MSC biology, we also suggest a revision of the 2006 ISCT criteria. PMID:21327755
3. Canonical genetic signatures of the adult human brain.
Science.gov (United States)
Hawrylycz, Michael; Miller, Jeremy A; Menon, Vilas; Feng, David; Dolbeare, Tim; Guillozet-Bongaarts, Angela L; Jegga, Anil G; Aronow, Bruce J; Lee, Chang-Kyu; Bernard, Amy; Glasser, Matthew F; Dierker, Donna L; Menche, Jörg; Szafer, Aaron; Collman, Forrest; Grange, Pascal; Berman, Kenneth A; Mihalas, Stefan; Yao, Zizhen; Stewart, Lance; Barabási, Albert-László; Schulkin, Jay; Phillips, John; Ng, Lydia; Dang, Chinh; Haynor, David R; Jones, Allan; Van Essen, David C; Koch, Christof; Lein, Ed
2015-12-01
The structure and function of the human brain are highly stereotyped, implying a conserved molecular program responsible for its development, cellular structure and function. We applied a correlation-based metric called differential stability to assess reproducibility of gene expression patterning across 132 structures in six individual brains, revealing mesoscale genetic organization. The genes with the highest differential stability are highly biologically relevant, with enrichment for brain-related annotations, disease associations, drug targets and literature citations. Using genes with high differential stability, we identified 32 anatomically diverse and reproducible gene expression signatures, which represent distinct cell types, intracellular components and/or associations with neurodevelopmental and neurodegenerative disorders. Genes in neuron-associated compared to non-neuronal networks showed higher preservation between human and mouse; however, many diversely patterned genes displayed marked shifts in regulation between species. Finally, highly consistent transcriptional architecture in neocortex is correlated with resting state functional connectivity, suggesting a link between conserved gene expression and functionally relevant circuitry. PMID:26571460
4. Self-Control and Impulsiveness in Nondieting Adult Human Females: Effects of Visual Food Cues and Food Deprivation
Science.gov (United States)
Forzano, Lori-Ann B.; Chelonis, John J.; Casey, Caitlin; Forward, Marion; Stachowiak, Jacqueline A.; Wood, Jennifer
2010-01-01
Self-control can be defined as the choice of a larger, more delayed reinforcer over a smaller, less delayed reinforcer, and impulsiveness as the opposite. Previous research suggests that exposure to visual food cues affects adult humans' self-control. Previous research also suggests that food deprivation decreases adult humans' self-control. The…
5. 40 CFR 26.1705 - Prohibition of reliance on unethical human research with non-pregnant, non-nursing adults...
Science.gov (United States)
2010-07-01
... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Prohibition of reliance on unethical human research with non-pregnant, non-nursing adults conducted after April 7, 2006. 26.1705 Section 26... Prohibition of reliance on unethical human research with non-pregnant, non-nursing adults conducted...
6. 40 CFR 26.1704 - Prohibition of reliance on unethical human research with non-pregnant, non-nursing adults...
Science.gov (United States)
2010-07-01
... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Prohibition of reliance on unethical human research with non-pregnant, non-nursing adults conducted before April 7, 2006. 26.1704 Section 26... Prohibition of reliance on unethical human research with non-pregnant, non-nursing adults conducted...
7. How does thymus infection by coxsackievirus contribute to the pathogenesis of type 1 diabetes?
Directory of Open Access Journals (Sweden)
Hélène eMichaux
2015-06-01
Full Text Available Through synthesis and presentation of neuroendocrine self-antigens by major histocompatibility complex (MHC proteins, thymic epithelial cells (TECs play a crucial role in programming central immune self-tolerance to neuroendocrine functions. Insulin-like growth factor-2 (IGF-2 is the dominant gene/polypeptide of the insulin family that is expressed in TECs from different animal species and humans. Igf2 transcription is defective in the thymus of diabetes-prone Bio-Breeding (BB rats, and tolerance to insulin is severely decreased in Igf2-/- mice. For more than 15 years now, our group is investigating the hypothesis that, besides a pancreotropic action, infection by coxsackievirus B4 (CV-B4 could implicate the thymus as well, and interfere with the intrathymic programming of central tolerance to the insulin family and secondarily to insulin-secreting islet β cells. In this perspective, we have demonstrated that a productive infection of the thymus occurs after oral CV-B4 inoculation of mice. Moreover, our most recent data have demonstrated that CV-B4 infection of a murine medullary (m TEC line induces a significant decrease in Igf2 expression and IGF-2 production. In these conditions, Igf1 expression was much less affected by CV-B4 infection, while Ins2 transcription was not detected in this cell line. Through the inhibition of Igf2 expression in TECs, CV-B4 infection could lead to a breakdown of central immune tolerance to the insulin family and promote an autoimmune response against insulin-secreting islet β cells. Our major research objective now is to understand the molecular mechanisms by which CV-B4 infection of TECs leads to a major decrease in Igf2 expression in these cells.
8. Value of radiologic imaging of the thymus gland in myasthenia gravis
International Nuclear Information System (INIS)
Radiologic imaging in myasthenia gravis is used for the evaluation of pathologic changes of the thymus gland. Computed tomography can demonstrate tumors of the anterior mediastinum in nearly 90% and is therefore superior to conventional radiography.Because of the variety of size and shape of the normal thymus gland, differentiation between normal thymus, follicular hyperplasia and thymoma is rarely possible especially in younger patients. In elderly patients with myasthenia gravis and involution of the thymus gland tumors of the thymus are reliably detected by computed tomography, whereas the ability of computed tomography to predict the histological diagnosis is poor even with intravenous administration of contrast media. (orig.)
9. Larval food quantity affects the capacity of adult mosquitoes to transmit human malaria
Science.gov (United States)
Shapiro, Lillian L. M.; Murdock, Courtney C.; Jacobs, Gregory R.; Thomas, Rachel J.; Thomas, Matthew B.
2016-01-01
Adult traits of holometabolous insects are shaped by conditions experienced during larval development, which might impact interactions between adult insect hosts and parasites. However, the ecology of larval insects that vector disease remains poorly understood. Here, we used Anopheles stephensi mosquitoes and the human malaria parasite Plasmodium falciparum, to investigate whether larval conditions affect the capacity of adult mosquitoes to transmit malaria. We reared larvae in two groups; one group received a standard laboratory rearing diet, whereas the other received a reduced diet. Emerging adult females were then provided an infectious blood meal. We assessed mosquito longevity, parasite development rate and prevalence of infectious mosquitoes over time. Reduced larval food led to increased adult mortality and caused a delay in parasite development and a slowing in the rate at which parasites invaded the mosquito salivary glands, extending the time it took for mosquitoes to become infectious. Together, these effects increased transmission potential of mosquitoes in the high food regime by 260–330%. Such effects have not, to our knowledge, been shown previously for human malaria and highlight the importance of improving knowledge of larval ecology to better understand vector-borne disease transmission dynamics. PMID:27412284
10. Induction of GLUT-1 protein in adult human skeletal muscle fibers
DEFF Research Database (Denmark)
Gaster, M; Franch, J; Staehr, P;
2000-01-01
Prompted by our recent observations that GLUT-1 is expressed in fetal muscles, but not in adult muscle fibers, we decided to investigate whether GLUT-1 expression could be reactivated. We studied different stimuli concerning their ability to induce GLUT-1 expression in mature human skeletal muscle...... fibers. Metabolic stress (obesity, non-insulin-dependent diabetes mellitus), contractile activity (training), and conditions of de- and reinnervation (amyotrophic lateral sclerosis) could not induce GLUT-1 expression in human muscle fibers. However, regenerating muscle fibers in polymyositis expressed...... GLUT-1. In contrast to GLUT-1, GLUT-4 was expressed in all investigated muscle fibers. Although the significance of GLUT-1 in adult human muscle fibers appears limited, GLUT-1 may be of importance for the glucose supplies in immature and regenerating muscle....
11. Age-related changes in CT attenuation of the thymus in children
International Nuclear Information System (INIS)
Background. The CT appearance of the normal and abnormal thymus and its age-related changes have been described. However, there is no information regarding the change in thymus CT attenuation values in children. Objective. The aim of the present study was to evaluate the normal CT attenuation of the thymus in infants and children and discover when the decline begins. Materials and methods. CT attenuation values of the thymus were retrospectively evaluated in 152 children between ages of 1 day and up to 14 years. For each patient the mean value of the CT thymus attenuation was calculated and compared to CT attenuation of the chest wall and cardiac muscles. We also examined the correlation between thymic attenuation, gender, and disease. The statistical analysis used was multivariate linear regression. Results. CT attenuation of the thymus declines with age, beginning only after the 1st year of life. The thymus is more hyperdense than the chest wall and cardiac muscles in infants less than 1 year. The thymus is denser in males than females. In malignant conditions, in infants less than 1 year, thymus CT attenuation is decreased. In older children thymus attenuation was similar to that for the chest wall and cardiac muscles. Conclusion. The decline in thymic CT attenuation with age is consistent with fatty infiltration of the gland. The measurements given in this report can serve as a basis for comparison to determine whether the thymus of a young child is normal or pathological. (orig.)
12. Short-term monocular deprivation alters GABA in the adult human visual cortex.
Science.gov (United States)
Lunghi, Claudia; Emir, Uzay E; Morrone, Maria Concetta; Bridge, Holly
2015-06-01
Neuroplasticity is a fundamental property of the nervous system that is maximal early in life, within the critical period [1-3]. Resting GABAergic inhibition is necessary to trigger ocular dominance plasticity and to modulate the onset and offset of the critical period [4, 5]. GABAergic inhibition also plays a crucial role in neuroplasticity of adult animals: the balance between excitation and inhibition in the primary visual cortex (V1), measured at rest, modulates the susceptibility of ocular dominance to deprivation [6-10]. In adult humans, short-term monocular deprivation strongly modifies ocular balance, unexpectedly boosting the deprived eye, reflecting homeostatic plasticity [11, 12]. There is no direct evidence, however, to support resting GABAergic inhibition in homeostatic plasticity induced by visual deprivation. Here, we tested the hypothesis that GABAergic inhibition, measured at rest, is reduced by deprivation, as demonstrated by animal studies. GABA concentration in V1 of adult humans was measured using ultra-high-field 7T magnetic resonance spectroscopy before and after short-term monocular deprivation. After monocular deprivation, resting GABA concentration decreased in V1 but was unaltered in a control parietal area. Importantly, across participants, the decrease in GABA strongly correlated with the deprived eye perceptual boost measured by binocular rivalry. Furthermore, after deprivation, GABA concentration measured during monocular stimulation correlated with the deprived eye dominance. We suggest that reduction in resting GABAergic inhibition triggers homeostatic plasticity in adult human V1 after a brief period of abnormal visual experience. These results are potentially useful for developing new therapeutic strategies that could exploit the intrinsic residual plasticity of the adult human visual cortex. PMID:26004760
13. Neuroscience of Human Social Interactions and Adult Attachment Style
Directory of Open Access Journals (Sweden)
Pascal Vrticka
2012-07-01
Full Text Available Since its first description four decades ago, attachment theory has become one of the principal developmental psychological frameworks for describing the role of individual differences in the establishment and maintenance of social bonds between people. Yet, still little is known about the neurobiological underpinnings of attachment orientations and their well-established impact on a range of social and affective behaviors. In the present review, we summarize data from recent studies using cognitive and imaging approaches to characterize attachment styles and their effect on emotion and social cognition. We propose a functional neuroanatomical framework to integrate the key brain mechanisms involved in the perception and regulation of social emotional information, and their modulation by individual differences in terms of secure versus insecure (more specifically avoidant, anxious, or resolved vs. unresolved attachment traits. This framework describes how each individual’s attachment style (built through interactions between personal relationship history and predispositions may influence the encoding of approach versus aversion tendencies (safety versus threat in social encounters, implicating the activation of a network of subcortical (amygdala, hippocampus, striatum and cortical (insula, cingulate limbic areas. These basic and automatic affective mentalization mechanisms are in turn modulated by more elaborate and voluntary cognitive mentalization processes, subserving theory of mind, cognitive control, and emotion regulation capacities, implicating a distinct network (in medial prefrontal cortex, superior temporal sulcus, and temporo-parietal junction, among others. Such research does not only help better understand the neural underpinnings of human social behavior, but also provides important insights on psychopathological conditions where attachment dysregulations is likely to play an important (causal role.
14. Ultrastructural Evidence of Exosome Secretion by Progenitor Cells in Adult Mouse Myocardium and Adult Human Cardiospheres
Directory of Open Access Journals (Sweden)
Lucio Barile
2012-01-01
Full Text Available The demonstration of beneficial effects of cell therapy despite the persistence of only few transplanted cells in vivo suggests secreted factors may be the active component of this treatment. This so-called paracrine hypothesis is supported by observations that culture media conditioned by progenitor cells contain growth factors that mediate proangiogenic and cytoprotective effects. Cardiac progenitor cells in semi-suspension culture form spherical clusters (cardiospheres that deliver paracrine signals to neighboring cells. A key component of paracrine secretion is exosomes, membrane vesicles that are stored intracellularly in endosomal compartments and are secreted when these structures fuse with the cell plasma membrane. Exosomes have been identified as the active component of proangiogenic effects of bone marrow CD34+ stem cells in mice and the regenerative effects of embryonic mesenchymal stem cells in infarcted hearts in pigs and mice. Here, we provide electron microscopic evidence of exosome secretion by progenitor cells in mouse myocardium and human cardiospheres. Exosomes are emerging as an attractive vector of paracrine signals delivered by progenitor cells. They can be stored as an “off-the-shelf” product. As such, exosomes have the potential for circumventing many of the limitations of viable cells for therapeutic applications in regenerative medicine.
15. Morphofunctional and signaling molecules overlap of the pineal gland and thymus: role and significance in aging
Science.gov (United States)
Paltsev, Michael A.; Polyakova, Victoria O.; Kvetnoy, Igor M.; Anderson, George; Kvetnaia, Tatiana V.; Linkova, Natalia S.; Paltseva, Ekaterina M.; Rubino, Rosa; De Cosmo, Salvatore; De Cata, Angelo; Mazzoccoli, Gianluigi
2016-01-01
Deficits in neuroendocrine-immune system functioning, including alterations in pineal and thymic glands, contribute to aging-associated diseases. This study looks at ageing-associated alterations in pineal and thymic gland functioning evaluating common signaling molecules present in both human and animal pinealocytes and thymocytes: endocrine cell markers (melatonin, serotonin, pCREB, AANAT, CGRP, VIP, chromogranin A); cell renovation markers (p53, AIF, Ki67), matrix metalloproteinases (MMP2, MMP9) and lymphocytes markers (CD4, CD5, CD8, CD20). Pineal melatonin is decreased, as is one of the melatonin pathway synthesis enzymes in the thymic gland. A further similarity is the increased MMPs levels evident over age in both glands. Significant differences are evident in cell renovation processes, which deteriorate more quickly in the aged thymus versus the pineal gland. Decreases in the number of pineal B-cells and thymic T-cells were also observed over aging. Collected data indicate that cellular involution of the pineal gland and thymus show many commonalities, but also significant changes in aging-associated proteins. It is proposed that such ageing-associated alterations in these two glands provide novel pharmaceutical targets for the wide array of medical conditions that are more likely to emerge over the course of ageing. PMID:26943046
16. Morphofunctional and signaling molecules overlap of the pineal gland and thymus: role and significance in aging.
Science.gov (United States)
Paltsev, Michael A; Polyakova, Victoria O; Kvetnoy, Igor M; Anderson, George; Kvetnaia, Tatiana V; Linkova, Natalia S; Paltseva, Ekaterina M; Rubino, Rosa; De Cosmo, Salvatore; De Cata, Angelo; Mazzoccoli, Gianluigi
2016-03-15
Deficits in neuroendocrine-immune system functioning, including alterations in pineal and thymic glands, contribute to aging-associated diseases. This study looks at ageing-associated alterations in pineal and thymic gland functioning evaluating common signaling molecules present in both human and animal pinealocytes and thymocytes: endocrine cell markers (melatonin, serotonin, pCREB, AANAT, CGRP, VIP, chromogranin Ð); cell renovation markers (p53, AIF, Ki67), matrix metalloproteinases (MMP2, MMP9) and lymphocytes markers (CD4, CD5, CD8, CD20). Pineal melatonin is decreased, as is one of the melatonin pathway synthesis enzymes in the thymic gland. A further similarity is the increased MMPs levels evident over age in both glands. Significant differences are evident in cell renovation processes, which deteriorate more quickly in the aged thymus versus the pineal gland. Decreases in the number of pineal B-cells and thymic T-cells were also observed over aging. Collected data indicate that cellular involution of the pineal gland and thymus show many commonalities, but also significant changes in aging-associated proteins. It is proposed that such ageing-associated alterations in these two glands provide novel pharmaceutical targets for the wide array of medical conditions that are more likely to emerge over the course of ageing. PMID:26943046
17. Immuno-localisation of anti-thyroid antibodies in adult human cerebral cortex.
Science.gov (United States)
Moodley, Kogie; Botha, Julia; Raidoo, Deshandra Munsamy; Naidoo, Strinivasen
2011-03-15
Expression of thyroid-stimulating hormone receptor (TSH-R) has been demonstrated in adipocytes, lymphocytes, bone, kidney, heart, intestine and rat brain. Immuno-reactive TSH-R has been localised in rat brain and human embryonic cerebral cortex but not in adult human brain. We designed a pilot study to determine whether anti-thyroid auto-antibodies immuno-localise in normal adult human cerebral cortex. Forensic samples from the frontal, motor, sensory, occipital, cingulate and parieto-occipito-temporal association cortices were obtained from five individuals who had died of trauma. Although there were no head injuries, the prior psychiatric history of patients was unknown. The tissues were probed with commercial antibodies against both human TSH-R and human thyroglobulin (TG). Anti-TSH-R IgG immuno-localised to cell bodies and axons of large neurones in all 6 regions of all 5 brains. The intensity and percentage of neurones labelled were similar in all tissue sections. TSH-R immuno-label was also observed in vascular endothelial cells in the cingulate gyrus. Although also found in all 5 brains and all six cortical regions, TG localised exclusively in vascular smooth muscle cells and not on neurones. Although limited by the small sample size and number of brain areas examined, this is the first study describing the presence of antigenic targets for anti-TSH-R IgG on human cortical neurons, and anti-TG IgG in cerebral vasculature. PMID:21196016
18. Identification and characterization of neuroblasts in the subventricular zone and rostral migratory stream of the adult human brain
Institute of Scientific and Technical Information of China (English)
Congmin Wang; Qiangqiang Zhang; Yue Zhang; Rui Chen; Hongjun Song; Zhengang Yang; Fang Liu; Ying-Ying Liu; Cai-Hong Zhao; Yan You; Lei Wang; Jingxiao Zhang; Bin Wei; Tong Ma
2011-01-01
It is of great interest to identify new neurons in the adult human brain,but the persistence of neurogenesis in the subventricular zone (SVZ) and the existence of the rostral migratory stream (RMS)-like pathway in the adult human forebrain remain highly controversial.In the present study,we have described the general configuration of the RMS in adult monkey,fetal human and adult human brains.We provide evidence that neuroblasts exist continuously in the anterior ventral SVZ and RMS of the adult human brain.The neuroblasts appear singly or in pairs without forming chains; they exhibit migratory morphologies and co-express the immature neuronal markers doublecortin,polysialylated neural cell adhesion molecule and βI-tubulin.Few of these neuroblasts appear to be actively proliferating in the anterior ventral SVZ but none in the RMS,indicating that neuroblasts distributed along the RMS are most likely derived from the ventral SVZ.Interestingly,no neuroblasts are found in the adult human olfactory bulb.Taken together,our data suggest that the SVZ maintains the ability to produce neuroblasts in the adult human brain.
19. Gap junction modulation by extracellular signaling molecules: the thymus model
Directory of Open Access Journals (Sweden)
Alves L.A.
2000-01-01
Full Text Available Gap junctions are intercellular channels which connect adjacent cells and allow direct exchange of molecules of low molecular weight between them. Such a communication has been described as fundamental in many systems due to its importance in coordination, proliferation and differentiation. Recently, it has been shown that gap junctional intercellular communication (GJIC can be modulated by several extracellular soluble factors such as classical hormones, neurotransmitters, interleukins, growth factors and some paracrine substances. Herein, we discuss some aspects of the general modulation of GJIC by extracellular messenger molecules and more particularly the regulation of such communication in the thymus gland. Additionally, we discuss recent data concerning the study of different neuropeptides and hormones in the modulation of GJIC in thymic epithelial cells. We also suggest that the thymus may be viewed as a model to study the modulation of gap junction communication by different extracellular messengers involved in non-classical circuits, since this organ is under bidirectional neuroimmunoendocrine control.
20. Regeneration of the aged thymus by a single transcription factor
OpenAIRE
Bredenkamp, N.; Nowell, C. S.; Blackburn, C C
2014-01-01
Thymic involution is central to the decline in immune system function that occurs with age. By regenerating the thymus, it may therefore be possible to improve the ability of the aged immune system to respond to novel antigens. Recently, diminished expression of the thymic epithelial cell (TEC)-specific transcription factor Forkhead box N1 (FOXN1) has been implicated as a component of the mechanism regulating age-related involution. The effects of upregulating FOXN1 function in the aged thymu...
1. Exosomes in the Thymus: Antigen Transfer and Vesicles
OpenAIRE
Skogberg, Gabriel; Telemo, Esbjörn; Ekwall, Olov
2015-01-01
Thymocytes go through several steps of maturation and selection in the thymus in order to form a functional pool of effector T-cells and regulatory T-cells in the periphery. Close interactions between thymocytes, thymic epithelial cells, and dendritic cells are of vital importance for the maturation, selection, and lineage decision of the thymocytes. One important question that is still unanswered is how a relatively small epithelial cell population can present a vast array of self-antigens t...
2. Essential Oils Composition and Antioxidant Properties of Three Thymus Species
OpenAIRE
Hamzeh Amiri
2011-01-01
The essential oils of three wild-growing Thymus species, collected from west of Iran during the flowering stage, were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Under the optimum extraction and analysis conditions, 44, 38, and 38 constituents (mainly monoterpenes compounds) were identified in T. kotschyanus Boiss. and Hohen, T. eriocalyx (Ronniger) Jalas, and T. daenensis subsp lancifolius (Celak) Jalas which represe...
3. Supercritical CO2 extraction of essential oils from Thymus vulgaris
OpenAIRE
S. A. B. VIEIRA DE MELO; G.M.N. Costa; R. Garau; A. Casula; B. Pittau
2000-01-01
Supercritical CO2 extraction of essential oil from Thymus vulgaris leaves was studied using experimental data recently obtained in the Florys S.p.A. laboratory. Mass transfer coefficients in the supercritical and solid phases from extraction curves at 40°C and 20 MPa were evaluated using a mathematical model based on the local adsorption equilibrium of essential oil on lipid in leaves. The adsorption equilibrium constant was fitted to these experimental data, and internal and external mass tr...
4. Glandular Trichomes and Essential Oil of Thymus quinquecostatus
OpenAIRE
Ping Jia; Hanzhu Liu; Ting Gao; Hua Xin
2013-01-01
The distribution and types of glandular trichomes and essential oil chemistry of Thymus quinquecostatus were studied. The glandular trichomes are distributed on the surface of stem, leaf, rachis, calyx and corolla, except petiole, pistil and stamen. Three morphologically distinct types of glandular trichomes are described. Peltate trichomes, consisting of a basal cell, a stalk cell and a 12-celled head, are distributed on the stem, leaf, corolla and outer side of calyx. Capitate trichomes, co...
5. Evidence for a stem cell hierarchy in the adult human breast
DEFF Research Database (Denmark)
Villadsen, René; Fridriksdottir, Agla J; Rønnov-Jessen, Lone;
2007-01-01
Cellular pathways that contribute to adult human mammary gland architecture and lineages have not been previously described. In this study, we identify a candidate stem cell niche in ducts and zones containing progenitor cells in lobules. Putative stem cells residing in ducts were essentially...... laminin-rich extracellular matrix gels. Staining for the lineage markers keratins K14 and K19 further revealed multipotent cells in the stem cell zone and three lineage-restricted cell types outside this zone. Multiparameter cell sorting and functional characterization with reference to anatomical sites...... in situ confirmed this pattern. The proposal that the four cell types are indeed constituents of an as of yet undescribed stem cell hierarchy was assessed in long-term cultures in which senescence was bypassed. These findings identify an adult human breast ductal stem cell activity and its earliest...
6. Defining the role of common variation in the genomic and biological architecture of adult human height
DEFF Research Database (Denmark)
Wood, Andrew R.; Esko, Tonu; Yang, Jian;
2014-01-01
Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated similar to 2,0......TOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants....
7. Adult human neural stem cells : Properties in vitro and as xenografts in the spinal cord
OpenAIRE
Westerlund, Ulf
2005-01-01
Though the presence of stem cells in the adult human brain has been presented earlier, much has yet to be discovered about these cells. However, the mere potential of these cells has had a significant impact of how we today evaluate the regenerative capacity of the central nervous system and, importantly, on the possible means for science to provide insights in neural repair. In this thesis a series of in vitro studies, based on the formation of neurospheres, was used to...
8. Effect of exercise on fluoride metabolism in adult humans: a pilot study
OpenAIRE
Fatemeh V. Zohoori; Alison Innerd; Azevedo, Liane B; Whitford, Gary M.; Anne Maguire
2015-01-01
An understanding of all aspects of fluoride metabolism is critical to identify its biological effects and avoid fluoride toxicity in humans. Fluoride metabolism and subsequently its body retention may be affected by physiological responses to acute exercise. This pilot study investigated the effect of exercise on plasma fluoride concentration, urinary fluoride excretion and fluoride renal clearance following no exercise and three exercise intensity conditions in nine healthy adults after taki...
9. Dynamic Gene Expression in the Human Cerebral Cortex Distinguishes Children from Adults
OpenAIRE
Sterner, Kirstin N.; Weckle, Amy; Chugani, Harry T.; Tarca, Adi L.; Sherwood, Chet C.; Hof, Patrick R; Kuzawa, Christopher W.; Boddy, Amy M.; Abbas, Asad; Raaum, Ryan L.; Grégoire, Lucie; Lipovich, Leonard; Grossman, Lawrence I; Uddin, Monica; Goodman, Morris
2012-01-01
In comparison with other primate species, humans have an extended juvenile period during which the brain is more plastic. In the current study we sought to examine gene expression in the cerebral cortex during development in the context of this adaptive plasticity. We introduce an approach designed to discriminate genes with variable as opposed to uniform patterns of gene expression and found that greater inter-individual variance is observed among children than among adults. For the 337 tran...
10. The Human Adult Skeletal Muscle Transcriptional Profile Reconstructed by a Novel Computational Approach
OpenAIRE
Bortoluzzi, Stefania; d'Alessi, Fabio; Romualdi, Chiara; Danieli, Gian Antonio
2000-01-01
By applying a novel software tool, information on 4080 UniGene clusters was retrieved from three adult human skeletal muscle cDNA libraries, which were selected for being neither normalized nor subtracted. Reconstruction of a transcriptional profile of the corresponding tissue was attempted by a computational approach, classifying each transcript according to its level of expression. About 25% of the transcripts accounted for about 80% of the detected transcriptional activity, whereas most ge...
11. Telomere Length in Human Adults and High Level Natural Background Radiation
OpenAIRE
Birajalaxmi Das; Divyalakshmi Saini; Seshadri, M
2009-01-01
BACKGROUND: Telomere length is considered as a biomarker of aging, stress, cancer. It has been associated with many chronic diseases such as hypertension and diabetes. Although, telomere shortening due to ionizing radiation has been reported in vitro, no in vivo data is available on natural background radiation and its effect on telomere length. METHODOLOGY/PRINCIPAL FINDINGS: The present investigation is an attempt to determine the telomere length among human adults residing in high level na...
12. Effect of histamine on proliferation of normal human adult lung fibroblasts.
OpenAIRE
Jordana, M; Befus, A D; Newhouse, M T; Bienenstock, J; Gauldie, J
1988-01-01
Fibrotic lung tissue shows increased connective tissue deposition and fibroblast proliferation and in addition a substantial increase in mast cell numbers in and around the fibrotic area. To elucidate the question of whether products of mast cells affect the proliferative behaviour of structural cells in the lung and thereby contribute to fibrogenesis, the effect of histamine, a prominent mast cell derived mediator, on the in vitro proliferation of primary cultures of normal adult human lung ...
13. Fas and Fas ligand expression in fetal and adult human testis with normal or deranged spermatogenesis.
Science.gov (United States)
Francavilla, S; D'Abrizio, P; Rucci, N; Silvano, G; Properzi, G; Straface, E; Cordeschi, G; Necozione, S; Gnessi, L; Arizzi, M; Ulisse, S
2000-08-01
In mice, the Fas/Fas ligand (FasL) system has been shown to be involved in germ cell apoptosis. In the present study we evaluated the expression of Fas and Fas ligand (FasL) in fetal and adult human testis. Semiquantitative RT-PCR demonstrated the expression of Fas and FasL messenger ribonucleic acids in adult testis, but not in fetal testis (20-22 weeks gestation). In situ RT-PCR and immunohistochemistry experiments on adult human testis demonstrated the expression of FasL messenger ribonucleic acid and protein in Sertoli and Leydig cells, whereas the expression of Fas was confined to the Leydig cells and sporadic degenerating spermatocytes. The number of Fas-positive germ cells per 100 Sertoli cell nuclei was increased in 10 biopsies with postmeiotic germ cell arrest compared to 10 normal testis biopsies (mean, 3.82 +/- 0.45 vs. 2.02 +/- 0.29; P = 0.0001), but not in 10 biopsies with meiotic germ cell arrest (mean, 1.56 +/- 1.07). Fas and FasL proteins were not expressed in cases of idiopathic hypogonadotropic hypogonadism. Together, these findings may suggest that Fas/FasL expression in the human testis is developmentally regulated and under gonadotropin control. The increased germ cell expression of Fas in patients with postmeiotic germ cell arrest suggests that the Fas/FasL system may be involved in the quality control mechanism of the produced gametes. PMID:10946867
14. Long-Term Culture of Genome-Stable Bipotent Stem Cells from Adult Human Liver
OpenAIRE
Huch, Meritxell; Gehart, Helmuth; van Boxtel, Ruben; Hamer, Karien; Blokzijl, Francis; Verstegen, Monique M.A.; Ellis, Ewa; van Wenum, Martien; Fuchs, Sabine A.; de Ligt, Joep; van de Wetering, Marc; SASAKI, Nobuo; Boers, Susanne J.; Kemperman, Hans; de Jonge, Jeroen
2015-01-01
Summary Despite the enormous replication potential of the human liver, there are currently no culture systems available that sustain hepatocyte replication and/or function in vitro. We have shown previously that single mouse Lgr5+ liver stem cells can be expanded as epithelial organoids in vitro and can be differentiated into functional hepatocytes in vitro and in vivo. We now describe conditions allowing long-term expansion of adult bile duct-derived bipotent progenitor cells from human live...
15. The inflatable thymus herniation of the normal mediastinal thymus: A case report and review of the literature.
Science.gov (United States)
Stuut, Marijn; van Zwieten, Gusta; Straetmans, Jos M; Lacko, Martin; Stumpel, Constance T R M
2016-04-01
Anterior neck masses in young children can be a diagnostic challenge for otolaryngologists and radiologists. We present a rare case of herniation of normal mediastinal thymus in a four-year-old girl. Additional medical features as an inguinal hernia and trochlear nerve paresis raised the question whether there is a causal relationship or an association. A connective tissue disorder could not be diagnosed as possible causal factor to the abnormal movement of the mediastinal thymus. Awareness and recognition of this benign phenomenon is important in order to avoid unnecessary biopsy or surgery. Diagnosis can be confirmed by ultrasonography. Magnetic Resonance Imaging might be valuable in order to obtain more information about the extension of the mass. PMID:26968057
16. Moxidectin causes adult worm mortality of human lymphatic filarial parasite Brugia malayi in rodent models.
Science.gov (United States)
Verma, Meenakshi; Pathak, Manisha; Shahab, Mohd; Singh, Kavita; Mitra, Kalyan; Misra-Bhattacharya, Shailja
2014-12-01
Moxidectin is a macrocyclic lactone belonging to milbemycin family closely related to ivermectin and is currently progressing towards Phase III clinical trial against human infection with the filaria Onchocerca volvulus (Leuckart, 1894). There is a single report on the microfilaricidal and embryostatic activity of moxidectin in case of the human lymphatic filarial parasite Brugia malayi (Brug, 1927) in Mastomys coucha (Smith) but without any adulticidal action. In the present study, the in vitro and in vivo antifilarial efficacy of moxidectin was evaluated on, B. malayi. In vitro moxidectin showed 100% reduction in adult female worm motility at 0.6 μM concentration within 7 days with 68% inhibition in the reduction of MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide dye) (which is used to detect viability of worms). A 50% inhibitory concentration (IC50) of moxidectin for adult female parasite was 0.242 μM, for male worm 0.186 μM and for microfilaria IC50 was 0.813 μM. In adult B. malayi-transplanted primary screening model (Meriones unguiculatus Milne-Edwards), moxidectin at a single optimal dose of 20 mg/kg by oral and subcutaneous route was found effective on both adult parasites and microfilariae. In secondary screening (M coucha, subcutaneously inoculated with infective larvae), moxidectin at the same dose by subcutaneous route brought about death of 49% of adult worms besides causing sterilisation in 54% of the recovered live female worms. The treated animals exhibited a continuous and sustained reduction in peripheral blood microfilaraemia throughout the observation period of 90 days. The mechanism of action of moxidectin is suggested to be similar to avermectins. The in silico studies were also designed to explore the interaction of moxidectin with glutamate-gated chloride channels of B. malayi. The docking results revealed a close interaction of moxidectin with various GluCl ligand sites of B. malayi. PMID:25651699
17. Rabbit neonates and human adults perceive a blending 6-component odor mixture in a comparable manner.
Directory of Open Access Journals (Sweden)
Charlotte Sinding
Full Text Available Young and adult mammals are constantly exposed to chemically complex stimuli. The olfactory system allows for a dual processing of relevant information from the environment either as single odorants in mixtures (elemental perception or as mixtures of odorants as a whole (configural perception. However, it seems that human adults have certain limits in elemental perception of odor mixtures, as suggested by their inability to identify each odorant in mixtures of more than 4 components. Here, we explored some of these limits by evaluating the perception of three 6-odorant mixtures in human adults and newborn rabbits. Using free-sorting tasks in humans, we investigated the configural or elemental perception of these mixtures, or of 5-component sub-mixtures, or of the 6-odorant mixtures with modified odorants' proportion. In rabbit pups, the perception of the same mixtures was evaluated by measuring the orocephalic sucking response to the mixtures or their components after conditioning to one of these stimuli. The results revealed that one mixture, previously shown to carry the specific odor of red cordial in humans, was indeed configurally processed in humans and in rabbits while the two other 6-component mixtures were not. Moreover, in both species, such configural perception was specific not only to the 6 odorants included in the mixture but also to their respective proportion. Interestingly, rabbit neonates also responded to each odorant after conditioning to the red cordial mixture, which demonstrates their ability to perceive elements in addition to configuration in this complex mixture. Taken together, the results provide new insights related to the processing of relatively complex odor mixtures in mammals and the inter-species conservation of certain perceptual mechanisms; the results also revealed some differences in the expression of these capacities between species putatively linked to developmental and ecological constraints.
18. A Comparison between the Purpose and Goals of Human Resource Development and Adult Education: Whose Interests Are Being Served?
Science.gov (United States)
Batchelder, John Stuart; Byxbe, Ferris
2002-01-01
The purposes and goals of adult education and human resource development (HRD) differ and even clash. They find common ground in the personal development function but differ in the control and motivation for learning. Adult education seeks to enable learner self-determination; HRD's focus is enabling organizational control through employee…
19. Evaluating human papillomavirus vaccination programs in Canada: should provincial healthcare pay for voluntary adult vaccination?
Directory of Open Access Journals (Sweden)
Smith? Robert J
2008-04-01
Full Text Available Abstract Background Recently, provincial health programs in Canada and elsewhere have begun rolling out vaccination against human papillomavirus for girls aged 9–13. While vaccination is voluntary, the cost of vaccination is waived, to encourage parents to have their daughters vaccinated. Adult women who are eligible for the vaccine may still receive it, but at a cost of approximately CAN400. Given the high efficacy and immunogenicity of the vaccine, the possibility of eradicating targeted types of the virus may be feasible, assuming the vaccination programs are undertaken strategically. Methods We develop a mathematical model to describe the epidemiology of vaccination against human papillomavirus, accounting for a widespread childhood vaccination program that may be supplemented by voluntary adult vaccination. A stability analysis is performed to determine the stability of the disease-free equilibrium. The critical vaccine efficacy and immunogenicity thresholds are derived, and the minimum level of adult vaccination required for eradication of targeted types is determined. Results We demonstrate that eradication of targeted types is indeed feasible, although the burden of coverage for a childhood-only vaccination program may be high. However, if a small, but non-negligible, proportion of eligible adults can be vaccinated, then the possibility of eradication of targeted types becomes much more favourable. We provide a threshold for eradication in general communities and illustrate the results with numerical simulations. We also investigate the effects of suboptimal efficacy and immunogenicity and show that there is a critical efficacy below which eradication of targeted types is not possible. If eradication is possible, then there is a critical immunogenicity such that even 100% childhood vaccination will not eradicate the targeted types of the virus and must be supplemented with voluntary adult vaccination. However, the level of adult 20. Sulphation and glucuronidation of ritodrine in human foetal and adult tissues. Science.gov (United States) Pacifici, G M; Kubrich, M; Giuliani, L; de Vries, M; Rane, A 1993-01-01 Ritodrine is a beta 2-adrenoceptor agonist used for the management of preterm labour. It is inactivated by conjugation with sulphate and glucuronic acid. There is more ritodrine sulphate than ritodrine glucuronide in urine from the newborn whereas equal amounts of ritodrine glucuronide and sulphate are excreted in maternal urine [Clin. Pharmacol. Ther 44, 634-641, 1988]. We show that, in the mid-gestational human fetal liver, ritodrine sulphotransferase is well expressed, whereas the glucuronidation of ritodrine is little developed compared to the adult liver. The average sulphotransferase activity was 308 pmol.min-1 per mg protein in fetal (N = 48) and 145 pmol.min-1 per mg protein in adult (N = 32) liver. The rates of ritodrine sulphation in fetal gut, lung and kidney were higher than in the corresponding adult tissues. The development and tissue distribution patterns of ritodrine sulphotransferase are consistent with those of dopamine sulphotransferase. Ritodrine and dopamine are sulphated by thermolabile enzymes. The activity of glucuronyl transferase was measurable in only 5 of the 48 foetal livers assayed, and in those in which could be assayed, the average activity was 44.6 pmol.min-1 per mg protein, one-tenth of that in adult livers (524 pmol.min-1 per mg protein). PMID:8491241 1. Body size and human energy requirements: Reduced mass-specific total energy expenditure in tall adults. Science.gov (United States) Heymsfield, Steven B; Pietrobelli, Angelo 2010-01-01 Mammalian resting energy expenditure (REE) increases as approximately weight(0.75) while mass-specific REE scales as approximately weight(-0.25). Energy needs for replacing resting losses are thus less relative to weight (W) in large compared with small mammals, a classic observation with biological implications. Human weight scales as approximately height(2) and tall adults thus have a greater weight than their short counterparts. However, it remains unknown if mass-specific energy requirements are less in tall adults; allometric models linking total energy expenditure (TEE) and weight with height (H) are lacking. We tested the hypothesis that mass-specific energy requirements scale inversely to height in adults by evaluating TEE (doubly labeled water) data collected by the National Academy of Sciences. Activity energy expenditure (AEE) was calculated from TEE, REE (indirect calorimetry), and estimated diet-induced energy expenditure. Main analyses focused on nonmorbidly obese subjects TEE as a function of height (range H(1.5-1.7)) in both men and women. TEE/W scaled negatively to height ( approximately H(-0.7), P TEE (kcal/kg/d) at +/-2 SD for US height lower in tall compared with short men (40.3 vs. 46.5) and women (37.7 vs. 42.7). REE/W also scaled negatively to height in men (P human stature and energy requirements that have implications for modeling efforts and provide new links to mammalian biology as a whole. PMID:19856424 2. Postirradiation dynamics of T-lymphocyte precusors and regeneration of thymus in mice International Nuclear Information System (INIS) Irradiation of CBA mice elicits a pronounced response of intrathymus and bone marrow precursors of T-lymphocytes (PTL) which is manifested by an increase in a relative content of PTL in the thymus and their transfer from bone marrow to thymus. The estimate of the regenerative potency of the thymus most adequately reflects the cellular events leading to regeneration thereof. The differences in the thymus regeneration dynamics between CBA and AKR mice are associated with different radiation response of the intrathymic SC-1-PTL in mice of these strains 3. Achievement of Cellular Immunity and Discordant Xenogeneic Tolerance in Mice by Porcine Thymus Grafts Institute of Scientific and Technical Information of China (English) YongZhao; ZuyueSun; YiminSun; AlanN.Langnas 2004-01-01 Specific cellular immune tolerance may be essential for successful xenotransplantation in humans. Thymectomized (ATX), T and NK ceil-depleted immunocompetent mice grafted with xenogeneic fetal pig thymic and liver tissue (FP THY/LIV) result in efficient mouse thymopoiesis and peripheral repopulation of functional mouse CD4+ T cell.Very importantly, the reconstituted mouse T cells are specifically tolerant to pig donor antigens. Studies demonstrated that porcine MHCs mediated positive and negative selection of mouse thymocytes in FP THY grafts, whereas mouse MHCs were involved in negative selection in grafts. Therefore, T cell tolerance to xenogeneic donor antigens could be induced by grafting donor thymus tissue. Xenogeneic thymic replacement might have a potential role in the reconstitution of cellular immunity in patients with AIDS or other immunodeficiencies caused bv thvmus dvsfunction. 4. Limits on efficient human mindreading: convergence across Chinese adults and Semai children. Science.gov (United States) Wang, Bo; Hadi, Nur Shafiqah Abdul; Low, Jason 2015-11-01 We tested Apperly and Butterfill's (2009, Psychological Review, 116, 753) theory that humans have two mindreading systems whereby the efficient-system guiding anticipatory glances displays signature limits that do not apply to the flexible system guiding verbal predictions. Experiments 1 and 2 tested urban Mainland-Chinese adults (n = 64) and Experiment 3 tested Semai children living in the rainforests of Peninsular Malaysia (3- to 4-year-olds, n = 60). Participants - across different ages, groups and methods - anticipated others' false-beliefs about object-location but not object-identity. Convergence in signature limits signalled that the early-developing efficient system involved minimal theory-of-mind. Chinese adults and older Semai children showed flexibility in their direct predictions. The flexible mindreading system in ascribing others' beliefs as such was task-sensitive and implicated maturational and cultural contributions. PMID:25631400 5. Physical Exercise Habits Correlate with Gray Matter Volume of the Hippocampus in Healthy Adult Humans Science.gov (United States) Killgore, William D. S.; Olson, Elizabeth A.; Weber, Mareen 2013-12-01 Physical activity facilitates neurogenesis of dentate cells in the rodent hippocampus, a brain region critical for memory formation and spatial representation. Recent findings in humans also suggest that aerobic exercise can lead to increased hippocampal volume and enhanced cognitive functioning in children and elderly adults. However, the association between physical activity and hippocampal volume during the period from early adulthood through middle age has not been effectively explored. Here, we correlated the number of minutes of self-reported exercise per week with gray matter volume of the hippocampus using voxel-based morphometry (VBM) in 61 healthy adults ranging from 18 to 45 years of age. After controlling for age, gender, and total brain volume, total minutes of weekly exercise correlated significantly with volume of the right hippocampus. Findings highlight the relationship between regular physical exercise and brain structure during early to middle adulthood. 6. Extrasynaptic location of laminin beta 2 chain in developing and adult human skeletal muscle DEFF Research Database (Denmark) Wewer, U M; Thornell, L E; Loechel, F; Zhang, X; Durkin, M E; Amano, S; Burgeson, R E; Engvall, E; Albrechtsen, R; Virtanen, I 1997-01-01 to the laminin beta 2 chain. We found that laminin beta 1 chain was detected at all times during development from 10 weeks of gestation. Laminin beta 2 chain was first detected in 15 to 22-week-old fetal skeletal muscle as distinct focal immunoreactivity in the sarcolemmal basement membrane area of...... some myofibers. In the adult skeletal muscle, laminin beta 2 chain immunoreactivity was found along the entire perimeter of each of the individual myofibers in a large series of different muscles studied. Laminin beta 2 chain was similarly found in the skeletal muscle basement membranes in patients......We have investigated the distribution of the laminin beta 2 chain (previously s-laminin) in human fetal and adult skeletal muscle and compared it to the distribution of laminin beta 1. Immunoblotting and transfection assays were used to characterize a panel of monoclonal and polyclonal antibodies... 7. Diethylstilbestrol alters positive and negative selection of T cells in the thymus and modulates T-cell repertoire in the periphery International Nuclear Information System (INIS) Prenatal exposure to diethylstilbestrol (DES) is known to cause altered immune functions and increased susceptibility to autoimmune disease in humans. In the current study, we investigated the effects of DES on T-cell differentiation in the thymus using the HY-TCR transgenic (Tg) mouse model in which the female mice exhibit positive selection of T cells bearing the Tg TCR, while the male mice show negative selection of such T cells. In female HY-TCR-Tg mice, exposure to DES showed more pronounced decrease in thymic cellularity when compared to male mice. Additionally, female mice also showed a significant decrease in the proportion of double-positive (DP) T cells in the thymus and HY-TCR-specific CD8+ T cells in the periphery. Male mice exhibiting negative selection also showed decreased thymic cellularity following DES exposure. Moreover, the male mice showed increased proportion of double-negative (DN) T cells in the thymus and decreased proportion of CD8+ T cells. The density of expression of HY-TCR on CD8+ cells was increased following DES exposure in both females and males. Finally, the proliferative response of thymocytes to mitogens and peripheral lymph node T cells to male H-Y antigen was significantly altered in female and male mice following DES treatment. Taken together, these data suggest that DES alters T-cell differentiation in the thymus by interfering with positive and negative selection processes, which in turn modulates the T-cell repertoire in the periphery 8. Effects of dexamethasone on proliferation, differentiation and apoptosis of adult human osteoblasts in vitro Institute of Scientific and Technical Information of China (English) 杨林; 陶天遵; 王新婷; 杜宁; 陈伟珍; 陶树清; 王志成; 吴丽萍 2003-01-01 Objective To observe the effects of dexamethasone on proliferation, differentiation and apoptosis of adult human osteoblasts in vitro. Methods Iliac trabecular bone specimens were obtained from adult patients undergoing necessary surgery. After the bone pieces were digested with collagenase-trypsin, osteoblasts were released and incubated at 37℃ in a relative humidity of 95% and 5% CO2. Then, the cells were purified, and their passages were given DMEM-F12 and fetal bovine serum medium. Subsequently, 10-8 mol/L dexamethasone was added into the culture medium to incubate the osteoblasts for three days, and the cells from control groups were incubated without any drugs. All cells were observed continually with phase contrast microscope and transmission electron microscope. Finally, apoptosis was detected by the use of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) and biochemical indices, alkaline phosphatase (ALP) and osteocalcin (OCN) were used to determine the effects of dexamethasone on proliferation, differentiation and apoptosis of adult osteoblasts in vitro. Results In the adult osteoblasts obtained by collagenase-trypsin digestion, it achieved high survial, stable biochemical indices and excellent purification. Under the condition of dexamethasone 10-8 mol/L and osteoblasts 10 000/ml, there was significant promotion of ALP and OCN secretion without cell apoptosis.Conclusions Dexamethasone has a significant effect on the proliferation and differentiation of adult osteoblasts in vitro without apoptosis, and dexamethasone at the suggested concentration can be used as positive control in drug studies for osteoporosis treatment. 9. Inventory of Research on Adult Human Resource Development in Canada. Inventaire de la Recherche sur le Developpement des Ressources Humaines Adultes au Canada. Science.gov (United States) Page, Garnet T.; Caldwell, George This bilingual directory of research (1963-68) in the development of adult human resources in Canada indicates types of projects undertaken, principal objectives, institutions involved, amounts and sources of funding. It also shows which areas of research have been well covered, those with little or no coverage, and those which might be given a… 10. Naïve adult stem cells isolation from primary human fibroblast cultures. Science.gov (United States) Wenzel, Vera; Roedl, Daniela; Ring, Johannes; Djabali, Karima 2013-01-01 Over the last decade, several adult stem cell populations have been identified in human skin (1-4). The isolation of multipotent adult dermal precursors was first reported by Miller F. D laboratory (5, 6). These early studies described a multipotent precursor cell population from adult mammalian dermis (5). These cells--termed SKPs, for skin-derived precursors-- were isolated and expanded from rodent and human skin and differentiated into both neural and mesodermal progeny, including cell types never found in skin, such as neurons (5). Immunocytochemical studies on cultured SKPs revealed that cells expressed vimentin and nestin, an intermediate filament protein expressed in neural and skeletal muscle precursors, in addition to fibronectin and multipotent stem cell markers (6). Until now, the adult stem cells population SKPs have been isolated from freshly collected mammalian skin biopsies. Recently, we have established and reported that a population of skin derived precursor cells could remain present in primary fibroblast cultures established from skin biopsies (7). The assumption that a few somatic stem cells might reside in primary fibroblast cultures at early population doublings was based upon the following observations: (1) SKPs and primary fibroblast cultures are derived from the dermis, and therefore a small number of SKP cells could remain present in primary dermal fibroblast cultures and (2) primary fibroblast cultures grown from frozen aliquots that have been subjected to unfavorable temperature during storage or transfer contained a small number of cells that remained viable (7). These rare cells were able to expand and could be passaged several times. This observation suggested that a small number of cells with high proliferation potency and resistance to stress were present in human fibroblast cultures (7). We took advantage of these findings to establish a protocol for rapid isolation of adult stem cells from primary fibroblast cultures that are 11. Epithelial cells with hepatobiliary phenotype: Is it another stem cell candidate for healthy adult human liver? Institute of Scientific and Technical Information of China (English) Dung Ngoc Khuu; Mustapha Najimi; Etienne M Sokal 2007-01-01 AIM: To investigate the presence and role of liver epithelial cells in the healthy human adult liver.METHODS: Fifteen days after human hepatocyte primary culture, epithelial like cells emerged and started proliferating. Cell colonies were isolated and sub-cultured for more than 160 d under specific culture conditions. Cells were analyzed for each passage using immunofluorescence, flow cytometry and reverse transcriptionpolymerase chain reaction (RT-PCR).RESULTS: Flow cytometry analysis demonstrated that liver epithelial cells expressed common markers for hepatic and stem cells such as CD90, CD44 and CD29 but were negative for CD34 and CD117. Using immunofluorescence we demonstrated that liver epithelial cells expressed not only immature (a-fetoprotein) but also differentiated hepatocyte (albumin and CK-18) and biliary markers (CK-7 and 19), whereas they were negative for OV-6. RT-PCR analysis confirmed immunofluorescence data and revealed that liver epithelial cells did not express mature hepatocyte markers such as CYP2B6, CYP3A4 and tyrosine amino-transferase. Purified liver epithelial cells were transplanted into SCID mice. One month after transplantation, albumin positive cell foci were detected in the recipient mouse parenchyma.CONCLUSION: According to their immature and bipotential phenotype, liver epithelial cells might represent a pool of precursors in the healthy human adult liver other than oval cells. 12. Supercritical CO2 extraction of essential oils from Thymus vulgaris Directory of Open Access Journals (Sweden) S.A.B. Vieira de Melo 2000-09-01 Full Text Available Supercritical CO2 extraction of essential oil from Thymus vulgaris leaves was studied using experimental data recently obtained in the Florys S.p.A. laboratory. Mass transfer coefficients in the supercritical and solid phases from extraction curves at 40°C and 20 MPa were evaluated using a mathematical model based on the local adsorption equilibrium of essential oil on lipid in leaves. The adsorption equilibrium constant was fitted to these experimental data, and internal and external mass transfer resistances were calculated, allowing identification of the mechanism controlling the extraction process. 13. Computer tomographic examination of the thymus. Normal and pathological findings Energy Technology Data Exchange (ETDEWEB) Weiss, C.; Dinkel, E.; Wimmer, B.; Grosser, G.; Schildge, J. 1987-09-01 The diagnostic value of CT in follicular thymic hyperplasia and in thymomas in 8 patients with myasthenia gravis and in 12 patients without myasthenia gravis suffering from thymic tumors was evaluated by correlating CT-findings to surgical results and pathological-histological findings. Thymic size of the six patients with histologically proven follicular hyperplasia were scattered within the normal range, but half of them were at the upper limit. Thymic tumors were differentiated between invasive and non invasive tumors by CT staging. Solid tumors with different histology could not be further classified; the attenuation values ranging from 15-55 HU were the same in tumors, follicular hyperplasia and normal thymus. 14. Expression pattern of thymosin beta 4 in the adult human liver Directory of Open Access Journals (Sweden) S. Nemolato 2011-09-01 Full Text Available Thymosin beta-4 (Tβ4 is a member of beta-thymosins, a family of small peptides involved in polymerization of G-actin, and in many critical biological processes including apoptosis, cell migration, angiogenesis, and fibrosis. Previous studies in the newborn liver did not reveal any significant reactivity for Tβ4 during the intrauterine life. The aim of the present study was to investigate by immunohistochemistry Tβ4 expression in the adult normal liver. Thirty-five human liver samples, including 11 needle liver biopsies and 24 liver specimens obtained at autopsy, in which no pathological change was detected at the histological examination, were immunostained utilizing an anti-Tβ4 commercial antibody. Tβ4 was detected in the hepatocytes of all adult normal livers examined. A zonation of Tβ4 expression was evident in the vast majority of cases. Immunostaining was preferentially detected in zone 3, while a minor degree of reactivity was detected in periportal hepatocytes (zone 1. At higher power, Tβ4-reactive granules appeared mainly localized at the biliary pole of hepatocytes. In cases with a strong immunostaining, even perinuclear areas and the sinusoidal pole of hepatocytes appeared interested by immunoreactivity for Tβ4. The current work first evidences a strong diffuse expression of Tβ4 in the adult human liver, and adds hepatocytes to the list of human cells able to synthesize large amounts of Tβ4 in adulthood. Moreover, Tβ4 should be added to the liver proteins characterized by a zonate expression pattern, in a descending gradient from the terminal vein to the periportal areas of the liver acinus. Identifying the intimate role played by this peptide intracellularly and extracellularly, in physiology and in different liver diseases, is a major challenge for future research focusing on Tβ4. 15. Interaction involving the thymus and the hypothalamus-pituitary axis, immunomodulation by hormones Directory of Open Access Journals (Sweden) Marković Ljiljana 2 2004-01-01 production of pituitary hormones, as well as the expression of their respective receptors by thymic cell [7-9]. The influence of gonadectomy on the humoral immunity has been controversial. All investigations agree that women have higher titres of all classes of circulating antibodies than men [1, 3]. The application of estrogens stimulated the formation of antibodies in the circulation [17]. Then, if there were no sex glands, the immune response of the individual would be enhanced. Both the cellular and the humoral immune response is more powerful in the adult normal women than in men of the same age. The immune response is different in different sexes meaning that there is a sexual dimorphism. This difference has not been noted before the puberty [4]. It has been noticed that the substitution therapy has alleviated the late skin hypersensitivity [9], The estrogens have also curtailed the rejection time of the transplant and all reactions in which T-effector lymphocytes have been involved. NK-cells and T-lymphocytes activities have been decreased by the action of estrogens, as well as the release of thymus hormones [27]. Cortical RE cells express a surface antigen, gp200-MR6, which plays a significant role in thymocyte differentiation [7, 9]. irrespectively of which pathway may be triggered by neuroendocrine factors, the effects are pleiotropic and result in modulation of the expression of several genes in different cell types. Thymic neuroendocrine polypep-tides are the source of self-antigens presented by MHC molecules enabling the differentiation of haematopoietic stem cells [10]. Thymic nurse cells also produce thymosins beta 3 and beta 4 and display a neuroendocrine cell specific immunophenotype (IP: Thy-1+, A2B5+, TT+TE4+, UJ13/A+, UJ127.11+, UJ167.11+, Š181.4+ and presence of common leukocyte antigen (CLA+ [7,16]. GH enhances thymocyte release from TNCs, as well as the reconstitution of these lymphoepithelial complexes [11]. Similar to its role as a regulator of bone 16. Cervical and Anal Human Papillomavirus Infection in Adult Women in American Samoa OpenAIRE Hernandez, Brenda Y.; Ka’opua, Lana S.; Scanlan, Luana; Ah Ching, John; Kamemoto, Lori E.; Thompson, Pamela J.; Zhu, Xuemei; Shvetsov, Yurii B.; Tofaeono, Jennifer; Williams, Victor Tofaeono 2012-01-01 The prevalence of cervical and anal human papillomavirus (HPV) and risk factors associated with infections were evaluated in a cross-sectional study of 211 adult women in American Samoa. Overall, 53% of women reported ever having a Pap smear. Cervical and anal HPV was detected in 10% and 16% of women, respectively; 4% of women had concurrent cervical and anal HPV. The most common cervical genotypes were HPV 6, HPV 16, and HPV 53. Cutaneous HPV types were detected in 40% of anal infections. Ce... 17. Gastrointestinal absorption of plutonium, uranium and neptunium in fed and fasted adult baboons: Application to humans International Nuclear Information System (INIS) Gastrointestinal (GI) absorption values of plutonium, uranium, and neptunium were determined in fed and fasted adult baboons. A dual isotope method of determining GI absorption, which does not require animal sacrifice, was validated and shown to compare well with the sacrifice method (summation of oral isotope in urine with that in tissues at sacrifice). For all three elements, mean GI absorption values were significantly high (5- to 50-fold) in 24-hour (h)-fasted animals than in fed animals, and GI absorption values for baboons agreed well with those for humans 18. Extrasynaptic location of laminin beta 2 chain in developing and adult human skeletal muscle. OpenAIRE Wewer, U M; Thornell, L. E.; Loechel, F; Zhang, X.; Durkin, M. E.; Amano, S; Burgeson, R. E.; Engvall, E; Albrechtsen, R.; Virtanen, I. 1997-01-01 We have investigated the distribution of the laminin beta 2 chain (previously s-laminin) in human fetal and adult skeletal muscle and compared it to the distribution of laminin beta 1. Immunoblotting and transfection assays were used to characterize a panel of monoclonal and polyclonal antibodies to the laminin beta 2 chain. We found that laminin beta 1 chain was detected at all times during development from 10 weeks of gestation. Laminin beta 2 chain was first detected in 15 to 22-week-old f... 19. Site-specific mutagenesis of Drosophila proliferating cell nuclear antigen enhances its effects on calf thymus DNA polymerase δ Directory of Open Access Journals (Sweden) Miller Holly 2004-08-01 Full Text Available Abstract Background We and others have shown four distinct and presumably related effects of mammalian proliferating cell nuclear antigen (PCNA on DNA synthesis catalyzed by mammalian DNA polymerase δ(pol δ. In the presence of homologous PCNA, pol δ exhibits 1 increased absolute activity; 2 increased processivity of DNA synthesis; 3 stable binding of synthetic oligonucleotide template-primers (t1/2 of the pol δ•PCNA•template-primer complex ≥2.5 h; and 4 enhanced synthesis of DNA opposite and beyond template base lesions. This last effect is potentially mutagenic in vivo. Biochemical studies performed in parallel with in vivo genetic analyses, would represent an extremely powerful approach to investigate further, both DNA replication and repair in eukaryotes. Results Drosophila PCNA, although highly similar in structure to mammalian PCNA (e.g., it is >70% identical to human PCNA in amino acid sequence, can only substitute poorly for either calf thymus or human PCNA (~10% as well in affecting calf thymus pol δ. However, by mutating one or only a few amino acids in the region of Drosophila PCNA thought to interact with pol δ, all four effects can be enhanced dramatically. Conclusions Our results therefore suggest that all four above effects depend at least in part on the PCNA-pol δ interaction. Moreover unlike mammals, Drosophila offers the potential for immediate in vivo genetic analyses. Although it has proven difficult to obtain sufficient amounts of homologous pol δ for parallel in vitro biochemical studies, by altering Drosophila PCNA using site-directed mutagenesis as suggested by our results, in vitro biochemical studies may now be performed using human and/or calf thymus pol δ preparations. 20. Selection of apoptotic cell specific human antibodies from adult bone marrow. Directory of Open Access Journals (Sweden) Caroline Grönwall Full Text Available Autoreactive antibodies that recognize neo-determinants on apoptotic cells in mice have been proposed to have protective, homeostatic and immunoregulatory properties, although our knowledge about the equivalent antibodies in humans has been much more limited. In the current study, human monoclonal antibodies with binding specificity for apoptotic cells were isolated from the bone marrow of healthy adults using phage display technology. These antibodies were shown to recognize phosphorylcholine (PC-associated neo-determinants. Interestingly, three of the four identified apoptotic cell-specific antibody clones were encoded by VH3 region rearrangements with germline or nearly germline configuration without evidence of somatic hypermutation. Importantly, the different identified antibody clones had diverse heavy chain CDR3 and deduced binding surfaces as suggested by structure modeling. This may suggest a potentially great heterogeneity in human antibodies recognizing PC-related epitopes on apoptotic cells. To re-construct the postulated structural format of the parental anti-PC antibody, the dominant clone was also expressed as a recombinant human polymeric IgM, which revealed a substantially increased binding reactivity, with dose-dependent and antigen-inhibitable binding of apoptotic cells. Our findings may have implication for improved prognostic testing and therapeutic interventions in human inflammatory disease. 1. Telomere length in human adults and high level natural background radiation. Directory of Open Access Journals (Sweden) Birajalaxmi Das Full Text Available BACKGROUND: Telomere length is considered as a biomarker of aging, stress, cancer. It has been associated with many chronic diseases such as hypertension and diabetes. Although, telomere shortening due to ionizing radiation has been reported in vitro, no in vivo data is available on natural background radiation and its effect on telomere length. METHODOLOGY/PRINCIPAL FINDINGS: The present investigation is an attempt to determine the telomere length among human adults residing in high level natural radiation areas (HLNRA and the adjacent normal level radiation areas (NLNRA of Kerala coast in Southwest India. Genomic DNA was isolated from the peripheral blood mononuclear cells of 310 individuals (HLNRA: N = 233 and NLNRA: N = 77. Telomere length was determined using real time q-PCR. Both telomere (T and single copy gene (S specific primers were used to calculate the relative T/S and expressed as the relative telomere length. The telomere length was determined to be 1.22+/-0.15, 1.12+/-0.15, 1.08+/-0.08, 1.12+/-0.11, respectively, among the four dose groups (5.00 mGy per year, which did not show any dose response. The results suggested that the high level natural chronic radiation did not have significant effect on telomere length among young adult population living in HLNRA, which is indicative of better repair of telomeric ends. No significant difference in telomere length was observed between male and female individuals. In the present investigation, although the determination of telomere length was studied among the adults with an age group between 18 to 40 years (mean maternal age: 26.10+/-4.49, a negative correlation was observed with respect to age. However, inter-individual variation was (0.81-1.68 was clearly observed. CONCLUSIONS/SIGNIFICANCE: In this preliminary investigation, we conclude that elevated level of natural background radiation has no significant effect on telomere length among the adult population residing in HLNRAs of 2. Reprogramming of adult human neural stem cells into induced pluripotent stem cells Institute of Scientific and Technical Information of China (English) XIE Li-qian; SUN Hua-ping; WANG Tian; TANG Hai-liang; WANG Pu; ZHU Jian-hong; YAO Zheng-wei 2013-01-01 Background Since an effective method for generating induced pluripotent stem cells (iPSCs) from human neural stem cells (hNSCs) can offer us a promising tool for studying brain diseases,here we reported direct reprogramming of adult hNSCs into iPSCs by retroviral transduction of four defined factors.Methods NSCs were successfully isolated and cultured from the hippocampus tissue of epilepsy patients.When combined with four factors (OCT3/4,SOX2,KLF4,and c-MYC),iPSCs colonies were successfully obtained.Results Morphological characterization and specific genetic expression confirmed that these hNSCs-derived iPSCs showed embryonic stem cells-like properties,which include the ability to differentiate into all three germ layers both in vitro and in vivo.Conclusion Our method would be useful for generating human iPSCs from NSCs and provide an important tool for studying neurological diseases. 3. Thymus recovery after intensive physical exercise under conditions of immunocorrection and without it. Science.gov (United States) Sapin, M R; Tkachuk, M G 2005-11-01 Exogenous antioxidants, e.g. tocopherol, prevent undesirable changes in the thymus and accelerate its recovery after intensive physical exercise. Four weeks after the end of training (swimming) the general structure of the thymus and content of LPO products in rats treated with tocopherol corresponded to the control values, in contrast to animals receiving no correction. PMID:16758627 4. Expression of nestin by neural cells in the adult rat and human brain. Directory of Open Access Journals (Sweden) Michael L Hendrickson Full Text Available Neurons and glial cells in the developing brain arise from neural progenitor cells (NPCs. Nestin, an intermediate filament protein, is thought to be expressed exclusively by NPCs in the normal brain, and is replaced by the expression of proteins specific for neurons or glia in differentiated cells. Nestin expressing NPCs are found in the adult brain in the subventricular zone (SVZ of the lateral ventricle and the subgranular zone (SGZ of the dentate gyrus. While significant attention has been paid to studying NPCs in the SVZ and SGZ in the adult brain, relatively little attention has been paid to determining whether nestin-expressing neural cells (NECs exist outside of the SVZ and SGZ. We therefore stained sections immunocytochemically from the adult rat and human brain for NECs, observed four distinct classes of these cells, and present here the first comprehensive report on these cells. Class I cells are among the smallest neural cells in the brain and are widely distributed. Class II cells are located in the walls of the aqueduct and third ventricle. Class IV cells are found throughout the forebrain and typically reside immediately adjacent to a neuron. Class III cells are observed only in the basal forebrain and closely related areas such as the hippocampus and corpus striatum. Class III cells resemble neurons structurally and co-express markers associated exclusively with neurons. Cell proliferation experiments demonstrate that Class III cells are not recently born. Instead, these cells appear to be mature neurons in the adult brain that express nestin. Neurons that express nestin are not supposed to exist in the brain at any stage of development. That these unique neurons are found only in brain regions involved in higher order cognitive function suggests that they may be remodeling their cytoskeleton in supporting the neural plasticity required for these functions. 5. Difference of Sodium Currents between Pediatric and Adult Human Atrial Myocytes: Evidence for Developmental Changes of Sodium Channels Directory of Open Access Journals (Sweden) Benzhi Cai, Xiaoqin Mu, Dongmei Gong, Shulin Jiang, Jianping Li, Qingxin Meng, Yunlong Bai, Yanju Liu, Xinyue Wang, Xueying Tan, Baofeng Yang, Yanjie Lu 2011-01-01 Full Text Available Voltage-gated calcium currents and potassium currents were shown to undergo developmental changes in postnatal human and animal cardiomocytes. However, so far, there is no evidence whether sodium currents also presented the developmental changes in postnatal human atrial cells. The aim of this study was to observe age-related changes of sodium currents between pediatric and adult atrial myocytes. Human atrial myocytes were acutely isolated and the whole-cell patch clamp technique was used to record sodium currents isolated from pediatric and adult atrial cardiomocytes. The peak amplitude of sodium currents recorded in adult atrial cells was significantly larger than that in pediatric atrial myocytes. However, there was no significant difference of the activation voltage for peak sodium currents between two kinds of atrial myocytes. The time constants for the activation and inactivation of sodium currents were smaller in adult atria than pediatric atria. The further study revealed that the voltage-dependent inactivation of sodium currents were more slow in adult atrial cardiomyocytes than pediatric atrial cells. A significant difference was also observed in the recovery process of sodium channel from inactivation. In summary, a few significant differences were demonstrated in sodium currents characteristics between pediatric and adult atrial myocytes, which indicates that sodium currents in human atria also undergo developmental changes. 6. Adult human nasal mesenchymal-like stem cells restore cochlear spiral ganglion neurons after experimental lesion. Science.gov (United States) Bas, Esperanza; Van De Water, Thomas R; Lumbreras, Vicente; Rajguru, Suhrud; Goss, Garrett; Hare, Joshua M; Goldstein, Bradley J 2014-03-01 A loss of sensory hair cells or spiral ganglion neurons from the inner ear causes deafness, affecting millions of people. Currently, there is no effective therapy to repair the inner ear sensory structures in humans. Cochlear implantation can restore input, but only if auditory neurons remain intact. Efforts to develop stem cell-based treatments for deafness have demonstrated progress, most notably utilizing embryonic-derived cells. In an effort to bypass limitations of embryonic or induced pluripotent stem cells that may impede the translation to clinical applications, we sought to utilize an alternative cell source. Here, we show that adult human mesenchymal-like stem cells (MSCs) obtained from nasal tissue can repair spiral ganglion loss in experimentally lesioned cochlear cultures from neonatal rats. Stem cells engraft into gentamicin-lesioned organotypic cultures and orchestrate the restoration of the spiral ganglion neuronal population, involving both direct neuronal differentiation and secondary effects on endogenous cells. As a physiologic assay, nasal MSC-derived cells engrafted into lesioned spiral ganglia demonstrate responses to infrared laser stimulus that are consistent with those typical of excitable cells. The addition of a pharmacologic activator of the canonical Wnt/β-catenin pathway concurrent with stem cell treatment promoted robust neuronal differentiation. The availability of an effective adult autologous cell source for inner ear tissue repair should contribute to efforts to translate cell-based strategies to the clinic. PMID:24172073 7. The Human Adult Skeletal Muscle Transcriptional Profile Reconstructed by a Novel Computational Approach Science.gov (United States) Bortoluzzi, Stefania; d'Alessi, Fabio; Romualdi, Chiara; Danieli, Gian Antonio 2000-01-01 By applying a novel software tool, information on 4080 UniGene clusters was retrieved from three adult human skeletal muscle cDNA libraries, which were selected for being neither normalized nor subtracted. Reconstruction of a transcriptional profile of the corresponding tissue was attempted by a computational approach, classifying each transcript according to its level of expression. About 25% of the transcripts accounted for about 80% of the detected transcriptional activity, whereas most genes showed a low level of expression. This in silico transcriptional profile was then compared with data obtained by a SAGE study. A fairly good agreement between the two methods was observed. About 400 genes, highly expressed in skeletal muscle or putatively skeletal muscle-specific, may represent the minimal set of genes needed to determine the tissue specificity. These genes could be used as a convenient reference to monitor major changes in the transcriptional profile of adult human skeletal muscle in response to different physiological or pathological conditions, thus providing a framework for designing DNA microarrays and initiating biological studies. PMID:10720575 8. Establishment and improvement of model of vascularized heart-thymus composite transplantation in rats Institute of Scientific and Technical Information of China (English) XIONG Hai-bo; XIA Sui-sheng; WEN Hao; HUANG Zu-fa; YE Qi-fa 2005-01-01 Objective To establish and improve the model of heart-thymus composite transplantation. Methods Vascularized both lobes of the thymus is transplanted heterotopically with the heart as a composite graft in rats.This technique was developed and assessed, and viability of the grafts was evaluated histologically. Results Donor operation costed 38. 5 ± 3. 52 min, vascular anastomosis costed 25.0 ± 3. 28 min, operating successful rate was 90%, acute rejection was observed in SD-Wistar group, viable thymus with normal microarchitecture was maintained in Wistar-Wistar group. Conclusions The improved novel technique for combined heart-thymus transplantation is a valuable method for study of the role of thymus in transplantation immunity. 9. Diagnostic potentialities of pneumomediastinography and selective phlebography in the evaluation of thymus evolution in myasthenia International Nuclear Information System (INIS) Basing on an analysis of X-ray, intraoperative and histological findings in 124 operated on patients (thymectomy) with myasthenia the authors describe potentialities of pneumomediastinography (PMG) (pheumomediastinotomography-PMTG) in the determination of its main variants (hyperplasia, involUtion, tumor). Clear knowledge of the variants of x-ray image of the normal anatomical structures of the anterior mediastinum and age peculiarities of the thymus for correct interpretation of pneumomediastinograms is necessary. The importance of selective phlebography of the thymus for differential diagnosis of thymomas and nodular indurations of the fatty tissue in the anterior mediastinum, thymomas and fatty involution of the thymus, residual thymus and zones of fibrous-adipose tissue in the mediastinum is stressed. Selective phlebography is a simple and safe method that adds to PMG (PMTG) potentialities in the evaluation of thymus evolution in myasthenia 10. Diagnostic potentialities of pneumomediastinography and selective phlebography in the evaluation of thymus evolution in myasthenia Energy Technology Data Exchange (ETDEWEB) Vasil' ev, V.N.; Bel' chikova, N.S.; Kuksinskij, V.E. (Leningradskij Inst. Usovershenstvovaniya Vrachej (USSR)) 1983-01-01 Based on an analysis of X-ray, intraoperative and histological findings in 124 operated on patients (thymectomy) with myasthenia the authors describe potentialities of pneumomediastinography (PMG) (pheumomediastinotomography-PMTG) in the determination of its main variants (hyperplasia, involution, tumor). Clear knowledge of the variants of x-ray image of the normal anatomical structures of the anterior mediastinum and age peculiarities of the thymus for correct interpretation of pneumomediastinograms is necessary. The importance of selective phlebography of the thymus for differential diagnosis of thymomas and nodular indurations of the fatty tissue in the anterior mediastinum, thymomas and fatty involution of the thymus, residual thymus and zones of fibrous-adipose tissue in the mediastinum is stressed. Selective phlebography is a simple and safe method that adds to PMG (PMTG) potentialities in the evaluation of thymus evolution in myasthenia. 11. Thymus is enlarged in children with current atopic dermatitis. A cross-sectional study DEFF Research Database (Denmark) Olesen, Anne Braae; Andersen, G.; Jeppesen, D.L.; 2005-01-01 Atopic dermatitis is a common skin disorder of unknown aetiology with peak incidence in early childhood. The disease is associated with peripheral T-cell accumulation in the skin. The thymus is a key organ of the cellular immune response early in life. We hypothesized that atopic dermatitis is...... associated with an unbalanced establishment of the peripheral T-lymphocyte system. This cross-sectional study was performed to compare thymus sizes in patients with atopic dermatitis and healthy controls. Thirty-seven children with current atopic dermatitis were enrolled and compared with 29 healthy controls....... An interview and medical examination were performed by one doctor, an ultrasound scan was performed within 3 days of the examination, and the thymus index, a marker of thymus size, was measured. The thymus index was on average 32% higher (95% CI 3%-67%) in children with active atopic dermatitis... 12. High individual consistency in fear of humans throughout the adult lifespan of rural and urban burrowing owls Science.gov (United States) Carrete, Martina; Tella, José L. 2013-12-01 Human-induced rapid environmental changes challenge individuals by creating evolutionarily novel scenarios, where species encounter novel enemies, the new species sometimes being humans themselves. However, little is known about how individuals react to human presence, specifically whether they are able to habituate to human presence, as frequently assumed, or are selected based on their fear of humans. We tested whether fear of humans (measured as flight initiation distance in a diurnal owl) is reduced through habituation to human presence (plasticity) or whether it remains unchanged throughout the individuals' life. Results show an unusually high level of individual consistency in fear of humans throughout the adult lifespan of both rural (r = 0.96) and urban (r = 0.90) birds, lending no support to habituation. Further research should assess the role of inter-individual variability in fear of humans in shaping the distribution of individuals and species in an increasingly humanized world. 13. Characterization of pancreatic stem cells derived from adult human pancreas ducts by fluorescence activated cell sorting Institute of Scientific and Technical Information of China (English) Han-Tso Lin; Shih-Hwa Chiou; Chung-Lan Kao; Yi-Ming Shyr; Chien-Jen Hsu; Yih-Wen Tarng; Larry L-T Ho; Ching-Fai Kwok; Hung-Hai Ku 2006-01-01 AIM: To isolate putative pancreatic stem cells (PSCs)from human adult tissues of pancreas duct using serumfree, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cytometry. The potential for pancreatic lineage and the capability of β-cell differentiation in these PSCs were evaluated as well.METHODS: By using serum-free medium supplemented with essential growth factors, we attempted to isolate the putative PSCs which has been reported to express nestin and pdx-1. The MatrigelTM was employed to evaluate the differential capacity of isolated cells. Dithizone staining, insulin content/secretion measurement, and immunohistochemistry staining were used to monitor the differentiation. Fluorescence activated cell sorting (FACS)was used to detect the phenotypic markers of putative PSCs.RESULTS: A monolayer of spindle-like cells was cultivated. The putative PSCs expressed pdx-1 and nestin.They were also able to differentiate into insulin-, glucagon-, and somatostatin-positive cells. The spectrum of phenotypic markers in PSCs was investigated; a similarity was revealed when using human bone marrow-derived stem cells as the comparative experiment, such as CD29,CD44, CD49, CD50, CD51, CD62E, PDGFR-α, CD73 (SH2),CD81, CD105(SH3).CONCLUSION: In this study, we successfully isolated PSCs from adult human pancreatic duct by using serumfree medium. These PSCs not only expressed nestin and pdx-1 but also exhibited markers attributable to mesenchymal stem cells. Although work is needed to elucidate the role of these cells, the application of these PSCs might be therapeutic strategies for diabetes mellitus. 14. From the Cover: Cell-replacement therapy for diabetes: Generating functional insulin-producing tissue from adult human liver cells Science.gov (United States) Sapir, Tamar; Shternhall, Keren; Meivar-Levy, Irit; Blumenfeld, Tamar; Cohen, Hamutal; Skutelsky, Ehud; Eventov-Friedman, Smadar; Barshack, Iris; Goldberg, Iris; Pri-Chen, Sarah; Ben-Dor, Lya; Polak-Charcon, Sylvie; Karasik, Avraham; Shimon, Ilan; Mor, Eytan; Ferber, Sarah 2005-05-01 Shortage in tissue availability from cadaver donors and the need for life-long immunosuppression severely restrict the large-scale application of cell-replacement therapy for diabetic patients. This study suggests the potential use of adult human liver as alternate tissue for autologous beta-cell-replacement therapy. By using pancreatic and duodenal homeobox gene 1 (PDX-1) and soluble factors, we induced a comprehensive developmental shift of adult human liver cells into functional insulin-producing cells. PDX-1-treated human liver cells express insulin, store it in defined granules, and secrete the hormone in a glucose-regulated manner. When transplanted under the renal capsule of diabetic, immunodeficient mice, the cells ameliorated hyperglycemia for prolonged periods of time. Inducing developmental redirection of adult liver offers the potential of a cell-replacement therapy for diabetics by allowing the patient to be the donor of his own insulin-producing tissue. pancreas | transdifferentiation 15. RAPD and phytochemical analysis of Thymus moroderi plantlets after cryopreservation. Science.gov (United States) Marco-Medina, Ana; Casas, José Luis 2013-01-01 Cryopreservation is at present the most reliable strategy to preserve plant germplasm. When aromatic plants are the object of conservation it is necessary to assess not only the genetic but also the phytochemical stability to ensure that plant material maintains its qualities after storage. In this work we present molecular and phytochemical stability data related to a previously described vitrification-based cryopreservation protocol for Thymus moroderi Pau ex Martínez. RAPD markers have been used to assess the genetic stability of T. moroderi explants and revealed 0.34 percent of variation in the cryopreserved material studied. Phytochemical data collected from GC-MS analysis of dichloromethane extracts from cryopreserved plantlets rendered a profile in which 1,8-cineole (14.5 percent), camphor (5.9 percent) and borneol (5.2 percent) were the major components. Both data confirmed the suitability of the cryopreservation protocol applied. PMID:23625080 16. Parietal Bone Thickness and Vascular Diameters in Adult Modern Humans: A Survey on Cranial Remains. Science.gov (United States) Eisová, Stanislava; Rangel de Lázaro, Gizéh; Píšová, Hana; Pereira-Pedro, Sofia; Bruner, Emiliano 2016-07-01 Cranial bone thickness varies among modern humans, and many factors influencing this variability remain unclear. Growth hormones and physical activity are thought to influence the vault thickness. Considering that both systemic factors and energy supply influence the vascular system, and taking into account the structural and biomechanical interaction between endocranial vessels and vault bones, in this study we evaluate the correlation between vascular and bone diameters. In particular, we tested the relationship between the thickness of the parietal bone (which is characterized, in modern humans, by a complex vascular network) and the lumen size of the middle meningeal and diploic vessels, in adult modern humans. Our results show no patent correlation between the thickness of parietal bone and the size of the main vascular channels. Values and distributions of the branching patterns, as well as anatomical relationships between vessels and bones, are also described in order to provide information concerning the arrangement of the endocranial vascular morphology. This information is relevant in both evolutionary and medical contexts. Anat Rec, 299:888-896, 2016. © 2016 Wiley Periodicals, Inc. PMID:27072555 17. Nogo-A is a reliable oligodendroglial marker in adult human and mouse CNS and in demyelinated lesions DEFF Research Database (Denmark) Kuhlmann, Tanja; Remington, Leah; Maruschak, Brigitte; 2007-01-01 strongly expressed in mature oligodendrocytes in vivo. In the present investigation we analyzed the expression patterns of Nogo-A in adult mouse and human CNS as well as in demyelinating animal models and multiple sclerosis lesions. Nogo-A expression was compared with that of other frequently used...... oligodendroglial markers such as CC1, CNP, and in situ hybridization for proteolipid protein mRNA. Nogo-A strongly and reliably labeled oligodendrocytes in the adult CNS as well as in demyelinating lesions and thus represents a valuable tool for the identification of oligodendrocytes in human and mouse CNS tissue... 18. Cadmium content in Hypericum perforatum L. and Thymus serpyllum L. from localities of the mountains Rtanj and Ozren Directory of Open Access Journals (Sweden) Đukić-Ćosić Danijela 2011-01-01 Full Text Available Background/Aim. The beneficial effects of medicinal plants are well-known from the ancient times. However, expansion of phytopharmacy and phytotherapy occured during the last decades. Medicinal plants can absorb environmental contaminants from the ground and consequently may cause harmful effects on human health. Quality control usually comprises standard methodology which includes macroscopic identification and examination of active ingredients. Additionaly, there is a permanent need to control the level of pollutants in herbs, with a particular attention to the level of toxic metals. In this study we estimated the level of contamination by determining the content of cadmium (Cd in the herbs of Hypericum perforatum and Thymus serpyllum collected from the different localities of the mountains Rtanj and Ozren. Methods. Herbs of investigated plants were collected during July 2005 from various localities of Rtanj and Ozren mountains. After drying, homogenization and mineralization, Cd content was determined by atomic absorption spectrophotometry. Results. The obtained results show that Cd content varies significantly in Hypericum perforatum samples collected. The lowest Cd level was found in samples from the one of Rtanj localities (0.25 mg Cd/kg, while the highest was observed in Hypericum perforatum from Ozren locality (1.24 mg/kg. Levels of Cd in the three of four investigated localities were higher than pro posed by WHO (0.3 mg/kg dried herb material. In all investigated samples of Thymus serpyllum herbs Cd levels were below the limit of detection of analytical method (0.2 mg Cd/kg dried materials. Conclusion. This work contributes to the issue of Cd content in Hypericum perforatum and Thymus serpyllum grown in localities of Rtanj and Ozren, and implies the importance for systemic control of Cd content in Hypericum species in order to provide safety of their preparations. Furthermore, regarding Cd toxicity, maximal permissible level of Cd in 19. Prevalence of human norovirus and Clostridium difficile coinfections in adult hospitalized patients Science.gov (United States) Stokely, Janelle N; Niendorf, Sandra; Taube, Stefan; Hoehne, Marina; Young, Vincent B; Rogers, Mary AM; Wobus, Christiane E 2016-01-01 Objective Human norovirus (HuNoV) and Clostridium difficile are common causes of infectious gastroenteritis in adults in the US. However, limited information is available regarding HuNoV and C. difficile coinfections. Our study was designed to evaluate the prevalence of HuNoV and C. difficile coinfections among adult patients in a hospital setting and disease symptomatology. Study design and setting For a cross-sectional analysis, 384 fecal samples were tested for the presence of C. difficile toxins from patients (n=290), whom the provider suspected of C. difficile infections. Subsequent testing was then performed for HuNoV genogroups I and II. Multinomial logistic regression was performed to determine symptoms more frequently associated with coinfections. Results The final cohort consisted of the following outcome groups: C. difficile (n=196), C. difficile + HuNoV coinfection (n=40), HuNoV only (n=12), and neither (n=136). Coinfected patients were more likely to develop nausea, gas, and abdominal pain and were more likely to seek treatment in the winter season compared with individuals not infected or infected with either pathogen alone. Conclusion Our study revealed that patients with coinfection are more likely to experience certain gastrointestinal symptoms, in particular abdominal pain, suggesting an increased severity of disease symptomatology in coinfected patients. PMID:27418856 20. Differential Oxidative Stress Induced by Dengue Virus in Monocytes from Human Neonates, Adult and Elderly Individuals Science.gov (United States) Valero, Nereida; Mosquera, Jesús; Añez, Germán; Levy, Alegria; Marcucci, Rafael; de Mon, Melchor Alvarez 2013-01-01 Changes in immune response during lifespan of man are well known. These changes involve decreased neonatal and elderly immune response. In addition, it has been shown a relationship between immune and oxidative mechanisms, suggesting that altered immune response could be associated to altered oxidative response. Increased expression of nitric oxide (NO) has been documented in dengue and in monocyte cultures infected with different types of dengue virus. However, there is no information about the age-dependent NO oxidative response in humans infected by dengue virus. In this study, monocyte cultures from neonatal, elderly and adult individuals (n = 10 each group) were infected with different dengue virus types (DENV- 1 to 4) and oxidative/antioxidative responses and apoptosis were measured at days 1 and 3 of culture. Increased production of NO, lipid peroxidation and enzymatic and nonenzymatic anti-oxidative responses in dengue infected monocyte cultures were observed. However, neonatal and elderly monocytes had lower values of studied parameters when compared to those in adult-derived cultures. Apoptosis was present in infected monocytes with higher values at day 3 of culture. This reduced oxidant/antioxidant response of neonatal and elderly monocytes could be relevant in the pathogenesis of dengue disease. PMID:24069178 1. Human-figure drawing and memory functioning across the adult life span. Science.gov (United States) Ericsson, K; Winblad, B; Nilsson, L -G. 2001-03-01 The main objective was to evaluate changes in the ability to draw the human figure (HFD) across adult life span and to relate these changes to those known to exist in memory function. Healthy adults (1000) from each of 10 five-year cohorts between 35 and 80 years were recruited randomly from a population in northern Sweden. Each participant was administered a health examination including cognitive testing and a drawing test, and an extensive examination of memory functions. For the drawing variables HFDarch and HFDtot, there is a steady decrease in episodic memory with poor drawers performing at a lower level. For semantic memory up to 65 years of age, there is no difference in performance, but thereafter a decrease. Good drawers show a better memory performance than poor drawers. For priming data for both HFDarch and HFDtot, there seems to be an interaction between age and drawing, such that poor drawers perform at a lower level for the two oldest groups but not for the youngest group. The HFDess is a valuable instrument and can support clinical evaluation as a screening for cognitive decline. The reduction of essential body details was strongly related to dementia progression, and thus as good a predictor of cognitive decline as episodic memory performance. The reduced capacity to perform a complex HFD declines with age and is most pronounced in the oldest age groups. PMID:11313105 2. Early developmental gene enhancers affect subcortical volumes in the adult human brain. Science.gov (United States) Becker, Martin; Guadalupe, Tulio; Franke, Barbara; Hibar, Derrek P; Renteria, Miguel E; Stein, Jason L; Thompson, Paul M; Francks, Clyde; Vernes, Sonja C; Fisher, Simon E 2016-05-01 Genome-wide association screens aim to identify common genetic variants contributing to the phenotypic variability of complex traits, such as human height or brain morphology. The identified genetic variants are mostly within noncoding genomic regions and the biology of the genotype-phenotype association typically remains unclear. In this article, we propose a complementary targeted strategy to reveal the genetic underpinnings of variability in subcortical brain volumes, by specifically selecting genomic loci that are experimentally validated forebrain enhancers, active in early embryonic development. We hypothesized that genetic variation within these enhancers may affect the development and ultimately the structure of subcortical brain regions in adults. We tested whether variants in forebrain enhancer regions showed an overall enrichment of association with volumetric variation in subcortical structures of >13,000 healthy adults. We observed significant enrichment of genomic loci that affect the volume of the hippocampus within forebrain enhancers (empirical P = 0.0015), a finding which robustly passed the adjusted threshold for testing of multiple brain phenotypes (cutoff of P functional biology of identified associations. Hum Brain Mapp 37:1788-1800, 2016. © 2016 Wiley Periodicals, Inc. PMID:26890892 3. Micropatterning control of tubular commitment in human adult renal stem cells. Science.gov (United States) Sciancalepore, Anna G; Portone, Alberto; Moffa, Maria; Persano, Luana; De Luca, Maria; Paiano, Aurora; Sallustio, Fabio; Schena, Francesco P; Bucci, Cecilia; Pisignano, Dario 2016-07-01 The treatment of renal injury by autologous, patient-specific adult stem cells is still an unmet need. Unsolved issues remain the spatial integration of stem cells into damaged areas of the organ, the commitment in the required cell type and the development of improved bioengineered devices. In this respect, biomaterials and architectures have to be specialized to control stem cell differentiation. Here, we perform an extensive study on micropatterned extracellular matrix proteins, which constitute a simple and non-invasive approach to drive the differentiation of adult renal progenitor/stem cells (ARPCs) from human donors. ARPCs are interfaced with fibronectin (FN) micropatterns, in the absence of exogenous chemicals or cellular reprogramming. We obtain the differentiation towards tubular cells of ARPCs cultured in basal medium conditions, the tubular commitment thus being specifically induced by micropatterned substrates. We characterize the stability of the tubular differentiation as well as the induction of a polarized phenotype in micropatterned ARPCs. Thus, the developed cues, driving the functional commitment of ARPCs, offer a route to recreate the microenvironment of the stem cell niche in vitro, that may serve, in perspective, for the development of ARPC-based bioengineered devices. PMID:27105437 4. BIOEFFICACY OF ESSENTIAL OILS OF THYMUS VULGARIS AND EUGENIA CARYOPHYLLUS AGAINST HOUSEFLY, MUSCA DOMESTICA L. Directory of Open Access Journals (Sweden) J. M. CHINTALCHERE 2013-01-01 Full Text Available The housefly, Musca domestica L., is a cosmopolitan insect, associated with vectoring of various etiologicalagents. In order to search for effective control method, bioefficacy of essential oils of Thyme (Thymus vulgarisand Clove leaf (Eugenia coryophyllus was studied against housefly. The LC (50 3.18ug/cm2 value of Clove leaf oilwas found highly effective as compared to LC (50 value 4.39ug/cm2 of Thyme essential oil for inducing mortalityof M. domestica larvae. The adulticidal activity of Thyme essential oil LC (50 32.71 mg/dm3 was toxic than Cloveleaf essential oil [LC (50 53.10 mg/dm3]. In Attractant / repellant Bioassay, Thyme essential oil revealed 90.21%repellency as compared to 80.68 % value of Clove leaf essential oil against adults of House fly. In fumigationbioassay, Thyme showed high Pupicidal activity than Clove leaf oil and in contact toxicity bioassay using topicalapplication both the oils showed 100 % pupicidal mortality. The data reveals that Clove and Thyme essential oilshave excellent potential for controlling M. domestica population as eco-friendly approach in IPM. 5. Structural changes in mature rat thymus under the systematic exposure to +Gx acceleration and Glutarginum Directory of Open Access Journals (Sweden) Maxim A. Kriventsov 2013-04-01 Full Text Available Objective: Experimental work was designed primary to study morphological and functional changes in the mature rat's thymus under systematic exposure to +Gx acceleration. Secondary task is to determine a possible corrective potential of Glutarginum (L-arginine and L-glutamic acid. Methods: Mature male Wistar rats were exposed to systematic +Gx acceleration (9G, 10 min daily, 10 times. Morphology of the thymus was investigated by light and transmission electron microscopy. Results: Analysis of changes in the thymus of the mature rats under systematic exposure to +Gx acceleration showed marked structural transformation, which is characterized by a process of accidental involution and microcirculatory disturbances caused by the systematic action of gravitational forces. Such changes were potentiated by the age-related involution. Proliferation and expanding of the connective tissue structures, replacement of the parenchyma by the adipose tissue, degeneration of the epithelial component are characteristics of mature rat's thymus. At the same time, histoarchitecture of the thymus was characterized by typical stress-induced changes. Concomitant usage of Glutarginum promotes less pronounced circulatory injuries and involutive changes than in the experiments without Glutarginum treatment. Conclusion: Systematic action of +Gx acceleration causes significant alteration of normal structural organisation of the thymus of the matured rats. Using L-arginine + L-glutamate increases the adaptive capacity of the thymus. [J Exp Integr Med 2013; 3(2.000: 87-92 6. The entry of the prothymocyte into the thymus after lethal irradiation and bone marrow transplantation. 1 International Nuclear Information System (INIS) Bone marrow (BM) cells arrive in the thymus of lethally irradiated mice as early as three hours after bone marrow transplantation (BMT). They can be recognized by labelling of the injected cells with Hoechst 33342. In order to relate the immigrated BM cells to thymocyte precursor cells, direct homing and thymus repopulation experiments were compared. It was shown that homing of BM cells depends on the time between lethal irradiation and BMT, while it was previously shown that thymus repopulation does not. A cell population obtained from normal BM cells and enriched in stem cells was previously shown to repopulate the thymus similarly as BM cells from mice pretreated in vivo with 5-fluorouracil (FUBM). Both cell suspensions showed a delayed thymus repopulation when compared to normal BM. This is indicative for a depletion of prothymocytes in these cell suspensions. In the direct homing assay, however, it was found that relatively many cells from FUBM seeded into the thymus, while purified stem cells did not. These results indicate that most if not all donor cells that are present in the thymus at three hours after BMT are not thymocyte precursor cells. 21 refs.; 3 figs.; 2 tabs 7. The usefulness of MRI for detection of the thymus gland in myasthenia gravis Energy Technology Data Exchange (ETDEWEB) Hokezu, Youichi; Kaseda, Syun; Arimura, Kimiyoshi; Osame, Mitsuhiro; Baba, Kuniaki (Kagoshima Univ. (Japan). Faculty of Medicine); Ohkubo, Koichi; Hagiwara, Hiroshi 1989-08-01 Seven patients with myasthenia gravis (MG) were examined to find thymus or thymoma employing chest radiographs, computed tomography (CT), pneumomediastinography (PMG), computed tomography after pneumomediastinography (PMG-CT) and magnetic resonance imaging (MRI). X-ray CT examination could reveal thymus only in half out of 6 cases scanned. On the other hand, MRI confirmed thymus or thymoma in 6 out of 7 patients. PMG and PMG-CT confirmed thymus or thymoma clearly in all of the 4 cases studied. PMG and PMG-CT examinations revealed thymus or thymoma more clearly than MRI. MRI is, however, an examination causing no pain to the patients and also more superior to X-ray CT in distinguishing between a thymus and mediastinal fat or vascular structure. In addition, MRI could reveal even capsules in thymoma which were never revealed by X-ray CT. We concluded that MRI could be an alternative method to CT and PMG in detection of thymus or thymoma in MG. (author). 8. The usefulness of MRI for detection of the thymus gland in myasthenia gravis International Nuclear Information System (INIS) Seven patients with myasthenia gravis (MG) were examined to find thymus or thymoma employing chest radiographs, computed tomography (CT), pneumomediastinography (PMG), computed tomography after pneumomediastinography (PMG-CT) and magnetic resonance imaging (MRI). X-ray CT examination could reveal thymus only in half out of 6 cases scanned. On the other hand, MRI confirmed thymus or thymoma in 6 out of 7 patients. PMG and PMG-CT confirmed thymus or thymoma clearly in all of the 4 cases studied. PMG and PMG-CT examinations revealed thymus or thymoma more clearly than MRI. MRI is, however, an examination causing no pain to the patients and also more superior to X-ray CT in distinguishing between a thymus and mediastinal fat or vascular structure. In addition, MRI could reveal even capsules in thymoma which were never revealed by X-ray CT. We concluded that MRI could be an alternative method to CT and PMG in detection of thymus or thymoma in MG. (author) 9. Large-scale remapping of visual cortex is absent in adult humans with macular degeneration. Science.gov (United States) Baseler, Heidi A; Gouws, André; Haak, Koen V; Racey, Christopher; Crossland, Michael D; Tufail, Adnan; Rubin, Gary S; Cornelissen, Frans W; Morland, Antony B 2011-05-01 The occipital lobe contains retinotopic representations of the visual field. The representation of the central retina in early visual areas (V1-3) is found at the occipital pole. When the central retina is lesioned in both eyes by macular degeneration, this region of visual cortex at the occipital pole is accordingly deprived of input. However, even when such lesions occur in adulthood, some visually driven activity in and around the occipital pole can be observed. It has been suggested that this activity is a result of remapping of this area so that it now responds to inputs from intact, peripheral retina. We evaluated whether or not remapping of visual cortex underlies this activity. Our functional magnetic resonance imaging results provide no evidence of remapping, questioning the contemporary view that early visual areas of the adult human brain have the capacity to reorganize extensively. PMID:21441924 10. Preliminary Study on Biological Properties of Adult Human Bone Marrow-derived Mesenchymal Stem Cells Institute of Scientific and Technical Information of China (English) WU Tao; BAI Hai; WANG Jingchang; SHI Jingyun; WANG Cunbang; LU Jihong; OU Jianfeng; WANG Qian 2006-01-01 Objective: To establish a method of culture and expansion of adult human bone marrow-derived MSCs in vitro and to explore their biological properties. Methods: Mononuclear cells were obtained from 5 mL adult human bone marrow by density gradient centrifugation with Percoll solution. Adult human MSCs were cultured in Dulbecco's Modified Eagle's Medium with low glucose (LG-DMEM) containing 10% fetal calf serum at a density of 2× 105 cell/cm2. The morphocytology was observed under phase-contrast microscope. The cell growth was measured by MTT method. The flow cytometer was performed to examine the expression of cell surface molecules and cell cycle. The ultrastructure of MSCs was observed under transmission electron microscope. The immunomodulatory functions of MSCs were measured by MTT method. The effects of MSCs on the growth of K562 cells and the dynamic change of HA, Ⅳ-C, LN concentration in the culture supernatant of MSCs was also observed. Results: The MSCs harvested in this study were homogenous population and exhibited a spindle-shaped fibroblastic morphology. The cell growth curve showed that MSCs had a strong ability of proliferation. The cells were positive for CD44,while negative for hematopoietic cell surface marker such as CD3, CD4, CD7, CD13, CD14, CD15, CD19,CD22, CD33, CD34, CD45 and HLA-DR, which was closely related to graft versus host disease. Above 90% cells of MSCs were found at G0/G1 phase. The ultrastructure of MSCs indicated that there were plenty of cytoplasmic organelles. Allogeneic peripheral blood lymphocytes proliferation was suppressed by MSCs and the inhibition ratio was 60.68% (P＜0.01). The suppressive effect was also existed in the culture supernatant of MSCs and the inhibition ratio was 9.00% (P＜0.05). When lymphocytes were stimulated by PHA, the suppression effects of the culture supernatant were even stronger and the inhibition ratio was 20.91%(P＜0.01). Compared with the cell growth curve of the K562 cells alone, the K562 11. The evidence for increased L1 activity in the site of human adult brain neurogenesis. Directory of Open Access Journals (Sweden) Alexey A Kurnosov Full Text Available Retroelement activity is a common source of polymorphisms in human genome. The mechanism whereby retroelements contribute to the intraindividual genetic heterogeneity by inserting into the DNA of somatic cells is gaining increasing attention. Brain tissues are suspected to accumulate genetic heterogeneity as a result of the retroelements somatic activity. This study aims to expand our understanding of the role retroelements play in generating somatic mosaicism of neural tissues. Whole-genome Alu and L1 profiling of genomic DNA extracted from the cerebellum, frontal cortex, subventricular zone, dentate gyrus, and the myocardium revealed hundreds of somatic insertions in each of the analyzed tissues. Interestingly, the highest concentration of such insertions was detected in the dentate gyrus-the hotspot of adult neurogenesis. Insertions of retroelements and their activity could produce genetically diverse neuronal subsets, which can be involved in hippocampal-dependent learning and memory. 12. Differentiation of adult human bone marrow mesenchymal stem cells into Schwann-like cells in vitro Institute of Scientific and Technical Information of China (English) YANG Li-ye; ZHENG Jia-kun; WANG Chao-yang; LI Wen-yu 2005-01-01 Objective: To investigate the differentiative capability of adult human bone marrow mesenchymal stem cells (BMSCs) into Schwann-like cells. Methods: Bone marrows were aspirated from healthy donors and mononuclear cells were separated by Percoll lymphocytes separation liquid (1.073 g/ml) with centrifugation, cells were cultured in DMEM/F12 (1:1) medium containing 10% fetal bovine serum (FBS), 20 ng/ml epidermal growth factor (EGF) and 20 ng/ml basic fibroblast growth factor (bFGF). Cells of passage 1 were identified with immunocytochemistry. Conclusions: Bone marrow contains the stem cells with the ability of differentiating into Schwann-like cells, which may represent an alternative stem cell sources for neural transplantation. 13. A balanced view of the cerebrospinal fluid composition and functions: Focus on adult humans. Science.gov (United States) Spector, Reynold; Robert Snodgrass, S; Johanson, Conrad E 2015-11-01 In this review, a companion piece to our recent examination of choroid plexus (CP), the organ that secretes the cerebrospinal fluid (CSF), we focus on recent information in the context of reliable older data concerning the composition and functions of adult human CSF. To accomplish this, we define CSF, examine the methodology employed in studying the CSF focusing on ideal or near ideal experiments and discuss the pros and cons of several widely used analogical descriptions of the CSF including: the CSF as the "third circulation," the CSF as a "nourishing liquor," the similarities of the CSF/choroid plexus to the glomerular filtrate/kidney and finally the CSF circulation as part of the "glymphatic system." We also consider the close interrelationship between the CSF and extracellular space of brain through gap junctions and the paucity of data suggesting that the cerebral capillaries secrete a CSF-like fluid. Recently human CSF has been shown to be in dynamic flux with heart-beat, posture and especially respiration. Functionally, the CSF provides buoyancy, nourishment (e.g., vitamins) and endogenous waste product removal for the brain by bulk flow into the venous (arachnoid villi and nerve roots) and lymphatic (nasal) systems, and by carrier-mediated reabsorptive transport systems in CP. The CSF also presents many exogenous compounds to CP for metabolism or removal, indirectly cleansing the extracellular space of brain (e.g., of xenobiotics like penicillin). The CSF also carries hormones (e.g., leptin) from blood via CP or synthesized in CP (e.g., IGF-2) to the brain. In summary the CP/CSF, the third circulation, performs many functions comparable to the kidney including nourishing the brain and contributing to a stable internal milieu for the brain. These tasks are essential to normal adult brain functioning. PMID:26247808 14. Possible association of thymus dysfunction with fading syndromes in puppies and kittens. Science.gov (United States) Roth, J A 1987-05-01 "Wasting" or "fading" syndromes are common causes of puppy and kitten mortality. Numerous infectious and toxic, metabolic, or nutritional factors could potentially be responsible for wasting and death in young animals. Evidence has been presented that infectious canine hepatitis virus infection, beta-hemolytic streptococcus infection, and feline infectious peritonitis virus infection are responsible for a significant number of deaths due to wasting syndrome. However, many cases of wasting syndrome cannot be attributed to infectious agents or other specific etiologies. The thymus gland warrants special attention when one is evaluating an animal with a wasting syndrome because it is known that, in some species, neonatal thymectomy results in wasting and death. Unfortunately, most reports describing fading syndromes in puppies and kittens do not mention the gross or histologic appearance of the thymus gland at postmortem examination. When examining the thymus gland, one must keep in mind that the thymus may be hypoplastic owing to a congenital or genetic defect in its structure and function or it may be atrophic secondary to whatever is causing the fading syndrome. If a thorough history, clinical examination, and/or postmortem examination do not reveal a cause for the fading syndrome, then defective thymus function should be considered as a possible causative or contributing factor to the fading syndrome. In these cases, therapy designed to replace or improve the defective thymus function should be considered. At least one form of wasting syndrome in puppies (immunodeficient dwarfism) has been found to respond to short-term therapy with a thymus hormone (thymosin fraction 5) or with bovine growth hormone (which is thymotropic) in limited clinical trials. It is possible that other forms of wasting or fading syndromes would also respond to therapy with thymus hormone or growth hormone. Certain thymus hormones (thymopoietin pentapeptide, thymosin alpha 1, facteur 15. Adult growth hormone (GH)-deficient patients demonstrate heterogeneity between childhood onset and adult onset before and during human GH treatment. Adult Growth Hormone Deficiency Study Group DEFF Research Database (Denmark) Attanasio, A F; Lamberts, S W; Matranga, A M; 1997-01-01 The onset of adult GH deficiency may be during either adulthood (AO) or childhood (CO), but potential differences have not previously been examined. In this study the baseline and GH therapy (12.5 micrograms/kg per day) data from CO (n = 74; mean age 29 yr) and AO (n = 99; mean age 44 yr) GH......-deficient adult patients have been compared. The first 6 months comprised randomized, double-blind treatment with GH or placebo, then all patients were GH-treated for a further 12 months. At baseline the height, body weight, body mass index, lean body mass, and waist/hip ratio of AO patients were significantly (P... 16. Human parvovirus PARV4 DNA in tissues from adult individuals: a comparison with human parvovirus B19 (B19V Directory of Open Access Journals (Sweden) Rotellini Matteo 2010-10-01 Full Text Available Abstract Background PARV4 is a new member of the Parvoviridae family not closely related to any of the known human parvoviruses. Viremia seems to be a hallmark of PARV4 infection and viral DNA persistence has been demonstrated in a few tissues. Till now, PARV4 has not been associated with any disease and its prevalence in human population has not been clearly established. This study was aimed to assess the tissue distribution and the ability to persist of PARV4 in comparison to parvovirus B19 (B19V. Results PARV4 and B19V DNA detection was carried out in various tissues of individuals without suspect of acute viral infection, by a real time PCR and a nested PCR, targeting the ORF2 and the ORF1 respectively. Low amount of PARV4 DNA was found frequently (>40% in heart and liver of adults individuals, less frequently in lungs and kidneys (23,5 and 18% respectively and was rare in bone marrow, skin and synovium samples (5,5%, 4% and 5%, respectively. By comparison, B19V DNA sequences were present in the same tissues with a higher frequency (significantly higher in myocardium, skin and bone marrow except than in liver where the frequency was the same of PARV4 DNA and in plasma samples where B19V frequency was significantly lower than that of PARV4 Conclusions The particular tropism of PARV4 for liver and heart, here emerged, suggests to focus further studies on these tissues as possible target for viral replication and on the possible role of PARV4 infection in liver and heart diseases. Neither bone marrow nor kidney seem to be a common target of viral replication. 17. Relative concentrations of serum neutralizing antibody to VP3 and VP7 proteins in adults infected with a human rotavirus. OpenAIRE Ward, R. L.; Knowlton, D R; Schiff, G M; Hoshino, Y.; Greenberg, H B 1988-01-01 Two outer capsid rotavirus proteins, VP3 and VP7, have been found to elicit neutralizing-antibody production, but the immunogenicity of these proteins during human rotavirus infection has not been determined. The relative amounts of serum neutralizing antibody against the VP3 and VP7 proteins of the CJN strain of human rotavirus were, therefore, determined in adult subjects before and after infection with this virus. Reassortant strains of rotavirus that contained the CJN gene segment for onl... 18. Efficacy and Safety of Sustained-Release Recombinant Human Growth Hormone in Korean Adults with Growth Hormone Deficiency OpenAIRE Kim, Youngsook; Hong, Jae Won; Chung, Yoon-Sok; Kim, Sung-Woon; Cho, Yong-Wook; Kim, Jin Hwa; Kim, Byung-Joon; Lee, Eun Jig 2014-01-01 Purpose The administration of recombinant human growth hormone in adults with growth hormone deficiency has been known to improve metabolic impairment and quality of life. Patients, however, have to tolerate daily injections of growth hormone. The efficacy, safety, and compliance of weekly administered sustained-release recombinant human growth hormone (SR-rhGH, Declage™) supplement in patients with growth hormone deficiency were evaluated. Materials and Methods This trial is 12-week prospect... 19. Electrophysiological Profiles of Induced Neurons Converted Directly from Adult Human Fibroblasts Indicate Incomplete Neuronal Conversion Science.gov (United States) Koppensteiner, Peter; Boehm, Stefan 2014-01-01 Abstract The direct conversion of human fibroblasts to neuronal cells, termed human induced neuronal (hiN) cells, has great potential for future clinical advances. However, previous studies have not provided an in-depth analysis of electrophysiological properties of adult fibroblast-derived hiN cultures. We have examined the electrophysiological profile of hiN cells by measuring passive and active membrane properties, as well as spontaneous and evoked neurotransmission. We found that hiN cells exhibited passive membrane properties equivalent to perinatal rodent neurons. In addition, 30% of hiN cells were incapable of action potential (AP) generation and did not exhibit rectifying membrane currents, and none of the cells displayed firing patterns of typical glutamatergic pyramidal neurons. Finally, hiN cells exhibited neither spontaneous nor evoked neurotransmission. Our results suggest that current methods used to produce hiN cells provide preparations in which cells do not achieve the cellular properties of fully mature neurons, rendering these cells inadequate to investigate pathophysiological mechanisms. PMID:25437871 20. Defining the role of common variation in the genomic and biological architecture of adult human height Science.gov (United States) Chu, Audrey Y; Estrada, Karol; Luan, Jian’an; Kutalik, Zoltán; Amin, Najaf; Buchkovich, Martin L; Croteau-Chonka, Damien C; Day, Felix R; Duan, Yanan; Fall, Tove; Fehrmann, Rudolf; Ferreira, Teresa; Jackson, Anne U; Karjalainen, Juha; Lo, Ken Sin; Locke, Adam E; Mägi, Reedik; Mihailov, Evelin; Porcu, Eleonora; Randall, Joshua C; Scherag, André; Vinkhuyzen, Anna AE; Westra, Harm-Jan; Winkler, Thomas W; Workalemahu, Tsegaselassie; Zhao, Jing Hua; Absher, Devin; Albrecht, Eva; Anderson, Denise; Baron, Jeffrey; Beekman, Marian; Demirkan, Ayse; Ehret, Georg B; Feenstra, Bjarke; Feitosa, Mary F; Fischer, Krista; Fraser, Ross M; Goel, Anuj; Gong, Jian; Justice, Anne E; Kanoni, Stavroula; Kleber, Marcus E; Kristiansson, Kati; Lim, Unhee; Lotay, Vaneet; Lui, Julian C; Mangino, Massimo; Leach, Irene Mateo; Medina-Gomez, Carolina; Nalls, Michael A; Nyholt, Dale R; Palmer, Cameron D; Pasko, Dorota; Pechlivanis, Sonali; Prokopenko, Inga; Ried, Janina S; Ripke, Stephan; Shungin, Dmitry; Stancáková, Alena; Strawbridge, Rona J; Sung, Yun Ju; Tanaka, Toshiko; Teumer, Alexander; Trompet, Stella; van der Laan, Sander W; van Setten, Jessica; Van Vliet-Ostaptchouk, Jana V; Wang, Zhaoming; Yengo, Loïc; Zhang, Weihua; Afzal, Uzma; Ärnlöv, Johan; Arscott, Gillian M; Bandinelli, Stefania; Barrett, Amy; Bellis, Claire; Bennett, Amanda J; Berne, Christian; Blüher, Matthias; Bolton, Jennifer L; Böttcher, Yvonne; Boyd, Heather A; Bruinenberg, Marcel; Buckley, Brendan M; Buyske, Steven; Caspersen, Ida H; Chines, Peter S; Clarke, Robert; Claudi-Boehm, Simone; Cooper, Matthew; Daw, E Warwick; De Jong, Pim A; Deelen, Joris; Delgado, Graciela; Denny, Josh C; Dhonukshe-Rutten, Rosalie; Dimitriou, Maria; Doney, Alex SF; Dörr, Marcus; Eklund, Niina; Eury, Elodie; Folkersen, Lasse; Garcia, Melissa E; Geller, Frank; Giedraitis, Vilmantas; Go, Alan S; Grallert, Harald; Grammer, Tanja B; Gräßler, Jürgen; Grönberg, Henrik; de Groot, Lisette C.P.G.M.; Groves, Christopher J; Haessler, Jeffrey; Hall, Per; Haller, Toomas; Hallmans, Goran; Hannemann, Anke; Hartman, Catharina A; Hassinen, Maija; Hayward, Caroline; Heard-Costa, Nancy L; Helmer, Quinta; Hemani, Gibran; Henders, Anjali K; Hillege, Hans L; Hlatky, Mark A; Hoffmann, Wolfgang; Hoffmann, Per; Holmen, Oddgeir; Houwing-Duistermaat, Jeanine J; Illig, Thomas; Isaacs, Aaron; James, Alan L; Jeff, Janina; Johansen, Berit; Johansson, Åsa; Jolley, Jennifer; Juliusdottir, Thorhildur; Junttila, Juhani; Kho, Abel N; Kinnunen, Leena; Klopp, Norman; Kocher, Thomas; Kratzer, Wolfgang; Lichtner, Peter; Lind, Lars; Lindström, Jaana; Lobbens, Stéphane; Lorentzon, Mattias; Lu, Yingchang; Lyssenko, Valeriya; Magnusson, Patrik KE; Mahajan, Anubha; Maillard, Marc; McArdle, Wendy L; McKenzie, Colin A; McLachlan, Stela; McLaren, Paul J; Menni, Cristina; Merger, Sigrun; Milani, Lili; Moayyeri, Alireza; Monda, Keri L; Morken, Mario A; Müller, Gabriele; Müller-Nurasyid, Martina; Musk, Arthur W; Narisu, Narisu; Nauck, Matthias; Nolte, Ilja M; Nöthen, Markus M; Oozageer, Laticia; Pilz, Stefan; Rayner, Nigel W; Renstrom, Frida; Robertson, Neil R; Rose, Lynda M; Roussel, Ronan; Sanna, Serena; Scharnagl, Hubert; Scholtens, Salome; Schumacher, Fredrick R; Schunkert, Heribert; Scott, Robert A; Sehmi, Joban; Seufferlein, Thomas; Shi, Jianxin; Silventoinen, Karri; Smit, Johannes H; Smith, Albert Vernon; Smolonska, Joanna; Stanton, Alice V; Stirrups, Kathleen; Stott, David J; Stringham, Heather M; Sundström, Johan; Swertz, Morris A; Syvänen, Ann-Christine; Tayo, Bamidele O; Thorleifsson, Gudmar; Tyrer, Jonathan P; van Dijk, Suzanne; van Schoor, Natasja M; van der Velde, Nathalie; van Heemst, Diana; van Oort, Floor VA; Vermeulen, Sita H; Verweij, Niek; Vonk, Judith M; Waite, Lindsay L; Waldenberger, Melanie; Wennauer, Roman; Wilkens, Lynne R; Willenborg, Christina; Wilsgaard, Tom; Wojczynski, Mary K; Wong, Andrew; Wright, Alan F; Zhang, Qunyuan; Arveiler, Dominique; Bakker, Stephan JL; Beilby, John; Bergman, Richard N; Bergmann, Sven; Biffar, Reiner; Blangero, John; Boomsma, Dorret I; Bornstein, Stefan R; Bovet, Pascal; Brambilla, Paolo; Brown, Morris J; Campbell, Harry; Caulfield, Mark J; Chakravarti, Aravinda; Collins, Rory; Collins, Francis S; Crawford, Dana C; Cupples, L Adrienne; Danesh, John; de Faire, Ulf; den Ruijter, Hester M; Erbel, Raimund; Erdmann, Jeanette; Eriksson, Johan G; Farrall, Martin; Ferrannini, Ele; Ferrières, Jean; Ford, Ian; Forouhi, Nita G; Forrester, Terrence; Gansevoort, Ron T; Gejman, Pablo V; Gieger, Christian; Golay, Alain; Gottesman, Omri; Gudnason, Vilmundur; Gyllensten, Ulf; Haas, David W; Hall, Alistair S; Harris, Tamara B; Hattersley, Andrew T; Heath, Andrew C; Hengstenberg, Christian; Hicks, Andrew A; Hindorff, Lucia A; Hingorani, Aroon D; Hofman, Albert; Hovingh, G Kees; Humphries, Steve E; Hunt, Steven C; Hypponen, Elina; Jacobs, Kevin B; Jarvelin, Marjo-Riitta; Jousilahti, Pekka; Jula, Antti M; Kaprio, Jaakko; Kastelein, John JP; Kayser, Manfred; Kee, Frank; Keinanen-Kiukaanniemi, Sirkka M; Kiemeney, Lambertus A; Kooner, Jaspal S; Kooperberg, Charles; Koskinen, Seppo; Kovacs, Peter; Kraja, Aldi T; Kumari, Meena; Kuusisto, Johanna; Lakka, Timo A; Langenberg, Claudia; Le Marchand, Loic; Lehtimäki, Terho; Lupoli, Sara; Madden, Pamela AF; Männistö, Satu; Manunta, Paolo; Marette, André; Matise, Tara C; McKnight, Barbara; Meitinger, Thomas; Moll, Frans L; Montgomery, Grant W; Morris, Andrew D; Morris, Andrew P; Murray, Jeffrey C; Nelis, Mari; Ohlsson, Claes; Oldehinkel, Albertine J; Ong, Ken K; Ouwehand, Willem H; Pasterkamp, Gerard; Peters, Annette; Pramstaller, Peter P; Price, Jackie F; Qi, Lu; Raitakari, Olli T; Rankinen, Tuomo; Rao, DC; Rice, Treva K; Ritchie, Marylyn; Rudan, Igor; Salomaa, Veikko; Samani, Nilesh J; Saramies, Jouko; Sarzynski, Mark A; Schwarz, Peter EH; Sebert, Sylvain; Sever, Peter; Shuldiner, Alan R; Sinisalo, Juha; Steinthorsdottir, Valgerdur; Stolk, Ronald P; Tardif, Jean-Claude; Tönjes, Anke; Tremblay, Angelo; Tremoli, Elena; Virtamo, Jarmo; Vohl, Marie-Claude; Amouyel, Philippe; Asselbergs, Folkert W; Assimes, Themistocles L; Bochud, Murielle; Boehm, Bernhard O; Boerwinkle, Eric; Bottinger, Erwin P; Bouchard, Claude; Cauchi, Stéphane; Chambers, John C; Chanock, Stephen J; Cooper, Richard S; de Bakker, Paul IW; Dedoussis, George; Ferrucci, Luigi; Franks, Paul W; Froguel, Philippe; Groop, Leif C; Haiman, Christopher A; Hamsten, Anders; Hayes, M Geoffrey; Hui, Jennie; Hunter, David J.; Hveem, Kristian; Jukema, J Wouter; Kaplan, Robert C; Kivimaki, Mika; Kuh, Diana; Laakso, Markku; Liu, Yongmei; Martin, Nicholas G; März, Winfried; Melbye, Mads; Moebus, Susanne; Munroe, Patricia B; Njølstad, Inger; Oostra, Ben A; Palmer, Colin NA; Pedersen, Nancy L; Perola, Markus; Pérusse, Louis; Peters, Ulrike; Powell, Joseph E; Power, Chris; Quertermous, Thomas; Rauramaa, Rainer; Reinmaa, Eva; Ridker, Paul M; Rivadeneira, Fernando; Rotter, Jerome I; Saaristo, Timo E; Saleheen, Danish; Schlessinger, David; Slagboom, P Eline; Snieder, Harold; Spector, Tim D; Strauch, Konstantin; Stumvoll, Michael; Tuomilehto, Jaakko; Uusitupa, Matti; van der Harst, Pim; Völzke, Henry; Walker, Mark; Wareham, Nicholas J; Watkins, Hugh; Wichmann, H-Erich; Wilson, James F; Zanen, Pieter; Deloukas, Panos; Heid, Iris M; Lindgren, Cecilia M; Mohlke, Karen L; Speliotes, Elizabeth K; Thorsteinsdottir, Unnur; Barroso, Inês; Fox, Caroline S; North, Kari E; Strachan, David P; Beckmann, Jacques S.; Berndt, Sonja I; Boehnke, Michael; Borecki, Ingrid B; McCarthy, Mark I; Metspalu, Andres; Stefansson, Kari; Uitterlinden, André G; van Duijn, Cornelia M; Franke, Lude; Willer, Cristen J; Price, Alkes L.; Lettre, Guillaume; Loos, Ruth JF; Weedon, Michael N; Ingelsson, Erik; O’Connell, Jeffrey R; Abecasis, Goncalo R; Chasman, Daniel I; Goddard, Michael E 2014-01-01 Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explain one-fifth of heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ~2,000, ~3,700 and ~9,500 SNPs explained ~21%, ~24% and ~29% of phenotypic variance. Furthermore, all common variants together captured the majority (60%) of heritability. The 697 variants clustered in 423 loci enriched for genes, pathways, and tissue-types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/beta-catenin, and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants. PMID:25282103 1. Effect of the N-terminal residues on the quaternary dynamics of human adult hemoglobin Science.gov (United States) Chang, Shanyan; Mizuno, Misao; Ishikawa, Haruto; Mizutani, Yasuhisa 2016-05-01 The protein dynamics of human hemoglobin following ligand photolysis was studied by time-resolved resonance Raman spectroscopy. The time-resolved spectra of two kinds of recombinant hemoglobin expressed in Escherichia coli, normal recombinant hemoglobin and the α(V1M)/β(V1M) double mutant, were compared with those of human adult hemoglobin (HbA) purified from blood. A frequency shift of the iron-histidine stretching [ν(Fe-His)] band was observed in the time-resolved spectra of all three hemoglobin samples, indicative of tertiary and quaternary changes in the protein following photolysis. The spectral changes of the α(V1M)/β(V1M) double mutant were distinct from those of HbA in the tens of microseconds region, whereas the spectral changes of normal recombinant hemoglobin were similar to those of HbA isolated from blood. These results demonstrated that a structural change in the N-termini is involved in the second step of the quaternary structure change of hemoglobin. We discuss the implications of these results for understanding the allosteric pathway of HbA. 2. Defining the role of common variation in the genomic and biological architecture of adult human height. Science.gov (United States) Wood, Andrew R; Esko, Tonu; Yang, Jian; Vedantam, Sailaja; Pers, Tune H; Gustafsson, Stefan; Chu, Audrey Y; Estrada, Karol; Luan, Jian'an; Kutalik, Zoltán; Amin, Najaf; Buchkovich, Martin L; Croteau-Chonka, Damien C; Day, Felix R; Duan, Yanan; Fall, Tove; Fehrmann, Rudolf; Ferreira, Teresa; Jackson, Anne U; Karjalainen, Juha; Lo, Ken Sin; Locke, Adam E; Mägi, Reedik; Mihailov, Evelin; Porcu, Eleonora; Randall, Joshua C; Scherag, André; Vinkhuyzen, Anna A E; Westra, Harm-Jan; Winkler, Thomas W; Workalemahu, Tsegaselassie; Zhao, Jing Hua; Absher, Devin; Albrecht, Eva; Anderson, Denise; Baron, Jeffrey; Beekman, Marian; Demirkan, Ayse; Ehret, Georg B; Feenstra, Bjarke; Feitosa, Mary F; Fischer, Krista; Fraser, Ross M; Goel, Anuj; Gong, Jian; Justice, Anne E; Kanoni, Stavroula; Kleber, Marcus E; Kristiansson, Kati; Lim, Unhee; Lotay, Vaneet; Lui, Julian C; Mangino, Massimo; Mateo Leach, Irene; Medina-Gomez, Carolina; Nalls, Michael A; Nyholt, Dale R; Palmer, Cameron D; Pasko, Dorota; Pechlivanis, Sonali; Prokopenko, Inga; Ried, Janina S; Ripke, Stephan; Shungin, Dmitry; Stancáková, Alena; Strawbridge, Rona J; Sung, Yun Ju; Tanaka, Toshiko; Teumer, Alexander; Trompet, Stella; van der Laan, Sander W; van Setten, Jessica; Van Vliet-Ostaptchouk, Jana V; Wang, Zhaoming; Yengo, Loïc; Zhang, Weihua; Afzal, Uzma; Arnlöv, Johan; Arscott, Gillian M; Bandinelli, Stefania; Barrett, Amy; Bellis, Claire; Bennett, Amanda J; Berne, Christian; Blüher, Matthias; Bolton, Jennifer L; Böttcher, Yvonne; Boyd, Heather A; Bruinenberg, Marcel; Buckley, Brendan M; Buyske, Steven; Caspersen, Ida H; Chines, Peter S; Clarke, Robert; Claudi-Boehm, Simone; Cooper, Matthew; Daw, E Warwick; De Jong, Pim A; Deelen, Joris; Delgado, Graciela; Denny, Josh C; Dhonukshe-Rutten, Rosalie; Dimitriou, Maria; Doney, Alex S F; Dörr, Marcus; Eklund, Niina; Eury, Elodie; Folkersen, Lasse; Garcia, Melissa E; Geller, Frank; Giedraitis, Vilmantas; Go, Alan S; Grallert, Harald; Grammer, Tanja B; Gräßler, Jürgen; Grönberg, Henrik; de Groot, Lisette C P G M; Groves, Christopher J; Haessler, Jeffrey; Hall, Per; Haller, Toomas; Hallmans, Goran; Hannemann, Anke; Hartman, Catharina A; Hassinen, Maija; Hayward, Caroline; Heard-Costa, Nancy L; Helmer, Quinta; Hemani, Gibran; Henders, Anjali K; Hillege, Hans L; Hlatky, Mark A; Hoffmann, Wolfgang; Hoffmann, Per; Holmen, Oddgeir; Houwing-Duistermaat, Jeanine J; Illig, Thomas; Isaacs, Aaron; James, Alan L; Jeff, Janina; Johansen, Berit; Johansson, Åsa; Jolley, Jennifer; Juliusdottir, Thorhildur; Junttila, Juhani; Kho, Abel N; Kinnunen, Leena; Klopp, Norman; Kocher, Thomas; Kratzer, Wolfgang; Lichtner, Peter; Lind, Lars; Lindström, Jaana; Lobbens, Stéphane; Lorentzon, Mattias; Lu, Yingchang; Lyssenko, Valeriya; Magnusson, Patrik K E; Mahajan, Anubha; Maillard, Marc; McArdle, Wendy L; McKenzie, Colin A; McLachlan, Stela; McLaren, Paul J; Menni, Cristina; Merger, Sigrun; Milani, Lili; Moayyeri, Alireza; Monda, Keri L; Morken, Mario A; Müller, Gabriele; Müller-Nurasyid, Martina; Musk, Arthur W; Narisu, Narisu; Nauck, Matthias; Nolte, Ilja M; Nöthen, Markus M; Oozageer, Laticia; Pilz, Stefan; Rayner, Nigel W; Renstrom, Frida; Robertson, Neil R; Rose, Lynda M; Roussel, Ronan; Sanna, Serena; Scharnagl, Hubert; Scholtens, Salome; Schumacher, Fredrick R; Schunkert, Heribert; Scott, Robert A; Sehmi, Joban; Seufferlein, Thomas; Shi, Jianxin; Silventoinen, Karri; Smit, Johannes H; Smith, Albert Vernon; Smolonska, Joanna; Stanton, Alice V; Stirrups, Kathleen; Stott, David J; Stringham, Heather M; Sundström, Johan; Swertz, Morris A; Syvänen, Ann-Christine; Tayo, Bamidele O; Thorleifsson, Gudmar; Tyrer, Jonathan P; van Dijk, Suzanne; van Schoor, Natasja M; van der Velde, Nathalie; van Heemst, Diana; van Oort, Floor V A; Vermeulen, Sita H; Verweij, Niek; Vonk, Judith M; Waite, Lindsay L; Waldenberger, Melanie; Wennauer, Roman; Wilkens, Lynne R; Willenborg, Christina; Wilsgaard, Tom; Wojczynski, Mary K; Wong, Andrew; Wright, Alan F; Zhang, Qunyuan; Arveiler, Dominique; Bakker, Stephan J L; Beilby, John; Bergman, Richard N; Bergmann, Sven; Biffar, Reiner; Blangero, John; Boomsma, Dorret I; Bornstein, Stefan R; Bovet, Pascal; Brambilla, Paolo; Brown, Morris J; Campbell, Harry; Caulfield, Mark J; Chakravarti, Aravinda; Collins, Rory; Collins, Francis S; Crawford, Dana C; Cupples, L Adrienne; Danesh, John; de Faire, Ulf; den Ruijter, Hester M; Erbel, Raimund; Erdmann, Jeanette; Eriksson, Johan G; Farrall, Martin; Ferrannini, Ele; Ferrières, Jean; Ford, Ian; Forouhi, Nita G; Forrester, Terrence; Gansevoort, Ron T; Gejman, Pablo V; Gieger, Christian; Golay, Alain; Gottesman, Omri; Gudnason, Vilmundur; Gyllensten, Ulf; Haas, David W; Hall, Alistair S; Harris, Tamara B; Hattersley, Andrew T; Heath, Andrew C; Hengstenberg, Christian; Hicks, Andrew A; Hindorff, Lucia A; Hingorani, Aroon D; Hofman, Albert; Hovingh, G Kees; Humphries, Steve E; Hunt, Steven C; Hypponen, Elina; Jacobs, Kevin B; Jarvelin, Marjo-Riitta; Jousilahti, Pekka; Jula, Antti M; Kaprio, Jaakko; Kastelein, John J P; Kayser, Manfred; Kee, Frank; Keinanen-Kiukaanniemi, Sirkka M; Kiemeney, Lambertus A; Kooner, Jaspal S; Kooperberg, Charles; Koskinen, Seppo; Kovacs, Peter; Kraja, Aldi T; Kumari, Meena; Kuusisto, Johanna; Lakka, Timo A; Langenberg, Claudia; Le Marchand, Loic; Lehtimäki, Terho; Lupoli, Sara; Madden, Pamela A F; Männistö, Satu; Manunta, Paolo; Marette, André; Matise, Tara C; McKnight, Barbara; Meitinger, Thomas; Moll, Frans L; Montgomery, Grant W; Morris, Andrew D; Morris, Andrew P; Murray, Jeffrey C; Nelis, Mari; Ohlsson, Claes; Oldehinkel, Albertine J; Ong, Ken K; Ouwehand, Willem H; Pasterkamp, Gerard; Peters, Annette; Pramstaller, Peter P; Price, Jackie F; Qi, Lu; Raitakari, Olli T; Rankinen, Tuomo; Rao, D C; Rice, Treva K; Ritchie, Marylyn; Rudan, Igor; Salomaa, Veikko; Samani, Nilesh J; Saramies, Jouko; Sarzynski, Mark A; Schwarz, Peter E H; Sebert, Sylvain; Sever, Peter; Shuldiner, Alan R; Sinisalo, Juha; Steinthorsdottir, Valgerdur; Stolk, Ronald P; Tardif, Jean-Claude; Tönjes, Anke; Tremblay, Angelo; Tremoli, Elena; Virtamo, Jarmo; Vohl, Marie-Claude; Amouyel, Philippe; Asselbergs, Folkert W; Assimes, Themistocles L; Bochud, Murielle; Boehm, Bernhard O; Boerwinkle, Eric; Bottinger, Erwin P; Bouchard, Claude; Cauchi, Stéphane; Chambers, John C; Chanock, Stephen J; Cooper, Richard S; de Bakker, Paul I W; Dedoussis, George; Ferrucci, Luigi; Franks, Paul W; Froguel, Philippe; Groop, Leif C; Haiman, Christopher A; Hamsten, Anders; Hayes, M Geoffrey; Hui, Jennie; Hunter, David J; Hveem, Kristian; Jukema, J Wouter; Kaplan, Robert C; Kivimaki, Mika; Kuh, Diana; Laakso, Markku; Liu, Yongmei; Martin, Nicholas G; März, Winfried; Melbye, Mads; Moebus, Susanne; Munroe, Patricia B; Njølstad, Inger; Oostra, Ben A; Palmer, Colin N A; Pedersen, Nancy L; Perola, Markus; Pérusse, Louis; Peters, Ulrike; Powell, Joseph E; Power, Chris; Quertermous, Thomas; Rauramaa, Rainer; Reinmaa, Eva; Ridker, Paul M; Rivadeneira, Fernando; Rotter, Jerome I; Saaristo, Timo E; Saleheen, Danish; Schlessinger, David; Slagboom, P Eline; Snieder, Harold; Spector, Tim D; Strauch, Konstantin; Stumvoll, Michael; Tuomilehto, Jaakko; Uusitupa, Matti; van der Harst, Pim; Völzke, Henry; Walker, Mark; Wareham, Nicholas J; Watkins, Hugh; Wichmann, H-Erich; Wilson, James F; Zanen, Pieter; Deloukas, Panos; Heid, Iris M; Lindgren, Cecilia M; Mohlke, Karen L; Speliotes, Elizabeth K; Thorsteinsdottir, Unnur; Barroso, Inês; Fox, Caroline S; North, Kari E; Strachan, David P; Beckmann, Jacques S; Berndt, Sonja I; Boehnke, Michael; Borecki, Ingrid B; McCarthy, Mark I; Metspalu, Andres; Stefansson, Kari; Uitterlinden, André G; van Duijn, Cornelia M; Franke, Lude; Willer, Cristen J; Price, Alkes L; Lettre, Guillaume; Loos, Ruth J F; Weedon, Michael N; Ingelsson, Erik; O'Connell, Jeffrey R; Abecasis, Goncalo R; Chasman, Daniel I; Goddard, Michael E; Visscher, Peter M; Hirschhorn, Joel N; Frayling, Timothy M 2014-11-01 Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ∼2,000, ∼3,700 and ∼9,500 SNPs explained ∼21%, ∼24% and ∼29% of phenotypic variance. Furthermore, all common variants together captured 60% of heritability. The 697 variants clustered in 423 loci were enriched for genes, pathways and tissue types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/β-catenin and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants. PMID:25282103 3. Helicobacter pylori Eradication Causes Perturbation of the Human Gut Microbiome in Young Adults. Directory of Open Access Journals (Sweden) Theresa Wan-Chen Yap Full Text Available Accumulating evidence shows that Helicobacter pylori protects against some metabolic and immunological diseases in which the development of these diseases coincide with temporal or permanent dysbiosis. The aim of this study was to assess the effect of H. pylori eradication on the human gut microbiome.As part of the currently on-going ESSAY (Eradication Study in Stable Adults/Youths study, we collected stool samples from 17 H. pylori-positive young adult (18-30 years-old volunteers. The same cohort was followed up 6, 12 and 18 months-post H. pylori eradication. The impact of H. pylori on the human gut microbiome pre- and post-eradication was investigated using high throughput 16S rRNA gene (V3-V4 region sequencing using the Illumina Miseq followed by data analysis using Qiime pipeline.We compared the composition and diversity of bacterial communities in the fecal microbiome of the H. pylori-positive volunteers, before and after H. pylori eradication therapy. The 16S rRNA gene was sequenced at an average of 150,000-170,000 reads/sample. The microbial diversity were similar pre- and post-H. pylori eradication with no significant differences in richness and evenness of bacterial species. Despite that the general profile of the gut microbiome was similar pre- and post-eradication, some changes in the bacterial communities at the phylum and genus levels were notable, particularly the decrease in relative abundance of Bacterioidetes and corresponding increase in Firmicutes after H. pylori eradication. The significant increase of short-chain fatty acids (SCFA-producing bacteria genera could also be associated with increased risk of metabolic disorders.Our preliminary stool metagenomics study shows that eradication of H. pylori caused perturbation of the gut microbiome and may indirectly affect the health of human. Clinicians should be aware of the effect of broad spectrum antibiotics used in H. pylori eradication regimen and be cautious in the clinical 4. Helicobacter pylori Eradication Causes Perturbation of the Human Gut Microbiome in Young Adults Science.gov (United States) Yap, Theresa Wan-Chen; Gan, Han-Ming; Lee, Yin-Peng; Leow, Alex Hwong-Ruey; Azmi, Ahmad Najib; Francois, Fritz; Perez-Perez, Guillermo I.; Loke, Mun-Fai; Goh, Khean-Lee; Vadivelu, Jamuna 2016-01-01 Background Accumulating evidence shows that Helicobacter pylori protects against some metabolic and immunological diseases in which the development of these diseases coincide with temporal or permanent dysbiosis. The aim of this study was to assess the effect of H. pylori eradication on the human gut microbiome. Methods As part of the currently on-going ESSAY (Eradication Study in Stable Adults/Youths) study, we collected stool samples from 17 H. pylori-positive young adult (18–30 years-old) volunteers. The same cohort was followed up 6, 12 and 18 months-post H. pylori eradication. The impact of H. pylori on the human gut microbiome pre- and post-eradication was investigated using high throughput 16S rRNA gene (V3-V4 region) sequencing using the Illumina Miseq followed by data analysis using Qiime pipeline. Results We compared the composition and diversity of bacterial communities in the fecal microbiome of the H. pylori-positive volunteers, before and after H. pylori eradication therapy. The 16S rRNA gene was sequenced at an average of 150,000–170,000 reads/sample. The microbial diversity were similar pre- and post-H. pylori eradication with no significant differences in richness and evenness of bacterial species. Despite that the general profile of the gut microbiome was similar pre- and post-eradication, some changes in the bacterial communities at the phylum and genus levels were notable, particularly the decrease in relative abundance of Bacterioidetes and corresponding increase in Firmicutes after H. pylori eradication. The significant increase of short-chain fatty acids (SCFA)-producing bacteria genera could also be associated with increased risk of metabolic disorders. Conclusions Our preliminary stool metagenomics study shows that eradication of H. pylori caused perturbation of the gut microbiome and may indirectly affect the health of human. Clinicians should be aware of the effect of broad spectrum antibiotics used in H. pylori eradication regimen 5. GH safety workshop position paper: A critical appraisal of recombinant human GH therapy in children and adults Science.gov (United States) Recombinant human Growth Hormone (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that 'for approved indications, GH is safe'; however, t... 6. The Model Human Processor and the Older Adult: Parameter Estimation and Validation within a Mobile Phone Task Science.gov (United States) Jastrzembski, Tiffany S.; Charness, Neil 2007-01-01 The authors estimate weighted mean values for nine information processing parameters for older adults using the Card, Moran, and Newell (1983) Model Human Processor model. The authors validate a subset of these parameters by modeling two mobile phone tasks using two different phones and comparing model predictions to a sample of younger (N = 20;… 7. TP53 mutation and human papilloma virus status of oral squamous cell carcinomas in young adult patients NARCIS (Netherlands) B.J.M. Braakhuis; M.M. Rietbergen; M. Buijze; P.J.F. Snijders; E. Bloemena; R.H. Brakenhoff; C.R. Leemans 2014-01-01 Objective Little is known about the molecular carcinogenesis of oral squamous cell carcinoma (OSCC) in young adult patients. The aim of this study was to investigate the detailed TP53 mutation and human papilloma virus (HPV) status of OSCC in patients, younger than 45 years. Methods TP53 mutations w 8. What Happens in the Thymus Does Not Stay in the Thymus: How T Cells Recycle the CD4+-CD8+ Lineage Commitment Transcriptional Circuitry To Control Their Function. Science.gov (United States) Vacchio, Melanie S; Bosselut, Rémy 2016-06-15 MHC-restricted CD4(+) and CD8(+) T cells are at the core of most adaptive immune responses. Although these cells carry distinct functions, they arise from a common precursor during thymic differentiation, in a developmental sequence that matches CD4 and CD8 expression and functional potential with MHC restriction. Although the transcriptional control of CD4(+)-CD8(+) lineage choice in the thymus is now better understood, less was known about what maintains the CD4(+) and CD8(+) lineage integrity of mature T cells. In this review, we discuss the mechanisms that establish in the thymus, and maintain in postthymic cells, the separation of these lineages. We focus on recent studies that address the mechanisms of epigenetic control of Cd4 expression and emphasize how maintaining a transcriptional circuitry nucleated around Thpok and Runx proteins, the key architects of CD4(+)-CD8(+) lineage commitment in the thymus, is critical for CD4(+) T cell helper functions. PMID:27260768 9. Lymphocyte development in irradiated thymuses: dynamics of colonization by progenitor cells and regeneration of resident cells International Nuclear Information System (INIS) Lymphocyte development in irradiated thymuses was analyzed using two complementary strategies: an in vitro experimental model and computer simulations. In the in vitro model, fetal thymus lobes were irradiated and the regeneration of cells that survived irradiation were examined, with the results compared to those of reconstitution of the thymus by donor bone marrow cells and their competition with the thymic resident cells. In vitro measurements of resident cell kinetics showed that cell proliferation is slowed down significantly after a relatively low (10Gy) irradiation dose. Although the number of thymocytes that survived irradiation remained low for several days post-irradiation, further colonization by donor cells was not possible, unless performed within 6 h after irradiation. These experimental results, coupled with the analysis by computer simulations, suggest that bone marrow cell engraftment in the irradiated thymus may be limited by the presence of radiation-surviving thymic resident cells and the reduced availability of seeding niches. (Author) 10. Analysis of activin/TGFB-signaling modulators within the normal and dysfunctional adult human testis reveals evidence of altered signaling capacity in a subset of seminomas DEFF Research Database (Denmark) Dias, Vinali L; Rajpert-De Meyts, Ewa; McLachlan, Robert; 2009-01-01 adult human testes samples. Signaling transducers phosphorylated SMAD2/3, and signaling modulators SMAD6, MAN-1, inhibin alpha (INHA), and beta-glycan were detected in Bouins fixed, paraffin-embedded adult human testis sections using immunohistochemistry. Additional samples examined were from testicular... 11. Detection of embryonic stem cell markers in adult human adipose tissue-derived stem cells Directory of Open Access Journals (Sweden) Sarasa Bharati Arumugam 2011-01-01 Full Text Available Background: Bone marrow transplantation is already an established therapy, which is now widely used in medicine to treat leukemia, lymphoma, and several inherited blood disorders. The culture of multilineage cells from easily available adipose tissue is another source of multipotent mesenchymal stem cells, and is referred to as adipose tissue-derived stem cells (ADSCs. While ADSCs are being used to treat various conditions, some lacuna exists regarding the specific proteins in these. It was therefore decided to analyze the specific proteins of embryonic cells in ADSCs. Aims: To analyze the specific protein of embryonic stem cells (ESCs in ADSCs. Materials and Methods: Adult human adipose tissue-derived stem cells (ADSCs were harvested from 13 patients after obtaining patients′ consent. The specific markers of ESCs included surface proteins CD10, CD13, CD44, CD59, CD105, and CD166, and further nucleostemin,(NS NANOG, peroxisome proliferator-activated receptor-gγ, collagen type 1 (Coll1, alkaline phosphate, (ALP osteocalcin (OC, and core binding factor 1 (Cbfa1 were analyzed using by reverse transcription-polymerase chain reaction, (RT-PCR immunofluorescence (IF, and western blot. Results: All the proteins were expressed distinctly, except CD13 and OC. CD13 was found individually with different expressions, and OC expression was discernable. Conclusions: Although the ESC with its proven self-renewal capacity and pluripotency seems appropriate for clinical use, the recent work on ADSCs suggests that these adult stem cells would be a valuable source for future biotechnology, especially since there is a relative ease of procurement. 12. Development of human white matter fiber pathways: From newborn to adult ages. Science.gov (United States) Cohen, Andrew H; Wang, Rongpin; Wilkinson, Molly; MacDonald, Patrick; Lim, Ashley R; Takahashi, Emi 2016-05-01 Major long-range white matter pathways (cingulum, fornix, uncinate fasciculus [UF], inferior fronto-occipital fasciculus [IFOF], inferior longitudinal fasciculus [ILF], thalamocortical [TC], and corpus callosal [CC] pathways) were identified in eighty-three healthy humans ranging from newborn to adult ages. We tracked developmental changes using high-angular resolution diffusion MR tractography. Fractional anisotropy (FA), apparent diffusion coefficient, number, length, and volume were measured in pathways in each subject. Newborns had fewer, and more sparse, pathways than those of the older subjects. FA, number, length, and volume of pathways gradually increased with age and reached a plateau between 3 and 5 years of age. Data were further analyzed by normalizing with mean adult values as well as with each subject's whole brain values. Comparing subjects of 3 years old and under to those over 3 years old, the studied pathways showed differential growth patterns. The CC, bilateral cingulum, bilateral TC, and the left IFOF pathways showed significant growth both in volume and length, while the bilateral fornix, bilateral ILF and bilateral UF showed significant growth only in volume. The TC and CC took similar growth patterns with the whole brain. FA values of the cingulum and IFOF, and the length of ILF showed leftward asymmetry. The fornix, ILF and UF occupied decreased space compared to the whole brain during development with higher FA values, likely corresponding to extensive maturation of the pathways compared to the mean whole brain maturation. We believe that the outcome of this study will provide an important database for future reference. PMID:26948153 13. Morphometric Characteristics of Fetal Thymus Características morfométricas del timo fetal OpenAIRE Carmen Niurka Piña Loyola; Marta Rosa González Debén; Alfredo Quiñonez Ceballos 2012-01-01 Background: Classical medicine texts include morphological patterns such as thymus, but reported values vary. Objective: To determine morphometric parameters of the thymus and its relation to gestational age, fetal weight and sex. Methods: A prospective and descriptive study was conducted from May 2003 to May 2008 in the Dr. Gustavo Aldereguía Lima General University H... 14. Structural changes in mature rat thymus under the systematic exposure to +Gx acceleration and Glutarginum OpenAIRE Maxim A. Kriventsov; Gennady A. Moroz 2013-01-01 Objective: Experimental work was designed primary to study morphological and functional changes in the mature rat's thymus under systematic exposure to +Gx acceleration. Secondary task is to determine a possible corrective potential of Glutarginum (L-arginine and L-glutamic acid). Methods: Mature male Wistar rats were exposed to systematic +Gx acceleration (9G, 10 min daily, 10 times). Morphology of the thymus was investigated by light and transmission electron microscopy. Results: Analysis o... 15. Non-cytotoxic Thymus capitata extracts prevent Bovine herpesvirus-1 infection in cell cultures OpenAIRE Boubaker–Elandalousi, Ramzi; Mekni–Toujani, Marwa; Kaabi, Belhassen; Larbi, Imen; Diouani, Mohamed-Fethi; Gharbi, Mohamed; Akkari, Hafidh; B’chir, Fatma; Ghram, Abdeljelil 2014-01-01 Background Bovine herpes virus type 1 (BHV-1) still causes great economic loss to the livestock industry and trade because there aren’t any available drugs that proved to be fully effective against it. In this study, the cytotoxicity and the antiviral activities of the Thymus capitata extracts were evaluated for the development of new, non toxic and specific anti-herpesvirus drug. Aqueous extracts (AE), ethanolic extracts (EE) and essential oil (EO) of the aerial parts of Thymus capitata were... 16. [The role of the pineal-thymus system in the regulation of autoimmunity, aging and lifespan]. Science.gov (United States) Csaba, György 2016-07-01 Thymus is an immunoendocrine organ, the hormones of which mainly influence its own lymphatic elements. It has a central role in the immune system, the neonatal removal causes the collapse of immune system and the whole organism. The thymic nurse cells select the bone marrow originated lymphocytes and destroy the autoreactive ones, while thymus originated Treg cells suppress the autoreactive cells in the periphery. The involution of the organ starts after birth, however, this truly happens in the end of puberty only, as before this it is overcompensated by developmental processes. From the end of adolescence the involution allows the life, proliferation and enhanced functioning of some autoreactive cells, which gradually wear down the cells and intercellular materials, causing the aging. The enhanced and mass function of autoreactive cells lead to the autoimmune diseases and natural death. This means that the involution of thymus is not a part of the organismic involution, but an originator of it, which is manifested in the lifespan-pacemaker function. In this case aging can be comprehended as a thymus-commanded slow autoimmune process. The neonatal removal of pineal gland leads to the complete destruction of the thymus and the crashing down of the immune system, as well as to wasting disease. The involution of the pineal and thymus runs parallel, because the two organs form a functional unit. It is probable that the pineal gland is responsible for the involution of thymus and also regulates its lifespan determining role. The data reviewed do not prove the exclusive role of pineal-thymus system in the regulation of aging and lifespan, however, calls attention to the suitability of solving this problem alone. PMID:27346473 17. Use of embryonal thymus transplantation in combined treatment of oncologic patients International Nuclear Information System (INIS) Results of combined treatment of 102 patients with mammary gland cancer and of 46 patients with pulmonary cancer are studied. In 75 patients (52 patients with mammary gland cancer and 23 - with pulmonary cancer) embryonal thymus transplantation was carried out; 73 patients entered a test group. It is stated that a single embryonal thymus transplantation is an active immunostimulator and in the process of combined therapy of patients permits to improve 18. Inflammatory pseudotumor of the thymus: A case report and review of the literature OpenAIRE Zhang, Zhefeng; Jin, Feng; Sun, Liguang; Wu, Hao; Chen, Bing; Cui, Youbin 2014-01-01 Inflammatory pseudotumors are rare benign tumors consisting of cellular and stromal elements of a localized reactive process. While inflammatory pseudotumors are commonly detected in the lung and occasionally in other organs, only one case of inflammatory pseudotumor of the thymus has been reported in the literature to date. This report presents a 54-year-old male patient with inflammatory pseudotumor of the thymus accompanied by pulmonary inflammation. The patient presented with chest pain a... 19. What happens to the thymus in children who have undergone a median sternotomy? International Nuclear Information System (INIS) The thymus grows rapidly during fetal life and continues to grow during childhood. When a child undergoes a median sternotomy during cardiac surgery, most of the thymus is removed to gain access to the mediastinum. What happens to the residual thymic tissue in the long term ?To test the hypothesis that residual thymic tissue left after sternotomy regenerates into an identifiable thymus and is visible on MRI. We retrospectively reviewed the cardiac MR images obtained over a 14-month period in all children under the age of 17 years who had undergone a median sternotomy (n=62) to establish the presence/absence of a thymus. We also reviewed the cardiac MR images obtained over the same time period in children who had never undergone open cardiac surgery (n=37). In the sternotomy group, 18 patients (29%) had an identifiable thymus on MR images, compared to 92% (n=34) in the nonsternotomy group. This difference was statistically significant. The majority of children in the study group did not have a visible thymus on MR images, which suggests that in these children any residual thymic tissue left postoperatively does not regenerate. (orig.) 20. Promiscuous Gene Expression in the Thymus: The Root of Central Tolerance Directory of Open Access Journals (Sweden) Danielle A. R. Magalhães 2006-01-01 Full Text Available The thymus is a complex organ with an epithelium formed by two main cell types, the cortical thymic epithelial (cTECs and medullary thymic epithelial cells (mTECs, referred to as stroma. Immature thymocytes arising from the bone marrow, macrophages and dendritic cells also populate the thymus. Thymocytes evolve to mature T cells featuring cell differentiation antigens (CDs, which characterize the phenotypically distinct stages, defined as double-negative (DN, double positive (DP and single positive (SP, based on expression of the coreceptors CD4 and CD8. The thymus is therefore implicated in T cell differentiation and during development into T cells thymocytes are in close association with the stroma. Recent evidence showed that mTECs express a diverse set of genes coding for parenchymal organ specific proteins. This phenomenon has been termed promiscuous gene expression (PGE and has led to the reconsideration of the role of the thymus in central T cell tolerance to self-antigens, which prevents autoimmunity. The evidence of PGE is causing a reanalysis in the scope of central tolerance understanding. We summarize the evidence of PGE in the thymus, focusing particularly the use of cDNA microarray technology for the broad characterization of gene expression and demarcation of PGE emergence during thymus ontogeny. 1. Protection against apoptosis in chicken bursa and thymus cells by phorbol ester in vitro Energy Technology Data Exchange (ETDEWEB) Asakawa, J.; Thorbecke, G.J. (Univ. of New York, New York (United States)) 1991-03-15 Programmed suicide or apoptosis, due to activation of endogenous nucleases, occurs in immature CD4{sup {minus}}85{sup {minus}} mammalian thymus cells. Like the thymus, the bursa of Fabricius is a site of massive lymphopoiesis accompanied by cell death in vivo. In the present study the authors have, therefore, examined whether chicken bursa and thymus cells exhibit apoptosis. Bursa and thymus cells from SC chickens, 4-10 weeks of age, were incubated for 8-24 hrs with various reagents. Genomic DNA was isolated, electrophoresed in 3% Nusieve agarose gels, and examined for patterns of DNA fragmentation. A laddering of DNA in multiples of 200 base pairs, indicative of apoptosis, was observed with both bursa and thymus cells. These patterns of DNA fragmentation from bursa cells could be prevented by adding phorbol myristic acetate during culture and, more effectively, by PMA plus ionomycin, but not by ionomycin alone or by anti-{mu}. PMA did not affect the patterns of DNA fragmentation seen with spleen cells. Addition of the protein kinase C inhibitor staurosporin inhibited the preventive effect of PMA on apoptosis. PMA also greatly promoted the survival of bursa cells in culture, as assayed by percentage cell death and by {sup 3}H-thymidine incorporation. It is concluded that bursa and thymus cells from the chicken exhibit apoptosis. The data further suggest that protein kinase C activation protects apoptosis in cultured bursa cells. 2. Radiographical diagnosis of the thymus in myasthenia gravis. Comparison of pneumomediastinography and computed tomography Energy Technology Data Exchange (ETDEWEB) Tanimura, Shigeo; Banba, Jiro; Masaki, Mikio; Irimoto, Masahiro; Matsushita, Akira 1987-11-01 Comparison of radiographical findings of the thymus between pneumomediastinography and computed tomography were studied in 35 patients with myasthenia gravis. The patients consisted of 10 patients with thymoma and 25 without thymoma confirmed at the operations. Pneumomediastinography was very useful to discern whether the thymoma was invasive or noninvasive, but not contributory to know whether the thymus was composed of folicular lymphoid hyperplasia or normal thyimic tissues. Computed tomography was also useful to dertermine the localization and the invasiveness of the thymoma, but not helpful to know whether the thymus was of follicular lymphoid hyperplasia or normal tissues. However, the finding of ''reticular pattern''-many small nodules scattered resicularly in the thymus-in computed tomography could be regarded as a sign suggesting follicular lymphoid hyperplasia of the thymus. Therfore, both pneumomediastinography and computed tomography were very useful in the diagnosis of the localization and the invasiveness of the thymoma but not for the diagnosis of follicular lymphoid hyperplasia of the thymus. Neverethless the finding of ''reticular pattern'' computred tomography was helpful in the diagnosis of follicular lymphoid hyperplasia. 3. Antioxidative effect of thyme (Thymus vulgaris in sunflower oil Directory of Open Access Journals (Sweden) Zofia Zaborowska 2012-09-01 Full Text Available Background. Lipid oxidation is a main problem during food processing, storage and consumption leading to losses of quality, stability, safety and nutritive value. Antioxidants have been used to prevent oxidation changes and off – flavor development in food products. Aim of the research was to evaluate antioxidative effect of thyme ethanol extract on sunflower oil during its storage in different temperature conditions. Oil samples were stored in darkness at 4°C, 18°C, 38°C. Material and methods. Samples of thyme (thymus vulgaris were purchased at a local pharmacy in Poznań, Poland and sunflower oil was acquired from a local supermarket. Thyme extract was characterized by total polyphenol content. Antioxidant activity was estimated with use of DPPHand ABTSradicals scavenging methods. Ethanol extract of thyme at 1% level was added to sunflower oil. Peroxide value (PV, anisidine value (AV, totox value (TxV and fatty acids (FA content were taken as parameters for evaluation of effectiveness of thyme extract in stabilization of sunflower oil. Results. High polyphenol content, DPPHand ABTSradicals scavenging activity of ethanol thyme extract were evaluated. Results from different parameters were in agreement with other researchers, suggesting the antioxidant effect of thyme on antioxidant stability. Results show that thyme extract prolonged stability of sunflower oil and it may be a potent antioxidant for its stabilization. Conclusions. Ethanol thyme extract may be used as a natural antioxidant to prolong stability of oils. 4. Essential Oils Composition and Antioxidant Properties of Three Thymus Species Directory of Open Access Journals (Sweden) Hamzeh Amiri 2012-01-01 Full Text Available The essential oils of three wild-growing Thymus species, collected from west of Iran during the flowering stage, were obtained by hydrodistillation and analyzed by gas chromatography (GC and gas chromatography/mass spectrometry (GC-MS. Under the optimum extraction and analysis conditions, 44, 38, and 38 constituents (mainly monoterpenes compounds were identified in T. kotschyanus Boiss. and Hohen, T. eriocalyx (Ronniger Jalas, and T. daenensis subsp lancifolius (Celak Jalas which represented 89.9%, 99.7%, and 95.8% of the oils, respectively. The main constituents were thymol (16.4–42.6%, carvacrol (7.6–52.3%, and γ-terpinene (3–11.4%. Antioxidant activity was employed by two complementary test systems, namely, 2,2-diphenyl-1-picrylhydrazyl (DPPH free-radical scavenging and β-carotene/linoleic acid systems. Antioxidant activity of polar subfraction of T. daenensis subsp lancifolius (Celak Jalas was found to be higher than those of the others in DPPH assay, while nonpolar subfraction of T. eriocalyx (Ronniger Jalas has most antioxidant activity in β-carotene/linoleic acid test (19.1±0.1 μg/mL and 96.1±0.8% inhibition rate, resp.. 5. Nicotinamide coenzymes in the rat thymus during the postirradiation period International Nuclear Information System (INIS) Changes in the contents of NADP and NADPN, the activity of glucose-6-phosphate-dehydrogenase and glutathione reductase and the contents of NAD, NADP, SH-groups and ATP were first investigated in the thymus of γ-irradiated (900 R) rats. A decrease in the contents of all the nicotinamide coenzymes and SH-groups was detected during the first minutes after irradiation. In an hour, the NADPN content exceeded normal by 43.2 per cent while the other parameters under study normalized. In 4 to 24 hours a repeated reduction in the content of all the nicotinamide coenzymes was accompanied by the ATP decrease. After 72 hours the level of the nicotinamide coenzymes normalized and the ATP content remained below normal. The activity of glucose-6-phosphate-dehydrogenase was 25-30-per cent higher during the first 60 minutes after irradiation; the activity of glutathione reductase was invariable. Mechanisms of the postirradiation changes in the nicotinamide coenzymes and their association with the state of the thiolo-disulphide system, bioenergetics and carbohydrate metabolism were discussed 6. Chemotaxonomic study on Thymus xtoletanus Ladero and its parental species Directory of Open Access Journals (Sweden) José B. Salas 2011-04-01 Full Text Available We analysed the essential oils of cultivated material of Thymus xtoletanus Ladero and its parents, Th. mastichina (L. L. and Th. villosus subsp. lusitanicus (Boiss. Coutinho, with seeds from the same locality in the centre of the Iberian Peninsula. The essential oil of Th. xtoletanus, which had not been analyzed previously, presented 1,8-cineole as the major component (25.5%, as was also the case for Th. mastichina (76.1%. Other components with a major presence in Th. xtoletanus and Th. villosus subsp. lusitanicus were [(Z-β-ocimene (8.1%; camphor (4.5%; sabinene (3.2%; α-pinene (2.8%], and [(Z-β-ocimene (4.1%, camphor (9.8%, sabinene (2.8%, α-pinene (7.1%], respectively. However, in the hybrid the components β-phelandrene (14.5%, limonene (6.9%, (E-γ-bisabolene (3.5%, and viridiflorol (3.3% stood out, inter alia, whereas their presence in the parents was limited. The study confirms the hybrid origin of Th. xtoletanus as intermediate between Th. mastichina and Th. villosus subsp. lusitanicus. 7. Histomorphological changes in thymus and spleen after cyclooxygenase inhibitors treatment Directory of Open Access Journals (Sweden) Poeta O.N. 2009-01-01 Full Text Available The influence of cyclooxygenase inhibitors on the lymphoid organs histomorphology has been examined in the matured outbread white mice. Diclofenac, meloxicam, celecoxib, but not rofecoxib has shown depressive action on the im-munocompetetive organs histomorphologic structure. Macroscopic study has revealed a decrease in the weight of the spleen and thymus. Light microscopy has shown a decrease in the number of thymocytes, due to degradation of cortex area. In the lobular medulla it has been observed microcirculation changes in the view of venules and capillaries distention, arteriolar wall thickening. In the spleen it has been shown a decrease in the white pulp volume, disappearing of the reactive centers in follicles. Also subcapsular edema and relative stroma volume increase has been seen frequently. The use of highly selective COG-2 inhibitor rofecoxib has not revealed statistically truthful changes in microscopic examination in comparison to the control group. That could vote for the absence of depressive action on the immune organ histomorphologic structure. 8. Glandular Trichomes and Essential Oil of Thymus quinquecostatus Directory of Open Access Journals (Sweden) Ping Jia 2013-01-01 Full Text Available The distribution and types of glandular trichomes and essential oil chemistry of Thymus quinquecostatus were studied. The glandular trichomes are distributed on the surface of stem, leaf, rachis, calyx and corolla, except petiole, pistil and stamen. Three morphologically distinct types of glandular trichomes are described. Peltate trichomes, consisting of a basal cell, a stalk cell and a 12-celled head, are distributed on the stem, leaf, corolla and outer side of calyx. Capitate trichomes, consisting of a unicellular base, a 1–2-celled stalk and a unicellular head, are distributed more diffusely than peltate ones, existing on stem, leaf, rachis and calyx. Digitiform trichomes are just distributed on the outer side of corolla, consisting of 1 basal cell, 3 stalk cells and 1 head cell. All three types of glandular trichomes can secrete essential oil, and in small capitate trichomes of rachis, all peltate trichomes and digitiform trichomes, essential oil is stored in a large subcuticular space, released by cuticle rupture, whereas, in other capitate trichomes, essential oil crosses the thin cuticle. The essential oil of T. quinquecostatus is yellow, and its content is highest in the growth period. 68 constituents were identified in the essential oils. The main constituent is linalool. 9. Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms International Nuclear Information System (INIS) Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999-2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals' size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms-modeled entirely in mesh surfaces-of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte Carlo 10. Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms Science.gov (United States) Hum Na, Yong; Zhang, Binquan; Zhang, Juying; Caracappa, Peter F.; Xu, X. George 2010-07-01 Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999-2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals' size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms—modeled entirely in mesh surfaces—of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte 11. Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms Energy Technology Data Exchange (ETDEWEB) Na, Yong Hum; Xu, X George [Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Zhang Binquan; Zhang Juying; Caracappa, Peter F, E-mail: [email protected] [Nuclear Engineering and Engineering Physics, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States) 2010-07-07 Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999-2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals' size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms-modeled entirely in mesh surfaces-of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte 12. Immunomodulatory properties of human adult and fetal multipotent mesenchymal stem cells Directory of Open Access Journals (Sweden) Sytwu Huey-Kang 2011-07-01 Full Text Available Abstract In recent years, a large number of studies have contributed to our understanding of the immunomodulatory mechanisms used by multipotent mesenchymal stem cells (MSCs. Initially isolated from the bone marrow (BM, MSCs have been found in many tissues but the strong immunomodulatory properties are best studied in BM MSCs. The immunomodulatory effects of BM MSCs are wide, extending to T lymphocytes and dendritic cells, and are therapeutically useful for treatment of immune-related diseases including graft-versus-host disease as well as possibly autoimmune diseases. However, BM MSCs are very rare cells and require an invasive procedure for procurement. Recently, MSCs have also been found in fetal-stage embryo-proper and extra-embryonic tissues, and these human fetal MSCs (F-MSCs have a higher proliferative profile, and are capable of multilineage differentiation as well as exert strong immunomodulatory effects. As such, these F-MSCs can be viewed as alternative sources of MSCs. We review here the current understanding of the mechanisms behind the immunomodulatory properties of BM MSCs and F-MSCs. An increase in our understanding of MSC suppressor mechanisms will offer insights for prevalent clinical use of these versatile adult stem cells in the near future. 13. Morphometry Of Jugular Foramen Of Dry Adult Human Skulls Of South India. Directory of Open Access Journals (Sweden) Ashwin Krishnamurthy 2011-09-01 Full Text Available Jugular foramen (JF lies between the occipital and the petrosal part of the temporal bone, and allows the passage of important nerves and vascular elements i.e. the glossopharyngeal, vagus, and accessory nerves and the internal jugular vein. It is a potential site for development of schwannomas, metastatic lesions, and infiltrative inflammatory processes from the surrounding structures such as middle ear. JF is difficult to approach surgically, but recent advanced techniques especially image intensifier to guide the suboccipital lateral approach have made the treatment possible despite the difficulties. Hence a detailed morphological and anatomical knowledge of this region is required. The morphologic dimensions, presence or absence of septation etc varies in various races and ethnic groups as reported in previous literature. But such detailed study has been lacking in south Indian population .Thus the present descriptive study was conducted in department of Anatomy, Kasturba Medical College, Mangalore on 50 dried adult human skulls i.e. 100 JF of Dravidian (south Indian origin. The maximum antero-posterior and transverse diameter and depth of the jugular fossa of both sides were measured and septation was 6% on the right side and 8% on the left side using vernier calipers. The presence of spicules / septation of the jugular foramen were also observed on both sides. The obtained results presented variations regarding some parameters when compared to previous studies, thus making it evident the significance of race in the morphometric measurements and characteristics of the JF. 14. Growth of the human lens in the Indian adult population: Preliminary observations Directory of Open Access Journals (Sweden) Ashik Mohamed 2012-01-01 Full Text Available Context: The eye lens grows throughout life by the addition of new cells inside the surrounding capsule. How this growth affects the properties of the lens is essential for understanding disorders such as cataract and presbyopia. Aims: To examine growth of the human lens in the Indian population and compare this with the growth in Western populations by measuring in vitro dimensions together with wet and dry weights. Settings and Design: The study was conducted at the research wing of a tertiary eye care center in South India and the study design was prospective. Materials and Methods: Lenses were removed from eye bank eyes and their dimensions measured with a digital caliper. They were then carefully blotted dry and weighed before being placed in 5% buffered formalin. After 1 week fixation, the lenses were dried at 80 °C until constant weight was achieved. The constant weight was noted as the dry weight of the lens. Statistical Analysis Used: Lens parameters were analyzed as a function of age using linear and logarithmic regression methods. Results: Data were obtained for 251 lenses, aged 16-93 years, within a median postmortem time of 22 h. Both wet and dry weights increased linearly at 1.24 and 0.44 mg/year, respectively, throughout adult life. The dimensions also increased continuously throughout this time. Conclusions: Over the age range examined, lens growth in the Indian population is very similar to that in Western populations. 15. Open-Porous Hydroxyapatite Scaffolds for Three-Dimensional Culture of Human Adult Liver Cells Directory of Open Access Journals (Sweden) Anthony Finoli 2016-01-01 Full Text Available Liver cell culture within three-dimensional structures provides an improved culture system for various applications in basic research, pharmacological screening, and implantable or extracorporeal liver support. Biodegradable calcium-based scaffolds in such systems could enhance liver cell functionality by providing endothelial and hepatic cell support through locally elevated calcium levels, increased surface area for cell attachment, and allowing three-dimensional tissue restructuring. Open-porous hydroxyapatite scaffolds were fabricated and seeded with primary adult human liver cells, which were embedded within or without gels of extracellular matrix protein collagen-1 or hyaluronan. Metabolic functions were assessed after 5, 15, and 28 days. Longer-term cultures exhibited highest cell numbers and liver specific gene expression when cultured on hydroxyapatite scaffolds in collagen-1. Endothelial gene expression was induced in cells cultured on scaffolds without extracellular matrix proteins. Hydroxyapatite induced gene expression for cytokeratin-19 when cells were cultured in collagen-1 gel while culture in hyaluronan increased cytokeratin-19 gene expression independent of the use of scaffold in long-term culture. The implementation of hydroxyapatite composites with extracellular matrices affected liver cell cultures and cell differentiation depending on the type of matrix protein and the presence of a scaffold. The hydroxyapatite scaffolds enable scale-up of hepatic three-dimensional culture models for regenerative medicine applications. 16. Low Power Laser Irradiation Stimulates the Proliferation of Adult Human Retinal Pigment Epithelial Cells in Culture Science.gov (United States) Song, Qing; Uygun, Basak; Banerjee, Ipsita; Nahmias, Yaakov; Zhang, Quan; Berthiaume, François; Latina, Mark; Yarmush, Martin L. 2015-01-01 We investigated the effects of low power laser irradiation on the proliferation of retinal pigment epithelial (RPE) cells. Adult human RPE cells were artificially pigmented by preincubation with sepia melanin, and exposed to a single sublethal laser pulse (590 nm, 1 µs, <200 mJ/cm2). DNA synthesis, cell number, and growth factor activity in irradiated RPE cells were subsequently monitored. The effect of sublethal laser irradiation on the “wound” healing response of an RPE monolayer in an in vitro scratch assay was also investigated. Single pulsed laser irradiation increased DNA synthesis in pigmented RPE cells measured 6 h post-treatment. In the scratch assay, laser irradiation increased the rates of cell proliferation and wound closure. Conditioned medium, collected 48 h following laser treatment, increased cell proliferation of unirradiated cells. Irradiation increased RPE cell secretion of platelet-derived growth factor (PDGF)-B chain, and increased mRNA levels of several growth factors and their receptors, including PDGF, transforming growth factor-β1, basic fibroblast growth factor, epidermal growth factor, insulin-like growth factor, as well as heat shock proteins. This demonstrates, for the first time, that low power single pulsed laser irradiation stimulates the proliferation of RPE cells, and upregulates growth factors that are mitogenic for RPE cells. PMID:26740823 17. Open-Porous Hydroxyapatite Scaffolds for Three-Dimensional Culture of Human Adult Liver Cells Science.gov (United States) Schmelzer, Eva; Over, Patrick; Nettleship, Ian; Gerlach, Joerg C. 2016-01-01 Liver cell culture within three-dimensional structures provides an improved culture system for various applications in basic research, pharmacological screening, and implantable or extracorporeal liver support. Biodegradable calcium-based scaffolds in such systems could enhance liver cell functionality by providing endothelial and hepatic cell support through locally elevated calcium levels, increased surface area for cell attachment, and allowing three-dimensional tissue restructuring. Open-porous hydroxyapatite scaffolds were fabricated and seeded with primary adult human liver cells, which were embedded within or without gels of extracellular matrix protein collagen-1 or hyaluronan. Metabolic functions were assessed after 5, 15, and 28 days. Longer-term cultures exhibited highest cell numbers and liver specific gene expression when cultured on hydroxyapatite scaffolds in collagen-1. Endothelial gene expression was induced in cells cultured on scaffolds without extracellular matrix proteins. Hydroxyapatite induced gene expression for cytokeratin-19 when cells were cultured in collagen-1 gel while culture in hyaluronan increased cytokeratin-19 gene expression independent of the use of scaffold in long-term culture. The implementation of hydroxyapatite composites with extracellular matrices affected liver cell cultures and cell differentiation depending on the type of matrix protein and the presence of a scaffold. The hydroxyapatite scaffolds enable scale-up of hepatic three-dimensional culture models for regenerative medicine applications. 18. Dynamic gene expression in the human cerebral cortex distinguishes children from adults. Science.gov (United States) Sterner, Kirstin N; Weckle, Amy; Chugani, Harry T; Tarca, Adi L; Sherwood, Chet C; Hof, Patrick R; Kuzawa, Christopher W; Boddy, Amy M; Abbas, Asad; Raaum, Ryan L; Grégoire, Lucie; Lipovich, Leonard; Grossman, Lawrence I; Uddin, Monica; Goodman, Morris; Wildman, Derek E 2012-01-01 In comparison with other primate species, humans have an extended juvenile period during which the brain is more plastic. In the current study we sought to examine gene expression in the cerebral cortex during development in the context of this adaptive plasticity. We introduce an approach designed to discriminate genes with variable as opposed to uniform patterns of gene expression and found that greater inter-individual variance is observed among children than among adults. For the 337 transcripts that show this pattern, we found a significant overrepresentation of genes annotated to the immune system process (pFDR ~/= 0). Moreover, genes known to be important in neuronal function, such as brain-derived neurotrophic factor (BDNF), are included among the genes more variably expressed in childhood. We propose that the developmental period of heightened childhood neuronal plasticity is characterized by more dynamic patterns of gene expression in the cerebral cortex compared to adulthood when the brain is less plastic. That an overabundance of these genes are annotated to the immune system suggests that the functions of these genes can be thought of not only in the context of antigen processing and presentation, but also in the context of nervous system development. PMID:22666384 19. An association between human hippocampal volume and topographical memory in healthy young adults. Directory of Open Access Journals (Sweden) Tom eHartley 2012-12-01 Full Text Available The association between human hippocampal structure and topographical memory was investigated in healthy adults (N=30. Structural MR images were acquired, and voxel-based morphometry (VBM was used to estimate local gray matter volume throughout the brain. A complementary automated mesh-based segmentation approach was used to independently isolate and measure specified structures including the hippocampus. Topographical memory was assessed using a version of the Four Mountains Task, a short test designed to target hippocampal spatial function. Each item requires subjects to briefly study a landscape scene before recognizing the depicted place from a novel viewpoint and under altered non-spatial conditions when presented amongst similar alternative scenes. Positive correlations between topographical memory performance and hippocampal volume were observed in both VBM and segmentation-based analyses. Score on the topographical memory task was also correlated with the volume of some subcortical structures, extra-hippocampal gray matter and total brain volume, with the most robust and extensive covariation seen in circumscribed neocortical regions in the insula and anterior temporal lobes. Taken together with earlier findings, the results suggest that global variations in brain morphology affect the volume of the hippocampus and its specific contribution to topographical memory. We speculate that behavioral variation might arise directly through the impact of resource constraints on spatial representations in the hippocampal formation and its inputs, and perhaps indirectly through an increased reliance on non-allocentric strategies. 20. Application of PLE for the determination of essential oil components from Thymus vulgaris L. Science.gov (United States) Dawidowicz, Andrzej L; Rado, Ewelina; Wianowska, Dorota; Mardarowicz, Marek; Gawdzik, Jan 2008-08-15 Essential plants, due to their long presence in human history, their status in culinary arts, their use in medicine and perfume manufacture, belong to frequently examined stock materials in scientific and industrial laboratories. Because of a large number of freshly cut, dried or frozen plant samples requiring the determination of essential oil amount and composition, a fast, safe, simple, efficient and highly automatic sample preparation method is needed. Five sample preparation methods (steam distillation, extraction in the Soxhlet apparatus, supercritical fluid extraction, solid phase microextraction and pressurized liquid extraction) used for the isolation of aroma-active components from Thymus vulgaris L. are compared in the paper. The methods are mainly discussed with regard to the recovery of components which typically exist in essential oil isolated by steam distillation. According to the obtained data, PLE is the most efficient sample preparation method in determining the essential oil from the thyme herb. Although co-extraction of non-volatile ingredients is the main drawback of this method, it is characterized by the highest yield of essential oil components and the shortest extraction time required. Moreover, the relative peak amounts of essential components revealed by PLE are comparable with those obtained by steam distillation, which is recognized as standard sample preparation method for the analysis of essential oils in aromatic plants. PMID:18656673 1. XML Investigating the Phytochemical, Antibacterial and Antifungal Effects of Thymus Vulgaris and Cuminum Cyminum Essential Oils Directory of Open Access Journals (Sweden) Soghra Valizadeh (MSc 2016-02-01 Full Text Available Background and Objective: The aim of this study was to determine the chemical composition, antibacterial and antifungal effects of Thymus vulgaris and Cuminum Cyminum essential oils against foodborne pathogens and Candida species in vitro. Methods: The essential oils were extracted from the aerial parts of Thymus vulgaris and dried Cuminum Cyminum seeds using a Clevenger apparatus for 3 hours. Analysis of the essential oils’ constituents was performed using gas chromatography-mass spectrophotometry. The antibacterial activity of Cuminum Cyminum essential oil and essential oil of Thymus vulgaris against Bacillus cereus, Listeria monocytogenes, Escherichia coli and Salmonella typhimurium were evaluated in agar culture medium. The minimum inhibitory concentration (MIC of these essential oils against fungal strains of Candida albicans, C. tropicalis, C. parapsilosis and C. dubliniensis was measured. Results: Thymol (64.45% and cuminaldehyde (29.02% were the main components of the essential oil of Thymus vulgaris and Cuminum Cyminum, respectively. The largest inhibition zone diameter in the essential oils of Thymus vulgaris and Cuminum Cyminum in the agar disk diffusion method was related to B. cereus with 30 and 21 mm diameter, respectively. The largest growth inhibition zone diameter by the essential oil of Thymus vulgaris in the well diffusion method was 21 mm and against B. cereus. The MIC of essential oil of Thymus vulgaris in the microdilution method was 0.09% against all the four Candida strains. The MIC of Cuminum Cyminum essential oil against strains of C. albicans and C. tropicalis was 0.39%, while it was found as 0.19% against C. parapsilosis and C. dubliniensis. Conclusion: In this study, Cuminum Cyminum essential oil and essential oil of Thymus vulgaris show suitable inhibitory effects against the growth of bacteria using well and disk diffusion methods. Regarding the antifungal effects, the MIC of essential oil of Thymus vulgaris is 2. Inhibition of glycogen synthase kinase-3 enhances the differentiation and reduces the proliferation of adult human olfactory epithelium neural precursors Energy Technology Data Exchange (ETDEWEB) Manceur, Aziza P. [Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto, Toronto, Ontario (Canada); Donnelly Centre, University of Toronto, Toronto, Ontario (Canada); Tseng, Michael [Laboratory of Cellular and Molecular Pathophysiology, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Ontario (Canada); Department of Psychiatry, University of Toronto, Toronto, ON (Canada); Institute of Medical Science, University of Toronto, Toronto, ON (Canada); Holowacz, Tamara [Donnelly Centre, University of Toronto, Toronto, Ontario (Canada); Witterick, Ian [Institute of Medical Science, University of Toronto, Toronto, ON (Canada); Department of Otolaryngology, Head and Neck Surgery, University of Toronto, ON (Canada); Weksberg, Rosanna [Institute of Medical Science, University of Toronto, Toronto, ON (Canada); The Hospital for Sick Children, Research Institute, Program in Genetics and Genomic Biology, Toronto, Ontario Canada (Canada); McCurdy, Richard D. [The Hospital for Sick Children, Research Institute, Program in Genetics and Genomic Biology, Toronto, Ontario Canada (Canada); Warsh, Jerry J. [Laboratory of Cellular and Molecular Pathophysiology, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Ontario (Canada); Department of Psychiatry, University of Toronto, Toronto, ON (Canada); Institute of Medical Science, University of Toronto, Toronto, ON (Canada); Audet, Julie, E-mail: [email protected] [Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto, Toronto, Ontario (Canada); Donnelly Centre, University of Toronto, Toronto, Ontario (Canada) 2011-09-10 The olfactory epithelium (OE) contains neural precursor cells which can be easily harvested from a minimally invasive nasal biopsy, making them a valuable cell source to study human neural cell lineages in health and disease. Glycogen synthase kinase-3 (GSK-3) has been implicated in the etiology and treatment of neuropsychiatric disorders and also in the regulation of murine neural precursor cell fate in vitro and in vivo. In this study, we examined the impact of decreased GSK-3 activity on the fate of adult human OE neural precursors in vitro. GSK-3 inhibition was achieved using ATP-competitive (6-bromoindirubin-3'-oxime and CHIR99021) or substrate-competitive (TAT-eIF2B) inhibitors to eliminate potential confounding effects on cell fate due to off-target kinase inhibition. GSK-3 inhibitors decreased the number of neural precursor cells in OE cell cultures through a reduction in proliferation. Decreased proliferation was not associated with a reduction in cell survival but was accompanied by a reduction in nestin expression and a substantial increase in the expression of the neuronal differentiation markers MAP1B and neurofilament (NF-M) after 10 days in culture. Taken together, these results suggest that GSK-3 inhibition promotes the early stages of neuronal differentiation in cultures of adult human neural precursors and provide insights into the mechanisms by which alterations in GSK-3 signaling affect adult human neurogenesis, a cellular process strongly suspected to play a role in the etiology of neuropsychiatric disorders. 3. Inhibition of glycogen synthase kinase-3 enhances the differentiation and reduces the proliferation of adult human olfactory epithelium neural precursors International Nuclear Information System (INIS) The olfactory epithelium (OE) contains neural precursor cells which can be easily harvested from a minimally invasive nasal biopsy, making them a valuable cell source to study human neural cell lineages in health and disease. Glycogen synthase kinase-3 (GSK-3) has been implicated in the etiology and treatment of neuropsychiatric disorders and also in the regulation of murine neural precursor cell fate in vitro and in vivo. In this study, we examined the impact of decreased GSK-3 activity on the fate of adult human OE neural precursors in vitro. GSK-3 inhibition was achieved using ATP-competitive (6-bromoindirubin-3'-oxime and CHIR99021) or substrate-competitive (TAT-eIF2B) inhibitors to eliminate potential confounding effects on cell fate due to off-target kinase inhibition. GSK-3 inhibitors decreased the number of neural precursor cells in OE cell cultures through a reduction in proliferation. Decreased proliferation was not associated with a reduction in cell survival but was accompanied by a reduction in nestin expression and a substantial increase in the expression of the neuronal differentiation markers MAP1B and neurofilament (NF-M) after 10 days in culture. Taken together, these results suggest that GSK-3 inhibition promotes the early stages of neuronal differentiation in cultures of adult human neural precursors and provide insights into the mechanisms by which alterations in GSK-3 signaling affect adult human neurogenesis, a cellular process strongly suspected to play a role in the etiology of neuropsychiatric disorders. 4. Chemical Composition and Antimicrobial Activity of the Essential Oils from Two Species of Thymus Growing Wild in Southern Italy Directory of Open Access Journals (Sweden) Felice Senatore 2009-11-01 Full Text Available The volatile constituents of the aerial parts of two samples of Thymus longicaulis C. Presl, collected in Campania and in Sicily, and two samples of Thymus pulegioides L. from the same regions, were extracted by hydrodistillation and analyzed. Considering the four oils together, seventy-eight different compounds were identified: 57 for Thymus longicaulis from Sicily (91.1% of the total oil, 40 for Thymus longicaulis from Campania (91.5% of the oil, 39 for Thymus pulegioides from Sicily (92.5% of the oil and 29 for Thymus pulegioides from Campania (90.1% of the oil. The composition of the oils is different, although the most abundant components are identical in T. pulegioides. The essential oils showed antibacterial activity against eight selected microorganisms. 5. Human parvovirus B19-induced aplastic crisis in an adult patient with hereditary spherocytosis: a case report and review of the literature OpenAIRE Kobayashi, Yujin; Hatta, Yoshihiro; Ishiwatari, Yusaku; Kanno, Hitoshi; Takei, Masami 2014-01-01 Background Although there are several case reports of human parvovirus B19 infection in patients with hereditary spherocytosis, no systematic reviews of adult patients with hereditary spherocytosis with human parvovirus B19 infection have been published as clinical case reports. In this study, we report a case of aplastic crisis due to human parvovirus B19 infection in an adult patient with hereditary spherocytosis. Case presentation A 33-year-old woman with hereditary spherocytosis and galls... 6. Ionizing radiation and the thymus : effects of whole-body irradiation with fast fission neutrons and X-rays on the murine thymus NARCIS (Netherlands) R. Huiskamp (René) 1986-01-01 textabstractAs described in Chapter I of this thesis, the thymus is an extremely complex lympho-epithelial organ in which bone marrow-derived lymphoid precursor cells, i.e. prothymocytes, differentiate and mature in a stromal matrix. During their differentiation in this specialized microenvironment, 7. In vitro Antimicrobial, Cytotoxic and Radical Scavenging Activities and Chemical Constituents of the Endemic Thymus laevigatus (Vahl Directory of Open Access Journals (Sweden) Mohamed Al-Fatimi 2010-01-01 Full Text Available The leaves of Thymus laevigatus (Vahl, Lamiaceae (Labiatae, an endemic species of Yemen, are traditionally used in the treatment of various disorders including stomach and respiratory system. In a first biological and chemical study of this endemic species we investigated antimicrobial, cytotoxic and antioxidant activities of different extracts of the leaves of this plant. The preliminary phytochemical screening of extracts composition was performed by TLC while the composition of the essential oil was determined by GC-MS. Twelve constituents were detected from the essential oil, which constituted 99.6 % of the total amount. The major constituents of the oil were: carvacrol (84.3 %, p-cymene (4.1 % p-mentha-1, 4-diene (4.0 % and trans-anethole (3.6%. The main active components were identified by TLC as carvacrol and anethole for dichloromethane extract and as non-volatile phenols and flavonoids for the methanol extract. The methanol, dichloromethane and aqueous extracts were tested for their antimicrobial activities against five bacteria strains and six human pathogenic fungi. Both methanol and dichloromethane showed strong activities against most human pathogenic strains. In the contrast, methanol extract showed broader and stronger antibacterial activities than the dichloromethane extract, especially against the Gram-negative bacterium Pseudomonas aeruginosa. The methanol extract showed the same strong radical scavenging activity in the DPPH assay (14.9mg/ml, when compared to the standard antioxidant, ascorbic acid. In contrast, the cytotoxic activity of the methanol against FL cells, a human amniotic epithelial cell line, was only moderate (IC50 298, 8 mg/ml. On the contrary, the water extract did not show any biological activity. Results presented here suggest that the essential oil and extracts of Thymus laevigatus possess strong antimicrobial and antioxidant properties, and therefore, they can be used as a natural preservative ingredient 8. FASH and MASH: female and male adult human phantoms based on polygon mesh surfaces: I. Development of the anatomy International Nuclear Information System (INIS) Among computational models, voxel phantoms based on computer tomographic (CT), nuclear magnetic resonance (NMR) or colour photographic images of patients, volunteers or cadavers have become popular in recent years. Although being true to nature representations of scanned individuals, voxel phantoms have limitations, especially when walled organs have to be segmented or when volumes of organs or body tissues, like adipose, have to be changed. Additionally, the scanning of patients or volunteers is usually made in supine position, which causes a shift of internal organs towards the ribcage, a compression of the lungs and a reduction of the sagittal diameter especially in the abdominal region compared to the regular anatomy of a person in the upright position, which in turn can influence organ and tissue absorbed or equivalent dose estimates. This study applies tools developed recently in the areas of computer graphics and animated films to the creation and modelling of 3D human organs, tissues, skeletons and bodies based on polygon mesh surfaces. Female and male adult human phantoms, called FASH (Female Adult meSH) and MASH (Male Adult meSH), have been designed using software, such as MakeHuman, Blender, Binvox and ImageJ, based on anatomical atlases, observing at the same time organ masses recommended by the International Commission on Radiological Protection for the male and female reference adult in report no 89. 113 organs, bones and tissues have been modelled in the FASH and the MASH phantoms representing locations for adults in standing posture. Most organ and tissue masses of the voxelized versions agree with corresponding data from ICRP89 within a margin of 2.6%. Comparison with the mesh-based male RPIAM and female RPIAF phantoms shows differences with respect to the material used, to the software and concepts applied, and to the anatomies created. 9. Thoracic computer tomography for the evaluation of the thymus gland in cases of myasthenia gravis Energy Technology Data Exchange (ETDEWEB) Druschky, K.F.; Stadler, H.W.; Daun, H. 1981-01-01 Hyperplasia of the thymus gland is observed in 65% of all patients with myasthenia gravis, while the incidence of thymus tumor is reported to be 8.5-28%. Conventional radiological techniques provide little information in the diagnosis of mediastinal lesions. Even a clearly developed thymus tumor can escape clinical detection. Since March 1978 thoracic computer tomography has been performed in addition to X-rays of the chest in a series of 19 patients with myasthenia ravis, 10 women and 9 men ranging in age from 15-71 years and in 3 patients with suspected thymomas but without myasthenia gravis. These examinations were carried out with a Somatom II (Siemens) since September 1979. On the average 15-20 scans were made at the level of the upper two-third of the sternum. The chest X-rays in 2 planes revealed signs of a thymus tumor in 3 female patients. Thoracic computer tomography showed definite signs of a space-occupying lesion in the anterior mediastinum in 11 cases. At thymectomy 6 patients were found to have hyperplasia of the thymus, 2 patients had a benign thymoma and 3 patients a malignant thymoma. In 6 cases computer tomography showed only slight changes and in 5 patients no pathological findings could be demonstrated in the thymus gland. Thoracic computer tomography is a relatively harmless diagnostic measure without any risk for the patient. It has a high resolution and great accuracy in the evaluation of the thymus gland and is therefore the method of choice for the diagnosis of patients with myasthenia gravis. 10. Thoracic computer tomography for the evaluation of the thymus gland in cases of myasthenia gravis International Nuclear Information System (INIS) Hyperplasia of the thymus gland is observed in 65% of all patients with myasthenia gravis, while the incidence of thymus tumor is reported to be 8.5-28%. Conventional radiological techniques provide little information in the diagnosis of mediastinal lesions. Even a clearly developed thymus tumor can escape clinical detection. Since March 1978 thoracic computer tomography has been performed in addition to X-rays of the chest in a series of 19 patients with myasthenia ravis, 10 women and 9 men ranging in age from 15-71 years and in 3 patients with suspected thymomas but without myasthenia gravis. These examinations were carried out with a Somatom II (Siemens) since September 1979. On the average 15-20 scans were made at the level of the upper two-third of the sternum. The chest X-rays in 2 planes revealed signs of a thymus tumor in 3 female patients. Thoracic computer tomography showed definite signs of a space-occupying lesion in the anterior mediastinum in 11 cases. At thymectomy 6 patients were found to have hyperplasia of the thymus, 2 patients had a benign thymoma and 3 patients a malignant thymoma. In 6 cases computer tomography showed only slight changes and in 5 patients no pathological findings could be demonstrated in the thymus gland. Thoracic computer tomography is a relatively harmless diagnostic measure without any risk for the patient. It has a high resolution and great accuracy in the evaluation of the thymus gland and is therefore the method of choice for the diagnosis of patients with myasthenia gravis. (orig.) 11. cap alpha. -skeletal and. cap alpha. -cardiac actin genes are coexpressed in adult human skeletal muscle and heart Energy Technology Data Exchange (ETDEWEB) Gunning, P.; Ponte, P.; Blau, H.; Kedes, L. 1983-11-01 The authors determined the actin isotypes encoded by 30 actin cDNA clones previously isolated from an adult human muscle cDNA library. Using 3' untranslated region probes, derived from ..cap alpha.. skeletal, ..beta..- and ..gamma..-actin cDNAs and from an ..cap alpha..-cardiac actin genomic clone, they showed that 28 of the cDNAs correspond to ..cap alpha..-skeletal actin transcripts. Unexpectedly, however, the remaining two cDNA clones proved to derive from ..cap alpha..-cardiac actin mRNA. Sequence analysis confirmed that the two skeletal muscle ..cap alpha..-cardiac actin cDNAs are derived from transcripts of the cloned ..cap alpha..-cardiac actin gene. Comparison of total actin mRNA levels in adult skeletal muscle and adult heart revealed that the steady-state levels in skeletal muscle are about twofold greater, per microgram of total cellular RNA, than those in heart. Thus, in skeletal muscle and in heart, both of the sarcomeric actin mRNA isotypes are quite abundant transcripts. They conclude that ..cap alpha..-skeletal and ..cap alpha..-cardiac actin genes are coexpressed as an actin pair in human adult striated muscles. Since the smooth-muscle actins (aortic and stomach) and the cytoplasmic actins (..beta.. and ..gamma..) are known to be coexpressed in smooth muscle and nonmuscle cells, respectively, they postulate that coexpression of actin pairs may be a common feature of mammalian actin gene expression in all tissues. 12. Protocol to isolate a large amount of functional oligodendrocyte precursor cells from the cerebral cortex of adult mice and humans. Directory of Open Access Journals (Sweden) Eva María Medina-Rodríguez Full Text Available During development, oligodendrocytes are generated from oligodendrocyte precursor cells (OPCs, a cell type that is a significant proportion of the total cells (3-8% in the adult central nervous system (CNS of both rodents and humans. Adult OPCs are responsible for the spontaneous remyelination that occurs in demyelinating diseases like Multiple Sclerosis (MS and they constitute an interesting source of cells for regenerative therapy in such conditions. However, there is little data regarding the neurobiology of adult OPCs isolated from mice since an efficient method to isolate them has yet to be established. We have designed a protocol to obtain viable adult OPCs from the cerebral cortex of different mouse strains and we have compared its efficiency with other well-known methods. In addition, we show that this protocol is also useful to isolate functional OPCs from human brain biopsies. Using this method we can isolate primary cortical OPCs in sufficient quantities so as to be able to study their survival, maturation and function, and to facilitate an evaluation of their utility in myelin repair. 13. Estimated Human and Economic Burden of Four Major Adult Vaccine-Preventable Diseases in the United States, 2013. Science.gov (United States) McLaughlin, John M; McGinnis, Justin J; Tan, Litjen; Mercatante, Annette; Fortuna, Joseph 2015-08-01 Low uptake of routinely recommended adult immunizations is a public health concern. Using data from the peer-reviewed literature, government disease-surveillance programs, and the US Census, we developed a customizable model to estimate human and economic burden caused by four major adult vaccine-preventable diseases (VPD) in 2013 in the United States, and for each US state individually. To estimate the number of cases for each adult VPD for a given population, we multiplied age-specific incidence rates obtained from the literature by age-specific 2013 Census population data. We then multiplied the estimated number of cases for a given population by age-specific, estimated medical and indirect (non-medical) costs per case. Adult VPDs examined were: (1) influenza, (2) pneumococcal disease (both invasive disease and pneumonia), (3) herpes zoster (shingles), and (4) pertussis (whooping cough). Sensitivity analyses simulated the impact of various epidemiological scenarios on the total estimated economic burden. Estimated US annual cost for the four adult VPDs was26.5 billion (B) among adults aged 50 years and older, $15.3B (58 %) of which was attributable to those 65 and older. Among adults 50 and older, influenza, pneumococcal disease, herpes zoster, and pertussis made up$16.0B (60 %), $5.1B (19 %),$5.0B (19 %), and $0.4B (2 %) of the cost, respectively. Among those 65 and older, they made up$8.3B (54 %), $3.8B (25 %),$3.0B (20 %), and 0.2B (1 %) of the cost, respectively. Most (80-85 %) pneumococcal costs stemmed from nonbacteremic pneumococcal pneumonia (NPP). Cost attributable to adult VPD in the United States is substantial. Broadening adult immunization efforts beyond influenza only may help reduce the economic burden of adult VPD, and a pneumococcal vaccination effort, primarily focused on reducing NPP, may constitute a logical starting place. Sensitivity analyses revealed that a pandemic influenza season or change in size of the US elderly population
14. Expression of FGFR3 during human testis development and in germ cell-derived tumours of young adults
DEFF Research Database (Denmark)
Ewen, Katherine A; Olesen, Inge A; Winge, Sofia B;
2013-01-01
development and to ascertain whether FGFR3 signalling is linked to germ cell proliferation and the pathogenesis of testicular germ cell tumours (TGCTs) of young adult men. Using RT-PCR, immunohistochemistry and Western blotting, we examined 58 specimens of human testes throughout development for FGFR3...... expression, and then compared expression of FGFR3 with proliferation markers (PCNA or Ki67). We also analysed for FGFR3 expression 30 TGCTs and 28 testes containing the tumour precursor cell, carcinoma in situ (CIS). Fetal and adult testes expressed exclusively the FGFR3IIIc isoform. FGFR3 protein expression......Observations in patients with an activating mutation of fibroblast growth factor receptor 3 (FGFR3) suggest a role for FGFR3 signalling in promoting proliferation or survival of germ cells. In this study, we aimed to identify the FGFR3 subtype and the ontogeny of expression during human testis...
15. Application of Jean Piaget's theory of human development for nursing children in an adult intensive therapy unit.
Science.gov (United States)
Green, A
1991-12-01
Piaget (1964) believed that interaction with the environment has a large part to play in human development. Matthew (1986) states that in an ideal world critically ill children should be cared for by staff trained in paediatrics, within designated paediatric intensive therapy units. Unfortunately, there are only 28 paediatric intensive therapy units in Great Britain (CMA Medical Data, 1987), consequently each year a third of children requiring intensive care are admitted to adult intensive therapy units (ITU). A knowledge and understanding of developmental psychology can therefore be beneficial to nurses in assessing which stage of development a child has reached, in order to plan the correct level of stimulation, and hence facilitate progress rather than regression in the accomplishment of developmental tasks. The psychological and social processes involved in Jean Piaget's (1896-1980) theory of human development are discussed with regard to nursing children requiring intubation and ventilation in an adult ITU. PMID:1765639
16. Cross-species variation in gaze following and conspecific preference among great apes, human infants and adults
OpenAIRE
Kano, Fumihiro; Call, Josep
2014-01-01
Although previous studies have shown that many species follow gaze, few have directly compared closely related species, and thus its cross-species variation remains largely unclear. In this study, we compared three great ape species (bonobos, Pan paniscus, chimpanzees, Pan troglodytes, orang-utans, Pongo abelii) and humans (12-month-olds and adults) in their gaze-following responses to the videos of conspecific and allospecific models. In the video, the model turned his head repeatedly to one...
17. Development and application of human adult stem or progenitor cell organoids
NARCIS (Netherlands)
Rookmaaker, Maarten B; Schutgens, Frans; Verhaar, Marianne C; Clevers, Hans
2015-01-01
Adult stem or progenitor cell organoids are 3D adult-organ-derived epithelial structures that contain self-renewing and organ-specific stem or progenitor cells as well as differentiated cells. This organoid culture system was first established in murine intestine and subsequently developed for sever
18. Adult Continuing Education and Human Resource Development: Present Competitors, Potential Partners
Science.gov (United States)
Smith, Douglas H.
2013-01-01
"Author's Note": In May 1989, this article was published in "Livelong Learning," the monthly practitioner journal of the American Association for Adult and Continuing Education (Vol. 12, No. 7, pp. 13-17). Now viewed as a period reference article, it presents the relationship of adult and continuing education (ACE) and…
19. Human adult stem cells from diverse origins: an overview from multiparametric immunophenotyping to clinical applications.
Science.gov (United States)
Sousa, Bruna R; Parreira, Ricardo C; Fonseca, Emerson A; Amaya, Maria J; Tonelli, Fernanda M P; Lacerda, Samyra M S N; Lalwani, Pritesh; Santos, Anderson K; Gomes, Katia N; Ulrich, Henning; Kihara, Alexandre H; Resende, Rodrigo R
2014-01-01
Stem cells are known for their capacity to self-renew and differentiate into at least one specialized cell type. Mesenchymal stem cells (MSCs) were isolated initially from bone marrow but are now known to exist in all vascularized organ or tissue in adults. MSCs are particularly relevant for therapy due to their simplicity of isolation and cultivation. The International Society for Cellular Therapy (ISCT) has proposed a set of standards to define hMSCs for laboratory investigations and preclinical studies: adherence to plastic in standard culture conditions; in vitro differentiation into osteoblasts, adipocytes, and chondroblasts; specific surface antigen expression in which ≥95% of the cells express the antigens recognized by CD105, CD73, and CD90, with the same cells lacking (≤2% positive) the antigens CD45, CD34, CD14 or CD11b, CD79a or CD19, and HLA-DR. In this review we will take an historical overview of how umbilical cord blood, bone marrow, adipose-derived, placental and amniotic fluid, and menstrual blood stem cells, the major sources of human MSC, can be obtained, identified and how they are being used in clinical trials to cure and treat a very broad range of conditions, including heart, hepatic, and neurodegenerative diseases. An overview of protocols for differentiation into hepatocytes, cardiomyocytes, neuronal, adipose, chondrocytes, and osteoblast cells are highlighted. We also discuss a new source of stem cells, induced pluripotent stem cells (iPS cells) and some pathways, which are common to MSCs in maintaining their pluripotent state. PMID:24700575
20. Hybrid mathematical model of cardiomyocyte turnover in the adult human heart.
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Jeremy A Elser
Full Text Available RATIONALE: The capacity for cardiomyocyte regeneration in the healthy adult human heart is fundamentally relevant for both myocardial homeostasis and cardiomyopathy therapeutics. However, estimates of cardiomyocyte turnover rates conflict greatly, with a study employing C14 pulse-chase methodology concluding 1% annual turnover in youth declining to 0.5% with aging and another using cell population dynamics indicating substantial, age-increasing turnover (4% increasing to 20%. OBJECTIVE: Create a hybrid mathematical model to critically examine rates of cardiomyocyte turnover derived from alternative methodologies. METHODS AND RESULTS: Examined in isolation, the cell population analysis exhibited severe sensitivity to a stem cell expansion exponent (20% variation causing 2-fold turnover change and apoptosis rate. Similarly, the pulse-chase model was acutely sensitive to assumptions of instantaneous incorporation of atmospheric C14 into the body (4-fold impact on turnover in young subjects while numerical restrictions precluded otherwise viable solutions. Incorporating considerations of primary variable sensitivity and controversial model assumptions, an unbiased numerical solver identified a scenario of significant, age-increasing turnover (4-6% increasing to 15-22% with age that was compatible with data from both studies, provided that successive generations of cardiomyocytes experienced higher attrition rates than predecessors. CONCLUSIONS: Assignment of histologically-observed stem/progenitor cells into discrete regenerative phenotypes in the cell population model strongly influenced turnover dynamics without being directly testable. Alternatively, C14 trafficking assumptions and restrictive models in the pulse-chase model artificially eliminated high-turnover solutions. Nevertheless, discrepancies among recent cell turnover estimates can be explained and reconciled. The hybrid mathematical model provided herein permits further examination of
1. Nanosized fibers' effect on adult human articular chondrocytes behavior
Energy Technology Data Exchange (ETDEWEB)
Stenhamre, Hanna [Biopolymer Technology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg (Sweden); Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg (Sweden); Thorvaldsson, Anna, E-mail: [email protected] [Biopolymer Technology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg (Sweden); Swerea IVF, Mölndal (Sweden); Enochson, Lars [Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg (Sweden); Walkenström, Pernilla [Swerea IVF, Mölndal (Sweden); Lindahl, Anders [Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg (Sweden); Brittberg, Mats [Cartilage Research Unit, University of Gothenburg, Department Orthopaedics, Kungsbacka Hospital, Kungsbacka (Sweden); Gatenholm, Paul [Biopolymer Technology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg (Sweden)
2013-04-01
Tissue engineering with chondrogenic cell based therapies is an expanding field with the intention of treating cartilage defects. It has been suggested that scaffolds used in cartilage tissue engineering influence cellular behavior and thus the long-term clinical outcome. The objective of this study was to assess whether chondrocyte attachment, proliferation and post-expansion re-differentiation could be influenced by the size of the fibers presented to the cells in a scaffold. Polylactic acid (PLA) scaffolds with different fiber morphologies were produced, i.e. microfiber (MS) scaffolds as well as nanofiber-coated microfiber scaffold (NMS). Adult human articular chondrocytes were cultured in the scaffolds in vitro up to 28 days, and the resulting constructs were assessed histologically, immunohistochemically, and biochemically. Attachment of cells and serum proteins to the scaffolds was affected by the architecture. The results point toward nano-patterning onto the microfibers influencing proliferation of the chondrocytes, and the overall 3D environment having a greater influence on the re-differentiation. In the efforts of finding the optimal scaffold for cartilage tissue engineering, studies as the current contribute to the knowledge of how to affect and control chondrocytes behavior. - Highlights: ► Chondrocyte behavior in nanofiber-coated microfiber versus microfiber scaffolds ► High porosity (> 90%) and large pore sizes (a few hundred μm) of nanofibrous scaffolds ► Proliferation enhanced by presence of nanofibers ► Differentiation not significantly affected ► Cell attachment improved in presence of both nanofibers and serum.
2. MRI manifestations of thymus in myasthenia gravis (MG) patients in various age groups
International Nuclear Information System (INIS)
Objective: To study MRI findings of the thymus in patients with myasthenia gravis (MG) in different age groups and to analyze the relationship between the morphological changes of thymus and the MG. Methods: In total 90 patients with MG (male: female=43:47) received MR scan and were divided into four groups (group A, B, C and D) by age. Fourteen patients out of 90 received additional enhanced scan. Group A included 33 patients aged under 10 years (m:f=18:15); 27 patients aged 11-25 years were in group B (m:f=12:15); group C had 17 patients aged 26-50 years (m:f=6:11); and in group D there were 13 patients whose ages were over 51 years (m:f=7:6). And 30 Non-MG patients aged 8-75 years were selected as control group, in which the thickness, the fat collection, and glandulous atrophy of thymus was studied on CT. Results: 1) The thymus was unremarkable in 44 cases out of 90 (48.88%). 2) Enlarged thymus was shown in 42 cases out of 90 (46.66%), in which non-nodular enlargement was revealed in 34 cases and nodular enlargement in 8 cases. There were 27 cases with abnormality of thymus out of 33 (81.81%) in group A, 12 cases out of 27 (44.44%) in group B and 3 cases in group C, but no abnormality was found in group D. 3) Only 4/90 patients (4.44%) had thymic mass that respectively seen in one case of group B, two of group C and one of group D. No evidence of the involvement of the adjacent structure was found on MRI in the cases of thymic mass. No thymus enlargement was revealed in control group. Fat collection in thymus was seen in both study groups and control group. Conclusion: Intimate relationship between the abnormality of the thymus gland and MG exists in children and teenagers. While in the middle-aged patients or the seniors, further studies should be made to find out whether there is a correlation
3. Experimental investigation of an indirect-mode forced convection solar dryer for drying thymus and mint
International Nuclear Information System (INIS)
Graphical abstract: Photograph of the experimental set-up. - Highlights: • Thermal performance of an indirect-mode solar dryer is investigated. • Mathematical models are obtained for thin layer drying of thymus and mint. • Both thymus and mint show the constant and falling rate drying periods. - Abstract: An indirect-mode forced convection solar dryer was designed and fabricated. The thermal performance of the solar dryer under Tanta (latitude, 30° 47′ N and longitude, 31° E) prevailing weather conditions was experimentally investigated. The system consists of a double pass v-corrugated plate solar air heater connected to a drying chamber. A blower was used to force the heated air to the drying chamber. Drying experiments were performed for thymus (initial moisture content 95% on wet basis) and mint (initial moisture content 85% on wet basis) at an initial temperature of 29 °C. The final moisture contents for thymus and mint were reached after 34 and 5 h, respectively. Fourteen mathematical models of thin layer drying were tested to specify the suitable model for describing the drying behavior of the studied products. It was found that, Midilli and Kucuk model is convenient to describe the thin layer solar drying of mint. However, the Page and modified Page models were found to be the best among others for describing the drying curves of thymus
4. Protecting Effects of Dexamethasone on Thymus of Rats with Severe Acute Pancreatitis
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Tian Hua
2007-12-01
Full Text Available Purpose. To study the protecting effects of dexamethasone on thymus of rats with severe acute pancreatitis (SAP. Methods. The SAP rats were randomly assigned to the model group and dexamethasone-treated group, the other normal healthy rats were assigned to the sham operation group. The rat survival, thymus pathological changes, apoptotic index, as well as expression levels of NF-κB, P-selectin, Bax, Bcl-2, and Caspase-3 protein of all groups were observed, respectively, at 3 hours, 6 hours, and 12 hours. The contents of amylase and endotoxin in plasma as well as the contents of TNF-α, PLA2, and NO in serum were determined. Results. There was no marked difference between the model group and treated group in survival. The contents of different indexes in blood of treated group were lower than those of the model group to various degrees at different time points. The thymus pathological score was lower in treated group than in model group at 12 hours.The treated group in Caspase-3 protein expression of thymus significantly exceeded the model group at 12 hours. The apoptotic index was significantly higher in treated group than in model group. Conclusion. Dexamethasone has protecting effects on thymus of SAP rats.
5. Molluscicidal and Mosquitocidal activities of the essential oils of Thymus capitatus Hoff. et Link. and Marrubium vulgare L.
Science.gov (United States)
Salama, Maha M; Taher, Eman E; El-Bahy, Mohamed M
2012-01-01
Steam distillation of essential oils of aerial parts of Thymus capitatus and Marrubium vulgare L. collected at North cost of Egypt yielded 0.5% and 0.2%, respectively. Results of Gas chromatography-mass spectrometry analyses of the two samples identified 96.27% and 90.19% of the total oil composition for T. capitatus and M. vulgare, respectively. The two oil samples appeared dominated by the oxygenated constituents (88.22% for T. capitatus and 57.50% for M. vulgare), composed of phenols, mainly carvacrol (32.98%) and thymol (32.82%) in essential oil of T. capitatus, and thymol (34.55%) in essential oil of M. vulgare. It was evaluated the molluscicidal activity of T. capitatus and M. vulgare essential oils on adult and eggs of Biomphalaria alexandrina as well as their mosquitocidal activity on Culex pipiens. The LC50 and LC90 of T. capitatus essential oil against adult snails was 200 and 400 ppm/3hrs, respectively, while for M. vulgare it was 50 and 100 ppm/3hrs, respectively. Moreover, M. vulgare showed LC100 ovicidal activity at 200 ppm/24 hrs while T. capitatus oil showed no ovicidal activity. It was verified mosquitocidal activity, with LC50 and LC90 of 100 and 200 ppm/12hrs respectively for larvae, and 200 and 400 ppm/12hrs respectively for pupae of C. pipiens. PMID:22983292
6. Molluscicidal and Mosquitocidal Activities of the Essential oils of Thymus capitatus Hoff. et Link. and Marrubium vulgare L.
Directory of Open Access Journals (Sweden)
Maha M. Salama
2012-10-01
Full Text Available Steam distillation of essential oils of aerial parts of Thymus capitatus and Marrubium vulgare L. collected at North cost of Egypt yielded 0.5% and 0.2%, respectively. Results of Gas chromatography-mass spectrometry analyses of the two samples identified 96.27% and 90.19% of the total oil composition for T. capitatus and M. vulgare, respectively. The two oil samples appeared dominated by the oxygenated constituents (88.22% for T. capitatus and 57.50% for M. vulgare, composed of phenols, mainly carvacrol (32.98% and thymol (32.82% in essential oil of T. capitatus, and thymol (34.55% in essential oil of M. vulgare. It was evaluated the molluscicidal activity of T. capitatus and M. vulgare essential oils on adult and eggs of Biomphalaria alexandrina as well as their mosquitocidal activity on Culex pipiens. The LC50 and LC90 of T. capitatus essential oil against adult snails was 200 and 400 ppm/3hrs, respectively, while for M. vulgare it was 50 and 100 ppm/3hrs, respectively. Moreover, M. vulgare showed LC100 ovicidal activity at 200 ppm/24 hrs while T. capitatus oil showed no ovicidal activity. It was verified mosquitocidal activity, with LC50 and LC90 of 100 and 200 ppm/12hrs respectively for larvae, and 200 and 400 ppm/12hrs respectively for pupae of C. pipiens.
7. Sensitive Tumorigenic Potential Evaluation of Adult Human Multipotent Neural Cells Immortalized by hTERT Gene Transduction
Science.gov (United States)
Jeong, Da Eun; Kim, Sung Soo; Song, Hye Jin; Pyeon, Hee Jang; Kang, Kyeongjin; Hong, Seung-Cheol; Nam, Do-Hyun; Joo, Kyeung Min
2016-01-01
Stem cells and therapeutic genes are emerging as a new therapeutic approach to treat various neurodegenerative diseases with few effective treatment options. However, potential formation of tumors by stem cells has hampered their clinical application. Moreover, adequate preclinical platforms to precisely test tumorigenic potential of stem cells are controversial. In this study, we compared the sensitivity of various animal models for in vivo stem cell tumorigenicity testing to identify the most sensitive platform. Then, tumorigenic potential of adult human multipotent neural cells (ahMNCs) immortalized by the human telomerase reverse transcriptase (hTERT) gene was examined as a stem cell model with therapeutic genes. When human glioblastoma (GBM) cells were injected into adult (4–6-week-old) Balb/c-nu, adult NOD/SCID, adult NOG, or neonate (1–2-week-old) NOG mice, the neonate NOG mice showed significantly faster tumorigenesis than that of the other groups regardless of intracranial or subcutaneous injection route. Two kinds of ahMNCs (682TL and 779TL) were primary cultured from surgical samples of patients with temporal lobe epilepsy. Although the ahMNCs were immortalized by lentiviral hTERT gene delivery (hTERT-682TL and hTERT-779TL), they did not form any detectable masses, even in the most sensitive neonate NOG mouse platform. Moreover, the hTERT-ahMNCs had no gross chromosomal abnormalities on a karyotype analysis. Taken together, our data suggest that neonate NOG mice could be a sensitive animal platform to test tumorigenic potential of stem cell therapeutics and that ahMNCs could be a genetically stable stem cell source with little tumorigenic activity to develop regenerative treatments for neurodegenerative diseases. PMID:27391353
8. Continuous activation of the CD122/STAT-5 signaling pathway during selection of antigen-specific regulatory T cells in the murine thymus.
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Jérémie D Goldstein
Full Text Available Signaling events affecting thymic selection of un-manipulated polyclonal natural CD25(+foxp3(+ regulatory T cells (nTreg have not been established ex vivo. Here, we report a higher frequency of phosphorylated STAT-5 (pSTAT-5 in nTreg cells in the adult murine thymus and to a lesser extent in the periphery, compared to other CD4(+CD8(- subsets. In the neonatal thymus, the numbers of pSTAT-5(+ cells in CD25(+foxp3(- and nTreg cells increased in parallel, suggesting that pSTAT-5(+CD25(+foxp3(- cells might represent the precursors of foxp3(+ regulatory T cells. This "specific" pSTAT-5 expression detected in nTreg cells ex vivo was likely due to a very recent signal given by IL-2/IL-15 cytokines in vivo since (i it disappeared rapidly if cells were left unstimulated in vitro and (ii was also observed if total thymocytes were stimulated in vitro with saturating amounts of IL-2 and/or IL-15 but not IL-7. Interestingly, STAT-5 activation upon IL-2 stimulation correlated better with foxp3 and CD122 than with CD25 expression. Finally, we show that expression of an endogenous superantigen strongly affected the early Treg cell repertoire but not the proportion of pSTAT-5(+ cells within this repertoire. Our results reveal that continuous activation of the CD122/STAT-5 signaling pathway characterize regulatory lineage differentiation in the murine thymus.
9. Thymus transplantation and disease prevention in the diabetes-prone Bio-Breeding rat
International Nuclear Information System (INIS)
Bio-Breeding rat T lymphocytes proliferate poorly in response to alloantigen. Transplantation of Bio-Breeding rats with fetal thymus tissue from diabetes resistant rats leads to an improvement in the T cell proliferative response, but only if the thymus contains bone marrow-derived, radiation-resistant thymic antigen presenting cells of the diabetes-resistant phenotype. The current study provides evidence that thymus transplantation leading to the restoration of Bio-Breeding T cell proliferative function can also significantly reduce the incidence of insulitis and prevent the development of diabetes. It appears that a defect in the bone marrow-derived thymic APC population contributes to an abnormal maturation of Bio-Breeding T lymphocytes which in turn predisposes animals to insulitis and diabetic disease
10. Identification and Characterization of a Novel Thymus Aging Related Protein Rwddl
Institute of Scientific and Technical Information of China (English)
Ning Kang; Wei He; Lian Duan; Long Tang; Shirong Liu; Chunman Li; Yonghai Li; Qingfeng Liu; Yu Hu; Lianxian Cui
2008-01-01
By using DDRT-PCR and EST segment ligation, a novel mouse thymus involution related gene Rwddl was identified. The reading frame encoded a protein of 243 amino acid residues which contained an RWD domain at the N terminus. Rwddl expression in thymus was decreased in aged and oxidatively stressed mice. It was found to be expressed extensively in thymocytes and thymic epithelial cells. The expression level of Rwddl could affect the transactivation activity of androgen receptor (AR) in transiently transfected thymic epithelial cells. However, no direct interaction could be detected by fluorescence resonance energy transfer (FRET) analysis. In conclusion, Rwddl is a thymus involution related protein that may indirectly affect AR signaling pathway. Cellular & Molecular Immunology. 2008;5(4):279-285.
11. Binding of /sup 125/I alpha-bungarotoxin to the thymus of mice
Energy Technology Data Exchange (ETDEWEB)
Ohshima, F.; Kondo, K.; Tsubaki, T.
1978-01-01
Alpha-bungarotoxin is known to bind with nicotinic acetylcholine receptors of skeletal muscle. Binding of iodine 125-labeled alpha bungarotoxin to the murine thymus, muscle, and liver was estimated. The toxin was bound to the muscle. The thymus was also capable of binding a considerable amount of the toxin, and the binding was obviously blocked by tubocurarine chloride. Binding to the liver, an organ containing no nicotinic acetylcholine receptor, was very slight. These results may indicate the presence of nicotinic acetylcholine receptors in the thymus, which could have implications in the pathogenesis of myasthenia gravis. Degenerating myoid cells and their receptors may represent autoantigens that induce an immunological cross-reaction with the receptors of skeletal muscles, giving rise to myasthenia gravis.
12. Age-related changes in the thymus gland: CT-pathologic correlation
Energy Technology Data Exchange (ETDEWEB)
Moore, A.V.; Korobkin, M.; Olanow, W.; Heaston, D.K.; Ram, P.C.; Dunnick, N.R.; Silverman, P.M.
1983-08-01
Recent reports suggest that computed tomography (CT) is useful for thymoma detection in patients with myasthenia gravis. However, that usefulness may be conditioned by the state of the normal thymus. To examine this concept, the CT findings in 64 consecutive patients with histologic confirmation of thymic status after thymectomy or thymic biopsy during mediastinal exploration were reviewed. The normal thymus has a bilobed, arrowhead-shaped cross section at all ages, with gradual focal or diffuse fatty infiltration of the parenchyma usually occurring between 20 and 40 years of age. A thymoma is usually a spherical or oval mass, often producing a focal, distinct bulge in the adjacent pleural reflection. The differentiation of thymoma from normal thymus should be possible in most patients if age-related changes in the normal gland are appreciated.
13. Arterial supply of the thoracic lobes of the thymus in dogs of the Great Dane race.
Directory of Open Access Journals (Sweden)
Rosana Marques Silva
2007-09-01
Full Text Available The origins, numbers and type of arterial branches responsible for the blood supply of thoracic lobes of the thymus were studied in 28 stillborn dogs of the Great Dane, of which 18 were males and 10 were females. The arterial systems of these animals were filled with aqueous solution of Neoprene Latex “450”, 50%. After, the specimens were fixed in 10% formaldehyde aqueous solution. The lobes of the thymus were supplied by direct or indirect arterial branches coming from the right and left internal thoracic arteries, pericardiacophrenicas arteries, right and left costocervicais trunks, and left subclavian artery. The left subclavian artery and brachiocephalic trunk emitted direct branches towards the left thoracic lobe of the thymus.
14. Programming of neuroendocrine self in the thymus and its defect in the development of neuroendocrine autoimmunity
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VincentGeenen
2013-10-01
Full Text Available For centuries after its first description by Galen, the thymus was considered as only a vestigial endocrine organ until the discovery in 1961 by Jacques FAP Miller of its essential role in the development of T (thymo-dependent lymphocytes. A unique thymus first appeared in cartilaginous fishes some 500 million years ago, at the same time or shortly after the emergence of the adaptive (acquired immune system. The thymus may be compared to a small brain or a computer highly specialized in the orchestration of central immunological self-tolerance. This was a necessity for the survival of species, given the potent evolutionary pressure imposed by the high risk of autotoxicity inherent in the stochastic generation of the diversity of immune cell receptors that characterize the adaptive immune response. A new paradigm of ‘neuroendocrine self-peptides’ has been proposed, together with the definition of ‘neuroendocrine self’. Neuroendocrine self-peptides are secreted by thymic epithelial cells (TECs not according to the classic model of neuroendocrine signaling, but are processed for presentation by, or in association with, the thymic major histocompatibility complex (MHC proteins. The autoimmune regulator (AIRE gene/protein controls the transcription of neuroendocrine genes in TECs. The presentation of self-peptides in the thymus is responsible for the clonal deletion of self-reactive T cells, which emerge during the random recombination of gene segments that encode variable parts of the T cell receptor for the antigen (TCR. At the same time, self-antigen presentation in the thymus generates regulatory T (Treg cells that can inhibit, in the periphery, those self-reactive T cells that escaped negative selection in the thymus. Several arguments indicate that the origin of autoimmunity directed against neuroendocrine glands results primarily from a defect in the intrathymic programming of self-tolerance to neuroendocrine functions. This defect may
15. Calf thymus histone H1 is a recombinase that catalyzes ATP-independent DNA strand transfer.
OpenAIRE
Kawasaki, I; Sugano, S; Ikeda, H.
1989-01-01
An activity that catalyzes the strand transfer from linear double-stranded tetracycline-resistance gene (tetr) DNA to circular M13mp8-tetr viral DNA was detected in a crude extract from calf thymus. This activity was purified to near, if not complete, homogeneity as judged by NaDodSO4/polyacrylamide gel electrophoresis. We have tentatively named this protein calf thymus strand-transfer protein 1 (CTST1). The apparent molecular mass of the protein was 35 kDa by gel electrophoresis. Its sedimen...
16. Importance of thymus and its humoral factors in radiation syndrome treatment
International Nuclear Information System (INIS)
The high radiosensitivity is emphasised of lymphoid tissues and of the immunological response of the organism. The red--uced immunity of the irradiated organism even after sublethal doses lasts for a number of months. The thymus is not only an important lymphoid organ but it also secerns hormones having lymph-stimulating effects. The shielding of the thymus during irradiation or the application of thymosine favourably affected in gamma or X-ray irradiated mice not only the regeneration of damaged lymphoid tissues and of immunological response but also the regeneration of blood formation. (A.K.)
17. Copper induced immunotoxicity promote differential apoptotic pathways in spleen and thymus
International Nuclear Information System (INIS)
Highlights: ► Copper-induced ROS generation and mitochondrial trans-membrane potential changes result in different consequences in spleen and thymus. ► Inflammation appeared in both the spleen and thymus after to copper treatment. ► Apoptosis in the spleen appears to follow a p53-independent pathway. ► Apoptosis in the thymus appears to follow a p53-dependent intrinsic and extrinsic pathway. ► In both the spleen and thymus, the CD4+ T cell population decreased and CD8+ T cell population increased after copper treatment. - Abstract: Inorganic copper, such as that in drinking water and copper supplements, largely bypasses the liver and enters the free copper pool of the blood directly and that promote immunosuppression. Nevertheless, the signaling pathways underlying copper-induced immune cell death remains largely unclear. According to our previous in vivo report, to evaluate the further details of the apoptotic mechanism, we have investigated how copper regulates apoptotic pathways in spleen and thymus. We have analyzed different protein expression by western blotting and immunohistochemistry and mRNA expression by RT-PCR and gel electrophoresis. We also have measured mitochondrial trans-membrane potential, ROS and CD4+ and CD8+ population by flow cytometry. Sub lethal doses of copper in spleen and thymus of in vivo Swiss albino mice promote different apoptotic pathways. In case of spleen, ROS generation and mitochondrial trans-membrane potential changes promotes intrinsic pathway of apoptosis that was p53 independent, ultimately leads to decrease in CD4+ T cell population and increase in CD8+ T cell population. However in case of thymus, ROS generation and mitochondrial trans-membrane potential changes lead to death receptor that regulate extrinsic and intrinsic pathways of apoptosis and the apoptotic mechanism which was p53 dependent. Due to copper treatment, thymic CD4+ T cell population decreased and CD8+ T cell population was increased or
18. The influence of gamma-radiation on proliferation activity of combial epithelium in thymus stromal cell culture
International Nuclear Information System (INIS)
A study was made of the effect of gamma-radiation on proliferation of thymus stroms epithelial of newborn mice. EC proliferation was assessed 24 and 48 h after gamma-irradiation by studying the mitotic activity of thymus EC and rate of MTT recovery
19. Chemical composition and antioxidative activity of essential oil of Thymus serpyllum L.
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Petrović Slobodan S.
2014-01-01
Full Text Available Wild thyme (Thymus serpyllum L. is a popular remedy regarding both traditional and conventional medicine. It is used as the antiseptic, aromatic, expectorant, stomachic, antispasmodic, carminative and preservative substance. For the purpose of this paper, wild thyme essential oil was isolated from the dried herb T. serpyllum by hydrodistillation. Original semi-industrial distillation device SP-130 performing distillation by water and steam was used for the hydrodistillation of T. serpyllum essential oils. The temperature during the hydrodistillation in the device SP-130 ranged from 100°C - 102°C at atmospheric pressure, and the whole process lasted 5 hours. The isolated essential oil is a liquid of light yellow colour and the odour characteristic of the genus Thymus. Obtained yield of essential oil was 0.08 %, with 65 components identified in the tested essential oil. The most represented chemical groups are sesquiturpene hydrocarbons with 35.1%, and oxygenated sesquiturpenes with 34.8%. The main components of essential oil of T. serpyllum were: trans-nerolidol (24.2%, germacrene D (16.0%, thymol (7.3%, δ-cadinene (3.7% and β-bisabolene (3.3%. The essential oil showed significantly better ability to neutralize DPPH free radicals (IC50 = 0.503 μL / mL compared with synthetic antioxidants BHA and BHT. Synthetic chemical compounds such as BHA and BHT are used in food industry as antioxidants due to their ability to prolong the shelf-life of foodstuffs by protecting them against deterioration caused by oxidation, such as fat rancidity, colour changes, degradation of the flavor and loss of nutrient value. In recent years, there is a considerable interest in finding natural compounds that could replace sinthetic antioxidants because of adverse toxicological reports on many synthetic compounds. Lamiaceae herbs and their essential oils or extracts application has proven to be the effective preservation agents for the extension shelf-life of
20. Repopulation of adult and neonatal mice with human hepatocytes: A chimeric animal model
OpenAIRE
Bissig, Karl-Dimiter; Le, Tam T.; Woods, Niels-Bjarne; Verma, Inder M.
2007-01-01
We report the successful transplantation of human hepatocytes in immunodeficient, fumarylacetoacetate hydrolase-deficient (fah−/−) mice. Engraftment occurs over the entire liver acinus upon transplantation. A few weeks after transplantation, increasing concentrations of human proteins (e.g., human albumin and human C3a) can be measured in the blood of the recipient mouse. No fusion between mouse and human hepatocytes can be detected. Three months after transplantation, up to 20% of the mouse ...
1. Comparison of the Immunogenicity and Reactogenicity of Cervarix and Gardasil Human Papillomavirus Vaccines in HIV-Infected Adults
DEFF Research Database (Denmark)
Nielsen, Lars Toft; Storgaard, Merete; Müller, Martin;
2013-01-01
Objectives. To compare the immunogenicity and reactogenicity of Cervarix(®) or Gardasil(®) Human Papillomavirus (HPV) vaccines in HIV-infected adults.Methods. A double-blind, controlled trial randomizing HIV-positive adults to receive three doses of Cervarix(®) or Gardasil(®) at 0, 1.5 and 6 months.......Results. Ninety-two participants were included in the study. Anti-HPV-18 antibody titers were higher in the Cervarix(®) group compared with the Gardasil(®) group at 7 and 12 months. No significant differences in anti-HPV-16 antibody titers were found among vaccine groups. Among Cervarix(®) vaccinees, women had.......Conclusions. Both vaccines were immunogenic and well tolerated. Compared with Gardasil(®), Cervarix(®) induced superior vaccine responses among HIV-infected women whereas in HIV-infected men the difference in immunogenicity was less pronounced....
2. Herpes simplex virus type-1 and human lymphocytes: virus expression and the response to infection of adult and foetal cells
International Nuclear Information System (INIS)
The growth of Herpes simplex virus type 1 (HSV-1) in human lymphocytes of adult and foetal origin was studied. Virus DNA synthesis, antigen and particle production and the yield of infectious progeny were determined in cultured lymphocytes with or without exposure to stimulating concentrations of the mitogen phytohaemagglutinin and pokeweed mitogen. Separated subpopulations of cells were examined and the conclusion reached that only the stimulated T-lymphoblast was permissive for full virus expression. Stimulation of cell DNA synthesis in response to infection was observed in cultures of adult and foetal lymphocytes under conditions which were non-permissive for virus growth. Morphological change and prolonged culture survival were a feature of foetal lymphocytes exposed to u.v. irradiated HSV-1. (author)
3. Growth Hormone Safety Workshop Position Paper: a critical appraisal of recombinant human growth hormone therapy in children and adults
DEFF Research Database (Denmark)
Allen, David B; Backeljauw, Philippe; Bidlingmaier, Martin;
2015-01-01
mortality, cancer and cardiovascular risk, and the need for long-term surveillance of the increasing number of adults who were treated with rhGH in childhood. Against this backdrop of interest in safety, the European Society of Paediatric Endocrinology (ESPE), the GRS, and the Pediatric Endocrine Society......Recombinant human GH (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that 'for approved indications, GH is safe'; however, the...... statement highlighted a number of areas for on-going surveillance of long-term safety, including cancer risk, impact on glucose homeostasis, and use of high dose pharmacological rhGH treatment. Over the intervening years, there have been a number of publications addressing the safety of rhGH with regard to...
4. Pluripotency of adult stem cells derived from human and rat pancreas
Science.gov (United States)
Kruse, C.; Birth, M.; Rohwedel, J.; Assmuth, K.; Goepel, A.; Wedel, T.
Adult stem cells are undifferentiated cells found within fully developed tissues or organs of an adult individuum. Until recently, these cells have been considered to bear less self-renewal ability and differentiation potency compared to embryonic stem cells. In recent studies an undifferentiated cell type was found in primary cultures of isolated acini from exocrine pancreas termed pancreatic stellate cells. Here we show that pancreatic stellate-like cells have the capacity of extended self-renewal and are able to differentiate spontaneously into cell types of all three germ layers expressing markers for smooth muscle cells, neurons, glial cells, epithelial cells, chondrocytes and secretory cells (insulin, amylase). Differentiation and subsequent formation of three-dimensional cellular aggregates (organoid bodies) were induced by merely culturing pancreatic stellate-like cells in hanging drops. These cells were developed into stable, long-term, in vitro cultures of both primary undifferentiated cell lines as well as organoid cultures. Thus, evidence is given that cell lineages of endodermal, mesodermal, and ectodermal origin arise spontaneously from a single adult undifferentiated cell type. Based on the present findings it is assumed that pancreatic stellate-like cells are a new class of lineage uncommitted pluripotent adult stem cells with a remarkable self-renewal ability and differentiation potency. The data emphasize the versatility of adult stem cells and may lead to a reappraisal of their use for the treatment of inherited disorders or acquired degenerative diseases.
5. Effect of chitosan edible films added with Thymus moroderi and Thymus piperella essential oil on shelf-life of cooked cured ham.
Science.gov (United States)
Ruiz-Navajas, Y; Viuda-Martos, M; Barber, X; Sendra, E; Perez-Alvarez, J A; Fernández-López, J
2015-10-01
The aim of this work was to develop chitosan edible films added with essential oils obtained from two Thymus species, Thymus moroderi (TMEO) and Thymus piperella (TPEO) to determine their application for enhancing safety (antioxidant and antibacterial properties) and shelf-life of cooked cured ham (CCH) stored at 4 °C during 21 days. Addition of TMEO and TPEO into chitosan films decreased the aerobic mesophilic bacteria (AMB) and lactic acid bacteria (LAB) counts in coated cooked cured ham samples as compared with uncoated samples. Both AMB and LAB showed the lowest counts in CCH samples coated with chitosan films added with TPEO at 2 %. In regard to lipid oxidation, the CCH samples coated with chitosan films added with TMEO or TPEO had lower degrees of lipid oxidation than uncoated control samples. Chitosan films added with TPEO at 2 % showed the lowest values. The addition of TPEO or TMEO in chitosan films used as coated in CCH improved their shelf life. PMID:26396394
6. Ectopic Human Fasciola hepatica Infection by an Adult Worm in the Mesocolon.
Science.gov (United States)
Kim, Ah Jin; Choi, Chang Hwan; Choi, Sun Keun; Shin, Yong Woon; Park, Yun-Kyu; Kim, Lucia; Choi, Suk Jin; Han, Jee Young; Kim, Joon Mee; Chu, Young Chae; Park, In Suh
2015-12-01
We report here an ectopic case of Fasciola hepatica infection confirmed by recovery of an adult worm in the mesocolon. A 56-year-old female was admitted to our hospital with discomfort and pain in the left lower quadrant of the abdomen. Abdominal CT showed 3 abscesses in the left upper quadrant, mesentery, and pelvic cavity. On surgical exploration, abscess pockets were found in the mesocolon of the sigmoid colon and transverse colon. A leaf-like worm found in the abscess pocket of the mesocolon of the left colon was diagnosed as an adult fluke of F. hepatica. Histologically, numerous eggs of F. hepatica were noted with acute and chronic granulomatous inflammations in the subserosa and pericolic adipose tissues. Conclusively, a rare case of ectopic fascioliasis has been confirmed in this study by the adult worm recovery of F. hepatica in the mesocolon. PMID:26797440
7. Comparative study of the chondrogenic potential of human bone marrow stromal cells, neonatal chondrocytes and adult chondrocytes
Energy Technology Data Exchange (ETDEWEB)
Saha, Sushmita [Biomaterials and Tissue Engineering Group, Leeds Dental Institute, University of Leeds, LS29LU (United Kingdom); Kirkham, Jennifer [Biomineralisation Group, Leeds Dental Institute, University of Leeds, LS29LU (United Kingdom); NIHR Leeds Musculoskeletal Biomedical Research Unit, University of Leeds, Chapel Allerton Hospital, Leeds LS74SA (United Kingdom); Wood, David [Biomaterials and Tissue Engineering Group, Leeds Dental Institute, University of Leeds, LS29LU (United Kingdom); Curran, Stephen [Smith and Nephew Research Centre, YO105DF (United Kingdom); Yang, Xuebin, E-mail: [email protected] [Biomaterials and Tissue Engineering Group, Leeds Dental Institute, University of Leeds, LS29LU (United Kingdom); NIHR Leeds Musculoskeletal Biomedical Research Unit, University of Leeds, Chapel Allerton Hospital, Leeds LS74SA (United Kingdom)
2010-10-22
Research highlights: {yields} This study has characterised three different cell types under conditions similar to those used for autologous chondrocyte implantation (ACI) for applications in cartilage repair/regeneration. {yields} Compared for the first time the chondrogenic potential of neonatal chondrocytes with human bone marrow stromal cells (HBMSCs) and adult chondrocytes. {yields} Demonstrated that adult chondrocytes hold greatest potential for use in ACI based on their higher proliferation rates, lower alkaline phosphatise activity and enhanced expression of chondrogenic genes. {yields} Demonstrated the need for chondroinduction as a necessary pre-requisite to efficient chondrogenesis in vitro and, by extrapolation, for cell based therapy (e.g. ACI or cartilage tissue engineering). -- Abstract: Cartilage tissue engineering is still a major clinical challenge with optimisation of a suitable source of cells for cartilage repair/regeneration not yet fully addressed. The aims of this study were to compare and contrast the differences in chondrogenic behaviour between human bone marrow stromal cells (HBMSCs), human neonatal and adult chondrocytes to further our understanding of chondroinduction relative to cell maturity and to identify factors that promote chondrogenesis and maintain functional homoeostasis. Cells were cultured in monolayer in either chondrogenic or basal medium, recapitulating procedures used in existing clinical procedures for cell-based therapies. Cell doubling time, morphology and alkaline phosphatase specific activity (ALPSA) were determined at different time points. Expression of chondrogenic markers (SOX9, ACAN and COL2A1) was compared via real time polymerase chain reaction. Amongst the three cell types studied, HBMSCs had the highest ALPSA in basal culture and lowest ALPSA in chondrogenic media. Neonatal chondrocytes were the most proliferative and adult chondrocytes had the lowest ALPSA in basal media. Gene expression analysis revealed
8. Comparative study of the chondrogenic potential of human bone marrow stromal cells, neonatal chondrocytes and adult chondrocytes
International Nuclear Information System (INIS)
Research highlights: → This study has characterised three different cell types under conditions similar to those used for autologous chondrocyte implantation (ACI) for applications in cartilage repair/regeneration. → Compared for the first time the chondrogenic potential of neonatal chondrocytes with human bone marrow stromal cells (HBMSCs) and adult chondrocytes. → Demonstrated that adult chondrocytes hold greatest potential for use in ACI based on their higher proliferation rates, lower alkaline phosphatise activity and enhanced expression of chondrogenic genes. → Demonstrated the need for chondroinduction as a necessary pre-requisite to efficient chondrogenesis in vitro and, by extrapolation, for cell based therapy (e.g. ACI or cartilage tissue engineering). -- Abstract: Cartilage tissue engineering is still a major clinical challenge with optimisation of a suitable source of cells for cartilage repair/regeneration not yet fully addressed. The aims of this study were to compare and contrast the differences in chondrogenic behaviour between human bone marrow stromal cells (HBMSCs), human neonatal and adult chondrocytes to further our understanding of chondroinduction relative to cell maturity and to identify factors that promote chondrogenesis and maintain functional homoeostasis. Cells were cultured in monolayer in either chondrogenic or basal medium, recapitulating procedures used in existing clinical procedures for cell-based therapies. Cell doubling time, morphology and alkaline phosphatase specific activity (ALPSA) were determined at different time points. Expression of chondrogenic markers (SOX9, ACAN and COL2A1) was compared via real time polymerase chain reaction. Amongst the three cell types studied, HBMSCs had the highest ALPSA in basal culture and lowest ALPSA in chondrogenic media. Neonatal chondrocytes were the most proliferative and adult chondrocytes had the lowest ALPSA in basal media. Gene expression analysis revealed a difference in the
9. Gastrointestinal absorption of plutonium and uranium in fed and fasted adult baboons and mice: application to humans
International Nuclear Information System (INIS)
Gastrointestinal (GI) absorption values of plutonium and uranium were determined in fed and fasted adult baboons and mice. For both baboons and mice, the GI absorptions of plutonium and uranium were 10 to 20 times higher in 24 h fasted animals than in fed ones. For plutonium, GI absorption values in baboons were almost identical to those in mice for both fed and fasted conditions, and values for fed animals agreed with estimates for humans. For uranium, GI absorption values in fed and fasted baboons were 6 to 7 times higher than those in mice, and agreed well with those fed and fasted humans. For one baboon that was not given its morning meal, plutonium absorption 2 h after the start of the active phase was the same as that in the 24 h fasted animals. In contrast, for baboons that received a morning meal, plutonium absorption did not rise to the value of 24 h fasted baboons even 8 h after the meal. We conclude that GI absorption values for plutonium and uranium in adult baboons are good estimates of the values in humans and that the values for the fasted condition should be used to set standards for oral exposure of persons in the workplace. (author)
10. Migrating neuroblasts in the adult human brain: a stream reduced to a trickle
Institute of Scientific and Technical Information of China (English)
Miriam E van Strien; Simone A van den Berge; Elly M Hol
2011-01-01
It has long been thought that neurogenesis (birth of neurons) in the mammalian brain only occurs while the central nervous system is still developing.Although the first indications to the contrary already appeared in the 1960s,it took more than 30 years for the neuroscience community to accept that the mammalian adult brain also generates new neurons.Today it is completely accepted that neurogenesis occurs in two mammalian adult brain areas,the subventricular zone (SVZ) near the lateral ventricles and the subgranular zone in the hippocampus.
11. CT findings of lymphofollicular thymic hyperplasia in adult myasthenia gravis
International Nuclear Information System (INIS)
Objective: To evaluate the CT findings of lymphofollicular thymic hyperplasia in adult myasthenia gravis (MG). Methods: The CT findings of thymus area of 134 adult patients with lymphofollicular thymic hyperplasia in MG were reviewed, all of them with surgically and histologically proven diagnosis, and compared with the CT findings of 165 normal subjects. Results: In the group of patient, CT showed enlargement of thymus in 31 patients, 5 patients had nodule or mass (3 cm) and 9 patients (6.7%) had normal size thymus with soft-tissue density, it can considered with thymic hyperplasia. The spotty or streak shadow showed in other patients, though it could not be certain diagnosed as thymic hyperplasia, but could not be except it. The thymus area tissue complete replacement by fatty density were not found in patient group. The CT findings of patients had marked difference when compared with group of normal subjects (P<0.01), except the spotty or streak shadows. Conclusion: CT scan is an important method in diagnosing thymic lymphofollicular hyperplasia of MG in adult. (authors)
12. Low/Negative Expression of PDGFR-α Identifies the Candidate Primary Mesenchymal Stromal Cells in Adult Human Bone Marrow
DEFF Research Database (Denmark)
Li, Hongzhe; Ghazanfari, Roshanak; Zacharaki, Dimitra;
2014-01-01
Human bone marrow (BM) contains a rare population of nonhematopoietic mesenchymal stromal cells (MSCs), which are of central importance for the hematopoietic microenvironment. However, the precise phenotypic definition of these cells in adult BM has not yet been reported. In this study, we show...... cells exhibited high levels of genes associated with mesenchymal lineages and HSC supportive function. Moreover, lin(-)/CD45(-)/CD271(+)/CD140a(low/-) cells effectively mediated the ex vivo expansion of transplantable CD34(+) hematopoietic stem cells. Taken together, these data indicate that CD140a is a...
13. Vitamin D status in a Brazilian cohort of adolescents and young adults with perinatally acquired human immunodeficiency virus infection
OpenAIRE
Annie Schtscherbyna; Carla Gouveia; Maria Fernanda Miguens Castelar Pinheiro; Ronir Raggio Luiz; Maria Lucia Fleiuss de Farias; Elizabeth Stankiewicz Machado
2016-01-01
The purpose was to determine the prevalence and related factors of vitamin D (VitD) insufficiency in adolescents and young adults with perinatally acquired human immunodeficiency virus. A cohort of 65 patients (17.6 ± 2 years) at the Federal University of Rio de Janeiro, Brazil, were examined for pubertal development, nutrition, serum parathormone and serum 25-hydroxyvitamin D [s25(OH)D]. s25(OH)D levels < 30 ng/mL (< 75 nmol/L) were defined as VitD insufficiency. CD4+ T-cell counts and viral...
14. Using "The Simpsons" to Teach Humanities with Gen X and Gen Y Adult Students
Science.gov (United States)
Fink, Maxwell A.; Foote, Deborah C.
2007-01-01
Many educators lament the UNESCO study showing that by the time the average teen graduates from high school he or she has spent more than fifteen thousand hours watching television and only eleven thousand in the classroom (Gorebel, 1998). Rather than regretting this "condition," colleges, universities, and educators of adults and children should…
15. Isolation and Culture of Adult Epithelial Stem Cells from Human Skin
OpenAIRE
Guo, Zhiru; Draheim, Kyle; Lyle, Stephen
2011-01-01
The homeostasis of all self-renewing tissues is dependent on adult stem cells. As undifferentiated stem cells undergo asymmetric divisions, they generate daughter cells that retain the stem cell phenotype and transit-amplifying cells (TA cells) that migrate from the stem cell niche, undergo rapid proliferation and terminally differentiate to repopulate the tissue.
16. Defining the role of common variation in the genomic and biological architecture of adult human height
NARCIS (Netherlands)
A.R. Wood (Andrew); T. Esko (Tõnu); J. Yang (Jian); S. Vedantam (Sailaja); T.H. Pers (Tune); S. Gustafsson (Stefan); A.Y. Chu (Audrey Y); K. Estrada Gil (Karol); J. Luan; Z. Kutalik; N. Amin (Najaf); M.L. Buchkovich (Martin); D.C. Croteau-Chonka (Damien); F.R. Day (Felix); Y. Duan (Yanan); M. Fall (Magnus); R.S.N. Fehrmann (Rudolf); T. Ferreira (Teresa); A.U. Jackson (Anne); J. Karjalainen (Juha); K.S. Lo (Ken Sin); A. Locke (Adam); R. Mägi (Reedik); E. Mihailov (Evelin); E. Porcu (Eleonora); J.C. Randall (Joshua); A. Scherag (Andre); A.A.E. Vinkhuyzen (Anna A.); H.J. Westra (Harm-Jan); T.W. Winkler (Thomas W.); T. Workalemahu (Tsegaselassie); J.H. Zhao; D. Absher (Devin); E. Albrecht (Eva); D. Anderson (David); J. Baron (Jeffrey); M. Beekman (Marian); A. Demirkan (Ayşe); G.B. Ehret (Georg); B. Feenstra; M.F. Feitosa (Mary Furlan); K. Fischer (Krista); R.M. Fraser (Ross); A. Goel (Anuj); J. Gong (Jian); A.E. Justice (Anne); S. Kanoni (Stavroula); M.E. Kleber (Marcus); K. Kristiansson; U. Lim (Unhee); V. Lotay (Vaneet); J.C. Lui (Julian C); M. Mangino (Massimo); I.M. Leach (Irene Mateo); M.C. Medina-Gomez (Carolina); M.A. Nalls (Michael); A.S. Dimas (Antigone); C. Palmer (Cameron); D. Pasko (Dorota); S. Pechlivanis (Sonali); I. Prokopenko (Inga); J.S. Ried (Janina); S. Ripke (Stephan); D. Shungin (Dmitry); A. Stancáková (Alena); R.J. Strawbridge (Rona); Y.J. Sung (Yun Ju); T. Tanaka (Toshiko); A. Teumer (Alexander); S. Trompet (Stella); S.W. Van Der Laan (Sander W.); J. van Setten (Jessica); J.V. van Vliet-Ostaptchouk (Jana); Z. Wang (Zhaoming); L. Yengo (Loic); W. Zhang (Weihua); U. Afzal (Uzma); J. Ärnlöv (Johan); G.M. Arscott (Gillian M.); S. Bandinelli (Stefania); A. Barrett (Angela); C. Bellis (Claire); A.J. Bennett (Amanda); C. Berne (Christian); M. Blüher (Matthias); J.L. Bolton (Jennifer); Y. Böttcher (Yvonne); H.A. Boyd; M. Bruinenberg (M.); B.M. Buckley (Brendan M.); S. Buyske (Steven); I.H. Caspersen (Ida H.); P.S. Chines (Peter); R. Clarke (Robert); S. Claudi-Boehm (Simone); M.N. Cooper (Matthew); E.W. Daw (E Warwick); P.A. De Jong (Pim A); J. Deelen (Joris); G. Delgado; J.C. Denny (Josh C); R.A.M. Dhonukshe-Rutten (Rosalie); M. Dimitriou (Maria); A.S.F. Doney (Alex); M. Dörr (Marcus); N. Eklund (Niina); E. Eury (Elodie); L. Folkersen (Lasse); M. Garcia (Melissa); F. Geller (Frank); V. Giedraitis (Vilmantas); A. Go (Attie); H. Grallert (Harald); T.B. Grammer (Tanja B); J. Gräßler (Jürgen); H. Grönberg (Henrik); L.C.P.G.M. de Groot (Lisette); C.J. Groves (Christopher J.); J. Haessler (Jeff); P. Hall (Per); T. Haller (Toomas); G. Hallmans (Göran); M. Hannemann (Mario); C.A. Hartman (Catharina); M. Hassinen (Maija); C. Hayward (Caroline); N.L. Heard-Costa (Nancy); Q. Helmer (Quinta); G. Hemani; A.K. Henders (Anjali); H.L. Hillege (Hans); M.A. Hlatky (Mark); W. Hoffmann (Wolfgang); P. Hoffmann (Per); O.L. Holmen (Oddgeir); J.J. Houwing-Duistermaat (Jeanine); T. Illig (Thomas); A. Isaacs (Aaron); A.L. James (Alan); J. Jeff (Janina); B. Johansen (Berit); A. Johansson (Åsa); G.J. Jolley (Jason); T. Juliusdottir (Thorhildur); M.J. Junttila (Juhani); M.M.L. Kho (Marcia); L. Kinnunen (Leena); N. Klopp (Norman); T. Kocher; W. Kratzer (Wolfgang); P. Lichtner (Peter); L. Lind (Lars); J. Lindström (Jaana); S. Lobbens (Stéphane); M. Lorentzon (Mattias); Y. Lu (Yingchang); V. Lyssenko (Valeriya); P.K. Magnusson (Patrik); A. Mahajan (Anubha); M. Maillard (Marc); W.L. McArdle (Wendy); C.A. McKenzie (Colin A.); S. McLachlan (Stela); P.J. McLaren (Paul J); C. Menni (Cristina); S. Merger (Sigrun); L. Milani (Lili); A. Moayyeri (Alireza); K.L. Monda (Keri); M.A. Morken (Mario); G. Müller (Gabriele); M. Müller-Nurasyid (Martina); A.W. Musk (Arthur); N. Narisu (Narisu); M. Nauck (Matthias); I.M. Nolte (Ilja M.); M.M. Nöthen (Markus); L. Oozageer (Laticia); S. Pilz (Stefan); N.W. Rayner (Nigel William); F. Renström (Frida); N.R. Robertson (Neil R.); L.M. Rose (Lynda M.); R. Roussel (Ronan); S. Sanna (Serena); H. Scharnagl (Hubert); S. Scholtens (Salome); F.R. Schumacher (Fredrick R); H. Schunkert (Heribert); R.A. Scott (Robert); J.S. Sehmi (Joban); T. Seufferlein (Thomas); J. Shi (Jianxin); K. Silventoinen (Karri); J.H. Smit (Johannes H.); G.D. Smith; J. Smolonska (Joanna); A. Stanton (Alice); K. Stirrups (Kathy); D.J. Stott (David J); H.M. Stringham (Heather); J. Sundstrom (Johan); M. Swertz (Morris); A.C. Syvanen; B. Tayo (Bamidele); G. Thorleifsson (Gudmar); J.P. Tyrer (Jonathan); S. Van Dijk (Suzanne); N.M. van Schoor (Natasja); N. van der Velde (Nathalie); D. van Heemst (Diana); F.V.A. Van Oort (Floor V A); S.H.H.M. Vermeulen (Sita); N. Verweij (Niek); J.M. Vonk (Judith M); L. Waite (Lindsay); M. Waldenberger (Melanie); R. Wennauer (Roman); L.R. Wilkens (Lynne R.); C. Willenborg (Christina); T. Wilsgaard (Tom); M.K. Wojczynski (Mary ); A. Wong (Andrew); A. Wright (Alan); Q. Zhang (Qunyuan); D. Arveiler (Dominique); S.J.L. Bakker (Stephan J L); J. Beilby (John); R.N. Bergman (Richard); S.M. Bergmann (Sven); R. Biffar; J. Blangero (John); D.I. Boomsma (Dorret); S.R. Bornstein (Stefan R.); P. Bovet (Pascal); P. Brambilla (Paolo); M.J. Brown (Morris); H. Campbell (Harry); M. Caulfield (Mark); A. Chakravarti (Aravinda); F.S. Collins (Francis); F.S. Collins (Francis); D.C. Crawford (Dana); L.A. Cupples (Adrienne); J. Danesh (John); U. de Faire (Ulf); H.M. den Ruijter (Hester ); R. Erbel (Raimund); J. Erdmann (Jeanette); J. Eriksson; M. Farrall (Martin); E. Ferrannini (Ele); J. Ferrieres (Jean); I. Ford; N.G. Forouhi (Nita); T. Forrester (Terrence); R.T. Gansevoort (Ron); P.V. Gejman (Pablo); C. Gieger (Christian); A. Golay (Alain); R.F. Gottesman (Rebecca); V. Gudnason (Vilmundur); U. Gyllensten (Ulf); D.W. Haas (David W); A.S. Hall (Alistair); T.B. Harris (Tamara B.); A.T. Hattersley (Andrew); A.C. Heath (Andrew C); C. Hengstenberg (Christian); A.A. Hicks (Andrew); L.A. Hindorff (Lucia A); A. Hingorani (Aroon); A. Hofman (Albert); G.K. Hovingh (Kees); S.E. Humphries (Steve E.); S.C. Hunt (Steven); E. Hypponen (Elina); K.B. Jacobs (Kevin); M.-R. Jarvelin (Marjo-Riitta); P. Jousilahti (Pekka); A. Jula (Antti); J. Kaprio (Jaakko); J.J.P. Kastelein (John); M.H. Kayser (Manfred); F. Kee (Frank); S. Keinanen-Kiukaanniemi (Sirkka); L.A.L.M. Kiemeney (Bart); J.S. Kooner (Jaspal S.); C. Kooperberg (Charles); S. Koskinen (Seppo); P. Kovacs (Peter); A. Kraja (Aldi); M. Kumari (Meena); J. Kuusisto (Johanna); T.A. Lakka (Timo); C. Langenberg (Claudia); L. Le Marchand (Loic); T. Lehtimäki (Terho); S. Lupoli (Sara); P.A. Madden; S. Männistö (Satu); P. Manunta (Paolo); A. Marette (Andre'); T.C. Matise (Tara C.); B. McKnight (Barbara); T. Meitinger (Thomas); F.L. Moll (Frans); G.W. Montgomery (Grant W.); A.D. Morris (Andrew); A.P. Morris (Andrew); J.C. Murray (Jeffrey); M. Nelis (Mari); C. Ohlsson (Claes); A.J. Oldehinkel (Albertine); K.K. Ong (Ken K.); W.H. Ouwehand (Willem); G. Pasterkamp (Gerard); A. Peters (Annette); P.P. Pramstaller (Peter Paul); J.F. Price (Jackie F.); L. Qi (Lu); O. Raitakari (Olli); T. Rankinen (Tuomo); D.C. Rao (Dabeeru C.); T.K. Rice (Treva K.); M.D. Ritchie (Marylyn D.); I. Rudan (Igor); V. Salomaa (Veikko); N.J. Samani (Nilesh); J. Saramies (Jouko); M.A. Sarzynski (Mark A.); P.E.H. Schwarz (Peter E. H.); S. Sebert (Sylvain); P. Sever (Peter); A.R. Shuldiner (Alan); J. Sinisalo (Juha); V. Steinthorsdottir (Valgerdur); R.P. Stolk; J.-C. Tardif (Jean-Claude); A. Tönjes (Anke); A. Tremblay (Angelo); E. Tremoli (Elena); J. Virtamo (Jarmo); M.-C. Vohl (Marie-Claude); P. Amouyel (Philippe); F.W. Asselbergs (Folkert W.); T.L. Assimes (Themistocles); M. Bochud (Murielle); B.O. Boehm (Bernhard); E.A. Boerwinkle (Eric); E.P. Bottinger (Erwin P.); C. Bouchard (Claude); S. Cauchi (Stéphane); J.C. Chambers (John C.); S.J. Chanock (Stephen); R.S. Cooper (Richard S.); P.I.W. de Bakker (Paul); G.V. Dedoussis (George); L. Ferrucci (Luigi); P.W. Franks; P. Froguel (Philippe); L. Groop (Leif); C.A. Haiman (Christopher); A. Hamsten (Anders); M.G. Hayes (M. Geoffrey); J. Hui (Jennie); D. Hunter (David); K. Hveem (Kristian); J.W. Jukema (Jan Wouter); R.C. Kaplan (Robert); M. Kivimaki (Mika); D. Kuh (Diana); M. Laakso (Markku); Y. Liu (Yongmei); N.G. Martin (Nicholas); W. März (Winfried); M. Melbye (Mads); S. Moebus (Susanne); P. Munroe (Patricia); I. Njølstad (Inger); B.A. Oostra (Ben); C.N.A. Palmer (Colin); N.L. Pedersen (Nancy L.); M. Perola (Markus); L. Perusse (Louis); U. Peters (Ulrike); J.E. Powell (Joseph); C. Power (Christine); T. Quertermous (Thomas); R. Rauramaa (Rainer); E. Reinmaa (Eva); P.M. Ridker (Paul); F. Rivadeneira Ramirez (Fernando); J.I. Rotter (Jerome I.); T. Saaristo (Timo); D. Saleheen; D. Schlessinger (David); P.E. Slagboom (P Eline); H. Snieder (Harold); T.D. Spector (Timothy); K. Strauch (Konstantin); M. Stumvoll (Michael); J. Tuomilehto (Jaakko); M. Uusitupa (Matti); P. van der Harst (Pim); H. Völzke (Henry); M. Walker (Mark); N.J. Wareham (Nick); H. Watkins (Hugh); H.E. Wichmann (Heinz Erich); J.F. Wilson (James F); P. Zanen (Pieter); P. Deloukas (Panagiotis); I.M. Heid (Iris); C.M. Lindgren (Cecilia); K.L. Mohlke (Karen); E.K. Speliotes (Elizabeth); U. Thorsteinsdottir (Unnur); I. Barroso (Inês); C.S. Fox (Caroline S.); K.E. North (Kari); D.P. Strachan (David P.); J.S. Beckmann (Jacques); S.I. Berndt (Sonja); M. Boehnke (Michael); I.B. Borecki (Ingrid); M.I. McCarthy (Mark); A. Metspalu (Andres); J-A. Zwart (John-Anker); A.G. Uitterlinden (André); C.M. van Duijn (Cock); L. Franke (Lude); C.J. Willer (Cristen); A. Price (Alkes); G. Lettre (Guillaume); R.J.F. Loos (Ruth); M.N. Weedon (Michael); E. Ingelsson (Erik); J.R. O´Connell; G.R. Abecasis (Gonçalo); D.I. Chasman (Daniel); M.E. Goddard (Michael); P.M. Visscher (Peter); J.N. Hirschhorn (Joel); T.M. Frayling (Timothy)
2014-01-01
textabstractUsing genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated 1/42,
17. Defining the role of common variation in the genomic and biological architecture of adult human height
NARCIS (Netherlands)
Wood, Andrew R.; Esko, Tonu; Yang, Jian; Vedantam, Sailaja; Pers, Tune H.; Gustafsson, Stefan; Chun, Audrey Y.; Estrada, Karol; Luan, Jian'an; Kutalik, Zoltan; Amin, Najaf; Buchkovich, Martin L.; Croteau-Chonka, Damien C.; Day, Felix R.; Duan, Yanan; Fall, Tove; Fehrmann, Rudolf; Ferreira, Teresa; Jackson, Anne U.; Karjalainen, Juha; Lo, Ken Sin; Locke, Adam E.; Maegi, Reedik; Mihailov, Evelin; Porcu, Eleonora; Randall, Joshua C.; Scherag, Andre; Vinkhuyzen, Anna A. E.; Westra, Harm-Jan; Winkler, Thomas W.; Workalemahu, Tsegaselassie; Zhao, Jing Hua; Absher, Devin; Albrecht, Eva; Anderson, Denise; Baron, Jeffrey; Beekman, Marian; Demirkan, Ayse; Ehret, Georg B.; Feenstra, Bjarke; Feitosa, Mary F.; Fischer, Krista; Fraser, Ross M.; Goel, Anuj; Gong, Jian; Justice, Anne E.; Kanoni, Stavroula; Kleber, Marcus E.; Kristiansson, Kati; Lim, Unhee; Lotay, Vaneet; Lui, Julian C.; Mangino, Massimo; Mateo Leach, Irene; Medina-Gomez, Carolina; Nalls, Michael A.; Nyholt, Dale R.; Palmer, Cameron D.; Pasko, Dorota; Pechlivanis, Sonali; Prokopenko, Inga; Ried, Janina S.; Ripke, Stephan; Shungin, Dmitry; Stancakova, Alena; Strawbridge, Rona J.; Sung, Yun Ju; Tanaka, Toshiko; Teumer, Alexander; Trompet, Stella; van der Laan, Sander W.; van Setten, Jessica; Van Vliet-Ostaptchouk, Jana V.; Wang, Zhaoming; Yengo, Loic; Zhang, Weihua; Afzal, Uzma; Arnloev, Johan; Arscott, Gillian M.; Bandinelli, Stefania; Barrett, Amy; Bellis, Claire; Bennett, Amanda J.; Berne, Christian; Blueher, Matthias; Bolton, Jennifer L.; Boettcher, Yvonne; Boyd, Heather A.; Bruinenberg, Marcel; Buckley, Brendan M.; Buyske, Steven; Caspersen, Ida H.; Chines, Peter S.; Clarke, Robert; Claudi-Boehm, Simone; Cooper, Matthew; Daw, E. Warwick; De Jong, Pim A.; Deelen, Joris; Delgado, Graciela; Denny, Josh C.; Dhonukshe-Rutten, Rosalie; Dimitriou, Maria; Doney, Alex S. F.; Doerr, Marcus; Eklund, Niina; Eury, Elodie; Folkersen, Lasse; Garcia, Melissa E.; Geller, Frank; Giedraitis, Vilmantas; Go, Alan S.; Grallert, Harald; Grammer, Tanja B.; Graessler, Juergen; Groenberg, Henrik; de Groot, Lisette C. P. G. M.; Groves, Christopher J.; Haessler, Jeffrey; Hall, Per; Haller, Toomas; Hallmans, Goran; Hannemann, Anke; Hartman, Catharina A.; Hassinen, Maija; Hayward, Caroline; Heard-Costa, Nancy L.; Helmer, Quinta; Hemani, Gibran; Henders, Anjali K.; Hillege, Hans L.; Hlatky, Mark A.; Hoffmann, Wolfgang; Hoffmann, Per; Holmen, Oddgeir; Houwing-Duistermaat, Jeanine J.; Illig, Thomas; Isaacs, Aaron; James, Alan L.; Jeff, Janina; Johansen, Bent; Johansson, Asa; Jolley, Jennifer; Juliusdottir, Thorhildur; Junttila, Juhani; Kho, Abel N.; Kinnunen, Leena; Klopp, Norman; Kocher, Thomas; Kratzer, Wolfgang; Lichtner, Peter; Lind, Lars; Lindstroem, Jaana; Lobbens, Stephane; Lorentzon, Mattias; Lu, Yingchang; Lyssenko, Valeriya; Magnusson, Patrik K. E.; Mahajan, Anubha; Maillard, Marc; McArdle, Wendy L.; McKenzie, Colin A.; McLachlan, Stela; McLaren, Paul J.; Menni, Cristina; Merger, Sigrun; Milani, Lili; Moayyeri, Alireza; Monda, Keri L.; Morken, Mario A.; Mueller, Gabriele; Mueller-Nurasyid, Martina; Musk, Arthur W.; Narisu, Narisu; Nauck, Matthias; Nolte, Ilja M.; Noethen, Markus M.; Oozageer, Laticia; Pilz, Stefan; Rayner, Nigel W.; Renstrom, Frida; Robertson, Neil R.; Rose, Lynda M.; Roussel, Ronan; Sanna, Serena; Scharnagl, Hubert; Scholtens, Salome; Schumacher, Fredrick R.; Schunkert, Heribert; Scott, Robert A.; Sehmi, Joban; Seufferlein, Thomas; Shin, Jianxin; Silventoinen, Karri; Smit, Johannes H.; Smith, Albert Vernon; Smolonska, Joanna; Stanton, Alice V.; Stirrups, Kathleen; Stott, David J.; Stringham, Heather M.; Sundstrom, Johan; Swertz, Morris A.; Syvanen, Ann-Christine; Tayo, Bamidele O.; Thorleifsson, Gudmar; Tyrer, Jonathan P.; van Dijk, Suzanne; van Schoor, Natasja M.; van der Velde, Nathalie; van Heemst, Diana; van Oort, Floor V. A.; Vermeulen, Sita H.; Verweij, Niek; Vonk, Judith M.; Waite, Lindsay L.; Waldenberger, Melanie; Wennauer, Roman; Wilkens, Lynne R.; Willenborg, Christina; Wilsgaard, Tom; Wojczynski, Mary K.; Wong, Andrew; Wright, Alan F.; Zhang, Qunyuan; Arveiler, Dominique; Bakker, Stephan J. L.; Beilby, John; Bergman, Richard N.; Bergmann, Sven; Biffar, Reiner; Blangero, John; Boomsma, Dorret I.; Bornstein, Stefan R.; Bovet, Pascal; Brambilla, Paolo; Brown, Morris J.; Campbell, Harry; Caulfield, Mark J.; Chakravarti, Aravinda; Collins, Rory; Collins, Francis S.; Crawford, Dana C.; Cupples, L. Adrienne; Danesh, John; de Faire, Ulf; den Ruijter, Hester M.; Erbel, Raimund; Erdmann, Jeanette; Eriksson, Johan G.; Farrall, Martin; Ferrannini, Ele; Ferrieres, Jean; Ford, Ian; Forouhi, Nita G.; Forrester, Terrence; Gansevoort, Ron T.; Gejman, Pablo V.; Gieger, Christian; Golay, Alain; Gottesman, Omri; Gudnason, Vilmundur; Gyllensten, Ulf; Haas, David W.; Hall, Alistair S.; Harris, Tamara B.; Hattersley, Andrew T.; Heath, Andrew C.; Hengstenberg, Christian; Hicks, Andrew A.; Hindorff, Lucia A.; Hingorani, Aroon D.; Hofman, Albert; Hovingh, G. Kees; Humphries, Steve E.; Hunt, Steven C.; Hypponen, Elina; Jacobs, Kevin B.; Jarvelin, Marjo-Riitta; Jousilahti, Pekka; Jula, Antti M.; Kaprio, Jaakko; Kastelein, John J. P.; Kayser, Manfred; Kee, Frank; Keinanen-Kiukaanniemi, Sirkka M.; Kiemeney, Lambertus A.; Kooner, Jaspal S.; Kooperberg, Charles; Koskinen, Seppo; Kovacs, Peter; Kraja, Aldi T.; Kumari, Meena; Kuusisto, Johanna; Lakka, Timo A.; Langenberg, Claudia; Le Marchand, Loic; Lehtimaki, Terho; Lupoli, Sara; Madden, Pamela A. F.; Mannisto, Satu; Manunta, Paolo; Marette, Andre; Matise, Tara C.; McKnight, Barbara; Meitinger, Thomas; Moll, Frans L.; Montgomery, Grant W.; Morris, Andrew D.; Morris, Andrew P.; Murray, Jeffrey C.; Nelis, Mari; Ohlsson, Claes; Oldehinkel, Albertine J.; Ong, Ken K.; Ouwehand, Willem H.; Pasterkamp, Gerard; Peters, Annette; Pramstaller, Peter P.; Price, Jackie F.; Qi, Lu; Raitakari, Olli T.; Rankinen, Tuomo; Rao, D. C.; Rice, Treva K.; Ritchie, Marylyn; Rudan, Igor; Salomaa, Veikko; Samani, Nilesh J.; Saramies, Jouko; Sarzynski, Mark A.; Schwarz, Peter E. H.; Sebert, Sylvain; Sever, Peter; Shuldiner, Alan R.; Sinisalo, Juha; Steinthorsdottir, Valgerdur; Stolk, Ronald P.; Tardif, Jean-Claude; Toenjes, Anke; Tremblay, Angelo; Tremoli, Elena; Virtamo, Jarmo; Vohl, Marie-Claude; Amouyel, Philippe; Asselbergs, Folkert W.; Assimes, Themistocles L.; Bochud, Murielle; Boehm, Bernhard O.; Boerwinkle, Eric; Bottinger, Erwin P.; Bouchard, Claude; Cauchi, Stephane; Chambers, John C.; Chanock, Stephen J.; Cooper, Richard S.; de Bakker, Paul I. W.; Dedoussis, George; Ferrucci, Luigi; Franks, Paul W.; Froguel, Philippe; Groop, Leif C.; Haiman, Christopher A.; Hamsten, Anders; Hayes, M. Geoffrey; Hui, Jennie; Hunter, David J.; Hveem, Kristian; Jukema, J. Wouter; Kaplan, Robert C.; Kivimaki, Mika; Kuh, Diana; Laakso, Markku; Liu, Yongmei; Martin, Nicholas G.; Maerz, Winfried; Melbye, Mads; Moebus, Susanne; Munroe, Patricia B.; Njolstad, Inger; Oostra, Ben A.; Palmer, Colin N. A.; Pedersen, Nancy L.; Perola, Markus; Perusse, Louis; Peters, Ulrike; Powell, Joseph E.; Power, Chris; Quertermous, Thomas; Rauramaa, Rainer; Reinmaa, Eva; Ridker, Paul M.; Rivadeneira, Fernando; Rotter, Jerome I.; Saaristo, Timo E.; Saleheen, Danish; Schlessinger, David; Slagboom, P. Eline; Snieder, Harold; Spector, Tim D.; Strauch, Konstantin; Stumvoll, Michael; Tuomilehto, Jaakko; Uusitupa, Matti; van der Harst, Pim; Voelzke, Henry; Walker, Mark; Wareham, Nicholas J.; Watkins, Hugh; Wichmann, H-Erich; Wilson, James F.; Zanen, Pieter; Deloukas, Panos; Heid, Iris M.; Lindgren, Cecilia M.; Mohlke, Karen L.; Speliotes, Elizabeth K.; Thorsteinsdottir, Unnur; Barroso, Ines; Fox, Caroline S.; North, Kari E.; Strachan, David P.; Beckmann, Jacques S.; Berndt, Sonja I.; Boehnke, Michael; Borecki, Ingrid B.; McCarthy, Mark I.; Metspalu, Andres; Stefansson, Kari; Uitterlinden, Andre G.; van Duijn, Cornelia M.; Franke, Lude; Willer, Cristen J.; Price, Alkes L.; Lettre, Guillaume; Loos, Ruth J. F.; Weedon, Michael N.; Ingelsson, Erik; O'Connell, Jeffrey R.; Abecasis, Goncalo R.; Chasman, Daniel I.; Goddard, Michael E.; Visscher, Peter M.; Hirschhorn, Joel N.; Frayling, Timothy M.
2014-01-01
Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated similar to 2,000,
18. Defining the role of common variation in the genomic and biological architecture of adult human height
NARCIS (Netherlands)
Wood, A.R.; Esko, T.; Yang, J.; Vedantam, S.; Pers, T.H.; Gustafsson, S.; Chu, A.Y.; Estrada, K.; Luan, J.; Kutalik, Z.; Amin, N.; Buchkovich, M.L.; Croteau-Chonka, D.C.; Day, F.R.; Duan, Y.; Fall, T.; Fehrmann, R.; Ferreira, T.; Jackson, A.U.; Karjalainen, J.; Lo, K.S.; Locke, A.E.; Magi, R.; Mihailov, E.; Porcu, E.; Randall, J.C.; Scherag, A.; Vinkhuyzen, A.A.; Westra, H.J.; Winkler, T.W.; Workalemahu, T.; Zhao, J.H.; Absher, D.; Albrecht, E.; Anderson, D.; Baron, J.; Beekman, M.; Demirkan, A.; Ehret, G.B.; Feenstra, B.; Feitosa, M.F.; Fischer, K.; Fraser, R.M.; Goel, A.; Gong, J.; Justice, A.E.; Kanoni, S.; Kleber, M.E.; Kristiansson, K.; Lim, U.; Lotay, V.; Lui, J.C.; Mangino, M.; Leach, I.M.; Medina-Gomez, C.; Nalls, M.A.; Nyholt, D.R.; Palmer, C.D.; Pasko, D.; Pechlivanis, S.; Prokopenko, I.; Ried, J.S.; Ripke, S.; Shungin, D.; Stancakova, A.; Strawbridge, R.J.; Sung, Y.J.; Tanaka, T.; Teumer, A.; Trompet, S.; Laan, S.W. van der; Setten, J. van; Vliet-Ostaptchouk, J.V. Van; Wang, Z.; Yengo, L.; Zhang, W.; Afzal, U.; Arnlov, J.; Arscott, G.M.; Bandinelli, S.; Barrett, A.; Bellis, C.; Bennett, A.J.; Berne, C.; Bluher, M.; Bolton, J.L.; Bottcher, Y.; Boyd, H.A.; Bruinenberg, M.; Buckley, B.M.; Buyske, S.; Caspersen, I.H.; Chines, P.S.; Clarke, R.; Claudi-Boehm, S.; Cooper, M.; Daw, E.W.; Jong, P.A. de; Deelen, J.; Delgado, G.; Vermeulen, S.; Kiemeney, L.A.
2014-01-01
Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated approximately 2,0
19. Hiding and Searching Strategies of Adult Humans in a Virtual and a Real-Space Room
Science.gov (United States)
Talbot, Katherine J.; Legge, Eric L. G.; Bulitko, Vadim; Spetch, Marcia L.
2009-01-01
Adults searched for or cached three objects in nine hiding locations in a virtual room or a real-space room. In both rooms, the locations selected by participants differed systematically between searching and hiding. Specifically, participants moved farther from origin and dispersed their choices more when hiding objects than when searching for…
20. 21st Century African Philosophy of Adult and Human Resource Education in Southern Africa
Science.gov (United States)
Mutamba, Charlene
2012-01-01
This paper will attempt to define a philosophy of adult education for the purpose of workforce development in Southern Africa. The different influences such as Ubuntu and communalism, indigenous education, diversity western philosophy, globalization and technology are explored in the context of the Southern African region.
1. Generation of human/rat xenograft animal model for the study of human donor stem cell behaviors in vivo
Institute of Scientific and Technical Information of China (English)
Yan Sun; Dong Xiao; Xing-Hua Pan; Ruo-Shuang Zhang; Guang-Hui Cui; Xi-Gu Chen
2007-01-01
AIM: To accurately and realistically elucidate human stem cell behaviors In vivo and the fundamental mechanisms controlling human stem cell fates in vivo, which is urgently required in regenerative medicine and treatments for some human diseases, a surrogate human-rat chimera model was developed.METHODS: Human-rat chimeras were achieved by in utero transplanting low-density mononuclear cells from human umbilical cord blood into the fetal rats at 9-11 d of gestation, and subsequently, a variety of methods, including flow cytometry, PCR as well as immunohistochemical assay, were used to test the human donor contribution in the recipients.RESULTS: Of 29 live-born recipients, 19 had the presence of human CD45+ cells in peripheral blood (PB) detected by flow cytometry, while PCR analysis on genomic DNA from 11 different adult tissues showed that 14 selected from flow cytometry-positive 19 animals possessed of donor-derived human cell engraftment in multiple tissues (i.e. liver, spleen, thymus, heart, kidney, blood, lung, muscle, gut and skin) examined at the time of tissue collection, as confirmed by detecting human β2-microglobulin expression using immunohistochemistry.In this xenogeneic system, the engrafted donor-derived human cells persisted in multiple tissues for at least 6 mo after birth. Moreover, transplanted human donor cells underwent site-specific differentiation into CK18-positive human cells in chimeric liver and CD45-positive human cells in chimeric spleen and thymus of recipients.CONCLUSION: Taken together, these findings suggest that we successfully developed human-rat chimeras, in which xenogeneic human cells exist up to 6 mo later. This humanized small animal model, which offers an in vivo environment more closely resembling to the situations in human, provides an invaluable and effective approach for in vivo investigating human stem cell behaviors, and further in vivo examining fundamental mechanisms controlling human stem cell fates in the future
2. Suppression of a thymus dependent humoral response in mice by Concanavalin A in vivo
International Nuclear Information System (INIS)
Mice treated with Concanavalin A prior to immunization with sheep erthyrocytes exhibit a markedly reduced plaque forming spleen cell response. This immunosuppressive effect could be reversed by using higher doses of antigen or priming the animals with nonimmunizing doses of antigen prior to Concanavalin A injection designed to either by-pass or enhance thymus derived lymphocyte functions. It was also demonstrated that Concanavalin A in vivo activated the thymus derived lymphocyte subpopulation in the spleen, and this activation was dose dependent and correlated with the immunosuppression observed. Animals injected with Concanavalin A at various times prior to whole body lethal irradiation would not support the plaque forming cell response of adoptively transferred normal syngeneic spleen cells. This effect was shown to be time and dose of Concanavalin A dependent. It was also shown that the route of injection of Concanavalin A prior to irradiation determined the results observed, in that the intravenous route resulted in the suppression of transferred cells, while the intraperitoneal route showed no effect. It is suggested that Concanavalin A induced immunosuppression of the humoral, thymus dependent immune response in mice results for the activation of a subpopulation of thymus derived suppressors cells, and that the effect is short lived, radiation resistant, and dose of Concanavalin A and antigen dependent
3. Thymus herba-barona subsp. bivalens, a new endemic taxon from the Balearic Islands
OpenAIRE
Mayol Martínez, Maria; Sáez, Llorenç; Rosselló, Josep Antoni
1998-01-01
Se describe un nuevo taxón (Thymus herba-barona subsp. bivalens) de la zona montañosa de Mallorca que se distingue del tipo por ser diploide (2n=28), presentar hojas glabras (con algunos tricomas pluricelulares en el haz), dientes inferiores del cáliz menores y la longitud del tubo mayor que los dientes calicinales.
4. Ultrasonographic assessment of normal thymus in pediatric patients: Aspects and features
International Nuclear Information System (INIS)
To determine the viewing rate and ultrasound features of normal thymus. We analyzed the thymuses of 60 healthy children using ultrasound. The ages of the children ranged from one month to three years. a 7.5 MHz linear transducer was used in every case. Trans, supra and para sternal approaches were employed to procure sagittal and transverse sections. We analyzed the dimensions of the gland according to age, sex and body surface. We also studied the internal architecture, echogenicity and relation to adjacent mediastinal structures. We were able to study and measure the thymus in its entirety in every case. The examination never took more than 15 minutes. In longitudinal sections, the left lobe had the appearance of a shark fin or sickle and the right lobe was tear-shaped or rhomboid. The size of the thymus did not vary significantly according to age, sex or body surface. Its internal echogenicity was homogeneous. We consider ultrasonography to be an easy, wide available and safe method for examining the features of the thymic gland in children; moreover, it aids in the assessment of suspicious plain chest x-ray images. (Author)
5. Isolation and Structure Elucidation of Radical Scavengers from Thymus vulgaris Leaves
NARCIS (Netherlands)
Dapkevicius, A.; Beek, van T.A.; Lelyveld, G.P.; Veldhuizen, van A.; Groot, de Æ.; Linssen, J.P.H.; Venskutonis, R.
2002-01-01
2,2-Diphenyl-1-picrylhydrazyl radical (DPPH*) scavenging activity-guided fractionation of a leaf extract of Thymus vulgaris led to the isolation of the radical scavengers rosmarinic acid 1, eriodictyol, taxifolin, luteolin 7-glucuronide, p-cymene 2,3-diol, p-cymene 2,3-diol 6-6'-dimer, carvacrol, th
6. Fluorescence study of thymus lymphocytes of X-irradiated mice and their progeny
International Nuclear Information System (INIS)
7. Visualization of the thymus in myasthenia gravis. Comparison between pneumomediastinography and CT of the anterior mediastinum
Energy Technology Data Exchange (ETDEWEB)
Komatsu, Midori; Tanaka, Makoto; Morimatsu, Mitsunori; Hirai, Shunsaku; Heshiki, Atsuko (Gunma Univ., Maebashi (Japan). School of Medicine)
1982-12-01
We investigated whether CT had any advantage over pneumomediastinography (PMG) for the visualization of thymus in twenty-one patients with myasthenia gravis (MG). In two cases of thymoma which had been suspected with chest radiography, CT demonstrated an anterior mediastinal tumor distinguishable from other mediastinal organs, and for these cases PMG was not performed. Excluding three patients who were submitted to PMG only, CT of the anterior mediastinum was carried out in sixteen patients of MG, revealing thymic shadows in seven (44%). PMG followed by conventional tomography was done subsequently in three of these seven cases, for whom thymectomy was indicated because of uncontrollable myasthenic symptoms, and in all patients finger-like thymic shadows were disclosed. The vertical extension of thymus was more easily demonstrable by PMG than CT. PMG was carried out in six of nine patients in whom CT was negative, and in all cases thymic shadows were obvious with subsequent conventional tomography. Consequently, false negative rate of CT was at least 38% (6/16) with regard to the visualization of the nontumorous thymus. Although CT of the anterior mediastinum is useful as a screening method because of its non-invasiveness, its negative result does not rule out an absence of the pathologic thymus in view of its high false negative rate. In this regard, PMG is still necessary for the final determination of the thymic configuration in the MG patients.
8. Thymus endocrine function in acute radiation sickness resulted from Chernobyl accident
International Nuclear Information System (INIS)
Data are presented on the role of inhibition of endocrine function of the thymus in the pathogenesis of acute radiation sickness resulted from the direct and indirect (via the increased glucocorticoid production) effects of ionizing radiation. The complex treatment, including nonspecific active immunotherapy, permitted to normalize the thymic hormone level and certain parameters of the immune system
9. The graft-versus-host reaction and immune function. II. Recruitment of pre-T-cells in vivo by graft-versus-host-induced dysplastic thymuses following irradiation and bone marrow treatment
International Nuclear Information System (INIS)
The graft-versus-host (GVH) reaction induces thymic dysplasia and an arrest in T cell differentiation. Studies were performed to test the effect of irradiation and reconstitution with bone marrow on GVH-induced thymic dysplasia and T cell differentiation. GVH reactions were induced in CBAxAF1 adult mice by the injection of A strain lymphoid cells. All GVH-reactive mice were immunosuppressed by day 7 after GVH induction and thymic dysplasia was evident by day 24. Forty days after the induction of the GVH reaction the mice were irradiated (850 rads) and repopulated with 10-15 X 10(6) syngeneic or parental bone marrow cells. Thirty days after irradiation and bone marrow reconstitution, GVH-reactive mice were used for histological and functional studies. These mice displayed near-normal thymus morphology with scattered epithelial cells in the medulla, and normal numbers of Thy-1-positive cells. Donor cells had totally repopulated thymuses of irradiated bone marrow reconstituted mice by day 19 after irradiation. T helper cell function did not recover in the reconstituted mice. These results suggest that (1) the process responsible for GVH-induced thymic dysplasia is radiosensitive, and (2) the thymus has the potential to regenerate a normal structure, but fails to regain normal function
10. Developmental changes of prefrontal activation in humans: a near-infrared spectroscopy study of preschool children and adults.
Directory of Open Access Journals (Sweden)
Yuki Kawakubo
11. Detection of human bocavirus from children and adults with acute respiratory tract illness in Guangzhou, southern China
Directory of Open Access Journals (Sweden)
Liu Wen-Kuan
2011-12-01
Full Text Available Abstract Background Human bocavirus (HBoV is a newly discovered parvovirus associated with acute respiratory tract illness (ARTI and gastrointestinal illness. Our study is the first to analyze the characteristics of HBoV-positive samples from ARTI patients with a wide age distribution from Guangzhou, southern China. Methods Throat swabs (n=2811 were collected and analyzed from children and adults with ARTI over a 13-month period. The HBoV complete genome from a 60 year-old female patient isolate was also determined. Results HBoV DNA was detected in 65/2811 (2.3% samples, of which 61/1797 were from children (Mycoplasma pneumoniae had the highest frequency of 16.9% (11/65. Upper and lower respiratory tract illness were common symptoms, with 19/65 (29.2% patients diagnosed with pneumonia by chest radiography. All four adult patients had systemic influenza-like symptoms. Phylogenetic analysis of the complete genome revealed a close relationship with other HBoVs, and a more distant relationship with HBoV2 and HBoV3. Conclusions HBoV was detected from children and adults with ARTI from Guangzhou, southern China. Elderly people were also susceptive to HBoV. A single lineage of HBoV was detected among a wide age distribution of patients with ARTI.
12. Risk factors for perceived unmet medical needs in human immunodeficiency virus-infected adults in Seoul, Korea.
Science.gov (United States)
Kang, Cho Ryok; Bang, Ji Hwan; Cho, Sung-Il; Kim, Kui Nam; Lee, Hee-Jin; Lee, Young Hwa; Ryu, Bo Yeong; Cho, Soo Kyung; Oh, Myoung-Don; Lee, Jong-Koo
2016-09-01
To identify the factors associated with perceived unmet medical needs in human immunodeficiency virus (HIV)-infected adults, we analyzed the results from a series of city-wide cross-sectional surveys of HIV-infected adults living in Seoul, Korea. Multivariate logistic regression analysis was used to identify factors related to unmet medical needs. Among the 775 subjects included in the study, 15.4% had perceived unmet medical needs. Significant factors included age group (35-49 years; adjusted odds ratio [aOR], 1.80; 95% confidence interval [CI], 1.06-3.06), lower monthly income (aOR, 3.75 for the <$900/mo group and 2.44 for the$900-\$1800/mo group; 95% CI, 1.68-8.35 and 1.18-5.04, respectively), beneficiaries of the National Medical Aid Program (aOR, 1.78; 95% CI, 1.01-3.17), recent CD4 cell counts <500/µL (aOR, 1.53; 95% CI, 1.01-2.33). Taken together, these data reveal strong associations of middle age and low socioeconomic status with perceived unmet medical needs among HIV-infected adults. PMID:27009447
13. Effect of Different Selenium Supplementation Levels on Oxidative Stress, Cytokines, and Immunotoxicity in Chicken Thymus.
Science.gov (United States)
Wang, Yachao; Jiang, Li; Li, Yuanfeng; Luo, Xuegang; He, Jian
2016-08-01
This study assessed the effects of different selenium (Se) supplementation levels on oxidative stress, cytokines, and immunotoxicity in chicken thymus. A total of 180 laying hens (1 day old; Mianyang, China) were randomly divided into 4 groups (n = 45). The chickens were maintained either on a basic diet (control group) containing 0.2 mg/kg Se, a low-supplemented diet containing 5 mg/kg Se, a medium-supplemented diet containing 10 mg/kg Se, or a high-supplemented diet containing 15 mg/kg Se for 15, 30, and 45 days, respectively. Over the entire experimental period, serum and thymus samples were collected and used for the detection of the experimental index. The results indicated that the antioxidative enzyme activities and messenger RNA (mRNA) levels of antioxidative enzymes, IFN-γ and IL-2 in the thymus, and the content of IFN-γ and IL-2 in the serum of excessive-Se-treated chickens at all time points (except for the 5 mg/kg Se supplement group at 15 days) were significantly decreased (P < 0.05) compared to the corresponding control groups. Interestingly, a significantly increase (P < 0.05) in the content of IFN-γ was observed in the serum and thymus in the 5 mg/kg Se supplement group at 15 and 30 days compared to the corresponding control groups. In histopathological examination, the thymus tissue from excessive-Se-treated chickens revealed different degrees of cortex drop, incrassation of the medulla, and degeneration of the reticular cells. These results suggested that the excessive Se could result in a decrease in immunity, an increase in oxidative damage, and a series of clinical pathology changes, such as cortex drop, incrassation of the medulla, and degeneration of the reticular cells. PMID:26740218
14. Collection of Macaca fascicularis cDNAs derived from bone marrow, kidney, liver, pancreas, spleen, and thymus
Directory of Open Access Journals (Sweden)
Kameoka Yosuke
2009-09-01
Full Text Available Abstract Background Consolidating transcriptome data of non-human primates is essential to annotate primate genome sequences, and will facilitate research using non-human primates in the genomic era. Macaca fascicularis is a macaque monkey that is commonly used for biomedical and ecological research. Findings We constructed cDNA libraries of Macaca fascicularis, derived from tissues obtained from bone marrow, liver, pancreas, spleen, and thymus of a young male, and kidney of a young female. In total, 5'-end sequences of 56,856 clones were determined. Including the previously established cDNA libraries from brain and testis, we have isolated 112,587 cDNAs of Macaca fascicularis, which correspond to 56% of the curated human reference genes. Conclusion These sequences were deposited in the public sequence database as well as in-house macaque genome database http://genebank.nibio.go.jp/qfbase/. These data will become valuable resources for identifying functional parts of the genome of macaque monkeys in future studies.
15. Relationships of CD163 and CD169 positive cell numbers in the endometrium and fetal placenta with type 2 PRRSV RNA concentration in fetal thymus.
Science.gov (United States)
Novakovic, Predrag; Harding, John C S; Ladinig, Andrea; Al-Dissi, Ahmad N; MacPhee, Daniel J; Detmer, Susan E
2016-01-01
Several routes of porcine reproductive and respiratory virus PRRSV transmission across the porcine diffuse epitheliochorial placentation have been proposed, but none have been proven. The objectives of this study were to investigate associations between numbers of CD163 and CD169 positive macrophages, cathepsin positive areolae, and type 2 PRRSV load at the maternal-fetal interface in order to examine important factors related to transplacental infection. On gestation day 85 ± 1, naïve pregnant gilts were inoculated with PRRSV (n = 114) or were sham inoculated (n = 19). At 21 days post-inoculation (dpi), dams and their litters were humanely euthanized and necropsied. Samples of the maternal-fetal interface (uterus with fully attached placenta) and fetal thymus were collected for analysis by RT-qPCR to quantify PRRSV RNA concentration. The corresponding paraffin-embedded uterine tissue sections were subjected to immunohistochemistry for PRRSV nucleocapsid N protein, CD163, CD169, and cathepsin. Our findings confirm significant increases in the numbers of PRRSV, CD163 and CD169 positive cells at the maternal-fetal interface during type 2 PRRSV infection in pregnant gilts. PRRSV load in fetal thymus was positively related to CD163(+) cell count in endometrium and negatively related to CD163(+) cell count in placenta, but unrelated to CD169 counts or cathepsin positive areolae. The endometrium:placenta ratio of CD163 cells, and to a lesser extent CD169 cells, was significantly associated with an increase fetal viral load in thymus. These findings suggest a more important role for CD163(+) cells following trans-placental PRRSV infection, but dichotomous responses in endometrium and placenta for both CD163 and CD169 cells. PMID:27494990
16. Characterizing active and inactive brown adipose tissue in adult humans using PET-CT and MR imaging.
Science.gov (United States)
Gifford, Aliya; Towse, Theodore F; Walker, Ronald C; Avison, Malcolm J; Welch, E Brian
2016-07-01
Activated brown adipose tissue (BAT) plays an important role in thermogenesis and whole body metabolism in mammals. Positron emission tomography (PET)-computed tomography (CT) imaging has identified depots of BAT in adult humans, igniting scientific interest. The purpose of this study is to characterize both active and inactive supraclavicular BAT in adults and compare the values to those of subcutaneous white adipose tissue (WAT). We obtained [(18)F]fluorodeoxyglucose ([(18)F]FDG) PET-CT and magnetic resonance imaging (MRI) scans of 25 healthy adults. Unlike [(18)F]FDG PET, which can detect only active BAT, MRI is capable of detecting both active and inactive BAT. The MRI-derived fat signal fraction (FSF) of active BAT was significantly lower than that of inactive BAT (means ± SD; 60.2 ± 7.6 vs. 62.4 ± 6.8%, respectively). This change in tissue morphology was also reflected as a significant increase in Hounsfield units (HU; -69.4 ± 11.5 vs. -74.5 ± 9.7 HU, respectively). Additionally, the CT HU, MRI FSF, and MRI R2* values are significantly different between BAT and WAT, regardless of the activation status of BAT. To the best of our knowledge, this is the first study to quantify PET-CT and MRI FSF measurements and utilize a semiautomated algorithm to identify inactive and active BAT in the same adult subjects. Our findings support the use of these metrics to characterize and distinguish between BAT and WAT and lay the foundation for future MRI analysis with the hope that some day MRI-based delineation of BAT can stand on its own. PMID:27166284
17. MAX06 and FAX06: update of two adult human phantoms for radiation protection dosimetry
International Nuclear Information System (INIS)
The International Commission on Radiological Protection (ICRP) is currently preparing new recommendations which will replace those released in ICRP 1991, 1990 Recommendations of the ICRP ICRP Publication 60 (Oxford: Pergamon). The draft report previews a change for the effective dose with respect to the number of organs and tissues to be included in its calculation. In the future, adipose tissue, connective tissue, the extrathoracic airways, the gall bladder, the heart wall, the lymphatic nodes, the prostate and the salivary glands have to be taken into account for the determination of the effective dose. This study reports on a second segmentation of the recently introduced male adult voxel (MAX) and female adult voxel (FAX) phantoms with regard to the new organs and tissues, but also presents a revised representation of the skeletons, which had not been adjusted to ICRP-based volumes in the first release of the two phantoms
18. Adult human neural stem cell therapeutics: Current developmental status and prospect
OpenAIRE
Nam, Hyun; Lee, Kee-Hang; Nam, Do-Hyun; Joo, Kyeung Min
2015-01-01
Over the past two decades, regenerative therapies using stem cell technologies have been developed for various neurological diseases. Although stem cell therapy is an attractive option to reverse neural tissue damage and to recover neurological deficits, it is still under development so as not to show significant treatment effects in clinical settings. In this review, we discuss the scientific and clinical basics of adult neural stem cells (aNSCs), and their current developmental status as ce...
19. Impact of robot responsiveness and adult involvement on children's social behaviours in human-robot interaction
OpenAIRE
Cameron, David; Fernando, Samuel; Collins, Emily; Millings, Abigail; Moore, Roger; Sharkey, Amanda; Prescott, Tony
2016-01-01
A key challenge in developing engaging social robots is creating convincing, autonomous and responsive agents, which users perceive, and treat, as social beings. As a part of the collaborative project: Expressive Agents for Symbiotic Education and Learning (EASEL), this study examines the impact of autonomous response to children's speech, by the humanoid robot Zeno, on their interactions with it as a social entity. Results indicate that robot autonomy and adult assistance during HRI can subs...
20. A comparative immunohistochemical study of aplastic thymuses for lymphocytic, epithelial, proliferative and apoptotic indices
Directory of Open Access Journals (Sweden)
Mahjoub F.
2008-03-01
Full Text Available Background: Immune deficiency is one of the major causes of morbidity and mortality in the modern world. Primary immunodeficiency comprises a wide range of disorders that mainly manifest in early childhood as devastating infections with opportunistic organisms. Thymic aplasia is found on autopsy of some patients afflicted with immune deficiency disorders, such as DiGeorge syndrome and severe combined immunodeficiency (SCID. After a thorough search of the literature, we found little information on the cellular characteristics of these thymuses. Our study aims to elucidate role of apoptosis in the pathogenesis of thymic aplasia and compare various lymphocytic and epithelial markers in normal and aplastic thymuses. Methods: We selected 12 subjects who died of severe infections with aplastic thymus found on autopsy, and 11 control subjects who died of unrelated causes, such as congenital heart disease. The presence of several markers, including Bcl2, P53, lymphocytic markers, and CD68, was examined using immunohistochemical methods on paraffin-embedded thymus sections. Positively-stained cells were counted per 1000 cells and the results stated as percentage of positive cells. Results: The mean age of the control group was between 7 days to 18 months (mean: 4.5 months. Parental consanguinity was present in 45.5% and 9.1% of the control and case groups, respectively; however, this was not statistically significant. We found significantly lower expression of Bcl2 in the case group (p value: 0.038. Furthermore, expression of CD68 was significantly higher in the case group. Epithelial markers were significantly higher in case subjects, although CD8 expression was higher in the control group. The presence of other markers was not significantly different between the two groups.Conclusions: Increase in apoptosis has a role in aplastic thymuses and prevention of apoptosis may halt this process. Also high CD68
1. Proteolytic processing of anti-Müllerian hormone differs between human fetal testes and adult ovaries
DEFF Research Database (Denmark)
Mamsen, Linn; Petersen, TS; Jeppesen, JV;
2015-01-01
From early embryonic life, anti-Müllerian hormone (AMH) is produced by Sertoli cells and is essential for male sex differentiation. In females, AMH is produced by immature granulosa cells (GCs) but a definitive function in females is uncertain. We have assessed the cellular localization...... and specificity of a panel of five novel high-affinity AMH monoclonal antibodies. Two recognize the mature C-terminal form of AMH, whereas three recognize the active pro-mature form of AMH in human tissue. The antibodies were tested on fetal male testicular and mesonephric tissue aged 8-19 weeks post conception...... (pc), fetal male serum aged 16-26 weeks pc and human immature GCs by immunofluorescence, immunohistochemistry, ELISA and western blotting. The active pro-mature forms of AMH were expressed in both Sertoli cells from human fetal testis and human immature GCs. In contrast, the mature C-terminal form...
2. Induction of Stem Cell Gene Expression in Adult Human Fibroblasts without Transgenes
OpenAIRE
Page, Raymond L.; Ambady, Sakthikumar; Holmes, William F.; Vilner, Lucy; Kole, Denis; Kashpur, Olga; Huntress, Victoria; Vojtic, Ina; Whitton, Holly; Dominko, Tanja
2009-01-01
Reprogramming of differentiated somatic cells into induced pluripotent stem (iPS) cells has potential for derivation of patient-specific cells for therapy as well as for development of models with which to study disease progression. Derivation of iPS cells from human somatic cells has been achieved by viral transduction of human fibroblasts with early developmental genes. Because forced expression of these genes by viral transduction results in transgene integration with unknown and unpredict...
3. Normative data for subcortical regional volumes over the lifetime of the adult human brain.
Science.gov (United States)
Potvin, Olivier; Mouiha, Abderazzak; Dieumegarde, Louis; Duchesne, Simon
2016-08-15
Normative data for volumetric estimates of brain structures are necessary to adequately assess brain volume alterations in individuals with suspected neurological or psychiatric conditions. Although many studies have described age and sex effects in healthy individuals for brain morphometry assessed via magnetic resonance imaging, proper normative values allowing to quantify potential brain abnormalities are needed. We developed norms for volumetric estimates of subcortical brain regions based on cross-sectional magnetic resonance scans from 2790 healthy individuals aged 18 to 94years using 23 samples provided by 21 independent research groups. The segmentation was conducted using FreeSurfer, a widely used and freely available automated segmentation software. Models predicting subcortical regional volumes of each hemisphere were produced including age, sex, estimated total intracranial volume (eTIV), scanner manufacturer, magnetic field strength, and interactions as predictors. The mean explained variance by the models was 48%. For most regions, age, sex and eTIV predicted most of the explained variance while manufacturer, magnetic field strength and interactions predicted a limited amount. Estimates of the expected volumes of an individual based on its characteristics and the scanner characteristics can be obtained using derived formulas. For a new individual, significance test for volume abnormality, effect size and estimated percentage of the normative population with a smaller volume can be obtained. Normative values were validated in independent samples of healthy adults and in adults with Alzheimer's disease and schizophrenia. PMID:27165761
4. Expression of the neurotrophin receptors Trk A and Trk B in adult human astrocytoma and glioblastoma
Shashi Wadhwa; Tapas C Nag; Anupam Jindal; Rahul Kushwaha; Ashok K Mahapatra; Chitra Sarkar
2003-03-01
Neurotrophins and their receptors of the Trk family play a critical role in proliferation, differentiation and survival of the developing neurons. There are reports on their expression in neoplasms too, namely, the primitive neuroectodermal tumours of childhood, and in adult astrocytic gliomas. The involvement of Trk receptors in tumour pathogenesis, if any, is not known. With this end in view, the present study has examined 10 tumour biopsy samples (identified as astrocytoma, pilocytic astrocytoma and glioblastoma) and peritumoral brain tissue of adult patients, for the presence of Trk A and Trk B receptors, by immunohistochemistry. The nature of the tumour samples was also confirmed by their immunoreactivity (IR) to glial fibrillary acidic protein. In the peritumoral brain tissue, only neurons showed IR for Trk A and Trk B. On the contrary, in the tumour sections, the IR to both receptors was localized in the vast majority of glia and capillary endothelium. There was an obvious pattern of IR in these gliomas: high levels of IR were present in the low-grade (type I and II) astrocytoma; whereas in the advanced malignant forms (WHO grade IV giant cell glioblastoma and glioblastoma multiforme) the IR was very weak. These findings suggest that Trk A and Trk B are involved in tumour pathogenesis, especially in the early stage, and may respond to signals that elicit glial proliferation, and thus contribute to progression towards malignancy.
5. 产前超声检测胎儿胸腺%Prenatal ultrasonic detecting and evaluating for fetal thymus
Institute of Scientific and Technical Information of China (English)
凌乐文
2012-01-01
Detecting and evaluating for fetal thymus with prenatal ultrasound is very important for diagnosis of dysplastic thymus and relative malformations or diseases. The development and application of new technology helps to the assessment of development of the fetal thymus. Ultrasonic technologies of detecting and evaluating for fetal thymus were reviewed in the article.%产前超声检测胎儿胸腺对诊断胎儿胸腺发育异常及相关畸形或疾病有重要作用,新技术的发展和应用可更全面地评估胎儿胸腺的发育.本文对胎儿胸腺超声检测技术及临床应用进行综述.
6. Invasion by Neisseria meningitidis varies widely between clones and among nasopharyngeal mucosae derived from adult human hosts.
Science.gov (United States)
Townsend, Robert; Goodwin, Linda; Stevanin, Tania M; Silcocks, Paul B; Parker, Andrew; Maiden, Martin C J; Read, Robert C
2002-05-01
Colonization of the human nasopharynx is a feature of some species of Neisseria, and is a prerequisite of invasive meningococcal disease. The likelihood of colonization by Neisseria meningitidis varies widely between humans, and very few develop invasive disease. Explants of nasal mucosa derived from adult patients with non-allergic nasal obstruction were infected experimentally with Neisseria spp. At intervals over 18 h incubation, washed explants were homogenized, and viable bacteria were counted. To estimate bacterial invasion of mucosa, explants were exposed to 0.25% sodium taurocholate for 30 s prior to homogenization. N. meningitidis was recovered from the mucosa and the organism invaded and replicated within the tissue, in contrast to N. lactamica and N. animalis (n=9, Pcoefficient of variation of recovered viable counts was 1335% after 4 h and 77% after 18 h incubation. It is concluded that the distinctive colonization and disease potential of Neisseria spp. may be partly a consequence of their ability to invade and survive within human nasopharyngeal mucosa, but that this is influenced greatly by genetic or environmental factors operating on the host mucosa. This is consistent with the unpredictable epidemiology of meningococcal disease. PMID:11988521
7. The presence and absence of lymphatic vessels in the adult human intervertebral disc: relation to disc pathology
International Nuclear Information System (INIS)
Although the normal adult human intervertebral disc is considered to be avascular, vascularised cellular fibrous tissue can be found in pathological conditions involving the disc such as disc herniation. Whether lymphatics vessels form a component of this reparative tissue is not known as the presence or absence of lymphatics in herniated and normal disc tissue is not known. We examined spinal tissues and discectomy specimens for the presence of lymphatics. The examination used immunohistochemistry to identify the specific lymphatic endothelial cell markers, podoplanin and LYVE1. Lymphatic vessels were not found in the nucleus pulposus or annulus fibrosus of intact, non-herniated lumbar and thoracic discs but were present in the surrounding ligaments. Ingrowth of fibrous tissue was seen in 73% of herniated disc specimens of which 36% contained LYVE1+/podoplanin + lymphatic vessels. Lymphatic vessels were not seen in the sacrum and coccyx or biopsies of four sacrococcygeal chordomas, but they were noted in surrounding extra-osseous fat and fibrous tissue at the edge of the infiltrating tumour. Our findings indicate that lymphatic vessels are not present in the normal adult intervertebral disc but that, when there is extrusion of disc material into surrounding soft tissue, there is ingrowth of reparative fibrous tissue containing lymphatic vessels. Our findings also indicate that chordoma, a tumour of notochordal origin, spreads to regional lymph nodes via lymphatics in para-spinal soft tissues. (orig.)
8. Validation of case-finding algorithms derived from administrative data for identifying adults living with human immunodeficiency virus infection.
Directory of Open Access Journals (Sweden)
Tony Antoniou
Full Text Available OBJECTIVE: We sought to validate a case-finding algorithm for human immunodeficiency virus (HIV infection using administrative health databases in Ontario, Canada. METHODS: We constructed 48 case-finding algorithms using combinations of physician billing claims, hospital and emergency room separations and prescription drug claims. We determined the test characteristics of each algorithm over various time frames for identifying HIV infection, using data abstracted from the charts of 2,040 randomly selected patients receiving care at two medical practices in Toronto, Ontario as the reference standard. RESULTS: With the exception of algorithms using only a single physician claim, the specificity of all algorithms exceeded 99%. An algorithm consisting of three physician claims over a three year period had a sensitivity and specificity of 96.2% (95% CI 95.2%-97.9% and 99.6% (95% CI 99.1%-99.8%, respectively. Application of the algorithm to the province of Ontario identified 12,179 HIV-infected patients in care for the period spanning April 1, 2007 to March 31, 2009. CONCLUSIONS: Case-finding algorithms generated from administrative data can accurately identify adults living with HIV. A relatively simple "3 claims in 3 years" definition can be used for assembling a population-based cohort and facilitating future research examining trends in health service use and outcomes among HIV-infected adults in Ontario.
9. Suicidal ideation and suicide attempts among human immunodeficiency virus-infected adults: differences in risk factors and their implications.
Science.gov (United States)
Kang, Cho Ryok; Bang, Ji Hwan; Cho, Sung-Il; Kim, Kui Nam; Lee, Hee-Jin; Ryu, Bo Yeong; Cho, Soo Kyung; Lee, Young Hwa; Oh, Myoung-Don; Lee, Jong-Koo
2016-01-01
Many studies have investigated risk factors for suicidal ideation and suicide attempt; however, most have failed to show differences in risk factors between suicidal ideation and suicide attempt among the human immunodeficiency virus (HIV)-infected population. This study was designed to identify differences in risk factors between suicidal ideation and suicide attempts among HIV-infected adults in Seoul. A face-to-face survey of 457 HIV-infected adults was conducted by the Seoul Metropolitan Government in 2013. Multivariate logistic regression analysis was used to identify factors associated with suicidal ideation and suicide attempt. Among 422 participants, 44% had suicidal ideation, and 11% had suicide attempts. The independent risk factors for suicidal ideation were young and middle age, living with someone, history of AIDS-defining opportunistic disease, history of treatment for depression, lower social support, and psychological status. Beneficiaries of National Medical Aid, economic barriers to treatment, history of treatment for depression, and lower psychological status were independently associated with suicide attempts. Patients with HIV in Korea were treated without cost in some centers. Thus, experiencing an economic barrier to treatment might be due in part to ignorance of HIV care policies. Our findings indicate that suicide attempts are associated with socioeconomic factors and information inequality regarding medical care. In conclusion, suicidal ideation closely associated with the psychosocial factors, whereas suicide attempt demonstrates a stronger association with socioeconomic factors. Suicide prevention measures should be implemented to provide information to help HIV-infected patients. PMID:26444525
10. The presence and absence of lymphatic vessels in the adult human intervertebral disc: relation to disc pathology
Energy Technology Data Exchange (ETDEWEB)
Kliskey, Karolina; Williams, Kelly; Yu, J.; Urban, Jill; Athanasou, Nick [University of Oxford, Nuffield Department of Orthopaedic, Rheumatology and Musculoskeletal Science, Oxford (United Kingdom); Jackson, David [Weatherall Institute of Molecular Medicine, Human Immunology Unit, Oxford (United Kingdom)
2009-12-15
Although the normal adult human intervertebral disc is considered to be avascular, vascularised cellular fibrous tissue can be found in pathological conditions involving the disc such as disc herniation. Whether lymphatics vessels form a component of this reparative tissue is not known as the presence or absence of lymphatics in herniated and normal disc tissue is not known. We examined spinal tissues and discectomy specimens for the presence of lymphatics. The examination used immunohistochemistry to identify the specific lymphatic endothelial cell markers, podoplanin and LYVE1. Lymphatic vessels were not found in the nucleus pulposus or annulus fibrosus of intact, non-herniated lumbar and thoracic discs but were present in the surrounding ligaments. Ingrowth of fibrous tissue was seen in 73% of herniated disc specimens of which 36% contained LYVE1+/podoplanin + lymphatic vessels. Lymphatic vessels were not seen in the sacrum and coccyx or biopsies of four sacrococcygeal chordomas, but they were noted in surrounding extra-osseous fat and fibrous tissue at the edge of the infiltrating tumour. Our findings indicate that lymphatic vessels are not present in the normal adult intervertebral disc but that, when there is extrusion of disc material into surrounding soft tissue, there is ingrowth of reparative fibrous tissue containing lymphatic vessels. Our findings also indicate that chordoma, a tumour of notochordal origin, spreads to regional lymph nodes via lymphatics in para-spinal soft tissues. (orig.)
11. Study of calf thymus DNA irradiated in vitro with MeV fluorine ions
International Nuclear Information System (INIS)
A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis, modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC). The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel electrophoresis, there was no observable product in the range of 1,000-30,000 (m/q) using MALDI-TOF, and small biomolecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom. (authors)
12. ACTH-producing neuroendocrine tumor of thymus with recurrences. Clinical case
Directory of Open Access Journals (Sweden)
E A Dobreva
2015-06-01
Full Text Available One of the most difficult in diagnostic and treatment options for endogenous Cushing is the ectopic ACTH syndrome, which causes the development of tumors of different histogenesis localization producing adrenocorticotropic hormone (ACTH, and much less - corticotropin hormone (CRH. ACTH-secreting tumors varied in location, morphological structure and the degree of malignancy. Most of these tumors are characterized by an aggressive course with a propensity to metastasize and relapse. The article presents data of the prevalence, pathogenesis of ectopic ACTH tumors localized in the thymus, analyzis of clinical, morphological features, the methods of diagnosis and treatment. Based on the current literature, the world and our own experience on the diagnosis and treatment of patients with ectopic ACTH syndrome with localization of hormone production in the thymus, we want to highlight the current state of the problem in order to create the most efficient algorithm for diagnostic search and treatment of this difficult group of patients.
13. Study of calf thymus DNA irradiated in vitro with MeV fluorine ions
Institute of Scientific and Technical Information of China (English)
2006-01-01
A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis,modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC).The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel electrophoresis, there was no observable product in the range of 1,000- 30,000 (m/q) using MALDI-TOF, and small biomolecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom.
14. Myasthenia gravis: 75Se-seleno-methionine scanning of thymus gland
International Nuclear Information System (INIS)
The 75Se-seleno-methionine isotope thymus scanning was examined in a series of patients with myasthenia gravis. The patients were given 4 μC/kg hence a total of 250-300 μC 75Se-seleno-methionine, intravenously. The method proved useful and informative in the diagnostics of myasthenia. Prior to thymectomy, the thymic tumour or a large gland could be observed and some hints could be gained for the biological activity of the gland. After the operation, the success of thymectomy could be checked and later a possible recidive could be shown or excluded. In non-operative cases the change in thymic activity could be followed which was an important sign of a malignant or tumorous growth of the thymus. (author)
15. Antifungal Activity of Extracts of Rosmarinus officinalis and Thymus vulgaris against Aspergillus flavus and A. ochraceus
Directory of Open Access Journals (Sweden)
2010-01-01
Full Text Available The antifungal activity of ethanolic extracts of Rosmarinus officinalis and Thymus vulgaris were tested against strains of Aspergillus flavus and A. ochraceus, since these two species are common contaminants of cereals and grains and are able to produce and accumulate mycotoxins. The methodology used is based on measuring the inhibition halos produced by discs impregnated with the extracts and establishing their Minimum Inhibitory Concentration (MIC as well as the Minimum Fungicide Concentration (MFC. The results obtained suggest that the assayed extracts affect the proper development of A. flavus and A. ochraceus; leading to a lower MIC (1200 ppm and MFC (2400 ppm for T. vulgaris extract against A. ochraceus than against A. flavus. The results show, that the extracts of Rosmarinus officinalis and Thymus vulgaris used at low concentrations could have significant potential for the biological control of fungi in foodstuffs.
16. Expression, crystallization and structure elucidation of γ-terpinene synthase from Thymus vulgaris.
Science.gov (United States)
Rudolph, Kristin; Parthier, Christoph; Egerer-Sieber, Claudia; Geiger, Daniel; Muller, Yves A; Kreis, Wolfgang; Müller-Uri, Frieder
2016-01-01
The biosynthesis of γ-terpinene, a precursor of the phenolic isomers thymol and carvacrol found in the essential oil from Thymus sp., is attributed to the activitiy of γ-terpinene synthase (TPS). Purified γ-terpinene synthase from T. vulgaris (TvTPS), the Thymus species that is the most widely spread and of the greatest economical importance, is able to catalyze the enzymatic conversion of geranyl diphosphate (GPP) to γ-terpinene. The crystal structure of recombinantly expressed and purified TvTPS is reported at 1.65 Å resolution, confirming the dimeric structure of the enzyme. The putative active site of TvTPS is deduced from its pronounced structural similarity to enzymes from other species of the Lamiaceae family involved in terpenoid biosynthesis: to (+)-bornyl diphosphate synthase and 1,8-cineole synthase from Salvia sp. and to (4S)-limonene synthase from Mentha spicata. PMID:26750479
17. Antioxidant and Antiproliferative Activities of the Essential Oils from Thymbra capitata and Thymus Species Grown in Portugal
OpenAIRE
Maria Graça Miguel; Custódia Gago; Maria Dulce Antunes; Cristina Megías; Isabel Cortés-Giraldo; Javier Vioque; A. Sofia Lima; A. Cristina Figueiredo
2015-01-01
Copyright © 2015 Maria Graça Miguel et al. The antioxidant and antiproliferative activities of the essential oils from Thymbra capitata and Thymus species grown in Portugal were evaluated. Thymbra and Thymus essential oils were grouped into two clusters: Cluster I in which carvacrol, thymol, p-cymene, α-terpineol, and γ-terpinene dominated and Cluster II in which thymol and carvacrol were absent and the main constituent was linalool. The ability for scavenging ABTS·+ and peroxyl free radicals...
18. Effect of protein malnutrition on the glycolytic and glutaminolytic enzyme activity of rat thymus and mesenteric lymph nodes
OpenAIRE
M.A. dos-Santos; Rosa, R; Curi, R.; D.H.G.P Barbieri
1997-01-01
The activity of important glycolytic enzymes (hexokinase, phosphofructokinase, aldolase, phosphohexoseisomerase, pyruvate kinase and lactate dehydrogenase) and glutaminolytic enzymes (phosphate-dependent glutaminase) was determined in the thymus and mesenteric lymph nodes of Wistar rats submitted to protein malnutrition (6% protein in the diet rather than 20%) from conception to 12 weeks after birth. The wet weight (g) of the thymus and mesenteric lymph nodes decreased due to protein malnutri...
19. Theoretical study of interactions between human adult hemoglobin and acetate ion by polarizable force field and fragmentation quantum chemistry methods
Institute of Scientific and Technical Information of China (English)
YAN XiuFen; JIANG Nan; MA Jing
2009-01-01
A series of theoretical approaches,including conventional FF03 and FF03-based polarization model,as well as the generalized energy-based fragmentation (GEBF) quantum chemistry method,have been applied to investigate the interactions between acetate ion (CH_3COO~-) and the α-subunit of human adult hemoglobin (designated as Hb-α) at four binding sites (Lys16,Lys90,Arg92,and Lys127),respectively.The FF03-based polarizable force fields show that the interaction energies between the CH_3COO~-group and Hb-α follow the trend of Arg92＞Lys127＞Lys90＞Lys16.The complexation of CH_3COO~-with Hb-α is governed by the long-range electrostatic interactions and steric effect.
20. Human fetal cardiac progenitors: The role of stem cells and progenitors in the fetal and adult heart.
Science.gov (United States)
Bulatovic, Ivana; Månsson-Broberg, Agneta; Sylvén, Christer; Grinnemo, Karl-Henrik
2016-02-01
The human fetal heart is formed early during embryogenesis as a result of cell migrations, differentiation, and formative blood flow. It begins to beat around gestation day 22. Progenitor cells are derived from mesoderm (endocardium and myocardium), proepicardium (epicardium and coronary vessels), and neural crest (heart valves, outflow tract septation, and parasympathetic innervation). A variety of molecular disturbances in the factors regulating the specification and differentiation of these cells can cause congenital heart disease. This review explores the contribution of different cardiac progenitors to the embryonic heart development; the pathways and transcription factors guiding their expansion, migration, and functional differentiation; and the endogenous regenerative capacity of the adult heart including the plasticity of cardiomyocytes. Unfolding these mechanisms will become the basis for understanding the dynamics of specific congenital heart disease as well as a means to develop therapy for fetal as well as postnatal cardiac defects and heart failure. PMID:26421632
1. Role of the Subunits Interactions in the Conformational Transitions in Adult Human Hemoglobin: an Explicit Solvent Molecular Dynamics Study
CERN Document Server
Yusuff, Olaniyi K; Bussi, Giovanni; Raugei, Simone
2012-01-01
Hemoglobin exhibits allosteric structural changes upon ligand binding due to the dynamic interactions between the ligand binding sites, the amino acids residues and some other solutes present under physiological conditions. In the present study, the dynamical and quaternary structural changes occurring in two unligated (deoxy-) T structures, and two fully ligated (oxy-) R, R2 structures of adult human hemoglobin were investigated with molecular dynamics. It is shown that, in the sub-microsecond time scale, there is no marked difference in the global dynamics of the amino acids residues in both the oxy- and the deoxy- forms of the individual structures. In addition, the R, R2 are relatively stable and do not present quaternary conformational changes within the time scale of our simulations while the T structure is dynamically more flexible and exhibited the T\\rightarrow R quaternary conformational transition, which is propagated by the relative rotation of the residues at the {\\alpha}1{\\beta}2 and {\\alpha}2{\\b...
2. Effects of magnesium alloys extracts on adult human bone marrow-derived stromal cell viability and osteogenic differentiation
Energy Technology Data Exchange (ETDEWEB)
Yang Chunxi; Dai Kerong [Department of Orthopedics, Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011 (China); Yuan Guangyin; Zhang Jia [National Engineering Research Center of Light Alloys Net Forming (LAF), School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Tang Ze; Zhang Xiaoling [Lab of Osteopaedic Cellular and Molecular Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS) and Shanghai Jiao Tong University School of Medicine - SJTUSM, Shanghai 200025 (China)
2010-08-01
In this study, adult human bone marrow-derived stromal cells (hBMSCs) were cultured in extracts of magnesium (Mg) and the Mg alloys AZ91D and NZ30K for 12 days. We studied the indirect effects of Mg alloys on hBMSC viability. Alkaline phosphatase activity and the expression of osteogenic differentiation marker genes were used to evaluate the effects of the Mg alloys on the osteogenic differentiation of hBMSCs. The results indicate that {<=}10 mM concentration of Mg in the extracts did not inhibit the viability and osteogenic differentiation of hBMSCs. However, the results suggest that the high pH of the extracts, which is a result of the rapid corrosion of Mg and the Mg alloys, is unfavorable to the viability and osteogenic differentiation of hBMSCs.
3. Effects of magnesium alloys extracts on adult human bone marrow-derived stromal cell viability and osteogenic differentiation
International Nuclear Information System (INIS)
In this study, adult human bone marrow-derived stromal cells (hBMSCs) were cultured in extracts of magnesium (Mg) and the Mg alloys AZ91D and NZ30K for 12 days. We studied the indirect effects of Mg alloys on hBMSC viability. Alkaline phosphatase activity and the expression of osteogenic differentiation marker genes were used to evaluate the effects of the Mg alloys on the osteogenic differentiation of hBMSCs. The results indicate that ≤10 mM concentration of Mg in the extracts did not inhibit the viability and osteogenic differentiation of hBMSCs. However, the results suggest that the high pH of the extracts, which is a result of the rapid corrosion of Mg and the Mg alloys, is unfavorable to the viability and osteogenic differentiation of hBMSCs.
4. Contribution of non-genetic factors to dopamine and serotonin receptor availability in the adult human brain
DEFF Research Database (Denmark)
Borg, J; Cervenka, S; Kuja-Halkola, R; Matheson, G J; Jönsson, E G; Lichtenstein, P; Henningsson, S; Ichimiya, T; Larsson, H; Stenkrona, P; Halldin, C; Farde, L
2016-01-01
and environmental factors, respectively, on dopaminergic and serotonergic markers in the living human brain. Eleven monozygotic and 10 dizygotic healthy male twin pairs were examined with PET and [(11)C]raclopride binding to the D2- and D3-dopamine receptor and [(11)C]WAY100635 binding to the......The dopamine (DA) and serotonin (5-HT) neurotransmission systems are of fundamental importance for normal brain function and serve as targets for treatment of major neuropsychiatric disorders. Despite central interest for these neurotransmission systems in psychiatry research, little is known about...... binding and a major contribution of environmental factors (pairwise shared and unique individual; 0.70-0.75) on neocortical 5-HT1A receptor binding. Our findings indicate that individual variation in neuroreceptor availability in the adult brain is the end point of a nature-nurture interplay, and call for...
5. Epidemiology of human hookworm infections among adult villagers in Hejiang and Santai Counties, Sichuan Province, China.
Science.gov (United States)
Changhua, L; Xiaorong, Z; Dongchuan, Q; Shuhua, X; Hotez, P J; Defu, Z; Hulian, Z; Mingden, L; Hainan, R; Bing, Z; Haichou, X; Hawdon, J; Zheng, F
1999-10-15
Hookworm infection as well as other intestinal nematodiases are endemic to Sichuan Province in China. In order to research the prevalence and intensity of these infections we visited two villages in Hejiang County (southern Sichuan Province) and Santai County (northwestern Sichuan Province) between July and October of 1997. Fecal examinations were performed on adult villagers over the age of 15 years (currently children under this age are dewormed annually with anthelmintic drugs). Among 310 residents of Lugao Village (Hejiang County), 87, 63 and 60% were infected with hookworm, Ascaris or Trichuris, respectively. The prevalence of hookworm determined to rise linearly with age (r = 0.97). High intensity infections with hookworm still occur in this region as 22% of the residents have over 3000 eggs per gram (PEG) of feces as determined by quantitative egg counts. The majority of these individuals harbored mixed infection with Necator americanus and Ancylostoma duodenale, although the former predominated when adult hookworms were collected from 30 village residents treated with pyrantel pamoate. In contrast, among the 334 Xinjian villagers examined (Santai County) the majority harbored predominantly light hookworm infections--66.1% of the residents has less than 400 EPG by quantitative fecal examination and only 3.7% exhibited greater than 3000 EPG. Again, N. americanus was the predominant hookworm seen after worm expulsion. We have round that despite economic development which is occurring in some parts of China, significant hookworm infections and clinical hookworm anemia still exist in areas of Sichuan Province. In Hejiang County we found that the intensity of hookworm infection has actually risen within the last 10 years. Hookworm is a medical problem among the elderly in Sichuan. PMID:10546842
6. Morphological and Physiological Plant Responses to Drought Stress in Thymus citriodorus
OpenAIRE
Zdzislaw Attila Tátrai; Rabab Sanoubar; Zsuzsanna Pluhár; Silvia Mancarella; Francesco Orsini; Giorgio Gianquinto
2016-01-01
Water availability is considered as a determinant factor that affects plant growth. The commercial medicinal values of an aromatic plant rely on the presence of secondary metabolites that are affected under water shortage. Two-year-old Thymus citriodorus plants were subjected to different polyethylene glycol (PEG-6000) levels (0, 2%, and 4%) under greenhouse condition. PEG treatment lasted for 15 days. Thyme plant showed a morphological drought avoidance mechanism by maintaining the root syst...
7. Molecular and biotechnological approaches to essential oils production in thymus caespititius
OpenAIRE
Mendes, Marta Daniela de Sá
2014-01-01
Tese de doutoramento, Biologia (Biotecnologia), Universidade de Lisboa, Faculdade de Ciências, 2014 Thymus caespititius is an aromatic plant from the NW Iberian Peninsula and from the Azores and Madeira archipelagos. In this species chemical polymorphism in the essential oils has been described, with seven well defined chemotypes, namely thymol, carvacrol, α-terpineol, sabinene, and the mixed chemotypes thymol/sabinene, thymol/carvacrol and thymol/sabinene/carvacrol. T. caespititius essent...
8. Chemical composition and antioxidative activity of essential oil of Thymus serpyllum L.
OpenAIRE
Petrović Slobodan S.; Ristić Mihailo S.; Babović Nada V.; Lazić Miodrag L.; Francišković Marina; Petrović Slobodan D.
2014-01-01
Wild thyme (Thymus serpyllum L.) is a popular remedy regarding both traditional and conventional medicine. It is used as the antiseptic, aromatic, expectorant, stomachic, antispasmodic, carminative and preservative substance. For the purpose of this paper, wild thyme essential oil was isolated from the dried herb T. serpyllum by hydrodistillation. Original semi-industrial distillation device SP-130 performing distillation by water and steam was used for the...
9. T cell precursor migration towards beta 2-microglobulin is involved in thymus colonization of chicken embryos
DEFF Research Database (Denmark)
Dunon, D; Kaufman, J; Salomonsen, J; Skjoedt, K; Vainio, O; Thiery, J P; Imhof, B A
1990-01-01
beta 2-microglobulin (beta 2m) attracts hemopoietic precursors from chicken bone marrow cells in vitro. The cell population responding to beta 2m increases during the second period of thymus colonization, which takes place at days 12-14 of incubation. The precursors from 13.5 day old embryos were...... which suggest that beta 2m mediated chemotaxis is involved in the second wave. Udgivelsesdato: 1990-Oct...
10. Conformation and Rheological Properties of Calf-Thymus DNA in Solution
OpenAIRE
Lourdes Mónica Bravo-Anaya; Marguerite Rinaudo; Félix Armando Soltero Martínez
2016-01-01
Studies of DNA molecule behavior in aqueous solutions performed through different approaches allow assessment of the solute-solvent interactions and examination of the strong influence of conformation on its physicochemical properties, in the presence of different ionic species and ionic concentrations. Firstly, the conformational behavior of calf-thymus DNA molecules in TE buffer solution is presented as a function of temperature. Secondly, their rheological behavior is discussed, as well as...
11. A Case of Carcinoma Showing Thymus-Like Differentiation with a Rapidly Lethal Course
OpenAIRE
Nogami,Tomohiro; Taira, Naruto; Toyooka, Shinichi; Tanaka, Takehiro; Mizoo, Taeko; Iwamoto, Takayuki; Shien, Tadahiko; Soh, Junichi; Miyoshi, Shinichiro; Doihara, Hiroyoshi
2014-01-01
A 55-year-old woman underwent a total thyroidectomy for carcinoma showing thymus-like differentiation (CASTLE). The patient was referred to our hospital after the tumor was found to have directly invaded the cervical esophagus and the entire circumference of the trachea. A total thyroidectomy was performed, followed by end-to-end anastomosis of the trachea, suprahyoid release and dissection of bilateral pulmonary ligaments. No major complications, including anastomotic dehiscence or stenosis,...
12. Influence of the thymus on hemopoietic stem cells capability to repair sublethal radiation damages
International Nuclear Information System (INIS)
In the course of irradiation of mice bone marrow (300 rad in vitro + 300 rad in vivo) hemopoietic stem cells injury decreases significantly at the irradiation interval of 5 hrs as compared to 30 min interval at the expence of repairment from sublethal radiation damages (the Elkind repair effect). In case of thymectomized mature mice, the capability of hemopoietic stem cells for the Elkind repair is sharply distorted when 2/2-5 months after operation. Thymus transplantation removes thymectomy effect
13. Irradiated fetal thymus transplantation in a patient with combined immunodeficiency with predominant T cell defect
Energy Technology Data Exchange (ETDEWEB)
Higuchi, Shigenori; Yanabe, Yasuhide; Tsuchiya, Hiroyuki; Akahoshi, Izumi; Migita, Masahiro; Matsuda, Ichiro (Kumamoto Univ. (Japan). School of Medicine); Udaka, Keiji
1993-02-01
A 6 month old boy was diagnosed as a case of combined immunodeficiency (with predominant T cell defect by previous classification). His T cell count was decreased, his B cell count in peripheral blood was increased, his serum IgG level was decreased, his serum IgM level was normal and the thymus was not evident on CT scans and magnetic resonance imaging. Administration of the thymus hormone, thymosin, led to a partial recovery of T cell function without normalization of the T cell count. At age 26 months the patient received an irradiated thymus transplantation from a 16 week old female fetus. After the transplantation, the T cell count (mainly CD4[sup +] cells) increased by 50-70%. A mild graft-versus-host reaction (GVHR) occurred and several immunosuppressants were prescribed. Chromosome analysis showed that the T cells have both 46 XY and 46 XX karyotypes while the B cells have the 46 XY karyotype alone. His cellular immunity (skin tests, DNA synthesis, mixed lymphocyte reaction, cytotoxic activity and natural killer cell function) and his serum IgG level remained low. However, being on regular [gamma]-globulin therapy and oral anti-fungal drugs, he is now living normally with almost no trouble at age 6 years and 3 months. This case showed that irradiated thymus transplantation might be a useful method when an adequate donor for bone marrow transplantation is not available. The unexpected observation that the increased T cells were mainly CD4 may be related to the mild GVHR and the clinical improvement. (author).
14. Chemical Composition and Insecticidal Properties of Thymus numidicus (Poiret) Essential Oil from Algeria
OpenAIRE
Saidj, Faiza; Rezzoug, Sid-Ahmed; Bentahar, Fatiha; Boutekedjiret, Chahrazed
2008-01-01
Essential oils of thyme (Thymus numidicus (Poiret)) from Algeria were isolated by steam distillation, analysed by gas chromatography coupled with the mass spectrometry (GC-MS) and investigated for their insecticidal activities against Rhizopertha dominica. Contact toxicity of global oil recovered after one hour of extraction and its fraction F1 recovered after 2.5 minutes of extraction were tested using the filter paper method. Analysis of the essential oil made it possible to identify 14 com...
15. Portuguese Thymbra and Thymus species volatiles: chemical composition and biological activities.
Science.gov (United States)
Figueiredo, A C; Barroso, J G; Pedro, L G; Salgueiro, L; Miguel, M G; Faleiro, M L
2008-01-01
Thymbra capitata and Thymus species are commonly known in Portugal as thyme and they are currently used as culinary herbs, as well as for ornamental, aromatizing and traditional medicinal purposes. The present work reports on the state of the art on the information available on the taxonomy, ethnobotany, cell and molecular biology of the Portuguese representatives of these genera and on the chemotaxonomy and antibacterial, antifungal and antioxidant activities of their essential oils and other volatile-containing extracts. PMID:19075695
16. Visualization of the thymus by substance P receptor scintigraphy in man
Energy Technology Data Exchange (ETDEWEB)
Hagen, P.M. van [Department of Immunology, Erasmus University, Rotterdam (Netherlands)]|[Department of Internal Medicine III, Erasmus University, Rotterdam (Netherlands); Breeman, W.A.P. [Department of Nuclear Medicine, Erasmus University, Rotterdam (Netherlands); Reubi, J.C. [Department of Pathology, University of Berne (Switzerland); Postema, P.T.E. [Department of Internal Medicine III, Erasmus University, Rotterdam (Netherlands); Anker-Lugtenburg, P.J. van den [Department of Hematology, Erasmus University, Rotterdam (Netherlands); Kwekkeboom, D.J. [Department of Nuclear Medicine, Erasmus University, Rotterdam (Netherlands); Laissue, J. [Department of Pathology, University of Berne (Switzerland); Waser, B. [Department of Pathology, University of Berne (Switzerland); Lamberts, S.W.J. [Department of Internal Medicine III, Erasmus University, Rotterdam (Netherlands); Visser, T.J. [Department of Internal Medicine III, Erasmus University, Rotterdam (Netherlands); Krenning, E.P. [Department of Internal Medicine III, Erasmus University, Rotterdam (Netherlands)]|[Department of Nuclear Medicine, Erasmus University, Rotterdam (Netherlands)
1996-11-01
In this study we present the results concerning the metabolism of the substance P analogue [{sup 111}In-DTPA-Arg{sup 1}]-substance P in man, as well as the visualization of the thymus in patients with immune-mediated diseases. Twelve selected patients were investigated, comprising five with inflammatory bowel disease, one with ophthalmic Graves disease, one with sclerosing cholangitis, one with Sjoegrens syndrome, one with rheumatoid arthritis, one with systemic lupus erythematosus and two with myasthenia gravis. After intravenous administration of 150-250 MBq (2.5-5.0 {mu}g) [{sup 111}In-DTPA-Arg{sup 1}]-substance P, radioactivity was measured in blood, urine and faeces for 48 h. Planar and single-photon emission tomographic images were obtained 4 and 24 h after injection. After administration of [{sup 111}In-DTPA-Arg{sup 1}]-substance P, a transient flush was observed in all patients. Degradation of [{sup 111}In-DTPA-Arg{sup 1}]-substance P started in the first minutes after administration, resulting in a half-life of 10 min for the total plasma radioactivity, and of 4 min for the intact radiopharmaceutical. Urinary excretion accounted for >95% of the radioactivity within 24 h post injection, and up to 0.05% was found in the faeces up to 60 h. In all patients uptake of radioactivity was found in the areolae mammae (in women), liver, spleen, kidneys and urinary bladder. In eight patients a high uptake of [{sup 111}In-DTPA-Arg{sup 1}]-substance P was observed in the thymus. We conclude that, despite its short half-life, [{sup 111}In-DTPA-Arg{sup 1}]-substance P can be used to visualize the thymus. This may contribute to the investigation of the role of thymus in immune-mediated diseases. In addition, inflammatory sites in various diseases could be visualized. (orig.). With 6 figs., 1 tab.
17. Morphology, distribution, and histochemistry of trichomes of Thymus lykae Degen & Jav. (Lamiaceae)
OpenAIRE
Marin Marija; Budimir Snežana; Janošević Dušica; Marin P.D.; Duletić-Laušević Sonja; Ljaljević-Grbić Milica
2008-01-01
Micromorphology, distribution, and histochemistry of the trichomes of Thymus lykae were studied using scanning electron microscopy (SEM)and confocal laser scanning electron microscopy (CLSM). The leaves, stem, and calyx bear numerous glandular and non-glandular trichomes. Two types of glandular trichomes are identified - peltate and capitate. Results of histochemical tests showed positive reactions to polysaccharides, proteins, and lipids. Yellow autofluorescence of secreted material was noti...
18. MHC class II antigen expression was different from MHC class I antigen expression in irradiated and recovering rat thymus
International Nuclear Information System (INIS)
We exposed rats to a heavy, but sublethal, dose of X-radiation that was calculated as the maximum that left them alive. Immediately after irradiation the rats lost body and thymus weight. The number of thymocytes decreased and the structure of the thymus was destroyed. The thymus weights then increased rapidly for a few days from day 7 followed by a slower increase. Immunohistochemically, the recovery of major histocompatibility complex (MHC) class II-positive cells in the thymus was slower than that of MHC class I-positive cells. Recovery of MHC class II-positive and ED1-positive cells in the thymus was slow, especially in the medulla. Thymus structure appeared similar to normal control animals on day 14, although the number of MHC class II- and ED1-positive cells in the medulla was lower than that of controls even 21 days after radiation exposure. The delay in recovery of MHC class II-positive stromal cells might affect the regeneration of thymocyte subpopulations after irradiation. (author)
19. Integration of Human Resource Development and Adult Education Theories and Practices: Implications for Organizational Learning
Science.gov (United States)
Akdere, Mesut; Conceicao, Simone
2006-01-01
The field of Human Resource Development has initially evolved and executed practice around a behaviorist business approach which has become inadequate and inefficient in addressing the multilevel challenges of today's complex organizations and meeting the needs of a new workforce that is increasingly becoming diverse. However, this trend is now…
20. Localization of laminin alpha4-chain in developing and adult human tissues.
Science.gov (United States)
Petäjäniemi, Noora; Korhonen, Matti; Kortesmaa, Jarkko; Tryggvason, Karl; Sekiguchi, Kiyotoshi; Fujiwara, Hironobu; Sorokin, Lydia; Thornell, Lars-Eric; Wondimu, Zenebech; Assefa, Daniel; Patarroyo, Manuel; Virtanen, Ismo
2002-08-01
Recent studies suggest important functions for laminin-8 (Ln-8; alpha4beta1gamma1) in vascular and blood cell biology, but its distribution in human tissues has remained elusive. We have raised a monoclonal antibody (MAb) FC10, and by enzyme-linked immunoassay (EIA) and Western blotting techniques we show that it recognizes the human Ln alpha4-chain. Immunoreactivity for the Ln alpha4-chain was localized in tissues of mesodermal origin, such as basement membranes (BMs) of endothelia, adipocytes, and skeletal, smooth, and cardiac muscle cells. In addition, the Ln alpha4-chain was found in regions of some epithelial BMs, including epidermis, salivary glands, pancreas, esophageal and gastric glands, intestinal crypts, and some renal medullary tubules. Developmental differences in the distribution of Ln alpha4-chain were detected in skeletal muscle, walls of vessels, and intestinal crypts. Ln alpha4- and Ln alpha2-chains co-localized in BMs of fetal skeletal muscle cells and in some epithelial BMs, e.g., in gastric glands and acini of pancreas. Cultured human pulmonary artery endothelial (HPAE) cells produced Ln alpha4-chain as M(r) 180,000 and 200,000 doublet and rapidly deposited it to the growth substratum. In cell-free extracellular matrices of human kidney and lung, Ln alpha4-chain was found as M(r) 180,000 protein. PMID:12133914
1. Low Proliferation and Differentiation Capacities of Adult Hippocampal Stem Cells Correlate with Memory Dysfunction in Humans
Science.gov (United States)
Coras, Roland; Siebzehnrubl, Florian A.; Pauli, Elisabeth; Huttner, Hagen B.; Njunting, Marleisje; Kobow, Katja; Villmann, Carmen; Hahnen, Eric; Neuhuber, Winfried; Weigel, Daniel; Buchfelder, Michael; Stefan, Hermann; Beck, Heinz; Steindler, Dennis A.; Blumcke, Ingmar
2010-01-01
The hippocampal dentate gyrus maintains its capacity to generate new neurons throughout life. In animal models, hippocampal neurogenesis is increased by cognitive tasks, and experimental ablation of neurogenesis disrupts specific modalities of learning and memory. In humans, the impact of neurogenesis on cognition remains unclear. Here, we…
2. Human recombinant protein C for severe sepsis and septic shock in adult and paediatric patients
DEFF Research Database (Denmark)
Martí-Carvajal, Arturo J; Solà, Ivan; Gluud, Christian; Lathyris, Dimitrios; Cardona, Andrés Felipe
2012-01-01
Sepsis is a common and frequently fatal condition. Human recombinant activated protein C (APC) has been introduced to reduce the high risk of death associated with severe sepsis or septic shock. This systematic review is an update of a Cochrane review originally published in 2007....
3. Gene × Smoking Interactions on Human Brain Gene Expression: Finding Common Mechanisms in Adolescents and Adults
Science.gov (United States)
Wolock, Samuel L.; Yates, Andrew; Petrill, Stephen A.; Bohland, Jason W.; Blair, Clancy; Li, Ning; Machiraju, Raghu; Huang, Kun; Bartlett, Christopher W.
2013-01-01
Background: Numerous studies have examined gene × environment interactions (G × E) in cognitive and behavioral domains. However, these studies have been limited in that they have not been able to directly assess differential patterns of gene expression in the human brain. Here, we assessed G × E interactions using two publically available datasets…
4. Mechanisms underlying the rules for associative plasticity at adult human neocortical synapses
NARCIS (Netherlands)
M.B. Verhoog (Matthijs); N.A. Goriounova (Natalia); J. Obermayer (Joshua); J. Stroeder (Jasper); J.J. Johannes Hjorth (J.); G. Testa-Silva (Guilherme); J.C. Baayen; C.P.J. de Kock (Christiaan); R.M. Meredith (Rhiannon); H.D. Mansvelder (Huibert)
2013-01-01
textabstractThe neocortex in our brain stores long-term memories by changing the strength of connections between neurons. To date, the rules and mechanisms that govern activity-induced synaptic changes at human cortical synapses are poorly understood and have not been studied directly at a cellular
5. Examining the Relationship between Childhood Animal Cruelty Motives and Recurrent Adult Violent Crimes toward Humans
Science.gov (United States)
Overton, Joshua C.; Hensley, Christopher; Tallichet, Suzanne E.
2012-01-01
Few researchers have studied the predictive ability of childhood animal cruelty motives as they are associated with later recurrent violence toward humans. Based on a sample of 180 inmates at one medium- and one maximum-security prison in a Southern state, the present study examines the relationship among several retrospectively identified motives…
6. Helios defines T cells being driven to tolerance in the periphery and thymus.
Science.gov (United States)
Ross, Ellen M; Bourges, Dorothée; Hogan, Thea V; Gleeson, Paul A; van Driel, Ian R
2014-07-01
The expression of the Ikaros transcription factor family member, Helios, has been shown to be associated with T-cell tolerance in both the thymus and the periphery. To better understand the importance of Helios in tolerance pathways, we have examined the expression of Helios in TCR-transgenic T cells specific for the gastric H(+) /K(+) ATPase, the autoantigen target in autoimmune gastritis. Analysis of H(+) /K(+) ATPase-specific T cells in mice with different patterns of H(+) /K(+) ATPase expression revealed that, in addition to the expression of Helios in CD4(+) Foxp3(+) regulatory T (Treg) cells, Helios is expressed by a large proportion of CD4(+) Foxp3(-) T cells in both the thymus and the paragastric lymph node (PgLN), which drains the stomach. In the thymus, Helios was expressed by H(+) /K(+) ATPase-specific thymocytes that were undergoing negative selection. In the periphery, Helios was expressed in H(+) /K(+) ATPase-specific CD4(+) T cells following H(+) /K(+) ATPase presentation and was more highly expressed when T-cell activation occurred in the absence of inflammation. Analysis of purified H(+) /K(+) ATPase-specific CD4(+) Foxp3(-) Helios(+) T cells demonstrated that they were functionally anergic. These results demonstrate that Helios is expressed by thymic and peripheral T cells that are being driven to tolerance in response to a genuine autoantigen. PMID:24740292
7. Primary neuroendocrine carcinoma of thymus: A rare cause of Cushing′s syndrome
Directory of Open Access Journals (Sweden)
Arora Raman
2010-01-01
Full Text Available Thymomas constitute majority of the thymic neoplasms. In contrast, neuroendocrine tumors (carcinoid and neuroendocrine carcinoma of thymus are extremely rare. Thymic carcinoids may present rarely with Cushing′s syndrome due to the ectopic production of adrenocorticotropic hormone (ACTH. Recognition of this association is imperative for appropriate management of patients. We describe three cases of rare atypical carcinoid tumor (neuroendocrine carcinoma of the thymus. Case 1, of a 26-year-old man presenting with Cushing′s syndrome, case 2 - a 23-year-old female with Cushingoid features, and Case 3 - a 39-year-old man complaining of progressively worsening dyspnea. Computed tomography (CT scans of chest in all three patients revealed anterior mediastinal mass. Excision of tumors and histological examination of the three tumors showed a carcinoid tumor with nuclear pleomorphism, increased mitotic activity and focal necrosis. The features suggested a diagnosis of atypical carcinoid tumor in all the three cases. The tumor cells in Cases 1 and 2 showed focal immunohistochemical staining for ACTH. Atypical carcinoid (neuroendocrine carcinoma, well-differentiated and moderately-differentiated of the thymus is a rare thymic tumor which carries a worse prognosis compared to thymoma and requires aggressive therapy. Hence, an accurate diagnosis is essential.
8. Cortisol decreases 2[[sup 125]I] iodomelatonin binding sites in the duck thymus
Energy Technology Data Exchange (ETDEWEB)
Poon, A.M.S.; Liu, Z.M.; Tang, F.; Pang, S.F. (Univ. of Hong Kong (China))
1994-03-01
The immunosuppressive effect of chronic glucocorticoid treatment on 2[[sup 125]I] iodomelatonin binding in the duck thymus was studied. Two-week-old ducks were injected intraperitoneally with either 1 mg of cortisol per day (experimental group) or an equivalent volume of vehicle (control group) in the middle of the light period for seven days. 2[[sup 125]I] iodomelatonin binding assays were performed on thymic membranes. Cortisol injection reduced the body weight gain, size of the bursa of Fabricius and absolute weights of the primary lymphoid organs but had no effect on the spleen weights. The relative weights of the spleen were increased while those of the primary lymphoid organs were unchanged. The density of the thymus 2[[sup 125]I] iodomelatonin binding sites was decreased while the affinity was not affected. The modulation of the thymic 2[[sup 125]I] iodomelatonin binding sites by changes in the immune status of the duck suggests that these binding sites represent physiologically relevant melatonin receptors and that melatonin exerts its action on the lymphoid tissues directly. The authors findings support the hypothesis that the thymus is the target site for the immunomodulatory interactions between the pineal melatonin and the adrenal steroids. A possible inhibitory influence of adrenal steroids on the immuno-enhancing effect of melatonin is also suggested. 34 refs., 3 tabs.
9. Quantitative analysis of DNA methylation at all human imprinted regions reveals preservation of epigenetic stability in adult somatic tissue
Directory of Open Access Journals (Sweden)
Woodfine Kathryn
2011-01-01
Full Text Available Abstract Background Genes subject to genomic imprinting are mono-allelically expressed in a parent-of-origin dependent manner. Each imprinted locus has at least one differentially methylated region (DMR which has allele specific DNA methylation and contributes to imprinted gene expression. Once DMRs are established, they are potentially able to withstand normal genome reprogramming events that occur during cell differentiation and germ-line DMRs are stably maintained throughout development. These DMRs, in addition to being either maternally or paternally methylated, have differences in whether methylation was acquired in the germ-line or post fertilization and are present in a variety of genomic locations with different Cytosine-phosphate guanine (CpG densities and CTCF binding capacities. We therefore examined the stability of maintenance of DNA methylation imprints and determined the normal baseline DNA methylation levels in several adult tissues for all imprinted genes. In order to do this, we first developed and validated 50 highly specific, quantitative DNA methylation pyrosequencing assays for the known DMRs associated with human imprinted genes. Results Remarkable stability of the DNA methylation imprint was observed in all germ-line DMRs and paternally methylated somatic DMRs (which maintained average methylation levels of between 35% - 65% in all somatic tissues, independent of gene expression. Maternally methylated somatic DMRs were found to have more variation with tissue specific methylation patterns. Most DMRs, however, showed some intra-individual variability for DNA methylation levels in peripheral blood, suggesting that more than one DMR needs to be examined in order to get an overall impression of the epigenetic stability in a tissue. The plasticity of DNA methylation at imprinted genes was examined in a panel of normal and cancer cell lines. All cell lines showed changes in DNA methylation, especially at the paternal germ
10. FASH and MASH: female and male adult human phantoms based on polygon mesh surfaces: II. Dosimetric calculations
International Nuclear Information System (INIS)
Female and male adult human phantoms, called FASH (Female Adult meSH) and MASH (Male Adult meSH), have been developed in the first part of this study using 3D animation software and anatomical atlases to replace the image-based FAX06 and the MAX06 voxel phantoms. 3D modelling methods allow for phantom development independent from medical images of patients, volunteers or cadavers. The second part of this study investigates the dosimetric implications for organ and tissue equivalent doses due to the anatomical differences between the new and the old phantoms. These differences are mainly caused by the supine position of human bodies during scanning in order to acquire digital images for voxel phantom development. Compared to an upright standing person, in image-based voxel phantoms organs are often coronally shifted towards the head and sometimes the sagittal diameter of the trunk is reduced by a gravitational change of the fat distribution. In addition, volumes of adipose and muscle tissue shielding internal organs are sometimes too small, because adaptation of organ volumes to ICRP-based organ masses often occurs at the expense of general soft tissues, such as adipose, muscle or unspecified soft tissue. These effects have dosimetric consequences, especially for partial body exposure, such as in x-ray diagnosis, but also for whole body external exposure and for internal exposure. Using the EGSnrc Monte Carlo code, internal and external exposure to photons and electrons has been simulated with both pairs of phantoms. The results show differences between organ and tissue equivalent doses for the upright standing FASH/MASH and the image-based supine FAX06/MAX06 phantoms of up to 80% for external exposure and up to 100% for internal exposure. Similar differences were found for external exposure between FASH/MASH and REGINA/REX, the reference voxel phantoms of the International Commission on Radiological Protection. Comparison of effective doses for external photon
11. Age-Dependent Changes in Geometry, Tissue Composition and Mechanical Properties of Fetal to Adult Cryopreserved Human Heart Valves
Science.gov (United States)
van Geemen, Daphne; Soares, Ana L. F.; Oomen, Pim J. A.; Driessen-Mol, Anita; Janssen-van den Broek, Marloes W. J. T.; van den Bogaerdt, Antoon J.; Bogers, Ad J. J. C.; Goumans, Marie-José T. H.; Baaijens, Frank P. T.; Bouten, Carlijn V. C.
2016-01-01
There is limited information about age-specific structural and functional properties of human heart valves, while this information is key to the development and evaluation of living valve replacements for pediatric and adolescent patients. Here, we present an extended data set of structure-function properties of cryopreserved human pulmonary and aortic heart valves, providing age-specific information for living valve replacements. Tissue composition, morphology, mechanical properties, and maturation of leaflets from 16 pairs of structurally unaffected aortic and pulmonary valves of human donors (fetal-53 years) were analyzed. Interestingly, no major differences were observed between the aortic and pulmonary valves. Valve annulus and leaflet dimensions increase throughout life. The typical three-layered leaflet structure is present before birth, but becomes more distinct with age. After birth, cell numbers decrease rapidly, while remaining cells obtain a quiescent phenotype and reside in the ventricularis and spongiosa. With age and maturation–but more pronounced in aortic valves–the matrix shows an increasing amount of collagen and collagen cross-links and a reduction in glycosaminoglycans. These matrix changes correlate with increasing leaflet stiffness with age. Our data provide a new and comprehensive overview of the changes of structure-function properties of fetal to adult human semilunar heart valves that can be used to evaluate and optimize future therapies, such as tissue engineering of heart valves. Changing hemodynamic conditions with age can explain initial changes in matrix composition and consequent mechanical properties, but cannot explain the ongoing changes in valve dimensions and matrix composition at older age. PMID:26867221
12. Age-Dependent Changes in Geometry, Tissue Composition and Mechanical Properties of Fetal to Adult Cryopreserved Human Heart Valves.
Science.gov (United States)
van Geemen, Daphne; Soares, Ana L F; Oomen, Pim J A; Driessen-Mol, Anita; Janssen-van den Broek, Marloes W J T; van den Bogaerdt, Antoon J; Bogers, Ad J J C; Goumans, Marie-José T H; Baaijens, Frank P T; Bouten, Carlijn V C
2016-01-01
There is limited information about age-specific structural and functional properties of human heart valves, while this information is key to the development and evaluation of living valve replacements for pediatric and adolescent patients. Here, we present an extended data set of structure-function properties of cryopreserved human pulmonary and aortic heart valves, providing age-specific information for living valve replacements. Tissue composition, morphology, mechanical properties, and maturation of leaflets from 16 pairs of structurally unaffected aortic and pulmonary valves of human donors (fetal-53 years) were analyzed. Interestingly, no major differences were observed between the aortic and pulmonary valves. Valve annulus and leaflet dimensions increase throughout life. The typical three-layered leaflet structure is present before birth, but becomes more distinct with age. After birth, cell numbers decrease rapidly, while remaining cells obtain a quiescent phenotype and reside in the ventricularis and spongiosa. With age and maturation-but more pronounced in aortic valves-the matrix shows an increasing amount of collagen and collagen cross-links and a reduction in glycosaminoglycans. These matrix changes correlate with increasing leaflet stiffness with age. Our data provide a new and comprehensive overview of the changes of structure-function properties of fetal to adult human semilunar heart valves that can be used to evaluate and optimize future therapies, such as tissue engineering of heart valves. Changing hemodynamic conditions with age can explain initial changes in matrix composition and consequent mechanical properties, but cannot explain the ongoing changes in valve dimensions and matrix composition at older age. PMID:26867221
13. Redifferentiation of insulin-secreting cells after in vitro expansion of adult human pancreatic islet tissue
International Nuclear Information System (INIS)
Cellular replacement therapy holds promise for the treatment of diabetes mellitus but donor tissue is severely limited. Therefore, we investigated whether insulin-secreting cells could be differentiated in vitro from a monolayer of cells expanded from human donor pancreatic islets. We describe a three-step culture protocol that allows for the efficient generation of insulin-producing cell clusters from in vitro expanded, hormone-negative cells. These clusters express insulin at levels of up to 34% that of average freshly isolated human islets and secrete C-peptide upon membrane depolarization. They also contain cells expressing the other major islet hormones (glucagon, somatostatin, and pancreatic polypeptide). The source of the newly differentiated endocrine cells could either be indigenous stem/progenitor cells or the proliferation-associated dedifferentiation and subsequent redifferentiation of mature endocrine cells. The in vitro generated cell clusters may be efficacious in providing islet-like tissue for transplantation into diabetic recipients
14. Adult Human Nasal Mesenchymal-Like Stem Cells Restore Cochlear Spiral Ganglion Neurons After Experimental Lesion
OpenAIRE
Bas, Esperanza; Van De Water, Thomas R.; Lumbreras, Vicente; Rajguru, Suhrud; Goss, Garrett; Hare, Joshua M.; Goldstein, Bradley J.
2013-01-01
A loss of sensory hair cells or spiral ganglion neurons from the inner ear causes deafness, affecting millions of people. Currently, there is no effective therapy to repair the inner ear sensory structures in humans. Cochlear implantation can restore input, but only if auditory neurons remain intact. Efforts to develop stem cell-based treatments for deafness have demonstrated progress, most notably utilizing embryonic-derived cells. In an effort to bypass limitations of embryonic or induced p...
15. Nestin Expression in Embryonic and Adult Human Teeth under Normal and Pathological Conditions
OpenAIRE
2000-01-01
Nestin is an intermediate filament most related to neurofilaments and expressed predominantly in the developing nervous system and muscles. In the present study we examined the in vivo distribution of nestin in human teeth during embryonic development and in permanent teeth under normal and pathological conditions. The results show that nestin is first expressed at the bell stage and that its distribution is restricted in pulpal cells located at the cusp area of the fetal teeth. In young perm...
16. The Therapeutic Effect of Human Adult Stem Cells Derived from Adipose Tissue in Endotoxemic Rat Model
OpenAIRE
Soyoung Shin, Yonggoo Kim, Sikyoung Jeong, Sungyoup Hong, Insoo Kim, Woonjeong Lee, Seungphil Choi
2013-01-01
Excessive systemic inflammation following sepsis, trauma or burn could lead to multi-organ damage and death. Bone marrow stromal cells (BMSCs), commonly referred to as mesenchymal stem cells (MSCs), has been studied in several immune-associated diseases in human and animal by modulating the inflammatory response. Adipose tissue derived mesenchymal stem cells (ATSCs), which can be obtained more easily, compared with BMSCs, has emerged as an attractive alternative MSCs source for cell therapy. ...
17. The Therapeutic Effect of Human Adult Stem Cells Derived from Adipose Tissue in Endotoxemic Rat Model
OpenAIRE
Shin, Soyoung; Kim, Yonggoo; Jeong, Sikyoung; Hong, Sungyoup; Kim, Insoo; Lee, Woonjeong; Choi, Seungphil
2012-01-01
Excessive systemic inflammation following sepsis, trauma or burn could lead to multi-organ damage and death. Bone marrow stromal cells (BMSCs), commonly referred to as mesenchymal stem cells (MSCs), has been studied in several immune-associated diseases in human and animal by modulating the inflammatory response. Adipose tissue derived mesenchymal stem cells (ATSCs), which can be obtained more easily, compared with BMSCs, has emerged as an attractive alternative MSCs source for cell therapy. ...
18. Tai Chi Chuan Optimizes the Functional Organization of the Intrinsic Human Brain Architecture in Older Adults
OpenAIRE
Jing Luo; Xi-Nian Zuo
2014-01-01
Whether Tai Chi Chuan (TCC) can influence the intrinsic functional architecture of the human brain remains unclear. To examine TCC-associated changes in functional connectomes, resting-state functional magnetic resonance images were acquired from 40 older individuals including 22 experienced TCC practitioners (experts) and 18 demographically matched TCC-naïve healthy controls, and their local functional homogeneities across the cortical mantle were compared. Compared to the controls, the TCC ...
19. Tai Chi Chuan optimizes the functional organization of the intrinsic human brain architecture in older adults
OpenAIRE
Wei, Gao-Xia; Dong, Hao-Ming; Yang, Zhi; Luo, Jing; Zuo, Xi-Nian
2014-01-01
Whether Tai Chi Chuan (TCC) can influence the intrinsic functional architecture of the human brain remains unclear. To examine TCC-associated changes in functional connectomes, resting-state functional magnetic resonance images were acquired from 40 older individuals including 22 experienced TCC practitioners (experts) and 18 demographically matched TCC-naïve healthy controls, and their local functional homogeneities across the cortical mantle were compared. Compared to the controls, the TCC ...
20. Pharmacokinetic Interaction of Abacavir (1592U89) and Ethanol in Human Immunodeficiency Virus-Infected Adults
OpenAIRE
McDowell, James A.; Chittick, Gregory E.; Stevens, Cristina Pilati; Edwards, Kathleen D.; Stein, Daniel S.
2000-01-01
While in vitro results at clinically relevant concentrations do not predict abacavir (1592U89) interactions with drugs highly metabolized by cytochrome P450, the potential does exist for a pharmacokinetic interaction between abacavir and ethanol, as both are metabolized by alcohol dehydrogenase. Twenty-five subjects were enrolled in an open-label, randomized, three-way-crossover, phase I study of human immunodeficiency virus-infected male subjects. The three treatments were administration of ...
1. The impact of body worlds on adult visitors' knowledge on human anatomy: A preliminary study.
Science.gov (United States)
Fonseca, Guilherme R B C; Finn, Gabrielle M
2016-05-01
Body Worlds is an anatomical exhibition that shows human remains to the public. It has been considered controversial since it raises ethical tensions and issues. However, organizers and supporters of Body Worlds have claimed the exhibition is intended to promote visitors' understanding over the human body. Despite these claims, no studies were found that support or refute the hypothesis that a visit to Body Worlds increases the public's objective knowledge on human anatomy. Consequently, the objective of this study was to determine the impact of Body Worlds on anatomical knowledge. We constructed and delivered a questionnaire to both a previsit random sample and a postvisit random sample of visitors of Body Worlds' event Facets of Life, in Berlin. The questionnaire was available in both English and German languages and contained (a) basic sociodemographic questions and (b) a valid and reliable anatomy quiz. The quiz consisted of 16 multiple-choice questions that assessed the ability to identify the location of major anatomical structures on the human body. Average scores achieved on the quiz by the postvisit sample (X¯= 9.08, s = 2.48, n = 164) were significantly higher (unpaired t = 3.3957, P = 0.0008) than those achieved by the previsit sample (X¯= 8.11, s = 2.69, n = 167). Our results suggest that a visit to Body Worlds' event Facets of Life may have a beneficial effect in anatomical knowledge. However, further studies with better empirical designs and fewer limitations are needed to confirm our results. Clin. Anat. 29:439-445, 2016. © 2016 Wiley Periodicals, Inc. PMID:26789643
2. Cyclophilin D-Sensitive Mitochondrial Permeability Transition in Adult Human Brain and Liver Mitochondria
OpenAIRE
Hansson, Magnus; Morota, Saori; Li CHEN; Matsuyama, Nagahisa; SUZUKI, YOSHIAKI; Nakajima, Satoshi; Tanoue, Tadashi; Omi, Akibumi; Shibasaki, Futoshi; Shimazu, Motohide; IKEDA, Yukio; Uchino, Hiroyuki; Elmér, Eskil
2011-01-01
The mitochondrial permeability transition (mPT) is considered to be a major cause of cell death under a variety of pathophysiological conditions of the central nervous system (CNS) and other organs. Pharmacological inhibition or genetic knockout of the matrix protein cyclophilin D (CypD) prevents mPT and cell degeneration in several models of brain injury. If these findings in animal models are translatable to human disease, pharmacological inhibition of mPT offers a promising therapeutic tar...
3. Category training induces cross-modal object representations in the adult human brain.
OpenAIRE
van der Linden, Marieke; van Turennout, Miranda; Fernández, Guillén
2011-01-01
The formation of cross-modal object representations was investigated using a novel paradigm that was previously successful in establishing unimodal visual category learning in monkeys and humans. The stimulus set consisted of six categories of bird shapes and sounds that were morphed to create different exemplars of each category. Subjects learned new cross-modal bird categories using a one-back task. Over time, the subjects became faster and more accurate in categorizing the birds. After 3 d...
4. Habituation of adult Magellanic penguins to human visitation as expressed through behavior and corticosterone secretion.
Science.gov (United States)
Walker, Brian G; Boersma, P Dee; Wingfield, John C
2006-02-01
Ecotourism is increasing worldwide; hence, it is important to know how wildlife are affected behaviorally and physiologically by human visitation. We studied the effects of human visitation on the Magellanic Penguins (Spheniscus magellanicus) at Punta Tombo, Argentina, by monitoring changes in defensive head turns and plasma corticosterone (a hormone secreted in response to stress) for penguins with and without a history of tourist visitation. Habituation to human visitation was rapid. In penguins with no previous exposure to tourists, the number of defensive head turns and level of plasma corticosterone decreased significantly within 5 days of one 15-minute visit/day. Penguins living in tourist-visited and undisturbed areas secreted more corticosterone when captured and restrained than penguins visited by a person. Penguins in tourist areas, however did not show as strong a corticosterone response to capture and restraint as did penguins in areas without tourists. This difference was due to a decreased capability of the adrenocortical tissue to secrete corticosterone in tourist-visited birds. Although our data show no direct negative effects of tourism on Magellanic Penguins at Punta Tombo, consequences of a modification of physiological capabilities (e.g., adrenocortical function) may not become apparent until much later in life. The physiological differences between tourist-visited and undisturbed groups of Magellanic Penguins emphasize the importance of monitoring the effects of anthropogenic disturbances on wildlife at multiple levels. PMID:16909667
5. Is the cultural transmission of irrelevant tool actions in adult humans (Homo sapiens best explained as the result of an evolved conformist bias?
Directory of Open Access Journals (Sweden)
Nicola McGuigan
6. Enhancement Of The T Cell Mediated Hypersensitivity Reaction By Thymus Extract In GAMMA Irradiated BALB/C Mice
International Nuclear Information System (INIS)
7. Rapid and Efficient Direct Conversion of Human Adult Somatic Cells into Neural Stem Cells by HMGA2/let-7b
Directory of Open Access Journals (Sweden)
Kyung-Rok Yu
2015-01-01
Full Text Available A recent study has suggested that fibroblasts can be converted into mouse-induced neural stem cells (miNSCs through the expression of defined factors. However, successful generation of human iNSCs (hiNSCs has proven challenging to achieve. Here, using microRNA (miRNA expression profile analyses, we showed that let-7 microRNA has critical roles for the formation of PAX6/NESTIN-positive colonies from human adult fibroblasts and the proliferation and self-renewal of hiNSCs. HMGA2, a let-7-targeting gene, enables induction of hiNSCs that displayed morphological/molecular features and in vitro/in vivo differentiation potential similar to H9-derived NSCs. Interestingly, HMGA2 facilitated the efficient conversion of senescent somatic cells or blood CD34+ cells into hiNSCs through an interaction with SOX2, whereas other combinations or SOX2 alone showed a limited conversion ability. Taken together, these findings suggest that HMGA2/let-7 facilitates direct reprogramming toward hiNSCs in minimal conditions and maintains hiNSC self-renewal, providing a strategy for the clinical treatment of neurological diseases.
8. Protonation states of histidine and other key residues in deoxy normal human adult hemoglobin by neutron protein crystallography
International Nuclear Information System (INIS)
Using neutron diffraction analysis, the protonation states of 35 of 38 histidine residues were determined for the deoxy form of normal human adult hemoglobin. Distal and buried histidines may contribute to the increased affinity of the deoxy state for hydrogen ions and its decreased affinity for oxygen compared with the oxygenated form. The protonation states of the histidine residues key to the function of deoxy (T-state) human hemoglobin have been investigated using neutron protein crystallography. These residues can reversibly bind protons, thereby regulating the oxygen affinity of hemoglobin. By examining the OMIT Fo − Fc and 2Fo − Fc neutron scattering maps, the protonation states of 35 of the 38 His residues were directly determined. The remaining three residues were found to be disordered. Surprisingly, seven pairs of His residues from equivalent α or β chains, αHis20, αHis50, αHis58, αHis89, βHis63, βHis143 and βHis146, have different protonation states. The protonation of distal His residues in the α1β1 heterodimer and the protonation of αHis103 in both subunits demonstrates that these residues may participate in buffering hydrogen ions and may influence the oxygen binding. The observed protonation states of His residues are compared with their ΔpKa between the deoxy and oxy states. Examination of inter-subunit interfaces provided evidence for interactions that are essential for the stability of the deoxy tertiary structure
9. Pegylated Long-Acting Human Growth Hormone Possesses a Promising Once-Weekly Treatment Profile, and Multiple Dosing Is Well Tolerated in Adult Patients with Growth Hormone Deficiency
DEFF Research Database (Denmark)
Søndergaard, Esben; Klose, Marianne; Hansen, Mette;
2011-01-01
Background: Recombinant human GH (rhGH) replacement therapy in children and adults currently requires daily sc injections for several years or lifelong, which may be both inconvenient and distressing for patients. NNC126-0083 is a pegylated rhGH developed for once-weekly administration. Objectives...
10. Relative Efficacy of a Pregnancy, Sexually Transmitted Infection, or Human Immunodeficiency Virus Prevention--Focused Intervention on Changing Sexual Risk Behavior among Young Adults
Science.gov (United States)
Norton, Wynne E.; Fisher, Jeffrey D.; Amico, K. Rivet; Dovidio, John F.; Johnson, Blair T.
2012-01-01
Objectives: Despite findings suggesting that young adults are more concerned about experiencing an unplanned pregnancy or contracting a sexually transmitted infection (STI) than becoming human immunodeficiency virus (HIV) infected, no empirical work has investigated whether the specific focus of an intervention may be more or less efficacious at…
11. Erythroid activator NF-E2, TAL1 and KLF1 play roles in forming the LCR HSs in the human adult β-globin locus.
Science.gov (United States)
Kim, Yea Woon; Yun, Won Ju; Kim, AeRi
2016-06-01
The β-like globin genes are developmental stage specifically transcribed in erythroid cells. The transcription of the β-like globin genes requires erythroid specific activators such as GATA-1, NF-E2, TAL1 and KLF1. However, the roles of these activators have not fully elucidated in transcription of the human adult β-globin gene. Here we employed hybrid MEL cells (MEL/ch11) where a human chromosome containing the β-globin locus is present and the adult β-globin gene is highly transcribed by induction. The roles of erythroid specific activators were analyzed by inhibiting the expression of NF-E2, TAL1 or KLF1 in MEL/ch11 cells. The loss of each activator decreased the transcription of human β-globin gene, locus wide histone hyperacetylation and the binding of other erythroid specific activators including GATA-1, even though not affecting the expression of other activators. Notably, sensitivity to DNase I was reduced in the locus control region (LCR) hypersensitive sites (HSs) with the depletion of activators. These results indicate that NF-E2, TAL1 and KLF1, all activators play a primary role in HSs formation in the LCR. It might contribute to the transcription of human adult β-globin gene by allowing the access of activators and cofactors. The roles of activators in the adult β-globin locus appear to be different from the roles in the early fetal locus. PMID:27026582
12. Metabolic profile in growth hormone-deficient (GHD) adults after long-term recombinant human growth hormone (rhGH) therapy
NARCIS (Netherlands)
Claessen, K.M.; Appelman-Dijkstra, N.M.; Adoptie, D.M.; Roelfsema, F.; Smit, J.W.A.; Biermasz, N.R.; Pereira, A.M.
2013-01-01
BACKGROUND: The metabolic effects of recombinant human GH (rhGH) therapy in adults are well-documented in the short term. The effects of long-term rhGH therapy beyond 5 yr on metabolic parameters are presently unknown. OBJECTIVE: The aim of the study was to evaluate the long-term effects of rhGH tre
13. Neuron-enriched gene expression patterns are regionally anti-correlated with oligodendrocyte-enriched patterns in the adult mouse and human brain
Directory of Open Access Journals (Sweden)
Powell PatrickChengTan
2013-02-01
Full Text Available An important goal in neuroscience is to understand gene expression patterns in the brain. The recent availability of comprehensive and detailed expression atlases for mouse and human creates opportunities to discover global patterns and perform cross-species comparisons. Recently we reported that the major source of variation in gene transcript expression in the adult normal mouse brain can be parsimoniously explained as reflecting regional variation in glia-to-neuron ratios, and is correlated with degree of connectivity and location in the brain along the anterior-posterior axis. Here we extend this investigation to two gene expression assays of adult normal human brains that consisted of over 300 brain region samples, and perform comparative analyses of brain-wide expression patterns to the mouse. We performed principal components analysis (PCA on the regional gene expression of the adult human brain to identify the expression pattern that has the largest variance. As in the mouse, we observed that the first principal component is composed of two anti-correlated patterns enriched in oligodendrocyte and neuron markers respectively. However, we also observed interesting discordant patterns between the two species. For example, a few mouse neuron markers show expression patterns that are more correlated with the human oligodendrocyte-enriched pattern and vice-versa. In conclusion, our work provides insights into human brain function and evolution by probing global relationships between regional cell type marker expression patterns in the human and mouse brain.
14. Rearing history and allostatic load in adult western lowland gorillas (Gorilla gorilla gorilla) in human care.
Science.gov (United States)
Edes, Ashley N; Wolfe, Barbara A; Crews, Douglas E
2016-03-01
Disrupted rearing history is a psychological and physical stressor for nonhuman primates, potentially resulting in multiple behavioral and physiological changes. As a chronic, soma-wide stressor, altered rearing may be best assessed using a holistic tool such as allostatic load (AL). In humans, AL estimates outcomes of lifetime stress-induced damage. We predicted mother-reared gorillas would have lower AL than nursery-reared and wild-caught conspecifics. We estimated AL for 27 gorillas housed at the Columbus Zoo and Aquarium between 1956 and 2014. AL estimates were calculated using biomarkers obtained during previous anesthetic events. Biomarkers in the high-risk quartile were counted toward a gorilla's AL. Rearing history was categorized as mother-reared, nursery-reared, and wild-caught. Using ANCOVA, rearing history and AL are significantly associated when age and sex are entered as covariates. Wild-caught gorillas have significantly higher AL than mother-reared gorillas. Neither wild-caught nor mother-reared gorillas are significantly different from nursery-reared gorillas. When examined by sex, males of all rearing histories have significantly lower AL than females. We suggest males face few stressors in human care and ill effects of rearing history do not follow. Wild-caught females have significantly higher AL than mother-reared females, but neither is significantly different from nursery-reared females. Combined with our previous work on AL in this group, wherein females had twofold higher AL than males, we suggest females in human care face more stressors than males. Disrupted rearing history may exacerbate effects of these stressors. Providing opportunities for females to choose their distance from males may help reduce their AL. Zoo Biol. 35:167-173, 2016. © 2016 Wiley Periodicals, Inc. PMID:26881840
15. Energy expenditure during sleep, sleep deprivation and sleep following sleep deprivation in adult humans
OpenAIRE
Jung, Christopher M.; Melanson, Edward L.; Frydendall, Emily J; Perreault, Leigh; Eckel, Robert H; Wright, Kenneth P
2010-01-01
Sleep has been proposed to be a physiological adaptation to conserve energy, but little research has examined this proposed function of sleep in humans. We quantified effects of sleep, sleep deprivation and recovery sleep on whole-body total daily energy expenditure (EE) and on EE during the habitual day and nighttime. We also determined effects of sleep stage during baseline and recovery sleep on EE. Seven healthy participants aged 22 ± 5 years (mean ± s.d.) maintained ∼8 h per night sleep s...
16. Fluorescent antibody studies of alpha-1-antitrypsin in adult human lung
International Nuclear Information System (INIS)
The distribution of alpha-1-antitrypsin in frozen sections prepared from four specimens of human lung was determined by the indirect fluorescent antibody technique. Three of the specimens were obtained directly from surgical procedures and were peripheral tissue excised with tumors. Specific fluorescence for alpha-1-antitrypsin was observed lining the terminal airways and alveoli throughout the sections from two of the cases. In the other cases, a few focal areas of specific fluorescence were observed. The results of this study indicate that alpha-1-antitrypsin may be distributed in lung in association with pulmonary surfactant and that local tissue concentrations of alpha-1-antitrypsin are variable. (U.S.)
17. A computer model of the artificially ventilated human respiratory system in adult intensive care.
Science.gov (United States)
Wilson, A J; Murphy, C M; Brook, B S; Breen, D; Miles, A W; Tilley, D G
2009-11-01
A multi-technique approach to modelling artificially ventilated patients on the adult general intensive care unit (ICU) is proposed. Compartmental modelling techniques were used to describe the mechanical ventilator and the flexible hoses that connect it to the patient. 3D CFD techniques were used to model flow in the major airways and a Windkessel style balloon model was used to model the mechanical properties of the lungs. A multi-compartment model of the lung based on bifurcating tree structures representing the conducting airways and pulmonary circulation allowed lung disease to be modelled in terms of altered V/Q ratios within a lognormal distribution of values and it is from these that gas exchange was determined. A compartmental modelling tool, Bathfp, was used to integrate the different modelling techniques into a single model. The values of key parameters in the model could be obtained from measurements on patients in an ICU whilst a sensitivity analysis showed that the model was insensitive to the value of other parameters within it. Measured and modelled values for arterial blood gases and airflow parameters are compared for 46 ventilator settings obtained from 6 ventilator dependent patients. The results show correlation coefficients of 0.88 and 0.85 for the arterial partial pressures of the O(2) and CO(2), respectively (p<0.01) and of 0.99 and 0.96 for upper airway pressure and tidal volume, respectively (p<0.01). The difference between measured and modelled values was large in physiological terms, suggesting that some optimisation of the model is required. PMID:19699134
18. Metabolic fate of dietary carnitine in human adults: Identification and quantification of urinary and fecal metabolites
Energy Technology Data Exchange (ETDEWEB)
Rebouche, C.J.; Chenard, C.A. (Univ. of Iowa College of Medicine, Iowa City (USA))
1991-04-01
Results of kinetic and pharmacokinetic studies have suggested that dietary carnitine is not totally absorbed and is in part degraded in the gastrointestinal tract of humans. To determine the metabolic fate of dietary carnitine in humans, we administered orally a tracer dose of methyl-{sup 3}H L-carnitine with a meal to subjects who had been adapted to a low-carnitine diet or a high-carnitine diet. Urinary and fecal excretion of radiolabeled carnitine and metabolites was monitored for 5 to 11 d following administration of the test dose. Total radioactive metabolites excreted ranged from 13 to 34% (low carnitine diet) and 27 to 46% (high carnitine diet) of the ingested tracer. Major metabolites found were ({sup 3}H)trimethylamine N-oxide (8 to 39% of the administered dose; excreted primarily in urine) and ({sup 3}H)gamma-butyrobetaine (0.09 to 8% of the administered dose; excreted primarily in feces). Urinary excretion of total carnitine was 42 to 95% (high carnitine diet) and 190 to 364% (low carnitine diet) of intake. These results indicate that oral carnitine is 54 to 87% bioavailable from normal Western diets; the percentage of intake absorbed is related to the quantity ingested.
19. Metabolic fate of dietary carnitine in human adults: Identification and quantification of urinary and fecal metabolites
International Nuclear Information System (INIS)
Results of kinetic and pharmacokinetic studies have suggested that dietary carnitine is not totally absorbed and is in part degraded in the gastrointestinal tract of humans. To determine the metabolic fate of dietary carnitine in humans, we administered orally a tracer dose of methyl-3H L-carnitine with a meal to subjects who had been adapted to a low-carnitine diet or a high-carnitine diet. Urinary and fecal excretion of radiolabeled carnitine and metabolites was monitored for 5 to 11 d following administration of the test dose. Total radioactive metabolites excreted ranged from 13 to 34% (low carnitine diet) and 27 to 46% (high carnitine diet) of the ingested tracer. Major metabolites found were [3H]trimethylamine N-oxide (8 to 39% of the administered dose; excreted primarily in urine) and [3H]gamma-butyrobetaine (0.09 to 8% of the administered dose; excreted primarily in feces). Urinary excretion of total carnitine was 42 to 95% (high carnitine diet) and 190 to 364% (low carnitine diet) of intake. These results indicate that oral carnitine is 54 to 87% bioavailable from normal Western diets; the percentage of intake absorbed is related to the quantity ingested
20. The Therapeutic Effect of Human Adult Stem Cells Derived from Adipose Tissue in Endotoxemic Rat Model
Directory of Open Access Journals (Sweden)
Soyoung Shin, Yonggoo Kim, Sikyoung Jeong, Sungyoup Hong, Insoo Kim, Woonjeong Lee, Seungphil Choi
2013-01-01
Full Text Available Excessive systemic inflammation following sepsis, trauma or burn could lead to multi-organ damage and death. Bone marrow stromal cells (BMSCs, commonly referred to as mesenchymal stem cells (MSCs, has been studied in several immune-associated diseases in human and animal by modulating the inflammatory response. Adipose tissue derived mesenchymal stem cells (ATSCs, which can be obtained more easily, compared with BMSCs, has emerged as an attractive alternative MSCs source for cell therapy. We investigated the therapeutic effects of human ATSCs (hATSCs in endotoxemic rat model and their capacity to modulate the inflammatory response. Endotoxemia was induced with Lipopolysaccaride intravenously injection (LPS, 10mg/kg. Animals were divided into the following three groups: (1 saline + saline (n=5, (2 LPS + saline (n=5 and (3 LPS + hATSCs (2x106 (n=5. The administration of LPS caused a consistent systemic inflammatory responses, increased concentrations of the pro-inflammatory cytokines that have an important role in sepsis. Treatment of endotoxemia with hATSCs decreased the level of inflammatory cytokines both in serum and in the lung, reduced inflammatory changes in the lung, prevented apoptosis in the kidney and improved multi-organ injury. In conclusion, our data demonstrates that hATSCs regulate the immue/inflammatory responses and improve multi-organ injury and they could be attractive candidates for cell therapy to treat endotoxemia.
1. Repellent, irritant and toxic effects of 20 plant extracts on adults of the malaria vector Anopheles gambiae mosquito.
Directory of Open Access Journals (Sweden)
Emilie Deletre
Full Text Available Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged.
2. Controlled and reversible induction of differentiation and activation of adult human hepatocytes by a biphasic culture technique
Institute of Scientific and Technical Information of China (English)
Marcus K.H. Auth; Wolf-Otto Bechstein; Roman A. Blaheta; Kim A. Boost; Kerstin Leckel; Wolf-Dietrich Beecken; Tobias Engl; Dietger Jonas; Elsie Oppermann; Philip Hilgard; Bernd H. Markus
2005-01-01
AIM: Clinical application of human hepatocytes (HC) is hampered by the progressive loss of growth and differentiation in vitro. The object of the study was to evaluate the effect of a biphasic culture technique on expression and activation of growth factor receptors and differentiation of human adult HC.METHODS: Isolated HC were sequentially cultured in a hormone enriched differentiation medium (DM) containing nicotinamide, insulin, transferrin, selenium, and dexamethasone or activation medium (AM) containing hepatocyte growth factor (HGF), epidermal growth factor (EGF), andgranulocyte-macrophage colony-stimulating factor (GMCSF). Expression, distribution and activation of the HC receptors (MET and EGFR) and the pattern of characteristic cytokeratin (CK) filaments were measured by fluorometry, confocal microscopy and Western blotting.RESULTS: In the biphasic culture system, HC underwent repeated cycles of activation (characterized by expression and activation of growth factor receptors) and re-differentiation (illustrated by distribution of typical filaments CK-18 but low or absent expression of CK-19). In AM increased expression of MET and EGFR was associated with receptor translocation into the cytoplasm and induction of atypical CK-19. In DM low expression of MET and EGFR was localized on the cell membrane and CK-19 was reduced. Receptor phosphorylation required embedding of HC in collagen type Ⅰ gel.CONCLUSION: Control and reversible modulation of growth factor receptor activation of mature human HC can be accomplishedin vitro, when defined signals from the extracellular matrix and sequential growth stimuli are provided. The biphasic technique helps overcome dedifferentiation, which occurs during continuous stimulation by means of growth factors.
3. Vitamin D status in a Brazilian cohort of adolescents and young adults with perinatally acquired human immunodeficiency virus infection
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Annie Schtscherbyna
2016-02-01
Full Text Available The purpose was to determine the prevalence and related factors of vitamin D (VitD insufficiency in adolescents and young adults with perinatally acquired human immunodeficiency virus. A cohort of 65 patients (17.6 ± 2 years at the Federal University of Rio de Janeiro, Brazil, were examined for pubertal development, nutrition, serum parathormone and serum 25-hydroxyvitamin D [s25(OHD]. s25(OHD levels < 30 ng/mL (< 75 nmol/L were defined as VitD insufficiency. CD4+ T-cell counts and viral load, history of worst clinical status, immunologic status as nadir, current immunologic status, and antiretroviral (ART regimen were also evaluated as risk factors for VitD insufficiency. Mean s25(OHD was 37.7 ± 13.9 ng/mL and 29.2% had VitD insufficiency. There was no difference between VitD status and gender, age, nutritional status, clinical and immunological classification, and type of ART. Only VitD consumption showed tendency of association with s25(OHD (p = 0.064. Individuals analysed in summer/autumn season had a higher s25(OHD compared to the ones analysed in winter/spring (42.6 ± 14.9 vs. 34.0 ± 11.9, p = 0.011. Although, the frequency of VitD insufficiency did not differ statistically between the groups (summer/autumn 17.9% vs. winter/spring 37.8%, p = 0.102, we suggest to monitor s25(OHD in seropositive adolescents and young adults, especially during winter/spring months, even in sunny regions.
4. Vitamin D status in a Brazilian cohort of adolescents and young adults with perinatally acquired human immunodeficiency virus infection.
Science.gov (United States)
Schtscherbyna, Annie; Gouveia, Carla; Pinheiro, Maria Fernanda Miguens Castelar; Luiz, Ronir Raggio; Farias, Maria Lucia Fleiuss; Machado, Elizabeth Stankiewicz
2016-02-01
The purpose was to determine the prevalence and related factors of vitamin D (VitD) insufficiency in adolescents and young adults with perinatally acquired human immunodeficiency virus. A cohort of 65 patients (17.6 ± 2 years) at the Federal University of Rio de Janeiro, Brazil, were examined for pubertal development, nutrition, serum parathormone and serum 25-hydroxyvitamin D [s25(OH)D]. s25(OH)D levels ng/mL (nmol/L) were defined as VitD insufficiency. CD4+ T-cell counts and viral load, history of worst clinical status, immunologic status as nadir, current immunologic status, and antiretroviral (ART) regimen were also evaluated as risk factors for VitD insufficiency. Mean s25(OH)D was 37.7 ± 13.9 ng/mL and 29.2% had VitD insufficiency. There was no difference between VitD status and gender, age, nutritional status, clinical and immunological classification, and type of ART. Only VitD consumption showed tendency of association with s25(OH)D (p = 0.064). Individuals analysed in summer/autumn season had a higher s25(OH)D compared to the ones analysed in winter/spring (42.6 ± 14.9 vs. 34.0 ± 11.9, p = 0.011). Although, the frequency of VitD insufficiency did not differ statistically between the groups (summer/autumn 17.9% vs. winter/spring 37.8%, p = 0.102), we suggest to monitor s25(OH)D in seropositive adolescents and young adults, especially during winter/spring months, even in sunny regions. PMID:26872341
5. The reconstitution of the thymus in immunosuppressed individuals restores CD4-specific cellular and humoral immune responses.
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Plana, Montserrat; Garcia, Felipe; Darwich, Laila; Romeu, Joan; López, Anna; Cabrera, Cecilia; Massanella, Marta; Canto, Esther; Ruiz-Hernandez, Raul; Blanco, Julià; Sánchez, Marcelo; Gatell, Josep M; Clotet, Bonaventura; Ruiz, Lidia; Bofill, Margarita
2011-07-01
Infection with HIV-1 frequently results in the loss of specific cellular immune responses and an associated lack of antibodies. Recombinant growth hormone (rGH) administration reconstitutes thymic tissue and boosts the levels of peripheral T cells, so rGH therapy may be an effective adjuvant through promoting the recovery of lost cellular and T-cell-dependent humoral immune responses in immunosuppressed individuals. To test this concept, we administered rGH to a clinically defined group of HIV-1-infected subjects with defective cellular and serological immune responses to at least one of three commonly employed vaccines (hepatitis A, hepatitis B or tetanus toxoid). Of the original 278 HIV-1-infected patients entering the trial, only 20 conformed to these immunological criteria and were randomized into three groups: Group A (n = 8) receiving rGH and challenged with the same vaccine to which they were unresponsive and Groups B (n = 5) and C (n = 7) who received either rGH or vaccination alone, respectively. Of the eight subjects in Group A, five recovered CD4 cellular responses to vaccine antigen and four of these produced the corresponding antibodies. In the controls, three of the five in group B recovered cellular responses with two producing antibodies, whereas three of the seven in Group C recovered CD4 responses, with only two producing antibodies. Significantly, whereas seven of ten patients receiving rGH treatment in Group A (six patients) and B (one patient) recovered T-cell responses to HIVp24, only two of six in Group C responded similarly. In conclusion, reconstitution of the thymus in immunosuppressed adults through rGH hormone treatment restored both specific antibody and CD4 T-cell responses. PMID:21501161
6. Dominant-Negative Effects of Adult-Onset Huntingtin Mutations Alter the Division of Human Embryonic Stem Cells-Derived Neural Cells
Science.gov (United States)
Lopes, Carla; Aubert, Sophie; Bourgois-Rocha, Fany; Barnat, Monia; Rego, Ana Cristina; Déglon, Nicole
2016-01-01
Mutations of the huntingtin protein (HTT) gene underlie both adult-onset and juvenile forms of Huntington’s disease (HD). HTT modulates mitotic spindle orientation and cell fate in mouse cortical progenitors from the ventricular zone. Using human embryonic stem cells (hESC) characterized as carrying mutations associated with adult-onset disease during pre-implantation genetic diagnosis, we investigated the influence of human HTT and of an adult-onset HD mutation on mitotic spindle orientation in human neural stem cells (NSCs) derived from hESCs. The RNAi-mediated silencing of both HTT alleles in neural stem cells derived from hESCs disrupted spindle orientation and led to the mislocalization of dynein, the p150Glued subunit of dynactin and the large nuclear mitotic apparatus (NuMA) protein. We also investigated the effect of the adult-onset HD mutation on the role of HTT during spindle orientation in NSCs derived from HD-hESCs. By combining SNP-targeting allele-specific silencing and gain-of-function approaches, we showed that a 46-glutamine expansion in human HTT was sufficient for a dominant-negative effect on spindle orientation and changes in the distribution within the spindle pole and the cell cortex of dynein, p150Glued and NuMA in neural cells. Thus, neural derivatives of disease-specific human pluripotent stem cells constitute a relevant biological resource for exploring the impact of adult-onset HD mutations of the HTT gene on the division of neural progenitors, with potential applications in HD drug discovery targeting HTT-dynein-p150Glued complex interactions. PMID:26863614
7. Strategies to control human cytomegalovirus infection in adult hematopoietic stem cell transplant recipients.
Science.gov (United States)
Lilleri, Daniele; Gerna, Giuseppe
2016-09-01
Human cytomegalovirus (HCMV) represents the major viral complication after hematopoietic stem cell transplantation. HCMV infection may be controlled by the reconstituting immune system and remain subclinical or can lead to severe systemic and/or organ disease (mainly pneumonia and gastroenteritis) when immune reconstitution is delayed or impaired. In order to prevent the occurrence of HCMV disease, a prompt diagnosis of HCMV infection is mandatory. The adoption of pre-emptive therapy strategies guided by virological monitoring dramatically reduced the occurrence of HCMV disease. However, late-onset end-organ disease may occur in some patients with apparent immune reconstitution. In the near future, introduction of immunological monitoring and immunotherapies could markedly improve management of HCMV infection. PMID:27485084
8. Expression of type 2 cystatin genes CST1-CST5 in adult human tissues and the developing submandibular gland.
Science.gov (United States)
Dickinson, D P; Thiesse, M; Hicks, M J
2002-01-01
Type 2 cystatins comprise a class of cysteine peptidase inhibitor presumed to mediate protective functions at various locations, including the oral cavity. Seven cystatin genes are clustered within a 300-kb region of human 20p11.2. "Salivary" cystatins, encoded by CST1, 2, 4, and 5, are present in saliva at significant levels but have also been reported in other secretions, such as tears, suggesting that during their evolution, these genes have acquired mechanisms directing differential tissue-specific expression. However, their patterns of expression, which might also provide additional clues to their individual functions, have not been determined. Gene-specific RNase protection assays were used to examine the qualitative and quantitative distribution of expression of these seven genes within a collection of 23 adult human tissues. The CST3 gene, encoding cystatin C, was expressed at modest levels in all tissues examined. The presumptive pseudogenes CSTP1 and CSTP2 were not expressed at detectable levels in any tissue. The CST1, 2, 4, and 5 genes were expressed in differential, tissue-specific patterns. Expression of CST2 and CST5 was restricted to the submandibular and parotid glands, while CST1 and CST4 were expressed in these tissues and in the lacrimal gland. Immunohistochemistry studies localized expression to the serous-type secretory end pieces. Coexpression of CST1 and CST4 was also observed in the epithelial lining of the gallbladder and seminal vesicle. The CST1 product was detected in the tracheal glands and CST4 in the kidney and prostate. Despite their different adult patterns of expression, analysis of CST1, 2, 4, and 5 mRNA levels in infant submandibular glands demonstrated a coordinate upregulation of expression of between 3.5 and 9 months of age. The patterns of cystatin gene expression are consistent with several proposed oral functions of the salivary cystatins but also suggest they are important in other locations and that, despite their close
9. Efficacy and effectiveness of recombinant human activated protein C in severe sepsis of adults
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Greiner, Wolfgang
2007-07-01
Full Text Available Introduction: Sepsis is defined as an invasion of microorganisms and/or their toxins into the blood associated the reaction of the organism to this invasion. Severe sepsis is a major cost driver in intensive care medicine. In Germany, prevalence data was assessed in the context of the German Prevalence Study. Severe sepsis has a prevalence of 35% in German intensive care units. Research questions: The following questions were analysed: is Drotrecogin alfa (activated (DAA effective in the treatment of patients with severe sepsis and a mixed risk of death, both in all patients and in different subgroups? Is DAA effective in the treatment of patients with severe sepsis and low risk of death? Is DAA cost effective in the treatment of patients with severe sepsis compared to placebo? Methods: Only studies with adult patients are included. There are no other exclusion criteria. A systematic literature search is performed by the German Institute of Medical Documentation and Information (DIMDI. The literature search yielded as a total of 847 hits. After screening of the abstracts, 165 medical and 101 economic publications were chosen for full text appraisal. Results: Therapy with DAA appears to be cost effective in reducing 28-day-mortality in patients with severe sepsis and a high risk of death. A high risk of death is indicated by the presence of multiorgan failure (≥2 and/or an APACHE-II-Score ≥25. Therapy with DAA is not associated with a long-term reduction of mortality at later follow-up assessments. Therapy with DAA is not associated with a long-term reduction of mortality at later follow-up assessments. Therapy with DAA is cost-effective in patients with multiorgan failure and/or an APACHE II Score (≥25. In patients with a lower risk of death, DAA is not cost-effective. Costs associated with bleeding events have been rarely included in cost calculations. Discussion: DAA appears to reduce mortality in patients with severe sepsis and a high
10. Expression of Genes Related to Germ Cell Lineage and Pluripotency in Single Cells and Colonies of Human Adult Germ Stem Cells
OpenAIRE
Sabine Conrad; Hossein Azizi; Maryam Hatami; Mikael Kubista; Michael Bonin; Jörg Hennenlotter; Karl-Dietrich Sievert; Thomas Skutella
2016-01-01
The aim of this study was to elucidate the molecular status of single human adult germ stem cells (haGSCs) and haGSC colonies, which spontaneously developed from the CD49f MACS and matrix- (collagen−/laminin+ binding-) selected fraction of enriched spermatogonia. Single-cell transcriptional profiling by Fluidigm BioMark system of a long-term cultured haGSCs cluster in comparison to human embryonic stem cells (hESCs) and human fibroblasts (hFibs) revealed that haGSCs showed a characteristic ge...
11. Tai Chi Chuan Optimizes the Functional Organization of the Intrinsic Human Brain Architecture in Older Adults
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Gao-Xia eWei
2014-04-01
Full Text Available Whether Tai Chi Chuan (TCC can influence the intrinsic functional architecture of the human brain remains unclear. To examine TCC-associated changes in functional connectomes, resting-state functional magnetic resonance images were acquired from 40 older individuals including 22 experienced TCC practitioners (experts and 18 demographically matched TCC-naïve healthy controls, and their local functional homogeneities across the cortical mantle were compared. Compared to the controls, the TCC experts had significantly greater and more experience-dependent functional homogeneity in the right postcentral gyrus (PosCG and less functional homogeneity in the left anterior cingulate cortex (ACC and the right dorsal lateral prefrontal cortex (DLPFC. Increased functional homogeneity in the PosCG was correlated with TCC experience. Intriguingly, decreases in functional homogeneity (improved functional specialization in the left ACC and increases in functional homogeneity (improved functional integration in the right PosCG both predicted performance gains on attention network behavior tests. These findings provide evidence for the functional plasticity of the brain’s intrinsic architecture toward optimizing locally functional organization, with great implications for understanding the effects of TCC on cognition, behavior and health in aging population.
12. 成人教育教师人力资源管理研究%Human Resource Management of the Adult Education Teachers
Institute of Scientific and Technical Information of China (English)
2013-01-01
Adult education teachers is an important part of the adult education and human resources.Human re-sources development and management of adult education teachers in the recruitment, training, performance man-agement, development stage showed the problems, so the human resource management of adult education teachers need to be strict recruitment as a starting point,to be comprehensive training for the protection,to be based on per-formance management,to sustained continued development for the backing.% 成人教育教师是成人教育人力资源的重要组成部分。成人教育教师人力资源管理在招募、培训、绩效管理、开发等各个阶段表现出种种问题，所以，成人教育教师人力资源管理需以严格招募为起点，以全面培训为保障，以绩效管理为依据，以持续开发为后盾，建设一支专业化的成人教育教师队伍。
13. Multiple isoforms of the tumor protein p73 are expressed in the adult human telencephalon and choroid plexus and present in the cerebrospinal fluid.
Science.gov (United States)
Cabrera-Socorro, Alfredo; Pueyo Morlans, Mercedes; Suarez Sola, Maria Luisa; Gonzalez Delgado, Francisco J; Castañeyra-Perdomo, Agustin; Marin, Maria C; Meyer, Gundela
2006-04-01
p73, a homolog of the p53 tumor suppressor, codes for full-length transactivating (TA) and N-terminally truncated (DeltaN) isoforms, with pro- and anti-apoptotic activities, respectively. We examined the expression of the main p73 isoforms in adult human and mouse telencephalon and choroid plexus by immunohistochemistry on paraffin sections, and immunoblotting (IB) of tissue extracts and cerebrospinal fluid (CSF), using antibodies against different protein domains. Cortical neurons expressed TAp73 predominantly in the cytoplasm and DeltaNp73 mainly in the nucleus, with partial overlap in the cytoplasm. Highest expression was found in the hippocampus. IB showed an array of TAp73 variants in adult human cortex and hippocampus. IB of human choroid plexus and CSF using TAp73-specific antibodies revealed the presence of a approximately 90-kDa protein whose molecular weight was reduced after N-deglycosylation, suggesting that glycosylated TAp73 is exported into the CSF. In the mouse, high expression of TAp73 was also detected in the subcommissural organ (SCO), an ependymal gland absent in adult humans. TAp73 colocalized with anti-fibra-Reissner-antibody (AFRU), which is a marker of Reissner's fiber, the secreted SCO product. p73-deficient mice had generalized cortical hypoplasia and hydrocephalus; in addition, we observed a dramatic size reduction of the choroid plexus. However, the SCOs were apparently unaltered and continued to secrete Reissner's fiber. Our findings point to complex and widespread p73 activities in the maintenance of adult cortical neurons and in brain homeostasis. TAp73 in the CSF may play important roles in the maintenance of the adult ventricular wall as well as in the development of the proliferating neuroepithelium. PMID:16630058
14. Multivoxel Object Representations in Adult Human Visual Cortex Are Flexible: An Associative Learning Study.
Science.gov (United States)
Senoussi, Mehdi; Berry, Isabelle; VanRullen, Rufin; Reddy, Leila
2016-06-01
Learning associations between co-occurring events enables us to extract structure from our environment. Medial-temporal lobe structures are critical for associative learning. However, the role of the ventral visual pathway (VVP) in associative learning is not clear. Do multivoxel object representations in the VVP reflect newly formed associations? We show that VVP multivoxel representations become more similar to each other after human participants learn arbitrary new associations between pairs of unrelated objects (faces, houses, cars, chairs). Participants were scanned before and after 15 days of associative learning. To evaluate how object representations changed, a classifier was trained on discriminating two nonassociated categories (e.g., faces/houses) and tested on discriminating their paired associates (e.g., cars/chairs). Because the associations were arbitrary and counterbalanced across participants, there was initially no particular reason for this cross-classification decision to tend toward either alternative. Nonetheless, after learning, cross-classification performance increased in the VVP (but not hippocampus), on average by 3.3%, with some voxels showing increases of up to 10%. For example, a chair multivoxel representation that initially resembled neither face nor house representations was, after learning, classified as more similar to that of faces for participants who associated chairs with faces and to that of houses for participants who associated chairs with houses. Additionally, learning produced long-lasting perceptual consequences. In a behavioral priming experiment performed several months later, the change in cross-classification performance was correlated with the degree of priming. Thus, VVP multivoxel representations are not static but become more similar to each other after associative learning. PMID:26836513
15. Status of human dignity of adult patients admitted to hospitals of Tehran.
Science.gov (United States)
Borhani, Fariba; Abbaszadeh, Abbas; Moosavi, Soolmaz
2014-01-01
Maintaining dignity and respect is among patients' most fundamental rights. The importance of patient dignity, the status quo, patients' needs, and a shortage of survey studies in this area were the underlying incentives for conducting this study. This was a cross-sectional descriptive study in which data were collected through Patient Dignity Inventory (PDI). The questionnaire was completed by 280 inpatients in 2012 to determine their perspectives on their personal state of human dignity. In this study, the mean score of patients' dignity was 1.89 out of 5 (SD = 0.81). Results indicated a significant relationship between type of hospital and the distress caused by disease symptoms, peace of mind, and social support (P < 0.05). There were also relationship between type of ward and dependency (P < 0.05), type of disease and dependency (P < 0.05), gender and social support (P < 0.05), household size and peace of mind (P < 0.05). The person's satisfaction with household income showed significant relationship with symptom distress, dependency and existential distress (P < 0.05). Results showed a significant inverse correlation between age and patient dignity (P = 0.005, r = - 0.166). However, the relationship between employment status, health insurance, education level and the above factors were insignificant. Studies indicate that there is a relationship between patients' dignity and mental distress, and therefore policy makers and health services officials should establish and implement plans to maintain and enhance patients' dignity in hospitals. Educating the health team, particularly the nurses can be very effective in maintaining patients' dignity and respect. PMID:26587200
16. The SRI24 multichannel atlas of normal adult human brain structure.
Science.gov (United States)
Rohlfing, Torsten; Zahr, Natalie M; Sullivan, Edith V; Pfefferbaum, Adolf
2010-05-01
This article describes the SRI24 atlas, a new standard reference system of normal human brain anatomy, that was created using template-free population registration of high-resolution magnetic resonance images acquired at 3T in a group of 24 normal control subjects. The atlas comprises anatomical channels (T1, T2, and proton density weighted), diffusion-related channels (fractional anisotropy, mean diffusivity, longitudinal diffusivity, mean diffusion-weighted image), tissue channels (CSF probability, gray matter probability, white matter probability, tissue labels), and two cortical parcellation maps. The SRI24 atlas enables multichannel atlas-to-subject image registration. It is uniquely versatile in that it is equally suited for the two fundamentally different atlas applications: label propagation and spatial normalization. Label propagation, herein demonstrated using diffusion tensor image fiber tracking, is enabled by the increased sharpness of the SRI24 atlas compared with other available atlases. Spatial normalization, herein demonstrated using data from a young-old group comparison study, is enabled by its unbiased average population shape property. For both propagation and normalization, we also report the results of quantitative comparisons with seven other published atlases: Colin27, MNI152, ICBM452 (warp5 and air12), and LPBA40 (SPM5, FLIRT, AIR). Our results suggest that the SRI24 atlas, although based on 3T MR data, allows equally accurate spatial normalization of data acquired at 1.5T as the comparison atlases, all of which are based on 1.5T data. Furthermore, the SRI24 atlas is as suitable for label propagation as the comparison atlases and detailed enough to allow delineation of anatomical structures for this purpose directly in the atlas. PMID:20017133
17. Repopulation of the atrophied thymus in diabetic rats by insulin-like growth factor I
International Nuclear Information System (INIS)
Atrophy of the thymus is one of the consequences of severe insulin deficiency. The authors describe here that the weight and the architecture of the thymus of diabetic rats is restored towards normal not only by insulin but also by insulin-like growth factor I (IGF-I) treatment. In contrast to insulin, this effect of IGF-I occurs despite persisting hyperglycemia and adrenal hyperplasia. They also investigated the in vivo effect of IGF-I on replication and differentiation of thymocytes from streptozotocin-induced diabetic rats. Thymocytes from diabetic rats incorporated less [3H]thymidine than did thymocytes from healthy rats. Insulin, as well as IGF-I treatment of diabetic rats increased [3H]thymidine incorporation by thymocytes. Flow cytometry of thymocytes labeled with monoclonal antibodies revealed a decreased expression of the Thy-1 antigen in diabetic rats compared with control rats. In addition, a major deficiency of thymocytes expressing simultaneously the W3/25 and the Ox8 antigens was observed. These changes were restored towards normal by insulin as well as by IGF-I treatment. The antibody response to a T cell-dependent antigen (bovine serum albumin) was comparable in normal and diabetic rats. They conclude that IGF-I has important effects on the thymocyte number and the presence of CD4+/CD8+ immature cells in the thymus of diabetic rats despite persisting hyperglycemia. However, helper T-cell function for antibody production appears to be preserved even in the severely diabetic state
18. Gene expression profiling and secretome analysis differentiate adult-derived human liver stem/progenitor cells and human hepatic stellate cells.
Directory of Open Access Journals (Sweden)
Silvia Berardis
Full Text Available Adult-derived human liver stem/progenitor cells (ADHLSC are obtained after primary culture of the liver parenchymal fraction. The cells are of fibroblastic morphology and exhibit a hepato-mesenchymal phenotype. Hepatic stellate cells (HSC derived from the liver non-parenchymal fraction, present a comparable morphology as ADHLSC. Because both ADHLSC and HSC are described as liver stem/progenitor cells, we strived to extensively compare both cell populations at different levels and to propose tools demonstrating their singularity. ADHLSC and HSC were isolated from the liver of four different donors, expanded in vitro and followed from passage 5 until passage 11. Cell characterization was performed using immunocytochemistry, western blotting, flow cytometry, and gene microarray analyses. The secretion profile of the cells was evaluated using Elisa and multiplex Luminex assays. Both cell types expressed α-smooth muscle actin, vimentin, fibronectin, CD73 and CD90 in accordance with their mesenchymal origin. Microarray analysis revealed significant differences in gene expression profiles. HSC present high expression levels of neuronal markers as well as cytokeratins. Such differences were confirmed using immunocytochemistry and western blotting assays. Furthermore, both cell types displayed distinct secretion profiles as ADHLSC highly secreted cytokines of therapeutic and immuno-modulatory importance, like HGF, interferon-γ and IL-10. Our study demonstrates that ADHLSC and HSC are distinct liver fibroblastic cell populations exhibiting significant different expression and secretion profiles.
19. Early-life disease exposure and associations with adult survival, cause of death, and reproductive success in preindustrial humans.
Science.gov (United States)
Hayward, Adam D; Rigby, Francesca L; Lummaa, Virpi
2016-08-01
A leading hypothesis proposes that increased human life span since 1850 has resulted from decreased exposure to childhood infections, which has reduced chronic inflammation and later-life mortality rates, particularly from cardiovascular disease, stroke, and cancer. Early-life cohort mortality rate often predicts later-life survival in humans, but such associations could arise from factors other than disease exposure. Additionally, the impact of early-life disease exposure on reproduction remains unknown, and thus previous work ignores a major component of fitness through which selection acts upon life-history strategy. We collected data from seven 18th- and 19th-century Finnish populations experiencing naturally varying mortality and fertility levels. We quantified early-life disease exposure as the detrended child mortality rate from infectious diseases during an individual's first 5 y, controlling for important social factors. We found no support for an association between early-life disease exposure and all-cause mortality risk after age 15 or 50. We also found no link between early-life disease exposure and probability of death specifically from cardiovascular disease, stroke, or cancer. Independent of survival, there was no evidence to support associations between early-life disease exposure and any of several aspects of reproductive performance, including lifetime reproductive success and age at first birth, in either males or females. Our results do not support the prevailing assertion that exposure to infectious diseases in early life has long-lasting associations with later-life all-cause mortality risk or mortality putatively linked to chronic inflammation. Variation in adulthood conditions could therefore be the most likely source of recent increases in adult life span. PMID:27457937
20. Biological character of human adipose-derived adult stem cells and influence of donor age on cell replication in culture
Institute of Scientific and Technical Information of China (English)
2007-01-01
1. A comparative study of the structural organization of spheres derived from the adult human subventricular zone and glioblastoma biopsies
International Nuclear Information System (INIS)
Sphere forming assays have been useful to enrich for stem like cells in a range of tumors. The robustness of this system contrasts the difficulties in defining a stem cell population based on cell surface markers. We have undertaken a study to describe the cellular and organizational composition of tumorspheres, directly comparing these to neurospheres derived from the adult human subventricular zone (SVZ). Primary cell cultures from brain tumors were found to contain variable fractions of cells positive for tumor stem cell markers (CD133 (2-93%)/SSEA1 (3-15%)/CXCR4 (1-72%)). All cultures produced tumors upon xenografting. Tumorspheres contained a heterogeneous population of cells, but were structurally organized with stem cell markers present at the core of spheres, with markers of more mature glial progenitors and astrocytes at more peripheral location. Ultrastructural studies showed that tumorspheres contained a higher fraction of electron dense cells in the core than the periphery (36% and 19%, respectively). Neurospheres also contained a heterogeneous cell population, but did not have an organization similar to tumorspheres. Although tumorspheres clearly display irregular and neoplastic cells, they establish an organized structure with an outward gradient of differentiation. We suggest that this organization is central in maintaining the tumor stem cell pool.
2. A comparative study of the structural organization of spheres derived from the adult human subventricular zone and glioblastoma biopsies
Energy Technology Data Exchange (ETDEWEB)
Vik-Mo, Einar Osland, E-mail: [email protected] [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Department of Neurosurgery, Oslo University Hospital, Oslo (Norway); Sandberg, Cecilie [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Joel, Mrinal [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Department of Physiology, Institute of Basic Medical Sciences, University of Oslo (Norway); Stangeland, Biljana [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Watanabe, Yasuhiro [Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago 683-8504 (Japan); Mackay-Sim, Alan [National Centre for Adult Stem Cell Research, Eskitis Institute for Cell and Molecular Therapies, Griffith University, Brisbane, QLD 4111 (Australia); Moe, Morten Carstens [Center for Eye Research, Department of Ophthalmology, Oslo University Hospital, Oslo (Norway); Murrell, Wayne [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Langmoen, Iver Arne [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Department of Neurosurgery, Oslo University Hospital, Oslo (Norway)
2011-04-15
Sphere forming assays have been useful to enrich for stem like cells in a range of tumors. The robustness of this system contrasts the difficulties in defining a stem cell population based on cell surface markers. We have undertaken a study to describe the cellular and organizational composition of tumorspheres, directly comparing these to neurospheres derived from the adult human subventricular zone (SVZ). Primary cell cultures from brain tumors were found to contain variable fractions of cells positive for tumor stem cell markers (CD133 (2-93%)/SSEA1 (3-15%)/CXCR4 (1-72%)). All cultures produced tumors upon xenografting. Tumorspheres contained a heterogeneous population of cells, but were structurally organized with stem cell markers present at the core of spheres, with markers of more mature glial progenitors and astrocytes at more peripheral location. Ultrastructural studies showed that tumorspheres contained a higher fraction of electron dense cells in the core than the periphery (36% and 19%, respectively). Neurospheres also contained a heterogeneous cell population, but did not have an organization similar to tumorspheres. Although tumorspheres clearly display irregular and neoplastic cells, they establish an organized structure with an outward gradient of differentiation. We suggest that this organization is central in maintaining the tumor stem cell pool.
3. Hexamminecobalt(III)-induced condensation of calf thymus DNA: circular dichroism and hydration measurements
OpenAIRE
Kankia, Besik I.; Buckin, Vitaly; Bloomfield, Victor A
2001-01-01
The interaction of hexamminecobalt(III), Co(NH3)63+, with 160 and 3000–8000 bp length calf thymus DNA has been investigated by circular dichroism, acoustic and densimetric techniques. The acoustic titration curves of 160 bp DNA revealed three stages of interaction: (i) Co(NH3)63+ binding up to the molar ratio [Co(NH3)63+]/[P] = 0.25, prior to DNA condensation; (ii) a condensation process between [Co(NH3)63+]/[P] = 0.25 and 0.30; and (iii) precipitation after [Co(NH...
4. Successful Resection of Giant Mediastinal Lipofibroadenoma of the Thymus by Video-Assisted Thoracoscopic Surgery.
Science.gov (United States)
Makdisi, George; Roden, Anja C; Shen, K Robert
2015-08-01
We report the case of a 20-year-old man who presented with a large heterogeneous mass incidentally found on a chest roentgenogram performed in the context of acute onset of fever and cough. A chest computed tomography scan showed a large heterogenous mass in the anterior mediastinum. The patient underwent surgical resection by a right video-assisted thoracoscopic approach. The resected mass was completely encapsulated and was histologically determined to be a lipofibroadenoma. Complete resection is curative. This is the sixth reported case of lipofibroadenoma of the thymus in the English literature and the first reported case of video-assisted thoracoscopic resection of a lipofibroadenoma. PMID:26234840
5. Chemical composition of Thymus vulgaris L. (thyme essential oil from the Rio de Janeiro State (Brazil
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ALEXANDRE PORTE
2008-03-01
Full Text Available The essential oil from fresh leaves of Thymus vulgaris L. from Rio de Janeiro State, Brazil, was isolated by hydrodistillation and analyzed through a combination of GC and GC/MS. Compounds representing 95.1 % of the oil were identified. Thirty-nine constituents were detected, of which twenty-eight were identified according to their chromatographic retention indices and mass spectra. The major constituents of the oil were thymol (44.7 %, p-cymene (18.6 % and g-terpinene (16.5 %.
6. Changes in Mouse Thymus and Spleen after Return from the STS-135 Mission in Space
Science.gov (United States)
Gridley, Daila S.; Mao, Xiao Wen; Stodieck, Louis S.; Ferguson, Virginia L.; Bateman, Ted A.; Moldovan, Maria; Cunningham, Christopher E.; Jones, Tamako A.; Slater, Jerry M.; Pecaut, Michael J.
2013-01-01
Our previous results with flight (FLT) mice showed abnormalities in thymuses and spleens that have potential to compromise immune defense mechanisms. In this study, the organs were further evaluated in C57BL/6 mice after Space Shuttle Atlantis returned from a 13-day mission. Thymuses and spleens were harvested from FLT mice and ground controls housed in similar animal enclosure modules (AEM). Organ and body mass, DNA fragmentation and expression of genes related to T cells and cancer were determined. Although significance was not obtained for thymus mass, DNA fragmentation was greater in the FLT group (P<0.01). Spleen mass alone and relative to body mass was significantly decreased in FLT mice (P<0.05). In FLT thymuses, 6/84 T cell-related genes were affected versus the AEM control group (P<0.05; up: IL10, Il18bp, Il18r1, Spp1; down: Ccl7, IL6); 15/84 cancer-related genes had altered expression (P<0.05; up: Casp8, FGFR2, Figf, Hgf, IGF1, Itga4, Ncam1, Pdgfa, Pik3r1, Serpinb2, Sykb; down: Cdc25a, E2F1, Mmp9, Myc). In the spleen, 8/84 cancer-related genes were affected in FLT mice compared to AEM controls (P<0.05; up: Cdkn2a; down: Birc5, Casp8, Ctnnb1, Map2k1, Mdm2, NFkB1, Pdgfa). Pathway analysis (apoptosis signaling and checkpoint regulation) was used to map relationships among the cancer–related genes. The results showed that a relatively short mission in space had a significant impact on both organs. The findings also indicate that immune system aberrations due to stressors associated with space travel should be included when estimating risk for pathologies such as cancer and infection and in designing appropriate countermeasures. Although this was the historic last flight of NASA’s Space Shuttle Program, exploration of space will undoubtedly continue. PMID:24069384
7. Rheology of semi-dilute solutions of calf-thymus DNA
2002-04-01
We study the rheology of semi-dilute solutions of the sodium salt of calf-thymus DNA in the linear and nonlinear regimes. The frequency response data can be fitted very well to the hybrid model with two dominant relaxation times 0 and 1. The ratio (0/1)∼ 5 is seen to be fairly constant on changing the temperature from 20 to 30°C. The shear rate dependence of viscosity can be fitted to the Carreau model.
8. Study on the Interaction between Isatin-β-Thiosemicarbazone and Calf Thymus DNA by Spectroscopic Techniques
OpenAIRE
Pakravan, Parvaneh; Masoudian, Shahla
2015-01-01
The interaction between isatin-β-thiosemicarbazone (IBT) and calf thymus DNA (CT-DNA) was investigated in physiological buffer (pH 7.4) using Neutral Red (NR) dye as a spectral probe by UV–Vis absorption and fluorescence spectroscopy, as well as viscosity measurements. The IBT is stabilized by intercalation in the DNA (K [IBT –DNA] = 1.03×105 M−1), and displaces the NR dye from the NR–DNA complex. The binding constants Kf and number of binding sites (n≈1) of IBT with DNA were obtained by fluor...
9. Cytologic Findings of Thyroid Carcinoma Showing Thymus-like Differentiation: A Case Report
OpenAIRE
Chang, Sunhee; Joo, Mee; Kim, Hanseong
2012-01-01
Carcinoma showing thymus-like differentiation (CASTLE) is a rare carcinoma of the thyroid or adjacent soft tissue of the neck with a histologic resemblance to thymic epithelial tumors. Although the fine-needle aspiration (FNA) plays a central role in the initial evaluation of thyroid nodules, few reports about the cytologic findings of CASTLE have been found according to a review of literatures. We report cytologic findings of a case of CASTLE. A 34-year-old woman presented with a 2-month his...
10. An occasional diagnosis of myasthenia gravis - a focus on thymus during cardiac surgery: a case report
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Dainese Luca
2009-10-01
Full Text Available Abstract Background Myasthenia gravis, an uncommon autoimmune syndrome, is commonly associated with thymus abnormalities. Thymomatous myasthenia gravis is considered to have worst prognosis and thymectomy can reverse symptoms if precociously performed. Case report We describe a case of a patient who underwent mitral valve repair and was found to have an occasional thymomatous mass during the surgery. A total thymectomy was performed concomitantly to the mitral valve repair. Conclusion The diagnosis of thymomatous myasthenia gravis was confirmed postoperatively. Following the surgery this patient was strictly monitored and at 1-year follow-up a complete stable remission had been successfully achieved.
11. Thymus capitatus essential oil reducing citrus fruit decay
OpenAIRE
Arras, Giovanni; Piga, Antonio
1995-01-01
Thymus capitatus essential oil was employed as vapour in postharverst to reduce Botrys cinerea grey mould in mandarin fruits. The latter were sprayerd with 105 spores/ml suspension, placed in 15-litre desiccators at 25°C and fumigated under vacuum conditions at varying concentrations of thyme oil. The desiccators were kept for 24 h and then the fruit rinse water was plated in Petri dishes to test spore viability. The results showed that the untreated control rinse water exhibited a high rate ...
12. Morphology, distribution, and histochemistry of trichomes of Thymus lykae Degen & Jav. (Lamiaceae
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Marin Marija
2008-01-01
Full Text Available Micromorphology, distribution, and histochemistry of the trichomes of Thymus lykae were studied using scanning electron microscopy (SEMand confocal laser scanning electron microscopy (CLSM. The leaves, stem, and calyx bear numerous glandular and non-glandular trichomes. Two types of glandular trichomes are identified - peltate and capitate. Results of histochemical tests showed positive reactions to polysaccharides, proteins, and lipids. Yellow autofluorescence of secreted material was noticed in peltate and capitate trichomes. Strong reddish-yellow autofluorescence of the lipophilic and hydrophilic secreted material was observed with CLSM.
13. New facets of keratin K77: interspecies variations of expression and different intracellular location in embryonic and adult skin of humans and mice.
Science.gov (United States)
Langbein, Lutz; Reichelt, Julia; Eckhart, Leopold; Praetzel-Wunder, Silke; Kittstein, Walter; Gassler, Nikolaus; Schweizer, Juergen
2013-12-01
The differential expression of keratins is central to the formation of various epithelia and their appendages. Structurally, the type II keratin K77 is closely related to K1, the prototypical type II keratin of the suprabasal epidermis. Here, we perform a developmental study on K77 expression in human and murine skin. In both species, K77 is expressed in the suprabasal fetal epidermis. While K77 appears after K1 in the human epidermis, the opposite is true for the murine tissue. This species-specific pattern of expression is also found in conventional and organotypic cultures of human and murine keratinocytes. Ultrastructure investigation shows that, in contrast to K77 intermediate filaments of mice, those of the human ortholog are not attached to desmosomes. After birth, K77 disappears without deleterious consequences from human epidermis while it is maintained in the adult mouse epidermis, where its presence has so far gone unnoticed. After targeted Krt1 gene deletion in mice, K77 is normally expressed but fails to functionally replace K1. Besides the epidermis, both human and mouse K77 are present in luminal duct cells of eccrine sweat glands. The demonstration of a K77 ortholog in platypus but not in non-mammalian vertebrates identifies K77 as an evolutionarily ancient component of the mammalian integument that has evolved different patterns of intracellular distribution and adult tissue expression in primates. PMID:24057875
14. Radioimmunodetection of human leukemia with anti-interleukin-2 receptor antibody in severe combined immunodeficiency mice
International Nuclear Information System (INIS)
Anti-Tac monoclonal antibody recognizes human interleukin-2 receptor, which is overexpressed in leukemic cells of most adult T-cell leukemia (ATL) patients. To examine the potency of anti-Tac for targeting of ATL, biodistributions of intravenously administered 125I- and 111In-labeled anti-Tac were examined in severe combined immunodeficiency (SCID) mice inoculated with ATL cells. Significant amounts of radiolabeled anti-Tac were found in the spleen and thymus. The trafficking of ATL cells in SCID mice was detected using 111In-oxine-labeled ATL cells. These results were coincident with the histologically confirmed infiltration of ATL cells. The radiolabeled anti-Tac seemed potent for targeting of ATL
15. Identification and analysis of a novel protein-tyrosine kinase from bovine thymus
Energy Technology Data Exchange (ETDEWEB)
Zioncheck, T.F.; Harrison, M.L.; Geahlen, R.L.
1986-05-01
A cytosolic protein-tyrosine kinase has been identified and purified to near homogeneity from calf thymus by using the phosphorylation of the tyrosine-containing peptide angiotensin I as an assay. Specific peptide phosphorylating activity was enhanced by carrying out the assay at high ionic strength (2M NaCl). The inclusion of NaCl at this concentration acts to stimulate endogenous protein-tyrosine kinase activity while simultaneously inhibiting other endogenous kinases. The purification procedure involved extraction of the enzyme from calf-thymus and sequential chromatography on columns of DEAE-cellulose, heparin-agarose, casein-sepharose, butylagarose, and Sephadex G-75. Analysis of the most highly purified preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single Coomassie blue-stained band of 41 KDa. This molecular weight was consistent with results obtained from gel filtration, indicating that the enzyme exists as a monomer. The enzyme has also been found to catalyze an autophosphorylation reaction. Incubation of the enzyme with Mn/sup 2 +/ and (..gamma..-/sup 32/P)ATP led to its modification on a tyrosine residue. Phosphopeptide mapping experiments indicated that the 41 KDa kinase was distinct from p56, the major membrane-associated protein-tyrosine kinase in T lymphocytes.
16. Frequency and polymorphism of Hassall’s corpuscles in normal thymus of nutria (Myocastor coypus
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Viorel Miclăuş
2009-04-01
Full Text Available Thymus from three clinically healthy 12-month-old age nutria were collected and histologically processed. Microscopic examination showed that the thymus contains numerous Hassall’s corpuscles in various stages of development, from very small (10-15 μm, composed of 1-2 degenerate reticuloepithelial cells, to very large corpuscles (sometimes exceeding 500 μm. In nutria, the genesis of Hassall’s corpuscles is more rapid than in most mammals. The corpuscles showed extended polymorphism, from round corpuscles to very particular forms, even odd, in some cases. The degenerated reticulo-epithelial cells represent the starting point in Hassall’s corpuscles formation. They ensure the growth of Hassall’s corpuscles and their adhesion to the reticulo-epithelial network, as well as the binding of two or more adjacent corpuscles. In a more advanced stage, increase in size of the joint corpuscles reduce the separating spaces up to absence, resulting corpuscles that appear like entities of 5-10 joint corpuscles, in different stages of organization. The fast genesis of Hassall’s corpuscles and inter corpuscular binding by means of degenerate reticulo-epithelial cells causes the particular polymorphism of these corpuscles with nutria.
17. Studies on Chemical Composition, Antimicrobial and Antioxidant Activities of Five Thymus vulgaris L. Essential Oils
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Emilia Mancini
2015-07-01
Full Text Available This study is aimed at assessing the essential oil composition, total phenolic content, antimicrobial and antioxidant activities of Thymus vulgaris collected in five different area of the Campania Region, Southern Italy. The chemical composition of the essential oils was studied by GC-flame ionization detector (FID and GC/MS; the biological activities were evaluated through determination of MIC and minimum bactericidal concentration (MBC and evaluation of antioxidant activity. In total, 134 compounds were identified. The oils were mainly composed of phenolic compounds, and all oils belonged to the chemotype thymol. The antimicrobial activity of the five oils was assayed against ten bacterial strains. The oils showed different inhibitory activity against some Gram-positive pathogens. The total phenol content in the essential oils ranged from 77.6–165.1 mg gallic acid equivalents (GAE/g. The results reported here may help to shed light on the complex chemotaxonomy of the genus Thymus. These oils could be used in many fields as natural preservatives of food and as nutraceuticals.
18. Cryopreservation of Thymus cariensis and T. vulgaris shoot tips: comparison of three vitrification-based methods.
Science.gov (United States)
Ozudogru, E A; Kaya, E
2012-01-01
Thymus is an important genus of the Lamiaceae family, comprising more than 400 perennial aromatic thyme species, which are used extensively for medicinal and culinary purposes. The present study focused on the development of cryopreservation procedures for Thymus vulgaris and T. cariensis, the latter being an endemic and endangered species of Turkey. For cryopreservation of T. vulgaris shoot tips, PVS2-based one-step freezing methods, i.e., PVS2 vitrification, encapsulation-vitrification and droplet-vitrification, were compared. Cold hardening and sucrose preculture were also optimized before the cryopreservation trials. For T. cariensis, a droplet-vitrification method was applied to cold-hardened shoot tips, and after sucrose preculture. In all the methods tested, PVS2 was applied for up to 120 min. The best T. vulgaris cryopreservation was achieved with a droplet-vitrification method, that involved 2-weeks cold hardening of shoot cultures, 48 h preculture of shoot tips on MS medium supplemented with 0.25 M sucrose, and a 90 min PVS2 treatment in droplets. After direct immersion in LN, thawing and plating, 80% of shoot-tips recovered. Post-thaw recovery was significantly lower when the same procedure was applied to T. cariensis shoot tips; however also here 90 min PVS2 treatment produced the highest survival (25 percent) and recovery (25 percent) levels. PMID:23224369
19. Increased generation of Foxp3(+) regulatory T cells by manipulating antigen presentation in the thymus.
Science.gov (United States)
Lin, Jiqiang; Yang, Lu; Silva, Hernandez Moura; Trzeciak, Alissa; Choi, Yongwon; Schwab, Susan R; Dustin, Michael L; Lafaille, Juan J
2016-01-01
Regulatory T-cell (Treg) selection in the thymus is essential to prevent autoimmune diseases. Although important rules for Treg selection have been established, there is controversy regarding the degree of self-reactivity displayed by T-cell receptors expressed by Treg cells. In this study we have developed a model of autoimmune skin inflammation, to determine key parameters in the generation of skin-reactive Treg cells in the thymus (tTreg). tTreg development is predominantly AIRE dependent, with an AIRE-independent component. Without the knowledge of antigen recognized by skin-reactive Treg cells, we are able to enhance skin-specific tTreg cell generation using three approaches. First, we increase medullary thymic epithelial cells by using mice lacking osteoprotegerin or by adding TRANCE (RANKL, Tnfsf11). Second, we inject intrathymically peripheral dendritic cells from skin-draining sites. Finally, we inject skin tissue lysates intrathymically. These findings have implications for enhancing the generation of organ-specific Treg cells in autoimmune diseases. PMID:26923114
20. Identification and analysis of a novel protein-tyrosine kinase from bovine thymus
International Nuclear Information System (INIS)
A cytosolic protein-tyrosine kinase has been identified and purified to near homogeneity from calf thymus by using the phosphorylation of the tyrosine-containing peptide angiotensin I as an assay. Specific peptide phosphorylating activity was enhanced by carrying out the assay at high ionic strength (2M NaCl). The inclusion of NaCl at this concentration acts to stimulate endogenous protein-tyrosine kinase activity while simultaneously inhibiting other endogenous kinases. The purification procedure involved extraction of the enzyme from calf-thymus and sequential chromatography on columns of DEAE-cellulose, heparin-agarose, casein-sepharose, butylagarose, and Sephadex G-75. Analysis of the most highly purified preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single Coomassie blue-stained band of 41 KDa. This molecular weight was consistent with results obtained from gel filtration, indicating that the enzyme exists as a monomer. The enzyme has also been found to catalyze an autophosphorylation reaction. Incubation of the enzyme with Mn2+ and [γ-32P]ATP led to its modification on a tyrosine residue. Phosphopeptide mapping experiments indicated that the 41 KDa kinase was distinct from p56, the major membrane-associated protein-tyrosine kinase in T lymphocytes | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.528529167175293, "perplexity": 19737.326944962846}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560284376.37/warc/CC-MAIN-20170116095124-00050-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://www.palmsens.com/knowledgebase-article/potentiostat/the-equations-behind-the-potentiostat/ | # The equations behind the potentiostat
This article explains the working of a potentiostat more in depth, using Faraday’s law and the Nernst equation. For the basics of the potentiostat, please read the potentiostat article.
A potentiostat controls the potential of the working electrode and measures the current flowing through it. Why not just two electrodes? One of the reasons is that we cannot measure the potential of the working electrode against a fixed point when we just have two electrodes.
Imagine a two-electrode system that consists of the already mentioned working electrode and the electrode, which potential should be our fixed reference point, the reference electrode.
We apply a certain potential between these electrodes and an electrochemical reaction happens at the working electrode, but since the circuit needs to be closed and current needs to flow, a reaction that is inverse to the reaction at the working electrode must occur, that is if oxidation occurs at the working electrode, a reduction must take place at the reference electrode.
If a current flows at a constant potential, an electrochemical reaction must happen according to Faraday’s law:
This equation says that the charge Q flowing through an electrode is proportional to the amount n of a species that took or gave z electrons at the electrode. F is the Faraday constant and represents the charge of 1 mol electrons. The current I is the charge Q per time t flowing through the electrode:
The equations 3.1 and 3.2 combination shows that the current I flowing is connected to the reaction happening at the electrode via the amount n:
## Nernst equation
Imagine now that the current is flowing at the reference electrode. At this electrode a species’ amount of n is converted. This conversion leads to a change of the surface or the concentration of the solution surrounding the electrode. The Nernst equation shows a clear correlation between the potential E of an electrode and its surrounding:
E0 is the standard potential of the redox couple Red and Ox. R is the gas constant and T the temperature. The activity of the oxidized and reduced form of the species aOx and aRed in the surrounding solution is not always easy to predict. This often leads to a simplification of the equation:
The two activity coefficients fOx and fRed are included in the resulting potential E0’, which is called the formal potential. Since it contains parameters that depend on the environment, such as temperature and activity coefficients, E0’ cannot be listed but needs to be determined for each experiment, if necessary. Most experiments in analytical chemistry are performed at room temperature (295 K). This makes another simplification possible. Out of convenience also the ln will be transferred to the log.
For practical application equation 3.6 is the most used form of the Nernst equation. For many applications one can assume that E0 is roughly the same as E0’, because both of the activity coefficients are close to one.
In this form (equation 3.6) the correlation between the surrounding of an electrode and its potential is visible more easily.
As mentioned before all the simplifications at equation 3.4 were performed: The change of the solution surrounding the reference electrode, due to a flowing current, leads to a change of the potential that is supposed to be our fixed reference point. But we cannot limit the current flow through the reference electrode (RE), because all limitations should be caused by the process that we want to investigate, that is the process at the working electrode (WE).
## Using a third electrode
To create a fixed reference point, we use a third electrode.
At this counter electrode (CE), also known as the auxiliary electrode, the counter-reaction to the working electrode’s reactions takes place. The current is flowing between the working and the counter electrode. The potential is controlled between the working and reference electrode (see Figure 3.1).
The potential between the counter and reference electrode is adjusted in such a way that the current flowing through the working electrode at a certain potential between working and reference electrode is satisfied. There are limits for the potential a potentiostat can apply between RE and WE (DC potential range) and CE and WE (compliance voltage).
Since you control the potential between RE and WE it is easy to stay within the limits of the DC potential range. The CE has to be bigger than the WE, because the compliance voltage cannot be controlled by the user. A bigger surface at the same potential leads to a higher current and the CE should provide enough current without running into the compliance voltage.
A rule of thumb suggests that the CE should be 100 times bigger than the WE. For many experiments this may not be necessary, but for a good practice you should ensure that the CE is big enough so that it does not limit the current flowing at the WE.
Usually the distance between CE and WE is big enough so the reactions of the two electrodes do not influence each other, and the counter-reaction can be ignored, but sometimes, in small volumes for example, it can be helpful to know which reaction happens at the counter electrode.
The potential is applied between reference and working electrode, while the current flows through working and counter electrode. This way a constant reference point for the potential is maintained. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.882846474647522, "perplexity": 548.8727610818358}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296948932.75/warc/CC-MAIN-20230329023546-20230329053546-00238.warc.gz"} |
https://math.stackexchange.com/questions/3013566/buffons-needle-expected-number-of-intersections-pmf-when-l-d | # Buffon's needle: expected number of intersections & pmf when $l > d$
Earlier results have shown that when $$l < d$$, the expected number of crossings of a needle of length $$l$$ with vertical lines spaced $$d$$ apart is $$\frac{2l}{\pi d}$$, which is also the expression for the probability that a needle intersects a line. I'm looking for an intuitive explanation for why that is the case (is that even the case...?) when the needle is longer ie. $$l > d$$ (consider $$l = 3, d = 1$$ for example).
This does not match the expression for the probability that a needle intersects a line when $$l > d$$; rather, it matches the expression for the probability that a needle intersects a line when $$l < d$$. Is this just because the possible numbers of crossings are no longer restricted to $$0$$ and $$1$$ (ie. the $$0$$ term cancels out when computing the expected value)?
And, how would one find the PMF of the number of crossings when $$l > d$$ (for a simpler case such as $$l = 3, d = 1$$)? The possible values for the numbers of crossings are $$0, 1, 2, 3, 4$$ if I'm not mistaken. But I don't know where to go from there.
edit: still looking for the PMF!
• Possibly helpful: cs.umb.edu/~eb/piday/whypi.pdf – Ethan Bolker Nov 25 '18 at 23:38
• @EthanBolker I guess so! Still only deals with the situation when $l = d$. was really hoping for some hard-hitting intuition when $l > d$, but maybe it's just not intuitive and that's all there is to it. – 0k33 Nov 25 '18 at 23:44
• I think that discussion covers the case you are interested in since it explains (or at least asserts) that the crossing number in fact depends on the ratio of $d$ to $l$. – Ethan Bolker Nov 26 '18 at 0:02
• When $l \lt d$, the probability of crossing is equal to the expected number of crossings for precisely the reason you give: the number of crossings can only be $0$ or $1$. When $l\gt d$ then the $\frac{2l}{\pi d}$ gives the number of expected crossings but not the (smaller) probability of of at least one crossing - the expression is obviously not the probability when $\frac{l}{d}l \gt \frac{\pi}{2}$ since the expression will be greater than $1$ – Henry Nov 26 '18 at 0:36
• @Henry Yes, of course. – Ethan Bolker Nov 26 '18 at 0:42
It is clear that we can rescale the problem and take, wlog, $$d=1$$ and $$l/d=r$$.
Therefore we can take the lines to be the vertical lines at $$x \in \mathbb Z$$.
Consider the needle placed with one end at $$(s,0)$$ and forming an angle $$\alpha$$ wrt the $$x$$ axis: we can sketch the following scheme
Considering the simmetry of the problem, we can limit to the I and II quadrants.
Also, the variable $$s$$ will be limited to the range $$\left[ {0,1} \right)$$.
However, there is a symmetry around $$s=1/2$$, so we will reduce our analysis to $$0 \le s < 1/2$$, considering $$s$$ and $$1-s$$ to be equivalent.
The circle with center in $$(s,0)$$ and radius $$r$$ encompasses the abscissas $$s-r \le x \le s+r$$.
The set of lines that the needle can cross are those given by $$x = n\quad \left| {\;\left\lceil {s - r} \right\rceil \le n \le \left\lfloor {s + r} \right\rfloor } \right.$$
It is convenient to extend the values of $$n$$ by two additional elements at the extremes, and define a set of boundary values for $$x$$ and for the angle $$\alpha$$ defined as follows $$\left\{ \matrix{ N = \left\{ {n\quad \left| {\;\left\lceil {s - r} \right\rceil - 1 \le n \le \left\lfloor {s + r} \right\rfloor + 1} \right.} \right\} \hfill \cr X = \left\{ {x(n)} \right\} = \left\{ {\left( {s - r} \right),\;\left\lceil {s - r} \right\rceil ,\;\left\lceil {s - r} \right\rceil + 1,\; \cdots ,\;0, \;1, \cdots ,\left\lfloor {s + r} \right\rfloor ,\left( {s + r} \right)} \right\} \hfill \cr A = \left\{ {\alpha (n) = \arccos \left( {{{x(n) - s} \over r}} \right)} \right\} = \left\{ {\pi ,\;\arccos \left( {{{\left\lceil {s - r} \right\rceil - s} \over r}} \right),\; \cdots ,\; \arccos \left( {{{\left\lfloor {s + r} \right\rfloor - s} \over r}} \right),\;0} \right\} \hfill \cr} \right.$$ where the set $$A$$ is in non-increasing order, contrary to the others.
In this way, the arc corresponding to $$q$$ intersections will be individuated by the values of $$x$$ such that $$\bbox[lightyellow] { x \in \left( {\left( { - q, - q + 1} \right] \cup \left[ {q,q + 1} \right)} \right) \cap \left[ {s - r,\;s + r} \right] } \tag{1}$$ so that we have in general two arcs, except
- at $$q=0$$ in which case we have just one range;
- (possibly) at the extremes , where the range could be void or of null measure, depending on the values of $$r$$ and $$s$$.
In an another perspective, by the above we are assigning a value $$q$$ to the intervals delimited by the points in $$X$$,
and correspondingly to the arcs delimited by the angles in $$A$$.
Thus we are constructing a measure of the angle $$Ang(q,s;r)$$ as the sum of one or two angles.
The position $$s$$ and the angle $$\alpha$$ are supposed independent and uniformly distributed, thus the
probability of having $$N$$ intersections
is given by \bbox[lightyellow] { \eqalign{ & dP(q,\,s;\;r) = dP(q,\,1 - s;\;r)\quad \left| \matrix{ \;0 \le s < 1/2 \hfill \cr \;0 < r \hfill \cr \;0 \le q \in Z \hfill \cr} \right. = \cr & = {1 \over \pi }{{ds} \over {1/2}}\left( {\alpha \left( { - q} \right) - \alpha \left( { - q + 1} \right) + \alpha \left( q \right) - \alpha \left( {q + 1} \right)} \right) \cr} } \tag{2}
After that, since \eqalign{ & \int {\arccos \left( {{{n - s} \over r}} \right)ds} = - r\int {\arccos \left( {{{n - s} \over r}} \right)d\left( {{{n - s} \over r}} \right)} = \cr & = r\left( {\sqrt {1 - \left( {{{n - s} \over r}} \right)^{\,2} } - \left( {{{n - s} \over r}} \right)\arccos \left( {{{n - s} \over r}} \right)} \right) \cr} we can integrate the above for $$0 \le s < 1/2$$, with due consideration for the variation in $$s$$ of the intervals:
the $$n$$ indicated above may vary $$\pm 1$$ at varying $$s$$, which will require to split the integral.
• This is fantastic. The diagram is incredibly illustrative. Thank you for such a thorough explanation! – 0k33 Nov 27 '18 at 3:32
• @Ok33: actually, in my previous version, I missed some important details: sorry. I re-casted the answer to deal more precisely with them. – G Cab Nov 28 '18 at 15:20
• @G Cab thank you so much for the follow up! – 0k33 Nov 29 '18 at 23:58
• @Ok33 : the argument was interesting for me as well, but it is a pleasure to help people so nice to leave a thank! – G Cab Nov 30 '18 at 0:32 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 55, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9899411201477051, "perplexity": 348.70203314683476}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-22/segments/1558232255536.6/warc/CC-MAIN-20190520021654-20190520043654-00366.warc.gz"} |
http://www.cs.cornell.edu/Info/People/raman/phd-thesis/html/node23.html | Refining the quasi-prefix form
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Next: Constructing high-level representations Up: Representing mathematical content Previous: Math object encapsulates
## Refining the quasi-prefix form
In s:high-level-models, we mentioned that all objects in our document model are linked. This is true of the objects appearing in the quasi-prefix representation. Each node in the tree is linked to its parent, as well as to its previous and next siblings. Math attributes have their parent link set to the object being attributed.
We refine the quasi-prefix form by adding the following subtypes. This makes recognizing and handling complex mathematical content cleaner.
We first introduce object math subformula, which is used to capture subexpressions appearing within the [tex2html_wrap5306] and [tex2html_wrap5308] of La)TeX. Object math subformula can be thought of as being the math equivalent of object text block described in s:high-level-models. It has the following structure:
• Attribute: Visual attributes.
• Content: The mathematical content represented as a math object.
Object math subformula can be intuitively thought of as a dummy object that encapsulates an expression.
We need object math subformula to represent expressions of the form:
[displaymath5302]
[displaymath5303]
In representing each of the above examples, object math subformula is essential in capturing the expression to which the overbrace/underbrace applies.
To enable recognition of written mathematics, tokens have to be appropriately classified. Our classification of tokens when processing written mathematics is inspired by appendix F of the TeX Book, [Knu84].
The symbols divide naturally into groups based on their mathematical class (Ord, Op, Bin, Rel, Open, Close, or Punct), [tex2html_wrap5310]
We introduce subtypes of object math object to correspond to each token type:
• Ordinary: TeX ord. Letters, numbers and some miscellaneous symbols.
• Big operator: TeX Op. The large operators that typically appear as unary operators, e.g., [tex2html_wrap5312], [tex2html_wrap5314], [tex2html_wrap5316].
• Binary operator: TeX Bin. The binary operators, e.g., +, [tex2html_wrap5320].
• Relational operator: TeX Rel, e.g., <, [tex2html_wrap5324]. We subdivide the TeX Rel class into relational and arrow operators.
• Arrow operators: Arrows such as [tex2html_wrap5326], [tex2html_wrap5328].
• Mathematical function: Plain TeX and LaTeX define [tex2html_wrap5330] etc. as macros. We introduce an object type, mathematical function to represent these.
• Open delimiter: TeX Open, e.g., [tex2html_wrap5332], [tex2html_wrap5334].
• Close delimiter: TeX Close, e.g., [tex2html_wrap5336], [tex2html_wrap5338].
• Math punctuation : TeX Punct -punctuation marks.
Written mathematical notation uses juxtaposition as an infix operator. Juxtaposition, as in [tex2html_wrap5340], mostly denotes multiplication, but can mean function application in certain contexts -[tex2html_wrap5342]. We introduce a new operator to represent juxtaposition, and to define it precisely, we also assert that all mathematical variables are single letters. Thus, [tex2html_wrap5344] is represented as the juxtaposition of three ordinary objects. This assertion is not specific to our internal representation, rather, it specifies the concrete syntax used in the electronic markup and reflects the choice made in the design of TeX. We do allow mathematical variables made up of more than one character, but these should be clearly marked up as such, e.g., as [tex2html_wrap5346], by using `\mbox` as in `\$\mbox{cab}=cab\$`.
The classification of a math object is defined using the following command: (define-math-classification token classification)
In certain special cases, the predefined classification shown above can be modified. A good example of this is recognizing a mathematical text that consistently uses the letters [tex2html_wrap5348], [tex2html_wrap5350] and [tex2html_wrap5352] to denote functions. Using the predefined classification, the recognizer would treat [tex2html_wrap5354] as object ordinary, leading to [tex2html_wrap5356] being represented as the juxtaposition of two objects, namely, [tex2html_wrap5358] and [tex2html_wrap5360]. Declaring [tex2html_wrap5362] to be a mathematical function by executing (define-math-classification f mathematical-function-name)
results in occurrences of [tex2html_wrap5364] being treated as a function. Hence, [tex2html_wrap5366] is correctly recognized as a function application. Note that the correct interpretation of such notation is more important for browsing than for speaking the expression.
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Next: Constructing high-level representations Up: Representing mathematical content Previous: Math object encapsulates
TV Raman
Thu Mar 9 20:10:41 EST 1995 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9827204346656799, "perplexity": 4931.617588170709}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368699798457/warc/CC-MAIN-20130516102318-00037-ip-10-60-113-184.ec2.internal.warc.gz"} |
https://samjshah.com/2009/10/26/writing-in-algebra-2/ | # Writing in Algebra 2
One of my pushes this year is to get my Algebra II students to write math better. Last year I put “explain this” problems on a few exams and wasn’t so impressed with their responses. This year I am teaching my kids to write responses.
On their first assessment, I put a question similar to one we talked about in class:
Explain to someone who doesn’t know a lot about math why you can never find an $x$ which would make $|25x+5.1|-5=-6$.
The responses were disappointing across the board. There were bits and pieces of gems, but nothing complete. Not a single student was able to construct a well-written response. Things I received included:
• The other side of the equation is negative, leaving no possible solution to the problem.
• You can never find x because the answer is negative and an absolute value problem with a negative after the equal sign is not possible.
So what I did was type up the following document and passed it out a few days after the assessment:
We talked about the vagueness of the responses, the use of pronouns like “it” and making references to “the other side of the equation,” and most crucial, the lack of reference in almost every solution to the original equation. How can you answer a question about an equation without even talking about the equation?
My favorite moment of the discussion this generated was when one student raised her hand and critiqued her own solution, and then said: “I wrote this and don’t even know what I meant.”
On the next assessment, without telling them I was going to do this, I threw the exact same question down. It was on. I saw my kids reread their responses after they wrote them, and really pay attention to their writing. Let me tell you: it all paid off. On this second round, most students got full marks. (On the first assessment, almost no one got full marks, or close to it, for that matter.)
Here are some random smatterings of their thoughtful answers:
• You could never find an $x$ to make the absolute value equation above true because you would have to subtract -5 from -6, which still gives you a negative number. $|-25x+5.1|=-1$. An absolute value equation cannot equal a negative number because absolute value is the distance from zero and is always positive [my correction: or zero].
• In this absolute value equation there is no solution because any number in the absolute value has to be 0 or a positive number. And if you subtract 5 from 0 or a positive number, there is no possible way that can equal -6. So there is no solution to this equation.
• An absolute value of anything can never be equal to a negative number, since it expresses a distance. When this equation is simplified, it becomes $|-25x+5.1|=-1$. If the ‘-1’ were replaced with a positive number, you could find the answer [for] $x$. But since it is a negative, you already know that is impossible.
I am continuing to ask them to express themselves through writing. On that same assessment where I asked them to repeat the absolute value problem, I also asked the following two questions, to which I got some really nice writups.
The following two questions build upon each other. The solution to part (a) will very much help you explain part (b).
(a) Explain why $a^2a^4=a^6$ without using your exponent rules. Explain it to someone so they can understand it simply!
(b) Explain why $a^ma^n=a^{m+n}$ is true. You can assume $m$ and $n$ are positive integers. Explain it to someone so they can understand it simply!
I still have to do more work with this, but I just wanted to say: it is worth it to talk with your kids about writing. One 15/20 minute conversation has already yielded great dividends for me.
1. This is really good, especially your discussion of what was weak about your students’ initial answers (vague, using unclear pronouns like “it,” etc.). I can imagine this was very helpful for them. I suspect that a lot of your students really did understand why the equation had no solution, they just didn’t communicate it very well. Students need to be reminded (and taught!) that just because something is clear to them inside their own head, they still have to work at making it clear to someone else.
(BTW, the footnote in the Scribd doc was a little unclear; I suspect you and your students understood it, but just made me wonder what “question 27” was.)
“Almost no one in the class got full credit for this problem. But that was expected because I haven’t “taught” you to write good explanations yet. (That is the reason why I made question 27 “extra credit.” Surprisingly, most all of you wrote really cogent and wonderful explanations for that problem.) The 9 solutions that I picked to share were totally random.”
Question 27 was:
27. Explain why the following is WRONG:
If I have the compound inequality x>3 AND x3 AND x<=3 simply gives you all real numbers. To explain further, it is all numbers greater than 3 and all numbers less than or equal to three. All the real numbers.
2. Chris says:
I think one of the important reasons to be asking students to write about math is because it reinforces the (often forgotten) fact that the math they’re learning isn’t just a random collection of facts. They may know how to manipulate formulas, but asking them to step back and think about what they’re saying brings home that this is a logical problem-solving framework we’re developing.
That and the fact that expressing oneself clearly is a key skill in the “real world”, no matter what the subject is.
3. H. says:
Thanks for posting this. I’ve been reluctant to try to teach math writing because … I know I don’t know how to teach it. But if a class discussion of samples of the students’ own work helps, there’s no reason not to have a go at it.
4. MsAxthelm says:
Thanks for the post!
I have been working with the 9th graders I am student teaching with to try to improve their writing and reading comprehension skills in math class. The textbook is difficult to read but key to all the lessons. I did a readability test of the textbook and found that the book is between level 11 (junior in high school) to 15 (yep – junior in college) – so the reading level is much higher than these 9th graders need. Not only does the textbook require a lot of reading, all the math problems require explanations – which is good except the students don’t know how to compose them. It seems the question of “is it reading comprehension?” and “is it their writing skills?” or “is it the math concepts?” is pertinent here.
My first try at improving writing was to outline and discuss the elements of an argument. After a quick discussion, we watched a TED video where Art Benjamin argues that statistics, not calculus, should be the pinnacle of high school math [1] and picked out the different elements of his argument. (I don’t know that I have formed an opinion on this, yet, but it made sense to the students since they have gone through one unit of algebra and one unit of statistics, thus far. So they were basically comparing the two units to form their own opinions.) I then had them write an argument of their own.
First drafts not so good, but I plan to work on them one-on-one during independent work time. I hope it can lead to some better “explain” responses in the homework, quizzes, and tests.
Challenge: I am not a language arts teacher! I want to emphasize having a claim and support for that claim, but I don’t know how to teach grammar and sentence structure. Should I be? Do I just go to the real Lang Arts teachers and ask them what to do? What next? Ideas?
Love the sharing,
Joan
5. Hey, my name is Jordan, and I’d just like to say that finding this post has been EXTREMELY helpful for me. I am currently enrolled in a grad school class called “Teaching Interdisciplinary Writing.” Right now, I’m working on a project where I have to create the syllabus and several lesson plans for an imaginary class in Writing in Algebra.
I am an English major. The last time I took any kind of math class was back in high school, and even then, I didn’t “get it.” This project, then, is a tough one for me. But here I find you, a real life Algebra teacher, and you are teaching your students to “write math!” !!!!!! This is a huge thing for me!
Bottom line: could I convince you to mentor me, briefly, with this class I’m creating? I would love the opportunity to hear and learn from more of your experiences in teaching writing to math students. I don’t know if you even check these pages of your blog any more, but if you do, and you are willing to be the Yoda to my Luke, my email address is [email protected].
Thank you! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 10, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5936340689659119, "perplexity": 594.1672815243284}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084887746.35/warc/CC-MAIN-20180119045937-20180119065937-00027.warc.gz"} |
http://cms.math.ca/cmb/kw/nilpotent | location: Publications → journals
Search results
Search: All articles in the CMB digital archive with keyword nilpotent
Expand all Collapse all Results 1 - 8 of 8
1. CMB 2014 (vol 57 pp. 884)
Xu, Yong; Zhang, Xinjian
$m$-embedded Subgroups and $p$-nilpotency of Finite Groups Let $A$ be a subgroup of a finite group $G$ and $\Sigma : G_0\leq G_1\leq\cdots \leq G_n$ some subgroup series of $G$. Suppose that for each pair $(K,H)$ such that $K$ is a maximal subgroup of $H$ and $G_{i-1}\leq K \lt H\leq G_i$, for some $i$, either $A\cap H = A\cap K$ or $AH = AK$. Then $A$ is said to be $\Sigma$-embedded in $G$; $A$ is said to be $m$-embedded in $G$ if $G$ has a subnormal subgroup $T$ and a $\{1\leq G\}$-embedded subgroup $C$ in $G$ such that $G = AT$ and $T\cap A\leq C\leq A$. In this article, some sufficient conditions for a finite group $G$ to be $p$-nilpotent are given whenever all subgroups with order $p^{k}$ of a Sylow $p$-subgroup of $G$ are $m$-embedded for a given positive integer $k$. Keywords:finite group, $p$-nilpotent group, $m$-embedded subgroupCategories:20D10, 20D15
2. CMB 2013 (vol 57 pp. 125)
Mlaiki, Nabil M.
Camina Triples In this paper, we study Camina triples. Camina triples are a generalization of Camina pairs. Camina pairs were first introduced in 1978 by A .R. Camina. Camina's work was inspired by the study of Frobenius groups. We show that if $(G,N,M)$ is a Camina triple, then either $G/N$ is a $p$-group, or $M$ is abelian, or $M$ has a non-trivial nilpotent or Frobenius quotient. Keywords:Camina triples, Camina pairs, nilpotent groups, vanishing off subgroup, irreducible characters, solvable groupsCategory:20D15
3. CMB 2012 (vol 56 pp. 606)
Mazorchuk, Volodymyr; Zhao, Kaiming
Characterization of Simple Highest Weight Modules We prove that for simple complex finite dimensional Lie algebras, affine Kac-Moody Lie algebras, the Virasoro algebra and the Heisenberg-Virasoro algebra, simple highest weight modules are characterized by the property that all positive root elements act on these modules locally nilpotently. We also show that this is not the case for higher rank Virasoro and for Heisenberg algebras. Keywords:Lie algebra, highest weight module, triangular decomposition, locally nilpotent actionCategories:17B20, 17B65, 17B66, 17B68
4. CMB 2011 (vol 55 pp. 579)
Ndogmo, J. C.
Casimir Operators and Nilpotent Radicals It is shown that a Lie algebra having a nilpotent radical has a fundamental set of invariants consisting of Casimir operators. A different proof is given in the well known special case of an abelian radical. A result relating the number of invariants to the dimension of the Cartan subalgebra is also established. Keywords:nilpotent radical, Casimir operators, algebraic Lie algebras, Cartan subalgebras, number of invariantsCategories:16W25, 17B45, 16S30
5. CMB 2009 (vol 52 pp. 535)
Daigle, Daniel; Kaliman, Shulim
A Note on Locally Nilpotent Derivations\\ and Variables of $k[X,Y,Z]$ We strengthen certain results concerning actions of $(\Comp,+)$ on $\Comp^{3}$ and embeddings of $\Comp^{2}$ in $\Comp^{3}$, and show that these results are in fact valid over any field of characteristic zero. Keywords:locally nilpotent derivations, group actions, polynomial automorphisms, variable, affine spaceCategories:14R10, 14R20, 14R25, 13N15
6. CMB 2004 (vol 47 pp. 343)
Drensky, Vesselin; Hammoudi, Lakhdar
Combinatorics of Words and Semigroup Algebras Which Are Sums of Locally Nilpotent Subalgebras We construct new examples of non-nil algebras with any number of generators, which are direct sums of two locally nilpotent subalgebras. Like all previously known examples, our examples are contracted semigroup algebras and the underlying semigroups are unions of locally nilpotent subsemigroups. In our constructions we make more transparent than in the past the close relationship between the considered problem and combinatorics of words. Keywords:locally nilpotent rings,, nil rings, locally nilpotent semigroups,, semigroup algebras, monomial algebras, infinite wordsCategories:16N40, 16S15, 20M05, 20M25, 68R15
7. CMB 2001 (vol 44 pp. 266)
Cencelj, M.; Dranishnikov, A. N.
Extension of Maps to Nilpotent Spaces We show that every compactum has cohomological dimension $1$ with respect to a finitely generated nilpotent group $G$ whenever it has cohomological dimension $1$ with respect to the abelianization of $G$. This is applied to the extension theory to obtain a cohomological dimension theory condition for a finite-dimensional compactum $X$ for extendability of every map from a closed subset of $X$ into a nilpotent $\CW$-complex $M$ with finitely generated homotopy groups over all of $X$. Keywords:cohomological dimension, extension of maps, nilpotent group, nilpotent spaceCategories:55M10, 55S36, 54C20, 54F45
8. CMB 1999 (vol 42 pp. 335)
Kim, Goansu; Tang, C. Y.
Cyclic Subgroup Separability of HNN-Extensions with Cyclic Associated Subgroups We derive a necessary and sufficient condition for HNN-extensions of cyclic subgroup separable groups with cyclic associated subgroups to be cyclic subgroup separable. Applying this, we explicitly characterize the residual finiteness and the cyclic subgroup separability of HNN-extensions of abelian groups with cyclic associated subgroups. We also consider these residual properties of HNN-extensions of nilpotent groups with cyclic associated subgroups. Keywords:HNN-extension, nilpotent groups, cyclic subgroup separable $(\pi_c)$, residually finiteCategories:20E26, 20E06, 20F10
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http://hydraraptor.blogspot.ie/2007/ | ## Sunday, 30 December 2007
### Running repairs
No sooner than I had fixed my heater, the extruder motor failed!
I bodged the heater connection by putting some more solder on it. It's not a permanent solution because the solder is molten while the heater is on so it slowly oxidizes away. The last time bodged it that way it lasted six months though. It really needs a crimped connection.
The GM3 motor failed by running slowly, getting very hot and drawing lots of current. It eventually caused the protected MOSFET that is driving it to shut down. Opening it up soon revealed how it had failed :-
It has two pairs of copper brushes. Three of them have holes worn right through and the fourth has broken off. Its stub was touching the wrong side of the commutator, causing a short.
More expensive motors have carbon blocks on the end of arms which can wear down a lot further before they fail. Bigger motors have spring loaded carbon rods. The gearbox shows no sign of wear so it is let down by the cheap motor.
This motor is not really up to the job of driving the extruder. It is being severely abused by running it from 12V PWM when it is only rated at 6V. I anticipated it would not last long and ordered a spare when I bought it. I fitted that and HydraRaptor is up and running again. Curiously the second motor seems a lot quieter than the first.
At some point I think I will upgrade to a stepper motor. They are more expensive but, as long as you don't load the bearings, they last virtually forever. In the long run they probably work out cheaper and I can also dispense with the shaft encoder and the interference suppressor.
## Friday, 28 December 2007
### Wear and tear
My extruder's heater went open circuit so I removed the heat shield to have a look at it. I have actually run it for many hours now and have extruded quite a lot of HDPE. I have about 200g of extruded test objects and scrap which represents about 13 hours operation. I only recently started saving my scrap so I must have extruded a lot more. The 2.5Kg reel of HDPE is noticeably smaller.
The heater has also run for a lot longer than the extruder has been extruding. I got fed up of waiting for it to warm up at the start of each run so my host software leaves it on. I keep meaning to put a timeout in the firmware to turn it off when there hasn't been any Ethernet messages for a while as I have left it on for long periods a few times.
The extruder is starting to show some signs of aging. The plastic shield which keeps the fan draft away from the nozzle looked like this when I made it :-
But now it looks like this :-
The nozzle itself now looks like this :-
The JBWeld that surrounds the heater wire has gone very dark and has several cracks in it. One of the heater connections broke off in a previous accident so I dug it out and joined a piece of copper wire by squeezing it tight and soldering it. There is now no sign of the solder which is why it has gone open circuit.
The black stuff which looks like bitumen must be slow cooked HDPE. I am surprised that long term heating to 240°C causes it to decompose. I don't know if the white surface on the shield is just due to its surface melting a bit or whether something boiled off the nozzle and condensed onto it or reacted with it.
Even the high temp insulation over the thermistor wires is starting to look a bit sad!
I also noticed that the steel wire that forms the flexible drive coupling is starting to break up. A couple of strands have snapped and there is a pile of black dust on top of the pump shell.
The heater connection should be easy to fix. I have a few planned improvements to make to the extruder but I will wait till parts wear out before replacing them with better ones to get the most use of it.
### To raft or not to raft?
When extruding HDPE onto foam board a raft needs to be laid down first to increase the anchorage at the corners to reduce curling. It becomes part of the object and has to be trimmed back to its outline with scissors or a knife. Now that I am extruding onto polypropylene cutting board I wondered if it was still necessary.
The temperature at which I lay down HDPE onto the cutting board is important. At 180°C it does not stick. At 200°C it sticks well but can be peeled off with the help of a penknife. Higher temperatures make it harder to remove and do more damage to the board.
Here are a couple of 15mm test cubes made directly onto the PP board without a raft :-
The one on the left had the first layer extruded at 200°C and subsequent layers at 240°C. As you can see it curled badly, particularly at one corner. The one on the right had its first layer extruded at 220°C. It looked promising but when I tried my standard warp test block the result was not good!
So it looks like the raft is here to stay. Here is an example :-
I lay down the raft at 4mm/s with a notional filament diameter of 1.1mm with the extruder head 1.3mm above the board. This is to get the filament as round as possible so that it doesn't form a solid weld. In actual fact, gravity causes it to slump to about 0.9mm high and spread to 1.3mm wide. The oval area calculation would give 1.34mm and a pitch of 1.3mm is sufficient to get adjacent filaments to stick together. My rationale for making the raft as thick as possible in one layer was to make it strong without taking too much time. It probably does not need to be as strong now that it binds to the PP.
I put the raft down at 200°C, then I do the first layer of the object at 240°C with the fan off to ensure it welds to the raft and then subsequent layers at 240°C with the fan on.
I calculate the amount the raft overlaps the object with this completely arbitrary function :-
def overlap(x): return x + 10 + 10.0 * (x - 20) / 80
I halved the overlap when I went from foam board to polypropylene.
## Thursday, 27 December 2007
### Cutting corners
When making solid blocks with 0.5mm HDPE filament I noticed that the corners are not very accurate. The right hand edge of the 20mm cube below shows this effect at its worst :-
The problem is that, although the machine makes a perfect right angle, the filament appears to have a minimum bend radius and so cuts the corner. The amount it cuts the corner seems to vary from layer to layer giving rise to the rough edge.
I think the variation is due to the fact that my extruder spindle is a bit off centre. This causes the torque to go up and down as it rotates, which causes the flexible drive cable to wind up and run down again. This causes speed variations despite the fact that the motor speed is well regulated. At some point I will get rid of the flexible drive.
I expect the fact that I am stretching the filament doesn't help with the corner cutting. I improved it a lot by slowing down the drawing of the outline to 4mm/s and leaving the infill at 16mm/s. Here is the result :-
Still not perfect, another thing to try would be to recognise that there is a minimum corner radius and make the nozzle follow an arc of that radius around the corner. At least that way it might be more uniform.
Here is a close up of the top face taken with a scanner:-
As it goes round the corner the filament has an external radius of about 1.5mm and an internal radius of 0.9mm. As it is 0.6mm wide that is probably not bad. You can also see that the zigzag infill sometimes ends a bit short of the edge, probably also due to corner cutting.
To get sharper corners I expect I need to use a nozzle with a smaller hole, so that the filament can be fine without having to be stretched, but that has the disadvantage of slowing down the extrusion rate for a given pressure.
## Wednesday, 26 December 2007
### Warped
Having got an idea of the HDPE warping for thin walled open boxes, I decided to start investigating solid shapes. I made a solid block 40 x 10 x 20mm to compare with the open boxes of the same dimensions.
Obviously there are many ways to fill the interior so I started with the simplest, just alternate layers of horizontal and vertical zigzags. HydraRaptor seems quite happy extruding 0.5mm diameter filament at 16 mm / second. If extruded into free air it would actually be 1mm at 4mm/s, but that is too course, so I move the head at 16mm/s which stretches it.
From trial and error I have found that a good layer height to use is 0.8 times the notional filament diameter. If it is more, then as the lower layers shrink, the nozzle rises faster than the object and a gap develops. Once that happens the filament squirms about and does not follow the path of the nozzle accurately.
So the extruded filament is constrained to 0.4mm high. Measurements show the width to be about 0.6mm. Incidentally, if it squashed to a perfect ellipse with a height of 0.4mm then it would be 0.625mm wide to have the same area as a 0.5mm circle. I extrude the zigzag with a pitch of 0.6mm so that adjacent filaments touch, but it means the object is not actually completely solid. The space occupied by each filament is a rectangular channel 0.4 x 0.6 = 0.24mm² but the cross sectional area of the plastic is π x 0.25² = 0.20mm², so about 18% is air. I confirmed this by weighing the block. It weighs 6.5g but if it was solid HDPE then 8ml would weight about 8g. It takes about 45 minutes to make the object including laying a raft.
Before I tried it, I always imagined the amount of plastic deposited would have to exactly match the volume of the extruded object otherwise it would sag or bulge. I could never understand how FDM worked reliably. Now I know that the volume can be a bit less and the difference is made up by air. That means the amount of plastic deposited is actually not that critical, which is why RepRap can get away with an open loop extruder.
I measured the warping with the three nail jig that I showed in the last post. The thin walled box is warped 0.44mm and the solid box has warped 0.87mm so that answers the question whether solid objects warp more or less. Note that the thin walled box is made with 1mm filament because 0.5mm filament is too thin to be self supporting.
I expect I can make a less warped block by extruding a thick base and then a less dense infill above that. Something else to try.
It is amazing how strong 10mm thick HDPE is. You don't often get to see plastics in that form. Most end products have optimised strength against cost by having thin walls and ribs etc.
## Sunday, 16 December 2007
### Chopping up chopping boards
Up until now I have been extruding HDPE onto foam board because it was the only thing that it sticks to well enough. However, it has a couple of failings: It is not strong enough to completely resist the warping caused by the HDPE and it is not reusable because the surface gets ripped off.
I have tried many other surfaces including various woods and metals (with and without primer), melamine and several other types of foam board but nothing worked. Obviously HDPE sticks to HDPE so I decided to investigate that further.
My first idea was to use a thin sheet of HDPE cut from a milk bottle. This makes a nice surface to extrude onto but the problem is holding it down. I first stuck it down with double sided tape but the heat melts the glue. Sticking it to a sheet of aluminium to take the heat away improved matters and I was able to get slightly less warping than with foam board.
To compare the warping on different base materials I made a test shape that is a 40mm x 10mm x 20mm open box with 1mm walls and measured how much the corners lift using a simple jig.
With foam board I was getting 0.83mm lift between corners and the middle. With HDPE stuck to aluminium I got 0.76mm. Not much better because the glue of the sticky tape stretches under the curling force.
I needed a thick HDPE base and I had heard that plastic kitchen chopping boards are made from HDPE. I bought a new one from ASDA which looks like this :-
It is 5mm thick, opaque and quite rigid. I realised it was very different from the other chopping boards we have which I think came from IKEA.
These are 10mm thick and made from a softer, more translucent plastic. To find out which was HDPE I used the flow chart on this website www.texloc.com/ztextonly/clplasticid.htm. I concluded the thin hard one from ASDA is HDPE and the thicker softer one from IKEA is PP. HDPE seems to stick equally well to both of them but the HDPE one warped a bit when it was only held down with masking tape, so I decided to go with the PP one. I cut it up and bolted it down to my XY-table. It was a bit curved due to years of dishwasher use but bolting it down pulled it flat.
Surprisingly, if I lay down a raft at 200°C it sticks well but can be easily prized off again with a penknife. The board is marked slightly but it can be reused over and over again.
I extrude the object at 240°C so that it welds to the raft and itself, and I turn the fan on after the first layer so that the object cools to room temp as fast as possible.
The board is strong enough to hold the object completely flat while it is attached but when it is removed it does still curl a bit. I measured 0.44mm on my jig so that is about half the curling I was getting with foam board. Other than extruding onto a convex surface, I think that is the best that can be achieved for that shape with HDPE at room temperature. Here are the three tests side by side :-
Next I will look at different solid shapes to see if they warp more or less.
## Tuesday, 13 November 2007
### Disaster recovery
I am pleased to say HydraRaptor is now back up and running after my accident where I connected 240V to a 3.3V logic input. I had to replace most of the electronics, which is annoying because I originally made it out of things I already had, so it cost me nothing, but replacement parts cost me around £180 and obtaining them set me back three weeks.
Things that were destroyed:
• My ADSL router: a friend kindly gave me a replacement.
• My PC's serial port: I replaced it with a USB to serial adapter.
• The Freescale DEMO9S12NE64 evaluation board that I used for my axis controller: next day delivery from Farnell.
• The EZ430-T2012 eval board that I used for the extruder controller, fortunately the spindle controller was not connected at the time so that survived.
• The ULN2803 and 7407 chips on my interface board.
• The optical shaft encoder chip on my extruder.
• The NEAT MDM7 stepper driver on the X axis. The only thing wrong with it was the direction input was not working. They are opto coupled so it should have been just a simple matter of replacing the opto, but the whole thing is potted in epoxy resin so it is impossible to fix. I managed to find a replacement on the web and I have got some spares on the way as well.
Things that survived:
• Both power supplies and all the local voltage regulators.
• The Y axis stepper driver.
• The X-Y table shaft encoders and Hall effect limit switches.
• The protected MOSFETs on the extruder controller.
I spent the time waiting for the stepper controller to arrive from the US improving my firmware. I fixed a long standing issue with timing: I was doing my Ethernet comms under interrupt and the stepper motor timing with a higher priority timer interrupt. Unfortunately, the 9S12 does not have nested interrupts, so the interrupt priority is pretty meaningless. I fixed it by moving my comms to the foreground as the machine has nothing else to do in the foreground but process commands coming from the network so there was no point in doing it with interrupts.
I also added acceleration and deceleration to my stepper driving software. I am aiming to lay down 0.25mm filament at 64mm/s. My XY table can easily move that fast but I didn't like the thump I was getting when it started and stopped. It's a bit much to ask it to accelerate a few kilograms to 64mm/s instantly! The datagram for the goto_xyz command now includes a table of delays to use for the first and last n steps. It remains to be seen how much distortion I will get from not moving at constant velocity. At the very least the acceleration will be useful in speeding up the moves when it is not extruding.
## Saturday, 27 October 2007
### Extruder dimensions
I have been asked for dimensioned drawings of the extruder. I made these by manually inspecting the 3D models in ArtOfIllusion. It is not the easiest application for extracting dimensions so I made 2D drawings in Visio which does have good dimensioning tools. I then made Python scrips to do the milling. My dimensions may differ in places but I did make the extruder from these drawings and it does work. I tightened up some of the hole clearances because my milling machine holds much tighter tolerance than FDM.
This is the motor shaft coupler. I adjusted the slot to suit my GM3 motor. I think there are now two versions of this part. The official design is tapered but this is not necessary with the offset motor mount so I simplified it to a cylinder.
Here is the finished article milled with a 2.22 mm bit. The step on the outside and in the shaft slot are there because my milling tool's shaft is wider than the bit, so to go deeper than 9mm I need to have some clearance. The material is some sort of metal loaded resin.
Here is the clamp drawing I used. It has now been superseded by a larger design. Note that I adjusted the hole for the PTFE to suit my 12mm rod. I think the official design was 10mm but is now 16mm. I also widened the slot to allow the 2.2mm milling tool to get in and added some extra mounting holes to suit my machine.
I milled it from 9mm Delrin.
Here is the pump drawing :-
The poly channel on the official version slopes outwards at the entry but that is only needed for the version without the offset motor.
And here is the milled version :-
The material I used is not as slippery as CAPA so, to reduce friction in the channel, I smoothed it with emery paper, polished it with metal polish and sprayed it with PTFE dry film spray.
I split the motor mount into three pieces for milling from a sheet of 5mm perspex. I fixed the pieces together with M2.5 screws, tapped into the perspex.
If anybody wants the Visio source file it is here:- forums.reprap.org
## Tuesday, 23 October 2007
### They don't like it up 'em!
How is this for bad luck :-
I was trying to connect a scope probe to the far side of a two row connector on my machine. I made a small hook from a piece of wire with a bit of insulation to get it past the front row.
I inserted this with the power turned off. Unfortunatly, and almost unbelievably, the far end of the wire manage to find its way into a hole leading to the mains live terminal on my solid state relay. That was the only thing on the live side of the mains switch.
Massive bang! Blew the crap out of HydraRaptor and my ADSL router. My PC is crippled is well, it no longer runs at the correct front side bus speed and insists I haven't got an 80 pin IDE cable.
This is the CPU of my axis controller :-
And this the micro from my extruder controller :-
I expect all the rest of the electronics is fried as well, so pretty much the end of HydraRaptor. The only lucky thing was that I was holding the insulation, otherwise it might have been the end of me as well!
### Stretching a point
In his article: x-idler-bracket-continued Vik Olliver alluded to the fact that you can extrude filament with a smaller diameter than the hole in the nozzle. I did some experiments to see how fine I could go. In fact the final filament diameter is simply determined by the feed rate of the extruder and the travel rate of the nozzle, or in my case the bed. The filament stretches to the length that matches the rate of travel while it is still liquid. You can then calculate the mean diameter from the volume of material extruded. The nozzle height has to be a bit less than that mean diameter and then the width becomes a bit wider.
Here are three 20 x 20 x 20 open cubes with different wall thicknesses :-
The first was 1mm diameter filament extruded at 4mm per second with a height of 0.8mm giving a wall thickness of about 1.2mm.
The second was the same feed rate but with the extruder traveling over the bed at 16mm per second to give 0.5mm filament, the same as the nozzle hole diameter. The height was set to 0.4mm giving a wall thickness of about 0.6mm. As you can see it warps more but I expect it would behave if it was building a solid object. The bottom layer which was stuck to the table has better corner definition.
The third attempt was 0.35mm filament extruded at 16mm per second with a hight of 0.28mm and a width of about 0.5mm. As you can see holes started appearing but I think that was just because the sides buckled so badly. Interestingly the holes can be bridged by filament above that needs no support. Again, I think this would be OK making solid objects, or at least objects with thicker walls.
This is really good news as it means I can get down to the sort of resolution commercial machines get (0.25mm) without having to have a very small nozzle aperture, which would limit the flow rate. It remains to be seen what effect stretching has on the polymer but as it is still liquid at that point I think it wont increase the contraction much, if at all. It does mean I need very fast head movement to keep up the deposition rate, about 64mm per second. I think my machine will do that if I reconfigure the steppers for speed rather than torque, a simple one wire change.
## Tuesday, 16 October 2007
### Scaling new heights
In my article laying-it-on-the-line I showed how I arrived at this test shape, a 20mm open ended cube :-
I decided to try different sized shapes to see how the process scales. It turns out that it doesn't and 20mm cubed is the magic size that is easiest to make!
The first thing I tried was taller :-
As you can see at 50mm tall it is starting to sag and 100mm is hopeless. The problem is that as the height increases, the plastic already laid down contracts as it cools and leaves the nozzle high and dry. I fixed that be reducing the Z increment from 1mm per layer to 0.95mm. That allowed me to make a good 20 x 20 x 95mm square tube :-
I presume with this increment I can keep going up, but who knows, I thought that at 20mm!
Next I tried low and wide. This was an attempt to make 120 x 120 x 20mm :-
I stopped it when the first two layers failed to weld. This was because with an object this large, by the time it has traced the perimeter to start the next layer, the first layer has cooled down to room temperature. In my post sticking point I predicted that to make an instantaneous weld between molten plastic and plastic at room temperature requires the molten plastic to be at temperature
T = 2 x Tm - Tr, for HDPE and 20°C this means about 240 - 250°C.
I set my extruder to 240°C and made this mess :-
I don't like running the extruder that hot because, although HDPE is not supposed to burn until 350°C, it smells like burning plastic and the end of the nozzle is glazed black. Also, the toothbrush that wipes the nozzle is showing signs of melting.
The object came unstuck from the foam board because of the extreme corner curling due to shrinkage. This is a fundamental problem with HDPE and room temperature FDM. HDPE shrinks about 2% when it cools from its melting point to room temperature. Commercial FDM machines use ABS, which has a lower shrinkage, and they keep the work piece in an oven close to the melting point. That means the hot plastic does not need to be so much hotter than the melting point, and most of the shrinkage occurs after the object is complete. The problem here is that the first layer cools and shrinks before the next layer lands of top. The next layer is bigger when it welds on top but then it shrinks, contracting the bottom layer more. Each subsequent layer increases the tension on the layers below. The bigger the object is, the worse the effect is because the mismatch between the size of the hot layer and the cold layer below it is bigger in absolute terms.
Following in Forrest's footsteps I tried laying down a raft of HDPE first to anchor the object to the foam base. The raft is 120 x 120mm but the object is now only 100 x 100 x 20mm.
As you can see that gives a big improvement but it wasn't strong enough to hold the corners down fully. A bigger raft, and perhaps a second layer might help but as it was an hour to build the raft and half an hour to build the object I didn't bother trying again. The blob, by the way, is where the firmware crashed on the last layer!
Here are some 40 x 40 x 20mm tests made with rafts, the second one had a bigger raft:-
Here the corner curl with a raft is comparable to the 20 x 20 x 20mm test without a raft showing how this effect gets dramatically worse as width increases.
Next I tried tall thin objects :-
Both were made on rafts and, the first is 15 x 15x x 75 mm, the second is 10 x 10 x 100mm. The photo is not very good but they both flare towards the bottom. The one on the left has an untidy surface as each layer is not well aligned with the layer below it and the one of the right has a completely wavy surface like basket work.
The reason for this is that because the perimeter is shorter, the layer below is still molten when the next layer is extruded on top of it. It moves around giving an untidy surface and also does not resist the contraction of the layer above. The bottom few layers are the correct size because they are welded to the solid raft but the layers above are too small as they have contracted inwards. A 5 x 5mm test shows this effect even more :-
The only way around this is either to wait for the layer below to cool, speed up its cooling with a fan, or extrude very slowly. I decided to experiment with a fan. It was immediately obvious that if you have a fan blowing near the nozzle you have to insulate it otherwise it doesn't reach its target temperature.
The RepRap design uses fiberglass wool but I wanted to be able to see the state of my heater so I decided to make a transparent cover. I started with a plastic test tube, donated by my wife, which used to contain bath salts.
I cut the end off this and drilled a hole to clear the nozzle. I converted a large plastic nut into a mounting flange by stripping out the thread on my lathe so that it was a push fit.
Here it is mounted on the extruder :-
The first fan I tried was a small North bridge cooling fan. It was so light that I could mount it on a stiff wire attached by ring tail crimps and bolts. :-
Unfortunately it wasn't very powerful so the next fan I tried was a PC case fan complete with speed control and blue flashing LEDs.
This worked a lot better but it is difficult to get it as close as I would like it. Here is the tallest thing I have made so far, it is 10 x 10 x 150mm. At this point I changed to 4mm per second travel and a feed rate to give a 1mm filament. I found that you can get finer filament just by stretching it as it leaves the nozzle so the work I did with flow rate and filament size is not really relevant. I had to reduce the layer height to 0.8mm.
This worked well on the windward side, with a nice tight corner, but not so well on the leeward side. The corner away from the fan is more rounded and the layers are less tidy. A cross section shows that the two sides cooled by the fan are straighter and longer.
The 5 x 5 x 20mm test is much improved but its surface area is so small that the fan fails to keep it cool enough. I think the only option with something as small as this is to slow down, and possibly drop the temperature.
Again the leeward side is not as good. The filament short cuts the corner because the layer below is not strong enough to hold it in place. I think to make the fan effective a cowling and duct is needed to get a strong flow of air directed downwards around all sides of the nozzle.
I have noticed that there is always an excess of material at the corners. This is because the head makes a perfect right angle but the filament has a minimum bend radius and takes a short cut. I am not sure how to compensate for this. I can't really pause the extruder because its response is too slow, so I either have to speed the head up as it takes a corner, or perhaps make it move in an arc that matches the bend radius rather than a right angle.
And finally here is an improved version of the magic 20mm cube :-
This is with the benefit of a raft, finer filament and fan cooling. The corners are a bit sharper and the corner curling a bit less. The reasons why this turned out to be the optimum shape are :-
1. It is small enough that the filament does not cool too much when you go round it.
2. It is large enough to make it long enough to traverse so that it does not stay too hot.
3. It is short enough for the fan to be able to cool the back wall from the inside as well as the front.
4. It is small enough for corner curling to not be too extreme.
From these experiments I now think I have a good understanding of how the parameters: temperature, flow rate, traversal rate, z increment and fan use affect the result. I have only looked at thin walled boxes, I expect solid objects to add more thermal and contraction issues.
The only reason I am using HDPE is that it seems to be the only thermoplastic filament I can buy off the shelf in the UK without getting it specially made.
With a bit of trial and error I expect I could make the machine produce a wide range of shapes and some useful objects but therein lies the problem. It is not supposed to be trial and error. The dream is to be able to input an arbitrary 3D model, of any size within the build volume, and have the item appear a few hours later. At the moment I can't see how that can happen with room temperature extrusion of HDPE. Its melting point is too high and its contraction too great. Managing the temperature of the object being built is very tricky as the features of the object vary from large to small.
## Saturday, 13 October 2007
### GM3 motor suppressor
I have also been asked for more details on my motor suppression circuit that I first blogged in dc-to-daylight, so here goes :-
The Solarbotics GM3 generates large amounts of RF noise from 20MHz up to at least the TV band, which is 470- 850MHz in the UK. I know this because I can see the 20 MHz on my scope and it was also affecting our TV reception.
This is the circuit I used :-
The 1nF capacitors were axial ceramics and the 10nF was a radial ceramic, mainly because that is what I had to hand. I don't know the spec of the ferrite beads because I salvaged them from an old disc drive. Here is what they look like though :-
They should be a low Q type rated for at least 1A. The current rating is not so much about how much current they can carry but about the point where the magnetic field saturates the ferrite and the inductance disappears.
We want them to have a high impedance from 20 MHz to 800 MHz. I don't have much knowledge in this area but think this is quite a big ask for a ferrite and that I fell lucky with these. To get more impedance at the low frequency end it is normal to increase the number of turns to increase the inductance which is proportional to their square. The problem with that is that it increases the capacitance, reducing the attenuation at the high frequency end.
These beads are a good compromise: they have nearly a whole turn compared to a straight through bead which is half a turn, hence four times the inductance, but the wires maintain 0.1" separation so minimizing the capacitance.
The first two 1nF capacitors are soldered to the motor case. This is easier than you might imagine because steel is such a poor conductor of heat compared to copper, although it has to be said I am using a 50W temperature controller soldering iron. I cleaned the area first with a PCB cleaning block.
This is the rest of the circuit before it was soldered on top of the two capacitor leads. Spot my mistake!
Ignore the back emf diode, it is specific to my controller and should really be part of it. I used twin screened cable with the braid grounded at the controller end and left unconnected at the filter end. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.47402462363243103, "perplexity": 1094.184623112509}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-22/segments/1495463612553.95/warc/CC-MAIN-20170529203855-20170529223855-00410.warc.gz"} |
https://artofproblemsolving.com/wiki/index.php?title=Ceva%27s_Theorem&diff=next&oldid=18121 | Difference between revisions of "Ceva's Theorem"
Ceva's Theorem is a criterion for the concurrence of cevians in a triangle.
Statement
Let be a triangle, and let be points on lines , respectively. Lines concur iff (if and only if)
,
where lengths are directed.
(Note that the cevians do not necessarily lie within the triangle, although they do in this diagram.)
Proof
We will use the notation to denote the area of a triangle with vertices .
First, suppose meet at a point . We note that triangles have the same altitude to line , but bases and . It follows that . The same is true for triangles , so
.
Similarly, and , so
.
Now, suppose satisfy Ceva's criterion, and suppose intersect at . Suppose the line intersects line at . We have proven that must satisfy Ceva's criterion. This means that
,
so
,
and line concurrs with and .
Trigonometric Form
The trigonometric form of Ceva's Theorem (Trig Ceva) states that cevians concur if and only if
Proof
First, suppose concur at a point . We note that
,
and similarly,
.
It follows that
.
Here, sign is irrelevant, as we may interpret the sines of directed angles mod to be either positive or negative.
The converse follows by an argument almost identical to that used for the first form of Ceva's Theorem.
Examples
1. Suppose AB, AC, and BC have lengths 13, 14, and 15. If and , find BD and DC.
If and , then , and . From this, we find and .
2. The concurrence of the altitudes of a triangle at the orthocenter and the concurrence of the perpendicual bisectors of a triangle at the circumcenter can both be proven by Ceva's Theorem (the latter is a little harder). Furthermore, the existance of the centroid can be shown by Ceva, and the existance of the incenter can be shown using trig Ceva. However, there are more elegant methods for proving each of these results, and in any case, any result obtained by classic Ceva's Theorem can be proven using ratios of areas.
3. The existance of isotonic conjugates can be shown by classic Ceva, and the existance of isogonal conjugates can be shown by trig Ceva. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9836283326148987, "perplexity": 679.2083853727665}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107867463.6/warc/CC-MAIN-20201019232613-20201020022613-00434.warc.gz"} |
https://www.scm.com/highlights/surface-activation-of-mao/ | # Surface activation of MAO
In a recent study, the interaction of various methylaluminoxane (MAO) models on the (110) MgCl2 surface were studied with dispersion corrected DFT (revPBE-D3) in ADF. MAO activates the metallocene catalyst, but the structure(s) of MAO are unknown and depend on the reaction conditions (see also this highlight).
The use of a support affects the equilibrium between species that could potentially be active in polymerization and those that are dormant. The work was carried out to get a better understanding of how the support lowers the Al:catalyst ratio necessary for good polymer activities. As the calculations in this paper show, the active state of MAO is stabilized by the (110) MgCl2 surface. An ETS-NOCV analyses revealed that the active MAO species interacted with the surface via surface to adsorbate donation (Cl to Al) as well as via sizable interactions involving charge donation to the surface Mg atoms from MAO methyl groups or O atoms. Insight in the bonding interactions of the surface, the catalyst and co-catalyst can help to understand the complexities of the heterogeneously catalyzed olefin polymerization reaction.
Bonding interactions between MAO and MgCl2 support | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.822845458984375, "perplexity": 4041.7581277762733}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446710155.67/warc/CC-MAIN-20221127005113-20221127035113-00429.warc.gz"} |
http://math.stackexchange.com/questions/9960/complex-inequality-up-1u-vp-1v-leq-c-p-u-vup-1vp-1 | # Complex inequality $||u|^{p-1}u - |v|^{p-1}v|\leq c_p |u-v|(|u|^{p-1}+|v|^{p-1})$
How does one show for complex numbers u and v, and for p>1 that
\begin{equation*} ||u|^{p-1}u - |v|^{p-1}v|\leq c_p |u-v|(|u|^{p-1}+|v|^{p-1}), \end{equation*}
where $c_p$ is some constant dependent on p. My intuition is to use some version of the mean value theorem with $F(u) = |u|^{p-1}u$, but I'm not sure how to make this work for complex-valued functions. Plus there seems to be an issue with the fact that $F$ may not smooth near the origin.
For context, this shows up in Terry Tao's book Nonlinear Dispersive Equations: Local and Global Analysis on pg. 136, where it is stated without proof as an "elementary estimate".
-
Suppose without loss of generality that $|u| \geq |v| > 0$. Then you can divide the equation through by $|v|^p$ and your task it to prove $||w|^{p-1}w - 1| \leq c_p|w - 1|(|w|^{p-1} + 1)$, where $w = u/v$. Note that $$||w|^{p-1}w - 1| = ||w|^{p-1}w - |w|^{p-1} + |w|^{p-1} - 1|$$ $$\leq ||w|^{p-1}w - |w|^{p-1}| + ||w|^{p-1} - 1|$$ Note the first term is $|w|^{p-1}|w - 1|$ is automatically bounded by your right hand side. So you're left trying to show that $||w|^{p-1} - 1|$ is bounded by your right hand side. For this it suffices to show that $$||w|^{p-1} - 1| \leq c_p||w| - 1|| (|w|^{p-1} + 1)$$ Since $|w| \geq 1$ by the assumption that $|u| \geq |v|$, it suffices to show that for all real $r \geq 1$ one has $$r^{p-1} - 1 \leq c_p(r - 1)(r^{p-1} + 1)$$ Now use the mean value theorem as you originally wanted to.
Without loss, you can assume $|u|\le|v|$ and replace $u$ by $uv$ to reduce the problem to the situation $v=1$ and $|u|\le1$. Unless you need $c_p$ explicitly, then it's clear, yes? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9767878651618958, "perplexity": 86.04309301102441}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-30/segments/1469257824217.36/warc/CC-MAIN-20160723071024-00062-ip-10-185-27-174.ec2.internal.warc.gz"} |
https://scipost.org/SciPostPhys.3.5.034 | ## Entanglement Entropy in Lifshitz Theories
Temple He, Javier M. Magan, Stefan Vandoren
SciPost Phys. 3, 034 (2017) · published 16 November 2017
### Abstract
We discuss and compute entanglement entropy (EE) in (1+1)-dimensional free Lifshitz scalar field theories with arbitrary dynamical exponents. We consider both the subinterval and periodic sublattices in the discretized theory as subsystems. In both cases, we are able to analytically demonstrate that the EE grows linearly as a function of the dynamical exponent. Furthermore, for the subinterval case, we determine that as the dynamical exponent increases, there is a crossover from an area law to a volume law. Lastly, we deform Lifshitz field theories with certain relevant operators and show that the EE decreases from the ultraviolet to the infrared fixed point, giving evidence for a possible $c$-theorem for deformed Lifshitz theories.
### Ontology / Topics
See full Ontology or Topics database.
### Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.
Funders for the research work leading to this publication | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8784164786338806, "perplexity": 2674.973061034539}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320300253.51/warc/CC-MAIN-20220117000754-20220117030754-00682.warc.gz"} |
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# Set X consists of 100 numbers. The average (arithmetic mean)
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Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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Updated on: 24 Sep 2015, 02:52
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Set X consists of 100 numbers. The average (arithmetic mean) of set X is 10, and the standard deviation is 4.6. Which of the following two numbers, when added to set X, will decrease the set’s standard deviation by the greatest amount?
A. -100 and -100
B. -10 and -10
C. 0 and 0
D. 0 and 20
E. 10 and 10
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Originally posted by Hussain15 on 30 May 2010, 05:49.
Last edited by Bunuel on 24 Sep 2015, 02:52, edited 1 time in total.
Renamed the topic, edited the question and added the OA.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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04 Jun 2010, 05:49
4
3
Hussain15 wrote:
Hussain15 wrote:
I have another doubt:
If we will add 10 & 10 to set X, then the arithematic mean will not change i.e it will still be 10. Hence the standar deviation will not change & will remain the same. But our requirement is that SD will decrease in maximum.
What am I missing here?
I think the red portion in my statement above is not correct. SD will come down.
"Standard deviation shows how much variation there is from the mean. A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values."
So when we add numbers, which are far from the mean we are stretching the set making SD bigger and when we add numbers which are close to the mean we are shrinking the set making SD smaller.
According to the above adding two numbers which are closest to the mean will shrink the set most, thus decreasing SD by the greatest amount.
Closest to the mean are 10 and 10 (actually these numbers equal to the mean) thus adding them will shrink the set most, thus decreasing SD by the greatest amount.
Answer: E.
amitjash wrote:
I have a doubt for this explaination.
The question says "will decrease the set’s standard deviation by the GREATEST amount" Now if SD is +ve then adding a negetive number will reduce the standard deviation correct?? and if SD is -ve then adding the positive number will reduce the standard deviation. the value of the added will depend on the number of data given.
Please correct me if i am wrong.
SD is always $$\geq{0}$$. SD is 0 only when the list contains all identical elements (or which is same only 1 element).
For more on this issue please check Standard Deviation chapter of Math Book (link in my signature) and the following two topics for practice:
ps-questions-about-standard-deviation-85897.html
ds-questions-about-standard-deviation-85896.html
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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30 May 2010, 06:22
4
Hussain15 wrote:
Set X consists of 100 numbers. The average (arithmetic mean) of set X is 10, and the standard deviation is 4.6. Which of the following two numbers, when added to set X, will decrease the set’s standard deviation by the greatest amount?
A. -100 & -100
B. -10 & -10
C. 0 & 0
D. 0 & 20
E. 10 & 10
Answer E
Standard Deviation is deviation from the mean. If all the numbers in a set are equal to mean, then the standard deviation will be zero.
Therefore, in the given set with mean of 10, if we add 10 & 10, then the standard deviation will reduce. All other numbers will increase the standard deviation.
Please note that B is not the answer. Mean is +10 and, therefore, -10 is 20 points away from +10 (its not equal to the mean). Therefore, -10 will increase the standard deviation of the given set.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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02 Jun 2010, 16:48
1
Clearly E, as the mean of the set is 10. Adding the mean as an extra value in the set will decrease the standard deviation.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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04 Jun 2010, 02:41
I have a doubt for this explaination.
The question says "will decrease the set’s standard deviation by the GREATEST amount" Now if SD is +ve then adding a negetive number will reduce the standard deviation correct?? and if SD is -ve then adding the positive number will reduce the standard deviation. the value of the added will depend on the number of data given.
Please correct me if i am wrong.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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04 Jun 2010, 05:04
I have another doubt:
If we will add 10 & 10 to set X, then the arithematic mean will not change i.e it will still be 10. Hence the standar deviation will not change & will remain the same. But our requirement is that SD will decrease in maximum.
What am I missing here?
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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04 Jun 2010, 05:14
Hussain15 wrote:
I have another doubt:
If we will add 10 & 10 to set X, then the arithematic mean will not change i.e it will still be 10. Hence the standar deviation will not change & will remain the same. But our requirement is that SD will decrease in maximum.
What am I missing here?
I think the red portion in my statement above is not correct. SD will come down.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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04 Jun 2010, 05:43
Yes, this part is incorrect.
There will be no change in the average if you add (10, 10), but the difference will be zero, when we calculate for SD. So, SD will be <4.6.
E is correct, which brings the miminum sum after subtracting and squaring the differences for SD calculations.
Hussain15 wrote:
Hussain15 wrote:
I have another doubt:
If we will add 10 & 10 to set X, then the arithematic mean will not change i.e it will still be 10. Hence the standar deviation will not change & will remain the same. But our requirement is that SD will decrease in maximum.
What am I missing here?
I think the red portion in my statement above is not correct. SD will come down.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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04 Jun 2010, 09:48
1
You can prove it yourself with a couple quick calculations. Try calculating the SD for the set
{1,2,3}
and then calculate it for the set
{1,2,2,3}
Notice how it decreases.
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Re: Standard Devi [#permalink]
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24 Oct 2010, 13:10
5
1
shrive555 wrote:
Set X consists of 100 numbers. The average (arithmetic mean) of set X is 10, and the standard deviation is 4.6. Which of the following two numbers, when added to set X, will decrease the set’s standard deviation by the greatest amount?
A. -100 and -100
B. -10 and -10
C. 0 and 0
D. 0 and 20
E. 10 and 10
"Standard deviation shows how much variation there is from the mean. A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values."
So when we add numbers, which are far from the mean we are stretching the set making SD bigger and when we add numbers which are close to the mean we are shrinking the set making SD smaller.
According to the above adding two numbers which are closest to the mean will shrink the set most, thus decreasing SD by the greatest amount.
Closest to the mean are 10 and 10 (actually these numbers equal to the mean) thus adding them will shrink the set most, thus decreasing SD by the greatest amount.
Answer: E.
For more on this issue please check Standard Deviation chapter of Math Book (link in my signature) and the following two topics for practice:
ps-questions-about-standard-deviation-85897.html
ds-questions-about-standard-deviation-85896.html
Hope it helps.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) [#permalink]
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08 Dec 2013, 23:33
Bunuel wrote:
gmatgambler wrote:
Set X consists of 100 numbers. The average (arithmetic mean) of set X is 10, and the standard deviation is 4.6. Which of the following two numbers, when added to set X, will decrease the set’s standard deviation by the greatest amount?
A)-100 and -100
B)-10 and -10
C)0 and 0
D)0 and 20
E)10 and 10
Merging similar topics. Please refer to the solutions above.
Theory on Statistics and Sets problems: math-standard-deviation-87905.html
All DS Statistics and Sets problems to practice: search.php?search_id=tag&tag_id=34
All PS Statistics and Sets problems to practice: search.php?search_id=tag&tag_id=55
Similar questions to practice:
a-certain-list-has-an-average-of-6-and-a-standard-deviation-97473.html
a-certain-list-of-100-data-has-an-average-arithmetic-mean-87743.html
a-certain-list-of-200-test-scores-has-an-average-131448.html
new-ds-set-150653-60.html#p1211907
ps-questions-about-standard-deviation-85897.html
lately-many-questions-were-asked-about-the-standard-85896.html
Hope this helps.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) [#permalink]
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14 Jun 2014, 04:51
How I think about problems associated with means and standard deviations is with scattered data points. Since this question is regarding standard deviations (and how to reduce it), a quantity calculated to indicate the extent of deviation for the group -- the greater the deviation from the mean the greater the standard deviation. Therefore what data points will help to reduce deviation from the mean of set X [10]. If you add two points with the value of the mean their deviation will be 0, which is the smallest deviation you can add to the set of numbers.
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Re: Set X consists of 100 numbers. The average (arithmetic mean) of set X [#permalink]
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24 Sep 2015, 01:33
i reviewed math of Gmat club and found that 10,10 will not decrease the SD
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Re: Set X consists of 100 numbers. The average (arithmetic mean) [#permalink]
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25 Dec 2015, 12:01
HIgh SD = Wide distribution of data in the set
Low SD = Closely associated data in the set
The intention is to reduce the SD
That implies the newer entrants into the set need to near the mean
Option A would Increase the SD the most
Option E would not affect as much.
Hence E
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Re: Set X consists of 100 numbers. The average (arithmetic mean) [#permalink]
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10 Apr 2018, 16:06
Hussain15 wrote:
Set X consists of 100 numbers. The average (arithmetic mean) of set X is 10, and the standard deviation is 4.6. Which of the following two numbers, when added to set X, will decrease the set’s standard deviation by the greatest amount?
A. -100 and -100
B. -10 and -10
C. 0 and 0
D. 0 and 20
E. 10 and 10
The standard deviation is a measure of the spread of data values around the mean. If data values are close to the mean, the standard deviation is small, and if data values are further away from the mean, the standard deviation is larger.
Thus, in order to decrease the standard deviation, we want to find two values that are as close to the mean as possible. Since the mean is 10, the two values of 10 and 10 will decrease the standard deviation by the greatest amount.
Answer: E
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Re: Set X consists of 100 numbers. The average (arithmetic mean) [#permalink]
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21 Apr 2018, 22:03
niks18 Bunuel chetan2u
Quote:
Set X consists of 100 numbers. The average (arithmetic mean) of set X is 10, and the standard deviation is 4.6. Which of the following two numbers, when added to set X, will decrease the set’s standard deviation by the greatest amount?
A. -100 and -100
B. -10 and -10
C. 0 and 0
D. 0 and 20
E. 10 and 10
If one of the answer option is -10 and 10, will it mean same as (C)?
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Re: Set X consists of 100 numbers. The average (arithmetic mean) [#permalink]
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21 Apr 2018, 23:04
adkikani wrote:
niks18 Bunuel chetan2u
Quote:
Set X consists of 100 numbers. The average (arithmetic mean) of set X is 10, and the standard deviation is 4.6. Which of the following two numbers, when added to set X, will decrease the set’s standard deviation by the greatest amount?
A. -100 and -100
B. -10 and -10
C. 0 and 0
D. 0 and 20
E. 10 and 10
If one of the answer option is -10 and 10, will it mean same as (C)?
hi adkikani
Can you elaborate your query? If Option is not present and instead of Option E, your option of -10 and 10 is given then in my opinion none of the answer choice will decease the SD but will increase the SD. So the question will become irrelevant.
Between Option C i.e. 0 & 0 and your option -10 & 10, 0 & 0 will have a less incremental impact on SD than -10 & 10 because both 0 & 0 and -10 & 10 will only reduce the average of the set but when you subtract each element of the set with the reduced average and then square it to get the variance, then -10 & 10 will give you higher variance than 0 & 0, resulting in higher SD
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Re: Set X consists of 100 numbers. The average (arithmetic mean) [#permalink]
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03 Dec 2018, 05:56
Official Explanation:
Standard deviation is a tricky subject. Here’s a GMAT blog that explains absolutely everything you need to know about the standard deviation.
First we have to understand what the mean is. The mean is just the plain old average --- add up all the terms on the list, and divide by the number of terms on the list. Adding -100 and -100 would lower the mean the most, but that’s not what the question is asking.
The standard deviation is something much more complicated. There's a technical definition, which I explain in that GMAT blog, but the more informal definition is fine for this problem.
The informal definition --- standard deviation is sort of an average of the deviations from the mean. You see, every term has its own distance from the mean, and we call that a “deviation from the mean” ---- for these purposes, we count it as positive whether it’s greater than or less than the mean.
In this problem, the mean = 10. A value of 13 would have a deviation from the mean of 3. A value of 7 would also have a deviation from the mean of 3. Each of those terms, 13 and 7, are a distance of 3 from the mean, so in terms of the standard deviation, they contribute the same thing. Very high or very low numbers, far away from the mean, would have large deviations from the mean. We find the deviation from the mean of every number on the list --- all 100 numbers in this problem ---- and the standard deviation is sort of an average of all 100 of those deviations from the mean. (Again, this is not the precise definition, it’s not a strict average, but for this problem it’s close enough.)
The question gives a numerical value for the standard deviation, 4.6, but that's just a distractor. We don't need that.
The question asks us to add two numbers that lower the standard deviation the most. Well, the standard deviation is a kind of average, and if we want to lower any average, we have to add new terms that make contributions as small as possible. What's the smallest possible deviation a number could have from the mean? If we added a new term with a value of 10, that term equals the mean, so its deviation from the mean—its distance from the mean—is zero. If the new term is anything above or below 10, it will have a deviation from the mean greater than zero. Therefore, the lowest possible deviation from the mean a term can have is zero, and this is possible only if the term equals the mean of 10. Thus, if we two terms, both equal to the mean, we will be adding two terms with the lowest possible deviation from the mean, and that will lower the standard deviation, the average across all deviations from the mean, as much as possible.
Answer = E
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Set X consists of 100 numbers. The average (arithmetic mean) [#permalink]
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07 Dec 2018, 03:24
Hussain15 wrote:
Set X consists of 100 numbers. The average (arithmetic mean) of set X is 10, and the standard deviation is 4.6. Which of the following two numbers, when added to set X, will decrease the set’s standard deviation by the greatest amount?
A. -100 and -100
B. -10 and -10
C. 0 and 0
D. 0 and 20
E. 10 and 10
if the question had asked "...will decrease the set’s standard deviation by the LEAST amount .
the answer would be (0,20) & (0,0) & (-10,10) right?
cause : -100, -100 will make numerator very large , thus increasing the SD.
only (0,0) & (0,20) & (-10,-10) will add 100,100 to the numerator ( least among all)
for increase by greatest , answer would be -100,-100
for increase by least , answer = cant say
Set X consists of 100 numbers. The average (arithmetic mean) &nbs [#permalink] 07 Dec 2018, 03:24
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# Set X consists of 100 numbers. The average (arithmetic mean)
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Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8627052903175354, "perplexity": 1654.4822391536102}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-04/segments/1547583659944.3/warc/CC-MAIN-20190118070121-20190118092121-00471.warc.gz"} |
https://astronomy.stackexchange.com/questions/13098/should-this-photo-of-the-suns-surface-actually-be-white | # Should this photo of the sun's surface actually be white?
If I'm told correctly (eg. What Color is the Sun?) that the sun is actually white, should the photo on that page actually be white too? Is it just doctored to meet peoples expectations?:
Likewise for all the red photo's in a Google image search for "The Sun's surface".
• White? I thought sun was Asian.....I mean yellow!! – Dumbledore Jan 22 '16 at 1:41
• Actually, according to QI (a UK TV program), the sun is a black body because it reflects no light - it only emits it. Fancy that! – Richard Heyes Jan 22 '16 at 10:06
• Thanks for sharing that. Good to know! Now, everything is contradicting with what I learnt in the 2nd grade. – Dumbledore Jan 22 '16 at 13:57
The term "color" is a label that humans have assigned to denote the ratio between the intensity at various wavelengths in the three different wavelength bands, or regions, that the human eye is able to perceive. These bands are centered roughly at 430, 545, and 570 nm, but are quite broad and even overlap:
Human cone response, normalized to the same height. In reality, the response of the blue cones is significantly smaller, and the green is somewhat larger (from Wikipedia).
If an object emits light only at, say, 450 nm, the ratio is roughly 0.1:0.2:1 (in the order R:G:B); it then looks a special way to us, and we call it "blue", or maybe "violet". If it emits at 550 nm, or 650 nm, we call it "green" or "red". An object that emits light in a more continuous spectrum that covers the region 500–600 nm, we'd name something like orange-/brown-/olive-ish, depending on the exact spectrum.
The Sun emits photons at all wavelengths, but not in an equal amount at all wavelengths. The particular ratios between the three bands that we can see, we have labeled "white". However, when the Sun's light enters our atmosphere, some of the light is absorbed, especially at the blue wavelength. Filtering out the blue results in a spectrum that looks more orange to us. The figure below shows the Sun's "true" spectrum (in yellow), and the spectrum seen from the surface of Earth (in red):
The Sun's spectrum measured outside our atmosphere (yellow) and at sea level (red) (modified image from Wikipedia, with data from Global Warming Art).
Sometimes we want to observe the Sun in a wavelength region that is invisible to humans, for instance in UV or X-rays. This can be done with a telescope and a detector that is sensitive to light in that particular region, but in order for us to see it, we represent the image with a color that we can see. The image in the top of the link you provide is taken with the European spacecraft SOHO's instrument EIT at 19.5 nm, which we call "extreme UV", bordering on soft X-rays. Since this is invisible to humans, they arbitrarily chose to represent it using green. They might as well have chosen pink or brown.
The Sun in Extreme UV, during a particularly violent solar flare (from the SOHO gallery).
Several of the photos in your second link are images taken by the Japanese space telescope Hinode, which observes both in the optical (i.e. visible by humans), X-rays, and far UV. If these are shown in orange, again it's just to make them visible to us, and you may say that they have been "doctored to meet our expectation". In this way, I like better when they choose a color such as all green, so we know it's "false color".
• This is your answer, lela, so I'm not going to edit it. The effective temperature of the Sun is 5777 kelvins (or 5778 kelvins, depending on who one reads), not 5525 kelvin. That image at wikipedia is unsourced and is, as far as I can tell, invented. Here's a link to a much better image, also at wikipedia: commons.wikimedia.org/wiki/… . – David Hammen Jan 8 '16 at 20:28
• @DavidHammen: Thanks, I don't know where I had my head. The picture you link to is good for showing $T_\mathrm{eff}$, but doesn't show the spectrum of the Sun at sea level. I'll just remove the part about the Planck fit, since it doesn't really have anything to do with the question. – pela Jan 9 '16 at 15:21
The credit for that green image includes SOHO. SOHO routinely uses that green for images of the sun in hard X-Rays at 19.5 nanometers.
Visible light only goes down to about 390nm for extreme violet.
The picture looks like it's taken in hard X-ray wavelengths.
••• Later: Sorry, I meant hard UV/soft X-Rays. Don't know where my head was when I wrote this answer. SOHO's still the green pix in hard UV source though.
• Thanks for prompting me to investigate this properly. It turns out the image is actually UV (19.5 nm is considered "extreme UV", but on the border of "soft X-ray"). – pela Jan 7 '16 at 11:10
• @pela You're right, hard UV. I've added a bit to the answer so people aren't left with the wrong impression. – Wayfaring Stranger Jan 7 '16 at 16:25
Unobscured sunlight is white by definition.
You may find this article interesting, The Yellow Sun Paradox, as to why we consider the sun yellow in casual observation.
I would add another possible physiological explanation to the three suggested in this article: The retina's blue cones saturate at lower illumination than the red and green ones, which creates a deficit of blue signal to the optical nerve under heavy stimulation, resulting in a perception of red + green = yellow.
Conversely the sensitivity of the blue cones is why very dim objects such as faint stars in the night sky usually seem to be blue.
Now, as to the images. There are three possible reasons for an image to be yellow or orange. Perhaps, as a nod to expectations, it has been colorized. Possibly it is a false color image that maps a real but non-visible spectrum (radio, microwave, IR, UV, or X-ray) onto the visible spectrum.
But most of the images you present us with in your google search are using a technique sometimes called flame gradation, where a gray-scale (black→gray→white) is mapped on to a flame-scale:
black → [purple?] → brown → red → orange → gold → yellow → white → [cyan?]
to allow a much greater range of gradation in intensity to be perceived. It also suggests rather naturally a cold→cool→warm→hot gradation.
• I wouldn't put this question into "astronomy stack exchange" because it is more about biology/physiology. However, you seem pretty knowledgeable in this area. First, I must make the obvious statement that what we see as colors is actually the brain's "interpretation" of the information received by the retina's cones and transmitted by the optical nerve. My question is: If I moved to a planet orbiting a red star (say Gliese 581) where the light spectrum is different, would my brain eventually interpret colors differently? Easy experiment using college students. Ha ha. – Jack R. Woods Jan 18 '16 at 18:55 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5149588584899902, "perplexity": 1177.1683175156497}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400198652.6/warc/CC-MAIN-20200920192131-20200920222131-00422.warc.gz"} |
https://www.physicsforums.com/threads/coulombs-law.87298/ | # Coulomb's law
1. Sep 2, 2005
### mystry4
Can someone explain this law to me in simple terms? I know that it is the electrostatic force between 2 charged objects in relation to the quantity and inversly related to the square of distance F=K q1 q2 / d^2 ..but what if you have atoms that are spearated by a certain distance and have extra electrons? What happens to the force if you double the charges?
Thank you.
2. Sep 2, 2005
### codyg1985
$$q_1$$ and $$q_2$$ represents the net charge of the atoms. For example, if you have $$Fe^2^+$$ and $$Cl^-$$, then $$q_1$$ and $$q_2$$ would be 2 and 1, respectively. The second number would be positive because it accepts a negative charge by default, making the answer a positive number.
3. Sep 3, 2005
### mystry4
so, the formula I typed above is correct and could be used with 2 oxygen atoms, 3 cm apart and each have 2 extra electrons ? Wouldn't I get a -2 charge?
(-2)(-2) / 3cm ??
4. Sep 3, 2005
### teclo
well, atoms for the most part are neutral. if you had two oxygen atoms that somehow gained electrons and each had a negative 2 charge that were placed next to eachother, they'd fly apart. negative * negative = positive -- repulsive force. negative * posative = negative -- attractive force.
doubling the charges of each one -- look at the equation.
F = (1/4*pi*epsilon-zero)*(q1)(q2)/d^2
say each charge is e (charge of an electron), and you double each one (2e), the magnitude of the force will increase by a factor of 4 (2*2).
dealing with atoms is a bit tricky, but to simplify it enough to say that there is a uniform sphereical charge distribution at the location of each ion would work. two negative ions placed near eachother in a closed system would accelerate away from eachother on the line that they create. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9510542750358582, "perplexity": 752.1726864861579}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988717954.1/warc/CC-MAIN-20161020183837-00564-ip-10-171-6-4.ec2.internal.warc.gz"} |
https://rd.springer.com/article/10.1007/s11012-016-0453-8 | Meccanica
, Volume 51, Issue 11, pp 2629–2645
# Nonlinear normal modes for damage detection
• Walter Lacarbonara
• Biagio Carboni
• Giuseppe Quaranta
Nonlinear Dynamics, Identification and Monitoring of Structures
## Abstract
The sensitivity of the nonlinear dynamic response to damage is investigated in simply supported beams by computing the nonlinear normal modes (NNMs) and exploiting the rich information they unfold about the nonlinear system behavior. Damage is introduced as a reduction of the flexural stiffness within a small segment of the beam span. The problem is formulated in a piece-wise fashion and analytically tackled by using the method of multiple scales to compute the NNMs and the backbone curves. The latter describe the frequency versus free oscillation amplitude for each mode and as such they represent the skeleton of the nonlinear frequency response around each beam modal frequency. The bending of the backbones is regulated by the so-called effective nonlinearity coefficients associated with each mode. The comparison between the damaged and undamaged beams shows a sensitivity of the effective nonlinearity coefficients higher than the sensitivity of the linear natural frequencies. Moreover, the nonlinear frequency trends unfold an interesting dependence of the nonlinear free response on the stiffness reduction at the damage site. Such dependence yields useful information about the damage position. An effective identification strategy for the damage position is proposed by computing the damage-induced discontinuities in the second derivative of the NNMs (i.e., first order estimate of the bending curvature), without resorting to a baseline model of the undamaged beam. This goal is achieved by computing a high order derivative of the Nadaraya–Watson kernel estimator, which is evaluated from a finite set of sampled beam deflections associated with each individual NNM. The results show that the second derivatives of higher NNMs are more sensitive to damage-induced discontinuities than the linear modal curvatures. The robustness against noise of the damage identification process is also discussed.
## Keywords
Backbone curves Damage detection Nonlinear normal modes Nadaraya–Watson kernel estimator Method of multiple scales Effective modal nonlinearity
## Notes
### Acknowledgments
The financial support of Lacarbonara and Carboni through a 2010–2011 MIUR (Italian Ministry of Education, University and Scientific Research) PRIN Grant and 2013 Sapienza Grant is gratefully acknowledged. The work of Quaranta is framed within the project DPC–ReLUIS, RS 4 “Osservatorio sismico delle strutture e monitoraggio”.
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http://ritaferreira.pt/ | ### Rita Ferreira
I am a Research Scientist in the Computer, Electrical and Mathematical Sciences & Engineering Division (CEMSE) of King Abdullah University of Science and Technology (KAUST). I am a member of Prof. Diogo Gomes's Group Non-linear PDEs & Viscosity Solutions Research Group @ KAUST.
### Research
My research interests lie in the areas of Partial Differential Equations, Continuum Mechanics, Calculus of Variations, and Homogenization. My research activities have been focused on asymptotic analysis using variational methods of dimension reduction and homogenization problems. Currently, I am also interested in the mathematical study of problems in imaging processing and in mean-field games.
### Publications
Papers published in scientific international journals with peer reviewing
• R. Ferreira and D. Gomes
Existence of Weak Solutions to Stationary Mean-Field Games through Variational Inequalities. To appear in SIAM J. Math. Anal., 2018.
• D. Evangelista, R. Ferreira, D. Gomes, L. Nurbekyan, V. Voskanyan
First-order, stationary mean-field games with congestion. Nonlinear Anal. 173, 37--74 (2018).
• R. Ferreira, I. Fonseca, and M.L. Mascarenhas
A chromaticity-brightness model for color images denoising in a Meyer's "u + v'' framework. Calc. Var. Partial Differential Equations 56, no. 5, Art. 140, 53 pp (2017).
• N. Almulla, R. Ferreira, and D. Gomes
Two numerical approaches to stationary mean-field games. Dyn. Games Appl. 7, no. 4, 657--682 (2017).
• N. Almayouf, E. Bachini, A. Chapouto, R. Ferreira, D. Gomes, D. Jordão, D. E. Junior, A. Karagulyan, J. Monasterio, L. Nurbekyan, G. Pagliar, M. Piccirilli, S. Pratapsi, M. Prazeres, J. Reis, A. Rodrigues, O. Romero, M. Sargsyan, T. Seneci, C. Song, K. Terai, R. Tomisaki, H. Velasco-Perez, V. Voskanyan, and X. Yang
Existence of positive solutions for an approximation of stationary mean-field games. Involve 10, no. 3, 473-493 (2017).
• R. Ferreira, M.L. Mascarenhas, and A. Piatnitski
Spectral analysis in thin tubes with axial heterogeneities. Port. Math. 72, no. 2, 247-266 (2015).
• R. Ferreira, C. Kreisbeck, and A.M. Ribeiro
Characterization of polynomials and higher-order Sobolev spaces in terms of functionals involving difference quotients. Nonlinear Anal. 112, 199-214 (2015).
• R. Ferreira and D. Gomes
On the convergence of finite state mean-field games through Γ-convergence. J. Math. Anal. Appl. 418, no. 1, 211-230 (2014).
• R. Ferreira and I. Fonseca
Reiterated Homogenization in BV via Multiscale Convergence. SIAM J. Math. Anal. 44 , no. 3, 2053-2098 (2012).
• R. Ferreira and I. Fonseca
Characterization of the Multiscale Limit Associated with Bounded Sequences in BV. J. Convex Anal. 19, no. 2, 403-452 (2012).
• R. Ferreira, M.L. Mascarenhas, and A. Piatnitski
Spectral Analysis in a Thin Domain with Periodically Oscillating Characteristics. ESAIM Control Optim. Calc. Var. 18, no. 2, 427--451 (2012).
• R. Ferreira and M.L. Mascarenhas
Waves in a thin and periodically oscillating medium. C. R. Acad. Sci. Paris 346, no. 9-10, 579-584 (2008).
Papers submitted to scientific international journals with peer reviewing
• R. Ferreira, P. Hästö, and A. Ribeiro
Characterization of generalized Orlicz spaces. Submitted, 2016.
• R. Ferreira and E. Zappale
Bending-torsion moments in thin multi-structures in the context of nonlinear elasticity. Submitted, 2017.
• R. Ferreira, D. gomes, and T. Tada
Existence of weak solutions to first-order stationary mean-field games with Dirichlet conditions. Submitted, 2018.
Theses
• R. Ferreira
Spectral and Homogenization Problems. Ph.D. Thesis Dissertation, Carnegie Mellon University and Universidade Nova de Lisboa, Pittsburgh and Lisbon, 2011.
• R. Ferreira
Dimension Reduction in Nonlinear Elasticity via Gamma-Convergence. Master Thesis Dissertation, Faculdade de Ciências da Universidade de Lisboa (College of Science of the University of Lisbon), Lisbon, 2006. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 37, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.17469194531440735, "perplexity": 7963.327259852942}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267159160.59/warc/CC-MAIN-20180923055928-20180923080328-00148.warc.gz"} |
https://www.gradesaver.com/textbooks/math/algebra/intermediate-algebra-for-college-students-7th-edition/chapter-1-review-exercises-page-98/26 | ## Intermediate Algebra for College Students (7th Edition)
$-\dfrac{1}{10}$
Make the fractions similar using their LCD of 10 as denominator to obtain: $=-(\frac{3\cdot2}{5\cdot2}) - (-\frac{1\cdot5}{2\cdot5}) \\=-\frac{6}{10} - (-\frac{5}{10})$ RECALL: $a-b = a+(-b)$ Use the rule above to obtain: $=-\dfrac{6}{10} + \dfrac{5}{10} \\=\dfrac{-6+5}{10} \\=\dfrac{-1}{10}$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9647720456123352, "perplexity": 2276.671197793061}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221219197.89/warc/CC-MAIN-20180821230258-20180822010258-00311.warc.gz"} |
https://mitchellkember.com/sph4u/thin-film-interference.html | ## Thin-film interference
Thin-film interference occur when light waves reflect on the upper and lower boundaries of a thin film. This causes interference and it is responsible for the rainbow of colours that you see in soap bubbles and in puddles that have a thin layer of oil.
When the light strikes the thin film, it is both reflected and refracted. The refracted ray reflects off the bottom and refracts through the top to come out parallel with the original reflected ray:
When a wave reflects is in a fast medium and reflects on the interface to a slower medium, it inverts. This means the first wave inverts when it reflects, but the second wave does not. All other things being equal, they should be out of phase. Of course, other things aren’t equal because the second wave travels an extra distance. For small angles of incidence, this extra distance is about 2t where t is the thickness of the film.
There are three interesting cases for the thickness of the film. When t ≪ lambda, the extra distance is so small that the interference is destructive for all colours. When t=1//4lambda, the two waves are in phase. Why? If we don’t consider the extra distance, the waves are out of phase, meaning a phase delay of 1//2lambda; when we do consider it, we have 1//2lambda + 2t = lambda. Since they are in phase, they interfere constructively—all other colours (with different values of lambda) are blocked because the interference is destructive. When t=1//2lambda, the waves are out of phase and therefore destructive. This means that only that colour is blocked—the others are not.
phase delay type of interference The lambda colour other colours
t ≪ lambda small destructive blocked blocked
t = 1/4lambda lambda constructive reflected blocked
t = 1/2lambda 3/2lambda destructive blocked reflected | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8020318746566772, "perplexity": 971.188365024544}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-51/segments/1544376825349.51/warc/CC-MAIN-20181214022947-20181214044447-00343.warc.gz"} |
https://undergroundmathematics.org/vector-geometry/r7982/solution | Review question
# How fast do these connected particles move? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource
Ref: R7982
## Solution
The diagram shows two particles $A$ and $B$, connected by a light inextensible string which passes over a smooth fixed peg. The system is held with the string taut and with $A$ and $B$ each at a height of $\quantity{0.09}{m}$ above a fixed horizontal plane; it is then released from rest. When $B$ reaches the plane is becomes stationary.
Calculate
1. the tension in the string while both particles are in motion,
[Take $g$ to be $\quantity{10}{m\,s^{-2}}$.]
Let the acceleration of the particles be $a$, measured upwards on $A$ and downwards on $B$, and let the tension in the string be $T$. The following diagram shows the forces acting on the two particles.
Applying Newton’s second law, $F=ma$, to each of the particles and using $g=10$ we have \begin{align*} T-8 &= 0.8a \\ 12-T &= 1.2a. \end{align*}
Adding gives us $4=2a$, $a=2$. Substituting this into one of the equations gives $T=\quantity{9.6}{N}.$
Calculate
1. the speed of the particles when $B$ reaches the plane,
We know that $B$ starts at rest and travels $\quantity{0.09}{m}$. We know its acceleration and want to find its final velocity, so we use the equation of motion \begin{align*} v^2 &= u^2+2as. \\ v^2 &= 0+2\times2\times 0.09 = 0.36 \\ v &= 0.6 \end{align*}
The particles are moving at $\quantity{0.6}{m\,s^{-1}}$ when $B$ reaches the plane.
Calculate
1. the maximum height above the plane attained by $A$, assuming that $A$ does not reach the height of the fixed peg.
Assuming that neither the peg nor the string interfere with its motion, $A$ will now be under the influence only of gravity. We know its initial velocity is $\quantity{0.6}{m\,s^{-1}}$ upwards and its acceleration is $g$ downwards. We want to know its upwards displacement, so we’ll use the same equation of motion as before. \begin{align*} v^2 &= u^2+2as \\ 0 &= 0.6^2+2(-10)s \\ s &= \frac{0.36}{20} = 0.018 \end{align*}
This is how far it rises after the string becomes slack but this happens when $A$ is $2\times\quantity{0.09}{m}$ above the plane, so the maximum height above the plane is $2\times0.09+0.018=\quantity{0.198}{m}.$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9999110698699951, "perplexity": 370.5669533056185}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221217970.87/warc/CC-MAIN-20180821053629-20180821073629-00719.warc.gz"} |
https://infoscience.epfl.ch/record/206179 | ## Determination of Pt in digested animal plasma and tissues using High Resolution Inductively Coupled Plasma HR-ICP-MS.
Determination of Pt in digested animal plasma and tissues using High Resolution Inductively Coupled Plasma HR-ICP-MS. Samples were measured in Low Resolution LR mode considering Pt(194), Pt(195), Pt(196), and Pt(198). In order to minimize the matrix effect, calibration standards were prepared with samples of pig tissues free of Pt and treated in the same way as the samples to be analyzed containing platinum. Under theses experimental conditions Pt analytical determination results are reliable. Matrix effect and Pt determination using HR-ICP-MS will be discussed.
Presented at:
Platinum dosage results in digested plasma, CHUV Lausanne, June 20 2014
Year:
2014
Keywords:
Laboratories: | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8259323239326477, "perplexity": 9666.33126586263}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257647146.41/warc/CC-MAIN-20180319194922-20180319214922-00420.warc.gz"} |
https://math.stackexchange.com/questions/1745646/find-a-vector-v-such-that-v-mathbbct-cdot-v | # Find a vector $v$ such that $V=\mathbb{C}[T]\cdot v.$
Let $V=\mathbb{C}^2$ and let $\alpha:V\to V$ be the $\mathbb{C}$-linear map given by \begin{equation*} \begin{pmatrix} a\\ b \end{pmatrix} \longmapsto \begin{pmatrix} 2 & 3\\ -3 & 8 \end{pmatrix} \cdot \begin{pmatrix} a\\ b \end{pmatrix}. \end{equation*} Consider $V$ as a $\mathbb{C}[x]$-vector space with scalar multiplication $$\left(\sum_{i=0}^nc_ix^i\right)\cdot v\doteq\sum_{i=0}^nc_i\alpha^i(v),$$ where $\alpha^i$ denoted the $i$-times composition of $\alpha$. Find a vector $v\in V$ such that $V=\mathbb{C}[x]\cdot v.$
I'm not sure where to start. I suppose the problem is asking for a generator for $V$ as a $\mathbb{C}[x]$-vector space, but where I get confused is that $V=\mathbb{C}^2$ has rank $2$. How do I find a single generator? Any help/ hints are greatly appreciated.
• The polynomial ring $\;\Bbb C[x]\;$ is not a division ring, much less a field. I think the intention here is to give $\;V\;$ as module over $\;\Bbb C[x]\;$, not a vector space, which is a term usually reserved when working over fields or at least division rings. . – DonAntonio Apr 16 '16 at 22:39
• I believe the right-hand side term in the definition of your scalar multiplication should $\sum_{i=0}^nc_i\alpha^i(v)$. – Arnaud D. Apr 17 '16 at 9:27
• @ArnaudD. Yes, it should. My mistake. – Jfemdl Apr 18 '16 at 0:18
One way to do this is to take a vector $v$ such that $v$ and $\alpha(v)$ are linearly independent. Indeed, in this case they form a basis of $V$, so that for any $w\in V$ there exist unique $c_0,c_1\in \mathbb{C}$ such that $w=c_0v+c_1\alpha(v)$. Thus $$w=c_0v+c_1\alpha(v)=(c_0+c_1x)\cdot v\in \mathbb{C}[x]\cdot v,$$which shows that $V=\mathbb{C}[x]\cdot v$.
Now finding a vector $v$ such that $v$ and $\alpha(v)$ are linearly independent is quite easy; it suffices to take a vector that is not an eigenvector, so almost any vector will do the job. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.986409068107605, "perplexity": 68.42720899024326}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540529006.88/warc/CC-MAIN-20191210205200-20191210233200-00164.warc.gz"} |
https://nrich.maths.org/public/leg.php?code=32&cl=2&cldcmpid=6966 | # Search by Topic
#### Resources tagged with Multiplication & division similar to Counting Cogs:
Filter by: Content type:
Stage:
Challenge level:
### There are 163 results
Broad Topics > Calculations and Numerical Methods > Multiplication & division
### What's in the Box?
##### Stage: 2 Challenge Level:
This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?
### Factoring Factorials
##### Stage: 3 Challenge Level:
Find the highest power of 11 that will divide into 1000! exactly.
### Oh! Hidden Inside?
##### Stage: 3 Challenge Level:
Find the number which has 8 divisors, such that the product of the divisors is 331776.
### A First Product Sudoku
##### Stage: 3 Challenge Level:
Given the products of adjacent cells, can you complete this Sudoku?
### Remainders
##### Stage: 3 Challenge Level:
I'm thinking of a number. When my number is divided by 5 the remainder is 4. When my number is divided by 3 the remainder is 2. Can you find my number?
### Thirty Six Exactly
##### Stage: 3 Challenge Level:
The number 12 = 2^2 × 3 has 6 factors. What is the smallest natural number with exactly 36 factors?
### Multiplication Squares
##### Stage: 2 Challenge Level:
Can you work out the arrangement of the digits in the square so that the given products are correct? The numbers 1 - 9 may be used once and once only.
### Diggits
##### Stage: 3 Challenge Level:
Can you find what the last two digits of the number $4^{1999}$ are?
### Powerful Factorial
##### Stage: 3 Challenge Level:
6! = 6 x 5 x 4 x 3 x 2 x 1. The highest power of 2 that divides exactly into 6! is 4 since (6!) / (2^4 ) = 45. What is the highest power of two that divides exactly into 100!?
### Eminit
##### Stage: 3 Challenge Level:
The number 8888...88M9999...99 is divisible by 7 and it starts with the digit 8 repeated 50 times and ends with the digit 9 repeated 50 times. What is the value of the digit M?
### X Marks the Spot
##### Stage: 3 Challenge Level:
When the number x 1 x x x is multiplied by 417 this gives the answer 9 x x x 0 5 7. Find the missing digits, each of which is represented by an "x" .
### Ones Only
##### Stage: 3 Challenge Level:
Find the smallest whole number which, when mutiplied by 7, gives a product consisting entirely of ones.
### Missing Multipliers
##### Stage: 3 Challenge Level:
What is the smallest number of answers you need to reveal in order to work out the missing headers?
### Which Is Quicker?
##### Stage: 2 Challenge Level:
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
##### Stage: 3 Challenge Level:
If you take a three by three square on a 1-10 addition square and multiply the diagonally opposite numbers together, what is the difference between these products. Why?
### Tom's Number
##### Stage: 2 Challenge Level:
Work out Tom's number from the answers he gives his friend. He will only answer 'yes' or 'no'.
### What Two ...?
##### Stage: 2 Short Challenge Level:
56 406 is the product of two consecutive numbers. What are these two numbers?
### Multiples Sudoku
##### Stage: 3 Challenge Level:
Each clue in this Sudoku is the product of the two numbers in adjacent cells.
### The Remainders Game
##### Stage: 2 and 3 Challenge Level:
A game that tests your understanding of remainders.
### Divide it Out
##### Stage: 2 Challenge Level:
What is the lowest number which always leaves a remainder of 1 when divided by each of the numbers from 2 to 10?
### What Is Ziffle?
##### Stage: 2 Challenge Level:
Can you work out what a ziffle is on the planet Zargon?
### Two Many
##### Stage: 3 Challenge Level:
What is the least square number which commences with six two's?
### Curious Number
##### Stage: 2 Challenge Level:
Can you order the digits from 1-3 to make a number which is divisible by 3 so when the last digit is removed it becomes a 2-figure number divisible by 2, and so on?
### Division Rules
##### Stage: 2 Challenge Level:
This challenge encourages you to explore dividing a three-digit number by a single-digit number.
### Long Multiplication
##### Stage: 3 Challenge Level:
A 3 digit number is multiplied by a 2 digit number and the calculation is written out as shown with a digit in place of each of the *'s. Complete the whole multiplication sum.
### A Mixed-up Clock
##### Stage: 2 Challenge Level:
There is a clock-face where the numbers have become all mixed up. Can you find out where all the numbers have got to from these ten statements?
### Largest Number
##### Stage: 3 Challenge Level:
What is the largest number you can make using the three digits 2, 3 and 4 in any way you like, using any operations you like? You can only use each digit once.
### It Figures
##### Stage: 2 Challenge Level:
Suppose we allow ourselves to use three numbers less than 10 and multiply them together. How many different products can you find? How do you know you've got them all?
### Multiply Multiples 3
##### Stage: 2 Challenge Level:
Have a go at balancing this equation. Can you find different ways of doing it?
### Mystery Matrix
##### Stage: 2 Challenge Level:
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
### Multiply Multiples 1
##### Stage: 2 Challenge Level:
Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?
### Multiply Multiples 2
##### Stage: 2 Challenge Level:
Can you work out some different ways to balance this equation?
### Route Product
##### Stage: 2 Challenge Level:
Find the product of the numbers on the routes from A to B. Which route has the smallest product? Which the largest?
### Four Goodness Sake
##### Stage: 2 Challenge Level:
Use 4 four times with simple operations so that you get the answer 12. Can you make 15, 16 and 17 too?
### The Deca Tree
##### Stage: 2 Challenge Level:
Find out what a Deca Tree is and then work out how many leaves there will be after the woodcutter has cut off a trunk, a branch, a twig and a leaf.
### Zargon Glasses
##### Stage: 2 Challenge Level:
Zumf makes spectacles for the residents of the planet Zargon, who have either 3 eyes or 4 eyes. How many lenses will Zumf need to make all the different orders for 9 families?
### Zios and Zepts
##### Stage: 2 Challenge Level:
On the planet Vuv there are two sorts of creatures. The Zios have 3 legs and the Zepts have 7 legs. The great planetary explorer Nico counted 52 legs. How many Zios and how many Zepts were there?
### Book Codes
##### Stage: 2 Challenge Level:
Look on the back of any modern book and you will find an ISBN code. Take this code and calculate this sum in the way shown. Can you see what the answers always have in common?
### Sort Them Out (2)
##### Stage: 2 Challenge Level:
Can you each work out the number on your card? What do you notice? How could you sort the cards?
### Which Symbol?
##### Stage: 2 Challenge Level:
Choose a symbol to put into the number sentence.
### Forgot the Numbers
##### Stage: 2 Challenge Level:
On my calculator I divided one whole number by another whole number and got the answer 3.125. If the numbers are both under 50, what are they?
### Countdown
##### Stage: 2 and 3 Challenge Level:
Here is a chance to play a version of the classic Countdown Game.
### Multiplication Square Jigsaw
##### Stage: 2 Challenge Level:
Can you complete this jigsaw of the multiplication square?
### Number Tracks
##### Stage: 2 Challenge Level:
Ben’s class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
### As Easy as 1,2,3
##### Stage: 3 Challenge Level:
When I type a sequence of letters my calculator gives the product of all the numbers in the corresponding memories. What numbers should I store so that when I type 'ONE' it returns 1, and when I type. . . .
### How Much Did it Cost?
##### Stage: 2 Challenge Level:
Use your logical-thinking skills to deduce how much Dan's crisps and ice-cream cost altogether.
### Being Thoughtful - Primary Number
##### Stage: 1 and 2 Challenge Level:
Number problems at primary level that require careful consideration.
### Being Determined - Primary Number
##### Stage: 1 and 2 Challenge Level:
Number problems at primary level that may require determination.
### Rabbits in the Pen
##### Stage: 2 Challenge Level:
Using the statements, can you work out how many of each type of rabbit there are in these pens?
### Multiplication Series: Illustrating Number Properties with Arrays
##### Stage: 1 and 2
This article for teachers describes how modelling number properties involving multiplication using an array of objects not only allows children to represent their thinking with concrete materials,. . . . | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5308985114097595, "perplexity": 2408.595671663839}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320386.71/warc/CC-MAIN-20170625013851-20170625033851-00292.warc.gz"} |
https://collegemathteaching.wordpress.com/category/number-theory/ | # College Math Teaching
## September 23, 2016
### Carmichael Numbers: “not quite” primes…
Filed under: algebra, elementary number theory, number theory, recreational mathematics — collegemathteaching @ 9:49 pm
We had a fun mathematics seminar yesterday.
Andrew Shallue gave a talk about the Carmichael numbers and gave a glimpse into his research. Along the way he mentioned the work of another mathematician…one that I met during my ultramarathon/marathon walking adventures! Talk about a small world..
So, to kick start my brain cells, I’ll say a few words about these.
First of all, prime numbers are very important in encryption schemes and it is a great benefit to be able to find them. However, for very large numbers, it can be difficult to determine whether a number is prime or not.
So one can take short cuts in determining whether a number is *likely* prime or not: one can say “ok, prime numbers have property P and if this number doesn’t have property P, it is not a prime. But if it DOES have property P, we hare X percent sure that it really is a prime.
If this said property is relatively “easy” to implement (via a computer), we might be able to live with the small amount of errors that our test generates.
One such test is to see if this given number satisfies “Fermat’s Little Theorem” which is as follows:
Let $a$ be a positive integer and $p$ be a prime, and suppose $a \neq kp$, that is $a \neq 0 (mod p)$ Then $a^{p-1} = 1 (mod p)$
If you forgotten how this works, recall that $Z_p$ is a field if $p$ is a prime, so $a \in Z_p, a \neq 0 (mod p)$ means that the set $\{a, 2a, 3a, ...(p-1)a \}$ consists of $\{1, 2, 3, ...(p-1) \}$. So take the product $(a)(2a)(3a)...((p-1)a)) = 1(2)(3)..(p-1)a^{p-1} = 1(2)(3)...(p-1) (mod p)$. Now note that we are working in a field, so we can cancel the $(1)(2)...(p-1)$ factor on both sides to get $a^{p-1} = 1 (mod p)$.
So one way to check to see if a number $q$ might be a prime is to check all $a^{q-1}$ for all $a \leq q$ and see if $a^{q-1} = 1 mod q$.
Now this is NOT a perfect check; there are non-prime numbers for which $a^{q-1} = 1 mod q$ for all $a \leq q$; these are called the Carmichael numbers. The 3 smallest such numbers are 561, 41041 and 825265.
The talk was about much more than this, but this was interesting.
## February 5, 2016
### More fun with selective sums of divergent series
Just a reminder: if $\sum_{k=1}^{\infty} a_k$ is a series and $c_1, c_2, ...c_n ,,$ is some sequence consisting of 0’s and 1’s then a selective sum of the series is $\sum_{k=1}^{\infty} c_k a_k$. The selective sum concept is discussed in the MAA book Real Infinite Series (MAA Textbooks) by Bonar and Khoury (2006) and I was introduced to the concept by Ferdinands’s article Selective Sums of an Infinite Series in the June 2015 edition of Mathematics Magazine (Vol. 88, 179-185).
There is much of interest there, especially if one considers convergent series or alternating series.
This post will be about divergent series of positive terms for which $lim_{n \rightarrow \infty} a_n = 0$ and $a_{n+1} < a_n$ for all $n$.
The first fun result is this one: any selected $x > 0$ is a selective sum of such a series. The proof of this isn’t that bad. Since $lim_{n \rightarrow \infty} a_n = 0$ we can find a smallest $n$ such that $a_n \leq x$. Clearly if $a_n = x$ we are done: our selective sum has $c_n = 1$ and the rest of the $c_k = 0$.
If not, set $n_1 = n$ and note that because the series diverges, there is a largest $m_1$ so that $\sum_{k=n_1}^{m_1} a_k \leq x$. Now if $\sum_{k=n_1}^{m_1} a_k = x$ we are done, else let $\epsilon_1 = x - \sum_{k=n_1}^{m_1} a_k$ and note $\epsilon_1 < a_{m_1+1}$. Now because the $a_k$ tend to zero, there is some first $n_2$ so that $a_{n_2} \leq \epsilon_1$. If this is equality then the required sum is $a_{n_2} + \sum_{k=n_1}^{m_1} a_k$, else we can find the largest $m_2$ so that $\sum_{k=n_1}^{m_1} a_k + \sum_{k=n_2}^{m_2} a_k \leq x$
This procedure can be continued indefinitely. So if we label $\sum_{k=n_j}^{m_{j}} a_k = s_j$ we see that $s_1 + s_2 + ...s_{n} = t_{n}$ form an increasing, bounded sequence which converges to the least upper bound of its range, and it isn’t hard to see that the least upper bound is $x$ because $x-t_{n} =\epsilon_n < a_{m_n+1}$
So now that we can obtain any positive real number as the selective sum of such a series, what can we say about the set of all selective sums for which almost all of the $c_k = 0$ (that is, all but a finite number of the $c_k$ are zero).
Answer: the set of all such selective sums are dense in the real line, and this isn’t that hard to see, given our above construction. Let $(a,b)$ be any open interval in the real line and let $a < x < b$. Then one can find some $N$ such that for all $n > N$ we have $x - a_n > a$. Now consider our construction and choose $m$ large enough such that $x - t_m > x - a_n > a$. Then the $t_m$ represents the finite selected sum that lies in the interval $(a,b)$.
We can be even more specific if we now look at a specific series, such as the harmonic series $\sum_{k=1}^{\infty} \frac{1}{k}$. We know that the set of finite selected sums forms a dense subset of the real line. But it turns out that the set of select sums is the rationals. I’ll give a slightly different proof than one finds in Bonar and Khoury.
First we prove that every rational in $(0,1]$ is a finite select sum. Clearly 1 is a finite select sum. Otherwise: Given $\frac{p}{q}$ we can find the minimum $n$ so that $\frac{1}{n} \leq \frac{p}{q} < \frac{1}{n-1}$. If $\frac{p}{q} = \frac{1}{n}$ we are done. Otherwise: the strict inequality shows that $pn-p < q$ which means $pn-q < p$. Then note $\frac{p}{q} - \frac{1}{n} = \frac{pn-q}{qn}$ and this fraction has a strictly smaller numerator than $p$. So we can repeat our process with this new rational number. And this process must eventually terminate because the numerators generated from this process form a strictly decreasing sequence of positive integers. The process can only terminate when the new faction has a numerator of 1. Hence the original fraction is some sum of fractions with numerator 1.
Now if the rational number $r$ in question is greater than one, one finds $n_1$ so that $\sum^{n_1}_{k=1} \frac{1}{k} \leq r$ but $\sum^{n_1+1}_{k=1} \frac{1}{k} > r$. Then write $r-\sum^{n_1+1}_{k=1} \frac{1}{k}$ and note that its magnitude is less than $\frac{1}{n_1+1}$. We then use the procedure for numbers in $(0,1)$ noting that our starting point excludes the previously used terms of the harmonic series.
There is more we can do, but I’ll stop here for now.
## January 20, 2016
### Congratulations to the Central Missouri State Mathematics Department
Filed under: advanced mathematics, editorial, number theory — Tags: — collegemathteaching @ 10:43 pm
The largest known prime has been discovered by mathematicians at Central Missouri State University.
For what it is worth, it is: $2^{74,207,281} -1$.
Now if you want to be depressed, go to the Smithsonian Facebook page and read the comment. The Dunning-Kruger effect is real. Let’s just say that in our era, our phones are smarter than our people. 🙂
## October 25, 2013
### Why the sequence cos(n) diverges
We are in the sequences section of our Freshman calculus class. One of the homework problems was to find whether the sequence $a_n = cos(\frac{n}{2})$ converged or diverged. This sequence diverges, but it isn’t easy for a freshman to see.
I’ll discuss this problem and how one might go about explaining it to a motivated student. To make things a bit simpler, I’ll discuss the sequence $a_n = cos(n)$ instead.
Of course $cos(x)$ is periodic with a fundamental region $[0, 2\pi]$ so we will work with that region. Now we notice the following:
$n (mod 2 \pi)$ is a group with the usual operation of addition.
By $n (mod 2 \pi)$, I mean the set $n + k*2\pi$ where $k \in \{..-2, -1, 0, 1, 2, 3,...\}$; one can think of the analogue of modular arithmetic, or one might see the elements of the group $\{ r| r \in [0, 2 \pi), r = n - k 2\pi \}$.
Of course, to get additive inverses, we need to include the negative integers, but ultimately that won’t matter. Example: $1, 2, 3, 4, 5, 6$ are just equal to themselves $mod 2 \pi.$ $7 = 7 - 2\pi (mod 2\pi), 13 = 13 - 4 \pi (mod 2\pi)$, etc. So, I’ll denote the representative of $n (mod 2\pi)$ by $[n]$.
Now if $n \ne m$ then $[n] \ne [m]$; for if $[n]=[m]$ then there would be integers $j, k$ so that $n + j2\pi = m +k2\pi$ which would imply that $|m-n|$ is a multiple of $\pi$. Therefore there are an infinite number of $[n]$ in $[0, 2\pi]$ which means that the set $\{[n]\}$ has a limit point in the compact set $[0, 2\pi]$ which means that given any positive integer $m$ there is some interval of width $\frac{2\pi}{m}$ that contains two distinct $[i], [j]$ (say, $j$ greater than $i$.)
This means that $[j-i] \in (0, \frac{2\pi}{m})$ so there is some integers $k_2, k_3,$ so that $k_2[j-i] \in (\frac{2\pi}{m}, \frac{2*2\pi}{m}), k_3[j-i] \in (\frac{2*2\pi}{m}, \frac{3*2\pi}{m})$, etc. Therefore there is some multiple of $[j-i]$ in every interval of width $\frac{2\pi}{m}$. But $m$ was an arbitrary positive integer; this means that the $[n]$ are dense in $[0,2\pi]$. It follows that $cos([n]) = cos(n)$ is dense in $[-1,1]$ and hence $a_n = cos(n)$ cannot converge as a sequence.
Frankly, I think that this is a bit tough for most Freshman calculus classes (outside of, say those at MIT, Harvard, Cal Tech, etc.).
## May 16, 2013
### Big Breakthrough in Number Theory: progress toward the twin primes conjecture.
Filed under: advanced mathematics, number theory — Tags: , , — collegemathteaching @ 7:26 pm
It is a long standing conjecture in number theory that there exists an infinite number of twin primes: twin primes are prime integers that differ by 2.
Example: 3 and 5, 11 and 13, 17 and 19 are examples of twin prime pairs.
Very large twin primes have been found: $(2,003,663,613 \times 2^{2195,000}) - 1$ and $(2,003,663,613 \times 2^{2195,000}) + 1$.
But, up to now: We don’t know if this pairing “stops” at some point (is there a largest pair?)
In fact, up to recently, we had no statement of the following form: given a finite integer $M$ there exists an infinite number or pairs of primes $p, q$ such that $p - q \le M$ (assuming that $p$ is the greater of the pair).
Well, now we do. The Annals of Mathematics (the top ranked mathematics journal in the world) has accepted a paper that shows the infinite pairs statement is true, if $M = 70,000,000$:
The twin prime conjecture says that there is an infinite number of such twin pairs. Some attribute the conjecture to the Greek mathematician Euclid of Alexandria, which would make it one of the oldest open problems in mathematics.
The problem has eluded all attempts to find a solution so far. A major milestone was reached in 2005 when Goldston and two colleagues showed that there is an infinite number of prime pairs that differ by no more than 16. But there was a catch. “They were assuming a conjecture that no one knows how to prove,” says Dorian Goldfeld, a number theorist at Columbia University in New York.
The new result, from Yitang Zhang of the University of New Hampshire in Durham, finds that there are infinitely many pairs of primes that are less than 70 million units apart without relying on unproven conjectures. Although 70 million seems like a very large number, the existence of any finite bound, no matter how large, means that that the gaps between consecutive numbers don’t keep growing forever. The jump from 2 to 70 million is nothing compared with the jump from 70 million to infinity. “If this is right, I’m absolutely astounded,” says Goldfeld.
Zhang presented his research on 13 May to an audience of a few dozen at Harvard University in Cambridge, Massachusetts, and the fact that the work seems to use standard mathematical techniques led some to question whether Zhang could really have succeeded where others failed.
But a referee report from the Annals of Mathematics, to which Zhang submitted his paper, suggests he has. “The main results are of the first rank,” states the report, a copy of which Zhang provided to Nature. “The author has succeeded to prove a landmark theorem in the distribution of prime numbers. … We are very happy to strongly recommend acceptance of the paper for publication in the Annals.”
Hey, 70 million is a LOT less than “infinity”. 🙂
## January 17, 2013
### Enigma Machines: some of the elementary math
Note: this type of cipher is really an element of the group $S_{26}$, the symmetric group on 26 letters. Never allowing a letter to go to itself reduced the possibilites to products of cycles that covered all of the letters.
## August 8, 2011
### MathFest Day Three (Lexington 2011)
I left after the second large lecture and didn’t get a chance to blog about them before now.
But what I saw was very good.
The early lecture was by Lauren Ancel Meyers (Texas-Austin) on Mathematical Approaches to Infectious Disease and Control This is one of those talks where I wish I had access to the slides; they were very useful.
She started out by giving a brief review of the classical SIR model of the spread of a disease which uses the mass action principle (from science) that says that the rate of of change of those infected with a disease is proportional to the product of those who are susceptible to the disease and those who can transmit the disease: $\frac{dI}{dt}=\beta S I$. (this actually came from chemistry). Of course, those who are infected either recover or die; this action reduces the number infected. Of course, the number of susceptible also drop.
This leads to a system of differential equations. The basic reproduction number is significant:
$= R_0 = \frac{\beta S}{\nu + \delta}$ where $\nu$ is the recovery rate and $\delta$ is the death rate. Note: if $R_0 < 1$ then the disease will die off; if it is greater than 1 we have a pandemic. We can reduce this by reducing $S$ (vaccination or quarantine), increasing recovery or, yes, increasing the death rate (as we do with livestock; remember the massive poultry slaughters to stop the spread of flu).
Of course, this model assumes that the infected organisms contact others at random and have equal probabilities of spreading, that the virus doesn’t evolve, etc.
So this model had to be improved on; methods from percolation theory were developed.
So many factors had to be taken into account such as: how much vaccine is there to spread? How far along is the outbreak? (at first children get it; then adults). How severe is the consequences? (we don’t want the virus to evolve to a more dangerous, more resistant form).
Note that the graph model of transmission is dynamic; it can actually change with time.
Of special interest: one can recover the rate of infections of the various strains (and the strains vary from season to season) by looking at the number of times flu related words were searched for on Google. The graph overlap (search rate versus reported cases) was stunning; the only exception is when a scare occurred; then the word search rate lead the actual cases, but that happened only once (2009). Note also that predictions of what will happen get better with a shorter time window (not a surprise).
There was much more in the talk; for example the role of the location of the providers of vaccines was discussed (what is the optimal way to spread out the availability of a given vaccine?)
Manjur Bhargava, Lecture III
First, he noted that in the case where $f(x,y)$ was cubic, that there is always a rational change of variable to put the curve into the following form: $y^2 = x^3 + Ax + B$ where $A, B$ are integers that have the following property: if $p$ is any prime where $p^4$ divides $A$ then $p^6$ does NOT divide $B$. So this curve can be denoted as $E_{A,B}$.
Also, there are two “generic” cases of curves depending on whether the cubic in $x$ has only one real root or three real roots.
This is a catalog of elliptical algebraic curves of the form $y^2 = x^3 + ax + b$ taken from here. The everywhere smooth curves are considered; the ones with a disconnected graph are said to have “an egg”; those are the ones in which the cubic in $x$ has three real roots. In the connected case, the cubic has only one; remember that these are genus one curves; we are seeing a slice of a torus in 4-space (a space with two complex dimensions) in the plane.
Also recall that the rational points on the curve may be finite or infinite. It turns out that the rational points (both coordinates rational) have a group structure (this is called the “divisor class group” in algebraic geometry). This group has a structure that can be understood by a simple geometric construction in the plane, though checking that the operation is associative can be very tedious.
I’ll give a description of the group operation and provide an elementary example:
First, note that if $(x,y)$ is a point on an elliptical curve, then so is $(x, -y)$ (note: the $y^2$ on the left hand side of the defining equation). That is important. Also note that we will restrict ourselves to smooth curves (that have a well defined tangent line).
The elements of our group will be the rational points of the curve (if any?) along with the point at infinity. If $P = (x_1, y_1)$ I will denote $(x_1, -y_1) = P'$.
The operation: if $P, Q$ are rational points on the curve, construct the line $l$ with equation $y = m(x-x_1)+ y_1$ Substitute this into $y^2 = x^3 + Ax + B$ and note that we now have a cubic equation in $x$ that has two rational solutions; hence there must be a third rational solution $x_r$. Associated to that $x$ value is two $y$ values (possibly double if the $y$ value is zero). Call that point on the curve $R$ then define $P + Q = R'$ where $R'$ is the reflection of $R$ about the $x$ axis.
Note the following: that this operation commutes is immediate. If one adds a point to itself, one uses the tangent line as the line through two points; note that such a line might not hit the curve a third time. If such a line is vertical (parallel to the $y$ axis) the result is said to be “0” (the point at infinity); if the line is not vertical but still misses the rest of the curve, it is counted three times; that is: $P + P = P'$. Here are the situations:
Of course, $\infty$ is the group identity. Associativity is difficult to check directly (elementary algebra but very tedious; perhaps 3-4 pages of it?).
Since the group is Abelian, if the group is finite it must be isomorphic to $\oplus_{i = 1}^r Z_i \oplus \frac{Z}{n_1 Z} \oplus \frac{Z}{n_2 Z}....\frac{Z}{n_k Z}$ where the second part is the torsion part and the number of infinite cyclic factors is the rank. The rank turns out to be the geometric rank; that is, the minimum number of points required to obtain all of the rational points (infinite number) of the curve. Let $T$ be the torsion subgroup; Mazur proved that $|T|\le 16$.
Let’s look at an example of a subgroup of such a curve: let the curve be given by $y^2 = X^3 + 1$ It is easy to see that $(0,1), (0, -1), (2, 3), (2, -3), (-1, 0)$ are all rational points. Let’s see how these work: $(-1, 0) + (-1, 0) = 0$ so this point has order 2. But there is also some interesting behavior: note that $\frac{d}{dx} (y^2) = \frac{d}{dx}(x^3 + 1)$ which implies that $\frac{dy}{dx} = \frac{3x^2}{2y}$ So the tangent line through $(0, 1)$ and $(0, -1)$ are both horizontal; that means that both of these points have order 3. Note also that $(2, 3) + (2,3) = (0,1)$ as the tangent line runs through the point $(0, -1)$. Similarly $(2, 3) + (0, -1) = (2, -3)$ So, we can see that $(2,3), (2, -3)$ have order 6, $(0, 1), (0, -1)$ have order 3 and $(-1, 0)$ has order 2. So there is an isomorphism $\theta$ where $\theta(2,3) = 1, \theta(2,-3) = 5, \theta(0, 1) = 2, \theta(0, -1) = 4, \theta(-1, 0) = 3$ where the integers are mod 6.
So, we’ve shown a finite Abelian subgroup of the group of rationals of this curve. It turns out that these are the only rational points; here all we get is the torsion group. This curve has rank zero (not obvious).
Note: the group of rationals for $y^2 = x^3 + 2x + 3$ is isomorphic to $Z \oplus \frac{Z}{2Z}$ though this isn’t obvious.
The generator of the $Z$ term is $(3,6)$ and $(-1,0)$ generates the the torsion term.
History note Some of this was tackled by computers many years ago (Birch, Swinnerton-Dyer). Because computers were so limited in those days, the code had to be very efficient and therefore people had to do quite a bit of work prior to putting it into code; evidently this lead to progress. The speaker joked that such progress might not have been so quickly today due to better computers!
If one looks at $y^2 = x^3 + Ax + B mod p$ where $p$ is prime, we should have about $p$ points on the curve. So we’d expect that $\frac{N_p}{p} \approx 1$. If there are a lot of rational points on the curve, most of these points would correspond to $mod p$ points. So there is a conjecture by Birch, Swinnerton-Dyer:
$\prod_{p \le X} \frac{N_p}{p} \approx c (log(X))^r$ where $r$ is the rank.
Yes, this is hard; win one million US dollars if you prove it. 🙂
Back to the curves: there are ways of assigning “heights” to these curves; some include:
$H(E_{(A,B)}) = max(4|A|^3, 27B^2)$ or $\Delta(E_{(A,B)} -4A^3 - 27B^2$
Given this ordering, what are average sizes of ranks?
Katz-Sarnak: half have rank 0, half have rank 1. It was known that average ranks are bounded; previous results had the bound at 2.3, 2, 1.79, assuming that the Generalized Riemann Hypothesis and the Birch, Swinnerton-Dyer conjecture were asssumed.
The speaker and his students got some results without making these large assumptions:
Result 1: when $E/Q$ is ordered by height, the average rank is less than 1.
Result 2: A positive portion (10 percent, at least) have rank 0.
Result 3: at least 80 percent have rank 0 or 1.
Corollary: the BSD is true for a positive proportion of elliptic curves;
The speaker (with his student) proved results 1, 2, and 3 and then worked backwards on the existing “BSD true implies X” results to show that BSD was true for a positive proportion of the elliptic curves.
## August 6, 2011
### MathFest Day 2 (2011: Lexington, KY)
I went to the three “big” talks in the morning.
Dawn Lott’s talk was about applied mathematics and its relation to the study of brain aneurysms; in particular the aneurysm model was discussed (partial differential equations with a time coordinate and stresses in the radial, circumference and latitudinal directions were modeled).
There was also modeling of the clipping procedure (where the base of the aneurysm was clipped with a metal clip); various clipping strategies were investigated (straight across? diagonal?). One interesting aspect was that the model of the aneurysm was discussed; what shape gave the best results?
Note: this is one procedure that was being modeled:
Next, Bhargava gave his second talk (on rational points on algebraic curves)
It was excellent. In the previous lecture, we saw that a quadratic curve either has an infinite number of rational points or zero rational points. Things are different with a cubic curve.
For example, $y^2 = x^3 - 3x$ has exactly one rational point (namely (0,0) ) but $y^2 = x^3-2x$ has an infinite number! It turns out that the number of rational points an algebraic curve has is related to the genus of the graph of the curve in $C^2$ (where one uses complex values for both variables). The surface is a punctured multi-holed torus of genus $g$ with the punctures being “at infinity”.
The genus is as follows: 0 if the degree is 1 or 2, 1 if the degree is 3, and greater than 1 if the degree is 4 or higher. So what about the number of rational points:
0 or finite if the genus is zero
finite if the genus is strictly greater than 1 (Falting’s Theorem; 1983)
indeterminate if the genus is 1. Hence much work is done in this area.
No general algorithm is known to make the determination if the curve is cubic (and therefore of genus 1)
Note: the set of rational points has a group structure.
Note: a rational cubic has a rational change of variable which changes the curve to elliptic form:
Weierstrauss form: $y^2 = x^3 + Ax + B$ where $A, B$ are integers.
Hence this is the form that is studied.
Sometimes the rational points can be found in the following way (example: $y^2 = x^3 + 2x + 3$:
note: this curve is symmetric about the $x$ axis.
$(-1, 0)$ is a rational point. So is $(3, 6)$. This line intersects the curve in a third point; this line and the cubic form a cubic in $x$ with two rational roots; hence the third must be rational. So we get a third rational point. Then we use $(3, -6)$ to obtain another line and still another rational point; we keep adding rational points in this manner.
This requires proof, but eventually we get all of the rational points in this manner.
The minimum number of “starting points” that we need to find the rational points is called the “rank” of the curve. Our curve is of rank 1 since we really needed only $(3, 6)$ (which, after reflecting, yields a line and a third rational point).
Mordell’s Theorem: every cubic is of finite rank, though it is unknown (as of this time) what the maximum rank is (maximum known example: rank 28), what an expected size would be, or even if “most” are rank 0 or rank 1.
Note: rank 0 means only a finite number of rational points.
Smaller talks
I enjoyed many of the short talks. Of note:
there was a number theory talk by Jay Schiffman in which different conjectures of the following type were presented: if $S$ is some sequence of positive integers and we look at the series of partial sums, or partial products (plus or minus some set number), what can we say about the number of primes that we obtain?
Example: Consider the Euclid product of primes (used to show that there is no largest prime number)
$E(1) = 2 + 1 = 3, E(2) = 2*3 + 1 = 7, E(3) = 2*3*5 + 1 = 31, E(4) = 2*3*5*7 + 1 = 211$ etc. It is unknown if there is a largest prime in the sequence $E(1), E(2), E(3)....$.
Another good talk was given by Charlie Smith. It was about the proofs of the irrationality of various famous numbers; it was shown that many of the proofs follow a similar pattern and use a series of 3 techniques/facts that the presenter called “rabbits”. I might talk about this in a later post.
Another interesting talk was given by Jack Mealy. It was about a type of “hyper-hyperbolic” geometry called a “Snell geometry”. Basically one sets up the plane and then puts in a smooth closed boundary curve (say, a line or a sphere). One then declares that the geodesics are those that result from a straight lines…that stay straight until they hit the boundary; they then obey the Snell’s law from physics with respect to the normal of the boundary surface; the two rays joined together from the geodesic in the new geometry. One can do this with, say, a concentric series of circles.
If one arranges the density coefficient in the correct manner, one’s density (in terms of area) can be made to increase as one goes outward; this can lead to interesting area properties of triangles.
## August 5, 2011
### Blogging MathFest, 2011 (Lexington, KY)
Filed under: advanced mathematics, algebraic curves, conference, elementary number theory, number theory — collegemathteaching @ 1:50 am
I started the day by attending three large lectures:
Laura DeMarco, University of Illinois at Chicago who spoke about dynamical systems (that result from complex polynomials; for example if $f: C \rightarrow C$ is a function of the complex plane, one can talk about the orbit of a point $z \in C, z, f(z), f(f(z)) = f^{(2)}(z), f(f(f(z))) = f^{(3)}(z)....$. One can then talk about sets of points $w, w\in C$ and $sup|f^{(n)}| < \infty$ This is called the Filled Julia Set.
Ed Burger of Williams (a graduate school classmate of mine who made good) gave the second; he talked about Fibonacci numbers and their relation to irrational ratios (which can be obtained by continued fractions) and various theorems which say that natural numbers can be written uniquely as specified sums of such gadgets.
Lastly Manjul Bhargava of Princeton (who is already full professor though he is less than half my age; he was an Andrew Wiles student) gave a delightful lecture on algebraic curves.
What I noted: all three of these mathematicians are successful enough to be arrogant (especially the third). They could have blown us all away. Yes, they took the time and care to give presentations that actually taught us something.
Of the three, I was the most intrigued by the last one, so I’ll comment on the mathematics.
You’ve probably heard that a Pythagorean triple is a triple of integers $a, b, c$ such that $a^2 + b^2 = c^2$. For now, we’ll limit ourselves to primitive triples; that is, we’ll assume that $a, b, c$ have no common factor.
You might have heard that any Pythagorean triple is of the form: $a = m^2 - n^2, b = 2mn, c = m^2 + n^2$ for $m, n$ integers. It is true that $a, b, c$ being defined that way leads to a Pythagorean triple, but why do ALL Pythagorean triples come in this form?
One way to see this is to look at an algebraic curve; in this case, the curve corresponding to $x^2 + y^2 = 1$. Why? Start with $a^2 + b^2 = c^2$ and divide both sides by $c^2$ to obtain $((\frac{a}{c})^2 + (\frac{b}{c})^2 = 1$ One then notes that one is now reduced to looking to rational solutions to $x^2 + y^2 = 1$ (a rational solution to this can be put in the $((\frac{a}{c})^2 + (\frac{b}{c})^2 = 1$ form by getting a common denominator).
We now wish to find all rational points (both coordinates rational) on the circle; clearly $(-1,0)$ is one of them.
Easy claim: if $(u, v)$ is such a rational point, then the line from $(-1,0)$ to $(u, v)$ has rational slope.
Not quite as easy claim: if a line running through $(-1, 0)$ has rational slope $s < \infty$ then the line intersects the circle in a rational point.
Verification: such a line has equation $y = s(x+1)$ and intersects the circle in a point whose $x$ value satisfies $x^2 + s^2(x+1)^2-1 = 0$. This is a quadratic that has rational coefficients and root $x = -1$ hence the second root must also be rational. Let’s calculate the second root by doing division: $\frac{(s^2 + 1)x^2 +2s^2x + s^2-1}{x+1} = (s^2+1)x + s^2 - 1$. So the point of intersection has $x = \frac{1-s^2}{s^2 + 1}$ latex and $y = s(\frac{1-s^2}{s^2 + 1} + 1) = \frac{2s}{s^2 + 1}$. Both are rational.
Therefore, there is a one to one correspondence between rational slopes and rational points on the circle and all are of the form $(\frac{1-s^2}{s^2 +1}, \frac{2s}{s^2 + 1})$. Note: we obtain $(-1,0)$ by letting $s$ go to infinity; use L’Hopital’s rule on the first coordinate). So if we have any Pythagorean triple $(a,b,c)$ then $\frac{a}{c} = \frac{1-s^2}{s^2 + 1}, \frac{b}{c} = \frac{2s}{s^2 + 1}.$ But $s$ is rational hence we write $s = \frac{p}{q}$ where $p, q$ are relatively prime integers. Just a bit of easy algebra reveals $\frac{a}{c} = \frac{q^2 -p^2}{p^2 + q^2}, \frac{b}{c} = \frac{2pq}{p^2 + q^2}$ which gives us $a = q^2 - p^2, b =2pq, c = q^2 + p^2$ as required.
The point: the algebraic curve motivated the proof that all Pythagorean triples are of that form.
Note: we can extract even more: if $f(x,y) = 0$ latex is any quadratic rational curve (i. e., $f(x,y) = a_1 x^2 + a_2 x + a_3 + a_4 y^2 + a_5 y + a_6 xy$, all coefficients rational, and $(u, v)$ is any rational point and there is a line through $(u,v)$ of rational slope $s$ which intersects the curve in a second point (the quadratic nature forbids more than 2 points), the second point must also be rational. This follows by obtaining a quadratic in $x$ by substituting $y = s(x - u) + v$ and obtaining a quadratic with rational coefficients that has one rational root.
Of course, it might be the case that there is no rational point to choose for $(u, v)$. In fact, that is the case for $x^2 + y^2 = 3.$
Why? Suppose there is a rational point on this curve $x = \frac{p}{q}, y = \frac{a}{b}$ with both fractions in lowest terms. We obtain $(pb)^2 + (aq)^2 = 3(qb)^2$ Now let’s work Mod 4 (hint from the talk): note that in $mod 4, 2^2 = 0, 3^2 = 1$ therefore the sum of two squares can only be 0, 1 or 2. The right hand side is either 3 or 0; equality means that both sides are zero. This means that $pb, aq$ are both even and therefore $3(qb)^2$ is divisible by 4 therefore either $q$ is even or $b$ is even.
Suppose $b$ is odd. Then $q$ is even and because $pb$ is even, $p$ is even. This contradicts the fact that $p, q$ are relatively prime. If $q$ is odd, then because $aq$ is even, $a$ is even. This contradicts the fact that $a, b$ are relatively prime. So both $q, b$ are even which means that $p, a$ are odd. Write $q = 2^I m, b = 2^J n$ where $m, n$ are odd (possibly 1). Then $(p^2)(2^{2J})n^2 + (a^2)(2^{2I}) m^2 = 2^{2J + 2I}3 m^2n^2$. Now if $J = I$ we obtain $(pn)^2 + (am)^2$ on the left hand side (sum of two odd numbers squared) which must be 2 mod 4. The right hand side is still only 3 or 0; this is impossible. Now if, say, $J \ge I$ then we get $(pn)^2 2^{2(J-I)} + (am)^2 = 2^{2J} 3 (mn)^2$ which means that the odd number $(am)^2$ is the difference of two even numbers. That too is impossible.
Hence $x^2 + y^2 = 3$ contains no rational coordinates; that circle manages to miss that dense set.
The point of all of this is that algebraic curves can yield significant information about number theory.
Photos
This is the German Enigma Coding machine (with plug board) at the NSA booth.
This is another view of the Enigma | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 290, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8965559005737305, "perplexity": 271.5868361229141}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084890187.52/warc/CC-MAIN-20180121040927-20180121060927-00098.warc.gz"} |
http://www.gradesaver.com/textbooks/math/algebra/intermediate-algebra-6th-edition/chapter-5-section-5-1-exponents-and-scientific-notation-exercise-set-page-262/70 | ## Intermediate Algebra (6th Edition)
$\frac{15}{16}$
We are given the expression $1^{-3}-4^{-2}$ $1^{-3}-4^{-2}=\frac{1}{1^{3}}-\frac{1}{4^{2}}=1-\frac{1}{16}=\frac{16}{16}-\frac{1}{16}=\frac{15}{16}$ In general, $a^{-n}=\frac{1}{a^{n}}$ (where a is a nonzero real number and n is a positive integer). | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9188057780265808, "perplexity": 267.1876034289652}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934806353.62/warc/CC-MAIN-20171121113222-20171121133222-00537.warc.gz"} |
https://tex.stackexchange.com/questions/63232/why-can-words-with-hyphen-char-not-be-hyphenated/63234 | # Why can words with hyphen char not be hyphenated?
Assume I have a word like Baden-Württemberg. TeX can't hyphenate any of these two word parts. Why?
why isn't it something like this:
where the small ticks indicate possible hyphenation points. A technical (TeXnical) explanation is welcome.
BTW: I am not asking how to circumvent this (by using the babel shorthand "= for example).
• Because so decided Knuth. – egreg Jul 13 '12 at 19:35
• @egreg but why? I mean, what parts of TeX makes decide to disable hyphenation? Is there an explicit "if word contains hyphen char, then exit" somewhere in the hyphenation routine? – topskip Jul 13 '12 at 19:37
• See the posting Switch meaning of hyphenation commands for a LuaLaTeX-based solution, which changes all instances of - on the fly to "= if they (the instances of -) are sandwiched between two letters. Thus, Baden-Württemberg, branchen-üblich, and Gesäß-Muskulatur (and many others!) can automatically be hyphenated at many additional places. :-) – Mico Aug 7 '16 at 19:53
The TeXbook, page 454, last but one double dangerous bend paragraph
If a trial word l1 … ln has been found by this process, hyphenation will still be abandoned unless n ≥ λ + ρ, where λ = max(1,|\lefthyphenmin|) and ρ = max(1,|\righthyphenmin|). (Plain TeX takes λ = 2 and ρ = 3.) Furthermore, the items immediately following the trial word must consist of zero or more characters, ligatures, and implicit kerns, followed immediately by either glue or an explicit kern or a penalty item or a whatsit or an item of vertical mode material from \mark, \insert, or \vadjust. Thus, a box or rule or math formula or discretionary following too closely upon the trial word will inhibit hyphenation. (Since TeX inserts empty discretionaries after explicit hyphens, these rules imply that already-hyphenated compound words will not be further hyphenated by the algorithm.)
An explicit hyphen is a character whose character code matches the font's \hyphenchar value or a ligature that ends with such a character (that's why also -- or --- inhibit hyphenation).
Indeed, if you try the following example, you'll see that TeX hyphenates the compound word:
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
\begin{document}
\hyphenchar\font=\string"7F
\end{document}
The result is
In
Ba-
den-Würt-
tem-
berg
The T1 encoded fonts have in position 0x7F a character which is identical to the normal hyphen. Changing the \hyphenchar to denote this slot, the normal hyphen does not inhibit hyphenation any more.
• 8 consecutive lines with hyphenated words in the TeXbook (the mentioned paragraph). That should be worth a Knuth-error-award-cheque. – topskip Jul 13 '12 at 19:55
• @PatrickGundlach Read at the bottom of page 451. :) – egreg Jul 13 '12 at 19:59
• This solution works fine for me if I just load fontenc with the T1 encoding so that it uses cm-super. However, if I load lmodern as well, for example, it doesn't seem to work. Looking at the encoding files, both seem to put hyphen.alt in that spot. Does anybody know why it doesn't work with lmodern? – cfr Nov 26 '13 at 23:07
• @egreg Am I right that changing \hyphenchar ist not really a practical »solution«? One would need to change it for all fonts and fonts series in use to get uniform behaviour for a document... (and still a "= may be needed in Baden-Württemberg so there isn't much gained when typing, anyway) – clemens Feb 27 '14 at 11:49
• @cgnieder Yes, you're right. IIRC, there should a package that can hook the choice of \hyphenchar at every font loading; but also hyphenation patterns should be modified to have possible breaks at - (the usual hyphen). – egreg Feb 27 '14 at 11:55
The \hyphenchar\font=\string"7F seems not the correct work around for this problem, since it is not font independent.
A better way would be to set the \defaulthyphenchar=127 which seems font independent. Also hyphenation which are defined in acronyms will be correct too. BUT there are still issues when having hyphens in the text like:
Baden-W\"urttemberg
\gls{BP}-Test
If you look at "den-Würt-", it is still not split correctly into two lines. Also the last example "BP-Test" isn't split. The only work around I have found is to use "= instead of - in the text which works for now. But I would appreciate a better solution...
Here is the MWE:
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
%\usepackage{lmodern}
\usepackage{mathptmx}
\usepackage[
nonumberlist,
acronym,
nopostdot,
section]
{glossaries}
\newacronym{BP}{BP}{Borderline-Pers\"onlichkeitsst\"orung}
\defaulthyphenchar=127
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http://www.science.gov/topicpages/p/p-wave+arrival+times.html | #### Sample records for p-wave arrival times
1. Whole mantle P-wave travel time tomography
Hiroshi Inoue; Yoshio Fukao; Kunio Tanabe; Yosihiko Ogata
1990-01-01
A method of tomographic inversion to obtain three-dimensional velocity perturbations in the Earth's whole mantle has been developed, and applied to more than two million P-wave arrival time data reported by International Seismology Center (ISC). The model is parameterized with 32,768 blocks; the divisions in latitude, longitude, and radius are 32, 64, and 16, respectively. Horizontal cell size is 5.6°
2. Mantle Under the Vrancea Zone - Evidence from Dispersion of First-arriving P-Waves
Rodler, Fee-Alexandra; Bokelmann, Götz; Gerner, Andreas
2013-04-01
The Vrancea region of the south-eastern Carpathians is one of the most active seismic zones in Europe and is known for its intermediate-depth seismicity, e.g., there are strong earthquakes in a very limited seismogenic volume at intermediate-depth (70-180 km). Seismic tomography has shown a high-velocity body in that anomalous zone, extending to a depth of at least 350 km. That high-velocity body has been interpreted either as a descending lithospheric slab or as mantle lithosphere. Indeed, the regional geodynamic models proposed for this area can be split into two main model assumptions: (a) The mantle seismicity in Vrancea is associated with a descending relic oceanic lithosphere (attached or already detached from the continental crust) beneath the bending zone of the SE-Carpathians, or (b) the intermediate depth earthquakes are caused by delamination of mantle lithosphere due to continental collision and orogenic thickening. In order to shed more light on the origin of the intermediate depth seismicity in the Vrancea zone, we investigate the frequency-dependence of P-wave group arrival times of local earthquakes excited beneath this area. Dispersed P-waves have been observed in many subduction zones around the world. A most natural, and almost exclusive, explanation is based on the upper few kilometers of subducted oceanic crust that are seismically distinct from surrounding material. Such a low-velocity layer several kilometers thick acts as a waveguide, causing higher frequencies to arrive later than lower frequencies. For Vrancea, such dispersion is observed at several stations sited at the bending zone of the SE-Carpathians while signals at a reference station further northwest do not show such a behaviour. The main interest of this technique is that it provides constraints that classical seismic tomography can not give, since the low-velocity channel is too thin to be resolved by the latter technique. The presence of a tabular and inclined low-velocity suggests the presence of subducted oceanic lithosphere rather than continental lithospheric delamination as the best simple geodynamic model for the area.
3. Walk-Run Activity: An S and P Wave Travel Time Simulation
NSDL National Science Digital Library
Larry Braile
In this activity, students use walking and running speeds to simulate the difference in S- and P-wave travel times, a property used in the location of earthquakes. They will construct travel time curves using their measurements of walking and running arrival times and calculate the epicenter of a hypothetical earthquake by using triangulation.
4. Nature of the Vrancea seismic zone (Eastern Carpathians) - New constraints from dispersion of first-arriving P-waves
Bokelmann, Götz; Rodler, Fee-Alexandra
2014-03-01
The Vrancea region of the southeastern Carpathians is one of the most active seismic zones in Europe and it is well-known for its strong intermediate depth earthquakes. Seismic tomography had revealed a high-velocity body beneath Vrancea and the Moesian platform that extends to a depth of at least 350 km and can be interpreted as descending lithosphere. The strong earthquakes occur within the northeastern part of this high-velocity body, in a very limited seismogenic volume at intermediate depth (70-180 km). Several geodynamic models have been proposed for this area. They can be split into two main categories, in terms of the nature of the high-velocity anomaly, which may (a) be associated with descending relic oceanic lithosphere beneath the bending zone of the SE-Carpathians, either attached or already detached from the continental crust; or (b) it may represent continental lithosphere that has been delaminated, after continental collision and orogenic thickening. Based on currently available information, it appears difficult to distinguish between these two types of models. In this paper we attempt to shed more light on the nature of the seismic anomaly, as well as that of the origin of the intermediate depth seismicity in the Vrancea zone, by investigating the waveform character of P-waves excited by local earthquakes beneath this area, and in particular the dependence of group arrival times on frequency. We present observations of such a dispersion from stations situated at the bending zone of the SE-Carpathians. On the other hand, signals from the same earthquakes, but observed at reference stations outside of the anomalous zone do not show that frequency dependence. A natural explanation for these observations is that it is caused by the presence of a low-velocity channel at the top of the seismic anomaly, which is too thin to be resolved by classical seismic tomographic techniques. Similar observations of dispersed first-arriving P-waves have been made above subduction zones around the world, in which low-velocity layers with a thickness of several kilometers are known to exist. This suggests that a tabular slab of subducted oceanic crust is present within the seismic anomaly under the Vrancea region, and that the anomaly consists of subducted oceanic lithosphere rather than continental lithosphere, at least at depths shallower than the seismically active zone.
5. Final Arrival Location: Final Arrival Date: Final Arrival Time: FOREIGN TRAVEL
E-print Network
Bigelow, Stephen
Final Arrival Location: Final Arrival Date: Final Arrival Time: FOREIGN TRAVEL REIMBURSEMENT obtain a Travel Advance for this trip? No Yes Was there any personal time during this trip? No Yes From.S. Citizen: Yes No City of Residence: Vendor I.D. # (if known): Purpose of Travel: Destination: Did you
6. Final Arrival Location: Final Arrival Date: Final Arrival Time: FOREIGN TRAVEL
E-print Network
Ahlers, Guenter
Final Arrival Location: Final Arrival Date: Final Arrival Time: FOREIGN TRAVEL REIMBURSEMENT: ______________________ Date:_____________________ Non-UC travelers - your SSN # is required:_______________ U.S. Citizen: Yes): _______________________ Purpose of Travel: Destination: Did you obtain a Travel Advance for this trip? No Yes Was there any
7. Real-Time Prediction of Ground Motion from P-Wave Records
Boese, M.; Erdik, M.; Wenzel, F.
2004-12-01
Real-time prediction of ground motion parameters, such as peak values, seismic intensity or spectral response, at a critical site or facility as well as on regional scale, can help to reduce losses by strong earthquakes by the automatic triggering of protective steps seconds prior to the arrival of high amplitude seismic waves. We present a concept for an earthquake early warning system designed for real-time processing of information obtained from the low amplitude P-wave that is recorded at a number of accelerographs installed in the epicentral area. To allow for the adaptation to rupture dynamics, the estimation of ground motion parameters starts as soon as the first station is triggered and is continuously up-dated with ongoing time. Our design is in contrast to other earthquake early warning systems that are based on the explicit knowledge of magnitude and hypocenter location for the application of empirical attenuation laws. The level of the cumulative absolute velocity (CAV) of the P-wave as well as relative values of CAV at different seismic stations give a good indicator for the severity of impending ground shaking. The site-specific prediction of ground motion parameters and interpolation for the generation of regional shake maps is achieved by the application of a three-layer feedforward neural network considering local site effects. The procedure is demonstrated for the Istanbul Earthquake Early Warning System in Turkey.
8. Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume II P-Wave Measurements in Borehole C4996 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.
SciTech Connect
Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh
2007-07-06
9. Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume III P-Wave Measurements in Borehole C4997 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.
SciTech Connect
Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh
2007-06-06
10. Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume I P-Wave Measurements in Borehole C4993 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.
SciTech Connect
Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh
2007-07-06
11. Quantum arrival time for open systems
SciTech Connect
Yearsley, J. M. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)
2010-07-15
We extend previous work on the arrival time problem in quantum mechanics, in the framework of decoherent histories, to the case of a particle coupled to an environment. The usual arrival time probabilities are related to the probability current, so we explore the properties of the current for general open systems that can be written in terms of a master equation of the Lindblad form. We specialize to the case of quantum Brownian motion, and show that after a time of order the localization time of the current becomes positive. We show that the arrival time probabilities can then be written in terms of a positive operator-valued measure (POVM), which we compute. We perform a decoherent histories analysis including the effects of the environment and show that time-of-arrival probabilities are decoherent for a generic state after a time much greater than the localization time, but that there is a fundamental limitation on the accuracy {delta}t, with which they can be specified which obeys E{delta}t>>({h_bar}/2{pi}). We confirm that the arrival time probabilities computed in this way agree with those computed via the current, provided there is decoherence. We thus find that the decoherent histories formulation of quantum mechanics provides a consistent explanation for the emergence of the probability current as the classical arrival time distribution, and a systematic rule for deciding when probabilities may be assigned.
12. Walk -Run Activity --An S and P Wave Travel Time ("S minus P" Earthquake Location Method)
E-print Network
Smith-Konter, Bridget
Walk - Run Activity --An S and P Wave Travel Time Simulation ("S minus P" Earthquake Location between distance and time of travel of seismic waves (a travel time-curve). To use the constructed time-travel pencils) Procedure: Part One: Constructing the Travel-Time Graph To model how earthquake waves travel
13. HELCATS Prediction of Planetary CME arrival times
Boakes, Peter; Moestl, Christian; Davies, Jackie; Harrison, Richard; Byrne, Jason; Barnes, David; Isavnin, Alexey; Kilpua, Emilia; Rollett, Tanja
2015-04-01
We present the first results of CME arrival time prediction at different planetary locations and their comparison to the in situ data within the HELCATS project. The EU FP7 HELCATS (Heliospheric Cataloguing, Analysis & Techniques Service) is a European effort to consolidate the exploitation of the maturing field of heliospheric imaging. HELCATS aims to catalogue solar wind transients, observed by the NASA STEREO Heliospheric Imager (HI) instruments, and validate different methods for the determination of their kinematic properties. This validation includes comparison with arrivals at Earth, and elsewhere in the heliosphere, as well as onsets at the Sun (http://www.helcats-fp7.eu/). A preliminary catalogue of manually identified CMEs, with over 1000 separate events, has been created from observations made by the STEREO/HI instruments covering the years 2007-2013. Initial speeds and directions of each CME have been derived through fitting the time elongation profile to the state of the art Self-Similar Expansion Fitting (SSEF) geometric technique (Davies et al., 2012). The technique assumes that, in the plane corresponding to the position angle of interest, CMEs can be modelled as circles subtending a fixed angular width to Sun-center and propagating anti-sunward in a fixed direction at a constant speed (we use an angular width of 30 degrees in our initial results). The model has advantages over previous geometric models (e.g. harmonic mean or fixed phi) as it allows one to predict whether a CME will 'hit' a specific heliospheric location, as well as to what degree (e.g. direct assault or glancing blow). We use correction formulae (Möstl and Davies, 2013) to convert CME speeds, direction and launch time to speed and arrival time at any in situ location. From the preliminary CME dataset, we derive arrival times for over 400 Earth-directed CMEs, and for over 100 Mercury-, Venus-, Mars- and Saturn-directed CMEs predicted to impact each planet. We present statistics of predicted CME arrival properties. In addition, we independently identify CME arrival at in situ locations using magnetic field data from the Venus Express, Messenger, and Ulysses spacecraft and show first comparisons to predicted arrival times. The results hold important implications for space weather prediction at Earth and other locations, allowing model and predicted CME parameters to be compared to their in situ counterparts.
14. P-WAVE TIME-LAPSE SEISMIC DATA INTERPRETATION AT RULISON FIELD, PICEANCE BASIN, COLORADO
E-print Network
in the Williams Fork, based on ultrasonic core measurements and diagnostic fracture initiation testsP-WAVE TIME-LAPSE SEISMIC DATA INTERPRETATION AT RULISON FIELD, PICEANCE BASIN, COLORADO by Donald School of Mines in partial fulfillment of the requirements for the degree of Master of Science
15. Target tracking and Estimated Time of Arrival (ETA) Prediction for Arrival Aircraft
E-print Network
California at Irvine, University of
Target tracking and Estimated Time of Arrival (ETA) Prediction for Arrival Aircraft Kaushik Roy Benjamin Levy Claire J. Tomlin§ The problem of developing a unified algorithm for arrival aircraft target. One bottleneck in the flow of aircraft is traffic on the surface of and in the air surrounding
16. Relativistic free-motion time-of-arrival
E-print Network
Zhi-Yong Wang; Cai-Dong Xiong
2007-10-22
Relativistic free-motion time-of-arrival theory for massive spin-1/2 particles is systematically developed. Contrary to the nonrelativistic time-of-arrival operator studied thoroughly in previous literatures, the relativistic time-of-arrival operator possesses self-adjoint extensions because of the particle-antiparticle symmetry. The nonrelativistic limit of our theory is in agreement with the nonrelativistic time-of-arrival theory. By comparing the time-of-arrival operator with the Hamiltonian operator of a free Dirac particle, one can show a duality between position space and momentum space.
17. Acceleration of stable TTI P-wave reverse-time migration with GPUs
Kim, Youngseo; Cho, Yongchae; Jang, Ugeun; Shin, Changsoo
2013-03-01
When a pseudo-acoustic TTI (tilted transversely isotropic) coupled wave equation is used to implement reverse-time migration (RTM), shear wave energy is significantly included in the migration image. Because anisotropy has intrinsic elastic characteristics, coupling P-wave and S-wave modes in the pseudo-acoustic wave equation is inevitable. In RTM with only primary energy or the P-wave mode in seismic data, the S-wave energy is regarded as noise for the migration image. To solve this problem, we derive a pure P-wave equation for TTI media that excludes the S-wave energy. Additionally, we apply the rapid expansion method (REM) based on a Chebyshev expansion and a pseudo-spectral method (PSM) to calculate spatial derivatives in the wave equation. When REM is incorporated with the PSM for the spatial derivatives, wavefields with high numerical accuracy can be obtained without grid dispersion when performing numerical wave modeling. Another problem in the implementation of TTI RTM is that wavefields in an area with high gradients of dip or azimuth angles can be blown up in the progression of the forward and backward algorithms of the RTM. We stabilize the wavefields by applying a spatial-frequency domain high-cut filter when calculating the spatial derivatives using the PSM. In addition, to increase performance speed, the graphic processing unit (GPU) architecture is used instead of traditional CPU architecture. To confirm the degree of acceleration compared to the CPU version on our RTM, we then analyze the performance measurements according to the number of GPUs employed.
18. Time-dependent three dimensional P-wave velocity models derived for the Geysers geothermal field
Friberg, P. A.; Roecker, S. W.; Dricker, I. G.; Lisowski, S.; Hellman, S. B.
2011-12-01
The Geysers geothermal field is a source of significant small earthquake (M< 2.0) seismicity in northern California. The region has been actively monitored for seismicity, both natural and induced, since the geothermal field has been put into production. A modern digital seismic monitoring network in the area consists of 34 LBNL/Calpine (BG) borehole short-period and 12 Northern California Seismic Network (NCSN) network surface short-period seismic stations. The USGS has auto-located approximately 25,033 earthquakes (NCEDC catalog) for the years 2009 and 2010 combined from the composite seismic network. Using the auto-located solutions and a Geysers specific one-dimensional velocity model (Eberhart-Philips and Oppenheimer, 1984) as a starting point, we have simultaneously inverted for three dimensional P-wave velocities for each year's data set. Before beginning the inversion we established that the automatic S-phase picks were too unstable and thus focused only on the P-wave velocities. After culling events with initial RMS uncertainty greater than 0.06 seconds, we start with 7,403 earthquakes in 2009 and 11,199 earthquakes in 2010. The technique we use is a finite-difference travel time technique that Roecker et al. (Tectonophysics, 2006) used for the Parkfield SAFOD site. We will present the results of the simultaneous inversion for each of the 2009 and 2010 years along with plots of the seismicity relocated using these new velocity models.
19. Arrival Times of Satellite-Broadened Laser Pulses
R. S. Iyer
1976-01-01
A method for measuring the time of arrival of very narrow laser pulses which have been reflected and randomly broadened by a target is examined. It is known that these return pulses from the target have very small rise times. A threshold detection algorithm that detects the rising edge of the pulse is used for obtaining the pulse arrival times.
20. Regional Tomographic Inversion of P-wave Travel Times in Central Chile and Argentina, between 30° and 36° south.
Wagner, L. S.; Beck, S.; Zandt, G.; Araujo, M.; Campos, J.; Charge Working Group,.
2003-12-01
We use regional P-wave travel times to model upper mantle structure beneath Chile and Argentina between 30° and 36° S. This area is of particular interest, because north of 33° S, the subducted Nazca plate descends normally to a depth of 100 km, but then flattens out, continuing along a subhorizontal path for some 400 km before resuming a normal subduction angle and descending into the mantle. South of 33° , the Nazca plate subducts with a constant dip. This difference in subduction style from the north to the south is correlated with changes in volcanism, seismicity, and orogenic structure. Data for this study comes from the CHARGE project, a 22 station broadband portable seismic deployment, and first arrival P-picks from the ISC catalog recorded at an additional 30 stations operated by INPRES and the Seismological Service of the Universidad de Chile. We use the tomographic inversion method of Zhao et al. [1994] to invert over 3100 P-wave picks from over 170 events recorded at 54 stations. This tomography method allows for the introduction of discrete discontinuities, such as the Moho and the top of the subducting slab, which allows for clearer vertical resolution because smearing across these boundaries is reduced. Preliminary results show evidence of low velocity zones possibly associated with the dehydration of the subducting oceanic plate. To the south where the Nazca plate descends at a dip of 30° , the low velocity zone appears to be confined to a narrow area above where the subducted plate reaches ~100 - 125 km depth and corresponds to the region beneath the active volcanic arc. To the north, the low velocity zone persists, extending east beneath the Sierras Pampeanas. This correlates well with the flat slab area, indicating that the Nazca plate may dewater continuously as it subducts east until it resumes a normal descent angle into the mantle. However, arc volcanism north of 33° S has been dormant for 8 Ma, suggesting that it is the cold thermal regime of the flat slab, rather than a lack of water, that is primarily responsible for shutting down the arc volcanism. Zhao, D., A. Hasegawa, and H. Kanamori, Deep structure of Japan subduction zone as derived from local, regional, and teleseismic events, Journal of Geophysical Research, 99, 22313-22329, 1994.
1. Prediction of the shock arrival time with SEP observations
G. Qin; M. Zhang; H. K. Rassoul
2009-01-01
Real-time prediction of the arrival times at Earth of shocks is very important for space weather research. Recently, various models for shock propagation are used to forecast the shock arriving times (SATs) with information of initial coronal shock and flare from near real-time radio and X-ray data. In this paper, we add the use of solar energetic particles (SEP) observation
2. Wave separation: application for arrival time detection in ultrasonic signals.
PubMed
Avanesians, Patrick; Momayez, Moe
2015-01-01
A method to detect and accurately measure the arrival time of wave packets in ultrasonic signals using a nonlinear decomposition technique is presented. We specifically address the problem of extracting events that are not well separated in the time, space and frequency domains. Analysis of complex ultrasonic signals, even those composed of poorly separated echoes, provided exceptional estimates of the desired time of arrival, from the media under investigation. PMID:25194641
3. Effects of lateral velocity heterogeneity under the Nevada Test Site on short-period P wave amplitudes and travel times
Christopher S. Lynnes; Thorne Lay
1990-01-01
Short-period teleseismicP waves from the Nevada Test Site (NTS) show systematic variations in amplitudes and travel times, with low amplitudes corresponding to fast travel times, suggesting elastic focussing-defocussing effects. Also, the azimuthal amplitude and travel time patterns for events at the Pahute Mesa subsite are systematically different from those at the Yucca Flat subsite, indicating the presence of a near-source
4. Inter-arrival times of message propagation on directed networks
E-print Network
Mihaljev, Tamara; Herrmann, Hans J
2010-01-01
One of the challenges in fighting cybercrime is to understand the dynamics of message propagation on botnets, networks of infected computers used to send viruses, unsolicited commercial emails (SPAM) or denial of service attacks. We map this problem to the propagation of multiple random walkers on directed networks and we evaluate the inter-arrival time distribution between successive walkers arriving at a target. We show that the temporal organization of this process, which models information propagation on unstructured peer to peer networks, has the same features as SPAM arriving to a single user. We study the behavior of the message inter-arrival time distribution on three different network topologies using two different rules for sending messages. In all networks the propagation is not a pure Poisson process. It shows universal features on Poissonian networks and a more complex behavior on scale free networks. Results open the possibility to indirectly learn about the process of sending messages on networ...
5. LLNL-G3Dv3: global P-wave tomography model for improved regional and teleseismic travel time prediction
Simmons, N. A.; Myers, S. C.; Johannesson, G.; Matzel, E.
2013-05-01
We develop a global-scale P-wave velocity model (LLNL-G3Dv3) designed to accurately predict seismic travel times at regional and teleseismic distances simultaneously. The model provides a new image of Earth's interior, but the underlying practical purpose of the model is to provide enhanced seismic event location capabilities. The LLNL-G3Dv3 model is based on ~2.8 million P and Pn arrivals that are re-processed using our global multiple-event locator called Bayesloc. We construct LLNL-G3Dv3 within a spherical tessellation based framework, allowing for explicit representation of undulating and discontinuous layers including the crust and transition zone layers. Using a multi-scale inversion technique, regional trends as well as fine details are captured where the data allow. LLNL-G3Dv3 exhibits large-scale structures including cratons and superplumes as well numerous complex details in the upper mantle including within the transition zone. Particularly, the model reveals new details of a vast network of subducted slabs trapped within the transition beneath much of Eurasia, including beneath the Tibetan Plateau. We demonstrate the impact of Bayesloc multiple-event location on the resulting tomographic images through comparison with images produced without the benefit of multiple-event constraints (single-event locations). We find that the multiple-event locations allow for better reconciliation of the large set of direct P phases recorded at 0-97° distance and yield a smoother and more continuous image relative to the single-event locations. Travel times predicted from a 3-D model are also found to be strongly influenced by the initial locations of the input data, even when an iterative inversion/relocation technique is employed. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-559093 Summary of the LLNL-G3Dv3 model architecture. a) Selected levels of the spherical tessellation grids that define the location of nodes in the lateral extent. Nodes are placed at arbitrary radii in the direction of geocentric vectors pointing from the center of the Earth to the vertices. This hierarchical model structure is exploited in the PMTI imaging technique [see Simmons et al., 2011]. b) Description of the model layers.
6. Time-of-arrival probabilities for general particle detectors
E-print Network
Charis Anastopoulos; Ntina Savvidou
2012-07-16
We develop a general framework for the construction of probabilities for the time of arrival in quantum systems. The time of arrival is identified with the time instant when a transition in the detector's degrees of freedom takes place. Thus, its definition is embedded within the larger issue of defining probabilities with respect to time for general quantum transitions. The key point in our analysis is that we manage to reduce the problem of defining a quantum time observable to a mathematical model where time is associated to a transition from a subspace of the Hilbert space of the total system to its complementary subspace. This property makes it possible to derive a general expression for the probability for the time of transition, valid for any quantum system, with the only requirement that the time of transition is correlated with a definite macroscopic record. The framework developed here allows for the consideration of any experimental configuration for the measurement of the time of arrival and it also applies to relativistic systems with interactions described by quantum field theory. We use the method in order to describe time-of-arrival measurements in high-energy particle reactions and for a rigorous derivation of the time-integrated probabilities in particle oscillations.
7. A new pulse arrival-time recording system
SciTech Connect
Arnone, G.J.
1996-12-31
We describe a new pulse arrival-time recording system that is being developed at Los Alamos. The new PATRM/PCI (Pulse Arrival-Time Recording Module/Peripheral Component Interconnect) has had several features added. These features enhance our time-correlation measurement capabilities. By applying the latest advances in electronics and computer technology we are able to increase capability over existing instrumentation while lowering the per channel cost. The modular design approach taken allows easy configuration of both small and large systems.
8. Incorporating fault zone head wave and direct wave secondary arrival times into seismic tomography: Application at Parkfield, California
Bennington, Ninfa L.; Thurber, Clifford; Peng, Zhigang; Zhang, Haijiang; Zhao, Peng
2013-03-01
We present a three-dimensional (3D) P wave velocity (Vp) model of the Parkfield region that utilizes existing P wave arrival time data, including fault zone head waves (FZHWs), and data from direct wave secondary arrivals (DWSAs). The first-arrival and DWSA travel times are obtained as the global- and local-minimum travel time paths, respectively. The inclusion of FZHWs and DWSAs results in as much as a 5% and a 10% increase in the across-fault velocity contrast, respectively, for the Vp model at Parkfield relative to that of Thurber et al. [2006]. Viewed along strike, three pronounced velocity contrast regions are observed: a pair of strong positive velocity contrasts (SW fast), one NW of the 1966 Parkfield earthquake hypocenter and the other SE of the 2004 Parkfield earthquake hypocenter, and a strong negative velocity contrast (NE fast) between the two hypocenters. The negative velocity contrast partially to entirely encompasses peak coseismic slip estimated in several slip models for the 2004 earthquake, suggesting that the negative velocity contrast played a part in defining the rupture patch of the 2004 Parkfield earthquake. Following Ampuero and Ben-Zion (2008), the pattern of velocity contrasts is consistent with the observed bilateral rupture propagation for the 2004 Parkfield earthquake. Although the velocity contrasts also suggest bilateral rupture propagation for the 1966 Parkfield earthquake, the fault is creeping to the NW here, i.e., exhibiting velocity-strengthening behavior. Thus, it is not surprising that rupture propagated only SE during this event.
9. Compound arrival times and a search model of marriage
Peter Mitter
1990-01-01
All customary parametric survival models show a high probability of event occurance at early times. This is not appropriate in most cases where arrival time is age. A way to overcome this problem is the decomposition of the observed period into (not observed) sub?periods with different duration distributions or different exposures to risk. In the search model presented in this
10. Polynomial Time Algorithms for Scheduling of Arrival Kaushik Roy
E-print Network
Polynomial Time Algorithms for Scheduling of Arrival Aircraft Kaushik Roy Alexandre M. Bayen Claire States has again motivated the need for efficiency in the Air Traffic Control (ATC) system. Optimization, leading to large delays throughout the national airspace, reducing efficiency dramatically. A great deal
11. A Comparison of CTAS and Airline Time of Arrival Predictions
NASA Technical Reports Server (NTRS)
Heere, Karen R.; Zelenka, Richard E.; Hsu, Rose Y.
1999-01-01
A statistically-based comparison of aircraft times of arrival between Center/TRACON Automation System (CTAS) air traffic control scheduling and airline predictions is presented. CTAS is found to provide much improved values, forming the foundation for airline operational improvements, as observed during an airline field trial of a CTAS display.
12. Arrival Time Distribution by the New Observation System at Taro
Sakuyama, H.; Obara, Hitoshi; Kuramochi, Hiroshi; Ono, Shunichi; Origasa, Satoru; Mochida, Akinori; Sakuyama, Hiroshi; Suzuki, Noboru
2003-07-01
The arrival time distribution of EAS has been observed by using Ultra Fast Cherenkov detector (UFC) and oscilloscope at Taro observatory since 1995 (sea level 200m). The EAS array is arranged 169 sets of 0.25m2 scintillation detectors in the shape of a lattice at intervals of 1.5m and about 40 scintillation detectors which consists of 1m2 and 0.25m2 is arranged in the peripheral part. Then, it consists of 8 fast timing detectors. The UFC detector is installed in the palce of about 20m from the trigger center. The observation system of a UFC detector was changed from the autumn of 2000. The outline of a new observation system and EAS arrival time distribution are reported.
13. The arrival time distribution of EAS at Taro
Maeda, T.; Kuramochi, H.; Ono, S.; Sakuyama, H.; Suzuki, N.
The arrival time distribution of EAS has been observed since 1995 at Taro cosmicray laboratory (200m above sea level). The EAS arrays consist of 1m2 and 0.25m2 scintillation detectors, 0.25m2 fast timing counters and ultra fast Cherenkov detectors (UFC). 169 0.25m2 scintillation detectors are arranged in alattice configuration with a unit distance of 1.5m. UFC is placed at 20m from the center of lattice array. The arrival time distribution has been analyzed with distance from EAS core (r=10-60m). One of the results shows that the radius of corvature increases as shower size (Ne), near to the EAS core.
14. Quantum arrival and dwell times via idealized clocks
SciTech Connect
Yearsley, J. M.; Downs, D. A.; Halliwell, J. J.; Hashagen, A. K. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)
2011-08-15
A number of approaches to the problem of defining arrival- and dwell-time probabilities in quantum theory makes use of idealized models of clocks. An interesting question is the extent to which the probabilities obtained in this way are related to standard semiclassical results. In this paper, we explore this question using a reasonably general clock model, solved using path-integral methods. We find that, in the weak-coupling regime, where the energy of the clock is much less than the energy of the particle it is measuring, the probability for the clock pointer can be expressed in terms of the probability current in the case of arrival times, and the dwell-time operator in the case of dwell times, the expected semiclassical results. In the regime of strong system-clock coupling, we find that the arrival-time probability is proportional to the kinetic-energy density, consistent with an earlier model involving a complex potential. We argue that, properly normalized, this may be the generically expected result in this regime. We show that these conclusions are largely independent of the form of the clock Hamiltonian.
15. Empirical estimation of the arrival time of ICME Shocks
Shaltout, Mosalam
Empirical estimation of the arrival time of ICME Shocks Mosalam Shaltout1 ,M.Youssef 1and R.Mawad2 1 National Research Institute of Astronomy and Geophysics (NRIAG) ,Helwan -Cairo-Egypt Email: [email protected] 2 Faculty of Science-Monifiia University-Physics Department-Shiben Al-Koum -Monifiia-Egypt We are got the Data of the SSC events from Preliminary Reports of the ISGI (Institut de Physique du Globe, France) .Also we are selected the same CME interval 1996-2005 from SOHO/LASCO/C2.We have estimated the arrival time of ICME shocks during solar cycle 23rd (1996-2005), we take the Sudden storm commencement SSC as a indicator of the arrival of CMEs at the Earth's Magnetosphere (ICME).Under our model ,we selected 203 ICME shock-SSC associated events, we got an imperial relation between CME velocity and their travel time, from which we obtained high correlation between them, R=0.75.
16. UCSF Shuttle GPS coming May 1, 2013 View real-time shuttle arrival times on your
E-print Network
Yamamoto, Keith
real-time arrival predictions via phone, cell phone, or SMT (Text) messaging. · Obtain NextBus alerts UCSF Shuttle GPS coming May 1, 2013 View real-time shuttle arrival times on your phone students, faculty, staff, patients and affiliates will be able use the latest GPS technology to view, track
Borden, J.; Knope, M. L.; Fukami, T.
2009-12-01
18. Upper mantle anisotropy beneath Australia and Tahiti from P wave polarization: Implications for real-time earthquake location
Fabrice R. Fontaine; Guilhem Barruol; Brian L. N. Kennett; Goetz H. R. Bokelmann; Dominique Reymond
2009-01-01
We report measurements of long-period P wave polarization (Ppol) in Australia and Tahiti made by combining modeling of the polarization deviation and harmonic analysis. The analysis of the deviation of the horizontal polarization of the P wave as a function of event back azimuth may be used to obtain information about (1) sensor misorientation, (2) dipping discontinuities, (3) seismic anisotropy,
19. Fault plane orientations of microearthquakes at Mt. Etna from the inversion of P-wave rise times
de Lorenzo, Salvatore; Giampiccolo, Elisabetta; Martinez-Arevalo, Carmen; Patanè, Domenico; Romeo, Annalisa
2010-01-01
A crucial point in the analysis of tectonic earthquakes occurring in a volcanic area is the inference of the orientation of the structures along which the ruptures occur. These structures represent zones of weakness which could favor the migration of melt toward the surface and the assessment of their geometry is a fundamental step toward efficient evaluation of volcanic risk. We analyzed a high-quality dataset of 171 low-magnitude, tectonic earthquakes that occurred at Mt. Etna during the 2002-2003 eruption. We applied a recently developed technique aimed at inferring the source parameters (source size, dip and strike fault) and the intrinsic quality factor Qp of P waves from the inversion of rise times. The technique is based on numerically calibrated relationships among the rise time of first P waves and the source parameters for a circular crack rupturing at a constant velocity. For the most of the events the directivity source effect did not allow us to constrain the fault plane orientation. For a subset of 45 events with well constrained focal mechanisms we were able to constrain the "true" fault plane orientation. The level of resolution of the fault planes was assessed through a non linear analysis based on the random deviates technique. The significance of the retrieved fault plane solutions and the fit of the assumed source model to data were assessed through a ?-square test. Most of the retrieved fault plane solutions agree with the geometrical trend of known surface faults. The inferred source parameters and Qp are in agreement with the results of previous studies.
20. Rounding of Arrival and Departure Times in Travel Surveys: An Interpretation in Terms of Scheduled Activities
Piet Rietveld
2001-01-01
In travel surveys most respondents apply rounding of departure and arrival times to multiples of 5, 15 and 30 minutes: in the annual Dutch travel survey about 85-95 percent of all reported times are 'round' ones. We estimate rounding models for departure and arrival times. The model allows one to compute the probability that a reported arrival time m (say
1. ConcepTest: P Wave Arrival
NSDL National Science Digital Library
Examine the seismogram below that shows a 26-minute long record of the seismic waves from the 1906 San Francisco earthquake as it was received by a seismograph station in Germany, over 14,000 km away. Which letter ...
2. Marginal picture of quantum dynamics related to intrinsic arrival times
SciTech Connect
Torres-Vega, Gabino [Physics Department, Cinvestav, Apartado Postal 14-740, 07000 Mexico City, Distrito Federal (Mexico)
2007-09-15
We introduce a marginal picture of the evolution of quantum systems, in which the representation vectors are the quantities that evolve and operators and wave packets remain static. The representation vectors can be seen as probe functions that are the evolution of a {delta} function with initial support on q=X in coordinate space. This picture of the dynamics is suited for the determination of intrinsic arrival distributions for quantum systems, providing a clear physical meaning to the 'time eigenstates' used in these calculations. We also analyze Galapon et al.'s 'confined time eigenstates' [Phys. Rev. Lett. 93, 180406 (2004)] from this point of view, and propose alternative probe functions for confined systems without the need of a quantized time.
3. Velocity Structure of the Tibetan Lithosphere: Constraints from P-Wave Travel Times of Regional Earthquakes
E-print Network
Nowack, Robert L.
further constraints on Moho structure and upper-mantlelid velocities. We use three-dimensional ray tracing to model the travel times, and the results indicate that the Moho beneath the Lhasa terrane=s. Travel times from events to the west and east of the array indicate that both Moho structure and mantle
4. Early magnitude estimation for the MW7.9 Wenchuan earthquake using progressively expanded P-wave time window
PubMed Central
Peng, Chaoyong; Yang, Jiansi; Zheng, Yu; Xu, Zhiqiang; Jiang, Xudong
2014-01-01
More and more earthquake early warning systems (EEWS) are developed or currently being tested in many active seismic regions of the world. A well-known problem with real-time procedures is the parameter saturation, which may lead to magnitude underestimation for large earthquakes. In this paper, the method used to the MW9.0 Tohoku-Oki earthquake is explored with strong-motion records of the MW7.9, 2008 Wenchuan earthquake. We measure two early warning parameters by progressively expanding the P-wave time window (PTW) and distance range, to provide early magnitude estimates and a rapid prediction of the potential damage area. This information would have been available 40?s after the earthquake origin time and could have been refined in the successive 20?s using data from more distant stations. We show the suitability of the existing regression relationships between early warning parameters and magnitude, provided that an appropriate PTW is used for parameter estimation. The reason for the magnitude underestimation is in part a combined effect of high-pass filtering and frequency dependence of the main radiating source during the rupture process. Finally we suggest only using Pd alone for magnitude estimation because of its slight magnitude saturation compared to the ?c magnitude. PMID:25346344
5. Probability distribution of arrival times in quantum mechanics
E-print Network
1997-12-03
In a previous paper [V. Delgado and J. G. Muga, Phys. Rev. A 56, 3425 (1997)] we introduced a self-adjoint operator $\\hat {{\\cal T}}(X)$ whose eigenstates can be used to define consistently a probability distribution of the time of arrival at a given spatial point. In the present work we show that the probability distribution previously proposed can be well understood on classical grounds in the sense that it is given by the expectation value of a certain positive definite operator $\\hat J^{(+)}(X)$ which is nothing but a straightforward quantum version of the modulus of the classical current. For quantum states highly localized in momentum space about a certain momentum p_0 \ 6. Global-scale P wave tomography optimized for prediction of teleseismic and regional travel times for Middle East events: 1. Data set development NASA Astrophysics Data System (ADS) Myers, S. C.; Johannesson, G.; Simmons, N. A. 2011-04-01 We extend the Bayesloc seismic multiple-event location algorithm for application to global arrival time data sets. Bayesloc is a formulation of the joint probability distribution spanning multiple-event location parameters, including hypocenters, travel time corrections, pick precision, and phase labels. Stochastic priors may be used to constrain any of the Bayesloc parameters. Markov Chain Monte Carlo sampling is used to draw samples from the joint probability distribution, and the posteriori samples are summarized to infer conventional location parameters such as the hypocenter. The first application of the broad area Bayesloc algorithm is to a data set consisting of all well-recorded events in the Middle East and the most well-recorded events with 5° spatial sampling globally. This sampling strategy is designed to provide the ray coverage needed to determine lithospheric-scale P wave velocity structure in the Middle East using the complementary ray geometry provided by regional (subhorizontal) and teleseismic (subvertical) raypaths and to determine a consistent, albeit lower-resolution, image of global mantle structure. The data set consists of 5401 events and 878,535 P, Pn, pP, sP, and PcP arrivals recorded at 4606 stations. Relocated epicenters are an average of 16 km from bulletin locations. The data set included events that are known to an accuracy of 1 km (a.k.a. GT1) based on nonseismic information. The average distance between GT1 epicenters and our relocated epicenters is 5.6 km. For arrivals labeled P, Pn, and PcP, ˜92%, ˜90%, and 96% are properly labeled with probability >0.9, respectively. Incorrect phase labels are found to be erroneous at rates of 0.6%, 0.2%, 1.6%, and 2.5% for P, Pn, PcP, and depth phases (pP and sP), respectively. Labels found to be incorrect, but not erroneous, were reassigned to another phase label. P and Pn residual standard deviation with respect to ak135 travel times are dramatically reduced from 3.45 s to 1.01 s. The differences between travel time residuals for nearly reciprocal raypaths are significantly reduced from the input event locations, suggesting that Bayesloc relocation improves data set consistency. The reciprocity tests suggest that the dominant contribution to travel time residuals calculated from information provided in global bulletins is location and picks errors, not travel time prediction errors due to 3-D structure. Modeling the whole multiple-event system results in accurate locations and an internally consistent data set that is ideal for tomography and other travel time calibration studies. Simmons et al. (2011) (companion paper) use the Bayesloc-processed data set to develop a 3-D tomographic image, which further reduces residual standard deviation to 0.50 s. 7. Theoretical P-Wave Travel Times, Magnitude 6.7 Island of Hawaii, Hawaii, Sunday, October 15, 2006 at 17:07:49 UTC NSDL National Science Digital Library Earthquake Hazards Program This page from the USGS displays the predicted travel times of the P-Waves originating from the 6.7 magnitude earthquake that struck near Puako, HI on October 15th, 2006. There is a table of data as well as the map visualization. 8. P-wave tomography of crust and upper mantle under Southern California: Influence of topography of Moho discontinuity Microsoft Academic Search Jin-Li Huang; Da-Peng Zhao 2003-01-01 We use 146 422 P-wave arrival times from 6 347 local earthquakes recorded by the Southern California Seismic Network to determine\\u000a a detailed three-dimensional P-wave velocity structure at 0–35 km depth. We have taken into account the Moho depth variations,\\u000a which were obtained by seismological methods. Checkerboard tests suggest that our inversion results are reliable. Our models\\u000a provide new information 9. A self-adjoint arrival time operator inspired by measurement models E-print Network J. J. Halliwell; J. Evaeus; J. London; Y. Malik 2015-04-21 We introduce an arrival time operator which is self-adjoint and, unlike previously proposed arrival time operators, has a close link to simple measurement models. Its spectrum leads to an arrival time distribution which is a variant of the Kijowski distribution (a re-ordering of the current) in the large momentum regime but is proportional to the kinetic energy density in the small momentum regime, in agreement with measurement models. A brief derivation of the latter distribution is given. We make some simple observations about the physical reasons for self-adjointness, or its absence, in arrival time operators and also compare our operator with the dwell time operator. 10. Teleseismic P-wave Delay Time Tomography of the southern Superior Province and Midcontinent Rift System (MRS) Region NASA Astrophysics Data System (ADS) Bollmann, T. A.; van der Lee, S.; Frederiksen, A. W.; Wolin, E.; Aleqabi, G. I.; Revenaugh, J.; Wiens, D. A.; Darbyshire, F. A. 2014-12-01 The Superior Province Rifting Earthscope Experiment (SPREE) and the northern midwest footprint of USArray's Transportable Array recorded continuous ground motion for a period of 2.5 years. From around 400 M>5.5 teleseismic earthquakes recorded at 337 stations, we measured body wave delay times for 255 of these earthquakes. The P wave delays are accumulated over more than 45 thousand wave paths with turning points in the lower mantle. We combine these delay times with a similar number delay times used in previous tomographic studies of the study region. The latter delay times stem from fewer stations, including Polaris and CNSN stations, and nearly a thousand earthquakes. We combine these two sets of delay times to image the three-dimensional distribution of seismic velocity variations beneath the southern Superior Province and surrounding provinces. This combined data coverage is illustrated in the accompanying figure for a total number of 447 stations . The coverage and the combined delays form the best configuration yet to image the three-dimensional distribution of seismic P and S-wave velocity variations beneath the southern Superior and surrounding provinces. Closely spaced stations (~12 km) along and across the MRS provide higher resolving power for lithospheric structure beneath the rift system. Conforming to expectations that the entire region is underlain by thick, cool lithosphere, a mean delay of -.55 +/- .54 s. This is very similar to the mean delays -.6s +/- .37s measured for this region before 2012. Event corrections range from -.2 +/-.54 s and correlate with tectonics for 80% of the earthquakes. An inversion of these nearly one hundred thousand P and around thirty thousand S-wave delay times for high-resolution P and S-wave velocity structure, respectively, does not show structures that are obviously related to the crustal signature of the MRS. None of structures imaged, align with or have a similar shape to the high Mid-continent Gravity Anomaly (MGA). However, a low-velocity structure is imaged in the lithosphere just east of the MGA. 11. A COMPARISON OF COLLAPSING AND PRECISE ARRIVAL-TIME MAPPING OF MICROSEISMICITY SciTech Connect RUTLEDGE, JAMES T. [Los Alamos National Laboratory; JONES, ROB H. [Los Alamos National Laboratory 2007-01-05 In this paper they compare the improvements in microseismic location images obtained using precise arrival times with that obtained by the collapsing technique. They first collapse the initial locations for a hydraulic-fracture data set from the Carthage Cotton Valley gas field, they then use the precise-arrival-time locations as measure for the effectiveness of the collapsing. Finally, they examine the changes when applying collapsing to the precise-arrival-time locations. 12. A particle filtering approach for spatial arrival time tracking in ocean acoustics. PubMed Jain, Rashi; Michalopoulou, Zoi-Heleni 2011-06-01 The focus of this work is on arrival time and amplitude estimation from acoustic signals recorded at spatially separated hydrophones in the ocean. A particle filtering approach is developed that treats arrival times as "targets" and tracks their "location" across receivers, also modeling arrival time gradient. The method is evaluated via Monte Carlo simulations and is compared to a maximum likelihood estimator, which does not relate arrivals at neighboring receivers. The comparison demonstrates a significant advantage in using the particle filter. It is also shown that posterior probability density functions of times and amplitudes become readily available with particle filtering. PMID:21682358 13. Moho depth variations in the Taiwan orogen from joint inversion of seismic arrival time and Bouguer gravity data NASA Astrophysics Data System (ADS) Li, Zhiwei; Roecker, Steven; Kim, Kwanghee; Xu, Ya; Hao, Tianyao 2014-09-01 The joint inversion of different geophysical datasets is an effective means to reduce the non-uniqueness and improve the reliability of geophysical inversion. In this study, seismic arrival time and Bouguer gravity datasets are jointly inverted to obtain an image of 3-D velocity structures in the Taiwan orogen. The model obtained from joint inversion fits the arrival time observations at least as well as when inverted individually, and the gravity observations are much better fit when included in the inversion, implying a reduction in ambiguity by simultaneously modeling the disparate datasets. Moho depth variations estimated by the 3-D P wave velocity model suggest a maximum Moho depth of 56 km located beneath the Backbone Central Range, and the trend of the Moho is largely consistent with the topography of the Central Range with eastward, asymmetric crustal thickening. The root beneath the Central Range appears to be smaller in lateral extent than previously imaged, and the velocity gradients into the uppermost mantle are significantly higher. The lack of evidence for a significant amount of Eurasian crust in the mantle supports geodynamical models of accreted, rather than consumed, continental crust in a collisional environment. 14. Timing the Random and Anomalous Arrival of Particles in a Geiger Counter with GPS Devices ERIC Educational Resources Information Center Blanco, F.; La Rocca, P.; Riggi, F.; Riggi, S. 2008-01-01 The properties of the arrival time distribution of particles in a detector have been studied by the use of a small Geiger counter, with a GPS device to tag the event time. The experiment is intended to check the basic properties of the random arrival time distribution between successive events and to simulate the investigations carried out by… 15. Grid travel{time tracing: second{order method for the rst arrivals in smooth media * E-print Network Cerveny, Vlastislav Grid travel{time tracing: second{order method for the #12;rst arrivals in smooth media * Lud#20;ek the #12;rst{arrival travel times on a rectangular grid of points is proposed. Whereas the former "#12;nite is of the second{order accu- racy. It means that the relative propagation{velocity error of calculated travel time 16. Arrival timing in subadult and adult Black Redstart males: competition-dependent behaviour? Microsoft Academic Search L. Schwarzová; P. Štros; D. Frynta; R. Fuchs 2010-01-01 The different arrival times of 1-year-old and older males is a widely recognised phenomenon in most migrating passerines. The converse pattern, i.e. the yearlings arriving at the breeding grounds at the same time as adults, has been reported only exceptionally. Two hypotheses have been formulated to explain the delayed arrival of yearling males: investment reduction, and energetic constraint hypotheses, respectively. 17. Optimal convolutive filters for real-time detection and arrival time estimation of transient signals E-print Network Wichmann, Felix . In the case of transient signals, a filter has not only to detect the presence of a specific waveform, beamforming, Capon beamformer, linear filters, performance measure I. INTRODUCTION FOR detection of signals of simultaneously detecting the presence as well as estimating the arrival time of transient signals. This work 18. Localization of a noisy broadband surface target using time differences of multipath arrivals. PubMed Gebbie, John; Siderius, Martin; McCargar, Reid; Allen, John S; Pusey, Grant 2013-07-01 Previous studies [Tiemann et al., J. Acoust. Soc. Am. 120, 2355-2365 (2006)] have reported the localization of marine mammals in 3-D from their clicks using multipath arrivals. Bathymetric variations were advantageously used to predict multipath arrival times with a raytracer. These arrivals are directly discernible from the time series for impulsive sources, such as whale clicks, but extension of the method to continuous broadband sources presents additional complications. By pulse compressing noise emitted from a small boat using two hydrophones, the hyperbolic direct-arrival ambiguity can be refined in both range and bearing. Acoustic-derived results are validated with target GPS measurements. PMID:23862911 19. Passive source localization employing intersecting spherical surfaces from time-of-arrival differences Microsoft Academic Search H. C. SCHAU; A. Z. ROBINSON 1987-01-01 Problems associated with the use of intersecting hyperboloids for passive source localization from time-of-arrival difference signals are discussed. A closed-form solution for source location is presented given time-of-arrival difference measurements when the distance from the source to any arbitrary reference is unknown. 20. P wave travel times: Stability and change within the source volume of a M = 7.2 earthquake NASA Astrophysics Data System (ADS) Johnston, Arch C.; Wyss, M.; Koyanagi, R.; Habermann, R. E. 1982-08-01 The dense seismograph network on the south flank of Kilauea afforded a unique opportunity to study travel time changes as a function of space and time within the source volume of the Hawaii earthquake (Ms = 7.2) of 1975. Careful analysis of more than 600 teleseismic P arrivals from deep Fiji-Tonga earthquakes revealed the following: out of eight stations studied, six showed constant travel times to within ±0.03 s for up to 10 years with the exception of some small changes of about 0.03 s at the time of the main shock. One station, AHU, showed a highly significant and unique travel time decrease by 0.13 s during 1971/1972. At the beginning of this velocity anomaly a southwest rift intrusion caused closure of surface cracks associated with normal faults located near the station AHU. Also, geodetic measurements revealed that between August and October 1971 compressive strain of 4×10-5 was accumulated perpendicular to the southwest rift in the area of AHU. We conclude that these data show for the first time that in situ velocity increases occur due to the closure of cracks by tectonic forces. The AHU residuals returned to normal approximately at the time of a major earthquake swarm on the fault zone near AHU, during which surface cracks were observed to have opened again. This travel time decrease was corroborated by residuals from Novaya Zemlya explosions, but highfrequency local signals did not show it. Assuming that the stress sensitivity of the velocity was similar to that found by Reasenberg and Aki (1974), we have interpreted the teleseismic residual change at AHU as due to a P velocity increase of about 10% in the top 3.5±1.5-km of the crust. The only station, WHA, which showed a large (0.2 s) and extended (1972 to 1975) travel time increase was located only 4-km from the main shock epicenter. We interpret this velocity decrease as a precursor to the 1975 main shock, and we hypothesize that a process reverse from that at AHU caused this anomaly by first opening and then closing cracks in the crust below WHA. Both of these velocity anomalies were extremely localized in crustal volumes of dimensions of about 5±3-km. 1. Incorporating fault zone head wave and direct wave secondary arrival times into seismic tomography: Application at Parkfield, California NASA Astrophysics Data System (ADS) Bennington, N. L.; Thurber, C. H.; Zhang, H.; Peng, Z.; Zhao, P. 2011-12-01 Large crustal faults such as the San Andreas fault (SAF) often juxtapose rocks of significantly different elastic properties, resulting in well-defined bimaterial interfaces. A sharp material contrast across the fault interface is expected to generate fault zone head waves (FZHW's) that spend a large portion of their propagation paths refracting along the bimaterial interface (Ben-Zion 1989, 1990; Ben-Zion & Aki 1990). Because of this FZHW's provide a high-resolution tool for imaging the velocity contrast across the fault. Recently, Zhao et al. (2010) systematically analyzed large data sets of near-fault waveforms recorded by several permanent and temporary seismic networks along the Parkfield section of the SAF. The local-scale tomography study of Zhang et al. (2009) for a roughly 10 km3 volume centered on SAFOD and the more regional-scale study of Thurber et al. (2006) for a 130 km x 120 km x 20 km volume centered on the 2004 Parkfield earthquake rupture provide what are probably the best 3D images of the seismic velocity structure of the area. The former shows a low velocity zone associated with the SAF extending to significant depth, and both image the well-known velocity contrast across the fault. Seismic tomography generally uses just first P and/or S arrivals because of the relative simplicity of phase picking and ray tracing. Adding secondary arrivals such as FZHW's, however, can enhance the resolution of structure and strengthen constraints on earthquake locations and focal mechanisms. We present a model of 3D velocity structure for the Parkfield region that utilizes a combination of arrival times for FZHW's and the associated direct-wave secondary arrivals as well as existing P-wave arrival time data. The resulting image provides a higher-resolution model of the SAF at depth than previously published models. In addition, we plan to measure polarizations of the direct P and S waves and FZHW's and incorporate the data into our updated velocity tomography/relocation inversion. Through these efforts, we hope to refine the 3D tomographic image of seismic velocity structure and the complex geometry of the active fault strands near SAFOD and along the Parkfield rupture zone. 2. The prediction of bus arrival time using Automatic Vehicle Location Systems data E-print Network Jeong, Ran Hee 2005-02-17 is required. In addition to the prediction interval of bus arrival time, the probability that a given bus is on time was calculated. The probability density function of schedule adherence seemed to be the gamma distribution or the normal distribution... 3. Effect of time window length for maximum amplitude estimation on P wave magnitude: application for Earthquake Early Warning Microsoft Academic Search M. Hoshiba; K. Iwakiri; K. Ohtake 2009-01-01 Earthquake early warning, EEW, aims at issuing the warning of strong ground shaking before its arrival by analyzing seismic waveform data obtained near the hypocenter. Rapid estimation is important as well as precise anticipation of strong shaking. At present, Japan Meteorological Agency (JMA) anticipates the strong shaking using magnitude, attenuation relation and site amplification factors, and the anticipation is performed 4. Early Time Points Perfusion Imaging: Relative Time of Arrival, Maximum Derivatives and Fractional Derivatives PubMed Central Kwong, Kenneth K.; Wu, Ona; Chan, Suk-Tak; Nelissen, Koen; Kholodov, Mykhaylo; Chesler, David A. 2011-01-01 Time of arrival (TOA) of a bolus of contrast agent to the tissue voxel is a reference time point critical for the Early Time Points Perfusion Imaging Method (ET) to make relative cerebral blood flow (rCBF) maps. Due to the low contrast to noise (CNR) condition at TOA, other useful reference time points known as relative time of arrival data points (rTOA) are investigated. Candidate rTOA's include the time to reach the maximum derivative, the maximum second derivative, and the maximum fractional derivative. Each rTOA retains the same relative time distance from TOA for all tissue flow levels provided that ET's basic assumption is met, namely, no contrast agent has a chance to leave the tissue before the time of rTOA. The ET's framework insures that rCBF estimates by different orders of the derivative are theoretically equivalent to each other and monkey perfusion imaging results supported the theory. In rCBF estimation, maximum values of higher order fractional derivatives may be used to replace the maximum derivative which runs a higher risk of violating ET's assumption. Using the maximum values of the derivative of orders ranging from 1 to 1.5 to 2, estimated rCBF results were found to demonstrate a gray-white matter ratio of approximately 3, a number consistent with flow ratio reported in the literature. PMID:21600995 5. A Comparison of Waterflood Management Using Arrival Time Optimization and NPV Optimization E-print Network Tao, Qing 2011-02-22 allocation to the injectors and producers. Through optimal rate control, we can manage the propagation of the flood front, delay water breakthrough at the producers and also increase the sweep and hence, the recovery efficiency. The arrival time optimization... 6. The Quantum-Classical Comparison of the Arrival Time Distribution through the Probability Current E-print Network Md. Manirul Ali; A. S. Majumdar; Alok Kumar Pan 2006-12-22 We consider the arrival time distribution defined through the quantum probability current for a Gaussian wave packet representing free particles in quantum mechanics in order to explore the issue of the classical limit of arrival time. We formulate the classical analogue of the arrival time distribution for an ensemble of free particles represented by a phase space distribution function evolving under the classical Liouville's equation. The classical probability current so constructed matches with the quantum probability current in the limit of minimum uncertainty. Further, it is possible to show in general that smooth transitions from the quantum mechanical probability current and the mean arrival time to their respective classical values are obtained in the limit of large mass of the particles. 7. A review of the decoherent histories approach to the arrival time problem in quantum theory E-print Network James M Yearsley 2010-12-12 We review recent progress in understanding the arrival time problem in quantum mechanics, from the point of view of the decoherent histories approach to quantum theory. We begin by discussing the arrival time problem, focussing in particular on the role of the probability current in the expected classical solution. After a brief introduction to decoherent histories we review the use of complex potentials in the construction of appropriate class operators. We then discuss the arrival time problem for a particle coupled to an environment, and review how the arrival time probability can be expressed in terms of a POVM in this case. We turn finally to the question of decoherence of the corresponding histories, and we show that this can be achieved for simple states in the case of a free particle, and for general states for a particle coupled to an environment. 8. Arrival-time fluctuations of coherent reflections from surface gravity water waves. PubMed Badiey, Mohsen; Eickmeier, Justin; Song, Aijun 2014-05-01 Arrival time fluctuations of coherent reflections from surface gravity waves are examined. A two-dimensional ray model with an evolving rough sea surface is used to explain the mechanism and formation of the deterministic striation patterns due to the surface reflection. Arrival time predictions from the ray model match qualitatively well with the measurements from bidirectional acoustic transmissions in a water depth of 100?m. PMID:24815293 9. The prediction of bus arrival time using Automatic Vehicle Location Systems data E-print Network Jeong, Ran Hee 2005-02-17 their transit vehicles in real-time. The need for the model or technique to predict transit travel time using AVL data is increasing. While some research on this topic has been conducted, it has been shown that more research on this topic is required.... The objectives of this research were 1) to develop and apply a model to predict bus arrival time using AVL data, 2) to identify the prediction interval of bus arrival time and the probabilty of a bus being on time. In this research, the travel time prediction... 10. Mapping P-wave crustal structure using deformable-layer tomography in Southern California Microsoft Academic Search Li Li 2007-01-01 P-wave first arrival time data from earthquakes and surface seismic data have been used to map the crustal velocity structure in southern California. The combined data result in a dense and highly non-uniform ray-path distribution in the study area. Moho depths obtained from previous published studies have been used in the tomographic inversions to improve the lower crust portion of 11. Three-dimensional P-wave velocity structure of Mt. Etna, Italy Microsoft Academic Search A. Villaseñor; H. M. Benz; L. Filippi; G. De Luca; R. Scarpa; G. Patanè; S. Vinciguerra 1998-01-01 The three-dimensional P-wave velocity structure of Mt. Etna is determined to depths of 15 km by tomographic inversion of first arrival times from local earthquakes recorded by a network of 29 permanent and temporary seismographs. Results show a near-vertical low-velocity zone that extends from beneath the central craters to a depth of 10 km. This low-velocity region is coincident with 12. Scaling Behavior of the First Arrival Time of a Random-Walking Magnetic Domain SciTech Connect Im, M.-Y.; Lee, S.-H.; Kim, D.-H.; Fischer, P.; Shin, S.-C. 2008-02-04 We report a universal scaling behavior of the first arrival time of a traveling magnetic domain wall into a finite space-time observation window of a magneto-optical microscope enabling direct visualization of a Barkhausen avalanche in real time. The first arrival time of the traveling magnetic domain wall exhibits a nontrivial fluctuation and its statistical distribution is described by universal power-law scaling with scaling exponents of 1.34 {+-} 0.07 for CoCr and CoCrPt films, despite their quite different domain evolution patterns. Numerical simulation of the first arrival time with an assumption that the magnetic domain wall traveled as a random walker well matches our experimentally observed scaling behavior, providing an experimental support for the random-walking model of traveling magnetic domain walls. 13. Grid travel{time tracing: second{order method for the rst arrivals in smooth media E-print Network Cerveny, Vlastislav Grid travel{time tracing: second{order method for the #12;rst arrivals in smooth media Lud#20;ek{order accuracy. This means that the error of the calculated travel time is proportional to the second power presented for the appropriate evaluation of the errors of calculated travel times to check their accuracy 14. Continuous measurement of the arrival times of x-ray photon sequence SciTech Connect Yan Qiurong; Sheng Lizhi [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences 710119, Xi'an (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhao Baosheng; Liu Yong'an [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences 710119, Xi'an (China) 2011-05-15 In order to record x-ray pulse profile for x-ray pulsar-based navigation and timing, this paper presents a continuous, high-precision method for measuring arrival times of photon sequence with a common starting point. In this method, a high stability atomic clock is counted to measure the coarse time of arrival photon. A high resolution time-to-digital converter is used to measure the fine time of arrival photon. The coarse times and the fine times are recorded continuously and then transferred to computer memory by way of memory switch. The pulse profile is obtained by a special data processing method. A special circuit was developed and a low-level x-ray pulse profile measurement experiment system was setup. The arrival times of x-ray photon sequence can be consecutively recorded with a time resolution of 500 ps and the profile of x-ray pulse was constructed. The data also can be used for analysis by many other methods, such as statistical distribution of photon events per time interval, statistical distribution of time interval between two photon events, photon counting histogram, autocorrelation and higher order autocorrelation. 15. Multichannel deconvolution of p waves at seismic arrays and three-component stations. Annual report, 1 October 1985-1 October 1986 SciTech Connect Der, Z.A.; Lees, A.C.; Shumway, R.H.; McElfresh, T.W.; Marshall, M.E. 1986-10-30 The results of a new multichannel method, applied to array recordings and three-component station networks for teleseismic P waves, are presented and interpreted in terms of possible surface reflections and other arrivals from the Nevada Test Site (NTS), Novaya Zemlya, and Eastern Kazakh Test Site (EKTS) nuclear explosions. The deconvolution method utilizes the well known fact that P-wave spectra can be decomposed into source and receiver spectral factors. The source functions obtained in the deconvolution process provide a better picture of the nature of explosion source time functions and, in particular, of the presence or lack of secondary arrivals following the P wave such as pP or spall. The presence of such secondary arrivals and their effects on the first cycle of the P wave are very important in yield estimation. For most events at the eastern part of EKTS the source time functions appear to contain a pP arrival but they also show later, unexplained arrivals and other complexities. At other test sites often there are no clearly identifiable pP phases in the deconvolved traces. Joint deconvolution of central EKTS data using all AWRE arrays indicated strong azimuthal asymmetries in the body-wave radiation. Deconvolutions of NTS events were considerably degraded by the limited signal bandwidth due to strong mantle attenuation under this test site. The site functions are also complex in most cases. Site and source effects contribute about equally to the energy observed in the P codas of the events analyzed. 16. Using Time-Varying Tolls to Optimize Truck Arrivals at Ports Xiaoming Chen E-print Network Zhou, Xuesong between truck turn times and crane availability/deployment at terminal yards, Huynh (2005) developed a simulation-based framework to model detailed movements of trucks and yard cranes. By further combiningUsing Time-Varying Tolls to Optimize Truck Arrivals at Ports Xiaoming Chen Department of Civil 17. Idle and inter-arrival time statistics in public access mobile radio (PAMR) systems Microsoft Academic Search Francisco Barceló; Sergio Bueno 1997-01-01 The statistics of the message arrivals to a PAMR trunked system are investigated. The tools used to perform the statistical analysis have been previously used in similar works and are extremely simple. First, the probability density functions are fitted to the channel idle time (time between the end of a message and the beginning of the next one on the 18. Changes in the timing of departure and arrival of Irish migrant waterbirds. PubMed Donnelly, Alison; Geyer, Heather; Yu, Rong 2015-01-01 There have been many recent reports across Europe and North America of a change in the timing of arrival and departure of a range of migrant bird species to their breeding grounds. These studies have focused primarily on passerine birds and climate warming has been found to be one of the main drivers of earlier arrival and departure in spring. In Ireland, rising spring temperature has been shown to result in the earlier arrival of sub-Saharan passerine species and the early departure of the Whooper Swan. In order to investigate changes in spring arrival and departure dates of waterbirds to Ireland, we extracted latest dates as an indicator of the timing of departure of winter visitors (24 species) and earliest dates as an indicator of the timing of arrival of spring/summer migrants (2 species) from BirdWatch Ireland's East Coast Bird reports (1980-2003). Three of the winter visitors showed evidence of later departure and one of earlier departure whereas one of the spring/summer visitors showed evidence of earlier arrival. In order to determine any influence of local temperature on these trends, we analysed data from two synoptic weather stations within the study area and found that spring (average February, March and April) air temperature significantly (P < 0.05) increased at a rate of 0.03 °C per year, which was strongly correlated with changes in latest and earliest records. We also tested the sensitivity of bird departure/arrival to temperature and found that Northern Pintail would leave 10 days earlier in response to a 1 °C increase in spring temperature. In addition, we investigated the impact of a large-scale circulation pattern, the North Atlantic Oscillation (NAO), on the timing of arrival and departure which correlated with both advances and delays in departure and arrival. We conclude that the impact of climate change on earliest and latest records of these birds is, as expected, species specific and that local temperature had less of an influence than large-scale circulation patterns. PMID:25653907 19. Validation of a priori CME arrival predictions made using real-time heliospheric imager observations NASA Astrophysics Data System (ADS) Tucker-Hood, Kimberley; Scott, Chris; Owens, Mathew; Jackson, David; Barnard, Luke; Davies, Jackie A.; Crothers, Steve; Lintott, Chris; Simpson, Robert; Savani, Neel P.; Wilkinson, J.; Harder, B.; Eriksson, G. M.; L Baeten, E. M.; Wan Wah, Lily Lau 2015-01-01 Between December 2010 and March 2013, volunteers for the Solar Stormwatch (SSW) Citizen Science project have identified and analyzed coronal mass ejections (CMEs) in the near real-time Solar Terrestrial Relations Observatory Heliospheric Imager observations, in order to make "Fearless Forecasts" of CME arrival times and speeds at Earth. Of the 60 predictions of Earth-directed CMEs, 20 resulted in an identifiable Interplanetary CME (ICME) at Earth within 1.5-6 days, with an average error in predicted transit time of 22 h, and average transit time of 82.3 h. The average error in predicting arrival speed is 151 km s-1, with an average arrival speed of 425km s-1. In the same time period, there were 44 CMEs for which there are no corresponding SSW predictions, and there were 600 days on which there was neither a CME predicted nor observed. A number of metrics show that the SSW predictions do have useful forecast skill; however, there is still much room for improvement. We investigate potential improvements by using SSW inputs in three models of ICME propagation: two of constant acceleration and one of aerodynamic drag. We find that taking account of interplanetary acceleration can improve the average errors of transit time to 19 h and arrival speed to 77 km s-1. 20. Real-time Upstream Monitoring System: Predicting interplanetary shock arrivals using energetic particle data from ACE NASA Astrophysics Data System (ADS) Donegan, M. M.; Vandegriff, J.; Ho, G. C.; Wagstaff, K. L. 2004-05-01 We have created a system for predicting the arrival times at Earth of interplanetary (IP) shocks that originate at the Sun. Our prediction algorithm uses the real-time data stream from the Electron, Proton, and Alpha Monitor (EPAM) instrument on NASA's Advanced Composition Explorer (ACE) spacecraft. Most IP shocks are accompanied by locally accelerated energetic storm particle (ESP) events; signatures of ESP events can be used to predict the arrival of IP shocks. We have previously reported on the development and implementation of an algorithm to forecast the arrival of IP shocks. This prediction capability is combined with a web-based system that uses real-time ACE/EPAM data provided by the NOAA Space Environment Center (http://sd-www.jhuapl.edu/UPOS/RISP/index.html.) The most recent ACE data is continually processed and when an event is approaching, predictions of shock arrival time are updated every five minutes. Tests on the algorithm show an average error of ~9 hours for predictions made 24 hours before the shock arrival and ~5 hours when the shock is 12 hours away. This can provide significant lead-time and deliver critical information to mission planners, satellite operations controllers, and scientists. As of February 4, 2004, the ACE real-time stream has been switched to include data from another detector on EPAM. We are now processing the new real-time data stream and have made improvements to our neural network based on this data. In this paper, we report prediction results from this new network. 1. Intrinsic and attenuative dispersion characteristics of direct P-waves in and near the source area of the 1999 M W 7.6 Chi-Chi, Taiwan, earth- quake before and after the mainshock Microsoft Academic Search Xiqiang Liu; Chauhuei Chen; Yanwen Zhou; Junhao Qu 2009-01-01 Based on the measurement of the arrival time of maxima magnitude from band-pass filtering signals which were determined using\\u000a a new Morlet wavelet multiple-filter method, we develop a method for measuring intrinsic and attenuative dispersion of the\\u000a first cycle direct P-wave. We determine relative group delays of spectral components of direct P-waves for 984 ray paths from\\u000a SML and ALS 2. Multiband Time-of-Arrival Positioning Technique for Cognitive Radio Systems E-print Network Gesbert, David Multiband Time-of-Arrival Positioning Technique for Cognitive Radio Systems Robin R. Thomas, Bassem.knopp}@eurecom.fr Abstract--Accurate information regarding a cognitive radio user's location and environment can enhance the adaptive and spectral awareness capabilities of cognitive radio systems. In this paper, a single 3. Optimal Time Advance In Terminal Area Arrivals: Throughput vs. Fuel Savings NASA Technical Reports Server (NTRS) Sadovsky, Alexander V .; Swenson, Harry N.; Haskell, William B.; Rakas, Jasenka 2011-01-01 The current operational practice in scheduling air traffic arriving at an airport is to adjust flight schedules by delay, i.e. a postponement of an aircrafts arrival at a scheduled location, to manage safely the FAA-mandated separation constraints between aircraft. To meet the observed and forecast growth in traffic demand, however, the practice of time advance (speeding up an aircraft toward a scheduled location) is envisioned for future operations as a practice additional to delay. Time advance has two potential advantages. The first is the capability to minimize, or at least reduce, the excess separation (the distances between pairs of aircraft immediately in-trail) and thereby to increase the throughput of the arriving traffic. The second is to reduce the total traffic delay when the traffic sample is below saturation density. A cost associated with time advance is the fuel expenditure required by an aircraft to speed up. We present an optimal control model of air traffic arriving in a terminal area and solve it using the Pontryagin Maximum Principle. The admissible controls allow time advance, as well as delay, some of the way. The cost function reflects the trade-off between minimizing two competing objectives: excess separation (negatively correlated with throughput) and fuel burn. A number of instances are solved using three different methods, to demonstrate consistency of solutions. 4. Instate Travel Are departure and arrival times included on the travel expense statement? E-print Network Arnold, Jonathan Instate Travel Are departure and arrival times included on the travel expense statement? Is expense attached? For overnight travel, are per diem rates on the day of departure and day of return listed at 75 utilized a personal vehicle for travel and departed from or returned to his/her personal residence 5. The Use of Packet Inter-Arrival Times for Investigating Unsolicited Internet Traffic Microsoft Academic Search Jacob Zimmermann; Andrew Clark; George M. Mohay; Fabien Pouget; Marc Dacier 2005-01-01 Monitoring the Internet reveals incessant activity, that has been referred to as background radiation. In this paper, we propose an original approach that makes use of packet inter-arrival times, or IATs, to analyse and identify such abnormal or unexpected network activity. Our study exploits a large set of data collected on a distributed network of honeypots during more than six 6. Estimates of exposure rates and fallout arrival times near the Nevada Test Site Microsoft Academic Search Carol B. Thompson 1990-01-01 One of the tasks of the Off-Site Radiation Exposure Review Project (ORERP) was to estimate doses to individuals resulting from exposure to fallout from nuclear testing at the Nevada Test Site (NTS). Dose estimates are based on estimates of the exposure rate 12 h post-detonation (H + 12) and the time of fallout arrival from events producing discernible fallout at 7. Time of Arrival Estimation for WLAN Indoor Positioning Systems using Matrix Pencil Super Resolution Algorithm Microsoft Academic Search Ali AASSIE ALI; A. S. OMAR The accuracy of prediction of time of arrival (TOA) in wireless local area networks (WLAN) is the most important parameter for indoor positioning systems. This paper presents the application of super resolution matrix pencil (MP) algorithm for TOA estimation for indoor positioning application. Also it presents the results of frequency sweep measurements of indoor channel for the WLAN IEEE 801.11 8. PARTICLE SWARM OPTIMIZATION FOR TIME-DIFFERENCE-OF-ARRIVAL BASED LOCALIZATION E-print Network So, Hing-Cheung swarm optimization (PSO), an evolutionary search algorithm, to provide a robust and accurate solutionPARTICLE SWARM OPTIMIZATION FOR TIME-DIFFERENCE-OF-ARRIVAL BASED LOCALIZATION Kenneth W. K. Lui and broadly applied in many fields. In this paper, particle swarm optimization (PSO) is employed 9. Accurate seismic phase identification and arrival time picking of glacial icequakes NASA Astrophysics Data System (ADS) Jones, G. A.; Doyle, S. H.; Dow, C.; Kulessa, B.; Hubbard, A. 2010-12-01 A catastrophic lake drainage event was monitored continuously using an array of 6, 4.5 Hz 3 component geophones in the Russell Glacier catchment, Western Greenland. Many thousands of events and arrival time phases (e.g., P- or S-wave) were recorded, often with events occurring simultaneously but at different locations. In addition, different styles of seismic events were identified from 'classical' tectonic earthquakes to tremors usually observed in volcanic regions. The presence of such a diverse and large dataset provides insight into the complex system of lake drainage. One of the most fundamental steps in seismology is the accurate identification of a seismic event and its associated arrival times. However, the collection of such a large and complex dataset makes the manual identification of a seismic event and picking of the arrival time phases time consuming with variable results. To overcome the issues of consistency and manpower, a number of different methods have been developed including short-term and long-term averages, spectrograms, wavelets, polarisation analyses, higher order statistics and auto-regressive techniques. Here we propose an automated procedure which establishes the phase type and accurately determines the arrival times. The procedure combines a number of different automated methods to achieve this, and is applied to the recently acquired lake drainage data. Accurate identification of events and their arrival time phases are the first steps in gaining a greater understanding of the extent of the deformation and the mechanism of such drainage events. A good knowledge of the propagation pathway of lake drainage meltwater through a glacier will have significant consequences for interpretation of glacial and ice sheet dynamics. 10. Erratum: Operational time of arrival in quantum phase space [Phys. Rev. A 60, 2689 (1999) NASA Astrophysics Data System (ADS) Kocha?ski, Piotr; Wódkiewicz, Krzysztof 2000-02-01 An operational time of arrival is introduced using a realistic position and momentum measurement scheme. The phase space measurement involves the dynamics of a quantum particle probed by a measuring device. For such a measurement an operational positive operator valued measure in phase space is introduced and investigated. In such an operational formalism a quantum mechanical time operator is constructed and analyzed. A phase space time and energy uncertainty relation is derived. 11. Techniques for measuring arrival times of pulsar signals 1: DSN observations from 1968 to 1980 NASA Technical Reports Server (NTRS) Downs, G. S.; Reichley, P. E. 1980-01-01 Techniques used in the ground based observations of pulsars are described, many of them applicable in a navigation scheme. The arrival times of the pulses intercepting Earth are measured at time intervals from a few days to a few months. Low noise, wide band receivers, amplify signals intercepted by 26 m, 34, and 64 m antennas. Digital recordings of total received signal power versus time are cross correlated with the appropriate pulse template. 12. Monitoring molecular interactions using photon arrival-time interval distribution analysis DOEpatents Laurence, Ted A. (Livermore, CA); Weiss, Shimon (Los Angels, CA) 2009-10-06 A method for analyzing/monitoring the properties of species that are labeled with fluorophores. A detector is used to detect photons emitted from species that are labeled with one or more fluorophores and located in a confocal detection volume. The arrival time of each of the photons is determined. The interval of time between various photon pairs is then determined to provide photon pair intervals. The number of photons that have arrival times within the photon pair intervals is also determined. The photon pair intervals are then used in combination with the corresponding counts of intervening photons to analyze properties and interactions of the molecules including brightness, concentration, coincidence and transit time. The method can be used for analyzing single photon streams and multiple photon streams. 13. Time-of-arrival estimation for E-OTD location in GERAN Microsoft Academic Search Sven Fischer; Ari Kangas 2001-01-01 In this paper, the problem of time-of-arrival (TOA) estimation for E-OTD location in a GSM\\/EDGE Radio Access Network (GERAN) is described. To increase the number of available bursts for TOA estimation (and therefore increase the accuracy), the mobile can use bursts from all time slots. However, this requires that the TOA estimation algorithm is able to handle GMSK and 8PSK 14. A Comparison of Center/TRACON Automation System and Airline Time of Arrival Predictions NASA Technical Reports Server (NTRS) Heere, Karen R.; Zelenka, Richard E. 2000-01-01 Benefits from information sharing between an air traffic service provider and a major air carrier are evaluated. Aircraft arrival time schedules generated by the NASA/FAA Center/TRACON Automation System (CTAS) were provided to the American Airlines System Operations Control Center in Fort Worth, Texas, during a field trial of a specialized CTAS display. A statistical analysis indicates that the CTAS schedules, based on aircraft trajectories predicted from real-time radar and weather data, are substantially more accurate than the traditional airline arrival time estimates, constructed from flight plans and en route crew updates. The improvement offered by CTAS is especially advantageous during periods of heavy traffic and substantial terminal area delay, allowing the airline to avoid large predictive errors with serious impact on the efficiency and profitability of flight operations. 15. HF (high-frequency) absolute time of arrival sensing. Interim report, September 1981-May 1985 SciTech Connect Rose, R.B. 1986-02-01 In late 1980 questions arose concerning whether the ionosphere was sufficiently stable to allow precisely measured time of arrival of skywave signals to be used for geolocation in the high-frequency (HF) band between 2 and 32 MHz. The chief limitation in the accuracy of this type of system is the amount of uncertainty in the ionospheric-height estimation and its temporal stability. Traditional ionospheric research resources did not address the issue in sufficient detail and time resolution to be of any assistance. In order to understand the exact nature of the ionospheric uncertainties and to quantify their extent, experimentation was proposed to sense the variation in the refraction height of the ionosphere as it relates to the time of arrival of the HF signal. The objective of this work was to determine the range of environmentally induced errors in a skywave Time Difference of Arrival (TDOA) measurement, thereby bounding the ultimate geolocation accuracy one could expect from this technique. The first experimental measurement system started operation in early 1981. This effort involved establishing a continuous absolute Time of Arrival (TOA) experiment over the one-hop midlatitude path between San Diego, California and Fort Collins, Colorado. The system is fully digital and stabilized with a cesium-beam standard. This work was supplemented with vertical incidence sounder data at both ends of the path, a collateral Doppler sensing system, and coincident satellite solar data. A fully annotated database was prepared and is maintained by the Naval Ocean Systems Center Advanced Propagation Forecasting System (PROPHET). 16. Cerebral arterial bolus arrival time is prolonged in multiple sclerosis and associated with disability. PubMed Paling, David; Thade Petersen, Esben; Tozer, Daniel J; Altmann, Daniel R; Wheeler-Kingshott, Claudia A M; Kapoor, Raju; Miller, David H; Golay, Xavier 2014-01-01 Alterations in the overall cerebral hemodynamics have been reported in multiple sclerosis (MS); however, their cause and significance is unknown. While potential venous causes have been examined, arterial causes have not. In this study, a multiple delay time arterial spin labeling magnetic resonance imaging sequence at 3T was used to quantify the arterial hemodynamic parameter bolus arrival time (BAT) and cerebral blood flow (CBF) in normal-appearing white matter (NAWM) and deep gray matter in 33 controls and 35 patients with relapsing-remitting MS. Bolus arrival time was prolonged in MS in NAWM (1.0±0.2 versus 0.9±0.2?seconds, P=0.031) and deep gray matter (0.90±0.18 versus 0.80±0.14?seconds, P=0.001) and CBF was increased in NAWM (14±4 versus 10±2?mL/100?g/min, P=0.001). Prolonged BAT in NAWM (P=0.042) and deep gray matter (P=0.01) were associated with higher expanded disability status score. This study demonstrates alteration in cerebral arterial hemodynamics in MS. One possible cause may be widespread inflammation. Bolus arrival time was longer in patients with greater disability independent of atrophy and T2 lesion load, suggesting alterations in cerebral arterial hemodynamics may be a marker of clinically relevant pathology. PMID:24045400 17. Cerebral arterial bolus arrival time is prolonged in multiple sclerosis and associated with disability PubMed Central Paling, David; Thade Petersen, Esben; Tozer, Daniel J; Altmann, Daniel R; Wheeler-Kingshott, Claudia AM; Kapoor, Raju; Miller, David H; Golay, Xavier 2014-01-01 Alterations in the overall cerebral hemodynamics have been reported in multiple sclerosis (MS); however, their cause and significance is unknown. While potential venous causes have been examined, arterial causes have not. In this study, a multiple delay time arterial spin labeling magnetic resonance imaging sequence at 3T was used to quantify the arterial hemodynamic parameter bolus arrival time (BAT) and cerebral blood flow (CBF) in normal-appearing white matter (NAWM) and deep gray matter in 33 controls and 35 patients with relapsing–remitting MS. Bolus arrival time was prolonged in MS in NAWM (1.0±0.2 versus 0.9±0.2?seconds, P=0.031) and deep gray matter (0.90±0.18 versus 0.80±0.14?seconds, P=0.001) and CBF was increased in NAWM (14±4 versus 10±2?mL/100?g/min, P=0.001). Prolonged BAT in NAWM (P=0.042) and deep gray matter (P=0.01) were associated with higher expanded disability status score. This study demonstrates alteration in cerebral arterial hemodynamics in MS. One possible cause may be widespread inflammation. Bolus arrival time was longer in patients with greater disability independent of atrophy and T2 lesion load, suggesting alterations in cerebral arterial hemodynamics may be a marker of clinically relevant pathology. PMID:24045400 18. AIMBAT: A Python/Matplotlib Tool for Measuring Teleseismic Arrival Times NASA Astrophysics Data System (ADS) Lou, X.; van der Lee, S.; Lloyd, S. 2013-12-01 Python is an open-source, platform-independent, and object-oriented scripting language. It became more popular in the seismologist community since the appearance of ObsPy (Beyreuther et al. 2010, Megies et al. 2011), which provides a powerful framework for seismic data access and processing. This study introduces a new Python-based tool named AIMBAT (Automated and Interactive Measurement of Body-wave Arrival Times) for measuring teleseismic body-wave arrival times on large-scale seismic event data (Lou et al. 2013). Compared to ObsPy, AIMBAT is a lighter tool that is more focused on a particular aspect of seismic data processing. It originates from the widely used MCCC (Multi-Channel Cross-Correlation) method developed by VanDecar and Crosson (1990). On top of the original MCCC procedure, AIMBAT is automated in initial phase picking and is interactive in quality control. The core cross-correlation function is implemented in Fortran to boost up performance in addition to Python. The GUI (graphical user interface) of AIMBAT depends on Matplotlib's GUI-neutral widgets and event-handling API. A number of sorting and (de)selecting options are designed to facilitate the quality control of seismograms. By using AIMBAT, both relative and absolute teleseismic body-wave arrival times are measured. AIMBAT significantly improves efficiency and quality of the measurements. User interaction is needed only to pick the target phase arrival and to set a time window on the array stack. The package is easy to install and use, open-source, and is publicly available. Graphical user interface of AIMBAT. 19. Crustal and upper mantle velocity structure beneath central Tibet by P-wave teleseismic tomography NASA Astrophysics Data System (ADS) Zhang, Heng; Zhao, Junmeng; Xu, Qiang 2012-09-01 A detailed 3-D P-wave velocity model beneath central Tibet was obtained using 26 741 arrival times from 1025 teleseismic events recorded by the portable stations of the Hi-CLIMB project. In the crustal correction, we consider both vertical and lateral velocity variations. Our teleseismic P-wave tomography result reveals that the Indian lithospheric mantle underthrusts no further than 32.5°N. In addition, the presence of low velocity anomalies under the Indus-Tsangpo suture suggests that subduction is not a simple and continuous process. We suggest that the delamination of Indian mantle lithosphere induces mantle upwelling beneath the rifts, which in turn created cracks or a break in the subducted plate. Moreover, the formation of active rifts near the profile is related to the mantle upwelling. 20. Kilometer-wave type III burst - Harmonic emission revealed by direction and time of arrival NASA Technical Reports Server (NTRS) Alvarez, H.; Haddock, F. T.; Potter, W. H. 1974-01-01 A type III solar burst was observed at seven frequencies between 3.5 MHz and 80 kHz by the Michigan experiment aboard the IMP-6 satellite. From the data burst direction of arrival as well as time of arrival can be determined. These quantities are predicted, using simple models whose parameters are varied to obtain a good fit to the observations. It is found that between 3.5 MHz and 230 kHz the observed radiation was emitted at the fundamental of the local plasma frequency, while below 230 kHz it was emitted at the second harmonic. The exciter particles that produced the burst onset and burst peak have velocities of 0.27 and 0.12, respectively, in units of the velocity of light. 1. Acute stroke: why do some patients arrive in time and others do not? PubMed Soomann, Maarja; Vibo, Riina; Kõrv, Janika 2015-08-01 The aim of this study was to evaluate which factors are associated with early hospital arrival and help-seeking delays in acute stroke. All consecutive eligible patients were interviewed face-to-face within 72?h of admission. Factors associated with early arrival were assessed by univariate and multivariate analysis. The data of 195 patients were analysed. The patients who first called the emergency medical services rather than the family physician arrived earlier (odds ratio 15.9, 95% confidence interval 3.23-78.3, P<0.01). Those who contacted the emergency medical services within 30?min of symptom onset were more likely to receive thrombolysis (odds ratio 6.9, 95% confidence interval 2.6-18.4, P<0.01). The most common reasons for delaying seeking help were the hope for spontaneous recovery and perceiving the elapsed time as insignificant. The patients who call their family physician lose valuable time and their chance for thrombolysis. Many patients probably neglect symptoms because of stroke itself and therefore do not act fast enough. PMID:25222429 2. Comparing seismic tomographic images from automatically- and manually-detected arrival times NASA Astrophysics Data System (ADS) Spallarossa, Daniele; Scafidi, Davide; Turino, Chiara; Ferretti, Gabriele; Viganò, Alfio 2013-04-01 In this work we compare local earthquake tomographic images obtained using arrival times detected by an automatic picking procedure and by an expert seismologist. For this purpose we select a reference dataset composed of 476 earthquakes occurred in the Trentino region (north-eastern Italy) in the period 1994-2007. Local magnitudes are comprised between 0.8 and 5.3. Original recordings are mainly from the Provincia Autonoma di Trento (PAT), and from other networks operating in the surrounding areas (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - INOGS; Istituto Nazionale di Geofisica e Vulcanologia - INGV; others available via the European Integrated Data Archive). The automatic picking of P and S phases is performed through a picker engine based on the Akaike information criterion (AIC). In particular, the proposed automatic phase picker includes: (i) envelope calculation, (ii) band-pass filtering, (iii) Akaike information criterion (AIC) detector for both P- and S-arrivals, (iv) checking for impulsive arrivals, (v) evaluation of expected S onset on the basis of a preliminary location derived from the P-arrival times, and (vi) quality assessment. Simultaneously, careful manual inspection by expert seismologists is applied to the same waveform dataset, to obtain manually-repicked phase readings. Both automatic and manual procedures generate a comparable amount of readings (about 6000 P- and 5000 S-phases). These data are used for the determination of two similar 3-D propagation models for the Trentino region, applying the SIMULPS code. In order to quantitatively estimate the difference of these two models we measure their discrepancies in terms of velocity at all grid points. The small differences observed among tomographic results allow us to demonstrate that the automatic picking engine adopted in this test can be used for reprocessing large amount of seismic recordings with the aim of perform a local tomographic study with an accuracy comparable to the one obtainable with a complete manual data revision. 3. A bias-free quantum random number generation using photon arrival time selectively E-print Network Jian-min Wang; Tian-yu Xie; Hong-fei Zhang; Dong-xu Yang; Chao Xie; Jian Wang 2015-05-20 We present a high-quality, bias-free quantum random number generator (QRNG) using photon arrival time selectively in accordance with the number of photon detection events within a sampling time interval in attenuated light. It is well showed in both theoretical analysis and experiments verification that this random number production method eliminates both bias and correlation perfectly without more post processing and the random number can clearly pass the standard randomness tests. We fulfill theoretical analysis and experimental verification of the method whose rate can reach up to 45Mbps. 4. Highly efficient arrival timing diagnostics for femtosecond X-ray and optical laser pulses NASA Astrophysics Data System (ADS) Sato, Takahiro; Togashi, Tadashi; Ogawa, Kanade; Katayama, Tetsuo; Inubushi, Yuichi; Tono, Kensuke; Yabashi, Makina 2015-01-01 We developed a diagnostic system for measuring the arrival timing between femtosecond X-ray free-electron laser (XFEL) and near-infrared laser pulses with high efficiency. The ultrafast change in optical transmittance induced by intense XFEL light was probed by a spatial decoding technique. For enhancing detection efficiency, we utilized an X-ray elliptical mirror that increases X-ray intensity by forming a line-focused profile. We found that the system is applicable to the timing diagnostics for 12 keV X-ray pulses with a pulse energy as small as 12 µJ. 5. Predicting Ambulance Time of Arrival to the Emergency Department Using Global Positioning System and Google Maps PubMed Central Fleischman, Ross J.; Lundquist, Mark; Jui, Jonathan; Newgard, Craig D.; Warden, Craig 2014-01-01 Objective To derive and validate a model that accurately predicts ambulance arrival time that could be implemented as a Google Maps web application. Methods This was a retrospective study of all scene transports in Multnomah County, Oregon, from January 1 through December 31, 2008. Scene and destination hospital addresses were converted to coordinates. ArcGIS Network Analyst was used to estimate transport times based on street network speed limits. We then created a linear regression model to improve the accuracy of these street network estimates using weather, patient characteristics, use of lights and sirens, daylight, and rush-hour intervals. The model was derived from a 50% sample and validated on the remainder. Significance of the covariates was determined by p < 0.05 for a t-test of the model coefficients. Accuracy was quantified by the proportion of estimates that were within 5 minutes of the actual transport times recorded by computer-aided dispatch. We then built a Google Maps-based web application to demonstrate application in real-world EMS operations. Results There were 48,308 included transports. Street network estimates of transport time were accurate within 5 minutes of actual transport time less than 16% of the time. Actual transport times were longer during daylight and rush-hour intervals and shorter with use of lights and sirens. Age under 18 years, gender, wet weather, and trauma system entry were not significant predictors of transport time. Our model predicted arrival time within 5 minutes 73% of the time. For lights and sirens transports, accuracy was within 5 minutes 77% of the time. Accuracy was identical in the validation dataset. Lights and sirens saved an average of 3.1 minutes for transports under 8.8 minutes, and 5.3 minutes for longer transports. Conclusions An estimate of transport time based only on a street network significantly underestimated transport times. A simple model incorporating few variables can predict ambulance time of arrival to the emergency department with good accuracy. This model could be linked to global positioning system data and an automated Google Maps web application to optimize emergency department resource use. Use of lights and sirens had a significant effect on transport times. PMID:23865736 6. Crustal parameters estimated from P-waves of earthquakes recorded at a small array NASA Astrophysics Data System (ADS) Murdock, James N.; Steppe, J. Alan 1980-09-01 The P-arrival times of local and regional earthquakes that are outside of a small network of seismometers can be used to interpret crustal parameters beneath the network by employing the time-term technique. Even when the estimate of the refractor velocity is poorly determined, useful estimates of the station time-terms can be made. The method is applied to a 20 km diameter network of eight seismic stations which was operated near Castaic, California, during the winter of 1972 73. The stations were located in sedimentary basins. Beneath the network, the sedimentary rocks of the basins are known to range from 1 to more than 4 km in thickness. Relative time-terms are estimated from P-waves assumed to be propagated by a refractor in the mid-crust, and again from P-waves propagated by a refractor in the upper basement. For the range of velocities reported by others, the two sets of time-terms are very similar. They suggest that both refractors dip to the southwest, and the geology also indicates that the basement dips in this direction. In addition, the P-wave velocity estimated for the refractor of mid-crustal depths, roughly 6.7 km/sec, agrees with values reported by others. Thus, even in this region of complicated geologic structure, the method appears to give realistic results. 7. Crustal parameters estimated from P-waves of earthquakes recorded at a small array USGS Publications Warehouse Murdock, J.N.; Steppe, J.A. 1980-01-01 The P-arrival times of local and regional earthquakes that are outside of a small network of seismometers can be used to interpret crustal parameters beneath the network by employing the time-term technique. Even when the estimate of the refractor velocity is poorly determined, useful estimates of the station time-terms can be made. The method is applied to a 20 km diameter network of eight seismic stations which was operated near Castaic, California, during the winter of 1972-73. The stations were located in sedimentary basins. Beneath the network, the sedimentary rocks of the basins are known to range from 1 to more than 4 km in thickness. Relative time-terms are estimated from P-waves assumed to be propagated by a refractor in the mid-crust, and again from P-waves propagated by a refractor in the upper basement. For the range of velocities reported by others, the two sets of time-terms are very similar. They suggest that both refractors dip to the southwest, and the geology also indicates that the basement dips in this direction. In addition, the P-wave velocity estimated for the refractor of mid-crustal depths, roughly 6.7 km/sec, agrees with values reported by others. Thus, even in this region of complicated geologic structure, the method appears to give realistic results. ?? 1980 Birkha??user Verlag. 8. Analytical arrival and persistence time distributions for flow thresholds in seasonally dry climates NASA Astrophysics Data System (ADS) Dralle, D.; Thompson, S. E. 2014-12-01 Seasonally dry ecosystems, which include Mediterranean, tropical monsoonal and tropical savannah climates, cover approximately 30% of the planet's land area and are globally significant biodiversity hotspots. Due to a highly variable climate, the streamflow available for ecosystems and ecosystems services in these regions is typified by large inter-annual variability. Methods to quantify this variability could shed light on stream ecosystem stress, particularly new stresses imposed by human activity or climate change. This study develops a probabilistic framework to examine controls on dry season flow characteristics in seasonally dry climates. Assuming a typical recession pattern, which is conditioned on an initial value that is sampled from the wet season flows [1,2], analytical PDFs for the arrival time of a given dry season flow threshold can be obtained. Below-flow-threshold persistence time distributions are computed as the difference between an (assumed) normally distributed dry season length and the mean flow threshold arrival time. A number of hypotheses are proposed to explain unexpected sources of variability in the empirical arrival time distributions. The ecologic implications of extended low flow persistence, such as the hydrologic fragmentation of lower order watersheds, are discussed. [1] Müller, M. F., D. N. Dralle, and S. E. Thompson (2014), Analytical model for flow duration curves in seasonally dry climates, Water Resour. Res., 50, doi:10.1002/2014WR015301 [2] Botter, G., A. Porporato, I. Rodriguez-Iturbe, and A. Rinaldo (2007), Basin-scale soil moisture dynamics and the probabilistic characterization of carrier hydrologic flows: Slow, leaching-prone components of the hydrologic response, Water Resour. Res., 43, W02417, doi:10.1029/2006WR005043 9. Time-of-arrival analysis applied to ELF/VLF wave generation experiments at HAARP NASA Astrophysics Data System (ADS) Moore, R. C.; Fujimaru, S. 2012-12-01 Time-of-arrival (TOA) analysis is applied to observations performed during ELF/VLF wave generation experiments at the High-frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska. In 2012, a variety of ELF/VLF wave generation techniques were employed to identify the dominant source altitude for each case. Observations were performed for beat-wave modulation, AM modulation, STF modulation, ICD modulation, and cubic frequency modulation, among others. For each of these cases, we identify the dominant ELF/VLF source altitude and compare the experimental results with theoretical HF heating predictions. 10. Processing advances for localization of beaked whales using time difference of arrival. PubMed Baggenstoss, Paul M 2013-06-01 This paper is concerned with the localization of clicking Blainville's beaked whales (Mesoplodon densirostris) using an array of widely spaced bottom-mounted hydrophones. A set of signal and data processing advances are presented that together make reliable tracking a possibility. These advances include a species-specific detector, elimination of spurious time-difference-of-arrival (TDOA) estimates, improved tracking of TDOA estimates, positive association of TDOA estimates using different hydrophone pairs, and joint localization of multiple whales. A key innovation in three of these advances is the principle of click-matching. The methods are demonstrated using real data. PMID:23742359 11. Ziv-Zakai bound on time-of-arrival estimation with statistical channel knowledge at the receiver E-print Network Dardari, Davide Time-of-arrival (TOA) based localization plays an important role due to the possibility to exploit the fine delay resolution property when wideband signals are adopted. This paper investigates lower bounds on TOA estimation ... 12. Comparative Study of Bunch Length And Arrival Time Measurements at FLASH SciTech Connect Schlarb, H.; Azima, A.; Dusterer, S.; Huning, M.; Knabbe, E.A.; Roehrs, M.; Rybnikov, V.; Schmidt, B.; Steffen, B.; /DESY; Ross, M.C.; /SLAC; Schmueser, P.; Winter, A.; /Hamburg U. 2007-04-16 Diagnostic devices to precisely measure the longitudinal electron beam profile and the bunch arrival time require elaborate new instrumentation techniques. At FLASH, two entirely different methods are used. The bunch profile can be determined with high precision by a transverse deflecting RF structure, but the method is disruptive and does not allow to monitor multiple bunches in a macro-pulse train. It is therefore complemented by two non-disruptive electrooptical devices, called EO and TEO. The EO setup uses a dedicated diagnostic laser synchronized to the machine RF. The longitudinal electron beam profile is encoded in the intensity profile of a chirped laser pulse and analyzed by looking at the spectral composition of the pulse. The second setup, TEO, utilizes the TiSa-based laser system used for pump-probe experiments. Here, the temporal electron shape is encoded into the spatial dimension of the laser pulse by an intersection angle between the laser and the electron beam at the EO-crystal. In this paper, we present a comparative study of bunch length and arrival time measurements performed simultaneously with all three experimental techniques. 13. Real-time Upstream Monitoring System (RUMS): Forecasting arrival times of interplanetary shocks using energetic particle data from ACE NASA Astrophysics Data System (ADS) Ho, G.; Donegan, M.; Vandegriff, J.; Wagstaff, K. We have created a system for predicting the arrival times at Earth of interplanetary (IP) shocks that originate at the Sun. This system is currently available on the web (http://sd-www.jhuapl.edu/UPOS/RISP/index.html) and runs in real-time. Input data to our prediction algorithm is energetic particle data from the Electron, Proton, and Alpha Monitor (EPAM) instrument on NASA's Advanced Composition Explorer (ACE) spacecraft. Real-time EPAM data is obtained from the National Oceanic and Atmospheric Administration (NOAA) Space Environment Center (SEC). Our algorithm operates in two stages. First it watches for a velocity dispersion signature (energetic ions show flux enhancement followed by subsequent enhancements in lower energies), which is commonly seen upstream of a large IP shock. Once a precursor signature has been detected, a pattern recognition algorithm is used to analyze the time series profile of the particle data and generate an estimate for the shock arrival time. Tests on the algorithm show an average error of roughly 9 hours for predictions made 24 hours before the shock arrival and roughly 5 hours when the shock is 12 hours away. This can provide significant lead-time and deliver critical information to mission planners, satellite operations controllers, and scientists. As of February 4, 2004, the ACE real-time stream has been switched to include data from another detector on EPAM. We are now processing the new real-time data stream and have made improvements to our algorithm based on this data. In this paper, we report prediction results from the updated algorithm. 14. 41 CFR 301-11.10 - Am I required to record departure/arrival dates and times on my travel claim? Code of Federal Regulations, 2013 CFR 2013-07-01 ...departure/arrival dates and times on my travel claim? 301-11.10...departure/arrival dates and times on my travel claim? You must record...record departure/arrival times, but you must annotate your travel claim when your travel... 15. 41 CFR 301-11.10 - Am I required to record departure/arrival dates and times on my travel claim? Code of Federal Regulations, 2014 CFR 2014-07-01 ...departure/arrival dates and times on my travel claim? 301-11.10...departure/arrival dates and times on my travel claim? You must record...record departure/arrival times, but you must annotate your travel claim when your travel... 16. 41 CFR 301-11.10 - Am I required to record departure/arrival dates and times on my travel claim? Code of Federal Regulations, 2012 CFR 2012-07-01 ...departure/arrival dates and times on my travel claim? 301-11.10...departure/arrival dates and times on my travel claim? You must record...record departure/arrival times, but you must annotate your travel claim when your travel... 17. Seismicity and arrival-time residuals from the Victoria Earthquake of June 9, 1980 SciTech Connect Wong, V.; Frez, J. 1981-01-01 Hypocenter distribution in space and time of the aftershock activity from the Victoria Earthquake of June 9, 1980 was studied. It was concluded that the main event excited aftershocks in several pre-existing nests at the northwest end of the Cerro Prieto Fault, but no significant activity occurred at the immediate neighborhood of the main event. The depth of the aftershocks increases with the distance from the northwest end of the fault and this feature might be related with the higher temperatures and the spreading center located between the ends of the Imperial and Cerro Prieto Faults. The significance of the arrival-times residuals for local and regional stations is discussed both for P and S-waves and the importance of obtaining station corrections is emphasized. The non-uniqueness in determining a structure which minimizes the residuals is illustrated. Two different structures which satisfy the local data are presented. 18. High Bandwidth Pickup Design for Bunch Arrival-time Monitors for Free-Electron Laser E-print Network Angelovski, Aleksandar; Hansli, Matthias; Penirschke, Andreas; Schnepp, Sascha M; Bousonville, Michael; Schlarb, Holger; Bock, Marie Kristin; Weiland, Thomas; Jakoby, Rolf 2012-01-01 In this paper, we present the design and realization of high bandwidth pickup electrodes with a cutoff frequency above 40 GHz. The proposed cone-shaped pickups are part of a bunch arrival-time monitor (BAM) designed for high (> 500 pC) and low (20 pC) bunch charge operation mode providing for a time resolution of less than 10 fs for both operation modes. The proposed design has a fast voltage response, low ringing, and a resonance-free spectrum. For assessing the influence of manufacturing tolerances on the performance of the pickups, an extensive tolerance study has been performed via numerical simulations. A non-hermetic model of the pickups was built for measurement and validation purposes. The measurement and simulation results are in good agreement and demonstrate the capability of the proposed pickup system to meet the given specifications. 19. Relaxing the closure assumption in single-season occupancy models: staggered arrival and departure times USGS Publications Warehouse Kendall, William L.; Hines, James E.; Nichols, James D.; Grant, Evan H. Campbell 2013-01-01 Occupancy statistical models that account for imperfect detection have proved very useful in several areas of ecology, including species distribution and spatial dynamics, disease ecology, and ecological responses to climate change. These models are based on the collection of multiple samples at each of a number of sites within a given season, during which it is assumed the species is either absent or present and available for detection while each sample is taken. However, for some species, individuals are only present or available for detection seasonally. We present a statistical model that relaxes the closure assumption within a season by permitting staggered entry and exit times for the species of interest at each site. Based on simulation, our open model eliminates bias in occupancy estimators and in some cases increases precision. The power to detect the violation of closure is high if detection probability is reasonably high. In addition to providing more robust estimation of occupancy, this model permits comparison of phenology across sites, species, or years, by modeling variation in arrival or departure probabilities. In a comparison of four species of amphibians in Maryland we found that two toad species arrived at breeding sites later in the season than a salamander and frog species, and departed from sites earlier. 20. Gluon fragmentation into P wave heavy quarkonium SciTech Connect Braaten, Eric; Yuan, Tzu Chiang 1994-03-01 The fragmentation functions for gluons to split into P-wave heavy quarkonium states are calculated to leading order in the QCD coupling constant. Long-distance effects are factored into two nonperturbative parameters: the derivative of the radial wavefunction at the origin and a second parameter related to the probability for a heavy-quark-antiquark pair that is produced in a color-octet S-wave state to form a color-singlet P-wave bound state. The fragmentation probabilities for a high transverse momentum gluon to split into the P-wave charmonium states \\chi_{c0}, \\chi_{c1}, and \\chi_{c2} are estimated to be 0.4 \\times 10^{-4}, 1.8 \\times 10^{-4}, and 2.4 \\times 10^{-4}, respectively. This fragmentation process may account for a significant fraction of the rate for the inclusive production of \\chi_{cJ} at large transverse momentum in p \\bar p colliders. 1. Spectral encoding method for measuring the relative arrival time between x-ray/optical pulses. PubMed Bionta, M R; Hartmann, N; Weaver, M; French, D; Nicholson, D J; Cryan, J P; Glownia, J M; Baker, K; Bostedt, C; Chollet, M; Ding, Y; Fritz, D M; Fry, A R; Kane, D J; Krzywinski, J; Lemke, H T; Messerschmidt, M; Schorb, S; Zhu, D; White, W E; Coffee, R N 2014-08-01 The advent of few femtosecond x-ray light sources brings promise of x-ray/optical pump-probe experiments that can measure chemical and structural changes in the 10-100 fs time regime. Widely distributed timing systems used at x-ray Free-Electron Laser facilities are typically limited to above 50 fs fwhm jitter in active x-ray/optical synchronization. The approach of single-shot timing measurements is used to sort results in the event processing stage. This has seen wide use to accommodate the insufficient precision of active stabilization schemes. In this article, we review the current technique for "measure-and-sort" at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The relative arrival time between an x-ray pulse and an optical pulse is measured near the experimental interaction region as a spectrally encoded cross-correlation signal. The cross-correlation provides a time-stamp for filter-and-sort algorithms used for real-time sorting. Sub-10 fs rms resolution is common in this technique, placing timing precision at the same scale as the duration of the shortest achievable x-ray pulses. PMID:25173255 2. Statistical analysis of inter-arrival times of rainfall events for Italian Sub-Alpine and Mediterranean areas NASA Astrophysics Data System (ADS) Agnese, C.; Baiamonte, G.; Cammalleri, C.; Cat Berro, D.; Ferraris, S.; Mercalli, L. 2012-09-01 In this work a set of time-series of inter-arrival times of rainfall events, at daily scale, was analysed, with the aim to verify the issue of increasing duration of dry periods. The set consists of 12 time-series recorded at rain gauges in 1926-2005, six of them belong to an Italian Sub-Alpine area (Piedmont) and six to a Mediterranean one (Sicily). In order to overcome the problem related to limited sample size for high values of inter-arrival times, the discrete probability polylog-series distribution was used to fit the empirical data from partial (20 yr) time-series. Moreover, a simple qualitative trend analysis was applied to some high quantiles of inter-arrival times as well as to the average extent of rain clusters. The preliminary analysis seems to confirm the issue of increasing duration of dry periods for both environments, which is limited to the "cold" season. 3. Constrained Optimization of Average Arrival Time via a Probabilistic Approach to Transport Reliability PubMed Central Namazi-Rad, Mohammad-Reza; Dunbar, Michelle; Ghaderi, Hadi; Mokhtarian, Payam 2015-01-01 To achieve greater transit-time reduction and improvement in reliability of transport services, there is an increasing need to assist transport planners in understanding the value of punctuality; i.e. the potential improvements, not only to service quality and the consumer but also to the actual profitability of the service. In order for this to be achieved, it is important to understand the network-specific aspects that affect both the ability to decrease transit-time, and the associated cost-benefit of doing so. In this paper, we outline a framework for evaluating the effectiveness of proposed changes to average transit-time, so as to determine the optimal choice of average arrival time subject to desired punctuality levels whilst simultaneously minimizing operational costs. We model the service transit-time variability using a truncated probability density function, and simultaneously compare the trade-off between potential gains and increased service costs, for several commonly employed cost-benefit functions of general form. We formulate this problem as a constrained optimization problem to determine the optimal choice of average transit time, so as to increase the level of service punctuality, whilst simultaneously ensuring a minimum level of cost-benefit to the service operator. PMID:25992902 4. Measuring pulse times of arrival from broad-band pulsar observations NASA Astrophysics Data System (ADS) Liu, K.; Desvignes, G.; Cognard, I.; Stappers, B. W.; Verbiest, J. P. W.; Lee, K. J.; Champion, D. J.; Kramer, M.; Freire, P. C. C.; Karuppusamy, R. 2014-10-01 In recent years, instrumentation enabling pulsar observations with unprecedentedly high fractional bandwidth has been under development which can be used to substantially improve the precision of pulsar timing experiments. The traditional template-matching method used to calculate pulse times of arrival (ToAs) may not function effectively on these broad-band data due to a variety of effects such as diffractive scintillation in the interstellar medium, profile variation as a function of frequency, dispersion measure (DM) evolution, and so forth. In this paper, we describe the channelized discrete Fourier transform method that can greatly mitigate the influence of the aforementioned effects when measuring ToAs from broad-band timing data. The method is tested on simulated data, and its potential in improving timing precision is shown. We further apply the method to PSR J1909-3744 data collected at the Nançay Radio Telescope with the Nançay Ultimate Pulsar Processing Instrument. We demonstrate removal of systematics due to the scintillation effect as well as improvement on ToA measurement uncertainties. Our method also determines temporal variations in DM, which are consistent with multichannel timing approaches used earlier. 5. Analysis of small intestinal transit and colon arrival times of non-disintegrating tablets administered in the fasted state. PubMed Pišlar, Mitja; Brelih, Hana; Mrhar, Aleš; Bogataj, Marija 2015-07-30 In this study individual data on tablet gastrointestinal transit times (i.e. gastric emptying, small intestinal transit, ileocecal junction residence, and colon arrival times) were obtained from literature in order to present and analyze their distributions and relationships. The influence of the time of food intake after tablet administration in fasted state on gastrointestinal transit times was additionally evaluated. There were 114 measurements from subjects who received the first meal at 4h after tablet administration. Approximately 32% of the tablets arrived into the colon before the meal intake at 4h. An evident increase in the frequency of colon arrival of tablets within 40min after the meal intake at 4h post-dose was observed, where approximately 39% of all tablets arrived into the colon. This is in accordance with findings described in literature where a meal ingested several hours post-dose accelerates tablet transit through the terminal ileum and shortens the transit through the small intestine. The median (min, max) of gastric emptying, small intestinal transit, and colon arrival times in the group where the first meal intake was at 4h post-dose is 35 (0,192), 215 (60,544), and 254 (117,604) minutes, respectively. The dependence of colon arrival times on gastric emptying times was described by the nonparametric regression curve, and compared with the presumed interval of colon arrival times, calculated by summation of observed gastric emptying times and frequently cited small intestinal transit time interval, i.e. 3-4h. For shorter gastric emptying times the trend of colon arrival times was within the presumed interval. At short gastric emptying times many observation points are also within the presumed interval since this interval coincides with short period after meal intake at 4h post-dose. Additionally, in numerous occasions relatively long ileocecal junction residence times were obtained, which may be important information from the point of view of drug absorption. The findings of gastrointestinal transit times are important and should be taken into consideration when predicting the in vivo performance of dosage forms after oral administration. PMID:25769525 6. Priority effects of time of arrival of plant functional groups override sowing interval or density effects: a grassland experiment. PubMed von Gillhaussen, Philipp; Rascher, Uwe; Jablonowski, Nicolai D; Plückers, Christine; Beierkuhnlein, Carl; Temperton, Vicky M 2014-01-01 Priority effects occur when species that arrive first in a habitat significantly affect the establishment, growth, or reproduction of species arriving later and thus affect functioning of communities. However, we know little about how the timing of arrival of functionally different species may alter structure and function during assembly. Even less is known about how plant density might interact with initial assembly. In a greenhouse experiment legumes, grasses or forbs were sown a number of weeks before the other two plant functional types were sown (PFT) in combination with a sowing density treatment. Legumes, grasses or non-legume forbs were sown first at three different density levels followed by sowing of the remaining PFTs after three or six-weeks. We found that the order of arrival of different plant functional types had a much stronger influence on aboveground productivity than sowing density or interval between the sowing events. The sowing of legumes before the other PFTs produced the highest aboveground biomass. The larger sowing interval led to higher asymmetric competition, with highest dominance of the PFT sown first. It seems that legumes were better able to get a head-start and be productive before the later groups arrived, but that their traits allowed for better subsequent establishment of non-legume PFTs. Our study indicates that the manipulation of the order of arrival can create priority effects which favour functional groups of plants differently and thus induce different assembly routes and affect community composition and functioning. PMID:24497995 7. Measurement of arrival time of particles in extensive air showers using TDC32 NASA Astrophysics Data System (ADS) Gupta, S. K.; Christiansen, J.; Hayashi, Y.; Jain, A.; Mohanty, P. K.; Ravindran, K. C.; Satyanarayana, B. 2013-04-01 Arrival time of particles in an extensive air shower (EAS) is a key physical parameter to determine its direction. EAS direction is useful for studies of anisotropy and composition of cosmic rays, and search for multi-TeV ?-rays sources. Accurate timing may be used to search exotic phenomena such as production of new particles at extremely high energies available during early stages of development of EAS and also for detecting sub-relativistic hadrons in EAS. Time to digital converters (TDCs) are used to perform this task. Traditional TDCs operate in the START-STOP mode with limited dynamic range and single-hit capability. With the advent of high luminosity collider LHC, need for TDCs with large dynamic range, multi-hit capability and TRIGGERED mode of operation became necessary. A 32 channel TDC was designed for the GRAPES-3 experiment on a CAMAC platform around TDC32, an ASIC developed by micro-electronics group at CERN, Geneva. Four modules were operated in the GRAPES-3 experiment. Here, we present details of the circuit design and their performance over several years. The multi-hit feature of this device was used to study the time structure of particles in the EAS on time scale of ~1 ?s. The distribution of time intervals in the multi-hit data shows an exponential profile with a time constant of ~370 ns. These delayed particles are likely to be neutrons produced in the EAS core that were recorded in the scintillator detectors following the relativistic EAS front. 8. The NANOGrav Nine-year Data Set: Observations, Arrival Time Measurements, and Analysis of 37 Millisecond Pulsars E-print Network Arzoumanian, Z; Burke-Spolaor, S; Chamberlin, S; Chatterjee, S; Christy, B; Cordes, J M; Cornish, N; Crowter, K; Demorest, P B; Dolch, T; Ellis, J A; Ferdman, R D; Fonseca, E; Garver-Daniels, N; Gonzalez, M E; Jenet, F A; Jones, G; Jones, M; Kaspi, V M; Koop, M; Lazio, T J W; Lam, M T; Levin, L; Lommen, A N; Lorimer, D R; Luo, J; Lynch, R S; Madison, D; McLaughlin, M A; McWilliams, S T; Nice, D J; Palliyaguru, N; Pennucci, T T; Ransom, S M; Siemens, X; Stairs, I H; Stinebring, D R; Stovall, K; Swiggum, J K; Vallisneri, M; van Haasteren, R; Wang, Y; Zhu, W 2015-01-01 We present high-precision timing observations spanning up to nine years for 37 millisecond pulsars monitored with the Green Bank and Arecibo radio telescopes as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project. We describe the observational and instrumental setups used to collect the data, and methodology applied for calculating pulse times of arrival; these include novel methods for measuring instrumental offsets and characterizing low signal-to-noise ratio timing results. The time of arrival data are fit to a physical timing model for each source, including terms that characterize time-variable dispersion measure and frequency-dependent pulse shape evolution. In conjunction with the timing model fit, we have performed a Bayesian analysis of a parameterized timing noise model for each source, and detect evidence for time-correlated "red" signals in 10 of the pulsars. Subsequent papers in this series will present further analysis of this data set aimed at detecting o... 9. Ultra-Wideband Time-Difference-of-Arrival High Resolution 3D Proximity Tracking System NASA Technical Reports Server (NTRS) Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Phan, Chau; Dekome, Kent; Dusl, John 2010-01-01 This paper describes a research and development effort for a prototype ultra-wideband (UWB) tracking system that is currently under development at NASA Johnson Space Center (JSC). The system is being studied for use in tracking of lunar./Mars rovers and astronauts during early exploration missions when satellite navigation systems are not available. U IATB impulse radio (UWB-IR) technology is exploited in the design and implementation of the prototype location and tracking system. A three-dimensional (3D) proximity tracking prototype design using commercially available UWB products is proposed to implement the Time-Difference- Of-Arrival (TDOA) tracking methodology in this research effort. The TDOA tracking algorithm is utilized for location estimation in the prototype system, not only to exploit the precise time resolution possible with UWB signals, but also to eliminate the need for synchronization between the transmitter and the receiver. Simulations show that the TDOA algorithm can achieve the fine tracking resolution with low noise TDOA estimates for close-in tracking. Field tests demonstrated that this prototype UWB TDOA High Resolution 3D Proximity Tracking System is feasible for providing positioning-awareness information in a 3D space to a robotic control system. This 3D tracking system is developed for a robotic control system in a facility called "Moonyard" at Honeywell Defense & System in Arizona under a Space Act Agreement. 10. Joint microseismic location and anisotropic tomography using differential arrival times and differential backazimuths NASA Astrophysics Data System (ADS) Li, Junlun; Zhang, Haijiang; Rodi, William L.; Toksoz, M. Nafi 2013-12-01 We develop a new method to locate microseismic events induced by hydraulic fracturing with simultaneous anisotropic tomography, using differential arrival times and differential backazimuths. Compared to the existing double-difference method, our method incorporates backazimuth information to better constrain microseismic locations in the case of downhole linear seismic arrays used for monitoring induced seismicity. The tomography is constrained to a 1-D layered VTI (transversely isotropic structure with a vertical symmetry axis) structure to improve inversion stability given the limited passive seismic data. We derive analytical sensitivities for the elastic moduli (Cij) and layer thickness L, and verify the analytical results with numerical calculations. The forward modelled traveltimes and sensitivities are all calculated analytically without weak anisotropy assumption. By incorporating the relative information among events, the extended double-difference method can provide better relative locations for events and, therefore, can characterize the fractures with higher accuracy. In the two tests with synthetic data, our method provides more accurate relative locations than the traditional methods, which only use absolute information. With fast speed and high accuracy, our inversion scheme is suitable for real-time microseismic monitoring of hydraulic fracturing. 11. Wavepacket approach to particle diffraction by thin targets: Quantum trajectories and arrival times E-print Network C. Efthymiopoulos; N. Delis; G. Contopoulos 2011-11-30 We develop a wavepacket approach to the diffraction of charged particles by a thin material target and we use the de Broglie-Bohm quantum trajectories to study various phenomena in this context. We find the form of the separator, i.e.the limit between the domains of prevalence of the ingoing and outgoing quantum flow. The structure of the quantum-mechanical currents in the neighborhood of the separator implies the formation of an array of \\emph{quantum vortices} (nodal point - X point complexes). We show how the deformation of the separatior near Bragg angles explains the emergence of a diffraction pattern by the de Broglie - Bohm trajectories. We calculate the arrival time distributions for particles scattered at different angles. The predictions of the de Broglie - Bohm theory for\\Delta Tturn to be different from estimates of the same quantity using other theories on time observables like the sum-over-histories or the Kijowski approach. We propose an experimental setup aiming to test such predictions. Finally, we explore the semiclassical limit of short wavelength and short quantum coherence lengths, and demonstrate how, in this case, results with the de Broglie - Bohm trajectories are similar to the classical results of Rutherford scattering. 12. Upper mantle seismic velocity anomaly beneath southern Taiwan as revealed by teleseismic relative arrival times NASA Astrophysics Data System (ADS) Chen, Po-Fei; Huang, Bor-Shouh; Chiao, Ling-Yun 2011-01-01 Probing the lateral heterogeneity of the upper mantle seismic velocity structure beneath southern and central Taiwan is critical to understanding the local tectonics and orogeny. A linear broadband array that transects southern Taiwan, together with carefully selected teleseismic sources with the right azimuth provides useful constraints. They are capable of differentiating the lateral heterogeneity along the profile with systematic coverage of ray paths. We implement a scheme based on the genetic algorithm to simultaneously determine the relative delayed times of the teleseismic first arrivals of array data. The resulting patterns of the delayed times systematically vary as a function of the incident angle. Ray tracing attributes the observed variations to a high velocity anomaly dipping east in the mantle beneath the southeast of Taiwan. Combining the ray tracing analysis and a pseudo-spectral method to solve the 2-D wave propagations, we determine the extent of the anomaly that best fits the observations via the forward grid search. The east-dipping fast anomaly in the upper mantle beneath the southeast of Taiwan agrees with the results from several previous studies and indicates that the nature of the local ongoing arc-continent collision is likely characterized by the thin-skinned style. 13. Evaluation of Operational Procedures for Using a Time-Based Airborne Inter-arrival Spacing Tool NASA Technical Reports Server (NTRS) Oseguera-Lohr, Rosa M.; Lohr, Gary W.; Abbott, Terence S.; Eischeid, Todd M. 2002-01-01 An airborne tool has been developed based on the concept of an aircraft maintaining a time-based spacing interval from the preceding aircraft. The Advanced Terminal Area Approach Spacing (ATAAS) tool uses Automatic Dependent Surveillance-Broadcast (ADS-B) aircraft state data to compute a speed command for the ATAAS-equipped aircraft to obtain a required time interval behind another aircraft. The tool and candidate operational procedures were tested in a high-fidelity, full mission simulator with active airline subject pilots flying an arrival scenario using three different modes for speed control. The objectives of this study were to validate the results of a prior Monte Carlo analysis of the ATAAS algorithm and to evaluate the concept from the standpoint of pilot acceptability and workload. Results showed that the aircraft was able to consistently achieve the target spacing interval within one second (the equivalent of approximately 220 ft at a final approach speed of 130 kt) when the ATAAS speed guidance was autothrottle-coupled, and a slightly greater (4-5 seconds), but consistent interval with the pilot-controlled speed modes. The subject pilots generally rated the workload level with the ATAAS procedure as similar to that with standard procedures, and also rated most aspects of the procedure high in terms of acceptability. Although pilots indicated that the head-down time was higher with ATAAS, the acceptability of head-down time was rated high. Oculometer data indicated slight changes in instrument scan patterns, but no significant change in the amount of time spent looking out the window between the ATAAS procedure versus standard procedures. 14. Fault zone structure determined through the analysis of earthquake arrival times SciTech Connect Michelini, A. 1991-10-01 This thesis develops and applies a technique for the simultaneous determination of P and S wave velocity models and hypocenters from a set of arrival times. The velocity models are parameterized in terms of cubic B-splines basis functions which permit the retrieval of smooth models that can be used directly for generation of synthetic seismograms using the ray method. In addition, this type of smoothing limits the rise of instabilities related to the poor resolving power of the data. V{sub P}/V{sub S} ratios calculated from P and S models display generally instabilities related to the different ray-coverages of compressional and shear waves. However, V{sub P}/V{sub S} ratios are important for correct identification of rock types and this study introduces a new methodology based on adding some coupling (i.e., proportionality) between P and S models which stabilizes the V{sub P}/V{sub S} models around some average preset value determined from the data. Tests of the technique with synthetic data show that this additional coupling regularizes effectively the resulting models. 15. Annual variation in arrival and departure times of carrion insects at carcasses: implications for succession studies in forensic entomology Microsoft Academic Search M. S. Archer 2003-01-01 A succession of insect species associate with decaying bodies, and because of the relatively predictable arrival and departure times of many species, this process is routinely used to estimate minimum post-mortem interval. Corpse fauna are compared with baseline data on succession rates, which are usually taken from decomposing animal carcasses. Baseline data are traditionally collected over a single year only; 16. Possibility of Detecting Moons of Pulsar Planets Through Time-of-Arrival Analysis E-print Network Karen M. Lewis; Penny D. Sackett; Rosemary A. Mardling 2008-05-28 The perturbation caused by planet-moon binarity on the time-of-arrival signal of a pulsar with an orbiting planet is derived for the case in which the orbits of the moon and the planet-moon barycenter are both circular and coplanar. The signal consists of two sinusoids with frequency (2n_p - 3n_b) and (2n_p - n_b ), where n_p and n_b are the mean motions of the planet and moon around their barycenter, and the planet-moon system around the host, respectively. The amplitude of the signal is equal to the fraction sin I[9(M_p M_m)/16(M_p + M_m)^2] [r/R]^5 of the system crossing time R/c, where M_p and M_m are the the masses of the planet and moon, r is their orbital separation, R is the distance between the host pulsar and planet-moon barycenter, I is the inclination of the orbital plane of the planet, and c is the speed of light. The analysis is applied to the case of PSR B1620-26 b, a pulsar planet, to constrain the orbital separation and mass of any possible moons. We find that a stable moon orbiting this pulsar planet could be detected, if the moon had a separation of about one fiftieth of that of the orbit of the planet around the pulsar, and a mass ratio to the planet of ~5% or larger. 17. The Great "Non-Event" of 7 January 2014: Challenges in CME Arrival Time and Geomagnetic Storm Strength Prediction NASA Astrophysics Data System (ADS) Mays, M. L.; Thompson, B. J.; Jian, L.; Evans, R. M.; Savani, N.; Odstrcil, D.; Nieves-Chinchilla, T.; Richardson, I. G. 2014-12-01 We present a case study of the 7 January 2014 event in order to highlight current challenges in space weather forecasting of CME arrival time and geomagnetic storm strength. On 7 January 2014 an X1.2 flare and CME with a radial speed ~2400 km/s was observed from active region 11943. The flaring region was only ten degrees southwest of disk center with extensive dimming south of the active region and preliminary analysis indicated a fairly rapid arrival at Earth (~36 hours). Of the eleven forecasting groups world-wide who participated in CCMC's Space Weather Scoreboard (http://kauai.ccmc.gsfc.nasa.gov/SWScoreBoard), nine predicted early arrivals and six predicted dramatic geomagnetic storm impacts (Kp predictions ranged from 6 to 9). However, the CME only had a glancing blow arrival at Earth - Kp did not rise above 3 and there was no geomagnetic storm. What happened? One idea is that the large coronal hole to the northeast of the active region could have deflected the CME. This coronal hole produced a high speed stream near Earth reaching an uncommon speed of 900 km/s four days after the observed CME arrival. However, no clear CME deflection was observed in the outer coronagraph fields of view (~5-20Rs) where CME measurements are derived to initiate models, therefore deflection seems unlikely. Another idea is the effect of the CME flux rope orientation with respect to Earth orbit. We show that using elliptical major and minor axis widths obtained by GCS fitting for the initial CME parameters in ENLIL would have improved the forecast to better reflect the observed glancing blow in-situ signature. We also explore the WSA-ENLIL+Cone simulations, the background solar wind solution, and compare with the observed CME arrival at Venus (from Venus Express) and Earth. 18. Inter-Arrival Time' Inspired Algorithm and its Application in Clustering and Molecular Phylogeny NASA Astrophysics Data System (ADS) Kolekar, Pandurang S.; Kale, Mohan M.; Kulkarni-Kale, Urmila 2010-10-01 Bioinformatics, being multidisciplinary field, involves applications of various methods from allied areas of Science for data mining using computational approaches. Clustering and molecular phylogeny is one of the key areas in Bioinformatics, which help in study of classification and evolution of organisms. Molecular phylogeny algorithms can be divided into distance based and character based methods. But most of these methods are dependent on pre-alignment of sequences and become computationally intensive with increase in size of data and hence demand alternative efficient approaches. Inter arrival time distribution' (IATD) is a popular concept in the theory of stochastic system modeling but its potential in molecular data analysis has not been fully explored. The present study reports application of IATD in Bioinformatics for clustering and molecular phylogeny. The proposed method provides IATDs of nucleotides in genomic sequences. The distance function based on statistical parameters of IATDs is proposed and distance matrix thus obtained is used for the purpose of clustering and molecular phylogeny. The method is applied on a dataset of 3' non-coding region sequences (NCR) of Dengue virus type 3 (DENV-3), subtype III, reported in 2008. The phylogram thus obtained revealed the geographical distribution of DENV-3 isolates. Sri Lankan DENV-3 isolates were further observed to be clustered in two sub-clades corresponding to pre and post Dengue hemorrhagic fever emergence groups. These results are consistent with those reported earlier, which are obtained using pre-aligned sequence data as an input. These findings encourage applications of the IATD based method in molecular phylogenetic analysis in particular and data mining in general. 19. Arterial spin labelling reveals prolonged arterial arrival time in idiopathic Parkinson's disease PubMed Central Al-Bachari, Sarah; Parkes, Laura M.; Vidyasagar, Rishma; Hanby, Martha F.; Tharaken, Vivek; Leroi, Iracema; Emsley, Hedley C.A. 2014-01-01 Idiopathic Parkinson's disease (IPD) is the second most common neurodegenerative disease, yet effective disease modifying treatments are still lacking. Neurodegeneration involves multiple interacting pathological pathways. The extent to which neurovascular mechanisms are involved is not well defined in IPD. We aimed to determine whether novel magnetic resonance imaging (MRI) techniques, including arterial spin labelling (ASL) quantification of cerebral perfusion, can reveal altered neurovascular status (NVS) in IPD. Fourteen participants with IPD (mean ± SD age 65.1 ± 5.9 years) and 14 age and cardiovascular risk factor matched control participants (mean ± SD age 64.6 ± 4.2 years) underwent a 3T MRI scan protocol. ASL images were collected before, during and after a 6 minute hypercapnic challenge. FLAIR images were used to determine white matter lesion score. Quantitative images of cerebral blood flow (CBF) and arterial arrival time (AAT) were calculated from the ASL data both at rest and during hypercapnia. Cerebrovascular reactivity (CVR) images were calculated, depicting the change in CBF and AAT relative to the change in end-tidal CO2. A significant (p = 0.005) increase in whole brain averaged baseline AAT was observed in IPD participants (mean ± SD age 1532 ± 138 ms) compared to controls (mean ± SD age 1335 ± 165 ms). Voxel-wise analysis revealed this to be widespread across the brain. However, there were no statistically significant differences in white matter lesion score, CBF, or CVR between patients and controls. Regional CBF, but not AAT, in the IPD group was found to correlate positively with Montreal cognitive assessment (MoCA) scores. These findings provide further evidence of alterations in NVS in IPD. PMID:25379411 20. Search for NonRandom Features in Arrival Time Series of Air Showers Observed at Mt.Chacaltaya Microsoft Academic Search N. Ochi; H. Aoki; K. Hashimoto; K. Honda; N. Inoue; N. Kawasumi; N. Ohmori; A. Ohsawa; K. Shinozaki; M. Tamada; I. Tsushima; K. Yokoi; C. Aguirre; N. Martinic; R. Ticona 2003-01-01 Using arrival time series of air showers observed at Mt. Chacaltaya during 1991-1995, we have performed a time series analysis to search for non-random features of UHE cosmic rays. The location of the Chacaltaya air shower array (5200m a.s.l. and in the Southern hemisphere) is expected to reveal new asp ects of UHE cosmic rays which cannot be observed by 1. YO{exclamation_point} - A Time-of-Arrival Receiver for Removal of Femtosecond Helicity-Correlated Beam Effects SciTech Connect Musson, J.; Allison, T.; Freyberger, A. [TJNAF, Newport News, VA 23606 (United States); Kuhn, J.; Quinn, B. [Carnegie-Mellon University, Pittsburgh, PA 15213 (United States) 2004-11-10 The G0 parity violation experiment at Jefferson Lab is based on time-of-flight measurements, and is sensitive to timing effects between the two electron helicity states of the beam. Photon counters triggered by time-of-arrival at the target mandate that timing must be independent of delays associated with different orbits taken by the two helicity states. In addition, the standard 499 MHz beam structure is altered such that 1 of every 16 microbunches are filled, resulting in an arrival frequency of 31.1875 (31) MHz, and an average current of 40 {mu}A. Helicity correction involves identifying and tracking the 31 MHz sub-harmonic, applying a fast/fine phase correction, and finally producing a clean 31 MHz trigger and a 499 MHz clock train. These signals are phase-matched to the beam arrival at the target on the order of femtoseconds. The 10 kHz output bandwidth is sufficiently greater than the 30 Hz helicity flip settling time (500 {mu}s). This permits the system to correct each helicity bin for any orbit-induced timing inequalities. A sampling phase detection scheme is used in order to eliminate the unavoidable 2n/n phase shifts associated with frequency dividers. Conventional receiver architecture and DSP techniques are combined for maximum sensitivity, bandwidth, and flexibility. Results of bench tests, commissioning and production data will be presented. 2. YO!-A Time-of-Arrival Receiver for Removal of Femtosecond Helicity-Correlated Beam Effects SciTech Connect John Musson; Trent Allison; Arne Freyberger; Joachim Kuhn; Brian Quinn 2004-05-02 The G0 parity violation experiment at Jefferson Lab is based on time-of-flight measurements, and is sensitive to timing effects between the two electron helicity states of the beam. Photon counters triggered by time-of-arrival at the target mandate that timing must be independent of delays associated with different orbits taken by the two helicity states. In addition, the standard 499 MHz beam structure is altered such that 1 of every 16 microbunches are filled, resulting in an arrival frequency of 31.1875 (31) MHz, and an average current of 40 {micro}A. Helicity correction involves identifying and tracking the 31 MHz subharmonic, applying a fast/fine phase correction, and finally producing a clean 31 MHz trigger and a 499 MHz clock train. These signals are phase-matched to the beam arrival at the target on the order of femtoseconds. The 10 kHz output bandwidth is sufficiently greater than the 30 Hz helicity flip settling time (500 {micro}s). This permits the system to correct each helicity bin for any orbit-induced timing inequalities. A sampling phase detection scheme is used in order to eliminate the unavoidable 2n/n phase shifts associated with frequency dividers. Conventional receiver architecture and DSP techniques are combined for maximum sensitivity, bandwidth, and flexibility. Results of bench tests, commissioning and production data will be presented. 3. Pulse arrival time is not an adequate surrogate for pulse transit time as a marker of blood pressure. PubMed Zhang, Guanqun; Gao, Mingwu; Xu, Da; Olivier, N Bari; Mukkamala, Ramakrishna 2011-12-01 Pulse transit time (PTT) is a proven, simple to measure, marker of blood pressure (BP) that could potentially permit continuous, noninvasive, and cuff-less BP monitoring (after an initial calibration). However, pulse arrival time (PAT), which is equal to the sum of PTT and the pre-ejection period, is gaining popularity for BP tracking, because it is even simpler to measure. The aim of this study was to evaluate the hypothesis that PAT is an adequate surrogate for PTT as a marker of BP. PAT and PTT were estimated through the aorta using high-fidelity invasive arterial waveforms obtained from six dogs during wide BP changes induced by multiple interventions. These time delays and their reciprocals were evaluated in terms of their ability to predict diastolic, mean, and systolic BP (DBP, MBP, and SBP) per animal. The root mean squared error (RMSE) between the BP parameter predicted via the time delay and the measured BP parameter was specifically used as the evaluation metric. Taking the reciprocals of the time delays tended to reduce the RMSE values. The DBP, MBP, and SBP RMSE values for 1/PAT were 9.8 ± 5.2, 10.4 ± 5.6, and 11.9 ± 6.1 mmHg, whereas the corresponding values for 1/PTT were 5.3 ± 1.2, 4.8 ± 1.0, and 7.5 ± 2.2 mmHg (P < 0.05). Thus tracking BP via PAT was not only markedly worse than via PTT but also unable to meet the FDA BP error limits. In contrast to previous studies, our results quantitatively indicate that PAT is not an adequate surrogate for PTT in terms of detecting challenging BP changes. PMID:21960657 4. P-wave Receiver Functions reveal the Bohemian Massif crust NASA Astrophysics Data System (ADS) Kampfova Exnerova, Hana; Plomerova, Jaroslava; Vecsey, Ludek 2015-04-01 In this study we present initial results of P-wave Receiver Functions (RF) calculated from broad-band waveforms of teleseismic events recorded by temporary and permanent stations in the Bohemian Massif (BM, Central Europe). Temporary arrays BOHEMA I (2001-2003), BOHEMA II (2004-2005) and BOHEMA III (2005-2006) operated during passive seismic experiments oriented towards studying velocity structure of the lithosphere and the upper mantle. Receiver Functions show relative response of the Earth structure under a seismic station and nowadays represent frequently-used method to retrieve structure of the crust, whose knowledge is needed in various studies of the upper mantle. The recorded waveforms are composites of direct P and P-to-S converted waves that reverberate in the structure beneath the receiver (Ammon, 1997). The RFs are sensitive to seismic velocity contrast and are thus suited to identifying velocity discontinuities in the crust, including the Mohorovi?i? discontinuity (Moho). Relative travel-time delays of the converted phases detected in the RFs are transformed into estimates of discontinuity depths assuming external information on the vp/vs and P velocity. To evaluate RFs we use the Multiple-taper spectral correlation (MTC) method (Park and Levin, 2000) and process signals from teleseismic events at epicentral distances of 30 - 100° with magnitude Mw > 5.5. Recordings are filtered with Butterworth band-pass filter of 2 - 8 s. To select automatically signals which are strong enough, we calculate signal-to-noise ratios (SNR) in two steps. In the first step we calculate SNR for signals from intervals (-1s, 3s)/(-10s, -2s), where P-arrival time represent time zero. In the second step we broaden the intervals and calculate SNR for (-1s, 9s)/(-60s, -2s). We also employ forward modelling of the RFs using Interactive Receiver Functions Forward Modeller (IRFFM) (Tkal?i? et al., 2010) to produce, in the first step, one-dimensional velocity models under individual seismic station. Stacked traces of the RFs show strong conversions with positive polarity (indicating a velocity increase across the discontinuity) between 3.3 and 4.5 s after the P-wave arrival at almost all stations. We relate these pulses to conversions at the Moho discontinuity. Assuming a constant crustal vp/vs ratio (1.73) and average crustal velocity vp=6.3 km/s for all stations, analogically to Geissler et al (2012), we multiply the evaluated Ps delay times by factor of 8.3 km/s and estimate the Moho beneath the Bohemian Massif at depths between 27 and 37 km. The crust is thinnest in the western part of the BM, beneath the SW end of the Eger Rift. The Moldanubian part of the BM exhibits the thickest crust. At most of the stations we also see one or two intra-crustal conversions, sometimes stronger than that related to the Moho. Several stations exhibit significant variations of the RF with back-azimuth. The aim of this study is to update existing three dimensional P-velocity crustal model of the Bohemian Massif (Karousová et al., 2012) compiled from control-source seismic results. 5. Fast computation algorithm of ray-paths and their travel times including later arrivals for a multi layered earth model Microsoft Academic Search R. Kubota; E. Nishiyama; K. Murase; J. Kasahara 2005-01-01 Seismic tomography techniques have been rapidly developed to interpret crustal seismic refraction data. Forward modeling approaches, however, are also necessary to examine an initial model for inversion and\\/or later phases. Ray-paths and travel times of later phases, as well as fastest arrivals, such as reflection, later refraction and P-SV converted waves, provide indispensable information for seismic crustal structure analyses. Although 6. Predicting the Arrival Time of Coronal Mass Ejections with the Graduated Cylindrical Shell and Drag Force Model NASA Astrophysics Data System (ADS) Shi, Tong; Wang, Yikang; Wan, Linfeng; Cheng, Xin; Ding, Mingde; Zhang, Jie 2015-06-01 Accurately predicting the arrival of coronal mass ejections (CMEs) to the Earth based on remote images is of critical significance for the study of space weather. In this paper, we make a statistical study of 21 Earth-directed CMEs, specifically exploring the relationship between CME initial speeds and transit times. The initial speed of a CME is obtained by fitting the CME with the Graduated Cylindrical Shell model and is thus free of projection effects. We then use the drag force model to fit results of the transit time versus the initial speed. By adopting different drag regimes, i.e., the viscous, aerodynamics, and hybrid regimes, we get similar results, with a least mean estimation error of the hybrid model of 12.9 hr. CMEs with a propagation angle (the angle between the propagation direction and the Sun–Earth line) larger than their half-angular widths arrive at the Earth with an angular deviation caused by factors other than the radial solar wind drag. The drag force model cannot be reliably applied to such events. If we exclude these events in the sample, the prediction accuracy can be improved, i.e., the estimation error reduces to 6.8 hr. This work suggests that it is viable to predict the arrival time of CMEs to the Earth based on the initial parameters with fairly good accuracy. Thus, it provides a method of forecasting space weather 1–5 days following the occurrence of CMEs. 7. Dual subduction tectonics and plate dynamics of central Japan shown by three-dimensional P-wave anisotropic structure NASA Astrophysics Data System (ADS) Ishise, Motoko; Miyake, Hiroe; Koketsu, Kazuki 2015-07-01 The central Japanese subduction zone is characterized by a complex tectonic setting affected by the dual subduction of oceanic plates and collisions between the island arcs. To better understand of the subduction system, we performed an anisotropic tomography analysis using P-wave arrival times from local earthquakes to determine the three-dimensional structure of P-wave azimuthal anisotropy in the overriding plate and the Pacific and Philippine Sea (PHS) slabs. The principal characteristics of anisotropy in the subducted and subducting plates are (1) in the overriding plate, the distribution pattern of fast direction of crustal anisotropy coincides with that of the strike of geological structure, (2) in the two oceanic plates, fast propagation directions of P-wave were sub-parallel to the directions of seafloor spreading. Additionally, our tomographic images demonstrate that (1) the bottom of the Median Tectonic Line, the longest fault zone in Japan, reaches to the lower crust, and seems to link to the source region of an inter-plate earthquake along the PHS slab, (2) the segmentation of the PHS slab - the Izu Islands arc, the Nishi-Shichito ridge, and the Shikoku basin - due to the formation history, is reflected in the regional variation of anisotropy. The tomographic study further implies that there might be a fragment of the Pacific slab suggested by a previous study beneath the Tokyo metropolitan area. The overall findings strongly indicate that seismic anisotropy analysis provide potentially useful information to understand a subduction zone. 8. Search for Coincidences in Time and Arrival Direction of Auger Data with Astrophysical Transients SciTech Connect Anchordoqui, Luis; Collaboration, for the Pierre Auger 2007-06-01 The data collected by the Pierre Auger Observatory are analyzed to search for coincidences between the arrival directions of high-energy cosmic rays and the positions in the sky of astrophysical transients. Special attention is directed towards gamma ray observations recorded by NASA's Swift mission, which have an angular resolution similar to that of the Auger surface detectors. In particular, we check our data for evidence of a signal associated with the giant flare that came from the soft gamma repeater 1806-20 on December 27, 2004. 9. P-Wave Wave in a Slinky NSDL National Science Digital Library John Lahr This animation shows how P-waves (primary, or compressional, waves) travel through a Slinky toy. It is accompanied by a brief written explanation that describes some of the properties of P-waves and how they are generated in a real Slinky. 10. 3D P-Wave Velocity Structure of the Crust and Relocation of Earthquakes in 21 the Lushan Source Area NASA Astrophysics Data System (ADS) Yu, X.; Wang, X.; Zhang, W. 2014-12-01 The double difference seismic tomography method is applied to the absolute first arrival P wave arrival times and high quality relative P arrival times of the Lushan seismic sequence to determine the detailed crustal 3D P wave velocity structure and the hypocenter parameters in the Lushan seismic area. The results show that the Lushan mainshock locates at 30.28 N, 103.98 E, with the depth of 16.38 km. The leading edge of aftershock in the northeast of mainshock present a spade with a steep dip angle, the aftershocks' extended length is about 12 km. In the southwest of the Lushan mainshock, the leading edge of aftershock in low velocity zone slope gently, the aftershocks' extended length is about 23 km. The P wave velocity structure of the Lushan seismic area shows obviously lateral heterogeneity. The P wave velocity anomalies represent close relationship with topographic relief and geological structure. In Baoxing area the complex rocks correspond obvious high-velocity anomalies extending down to 15 km depth?while the Cenozoic rocks are correlated with low-velocity anomalies. Our high-resolution tomographic model not only displays the general features contained in the previous models, but also reveals some new features. An obvious high-velocity anomaly is visible in Daxing area. The high-velocity anomalies beneath Baoxing and Daxing connect each other in 10 km depth, which makes the contrast between high and low velocity anomalies more sharp. Above 20 km depth the velocity structure in southwest and northeast segment of the mainshock shows a big difference: low-velocity anomalies are dominated the southwest segment, while high-velocity anomalies rule the northeast segment. The Lushan mainshock locates at the leading edge of a low-velocity anomaly surrounded by the Baoxing and Daxing high-velocity anomalies. The Lushan aftershocks in southwest are distributed in low-velocity anomalies or the transition belt: the footwall represents low-velocity anomalies, while the hanging wall shows high-velocity anomalies. The northeastern aftershocks are distributed at the boundary between high-velocity anomalies in Baoxing and Daxing area. The main seismogenic layer dips to northwest. 11. Automatic re-picking and re-weighting of first arrival times from the Italian Seismic Network waveforms database Microsoft Academic Search R. di Stefano; A. Amato; F. Aldersons; E. Kissling 2002-01-01 The high resolution P-wave tomography of the Italian Peninsula and surrounding regions from crustal to upper mantle depths is the aim of a joint project between INGV (Roma) and ETH (Zurich). The project is subdivided into two steps, first of which is to establish a 3D P-wave velocity model for the crust, using both passive and active seismic sources. Getting 12. Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles DOEpatents Benjamin, R.F. 1987-03-10 An apparatus is disclosed for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously. 3 figs. 13. Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles DOEpatents Benjamin, Robert F. (315 Rover Blvd., Los Alamos, NM 87544) 1987-01-01 An apparatus for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously. 14. Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles DOEpatents Benjamin, R.F. 1983-10-18 An apparatus for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously. 15. Connecting speeds, directions and arrival times of 22 coronal mass ejections from the sun to 1 AU SciTech Connect Möstl, C.; Veronig, A. M.; Rollett, T.; Temmer, M.; Peinhart, V. [Kanzelhöhe Observatory-IGAM, Institute of Physics, University of Graz (Austria); Amla, K.; Hall, J. R.; Liewer, P. C.; De Jong, E. M. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States); Colaninno, R. C. [Space Sciences Division, Naval Research Laboratory, Washington, DC (United States); Davies, J. A.; Harrison, R. A. [RAL Space, Harwell Oxford, Didcot (United Kingdom); Lugaz, N.; Farrugia, C. J.; Galvin, A. B. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH (United States); Liu, Y. D. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Luhmann, J. G. [Space Science Laboratory, University of California, Berkeley, CA (United States); Vršnak, B., E-mail: [email protected] [Hvar Observatory, Faculty of Geodesy, University of Zagreb, Ka?i?eva 26, HR-10000, Zagreb (Croatia) 2014-06-01 Forecasting the in situ properties of coronal mass ejections (CMEs) from remote images is expected to strongly enhance predictions of space weather and is of general interest for studying the interaction of CMEs with planetary environments. We study the feasibility of using a single heliospheric imager (HI) instrument, imaging the solar wind density from the Sun to 1 AU, for connecting remote images to in situ observations of CMEs. We compare the predictions of speed and arrival time for 22 CMEs (in 2008-2012) to the corresponding interplanetary coronal mass ejection (ICME) parameters at in situ observatories (STEREO PLASTIC/IMPACT, Wind SWE/MFI). The list consists of front- and backsided, slow and fast CMEs (up to 2700 km s{sup –1}). We track the CMEs to 34.9 ± 7.1 deg elongation from the Sun with J maps constructed using the SATPLOT tool, resulting in prediction lead times of –26.4 ± 15.3 hr. The geometrical models we use assume different CME front shapes (fixed-?, harmonic mean, self-similar expansion) and constant CME speed and direction. We find no significant superiority in the predictive capability of any of the three methods. The absolute difference between predicted and observed ICME arrival times is 8.1 ± 6.3 hr (rms value of 10.9 hr). Speeds are consistent to within 284 ± 288 km s{sup –1}. Empirical corrections to the predictions enhance their performance for the arrival times to 6.1 ± 5.0 hr (rms value of 7.9 hr), and for the speeds to 53 ± 50 km s{sup –1}. These results are important for Solar Orbiter and a space weather mission positioned away from the Sun-Earth line. 16. Alignment of leading-edge and peak-picking time of arrival methods to obtain accurate source locations SciTech Connect Roussel-Dupre, R.; Symbalisty, E.; Fox, C.; and Vanderlinde, O. 2009-08-01 The location of a radiating source can be determined by time-tagging the arrival of the radiated signal at a network of spatially distributed sensors. The accuracy of this approach depends strongly on the particular time-tagging algorithm employed at each of the sensors. If different techniques are used across the network, then the time tags must be referenced to a common fiducial for maximum location accuracy. In this report we derive the time corrections needed to temporally align leading-edge, time-tagging techniques with peak-picking algorithms. We focus on broadband radio frequency (RF) sources, an ionospheric propagation channel, and narrowband receivers, but the final results can be generalized to apply to any source, propagation environment, and sensor. Our analytic results are checked against numerical simulations for a number of representative cases and agree with the specific leading-edge algorithm studied independently by Kim and Eng (1995) and Pongratz (2005 and 2007). 17. Position surveillance using one active ranging satellite and time-of-arrival of a signal from an independent satellite NASA Technical Reports Server (NTRS) Anderson, R. E.; Frey, R. L.; Lewis, J. R. 1980-01-01 Position surveillance using one active ranging/communication satellite and the time-of-arrival of signals from an independent satellite was shown to be feasible and practical. A towboat on the Mississippi River was equipped with a tone-code ranging transponder and a receiver tuned to the timing signals of the GOES satellite. A similar transponder was located at the office of the towing company. Tone-code ranging interrogations were transmitted from the General Electric Earth Station Laboratory through ATS-6 to the towboat and to the ground truth transponder office. Their automatic responses included digital transmissions of time-of-arrival measurements derived from the GOES signals. The Earth Station Laboratory determined ranges from the satellites to the towboat and computed position fixes. The ATS-6 lines-of-position were more precise than 0.1 NMi, 1 sigma, and the GOES lines-of-position were more precise than 1.6 NMi, 1 sigma. High quality voice communications were accomplished with the transponders using a nondirectional antenna on the towboat. The simple and effective surveillance technique merits further evaluation using operational maritime satellites. 18. On the possibility to discriminate the mass of the primary cosmic ray using the muon arrival times from extensive air showers: Application for Pierre Auger Observatory SciTech Connect Arsene, N.; Rebel, H.; Sima, O. [Institute of Space Science (ISS), Bucharest-Magurele, P.O. Box MG-23 (Romania) and Physics Department, University of Bucharest, Bucharest-Magurele (Romania); Karlsruhe Institute of Technology, Karlsruhe (Germany); Physics Department, University of Bucharest, Bucharest-Magurele (Romania) 2012-11-20 In this paper we study the possibility to discriminate the mass of the primary cosmic ray by observing the muon arrival times in ground detectors. We analyzed extensive air showers (EAS) induced by proton and iron nuclei with the same energy 8 Multiplication-Sign 10{sup 17} eV simulated with CORSIKA, and analyzed the muon arrival times at ground measured by the infill array detectors of the Pierre Auger Observatory (PAO). From the arrival times of the core and of the muons the atmospheric depth of muon generation locus is evaluated. The results suggest a potential mass discrimination on the basis of muon arrival times and of the reconstructed atmospheric depth of muon production. An analysis of a larger set of CORSIKA simulations carried out for primary energies above 10{sup 18} eV is in progress. 19. Predicting the Arrival Time of Coronal Mass Ejections with the Graduated Cylindrical Shell and Drag Force Model E-print Network Shi, Tong; Wan, Linfeng; Cheng, Xin; Ding, Mingde; Zhang, Jie 2015-01-01 Accurately predicting the arrival of coronal mass ejections (CMEs) at the Earth based on remote images is of critical significance in the study of space weather. In this paper, we make a statistical study of 21 Earth directed CMEs, exploring in particular the relationship between CME initial speeds and transit times. The initial speed of a CME is obtained by fitting the CME with the Graduated Cylindrical Shell model and is thus free of projection effects. We then use the drag force model to fit results of the transit time versus the initial speed. By adopting different drag regimes, i.e., the viscous, aerodynamics, and hybrid regimes, we get similar results, with the least mean estimation error of the hybrid model of 12.9 hours. CMEs with a propagation angle (the angle between the propagation direction and the Sun-Earth line) larger than its half angular width arrive at the Earth with an angular deviation caused by factors other than the radial solar wind drag. The drag force model cannot be well applied to s... 20. A one-particle time of arrival operator for a free relativistic spin- 0 charged particle in (1 + 1) dimensions NASA Astrophysics Data System (ADS) Bunao, Joseph; Galapon, Eric A. 2015-02-01 We construct a one-particle TOA operator T ˆ canonically conjugate with the Hamiltonian describing a free, charged, spin- 0, relativistic particle in one spatial dimension and show that it is maximally symmetric. We solve for its eigenfunctions and show that they form a complete and non-orthogonal set. Plotting the time evolution of their corresponding probability densities, it implies that the eigenfunctions become more localized at the origin at the time equal to their eigenvalues. That is, a particle being described by an eigenfunction of T ˆ is in a state of definite arrival time at the origin and at the corresponding eigenvalue. We also calculate the TOA probability distribution of a particle in some initial state. 1. ESTIMATING THE ARRIVAL TIME OF EARTH-DIRECTED CORONAL MASS EJECTIONS AT IN SITU SPACECRAFT USING COR AND HI OBSERVATIONS FROM STEREO SciTech Connect Mishra, Wageesh; Srivastava, Nandita, E-mail: [email protected] [Udaipur Solar Observatory, Physical Research Laboratory, P.O. Box 198, Badi Road, Udaipur 313 001 (India) 2013-07-20 Predicting the arrival time and transit speed of coronal mass ejections (CMEs) near the Earth is critical to understanding the solar-terrestrial relationship. Even though STEREO observations now provide multiple views of CMEs in the heliosphere, the true speeds derived from stereoscopic reconstruction of SECCHI coronagraph data are not quite sufficient for accurate forecasting of the arrival time at Earth of a majority of CMEs. This uncertainty is due to many factors that change CME kinematics, such as the interaction of two or more CMEs or the interaction of CMEs with the pervading solar wind. In order to understand the propagation of CMEs, we have used the three-dimensional triangulation method on SECCHI coronagraph (COR2) images and geometric triangulation on the J-maps constructed from Heliospheric Imagers HI1 and HI2 data for eight Earth-directed CMEs observed during 2008-2010. Based on the reconstruction, and implementing the drag-based model for the distance where the CMEs could not be tracked unambiguously in the interplanetary (IP) medium, the arrival time of these CMEs have been estimated. These arrival times have also been compared with the actual arrival times as observed by in situ instruments. The analysis reveals the importance of heliospheric imaging for improved forecasting of the arrival time and direction of propagation of CMEs in the IP medium. 2. Ratios in Higher Order Statistics (RHOS) values of Seismograms for Improved Automatic P-Phase Arrival Detection Microsoft Academic Search Mulugeta Dugda; Abebe Kebede 2010-01-01 In this paper we present two new procedures for automatic detection and picking of P-wave arrivals. The first involves the application of kurtosis and skewness on the vector magnitude of three component seismograms. Customarily, P-wave arrival detection techniques use vertical component seismogram which is appropriate only for teleseismic events. The inherent weakness of those methods stems from the fact that 3. [Development of estimated time of arrival method and usefulness in pulmonary artery/vein separation 3D-CT]. PubMed Nakamori, Katsutoshi; Nagasawa, Naoki; Yamazaki, Akio; Kubooka, Naoya; Yamao, Yoshikazu; Murashima, Syuichi; Fujita, Makiko; Takao, Motoshi; Tenpaku, Hironori; Shimamoto, Akira; Maki, Hiroaki; Sakuma, Hajime 2014-11-01 We have developed an estimated time of arrival (ETA) method as a new single-phase scan for pulmonary artery/vein separation. This method enables differentiation of CT values between arteries and veins by means of two-step consecutive injection of contrast medium based on the pulmonary circulation time. This paper presents an overview of the ETA method and scan technique. Since the ETA method is a single-phase scan, it uses a low radiation dose compared with the conventional multi-phase scan. Moreover, this method eliminates gaps due to breath holding. The ETA method can detect irregularities and obtain high-quality pulmonary artery/vein separation 3D-CT images. PMID:25410332 4. Lightning First Pulses Used in the "Last" (Time-of-Arrival) and "Atlas" (Single Station) Total Lightning Mapping Systems NASA Technical Reports Server (NTRS) Markson, Ralph; Ruhnke, Lothar 1999-01-01 The first RF pulse from "total lightning' discharges (cloud and ground flashes) has been used in different ways to locate the origin of flashes in two new types of lightning detection systems. The multisensor LASI time-of-arrival (TOA) system uses GPS timing of the first pulse. The ATLAS single sensor system uses the amplitude of the first pulse, which is invariant in magnitude and polarization for all lightning discharges, to determine distance from the sensor. It is significantly more accurate than past single sensor lightning mapping systems. The polarity of the first pulse generally identifies lightning type (IC or CG). Both systems utilize only the first pulse which makes signal processing much simpler than with previous lightning locating systems. Knowing the position where lightning begins (maximum electric fields, mixed phase hydrometeors and updrafts) is valuable for identifying convective cells producing the hazardous meteorological conditions caused by thunderstorms. It is also important for research studying thunderstorm electrification and associated microphysical problems. 5. Delay Analysis in Temperature-Constrained Hard Real-Time Systems with General Task Arrivals Microsoft Academic Search Shengquan Wang; Riccardo Bettati 2006-01-01 In this paper, we study temperature-constrained hard real- time systems, where real-time guarantees must be met with- out exceeding safe temperature levels within the proces- sor. Dynamic speed scaling is one of the major techniques to manage power so as to maintain safe temperature lev- els. As example, we adopt a simple reactive speed con- trol technique in our work. 6. Tensor field guidance for time-based waypoint arrival of UAVs by 4D trajectory generation Microsoft Academic Search Shane C. Degen; Luis Mejias; Jason J. Ford; Rodney A. Walker 2009-01-01 This paper looks at incorporating time information into a waypoint trajectory-generation technique known as Vector Field Guidance to give a 4D trajectory generator henceforth known as Tensor Field Guidance. The time-based information is local in that it is relative from waypoint to waypoint. We envisage that a higher-level controller or an Air Traffic Management system automates the waypoint generation, while 7. Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1987 Annual Report. SciTech Connect Buettner, Edwin W.; Nelson, V. Lance 1990-01-01 This project monitored the daily passage of smolts during the 1988 spring outmigration at two migrant traps; one each on the Snake and Clearwater rivers. Due to the low runoff year, chinook salmon catch at the Snake River trap was very low. Steelhead trout catch was higher than normal, probably due to trap modifications and because the trap was moved to the east side of the river. Chinook salmon and steelhead trout catch at the Clearwater River trap was similar to 1987. Total cumulative recovery of PIT tagged fish at the three dams, with PIT tag detection systems was: 55% for chinook salmon, 73% for hatchery steelhead trout, and 75% for wild steelhead trout. Travel time through Lower Granite Reservoir for PIT tagged chinook salmon and steelhead trout, marked at the head of the reservoir, was affected by discharge. Statistical analysis showed that as discharge increased from 40 kcfs to 80 kcfs, chinook salmon travel time decreased three fold, and steelhead trout travel time decreased two fold. There was a statistical difference between estimates of travel time through Lower Granite Reservoir for PIT tagged and freeze branded steelhead trout, but not for chinook salmon. These differences may be related to the estimation techniques used for PIT tagged and freeze branded groups, rather than real differences in travel time. 10 figs, 15 tabs. 8. Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1988 Annual Report. SciTech Connect Buettner, Edwin W.; Nelson, William R. 1989-10-01 This project monitored the daily passage of smelts during the 1988 spring outmigration at two migrant traps; one each on the Snake and Clear-water rivers. Due to the low runoff year, chinook salmon catch at the Snake River trap was very low. Steelhead trout catch was higher than normal, probably due to trap modifications and because the trap was moved to the east side of the river. Chinook salmon and steelhead trout catch at the Clearwater River trap was similar to 1987. Total cumulative recovery of PIT tagged fish at the three dams, with PIT tag detection systems was: 55% for chinook salmon, 73% for hatchery steelhead trout, and 75% for wild steelhead trout. Travel time through Lower Granite Reservoir for PIT tagged chinook salmon and steelhead trout, marked at the head of the reservoir, was affected by discharge. Statistical analysis showed that as discharge increased from 40 kcfs to 80 kcfs, chinook salmon travel time decreased three fold, and steelhead trout travel time decreased two fold. There was a statistical difference between estimates of travel time through Lower Granite Reservoir for PIT tagged and freeze branded steelhead trout, but not for chinook salmon. These differences may be related to the estimation techniques used for PIT tagged and freeze branded groups, rather than real differences in travel time. 9. Deriving the orbital properties of pulsators in binary systems through their light arrival time delays NASA Astrophysics Data System (ADS) Murphy, Simon J.; Shibahashi, Hiromoto 2015-07-01 We present the latest developments to the phase modulation method for finding binaries among pulsating stars. We demonstrate how the orbital elements of a pulsating binary star can be obtained analytically, that is, without converting time delays to radial velocities by numerical differentiation. Using the time delays directly offers greater precision, and allows the parameters of much smaller orbits to be derived. The method is applied to KIC 9651065, KIC 10990452 and KIC 8264492, and a set of the orbital parameters is obtained for each system. Radial velocity curves for these stars are deduced from the orbital elements thus obtained. 10. Florian Lhl FLASH seminar February 26, 2008 Commissioning of the bunch arrival time E-print Network , a new beam pick-up (design: K. Hacker) was installed instead of the ring electrodes to improve the pick-up performance. 17mm 14.5mm 1.2mm thick Alumina disk old ring electrode: new design: 6.2mm #12;Florian Löhl FLASH) The timing information of the electron bunch is transferred into a laser amplitude modulation 11. for four time intervals: Late Pleistocene (before humans arrived in the Americas), Holocene (when E-print Network by the National Center for Eco- logical Analysis and Synthesis (funded by NSF grant DEB-0072909, the University of California, and the University of California, Santa Barbara). Additional support was also provided and com- ments on the manuscript. R E V I E W Noisy Clockwork: Time Series Analysis of Population 12. Effect of method and timing of castration on newly arrived stocker cattle Technology Transfer Automated Retrieval System (TEKTRAN) An experiment was conducted to determine the effects of castration method and timing on the performance and health of newly received stocker cattle. Two hundred and seventy-one crossbred male calves (184 bulls, 87 steers; 210 ± 14.7 kg) were purchased at auction barns and shipped in three groups. ... 13. Supercurrent in p-wave Holographic Superconductor E-print Network Hua-Bi Zeng; Wei-Min Sun; Hong-Shi Zong 2011-02-01 The p-wave andp+ip$-wave holographic superconductors with fixed DC supercurrent are studied by introducing a non-vanishing vector potential. We find that close to the critical temperature$T_c$of zero current, the numerical results of both the p wave model and the$p+ip$model are the same as those of Ginzburg-Landau (G-L) theory, for example, the critical current$j_c \\sim (T_c-T)^{3/2}$and the phase transition in the presence of a DC current is a first order transition. Besides the similar results between both models, the$p+ip$superconductor shows isotropic behavior for the supercurrent, while the p-wave superconductor shows anisotropic behavior for the supercurrent. 14. Post-Arrival Screening for Malaria in Asymptomatic Refugees Using Real-Time PCR PubMed Central Matisz, Chelsea E.; Naidu, Prenilla; Shokoples, Sandra E.; Grice, Diane; Krinke, Valerie; Brown, Stuart Z.; Kowalewska-Grochowska, Kinga; Houston, Stan; Yanow, Stephanie K. 2011-01-01 Malaria is a significant health risk to refugee populations originating from endemic areas, but there is little consensus on screening and/or treatment approaches for malaria in this population. Furthermore, detection of malaria in semi-immune asymptomatic refugees is limited by the sensitivity of diagnostic tests used for screening. We determined the prevalence of malaria by microscopy and real-time polymerase chain reaction (PCR) in a consecutive population of 324 asymptomatic refugees examined in Edmonton, Canada, during 2009–2010. Although all thick and thin blood smear results were negative, 10 subjects (3.1%) tested PCR positive for Plasmodium DNA. Interestingly, 6 of 10 PCR positive subjects are at risk of malaria relapse by P. vivax or P. ovale infections. These results suggest that appropriate guidelines for malaria screening should consider the risk of relapsing infections, and they highlight the potential usefulness of real-time PCR in the diagnosis of asymptomatic malaria. PMID:21212221 15. Random number generation based on the time of arrival of single photons. PubMed Ma, Hai-Qiang; Xie, Yuejian; Wu, Ling-An 2005-12-20 We report the demonstration of a new type of true random number generator based on the random distribution of the time interval between photons from a single-photon-like source. The experimental setup is simple and robust against mechanical and temperature disturbances. With improved detector resolution and efficiency, the random number bit rate could be increased by more than an order of magnitude to satisfy practical requirements. PMID:16381524 16. Random number generation based on the time of arrival of single photons NASA Astrophysics Data System (ADS) Ma, Hai-Qiang; Xie, Yuejian; Wu, Ling-An 2005-12-01 We report the demonstration of a new type of true random number generator based on the random distribution of the time interval between photons from a single-photon-like source. The experimental setup is simple and robust against mechanical and temperature disturbances. With improved detector resolution and efficiency, the random number bit rate could be increased by more than an order of magnitude to satisfy practical requirements. 17. Teleseismic P-wave tomogram of the Yellowstone plume Microsoft Academic Search Huaiyu Yuan; Ken Dueker 2005-01-01 Inversion of a new data set of teleseismic P-wave travel-times from three PASSCAL seismic deployments around the Yellowstone hotspot reveals a 100 km diameter upper mantle plume that extends from the Yellowstone volcanic caldera to 500 km depth and dips 20° to the northwest. A monotonic decrease in the velocity perturbation of the plume from ?3.2% at 100 km to 18. Teleseismic P-wave tomogram of the Yellowstone plume Microsoft Academic Search Huaiyu Yuan; Ken Dueker 2005-01-01 Inversion of a new data set of teleseismic P-wave travel-times from three PASSCAL seismic deployments around the Yellowstone hotspot reveals a 100 km diameter upper mantle plume that extends from the Yellowstone volcanic caldera to 500 km depth and dips 20° to the northwest. A monotonic decrease in the velocity perturbation of the plume from -3.2% at 100 km to 19. Orbital magnetic dynamics in chiral p -wave superconductors NASA Astrophysics Data System (ADS) Braude, V.; Sonin, E. B. 2006-08-01 We present a theory of orbital magnetic dynamics for a chiral p -wave superconductor with broken time-reversal symmetry. In contrast to the common Landau-Lifshitz theory for spin ferromagnets, the case of orbital magnetism cannot be described in terms of local magnetization density. Hence, it is impossible to define unambiguously the spontaneous magnetic moment: the latter would depend on conditions of its experimental investigation. As an example of this we consider orbital magnetization waves and the domain-structure energy. 20. Decay constants of$P$-wave mesons E-print Network Guo-Li Wang 2007-05-18 Decay constants of$P$-wave mesons are computed in the framework of instantaneous Bethe-Salpeter method (Salpeter method). By analyzing the parity and possible charge conjugation parity, we give the relativistic configurations of wave functions with definite parity and possible charge conjugation parity. With these wave functions as input, the full Salpeter equations for different$P$-wave states are solved, and the mass spectra as well as the numerical values of wave functions are obtained. Finally we compute the leptonic decay constants of heavy-heavy and heavy-light$^3P_0$,$^3P_1$and$^1P_1states. 1. One dimensional P wave velocity structure of the crust beneath west Java and accurate hypocentre locations from local earthquake inversion SciTech Connect Supardiyono; Santosa, Bagus Jaya [Physics Department, Faculty of Mathematics and Natural Sciences, State University of Surabaya, Surabaya (Indonesia) and Physics Department, Faculty of Mathematics and Natural Sciences, Sepuluh Nopember Institute of Technology, Surabaya (Indonesia); Physics Department, Faculty of Mathematics and Natural Sciences, Sepuluh Nopember Institute of Technology, Surabaya (Indonesia) 2012-06-20 A one-dimensional (1-D) velocity model and station corrections for the West Java zone were computed by inverting P-wave arrival times recorded on a local seismic network of 14 stations. A total of 61 local events with a minimum of 6 P-phases, rms 0.56 s and a maximum gap of 299 Degree-Sign were selected. Comparison with previous earthquake locations shows an improvement for the relocated earthquakes. Tests were carried out to verify the robustness of inversion results in order to corroborate the conclusions drawn out from our reasearch. The obtained minimum 1-D velocity model can be used to improve routine earthquake locations and represents a further step toward more detailed seismotectonic studies in this area of West Java. 2. Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1986 Annual Report. SciTech Connect Buettner, Edwin W.; Nelson, V. Lance 1987-09-01 This project monitored the daily passage of smolts during the 1986 spring outmigration at two migrant traps, one each on the Snake and Clearwater rivers. Average migration rates for freeze-branded chinook salmon smolts were 28.2 km per day and 22.1 km per day for steelhead trout smolts between release sites and the head of Lower Granite Reservoir. The yearling chinook salmon migration begins in earnest when Salmon River discharge makes a significant rise in early to mid-April. Most yearling chinook salmon pass into Lower Granite Reservoir in April followed by passage of steelhead trout in May. Chinook salmon smolt recapture data from the Snake River trap suggest a strong dependence of migration rate on quantity of Snake and Salmon River discharge, although no statistical correlation exists at this time. Daily and seasonal descaling rates were calculated for each species at each trap. Rates were highest for hatchery steelhead trout, intermediate for yearling chinook salmon, and lowest for wild steelhead trout. Descaling rates were generally higher in 1986 than those observed in 1984 and 1985. 4 refs., 9 figs., 15 tabs. 3. Joint inversion of gravity and arrival time data from Parkfield: New constraints on structure and hypocenter locations near the SAFOD drill site USGS Publications Warehouse Roecker, S.; Thurber, C.; McPhee, D. 2004-01-01 Taking advantage of large datasets of both gravity and elastic wave arrival time observations available for the Parkfield, California region, we generated an image consistent with both types of data. Among a variety of strategies, the best result was obtained from a simultaneous inversion with a stability requirement that encouraged the perturbed model to remain close to a starting model consisting of a best fit to the arrival time data. The preferred model looks essentially the same as the best-fit arrival time model in areas where ray coverage is dense, with differences being greatest at shallow depths and near the edges of the model where ray paths are few. Earthquake locations change by no more than about 100 m, the general effect being migration of the seismic zone to the northeast, closer to the surface trace of the San Andreas Fault. Copyright 2004 by the American Geophysical Union. 4. Seismic Imaging of a Bimaterial Interface along the Hayward Fault, CA, with Fault Zone Head Waves and Direct P Arrivals NASA Astrophysics Data System (ADS) Allam, A. A.; Ben-Zion, Y.; Peng, Z. 2012-12-01 We show the existence and image properties of a seismic velocity contrast along the Hayward fault using moveout analysis and joint inversion of fault zone head waves (FZHW) and direct P arrivals. The analysis is based on FZHW and P arrival times for 5834 earthquakes recorded at up to 27 stations of the Berkeley Digital Seismic Network (BDSN) and the Northern California Seismic Network (NCSN). Robust identification of FZHW requires the combination of multiple techniques due to the diverse instrumentation of the BDSN and NCSN. For single-component short-period instruments, FZHW are identified by examining sets of waveforms from both sides of the fault, and finding on one (the slow) side emergent reversed-polarity arrivals before the direct P waves. For three-component broadband and strong-motion instruments, the FZHW are identified with polarization analysis that detects early arrivals from the fault direction before the regular body waves with polarizations in the source-receiver directions. The initial results indicate a velocity contrast of 5-12% along the central portion of the Hayward fault, with the southwest side having faster P wave velocity in agreement with tomography results. A systematic moveout between the FZHW and direct P waves for a roughly 70 km long fault section suggest a single continuous fault interface over that distance. We also find some complexities near the junction with the Calaveras fault in the southernmost portion and near the city of Oakland. Regions giving rise to variable FZHW arrival times can be correlated to first order with the presence of lithological complexity, including slivers of high-velocity metamorphic rocks and serpentinized rocks. The seismic velocity contrast and geological complexity have important implications for earthquake and rupture dynamics of the Hayward fault. 5. ARRIVAL TIME CALCULATION FOR INTERPLANETARY CORONAL MASS EJECTIONS WITH CIRCULAR FRONTS AND APPLICATION TO STEREO OBSERVATIONS OF THE 2009 FEBRUARY 13 ERUPTION SciTech Connect Moestl, C.; Rollett, T.; Temmer, M.; Veronig, A. M.; Biernat, H. K. [Institute of Physics, University of Graz, Graz A-8010 (Austria); Lugaz, N. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Farrugia, C. J.; Galvin, A. B. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States); Davies, J. A.; Harrison, R. A.; Crothers, S. [RAL Space, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Luhmann, J. G. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Zhang, T. L.; Baumjohann, W., E-mail: [email protected] [Space Research Institute, Austrian Academy of Sciences, Graz A-8042 (Austria) 2011-11-01 One of the goals of the NASA Solar TErestrial RElations Observatory (STEREO) mission is to study the feasibility of forecasting the direction, arrival time, and internal structure of solar coronal mass ejections (CMEs) from a vantage point outside the Sun-Earth line. Through a case study, we discuss the arrival time calculation of interplanetary CMEs (ICMEs) in the ecliptic plane using data from STEREO/SECCHI at large elongations from the Sun in combination with different geometric assumptions about the ICME front shape [fixed-{Phi} (FP): a point and harmonic mean (HM): a circle]. These forecasting techniques use single-spacecraft imaging data and are based on the assumption of constant velocity and direction. We show that for the slow (350 km s{sup -1}) ICME on 2009 February 13-18, observed at quadrature by the two STEREO spacecraft, the results for the arrival time given by the HM approximation are more accurate by 12 hr than those for FP in comparison to in situ observations of solar wind plasma and magnetic field parameters by STEREO/IMPACT/PLASTIC, and by 6 hr for the arrival time at Venus Express (MAG). We propose that the improvement is directly related to the ICME front shape being more accurately described by HM for an ICME with a low inclination of its symmetry axis to the ecliptic. In this case, the ICME has to be tracked to >30{sup 0} elongation to obtain arrival time errors < {+-} 5 hr. A newly derived formula for calculating arrival times with the HM method is also useful for a triangulation technique assuming the same geometry. 6. Observations of high-frequency P wave earthquake and explosion spectra compared with ?-3, ?-2, and sharpe source models NASA Astrophysics Data System (ADS) Walter, William R.; Brune, James N.; Priestley, Keith F.; Fletcher, Jon 1988-06-01 Observations of 10-, 20-, and 30-Hz P wave spectral amplitudes from earthquakes and explosions are compared with the Archambeau [1968, 1972] earthquake model featuring a P wave falloff of ?-3 beyond the corner frequency, a modified Brune [1970, 1971] earthquake model with ?-2 falloff, and the Sharpe [1942] explosion model which has a ?-2 falloff. The Archambeau and Sharpe models have been, in part, the basis of a proposal by Evernden et al. [1986] that high-frequency (?30 Hz) seismic energy could provide an effective solution to the problem of detection and identification of low-yield coupled and fully decoupled underground nuclear explosions. The observations of earthquakes show an increase in spectral amplitude with moment approximately in agreement with the ?-2 falloff model and, for larger moments, in disagreement with the ?-3 model. Comparison of theoretical and actual seismograms narrow-band filtered at 30 Hz shows that in part the increase in spectral amplitude of earthquakes is due to the complex and long duration of the rupture process and not because of an increase in an impulsive first arrival like that characteristic of an explosion. The 30-Hz amplitudes for explosions show much scatter, and many events have a spectral falloff greater than the ?-2 predicted by the Sharpe model. Whether this is due entirely to attenuation or is the actual source spectrum is not determined. High stress drop earthquakes are predicted to have larger spectral amplitudes than the Sharpe model. Thus any discrimination technique using high-frequency P wave spectra should probably take into account differences in pulse shape and amplitude in the time domain. 7. Gamma-Ray Burst Arrival Time Localizations: Simultaneous Observations by Pioneer Venus Orbiter, Compton Gamma-Ray Observatory, and ULYSSES NASA Astrophysics Data System (ADS) Laros, J. G.; Hurley, K. C.; Fenimore, E. E.; Klebesadel, R. W.; Briggs, M. S.; Kouveliotou, C.; McCollough, M. L.; Fishman, G. J.; Meegan, C. A.; Cline, T. L.; Boer, M.; Niel, M. 1998-10-01 Between the Compton Gamma Ray Observatory (CGRO) launch in 1991 April and the Pioneer Venus Orbiter (PVO) demise in 1992 October, concurrent coverage by CGRO, PVO, and Ulysses was obtained for several hundred gamma-ray bursts (GRBs). Although most of these were below the PVO and Ulysses thresholds, 37 were positively detected by all three spacecraft, with data quality adequate for quantitative localization analysis. All were localized independently to ~2° accuracy by the CGRO Burst and Transient Source Experiment (BATSE), and three were also localized by COMPTEL. We computed arrival-time error boxes, whose larger dimensions range from about 2' to several degrees and whose smaller dimensions are in the arcminute range. Twelve have areas less than 10 arcmin2, and only four have areas greater than 1 deg2. The area of the smallest box is 0.44 arcmin2. We find that the overall BATSE localization accuracy for these events is consistent with the most recent stated uncertainties. This work indicates that the ROSAT soft X-ray source found within a preliminary IPN error box for GB920501 (Trig 1576) (Hurley et al.) is less likely to be the GRB counterpart than previously reported. 8. The estimation of subsample time delay of arrival in the discrete-time measurement of phase delay Microsoft Academic Search Douglas L. Maskell; Graham S. Woods 1999-01-01 Time delay estimation (TDE) techniques based upon the identification of the extremum of the cross-correlation function, or some other statistic of two signals, typically use some form of interpolation between points to obtain a resolution finer than the sample period. Often these techniques introduce some bias because of mismatch between the interpolating function and the actual discrete-time correlation function. We 9. The effects of iron deficiency anemia on p wave duration and dispersion PubMed Central Simsek, Hakk?; Gunes, Yilmaz; Demir, Cengiz; Sahin, Musa; Gumrukcuoglu, Hasan Ali; Tuncer, Mustafa 2010-01-01 OBJECTIVES: The association between P wave dispersion and iron deficiency anemia has not been documented in the literature. In this study, we evaluated P wave dispersion in patients with iron deficiency anemia and the possible relationships between P wave dispersion and other echocardiographic parameters. INTRODUCTION: The iron status of an individual may play an important role in cardiovascular health. Anemia is an independent risk factor for adverse cardiovascular outcomes. P wave dispersion is a simple electrocardiographic marker that has a predictive value for the development of atrial fibrillation. Apart from cardiovascular diseases, several conditions, such as seasonal variation, alcohol intake and caffeine ingestion, have been demonstrated to affect P wave dispersion. METHODS: The study included 97 patients who had iron deficiency anemia and 50 healthy subjects. The cases were evaluated with a clinical examination and diagnostic tests that included 12?lead electrocardiography and transthoracic echocardiography. RESULTS: Compared to the control group, patients with iron deficiency anemia showed significantly longer maximum P wave duration (Pmax) (91.1±18.0 vs. 85.8±6.7 msec, p?=?0.054), P wave dispersion (PWD) (48.1±7.7 vs. 40.9±5.6 msec, p<0.001), mitral inflow deceleration time (DT) (197.5±27.9 vs. 178.8±8.9 msec, p<0.001) and isovolumetric relaxation time (IVRT) (93.3±9.2 vs. 77.4±8.2 msec, p<0.001); they also showed increased heart rate (85.7±16.1 vs. 69.0±4.4, p<0.001) and frequency of diastolic dysfunction (7 (7.2%) vs. 0). Correlation analysis revealed that PWD was significantly correlated with IVRT, DT, heart rate, the presence of anemia and hemoglobin level. CONCLUSIONS: Iron deficiency anemia may be associated with prolonged P wave duration and dispersion and impaired diastolic left ventricular filling. PMID:21243273 10. The effects of pre-ejection period on post-exercise systolic blood pressure estimation using the pulse arrival time technique Microsoft Academic Search Mico Yee Man Wong; Emma Pickwell-MacPherson; Yuan Ting Zhang; Jack C. Y. Cheng 2011-01-01 Pulse arrival time (PAT) is comprised of the vascular transit time (TT) through the arterial system and the pre-ejection period\\u000a (PEP) in the heart. It has been used to predict arterial blood pressure (BP) without using a cuff. The aim of this study was\\u000a to investigate the effects of including the PEP on the accuracy of cuffless systolic BP (SBP) 11. P-Wave Electron-Hydrogen Scattering NASA Technical Reports Server (NTRS) Bhtia, Anand 2012-01-01 A variational wave function incorporating short range correlations via Hylleraas type functions plus long-range polarization terms of the polarized orbital type but with smooth cut-off factors has been used to calculate P-wave phase shifts for electron-hydrogen scattering. This approach gives the direct r(exp -4) potential and a non-local optical potential which is definite. The resulting phase shifts have rigorous lower bounds and the convergence is much faster than those obtained without the modification of the target function. Final results will be presented at the conference. 12. Tracer arrival timing-insensitive technique for estimating flow in MR perfusion-weighted imaging using singular value decomposition with a block-circulant deconvolution matrix. PubMed Wu, Ona; Østergaard, Leif; Weisskoff, Robert M; Benner, Thomas; Rosen, Bruce R; Sorensen, A Gregory 2003-07-01 Relative cerebral blood flow (CBF) and tissue mean transit time (MTT) estimates from bolus-tracking MR perfusion-weighted imaging (PWI) have been shown to be sensitive to delay and dispersion when using singular value decomposition (SVD) with a single measured arterial input function. This study proposes a technique that is made time-shift insensitive by the use of a block-circulant matrix for deconvolution with (oSVD) and without (cSVD) minimization of oscillation of the derived residue function. The performances of these methods are compared with standard SVD (sSVD) in both numerical simulations and in clinically acquired data. An additional index of disturbed hemodynamics (oDelay) is proposed that represents the tracer arrival time difference between the AIF and tissue signal. Results show that PWI estimates from sSVD are weighted by tracer arrival time differences, while those from oSVD and cSVD are not. oSVD also provides estimates that are less sensitive to blood volume compared to cSVD. Using PWI data that can be routinely collected clinically, oSVD shows promise in providing tracer arrival timing-insensitive flow estimates and hence a more specific indicator of ischemic injury. Shift maps can continue to provide a sensitive reflection of disturbed hemodynamics. PMID:12815691 13. Computer program modifications of Open-file report 82-1065; a comprehensive system for interpreting seismic-refraction and arrival-time data using interactive computer methods USGS Publications Warehouse Ackermann, Hans D.; Pankratz, Leroy W.; Dansereau, Danny A. 1983-01-01 The computer programs published in Open-File Report 82-1065, A comprehensive system for interpreting seismic-refraction arrival-time data using interactive computer methods (Ackermann, Pankratz, and Dansereau, 1982), have been modified to run on a mini-computer. The new version uses approximately 1/10 of the memory of the initial version, is more efficient and gives the same results. 14. Eastern Edge of the Laurentian Cratonic Lithosphere Beneath Southern Quebec from Teleseismic P Waves NASA Astrophysics Data System (ADS) Menke, W. H.; Neitz, T.; Levin, V. L.; Darbyshire, F. A.; Bastow, I. D. 2014-12-01 The eastern margin of Laurentia was deformed by the late-Proterozoic Grenville orogeny, which metamorphosed the original Archean-age cratonic crust and added extensive intrusive rocks. The Laurentian crust clearly extends as far east as the Laurentian Highlands, just north of the St. Laurence River, where Grenville-deformed rocks outcrop. Small outliers of Grenville-deformed rocks amongst west-thrust Paleozoic sediments, 20-50 km east of the Appalachian Front in southern Quebec, suggest that the Laurentian crust extends beneath the shallow thrust sheets of this region, too. On the other hand, Laurentia does not extend east of the Norumbega fault in coastal Maine, for the crust there is derived from the Avalon micro-continent. We search for the eastern edge of Laurentia within this ~250 km wide interval using relative arrival times of teleseismic P waves which ascend sub-vertically through the lithosphere beneath the region. These times are expected to be most sensitive to upper mantle compressional velocity and so to be able to discriminate the cratonic lithosphere on the basis of its faster than average speed. We use signal-correlation techniques to measured delay times for all broadband seismic stations in the region, including the QMIII array, which is especially designed to have high station density near the Appalachian Front. As expected, we observe central Quebec to have anomalously early times and coastal Maine to have anomalously late times, by as much as ±1s, when compared to the predictions of the global AK135 traveltime model. The boundary between the two arrival time regimes is sharp and is collinear with the Appalachian Front, to within the ± 25 km spatial resolution of our study. We hypothesize that it represents the eastern edge of the Laurentian cratonic lithosphere. Tomographic inversion of the data indicates a 0.2 km/s (2.4%) drop in compressional velocity of the shallow (90 km deep) mantle from west to east across the boundary. This is a strong jump in mantle properties, as either a 400 deg C increase in temperature or a 11 decrease in Mg# (or some other as yet unidentified source of heterogeneity) is needed to explain it. Future work will use teleseismic shear waves to further characterize the lithosphere across this boundary. 15. Effect of immiscible liquid contaminants on P-wave transmission through natural aquifer samples SciTech Connect Geller, Jil T.; Ajo-Franklin, Jonathan B.; Majer, Ernest L. 2003-01-31 We performed core-scale laboratory experiments to examine the effect of non-aqueous phase liquid (NAPL) contaminants on P-wave velocity and attenuation in heterogeneous media. This work is part of a larger project to develop crosswell seismic methods for minimally invasive NAPL detection. The test site is the former DOE Pinellas Plant in Florida, which has known NAPL contamination in the surficial aquifer. Field measurements revealed a zone of anomalously high seismic attenuation, which may be due to lithology and/or contaminants (NAPL or gas phase). Intact core was obtained from the field site, and P-wave transmission was measured by the pulse-transmission technique with a 500 kHz transducer. Two types of samples were tested: a clean fine sand from the upper portion of the surficial aquifer, and clayey-silty sand with shell fragments and phosphate nodules from the lower portion. Either NAPL trichloroethene or toluene was injected into the initially water-saturated sample. Maximum NAPL saturations ranged from 30 to 50% of the pore space. P-wave velocity varied by approximately 4% among the water-saturated samples, while velocities decreased by 5 to 9% in samples at maximum NAPL saturation compared to water-saturated conditions. The clay and silt fraction as well as the larger scatterers in the clayey-silty sands apparently caused greater P-wave attenuation compared to the clean sand. The presence of NAPLs caused a 34 to 54% decrease in amplitudes of the first arrival. The central frequency of the transmitted energy ranged from 85 to 200 kHz, and was sensitive to both grain texture and presence of NAPL. The results are consistent with previous trends observed in homogeneous sand packs. More data will be acquired to interpret P-wave tomograms from crosswell field measurements, determine the cause of high attenuation observed in the field data and evaluate the sensitivity of seismic methods for NAPL detection. 16. P wave velocity structure in the Yucca Mountain, Nevada, region Microsoft Academic Search Leiph Preston; Ken Smith; David von Seggern 2007-01-01 We have performed a crustal tomographic inversion using over 250,000 P arrival times from local earthquake sources and surface explosions in the Yucca Mountain, Nevada, region. Within the shallowest 2–3 km, topographic features tend to dominate the structure with high velocities imaged under Bare Mountain, the Funeral Mountains, and higher terrain to the east of Yucca Mountain and low velocities 17. Chiral p-wave order in Sr2RuO4 NASA Astrophysics Data System (ADS) Kallin, Catherine 2012-04-01 Shortly after the discovery in 1994 of superconductivity in Sr2RuO4, it was proposed on theoretical grounds that the superconducting state may have chiral p-wave symmetry analogous to the A phase of superfluid 3He. Substantial experimental evidence has since accumulated in favor of this pairing symmetry, including several interesting recent results related to broken time-reversal symmetry (BTRS) and vortices with half of the usual superconducting flux quantum. Great interest surrounds the possibility of chiral p-wave order in Sr2RuO4, since this state may exhibit topological order analogous to that of a quantum Hall state, and can support such exotic physics as Majorana fermions and non-Abelian winding statistics, which have been proposed as one route to a quantum computer. However, serious discrepancies remain in trying to connect the experimental results to theoretical predictions for chiral p-wave order. In this paper, I review a broad range of experiments on Sr2RuO4 that are sensitive to p-wave pairing, triplet superconductivity and time-reversal symmetry breaking and compare these experiments to each other and to theoretical predictions. In this context, the evidence for triplet pairing is strong, although some puzzles remain. The ‘smoking gun’ experimental results for chiral p-wave order, those which directly look for evidence of BTRS in the superconducting state of Sr2RuO4, are most perplexing when the results are compared with each other and to theoretical predictions. Consequently, the case for chiral p-wave superconductivity in Sr2RuO4 remains unresolved, suggesting the need to consider either significant modifications to the standard chiral p-wave models or possible alternative pairing symmetries. Recent ideas along these lines are discussed. 18. The relationship between CME speed and soft X-ray emission and the prediction of the arrival times of ICMEs near Earth NASA Astrophysics Data System (ADS) Klein, Karl-Ludwig; Salas Matamoros, Carolina 2015-04-01 While STEREO observations provided a major step forward in our understanding of the interplanetary propagation of coronal mass ejections (CME), the basic observational input to the forecasting of CME arrival at Earth has for a long time been the CME speed estimated from coronagraphic measurements on the Sun-Earth line. In this contribution the performance of these measurements is compared with a proxy approach: the speed of Earth-directed CMEs in the corona is inferred from the fluence of the associated soft X-ray bursts, using an empirical relationship that we established considering CMEs originating near the solar limb in solar cycle 23. We use both the CME speed measured in the plane of the sky by SoHO/LASCO and the speed estimated from the soft X-rays as an input to the simple empirical interplanetary propagation model devised by Gopalswamy and coworkers, and compared the predicted arrival times of the interplanetary CMEs (ICMEs) near 1 AU with in situ measurements in the case of 26 well-observed events. We show that for a range of CME speeds between about 700 and 1700 km/s the soft X-ray proxy gives a better prediction of the ICME arrival than the use of the plane-of-the-sky speed measured by the coronagraph on the Sun-Earth line. 19. Crosswell seismic studies in gas hydrate-bearing sediments: P wave velocity and attenuation tomography NASA Astrophysics Data System (ADS) Bauer, K.; Haberland, Ch.; Pratt, R. G.; Ryberg, T.; Weber, M. H.; Mallik Working Group 2003-04-01 We present crosswell seismic data from the Mallik 2002 Production Research Well Program, an international research project on Gas Hydrates in the Northwest Territories of Canada. The program participants include 8 partners; The Geological Survey of Canada (GSC), The Japan National Oil Corporation (JNOC), GeoForschungsZentrum Potsdam (GFZ), United States Geological Survey (USGS), United States Department of the Energy (USDOE), India Ministry of Petroleum and Natural Gas (MOPNG)/Gas Authority of India (GAIL) and the Chevron-BP-Burlington joint venture group. The crosswell seismic measurements were carried out by making use of two 1160 m deep observation wells (Mallik 3L-38 and 4L-38) both 45 m from and co-planar with the 1188 m deep production research well (5L-38). A high power piezo-ceramic source was used to generate sweeped signals with frequencies between 100 and 2000 Hz recorded with arrays of 8 hydrophones per depth level. A depth range between 800 and 1150 m was covered, with shot and receiver spacings of 0.75 m. High quality data could be collected during the survey which allow for application of a wide range of crosswell seismic methods. The initial data analysis included suppression of tube wave energy and picking of first arrivals. A damped least-squares algorithm was used to derive P-wave velocities from the travel time data. Next, t* values were derived from the decay of the amplitude spectra, which served as input parameters for a damped least-squares attenuation tomography. The initial results of the P-wave velocity and attenuation tomography reveal significant features reflecting the stratigraphic environment and allow for detection and eventually quantification of gas hydrate bearing sediments. A prominent correlation between P velocity and attenuation was found for the gas hydrate layers. This contradicts to the apparently more meaningful inverse correlation as it was determined for the gas hydrates at the Blake Ridge but supports the results from the Mallik 2L-38 sonic log data. The P velocities and attenuation values, if combined with other information can be important for the quantitative evaluation of the gas hydrate saturation, and may further constrain petrophysical models of the hydrate bearing sediment formation. 20. Computed bipolar precordial leads for improved P wave detection. PubMed Batchvarov, Velislav N; Behr, Elijah R 2015-01-01 We present an excerpt from a 24-hour 12-lead Holter recording acquired in an 85-year-old man investigated for the Brugada syndrome. The rhythm cannot be determined because no P waves can be discerned due to the high level of noise and to merging of the T and P waves. The P waves, however, are clearly visible and the noise is considerably reduced in bipolar precordial leads computed from the standard unipolar precordial leads. The case demonstrates the potential usefulness of various computed leads for rhythm analysis by detecting P waves that are not visible in the standard leads. PMID:25537311 1. Stereoscopic study of the kinematic evolution of a coronal mass ejection and its driven shock from the sun to the earth and the prediction of their arrival times SciTech Connect Hess, Phillip; Zhang, Jie, E-mail: [email protected] [School of Physics, Astronomy and Computational Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States) 2014-09-01 We present a detailed study of the complete evolution of a coronal mass ejection (CME). We have tracked the evolution of both the ejecta and its shock, and further fit the evolution of the fronts to a simple but physics-based analytical model. This study focuses on the CME initiated on the Sun on 2012 July 12 and arriving at the Earth on 2012 July 14. Shock and ejecta fronts were observed by white light images, as well as in situ by the Advanced Composition Explorer satellite. We find that the propagation of the two fronts is not completely dependent upon one another, but can each be modeled in the heliosphere with a drag model that assumes the dominant force of affecting CME evolution to be the aerodynamic drag force of the ambient solar wind. Results indicate that the CME ejecta front undergoes a more rapid deceleration than the shock front within 50 R {sub ?} and therefore the propagation of the two fronts is not completely coupled in the heliosphere. Using the graduated cylindrical shell model, as well as data from time-elongation stack plots and in situ signatures, we show that the drag model can accurately describe the behavior of each front, but is more effective with the ejecta. We also show that without the in situ data, based on measurements out to 80 R {sub ?} combined with the general values for drag model parameters, the arrival of both the shock and ejecta can be predicted within four hours of arrival. 2. Influence of health-related quality of life on time from symptom onset to hospital arrival and the risk of readmission in patients with myocardial infarction PubMed Central Henriksson, Catrin; Larsson, Margareta; Herlitz, Johan; Karlsson, Jan-Erik; Wernroth, Lisa; Lindahl, Bertil 2014-01-01 Background Despite increased awareness of the importance of early treatment in acute myocardial infarction (AMI), the delay from symptom onset to hospital arrival is still too long and rehospitalisations are frequent. Little is known about how health-related quality of life (HRQL) affects delay time and the frequency of readmissions. Method We used quality registers to investigate whether patients’ HRQL has any impact on delay time with a new AMI, and on the rate of readmissions during the first year. Patients with AMI <75?years, with HRQL assessed with EQ-5D at 1-year follow-up, and who thereafter had a new AMI registered, were evaluated for the correlation between HRQL and delay time (n=454). The association between HRQL and readmissions was evaluated among those who had an additional AMI and a new 1-year follow-up registration (n=216). Results Patients who reported poor total health status (EQ-VAS ?50), compared to those who reported EQ-VAS 81–100, had tripled risk to delay ?2?h from symptom onset to hospital arrival (adjusted OR 3.01, 95% CI 1.43 to 6.34). Patients scoring EQ-VAS ?50 had also a higher risk of readmissions in the univariate analysis (OR 3.08, 95% CI 1.71 to 5.53). However, the correlation did not remain significant after adjustment (OR 1.99, 95% CI 0.90 to 4.38). EQ-index was not independently associated with delay time or readmissions. Conclusions Aspects of total health status post-AMI were independently associated with delay time to hospital arrival in case of a new AMI. However, the influence of total health status on the risk of readmissions was less clear. PMID:25525504 3. Environmental and lunar cues are predictive of the timing of river entry and spawning-site arrival in lake sturgeon Acipenser fulvescens. PubMed Forsythe, P S; Scribner, K T; Crossman, J A; Ragavendran, A; Baker, E A; Davis, C; Smith, K K 2012-07-01 The associations were quantified between daily and interannual variation in the timing of a closed population of lake sturgeon Acipenser fulvescens migration and arrival at spawning sites with stream environmental and lunar covariates. Spawning data were gathered from 1262 fish in Black Lake, Michigan 2001 to 2008 and by video monitoring 2000 to 2002. Sex-specific variation in responses to external cues was also tested. Results showed that a greater number of individuals initiated migration from lake to riverine habitats at dawn and dusk relative to other times of the day. Current and lagged effects of water temperature and river discharge, and periods in the lunar cycle were important variables in models quantifying movements into the river and timing of adult arrival at spawning sites. Different suites of covariates were predictive of A. fulverscens responses during different periods of the spawning season. The timing of initiation of migration and spawning, and the importance of covariates to the timing of these events, did not differ between sexes. Stream flow and temperature covaried with other variables including day length and the lunar cycle. Anthropogenic disruption of relationships among variables may mean that environmental cues may no longer reliably convey information for Acipenseriformes and other migratory fishes. PMID:22747803 4. Arrival time and magnitude of airborne fission products from the Fukushima, Japan, reactor incident as measured in Seattle, WA, USA E-print Network J. Diaz Leon; D. A. Jaffe; J. Kaspar; A. Knecht; M. L. Miller; R. G. H. Robertson; A. G. Schubert 2011-08-23 We report results of air monitoring started due to the recent natural catastrophe on 11 March 2011 in Japan and the severe ensuing damage to the Fukushima Dai-ichi nuclear reactor complex. On 17-18 March 2011, we registered the first arrival of the airborne fission products 131-I, 132-I, 132-Te, 134-Cs, and 137-Cs in Seattle, WA, USA, by identifying their characteristic gamma rays using a germanium detector. We measured the evolution of the activities over a period of 23 days at the end of which the activities had mostly fallen below our detection limit. The highest detected activity amounted to 4.4 +/- 1.3 mBq/m^3 of 131-I on 19-20 March. 5. Trends of some high quantiles of average and extremes inter-arrival times and rainfall depths at daily scale for an Italian Sub-Alpine area NASA Astrophysics Data System (ADS) Ferraris, Stefano; Agnese, Carmelo; Baiamonte, Giorgio; Canone, Davide; Previati, Maurizio; Cat Berro, Daniele; Mercalli, Luca 2015-04-01 Modeling of rainfall statistical structure represents an important research area in hydrology, meteorology, atmospheric physics and climatology, because of the several theoretical and practical implications. The statistical inference of the alternation of wet periods (WP) and dry periods (DP) in daily rainfall records can be achieved through the modelling of inter-arrival time-series (IT), defined as the succession of times elapsed from a rainy day and the one immediately preceding it. It has been shown previously that the statistical structure of IT can be well described by the 3-parameter Lerch distribution (Lch). In this work, Lch was successfully applied to IT data belonging to a sub-alpine area (Piemonte and Valle d'Aosta, NW Italy); furthermore the same statistical procedure was applied to daily rainfall records to ITs associated. The analysis has been carried out for 26 daily rainfall long-series (? 90 yr of observations). The main objective of this work was to detect temporal trends of some features describing the statistical structure of both inter-arrival time-series (IT) and associated rainfall depth (H). Each time-series was divided on subsets of five years long and for each of them the estimation of the Lch parameter was performed, so to extend the trend analysis to some high quantiles. 6. Comparison of P-wave and S-wave data in a fractured reservoir E-print Network Al-Mustafa, Husam Mustafa 1993-01-01 and eliminate the efect of multiples. Velocity analyses were performed to determine the stacking velocities. The data were NMO corrected, muted, and stacked. Residual static corrections were applied to correct for misalignments of reflectors caused by near...-surface irregularities. Due to the presence of noise at frequencies less than 10 Hz in the P-wave data, a highpass filter was applied to the P-wave data before calculating the residual static corrections a second time. Frequencies less than 10 Hz were rejected... 7. Upper crustal structure of Newberry Volcano from P-wave tomography and finite difference waveform modeling E-print Network Hooft, Emilie modeling Matthew W. Beachly,1 Emilie E. E. Hooft,1 Douglas R. Toomey,1 and Gregory P. Waite2 Received 16 body in the upper crust at Newberry Volcano. We obtain a P-wave tomographic image by combining travel-time tomography alone. Citation: Beachly, M. W., E. E. E. Hooft, D. R. Toomey, and G. P. Waite (2012), Upper 8. Evidence for the subducting lithosphere under Southern Vancouver Island and Western Oregon from teleseismic P wave conversions SciTech Connect Langston, C.A. 1981-05-10 Long-period teleseismic P waves recorded at VIC (Victoria, British Columbia) and COR (Corvallis, Orgeon) show anomalously large Ps conversions and later arriving P-to-S reverberations not observed from typical continental crustal sections or from previously proposed structures for these stations determined from refraction surveys. The timing and large amplitude of the Ps phase, relative to direct P, suggests a high velocity-contrast interface at 45 to 50 km depth under VIC and COR forming the base of a distinct low velocity zone. This interface is proposed to be the oceanic Moho which is being subducted under North America. Off azimuth Ps recorded at COR is consistent with a 20/sup 0/ eastward dip for the interface. Horizontal particle motion at both sites show evidence for lateral heterogeneity in local crustal structure. The distinct low velocity zone and its negative gradient with depth has important consequences for refraction interpretation in the region since the usual assumption of increasing velocity with depth is violated. Crustal thicknesses derived from such misinterpretation may be overestimated. In principle, this type of structure suggests a solution for the Vancouver Island crustal thickness problem in which the observed positive Bouguer gravity anomaly is inconsistent with the 50 km thick crustal thickness derived from previous refraction work. 9. Analysis of near-source contributions to early P-wave coda for underground explosions. II. Frequency dependence SciTech Connect Lay, T. 1987-08-01 Analysis of dispersion in more than 1600 teleseismic short-period P waves from 46 underground explosions has established that near-source effects are responsible for systematic frequency-dependent variations observed in the first 15 sec of the P signals. Explosions from the Nevada, Amchitka, and Novaya Zemlya test sites exhibit a common magnitude dependence of the dispersive behavior, with smaller events having relatively enriched low-frequency (0.4 to 0.8 Hz) energy in the coda. For the Nevada and Amchitka sites, the larger events have relatively enhanced high-frequency (0.8 to 1.1 hz) energy in the coda as well, which may be a consequence of diminished high-frequency content of the direct arrivals. The dispersive behavior also correlates well with known source depths for the Nevada Test Site and Amchitka events, and with estimated pP delay times for the Novaya Zemlya events, indicating that burial depth and/or explosion size are important factors. Pahute Mesa tests show a secondary dependence on position in the site, with centrally located events having stronger dispersion, as well as more pronounced slowly varying azimuthal patterns in frequency dependence. Stations at azimuths NNE from the Mesa have particularly strong dispersion for centrally located events. Spatial and azimuthal variations for Pahute Mesa events do not appear to be the result of aftershock radiation but instead are associated with frequency-dependent defocusing and scattering from a high-velocity structure beneath the test site. 10. A Study of Process Arrival Patterns for MPI Collective Operations E-print Network Yuan, Xin A Study of Process Arrival Patterns for MPI Collective Operations Ahmad Faraj Pitch Patarasuk Xin Process arrival pattern, which denotes the timing when different processes arrive at an MPI collective the process arrival patterns in a set of MPI programs on two common cluster platforms, use a micro 11. Repeatable timing of northward departure, arrival and breeding in Black-tailed Godwits Limosa l. limosa , but no domino effects Microsoft Academic Search Pedro M. Lourenço; Rosemarie Kentie; Julia Schroeder; Niko M. Groen; Jos C. E. W. Hooijmeijer; Theunis Piersma When early breeding is advantageous, migrants underway to the breeding areas may be time stressed. The timing of sequential\\u000a events such as migration and breeding is expected to be correlated because of a “domino effect”, and would be of particular\\u000a biological importance if timings are repeatable within individuals between years. We studied a colour-marked population of\\u000a Black-tailed Godwits Limosa l. 12. Determination of three-dimensional velocity anomalies under a seismic array using first P arrival times from local earthquakes 1. A homogeneous initial model Microsoft Academic Search Keiiti Aki; W. H. K. Lee 1976-01-01 Geiger's method of locating local earthquakes has been extended to include the effect of P velocity variation along the ray paths in three dimensions. The crustal structure was modeled by rectangular blocks, and a parameter was assigned to each block describing the perturbation of P wave slowness in the block. On the basis of an initial model, a set of 13. Collisional properties of p-wave Feshbach molecules. PubMed Inada, Yasuhisa; Horikoshi, Munekazu; Nakajima, Shuta; Kuwata-Gonokami, Makoto; Ueda, Masahito; Mukaiyama, Takashi 2008-09-01 We have observed p-wave Feshbach molecules for all three combinations of the two lowest hyperfine spin states of 6Li. By creating a pure molecular sample in an optical trap, we measured the inelastic collision rates of p-wave molecules. We have also measured the elastic collision rate from the thermalization rate of a breathing mode which was excited spontaneously upon molecular formation. PMID:18851195 14. Embedded Fiber Optic Sensors for Measuring Transient Detonation/Shock Behavior;Time-of-Arrival Detection and Waveform Determination. SciTech Connect Chavez, Marcus Alexander; Willis, Michael David; Covert, Timothy T. 2014-09-01 The miniaturization of explosive components has driven the need for a corresponding miniaturization of the current diagnostic techniques available to measure the explosive phenomena. Laser interferometry and the use of spectrally coated optical windows have proven to be an essential interrogation technique to acquire particle velocity time history data in one- dimensional gas gun and relatively large-scale explosive experiments. A new diagnostic technique described herein allows for experimental measurement of apparent particle velocity time histories in microscale explosive configurations and can be applied to shocks/non-shocks in inert materials. The diagnostic, Embedded Fiber Optic Sensors (EFOS), has been tested in challenging microscopic experimental configurations that give confidence in the technique's ability to measure the apparent particle velocity time histories of an explosive with pressure outputs in the tenths of kilobars to several kilobars. Embedded Fiber Optic Sensors also allow for several measurements to be acquired in a single experiment because they are microscopic, thus reducing the number of experiments necessary. The future of EFOS technology will focus on further miniaturization, material selection appropriate for the operating pressure regime, and extensive hydrocode and optical analysis to transform apparent particle velocity time histories into true particle velocity time histories as well as the more meaningful pressure time histories. 15. Discretized versus continuous models of p-wave interacting fermions in one dimension SciTech Connect Muth, Dominik; Fleischhauer, Michael; Schmidt, Bernd [Fachbereich Physik und Forschungszentrum OPTIMAS, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany); Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet Frankfurt, D-60438 Frankfurt am Main (Germany) 2010-07-15 We present a general mapping between continuous and lattice models of Bose and Fermi gases in one dimension, interacting via local two-body interactions. For s-wave interacting bosons we arrive at the Bose-Hubbard model in the weakly interacting, low-density regime. The dual problem of p-wave interacting fermions is mapped to the spin-1/2 XXZ model close to the critical point in the highly polarized regime. The mappings are shown to be optimal in the sense that they produce the least error possible for a given discretization length. As an application we examine the ground state of an interacting Fermi gas in a harmonic trap, calculating numerically real-space and momentum-space distributions as well as two-particle correlations. In the analytically known limits the convergence of the results of the lattice model with the continuous one is shown. 16. Tracking unilateral earthquake rupture by P-wave polarization analysis NASA Astrophysics Data System (ADS) Bayer, B.; Kind, R.; Hoffmann, M.; Yuan, X.; Meier, T. 2012-03-01 Rapid estimation of earthquake rupture propagation is essential to declare an early warning for tsunami-generating earthquakes. An increasing number of seismological methods have been developed to determine rupture parameters, such as length, velocity and propagation direction, especially since the occurrence of the Sumatra-Andaman earthquake that resulted in a devastating tsunami in the Indian Ocean region. Here, we present a new method to follow the rupture process in near real time by a polarization analysis of local and regional P phases that permits a faster determination of rupture properties than using teleseismic records. The new technique has the capability to provide detailed information in less than 10 min. Originally, the method stems from a single-station earthquake location method and is expanded here to monitor P-phase polarization variations through time. As the earthquake source moves away from the hypocentre, the backazimuth of an incoming P phase is expected to change accordingly. With polarization analysis we may be able to monitor the temporal change in P-wave backazimuth to follow the rupture process in near real time. Three component P phases are scanned to determine the azimuthal variation as a function of time. The backazimuth of a moving rupture front is determined by the first eigenvector of the covariance matrix. The linearity of the particle motion is used as a measure of the quality of the data. Seismic stations at local and regional distances (?) are used. We tested the new method with a theoretical simulation and observed seismograms of the Sumatra-Andaman earthquake (2004 December 26, Mw= 9.3), and we were able to follow the rupture for the first 200 s. For larger ruptures, stations at more than 30° epicentral distances would be required. The method is also successfully applied to the Wenchuan earthquake (2008 May 12, Mw= 8.0). 17. Supercurrent in a p-wave holographic superconductor SciTech Connect Zeng Huabi [Department of Physics, Nanjing University, Nanjing 210093 (China); Sun Weimin; Zong Hongshi [Department of Physics, Nanjing University, Nanjing 210093 (China); Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing 210093 (China) 2011-02-15 The p-wave and p+ip-wave holographic superconductors with fixed DC supercurrent are studied by introducing a nonvanishing vector potential. We find that close to the critical temperature T{sub c} of zero current, the numerical results of both the p-wave model and the p+ip model are the same as those of Ginzburg-Landau (GL) theory; for example, the critical current is j{sub c}{approx}(T{sub c}-T){sup 3/2} and the phase transition in the presence of a DC current is a first-order transition. Beside the similar results between both models, the p+ip superconductor shows isotropic behavior for the supercurrent, while the p-wave superconductor shows anisotropic behavior for the supercurrent. 18. Shallow three-dimensional P-wave velocity structure revealed by seismic experiment Sakurajima volcano, Japan NASA Astrophysics Data System (ADS) Tameguri, T.; Iguchi, M. 2009-12-01 Sakurajima is a post-caldera cone situated on the southern rim of Aira caldera, south Kyushu, Japan. It consists of two adjoining stratovolcanoes, Kitadake (-13,000 yrs BP) and Minamidake (-5,000 yrs BP). Explosive eruptions have frequently occurred at the summit crater Minamidake since 1955. Main magma reservoir is estimated at a depth of 10 km near the center of the Aira caldera and a minor reservoir is located at shallow (5 km) beneath the Minamidake (Eto, 1991). The two reservoirs are possibly connected by a tensile fault of strike NE-SW as inferred from hypocenter distributions and source mechanisms of VT earthquakes and geodetic data (Hidayati et al., 2007). Seismic experiment was carried in November, 2008 in order to investigate seismic velocity structure, location of magma storage and magma path from the chamber beneath the Aira caldera to the crater of Sakurajima volcano. In the seismic experiment, we used 15 shot points of dynamite and installed about 640 temporary seismic stations. Three-dimensional P-wave velocity structure beneath the Sakurajima volcano is estimated using 3400 arrival times of the first motions from large 8 shots. A high velocity anomaly (+10 % from initial structure) at sea level is detected at north part of the active crater and velocity around mountain body is lower than 2.1 km/s. This high velocity may correspond to old mountain body of the Kitadake. A high velocity anomaly (+15 %) and a low velocity anomaly (-10 %) are found in SSE and NE parts of the crater at the depth of 2 km, respectively. Gravity survey showed that high and low gravity anomalies at SE and NE parts of Sakurajima, respectively (Komazawa et al., 2008). The seismic velocity structure is consistent with the anomalies of the gravity research. The low velocity anomaly at NE part at the depth of 2 km may be related to magma path from the reservoir beneath the Aira caldera to the Minamidake crater, because tensile fault across the volcano from magma reservoir beneath the Aira caldera (Hidayati et al., 2007) is located beneath the low velocity anomaly. 19. 3D P-Wave Velocity Structure of the Deep Galicia Rifted Margin NASA Astrophysics Data System (ADS) Bayrakci, Gaye; Minshull, Timothy; Davy, Richard; Sawyer, Dale; Klaeschen, Dirk; Papenberg, Cord; Reston, Timothy; Shillington, Donna; Ranero, Cesar 2015-04-01 The combined wide-angle reflection-refraction and multi-channel seismic (MCS) experiment, Galicia 3D, was carried out in 2013 at the Galicia rifted margin in the northeast Atlantic Ocean, west of Spain. The main geological features within the 64 by 20 km (1280 km²) 3D box investigated by the survey are the peridotite ridge (PR), the fault bounded, rotated basement blocks and the S reflector, which has been interpreted to be a low angle detachment fault. 44 short period four-component ocean bottom seismometers and 28 ocean bottom hydrophones were deployed in the 3D box. 3D MCS profiles sampling the whole box were acquired with two airgun arrays of 3300 cu.in. fired alternately every 37.5 m. We present the results from 3D first-arrival time tomography that constrains the P-wave velocity in the 3D box, for the entire depth sampled by reflection data. Results are validated by synthetic tests and by the comparison with Galicia 3D MCS lines. The main outcomes are as follows: 1- The 3.5 km/s iso-velocity contour mimics the top of the acoustic basement observed on MCS profiles. Block bounding faults are imaged as velocity contrasts and basement blocks exhibit 3D topographic variations. 2- On the southern profiles, the top of the PR rises up to 5.5 km depth whereas, 20 km northward, its basement expression (at 6.5 km depth) nearly disappears. 3- The 6.5 km/s iso-velocity contour matches the topography of the S reflector where the latter is visible on MCS profiles. Within a depth interval of 0.6 km (in average), velocities beneath the S reflector increase from 6.5 km/s to 7 km/s, which would correspond to a decrease in the degree of serpentinization from ~45 % to ~30 % if these velocity variations are caused solely by variations in hydration. At the intersections between the block bounding normal faults and the S reflector, this decrease happens over a larger depth interval (> 1 km), suggesting that faults act as conduit for the water flow in the upper mantle. 20. 3D P-Wave Velocity Structure of the Deep Galicia Rifted Margin NASA Astrophysics Data System (ADS) Bayrakci, G.; Minshull, T. A.; Davy, R. G.; Sawyer, D. S.; Klaeschen, D.; Papenberg, C. A.; Reston, T. J.; Shillington, D. J.; Ranero, C. R. 2014-12-01 The combined wide-angle reflection-refraction and multi-channel seismic (MCS) experiment, Galicia 3D, was carried out in 2013 at the Galicia rifted margin in the northeast Atlantic Ocean, west of Spain. The main geological features within the 64 by 20 km (1280 km²) 3D box investigated by the survey are the peridotite ridge (PR), the fault bounded, rotated basement blocks and the S reflector, which has been interpreted to be a low angle detachment fault. 44 short period four-component ocean bottom seismometers and 28 ocean bottom hydrophones were deployed in the 3D box. 3D MCS profiles sampling the whole box were acquired with two airgun arrays of 3300 cu.in. fired alternately every 37.5 m. We present the results from 3D first-arrival time tomography that constrains the P-wave velocity in the 3D box, for the entire depth sampled by reflection data. Results are validated by synthetic tests and by the comparison with Galicia 3D MCS lines. The main outcomes are as follows: 1- The 3.5 km/s iso-velocity contour mimics the top of the acoustic basement observed on MCS profiles. Block bounding faults are imaged as velocity contrasts and basement blocks exhibit 3D topographic variations. 2- On the southern profiles, the top of the PR rises up to 5.5 km depth whereas, 20 km northward, its basement expression (at 6.5 km depth) nearly disappears. 3- The 6.5 km/s iso-velocity contour matches the topography of the S reflector where the latter is visible on MCS profiles. Within a depth interval of 0.6 km (in average), velocities beneath the S reflector increase from 6.5 km/s to 7 km/s, which would correspond to a decrease in the degree of serpentinization from ~45 % to ~30 % if these velocity variations are caused solely by variations in hydration. At the intersections between the block bounding normal faults and the S reflector, this decrease happens over a larger depth interval (> 1 km), suggesting that faults act as conduit for the water flow in the upper mantle. 1. Memory of the Lake Rotorua catchment - time lag of the water in the catchment and delayed arrival of contaminants from past land use activities NASA Astrophysics Data System (ADS) Morgenstern, Uwe; Daughney, Christopher J.; Stewart, Michael K.; McDonnell, Jeffrey J. 2013-04-01 The transit time distribution of streamflow is a fundamental descriptor of the flowpaths of water through a catchment and the storage of water within it, controlling its response to landuse change, pollution, ecological degradation, and climate change. Significant time lags (catchment memory) in the responses of streams to these stressors and their amelioration or restoration have been observed. Lag time can be quantified via water transit time of the catchment discharge. Mean transit times can be in the order of years and decades (Stewart et al 2012, Morgenstern et al., 2010). If the water passes through large groundwater reservoirs, it is difficult to quantify and predict the lag time. A pulse shaped tracer that moves with the water can allow quantification of the mean transit time. Environmental tritium is the ideal tracer of the water cycle. Tritium is part of the water molecule, is not affected by chemical reactions in the aquifer, and the bomb tritium from the atmospheric nuclear weapons testing represents a pulse shaped tracer input that allows for very accurate measurement of the age distribution parameters of the water in the catchment discharge. Tritium time series data from all catchment discharges (streams and springs) into Lake Rotorua, New Zealand, allow for accurate determination of the age distribution parameters. The Lake Rotorua catchment tritium data from streams and springs are unique, with high-quality tritium data available over more than four decades, encompassing the time when the bomb-tritium moved through the groundwater system, and from a very high number of streams and springs. Together with the well-defined tritium input into the Rotorua catchment, this data set allows for the best understanding of the water dynamics through a large scale catchment, including validation of complicated water mixing models. Mean transit times of the main streams into the lake range between 27 and 170 years. With such old water discharging into the lake, most of the water inflows into the lake are not yet fully representing the nitrate loading in their sub-catchments from current land use practises. These water inflows are still 'diluted' by pristine old water, but over time, the full amount of nitrate load will arrive at the lake. With the age distribution parameters, it is possible to predict the increase in nitrate load to the lake via the groundwater discharges. All sub-catchments have different mean transit times. The mean transit times are not necessarily correlated with observable hydrogeologic properties like hydraulic conductivity and catchment size. Without such age tracer data, it is therefore difficult to predict mean transit times (lag times, memory) of water transfer through catchments. References: Stewart, M.K., Morgenstern, U., McDonnell, J.J., Pfister, L. (2012). The 'hidden streamflow' challenge in catchment hydrology: A call to action for streamwater transit time analysis. Hydrol. Process. 26,2061-2066, Invited commentary. DOI: 10.1002/hyp.9262 Morgenstern, U., Stewart, M.K., and Stenger, R. (2010) Dating of streamwater using tritium in a post nuclear bomb pulse world: continuous variation of mean transit time with streamflow, Hydrol. Earth Syst. Sci, 14, 2289-2301 2. 14 CFR 93.23 - Arrival Authorizations. Code of Federal Regulations, 2011 CFR 2011-01-01 ...AIR TRAFFIC RULES Congestion and Delay Reduction at Chicago O'Hare International...following factors: (1) The number of delays; (2) The length of delays; (3) Weather conditions; (4) On-time arrivals and departures; (5)... 3. 14 CFR 93.23 - Arrival Authorizations. Code of Federal Regulations, 2010 CFR 2010-01-01 ...AIR TRAFFIC RULES Congestion and Delay Reduction at Chicago O'Hare International...following factors: (1) The number of delays; (2) The length of delays; (3) Weather conditions; (4) On-time arrivals and departures; (5)... 4. Tomographic imaging of local earthquake delay times for three-dimensional velocity variation in western Washington Microsoft Academic Search Jonathan M. Lees; Robert S. Crosson 1990-01-01 Tomographic inversion is applied to delay times from local earthquakes to image three dimensional velocity variations in the Puget Sound region of western Washington. The 37,500 square km region is represented by nearly cubic blocks of 5 km per side. P-wave arrival time observations from 4,387 crustal earthquakes, with depths of 0 to 40 km, were used as sources producing 5. Tomographic imaging of local earthquake delay times for three-dimensional velocity variation in Western Washington Microsoft Academic Search Jonathan M. Lees; Roberts S. Crosson 1990-01-01 Tomographic inversion is applied to delay times from local earthquakes to image three dimensional velocity variations in the Puget Sound region of Western Washington. The 37,500 square km region is represented by nearly cubic blocks of 5 km per side. P-wave arrival time observations from 4,387 crustal earthquakes, with depths of 0 to 40 km, were used as sources producing 6. Crust and upper mantle P wave velocity structure beneath Valles caldera, New Mexico: Results from the Jemez teleseismic tomography experiment SciTech Connect Steck, Lee K.; Fehler, Michael C.; Roberts, Peter M.; Baldridge, W. Scott; Stafford, Darrik G. [Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico (United States)] [Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Lutter, William J.; Sessions, Robert [Department of Geology and Geophysics, University of Wisconsin-Madison (United States)] [Department of Geology and Geophysics, University of Wisconsin-Madison (United States) 1998-10-01 New results are presented from the teleseismic component of the Jemez Tomography Experiment conducted across Valles caldera in northern New Mexico. We invert 4872 relative {ital P} wave arrival times recorded on 50 portable stations to determine velocity structure to depths of 40 km. The three principle features of our model for Valles caldera are: (1) near-surface low velocities of {minus}17{percent} beneath the Toledo embayment and the Valle Grande, (2) midcrustal low velocities of {minus}23{percent} in an ellipsoidal volume underneath the northwest quadrant of the caldera, and (3) a broad zone of low velocities ({minus}15{percent}) in the lower crust or upper mantle. Crust shallower than 20 km is generally fast to the northwest of the caldera and slow to the southeast. Near-surface low velocities are interpreted as thick deposits of Bandelier tuff and postcaldera volcaniclastic rocks. Lateral variation in the thickness of these deposits supports increased caldera collapse to the southeast, beneath the Valle Grande. We interpret the midcrustal low-velocity zone to contain a minimum melt fraction of 10{percent}. While we cannot rule out the possibility that this zone is the remnant 1.2 Ma Bandelier magma chamber, the eruption history and geochemistry of the volcanic rocks erupted in Valles caldera following the Bandelier tuff make it more likely that magma results from a new pulse of intrusion, indicating that melt flux into the upper crust beneath Valles caldera continues. The low-velocity zone near the crust-mantle boundary is consistent with either partial melt in the lower crust or mafic rocks without partial melt in the upper mantle. In either case, this low-velocity anomaly indicates that underplating by mantle-derived melts has occurred. {copyright} 1998 American Geophysical Union 7. Crustal structure beneath Long Valley caldera from modeling of teleseismic P wave polarizations and Ps converted waves SciTech Connect Steck, L.K. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States); Prothero, W.A. Jr. [Univ. of California, Santa Barbara, CA (United States)] [Univ. of California, Santa Barbara, CA (United States) 1994-04-10 In this study, the authors present new constraints on the nature of the low-velocity zone beneath Long Valley caldera, based on the measured propagation directions of teleseismic P waves and on modeling of P to S converted waves. The low-velocity body is a large asymmetrical volume which deepens to the east, extending from depths of 7 to 30 km. It contains lower velocities than originally proposed by earlier teleseismic studies. In particular, there is a tabular feature between 7 and 11 km depth that has a reduction in velocity of about 30%. These low velocities imply a much greater percentage of melt in the crust beneath Long Valley caldera than previously estimated. Array analysis of large delayed arrivals identifies them to be Ps converted waves from the shoulders and roof of this tabular zone. These conversions bound the depth to the magma chamber roof to be within about 10 km of the surface. These results are consistent with elements from several other studies, and the authors present an integrated and improved model of crustal structure at Long Valley. The concordance of the deeper low-velocity zones with regional structural trends implies that the shallow low-velocity feature is a cupola on top of an asymmetric diapiric ridge rising up from the migmatized lower crust of the Basin and Range. The authors present two contrasting interpretations of the geometry of low-velocity zones in the crust: one implies a time-invariant magma chamber and conduit system for Long Valley caldera, the other implies an evolution of that system from a simple vertical regime to its current asymmetrical geometry. 37 refs., 19 figs., 1 tab. 8. P-wave attenuation tomography of Mount St. Helens: preliminary results from coda-normalized spectra NASA Astrophysics Data System (ADS) de Siena, L.; Hicks, S.; Waite, G. P.; Moran, S. C. 2010-12-01 The P-wave velocity structure of Mount St. Helens has been recently imaged with local earthquake tomography, using the data recorded since its eruption in 1980. Part of this dataset has been processed to obtain a preliminary frequency dependent Qp image of the crust below the volcanic cone. We extended the so-called coda-normalization method, usually applied to S-waves, to the measurement of path-dependent P-wave attenuation. A scattering model has been developed in order to select the best time-window to measure the P-wave spectral amplitude on each trace. The objective is to average the effect of the source radiation pattern with the properties of early coda. The weighting matrix in the final inversion is dependent on the source radiation pattern and the spectral amplitude of noise. The Discrete Picard Condition and the Discrepancy Principle have been applied to investigate the maximum resolution available in each part of the medium. Truncated Singular Value Decomposition as well as Zeroth-, first- and second-order Tikhonov regularization techniques have been investigated by using the multi-resolution inversion code (MuReATA). The interpretation of the preliminary results is carried out by using cluster analysis on velocity and attenuation measurements. 9. Estimating Seismic Moment From Broadband P-Waves for Tsunami Warnings. NASA Astrophysics Data System (ADS) Hirshorn, B. F. 2006-12-01 The Richard H. Hagemeyer Pacific Tsunami Warning Center (PTWC), located in Ewa Beach, Oahu, Hawaii, is responsible for issuing local, regional, and distant tsunami warnings to Hawaii, and for issuing regional and distant tsunami warnings to the rest of the Pacific Basin, exclusive of the US West Coast. The PTWC must provide these tsunami warnings as soon as technologically possible, based entirely on estimates of a potentially tsunamigenic earthquake's source parameters. We calculate the broadband P-wave moment magnitude, Mwp, from the P or pP wave velocity seismograms [Tsuboi et al., 1995, 1999]. This method appears to work well for regional and teleseismic events [ Tsuboi et al (1999], Whitmore et al (2002), Hirshorn et al (2004) ]. Following Tsuboi, [1995], we consider the displacement record of the P-wave portion of the broadband seismograms as an approximate source time function and integrate this record to obtain the moment rate function, Mo(t), and the moment magnitude [Hanks and Kanamori, 1972] as a function of time, Mw(t). We present results for Mwp for local, regional, and teleseismic broad band recordings for earthquakes in the Mw 5 to 9.3 range. As large Hawaii events are rare, we tested this local case using other Pacific events in the magnitude 5.0 to 7.5 range recorded by nearby stations. Signals were excluded, however, if the epicentral distance was so small (generally less than 1 degree) that there was contamination by the S-wave too closely following the P-waves. Scatter plots of Mwp against the Harvard Mw for these events shows that Mwp does predict Mw well from seismograms recorded at local, regional, and teleseismic distances. For some complex earthquakes, eg. the Mw 8.4(HRV) Peru earthquake of June 21, 2001, Mwp underestimates Mw if the first moment release is not the largest. Our estimates of Mwp for the Mw 9.3 Summatra-Andaman Island's earthquake of December 26, 2004 and for the Mw 8.7 (HRV) Summatra event of March 28, 2005, were Mwp 8.1, Mwp 8.7 respectively, from p-waves recorded at 15 - 90 degrees from each hypocenter. 10. Holographic p-wave superconductors from Gauss-Bonnet gravity SciTech Connect Cai Ronggen; Nie Zhangyu; Zhang Haiqing [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China) 2010-09-15 We study the holographic p-wave superconductors in a five-dimensional Gauss-Bonnet gravity with an SU(2) Yang-Mills gauge field. In the probe approximation, we find that when the Gauss-Bonnet coefficient grows, the condensation of the vector field becomes harder, both the perpendicular and parallel components, with respect to the direction of the condensation, of the anisotropic conductivity decrease. We also study the mass of the quasiparticle excitations, the gap frequency and the DC conductivities of the p-wave superconductor. All of them depend on the Gauss-Bonnet coefficient. In addition, we observe a strange behavior for the condensation and the relation between the gap frequency and the mass of quasiparticles when the Gauss-Bonnet coefficient is larger than 9/100, which is the upper bound for the Gauss-Bonnet coefficient from the causality of the dual field theory. 11. P-wave baryons in the quark model Microsoft Academic Search Nathan Isgur; Gabriel Karl 1978-01-01 We discuss the spectrum and mixing angles of negative-parity baryons in a quark-model framework inspired by quantum chromodynamics. We take into account in zero order the removal of the degeneracy between the two P-wave states of the three-quark system in the S=-1 sector, as well as the hyperfine interaction between quarks, but neglect spin-orbit coupling. We find good agreement with 12. Decays rates for S- and P-wave bottomium SciTech Connect Bodwin, G.T.; Kim, S.; Sinclair, D.K. 1994-11-01 The authors use the Bodwin-Braaten-Lepage factorization scheme to separate the long- and short-distance factors that contribute to the decay rates of {Upsilon}, {eta}{sub b} (S-wave) and {chi}{sub b},h{sub b} (P-wave). The long distance matrix elements are calculated on the lattice in the quenched approximation using a non-relativistic formulation of the b quark dynamics. 13. Electrocardiographic P-wave characteristics in patients with psoriasis vulgaris PubMed Central Erdogan, Ercan; Tasal, Abdurrrahman; Vatankulu, Mehmet Akif; Kul, Seref; Sevgili, Emrah; Ertas, Gokhan; Dizman, Didem; Onsun, Nahide; Uysal, Omer 2013-01-01 Purpose Psoriasis vulgaris is one of the most common skin disorders. Patients with psoriasis carry an excessive risk of atrial fibrillation (AF). The differences between the maximum (Pmax) and the minimum (Pmin) P-wave duration on ECG are defined as P-wave dispersion (PWD). Prolongation of PWD is an independent risk factor for the development of AF. The aim of this the study was to investigate P-wave duration and PWD in patients with psoriasis. Methods Sixty-one adult patients with psoriasis vulgaris (group 1) and 58 age and sex-matched healthy individuals (group 2) were included in this study. ECG recordings were obtained, and the P-wave variables were calculated. Results were reported as mean ± standard deviation and percentages. Continuous variables were analysed using Student's t test. A value of P < 0.05 was considered statistically signi?cant. Results Pmax and PWD were significantly higher in group 1 than in group 2 (108.8 ± 21.3 ms versus 93.3 ± 13.0 ms, P < 0.001; 67.4 ± 22.9 ms versus 45.0 ± 19.6 ms, P < 0.001, respectively). Also, Pmin was significantly lower in group 1 (41.3 ± 12.3 ms versus 48.3 ± 14.3 ms, P = 0.04). The psoriasis disease activity score and hsCRP correlated with PWD (P < 0.01). Conclusions Atrial conduction of sinus impulses was impaired in patients with psoriasis vulgaris. It was more prominent in patients with severe disease. Physicians caring for patients with psoriasis vulgaris should screen them for AF development. PMID:23153368 14. Kondo resonance from p-wave hybridization in graphene. PubMed Jafari, S A; Tohyama, T 2014-10-15 The p-wave hybridization in graphene present a distinct class of Kondo problem in pseudogap Fermi systems with bath density of states (DOS) ??(?) ? |?|. The peculiar geometry of substitutional and hollow-site ad-atoms, and effectively the vacancies allow for a p-wave form of momentum dependence in the hybridization of the associated local orbital with the Dirac fermions of the graphene host which results in a different picture than the s-wave momentum independent hybridization. For the p-wave hybridization function, away from the Dirac point we find closed-form formulae for the Kondo temperature TK which in contrast to the s-wave case is non-zero for any value of hybridization strength V of the single impurity Anderson model (SIAM). At the Dirac point where the DOS vanishes, we find a conceivably small value of Vmin above which the Kondo screening takes place even in the presence of particle-hole symmetry. We also show that the non-Lorentzian line shape of the local spectrum arising from anomalous hybridization function leads to much larger TK in vacant graphene compared to a metallic host with similar bandwidth and SIAM parameters. PMID:25237820 15. Kondo resonance from p-wave hybridization in graphene NASA Astrophysics Data System (ADS) Jafari, S. A.; Tohyama, T. 2014-10-01 The p-wave hybridization in graphene present a distinct class of Kondo problem in pseudogap Fermi systems with bath density of states (DOS) ?0(?) ? |?|. The peculiar geometry of substitutional and hollow-site ad-atoms, and effectively the vacancies allow for a p-wave form of momentum dependence in the hybridization of the associated local orbital with the Dirac fermions of the graphene host which results in a different picture than the s-wave momentum independent hybridization. For the p-wave hybridization function, away from the Dirac point we find closed-form formulae for the Kondo temperature TK which in contrast to the s-wave case is non-zero for any value of hybridization strength V of the single impurity Anderson model (SIAM). At the Dirac point where the DOS vanishes, we find a conceivably small value of Vmin above which the Kondo screening takes place even in the presence of particle–hole symmetry. We also show that the non-Lorentzian line shape of the local spectrum arising from anomalous hybridization function leads to much larger TK in vacant graphene compared to a metallic host with similar bandwidth and SIAM parameters. 16. p-wave optical Feshbach resonances in {sup 171}Yb SciTech Connect Goyal, Krittika; Deutsch, Ivan [Center for Quantum Information and Control, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Reichenbach, Iris [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, D-01187 Dresden (Germany) 2010-12-15 We study the use of an optical Feshbach resonance to modify the p-wave interaction between ultracold polarized {sup 171}Yb spin-1/2 fermions. A laser exciting two colliding atoms to the {sup 1}S{sub 0}+{sup 3}P{sub 1} channel can be detuned near a purely-long-range excited molecular bound state. Such an exotic molecule has an inner turning point far from the chemical binding region, and thus, three-body recombination in the Feshbach resonance will be highly suppressed in contrast to that typically seen in a ground-state p-wave magnetic Feshbach resonance. We calculate the excited molecular bound-state spectrum using a multichannel integration of the Schroedinger equation, including an external perturbation by a magnetic field. From the multichannel wave functions, we calculate the Feshbach resonance properties, including the modification of the elastic p-wave scattering volume and inelastic spontaneous scattering rate. The use of magnetic fields and selection rules for polarized light yields a highly controllable system. We apply this control to propose a toy model for three-color superfluidity in an optical lattice for spin-polarized {sup 171}Yb, where the three colors correspond to the three spatial orbitals of the first excited p band. We calculate the conditions under which tunneling and on-site interactions are comparable, at which point quantum critical behavior is possible. 17. GPS/Loran-C interoperability for time and frequency applications: A survey of the times of arrival of Loran-C transmissions via GPS common mode/common view satellite observations NASA Technical Reports Server (NTRS) Penrod, Bruce; Funderburk, Richard; Dana, Peter 1990-01-01 The results from this survey clearly indicate that the Global Positioning System (GPS) time transfer capability is superior to that of the Loran-C system for absolute timing accuracy, and that even with the most careful calibration of the Loran-C receiver delay and propagation path, inexplicable time of arrival (TOA) biases remain which are larger than the variations across all of the transmitters. Much more data covering years would be needed to show that these biases were stable enough to be removed with a one time site calibration. The synchronization of the transmissions is excellent, all showing low parts in 10(exp 13) offsets versus the United States Naval Observatory (USNO) master clock. With the exception of the Searchlight transmitter, all of the transmissions exhibit timing stabilities over the entire period of less than 300 ns RMS which is at the observed levels of GPS under selective availability (SA). The Loran-C phase instabilities take place over a much greater time interval than those being forced onto the GPS signals under SA, providing for better medium to short term frequency stability. Data show that all but the most distant transmitters offer better than three parts in 10(exp 11) stability at this averaging time. It is in the frequency control area where GPS/Loran-C interoperation will offer some synergistic advantages over GPS alone under SA. 18. Joint Inversion of Body-Wave Arrival Times and Surface-Wave Dispersion Data for Three-Dimensional Seismic Velocity Structure Around SAFOD NASA Astrophysics Data System (ADS) Zhang, H.; Thurber, C. H.; Maceira, M.; Roux, P. 2013-12-01 The crust around the San Andreas Fault Observatory at depth (SAFOD) has been the subject of many geophysical studies aimed at characterizing in detail the fault zone structure and elucidating the lithologies and physical properties of the surrounding rocks. Seismic methods in particular have revealed the complex two-dimensional (2D) and three-dimensional (3D) structure of the crustal volume around SAFOD and the strong velocity reduction in the fault damage zone. In this study we conduct a joint inversion using body-wave arrival times and surface-wave dispersion data to image the P-and S-wave velocity structure of the upper crust surrounding SAFOD. The two data types have complementary strengths - the body-wave data have good resolution at depth, albeit only where there are crossing rays between sources and receivers, whereas the surface waves have very good near-surface resolution and are not dependent on the earthquake source distribution because they are derived from ambient noise. The body-wave data are from local earthquakes and explosions, comprising the dataset analyzed by Zhang et al. (2009). The surface-wave data are for Love waves from ambient noise correlations, and are from Roux et al. (2011). The joint inversion code is based on the regional-scale version of the double-difference (DD) tomography algorithm tomoDD. The surface-wave inversion code that is integrated into the joint inversion algorithm is from Maceira and Ammon (2009). The propagator matrix solver in the algorithm DISPER80 (Saito, 1988) is used for the forward calculation of dispersion curves from layered velocity models. We examined how the structural models vary as we vary the relative weighting of the fit to the two data sets and in comparison to the previous separate inversion results. The joint inversion with the 'optimal' weighting shows more clearly the U-shaped local structure from the Buzzard Canyon Fault on the west side of SAF to the Gold Hill Fault on the east side. 19. Joint Inversion of Body-Wave Arrival Times and Surface-Wave Dispersion Data in the Wavelet Domain Constrained by Sparsity Regularization NASA Astrophysics Data System (ADS) Zhang, H.; Fang, H.; Yao, H.; Maceira, M.; van der Hilst, R. D. 2014-12-01 Recently, Zhang et al. (2014, Pure and Appiled Geophysics) have developed a joint inversion code incorporating body-wave arrival times and surface-wave dispersion data. The joint inversion code was based on the regional-scale version of the double-difference tomography algorithm tomoDD. The surface-wave inversion part uses the propagator matrix solver in the algorithm DISPER80 (Saito, 1988) for forward calculation of dispersion curves from layered velocity models and the related sensitivities. The application of the joint inversion code to the SAFOD site in central California shows that the fault structure is better imaged in the new model, which is able to fit both the body-wave and surface-wave observations adequately. Here we present a new joint inversion method that solves the model in the wavelet domain constrained by sparsity regularization. Compared to the previous method, it has the following advantages: (1) The method is both data- and model-adaptive. For the velocity model, it can be represented by different wavelet coefficients at different scales, which are generally sparse. By constraining the model wavelet coefficients to be sparse, the inversion in the wavelet domain can inherently adapt to the data distribution so that the model has higher spatial resolution in the good data coverage zone. Fang and Zhang (2014, Geophysical Journal International) have showed the superior performance of the wavelet-based double-difference seismic tomography method compared to the conventional method. (2) For the surface wave inversion, the joint inversion code takes advantage of the recent development of direct inversion of surface wave dispersion data for 3-D variations of shear wave velocity without the intermediate step of phase or group velocity maps (Fang et al., 2014, Geophysical Journal International). A fast marching method is used to compute, at each period, surface wave traveltimes and ray paths between sources and receivers. We will test the new joint inversion code at the SAFOD site to compare its performance over the previous code. We will also select another fault zone such as the San Jacinto Fault Zone to better image its structure. 20. Estimation of Electro-Magnetic Signals Generated by Stress Changes before the Arrival of Seismic Waves NASA Astrophysics Data System (ADS) Yamazaki, K. 2014-12-01 This work aims to increase the efficiency of earthquake early warning (EEW) systems. Conventional EEW systems detect occurrence of earthquakes by means of detecting seismic P-waves; thus, they cannot make alert before P-waves reach the ground surface in principle. If we desires to break this limitation, we must observe other physical quantities including the electromagnetic (EM) and gravitational fields, variations of which propagate faster than elastic waves. The present study focuses on changes in the magnetic field generated by co-seismic stress changes in the Earth's crust. When magnetic minerals in the Earth's crust are subjected to mechanical forces, increments or decrements of magnetization appear. This is called the piezomagnetic effect. Significant changes in values of the geomagnetic field has frequently observed between before and after major earthquakes or volcanic ground deformation, which is considered to be generated by the piezomagnetic effect. The problem is, however, whether or not co-seismic changes in the stress field generates earlier signals, that is, changes in the magnetic field at observation sites which occur before arrival of seismic waves. To answer the question, a set of equations governing elastodynamics, electromagnetics, and the piezomagnetic effect, are solved for a whole space stuffed with a uniform physical properties. An impulsive double couple is assumed to represent the earthquake source mechanism. A set of solutions is derived in time-domain, and its features are investigated for several sets of parameters including electrical conductivity and seismic velocities. We can confirm that there are certain amount of changes in the EM field, even before arrival of seismic waves. EM signals before arrival of seismic waves (i.e. earlier EM signals) are relatively large in the case that the Earth's crust is conductive (> 0.01 S/m). However, the appearance of relatively large EM signal is not simultaneous to the rupture; instead, it is only after seismic waves approach the observation site. This result means detection of earthquakes by means of observing piezomagnetic signals is not easy at present in general, although it will be possible if sensitivity of EM sensors improves. 1. Observing Majorana bound States in p-Wave Superconductors Using Noise Measurements in Tunneling Experiments E-print Network Demler, Eugene are interested in the case of p-wave chiral superconductors (i.e., with an order parameter of the type ^px i ^py3) [4]. Superconductors with p-wave orbital symmetry have spin-triplet pairing, and the orderObserving Majorana bound States in p-Wave Superconductors Using Noise Measurements in Tunneling 2. Original Article Assessment of the P Wave Dispersion and Duration in Elite Women Basketball Players Microsoft Academic Search Gokhan Metin; Mustafa Yildiz; Bulent Bayraktar; Ilker Yucesir; Hasan Kasap; Lutfi Cakar Background: P wave dispersion is an independent predictor of atrial fibrillation. P wave dispersion is associated with inhomogeneous and discontinuous propagation of sinus impulses. The purpose of this study was to investigate P wave dispersion and transthoracic echocardiographic findings in elite women basketball players. Methods: We recruited 27 well-trained woman athletes with a training history of many years (11.9 ± 3. First in line or first in time? Effects of settlement order and arrival date on reproduction in a group-living beetle Dendroctonus ponderosae. PubMed Latty, Tanya M; Reid, Mary L 2009-05-01 1. In group-living organisms, individuals that initiate aggregations, termed pioneers, may suffer higher mortality costs than individuals that join established aggregations. Here we examine the hypothesis that aggregation initiators achieve higher reproductive success in the early phases of colonization, potentially through lower competition and increased access to the resource (finder's advantage), and that this benefit is sufficient to outweigh the costs of pioneering. 2. We also examine the role of arrival date (irrespective of order within the aggregation) on reproductive success, because individuals in seasonal environments may gain an advantage by arriving early. We test these hypotheses using mountain pine beetles, Dendroctonus ponderosae (Coleoptera: Curculionidae, Scolytinae), an obligately aggregating insect wherein pioneers suffer high mortality due to tree defences. We measured reproductive success at the start of winter when most components of final offspring number were likely to be determined. 3. Surviving pioneers that successfully recruited conspecifics had smaller broods than individuals that joined aggregations, refuting our hypothesis. The later that a beetle settled within an aggregation, the higher its reproductive success. However, beetles that settled early in the season produced more offspring than those that settled later in the season, and this effect was generally stronger than settlement order within an aggregation. Our study highlights the importance of examining the effects of both settlement order and arrival date on the costs and benefits of pioneering aggregations. PMID:19292705 4. Quasi-Newton inversion of seismic first arrivals using source finite1 bandwidth assumption: application to landslides characterization2 E-print Network Boyer, Edmond , Samyn et al. (2011) used a 3D seismic refraction traveltime52 tomography to provide a valuableMarillier (2000) interpreted the late arrivals of P-waves to image the bedrock geometry48 using seismic reflection and continuous representation of the 3D structure and geology of a53 landslide. Grandjean et al. (2007 5. Vortex with Fractional Quantum Numbers in Chiral p-Wave Superconductor E-print Network J. Goryo 1999-11-10 We show that a vortex in a chiral p-wave superconductor, which has the p_{x}+ i p_{y}-wave pairing state and breaks U(1), parity and time reversal symmetry simultaneously, has fractional charge -{n e}/{4} and fractional angular momentum -n^{2}/{16} (n; vorticity). This suggests that the vortex could be anyon and could obey fractional statistics. Electromagnetic property of the vortex is also discussed and we find that an electric field is induced near the vortex core. 6. p-Wave Cold Collisions in an Optical Lattice Clock SciTech Connect Lemke, N. D.; Sherman, J. A.; Oates, C. W.; Ludlow, A. D. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Stecher, J. von; Rey, A. M. [JILA, NIST, and University of Colorado, Department of Physics, Boulder, Colorado 80309 (United States) 2011-09-02 We study ultracold collisions in fermionic ytterbium by precisely measuring the energy shifts they impart on the atoms' internal clock states. Exploiting Fermi statistics, we uncover p-wave collisions, in both weakly and strongly interacting regimes. With the higher density afforded by two-dimensional lattice confinement, we demonstrate that strong interactions can lead to a novel suppression of this collision shift. In addition to reducing the systematic errors of lattice clocks, this work has application to quantum information and quantum simulation with alkaline-earth atoms. 7. Hydrodynamic Modes of a holographicp-$wave superfluid E-print Network Raul E. Arias; Ignacio Salazar Landea 2014-11-04 In this work we analyze the hydrodynamics of a$p-$wave superfluid on its strongly coupled regime by considering its holographic description. We obtain the poles of the retarded Green function through the computation of the quasi-normal modes of the dual AdS black hole background finding diffusive, pseudo-diffusive and sound modes. For the sound modes we compute the speed of sound and its attenuation as function of the temperature. For the diffusive and pseudo-diffusive modes we find that they acquire a non-zero real part at certain finite momentum. 8. Endstates in multichannel spinless p-wave superconducting wires NASA Astrophysics Data System (ADS) Rieder, M.-T.; Kells, G.; Duckheim, M.; Meidan, D.; Brouwer, P. W. 2012-09-01 Multimode spinless p-wave superconducting wires with a width W much smaller than the superconducting coherence length ? are known to have multiple low-energy subgap states localized near the wire's ends. Here we compare the typical energies of such endstates for various terminations of the wire: A superconducting wire coupled to a normal-metal stub, a weakly disordered superconductor wire and a wire with smooth confinement. Depending on the termination, we find that the energies of the subgap states can be higher or lower than for the case of a rectangular wire with hard-wall boundaries. 9.$ SU(3) $Classification of$ p $-Wave$ ??$and$ ?'?$Systems E-print Network S. U. Chung; E. Klempt; J. G. Körner 2002-11-07 An exotic meson, the$\\pi_1(1400)$with$J^{PC}=1^{-+}$, has been seen to decay into a p-wave$\\eta\\pi$system. If this decay conserves flavor SU(3), then it can be shown that this exotic meson must be a four-quark state ($q\\bar q+q\\bar q$) belonging to a flavor${\\bf10}\\oplus{\\bf\\bar{10}}$representation of SU(3). In contrast, the$\\pi_1(1600)$with a substantial decay mode into$\\eta'\\pi$is likely to be a member of a flavor octet. 10. A Bayesian approach to the detection of temporal changes in P wave velocity Microsoft Academic Search Nobuo Hurukawa; Masajiro Imoto 1989-01-01 On the basis of Akaike's Bayesian information criterion (ABIC), a new method is proposed for detecting a temporal change in a seismic velocity in a source region. The method of joint hypocenter determination was modified in order to determine a seismic velocity in a source layer as a function of time together with hypocenters and station corrections. Arrival times of 11. Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography SciTech Connect Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M. 2012-01-10 In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization. 12. Teleseismic P wave delays and modes of shortening the mantle lithosphere beneath South Island, New Zealand NASA Astrophysics Data System (ADS) Stern, Tim; Molnar, Peter; Okaya, David; Eberhart-Phillips, Donna 2000-09-01 A high-speed zone in the mantle directly beneath the Southern Alps of New Zealand is required by the recorded pattern of teleseismic P waves. Two parallel lines of 80 seismographs spaced at ˜2 km intervals recorded three earthquakes from the western Pacific with epicentral distances of 52°, 53° and 78°. Azimuthal bearings were all within 15 degrees of the mean trends of the seismograph lines. Differences between measured delays and those predicted from the crustal structure reach 0.8 s along one line and 1.0 s along the other, with the rays for the earliest arriving signals passing the depth of ˜120 km beneath the center of the island. Assuming these early arrivals are due to structure within the mantle shallower than 200 km, they imply that the core of the high-speed zone lies beneath the thickest crust, which has been shortened by ˜100 km of convergence during the past 6-7 Myr. Although the shape and position of the high-speed body cannot be fixed uniquely, a roughly symmetric body centered about a depth of 120 km, 80-100 km wide, with a depth extent of 100 km and with a maximum speed advance of ˜7% satisfies the observations. The pattern of residuals does not fit with those predicted by simple models of intracontinental subduction in which crust and mantle lithosphere are detached and one slab of mantle lithosphere underthrusts the other. Rather, the residuals favor thickening of mantle lithosphere by a more homogenous straining of it, as if mantle lithosphere beneath continental crust behaved as a continuum. An excess mass in the mantle is also required by the observed gravity anomalies, once allowance is made for the seismically determined crustal thickness. This high-density mantle anomaly provides sufficient force (per unit length) to maintain the crustal root, which is approximately twice as thick as that necessary to support the topography. 13. Relationship between macro-fracture density, P-wave velocity, and permeability of coal NASA Astrophysics Data System (ADS) Wang, Haichao; Pan, Jienan; Wang, Sen; Zhu, Haitao 2015-06-01 This study was undertaken to determine the quantitative relationship between macro-fracture density, P-wave velocity, porosity and permeability of different coal rank samples from mining areas in North China. The coal sample permeability shows an exponential growth with increasing fracture density. The relation between P-wave velocity and porosity is power function and P-wave velocity decreases with the increasing porosity. P-wave velocity linearly or nonlinearly decreases with the increase of fracture density in the selected coal samples (0.73-3.59% Ro). However, the overall trend is that P-wave velocity decreases with an increase in macro-fracture density. The permeability of coal samples linearly decreases with the increase of P-wave velocity. The quantitative relationship between P-wave velocity and permeability could provide reference for the further study of permeability predicting. 14. Improved P-wave Tomography of the Lowermost Mantle and Consequences for Mantle and Core Dynamics NASA Astrophysics Data System (ADS) Tkalcic, H.; Young, M. K.; Muir, J. B. 2014-12-01 The core mantle boundary (CMB) separates the liquid iron core from the slowly-convecting solid mantle. The ~300 km thick barrier above the boundary has proven to be far more than a simple dividing layer; rather it is a complex region with a range of proposed phenomena such as thermal and compositional heterogeneity, partial melting and anisotropy. Characterizing the heterogeneity in the lowermost mantle through seismic tomography will prove crucial to accurately understanding key geodynamical processes within our planet, not just in the mantle above, but also a possible "mapping" onto the inner core boundary (ICB) through a thermochemical convection in the outer core, which in turn might control the growth of the inner core (e.g. Aubert et al., 2008; Gubbins et al., 2011). Here we obtain high-resolution compressional wave (P-wave) velocity images and uncertainty estimates for the lowermost mantle using travel time data collected by waveform cross-correlation. Strikingly, independent datasets of seismic phases that "see" the lowermost mantle in a different way yield similar P-wave velocity distributions at lower harmonic degrees. We also consider the effect of CMB topography. The images obtained are void of explicit model parameterization and regularization (through transdimensional Bayesian tomography) and contain features on multiple spatial scales. Subsequent spectral analyses reveal a power of heterogeneity three times larger than previous estimates. The P-wave tomograms of the lowermost mantle contain the harmonic degree 2-structure, similar to tomographic images derived from S-wave data (e.g. Ritsema et al. 2011), but with additional higher harmonic degrees (notably, 3-7). In other words, the heterogeneity size is uniformly distributed between about 500 and 6000 km. Inter alia, the resulting heterogeneity spectrum provides a bridge between the long-wavelength features of most global models and the very short-scale dimensions of scatterers mapped in independent studies. We argue that the new images of P-wave velocity in the lowermost mantle, void of explicit parameterization and damping, improve the imaging resolution and provide realistic boundary conditions at the CMB (due to a high sensitivity to heat flux) with important consequences for Earth dynamics. 15. P wave dispersion in obsessive-compulsive disorder PubMed Central Yavuzkir, Mustafa F.; Atmaca, Murad; Gurok, M. Gurkan; Adiyaman, Sahin 2015-01-01 Background: P wave dispersion (Pd) is defined as the difference between the maximum and the minimum P wave duration. It has recently been associated with increased anxiety levels, thereby predisposing affected individuals to fatal heart disease. Despite of evidence of this autonomous nervous system (ANS) relationship, there are no electrocardiography (ECG) studies in the patients with obsessive-compulsive disorder (OCD). Thus, in this study, we aimed to evaluate the Pd in OCD patients. Materials and Methods: The study consisted of a total of 25 patients with OCD and same number of physically and mentally healthy age- and gender-matched controls. For psychological testing, Yale-Brown Obsession and Compulsion (Y-BOCS) was administered. Results: Pmax was found to be significantly higher in the patients compared to controls. Pmin did not differ between groups. Left atrium sizes were not different between groups. As for the main parameter investigated in the present study, it was found that Pd was significantly increased in the OCD patients than the controls. Y-BOCS scores for the patient group was positively correlated with Pd (r = 0.73, P < 0.01). Conclusions: In conclusion, our results suggest that Pd may be associated with OCD though our sample is too small to allow us to obtain a clear conclusion. Future studies with larger sample evaluating the effects of treatment are required. 16. Rupture history of the 1997 Cariaco, Venezuela, earthquake from teleseismic P waves USGS Publications Warehouse Mendoza, C. 2000-01-01 A two-step finite-fault waveform inversion scheme is applied to the broadband teleseismic P waves recorded for the strike-slip, Cariaco, Venezuela, earthquake of 9 July 1997 to recover the distribution of mainshock slip. The earthquake is first analyzed using a long narrow fault with a maximum rise time of 20 sec. This line-source analysis indicates that slip propagated to the west with a constant rupture velocity and a relatively short rise time. The results are then used to constrain a second inversion of the P waveforms using a 60-km by 20-km two-dimensional fault. The rupture shows a zone of large slip (1.3-m peak) near the hypocenter and a second, broader source extending updip and to the west at depths shallower than 5 km. The second source has a peak slip of 2.1 meters and accounts for most of the moment of 1.1 × 1026 dyne-cm (6.6 Mww) estimated from the P waves. The inferred rupture pattern is consistent with macroseismic effects observed in the epicentral area. 17. Search for double charmonium decays of the P-wave spin-triplet bottomonium states E-print Network Shen, C P; Iijima, T 2012-01-01 Using a sample of 158 million$\\Upsilon(2S)$events collected with the Belle detector, we search for the first time for double charmonium decays of the$P$-wave spin-triplet bottomonium states ($\\Upsilon(2S) \\to \\gamma \\chi_{bJ}$,$\\chi_{bJ} \\to \\jpsi \\jpsi$,$\\jpsi \\psp$,$\\psp \\psp$for J=0, 1, and 2). No significant$\\chi_{bJ}$signal is observed in the double charmonium mass spectra, and we obtain the following upper limits,$\\BR(\\chi_{bJ} \\to \\jpsi \\jpsi)psp)psp \\psp)<3.1\\times 10^{-5}$,$6.2\\times 10^{-5}$,$1.6\\times 10^{-5}$for J=0, 1, and 2, respectively, at the 90% confidence level. These limits are significantly lower than the central values (with uncertainties of 50% to 70%) predicted using the light cone formalism but are consistent with calculations using the NRQCD factorization approach. 18. Non-topological nature of the edge current in a chiral p-wave superconductor NASA Astrophysics Data System (ADS) Taylor, Edward; Huang, Wen; Lederer, Samuel; Kallin, Catherine 2015-03-01 The edges of time reversal symmetry breaking topological superconductors support chiral Majorana bound states as well as spontaneous charge currents. The Majorana modes are a robust, topological property, but the charge currents are non-topological-and therefore sensitive to microscopic details-even if we neglect Meissner screening. We give insight into the non-topological nature of edge currents in chiral p-wave superconductors using a variety of theoretical techniques, including lattice Bogoliubov-de Gennes equations, the quasiclassical approximation, and the gradient expansion, and describe those special cases where edge currents do have a topological character. While edge currents are not quantized, they are generically large, but can be substantially reduced for a sufficiently anisotropic gap function, a scenario of possible relevance for the putative chiral p-wave superconductor Sr2RuO4 . Supported by NSERC and CIFAR at McMaster and by the Canada Research Chair and Canada Council Killam programs and NSF Grant No. NSF PHY11-25915 (CK). SL is supported by the DOE Office of Basic Energy Sciences, contract DEAC02-76SF00515 19. Applications of detailed 3D P-wave velocity crustal model in Poland for local, regional and global seismic tomography NASA Astrophysics Data System (ADS) Polkowski, Marcin; Grad, Marek 2015-04-01 The 3D P-wave seismic velocity model was obtained by combining data from multiple studies during past 50 years. Data sources included refraction seismology, reflection seismology, geological boreholes, vertical seismic profiling, magnetotellurics and gravimetry. Use of many data sources allowed creation of detailed 3D P-wave velocity model that reaches to depth of 60 km and includes 6-layers of sediments and 3-layers of the crust. Purpose of this study is to analyze how 3D model influences local (accuracy of location and source time estimation for local events), regional (identification of wide-angle seismic phases) and global (teleseismic tomography) seismic travel times. Additionally we compare results of forward seismic wave propagation with signals observed on short period and broadband stations. National Science Centre Poland provided financial support for this work by NCN grant DEC-2011/02/A/ST10/00284. 20. Crustal parameters estimated from P -waves of earthquakes recorded at a small array Microsoft Academic Search James N. Murdock; J. Alan Steppe 1980-01-01 TheP-arrival times of local and regional earthquakes that are outside of a small network of seismometers can be used to interpret crustal parameters beneath the network by employing the time-term technique. Even when the estimate of the refractor velocity is poorly determined, useful estimates of the station time-terms can be made. The method is applied to a 20 km diameter 1. Crustal parameters estimated from P-waves of earthquakes recorded at a small array Microsoft Academic Search James N. Murdock; J. Alan Steppe 1980-01-01 The P-arrival times of local and regional earthquakes that are outside of a small network of seismometers can be used to interpret crustal parameters beneath the network by employing the time-term technique. Even when the estimate of the refractor velocity is poorly determined, useful estimates of the station time-terms can be made. The method is applied to a 20 km 2. Simultaneous Determination of Average Thickness and P-wave Speed of the Crust by Virtual Deep Seismic Sounding (VDSS) NASA Astrophysics Data System (ADS) Kang, D.; Yu, C.; Ning, J.; TAO, K.; Chen, W. P. 2014-12-01 Using teleseismic S-waves, VDSS treats the SV-to-P conversion under the free surface (on the station-side) as a virtual source to generate strong, post-critical reflection off the Moho (SsPmp phase). With just a single, good-quality earthquake, arrival-time difference between SsPmp and the direct S-phase (TSsPmp-Ss) can effectively determine the crustal thickness (H) near the receiver. However, there is a strong trade-off between H and P-wave speed (Vp) in the crust. Here we extend VDSS to constrain both H and Vp by taking advantage of the variation in ray-parameters, or incident angles, as a function of epicentral distance. Note that in conventional receiver functions, information contained in data of different ray-parameters is usually lost, because stacking over move-out corrected data is required to get a clear signal. At a given station, we collect data from many events, each with a different ray-parameter of the direct S-phase (ps). For each event, we 1) estimate the source wavelet of the direct S-wave through particle motion analysis; 2) deconvolve this wavelet from the vertical- and radial-component seismograms (Yu et al., GJI, 2013); and then 3) determine TSsPmp-Ss through waveform modeling. Finally, we analyze data pairs (ps2, T2SsPmp-Ss) to find the best-fitting values of H and Vp. Synthetic tests verify the robustness of the method even with 15% of white noise. Moreover, we applied the method to public domain data from Forrest (FORT), located in the Eucla basin of western Australia. Based on 30 earthquakes from a narrow back-azimuth range (105±15°) but with ps changing from 0.1221 to 0.1349 s/km, we estimate that near FORT, H and Vp are about 44±2 km and 6.67±0.35 km/s, respectively. This crustal thickness is consistent with previous reports - a surprisingly high value for a region where the elevation is less than 200 m. Together with the high Vp, our results imply that the crust has a dense, mafic component. 3. Seismic Tomography of the Sacramento -- San Joaquin River Delta: Joint P-wave/Gravity and Ambient Noise Methods NASA Astrophysics Data System (ADS) Teel, Alexander C. The Sacramento -- San Joaquin River Delta (SSJRD) is an area that has been identified as having high seismic hazard but has resolution gaps in the seismic velocity models of the area due to a scarcity of local seismic stations and earthquakes. I present new three-dimensional (3D) P-wave velocity (Vp) and S-wave velocity (Vs) models for the SSJRD which fill in the sampling gaps of previous studies. I have created a new 3D seismic velocity model for the SSJRD, addressing an identified need for higher resolution velocity models in the region, using a new joint gravity/body-wave tomography algorithm. I am able to fit gravity and arrival-time residuals jointly using an empirical density-velocity relationship to take advantage of existing gravity data in the region to help fill in the resolution gaps of previous velocity models in the area. I find that the method enhances the ability to resolve the relief of basin structure relative to seismic-only tomography at this location. I find the depth to the basement to be the greatest in the northwest portion of the SSJRD and that there is a plateau in the basement structure beneath the southeast portion of the SSJRD. From my findings I infer that the SSJRD may be prone to focusing effects and basin amplification of ground motion. A 3D, Vs model for the SSJRD and surrounding area was created using ambient noise tomography. The empirical Green's functions are in good agreement with published cross-correlations and match earthquake waveforms sharing similar paths. The group velocity and shear velocity maps are in good agreement with published regional scale models. The new model maps velocity values on a local scale and successfully recovers the basin structure beneath the Delta. From this Vs model I find the maximum depth of the basin to reach approximately 15 km with the Great Valley Ophiolite body rising to a depth of 10 km east of the SSJRD. We consider our basement-depth estimates from the Vp model to be more robust than from the Vs model. 4. OSU CAREER FAIR INFORMATION PRE ARRIVAL ARRANGEMENTS E-print Network Escher, Christine registration fee. #12;ARRIVAL INFORMATION Location, Check-in and Unloading Materials The Career Fair is located on the north side of the CH2M Hill Alumni Center to unload and check in before you park. Parking permits and student parking areas. Booth Set Up You may unload your materials any time after 8:30 a.m. at the north 5. PRE-ARRIVAL HANDBOOK International Office E-print Network Petriu, Emil M. THAMMASAT UNIVERSITY PRE-ARRIVAL HANDBOOK International Office Student Visa Health & Insurance not recommend you to apply for a tourist visa to come to Thailand as a student unless there is a special to student. Then you have to renew after the end of period. This is rather costly and time consumption 6. An efficient hybrid pseudospectral/finite-difference scheme for solving the TTI pure P-wave equation NASA Astrophysics Data System (ADS) Zhan, Ge; Pestana, Reynam C.; Stoffa, Paul L. 2013-04-01 The pure P-wave equation for modelling and migration in tilted transversely isotropic (TTI) media has attracted more and more attention in imaging seismic data with anisotropy. The desirable feature is that it is absolutely free of shear-wave artefacts and the consequent alleviation of numerical instabilities generally suffered by some systems of coupled equations. However, due to several forward-backward Fourier transforms in wavefield updating at each time step, the computational cost is significant, and thereby hampers its prevalence. We propose to use a hybrid pseudospectral (PS) and finite-difference (FD) scheme to solve the pure P-wave equation. In the hybrid solution, most of the cost-consuming wavenumber terms in the equation are replaced by inexpensive FD operators, which in turn accelerates the computation and reduces the computational cost. To demonstrate the benefit in cost saving of the new scheme, 2D and 3D reverse-time migration (RTM) examples using the hybrid solution to the pure P-wave equation are carried out, and respective runtimes are listed and compared. Numerical results show that the hybrid strategy demands less computation time and is faster than using the PS method alone. Furthermore, this new TTI RTM algorithm with the hybrid method is computationally less expensive than that with the FD solution to conventional TTI coupled equations. 7. Arrival Map and Unloading Directions E-print Network Royer, Dana Arrival Map and Unloading Directions Arrival Day Instructions If you live in Butterfield A or B at the Exley Science Center before unloading. If you live in Clark Hall, Butterfield C, 200 Church Street, Fauver, or 156 High Street, check in and unload at your residential area, park in one of the des- ignated 8. Calibration of the bunched exponential distribution of arrival headways Microsoft Academic Search Rahmi Akçelik; Edward Chung The estimation of arrival headways is fundamental to the modelling of gap acceptance processes for estimating capacities of sign-controlled traffic streams, roundabout entry streams and filter turns at signalised intersections. It is also essential in modelling both vehicle-actuated signal timings and queuing at all types of intersections for performance prediction. This paper considers a class of arrival headway distributions known 9. Signal processing and tracking of arrivals in ocean acoustic tomography. PubMed Dzieciuch, Matthew A 2014-11-01 The signal processing for ocean acoustic tomography experiments has been improved to account for the scattering of the individual arrivals. The scattering reduces signal coherence over time, bandwidth, and space. In the typical experiment, scattering is caused by the random internal-wave field and results in pulse spreading (over arrival-time and arrival-angle) and wander. The estimator-correlator is an effective procedure that improves the signal-to-noise ratio of travel-time estimates and also provides an estimate of signal coherence. The estimator-correlator smoothes the arrival pulse at the expense of resolution. After an arrival pulse has been measured, it must be associated with a model arrival, typically a ray arrival. For experiments with thousands of transmissions, this is a tedious task that is error-prone when done manually. An error metric that accounts for peak amplitude as well as travel-time and arrival-angle can be defined. The Viterbi algorithm can then be adapted to the task of automated peak tracking. Repeatable, consistent results are produced that are superior to a manual tracking procedure. The tracking can be adjusted by tuning the error metric in logical, quantifiable manner. PMID:25373953 10. The correlations between the saturated and dry P-wave velocity of rocks. PubMed Kahraman, S 2007-11-01 Sometimes engineers need to estimate the wet-rock P-wave velocity from the dry-rock P-wave velocity. An estimation equation embracing all rock classes will be useful for the rock engineers. To investigate the predictability of wet-rock P-wave velocity from the dry-rock P-wave velocity, P-wave velocity measurements were performed on 41 different rock types, 11 of which were igneous, 15 of which were sedimentary and 15 of which was metamorphic. In addition to the dry- and wet-rock P-wave velocity measurements, the P-wave velocity changing as a function of saturation degree was studied. Moreover, dry-rock S-wave velocity measurements were conducted. The test results were modeled using Gassmann's and Wood's theory and it was seen that the measured data did not fit the theories. The unconformity is due to the fact that the theories are valid for high-porosity unconsolidated sediments at low frequencies. Gassmann's equation was modified for the rocks except high-porosity unconsolidated sediments. The dry- and wet-rock P-wave velocity values were evaluated using regression analysis. A strong linear correlation between the dry- and wet-rock P-wave velocities was found. Regression analyses were repeated for the rock classes and it was shown that correlation coefficients were increased. Concluding remark is that the derived equations can be used for the prediction of wet-rock P-wave velocity from the dry-rock P-wave velocity. PMID:17624388 11. P-wave velocity anomalies of the plume beneath the French Polynesia NASA Astrophysics Data System (ADS) Obayashi, Masayuki; Yoshimitsu, Junko; Sugioka, Hiroko; Ito, Aki; Isse, Takehi; Shiobara, Hajime; Suetsugu, Daisuke 2015-04-01 The French Polynesian region is characterized by positive topographic anomalies of 700 m, a concentration of hotspot chains. Many seismic tomography results show a broad low-velocity anomaly in the lower mantle continued from the base of the mantle. These observations suggest that a large-scale mantle flow rises from the bottom of the mantle beneath the region. Joint Japanese-French broadband seismological observations were performed from 2001 to 2005 with 10 island stations from the Polynesian PLUME project (Barruol et al. 2002) and 10 broadband ocean bottom seismometers (BBOBSs) from the Polynesian BBOBS project (Suetsugu et al. 2005). A P-wave tomography using the data from these projects revealed that large-scale low-velocity anomalies (on the order of 1000 km in diameter) from the bottom of the mantle become smaller-scale low-velocity anomalies (on the order of 100 km in diameter) at the depth of about 1000 km. However the connection of the small-scale low-velocity anomalies to the surface hotspots was not unrevealed because of the poor resolution in the upper mantle. A new P-wave tomography with better resolution in the upper mantle was obtained by adding data from BBOSBSs around Society Islands deployed along the TIARES project during 2009 - 2010 (Suetsugu et al. 2012) and by taking the finite frequency effect into account for the frequency-depended differential travel times. The frequency-depended differential travel times were measured by multi-band cross correlating P waveforms. The new P-wave tomography shows strong low-velocity anomalies beneath the Society Islands and Pitcairn in the upper mantle although they do not extend to the 660-km discontinuity. This model also shows that small-scale low-velocity anomalies in the uppermost lower mantle. The low-velocity anomalies in the depth range about 550 - 900 km are smaller both in lateral area and amplitude than those in most of the upper mantle and the lower mantle. The velocity patterns are well correlated each other in the depth range but are not correlated with the patterns above and below, indicating the mantle beneath the French polynesia can be divided into 3 layers in terns of radial correlation. 12. Converted-wave PS arrivals in tilted TI media: Analysis of ray-paths and amplitudes NASA Astrophysics Data System (ADS) Ramos-Martinez, J.; Calderon-Macias, C. 2005-05-01 Converted-waves, i.e., downgoing P-waves that convert upon reflection to S-waves, excited by a compressional source and recorded by horizontal geophones provide a measure of media properties that relate to rock type and fluid saturation. Other uses that have arisen from measuring, analyzing and interpreting PS-waves, include improved structural imaging in formations with occurrence of gas and analysis of seismic anisotropy for estimating fracture density and orientation. Addressing anisotropy in the seismic processing flow is paramount due to the strong influence of this phenomenon in the wave path. Furthermore, analyses of both traveltimes and amplitudes that include anisotropic parameters provide a better picture of the subsurface. Anisotropy types used to describe common geologic scenarios include vertical and horizontal transversely isotropy (VTI and HTI, respectively). Presence of horizontal shale formations is a common cause of the VTI type, while a single vertical fracture system is a typical example of the HTI. Another degree of complexity is to consider a tilted symmetry axis corresponding to a formation with thin layers that are dipping, or the presence of non-vertical fractures. These media, described as tilted TI, have important observable effects on the converted-wave arrivals: i) asymmetry of the wave-path; ii) shear-wave splitting; and iii) non-zero amplitudes at zero offset. Based on numerical modeling, effects of the tilt in the simmetry axis on arrival times, travel path, and amplitudes of the converted waves are analyzed. Ultimate objectives of the work include quantifying these effects on converted-wave data processing, and investigating the reflected wavefield signature for retrieving tilt angle in situations where the stress field induces thin layering or fractures with a tilted symmetry axis. 13. P -wave charmed baryons from QCD sum rules NASA Astrophysics Data System (ADS) Chen, Hua-Xing; Chen, Wei; Mao, Qiang; Hosaka, Atsushi; Liu, Xiang; Zhu, Shi-Lin 2015-03-01 We study the P -wave charmed baryons using the method of QCD sum rule in the framework of heavy quark effective theory. We consider systematically all possible baryon currents with a derivative for internal ? - and ? -mode excitations. We have found a good working window for the currents corresponding to the ? -mode excitations for ?c(2595 ), ?c(2625 ), ?c(2790 ), and ?c(2815 ) that complete two S U (3 ) 3¯F multiplets of JP=1 /2- and 3 /2-, while the currents corresponding to the ? -mode excitations seem also consistent with the data. Our results also suggest that there are two ?c(2800 ) states of JP=1 /2- and 3 /2- whose mass splitting is 14 ±7 MeV , and two ?c(2980 ) states whose mass splitting is 12 ±7 MeV . They have two ?c partners of JP=1 /2- and 3 /2-, whose masses are around 3.25 ±0.20 GeV with mass splitting 10 ±6 MeV . All of them together complete two S U (3 ) 6F multiplets of JP=1 /2- and 3 /2-. They may also have JP=5 /2- partners. ?c(3080 ) may be one of them, and the other two are ?c(5 /2-) and ?c(5 /2-), whose masses are 85 ±23 MeV and 50 ±27 MeV larger. 14. Magnetic-field effects on p-wave phase transition in Gauss-Bonnet gravity NASA Astrophysics Data System (ADS) Wu, Ya-Bo; Lu, Jun-Wang; Jin, Yong-Yi; Lu, Jian-Bo; Zhang, Xue; Wu, Si-Yu; Wang, Cui 2014-07-01 In the probe limit, we study the holographic p-wave phase transition in the Gauss-Bonnet gravity via numerical and analytical methods. Concretely, we study the influences of the external magnetic field on the Maxwell complex vector model in the five-dimensional Gauss-Bonnet-AdS black hole and soliton backgrounds, respectively. For the two backgrounds, the results show that the magnetic field enhances the superconductor phase transition in the case of the lowest Landau level, while the increasing Gauss-Bonnet parameter always hinders the vector condensate. Moreover, the Maxwell complex vector model is a generalization of the SU(2) Yang-Mills model all the time. In addition, the analytical results backup the numerical results. Furthermore, this model might provide a holographic realization for the QCD vacuum instability. 15. Magnitude determination using initial P waves: A single-station Yih-Min Wu,1 E-print Network Wu, Yih-Min Magnitude determination using initial P waves: A single-station approach Yih-Min Wu,1 Hsin-Yi Yen,1 the magnitudes of earthquakes and the properties of the first three seconds of the P waves at a single station within 100-km epicentral distance, we found a linear correlation between the magnitudes 16. Upper mantle Q and thermal structure beneath Tanzania, East Africa from teleseismic P wave spectra Microsoft Academic Search Anupama Venkataraman; Andrew A. Nyblade; Jeroen Ritsema 2004-01-01 We measure P wave spectral amplitude ratios from deep-focus earthquakes recorded at broadband seismic stations of the Tanzania network to estimate regional variation of sublithospheric mantle attenuation beneath the Tanzania craton and the eastern branch of the East African Rift. One-dimensional profiles of QP adequately explain the systematic variation of P wave attenuation in the sublithospheric upper mantle: QP ~ 17. Upper mantle Q and thermal structure beneath Tanzania, East Africa from teleseismic P wave spectra Microsoft Academic Search Anupama Venkataraman; Andrew A. Nyblade; Jeroen Ritsema 2004-01-01 We measure P wave spectral amplitude ratios from deep-focus earthquakes recorded at broadband seismic stations of the Tanzania network to estimate regional variation of sublithospheric mantle attenuation beneath the Tanzania craton and the eastern branch of the East African Rift. One-dimensional profiles of QP adequately explain the systematic variation of P wave attenuation in the sublithospheric upper mantle: QP ? 18. EFFECT OF IMMISCIBLE LIQUID CONTAMINANTS ON P-WAVE TRANSMISSION THROUGH NATURAL AQUIFER SAMPLES E-print Network Ajo-Franklin, Jonathan EFFECT OF IMMISCIBLE LIQUID CONTAMINANTS ON P-WAVE TRANSMISSION THROUGH NATURAL AQUIFER SAMPLES Jil the effect of non-aqueous phase liquid (NAPL) contaminants on P-wave velocity and attenuation contamination in the surficial aquifer. Field measurements revealed a zone of anomalously high seismic 19. P wave dispersion is prolonged in patients with Wilson’s disease Microsoft Academic Search Nurcan Arat; Sabite Kacar; Zehra Golbasi; Meral Akdogan; Yeliz Sokmen; Sedef Kuran; Ramazan Idilman; Türkiye Yüksek 2008-01-01 AIM: To investigate the P wave dispersion as a non- invasive marker of intra-atrial conduction disturbances in patients with Wilson's disease. METHODS: We compared Wilson's disease patients (n = 18) with age matched healthy subjects (n = 15) as controls. The diagnosis was based on clinical symptoms, laboratory tests (ceruloplasmin, urinary and hepatic copper concentrations). P wave dispersion, a measurement 20. Inferences on Crustal Velocities and Densities from P Wave Delays and Gravity Anomalies Microsoft Academic Search SHAWN BIEI-ILER 1964-01-01 A correlation is demonstrated between P wave delays and Bouguer gravity anomalies. For California data it is given approximately by (Ag> _-- --355PD where (Ag> is the Bouguer (slab equivalent) gravity change in milligals and PD is the delay in seconds. The increases in P wave delays and negative gravity anomalies associated with topographic highs are manifestations of isostatic adjustment. 1. Knowledge-based scheduling of arrival aircraft NASA Technical Reports Server (NTRS) Krzeczowski, K.; Davis, T.; Erzberger, H.; Lev-Ram, I.; Bergh, C. 1995-01-01 A knowledge-based method for scheduling arrival aircraft in the terminal area has been implemented and tested in real-time simulation. The scheduling system automatically sequences, assigns landing times, and assigns runways to arrival aircraft by utilizing continuous updates of aircraft radar data and controller inputs. The scheduling algorithms is driven by a knowledge base which was obtained in over two thousand hours of controller-in-the-loop real-time simulation. The knowledge base contains a series of hierarchical 'rules' and decision logic that examines both performance criteria, such as delay reduction, as well as workload reduction criteria, such as conflict avoidance. The objective of the algorithms is to devise an efficient plan to land the aircraft in a manner acceptable to the air traffic controllers. This paper will describe the scheduling algorithms, give examples of their use, and present data regarding their potential benefits to the air traffic system. 2. Finite-fault source inversion using teleseismic P waves: simple parameterization and rapid analysis USGS Publications Warehouse Mendoza, C.; Hartzell, S. 2013-01-01 We examine the ability of teleseismic P waves to provide a timely image of the rupture history for large earthquakes using a simple, 2D finite?fault source parameterization. We analyze the broadband displacement waveforms recorded for the 2010 Mw~7 Darfield (New Zealand) and El Mayor?Cucapah (Baja California) earthquakes using a single planar fault with a fixed rake. Both of these earthquakes were observed to have complicated fault geometries following detailed source studies conducted by other investigators using various data types. Our kinematic, finite?fault analysis of the events yields rupture models that similarly identify the principal areas of large coseismic slip along the fault. The results also indicate that the amount of stabilization required to spatially smooth the slip across the fault and minimize the seismic moment is related to the amplitudes of the observed P waveforms and can be estimated from the absolute values of the elements of the coefficient matrix. This empirical relationship persists for earthquakes of different magnitudes and is consistent with the stabilization constraint obtained from the L?curve in Tikhonov regularization. We use the relation to estimate the smoothing parameters for the 2011 Mw 7.1 East Turkey, 2012 Mw 8.6 Northern Sumatra, and 2011 Mw 9.0 Tohoku, Japan, earthquakes and invert the teleseismic P waves in a single step to recover timely, preliminary slip models that identify the principal source features observed in finite?fault solutions obtained by the U.S. Geological Survey National Earthquake Information Center (USGS/NEIC) from the analysis of body? and surface?wave data. These results indicate that smoothing constraints can be estimated a priori to derive a preliminary, first?order image of the coseismic slip using teleseismic records. 3. [A new approach to wavelet-based P-wave detection]. PubMed Wan, Xiangkui; Qin, Shuren; Liang, Xiaorong; Ding, Jianping 2006-08-01 According to the characteristics of four basic P morphologies, combining the wavelet transform and the amplitude and slope of transformed P wave, a new P-wave detecting method based on "wavelet-amplitude-slope" algorithm is presented: First search out all modulus maximum pairs to satisfy the threshold after wavelet transform, and then applying the amplitude and slope criterion exclude the interferes and detect the P peak and its shape, last determine the onset and end of P wave respectively which should be separately calculated for single-peak and double-peak P wave (or biphasic P wave). The approach is applied in experiments of data from MIT/BIH database and randomly collected data of clinical ECG. The experimental statistical results shows that the correct detecting rate is as high as 96% compared to manual annotation. PMID:17002093 4. Pseudo 3-D P wave refraction seismic monitoring of permafrost in steep unstable bedrock NASA Astrophysics Data System (ADS) Krautblatter, Michael; Draebing, Daniel 2014-02-01 permafrost in steep rock walls can cause hazardous rock creep and rock slope failure. Spatial and temporal patterns of permafrost degradation that operate at the scale of instability are complex and poorly understood. For the first time, we used P wave seismic refraction tomography (SRT) to monitor the degradation of permafrost in steep rock walls. A 2.5-D survey with five 80 m long parallel transects was installed across an unstable steep NE-SW facing crestline in the Matter Valley, Switzerland. P wave velocity was calibrated in the laboratory for water-saturated low-porosity paragneiss samples between 20°C and -5°C and increases significantly along and perpendicular to the cleavage by 0.55-0.66 km/s (10-13%) and 2.4-2.7 km/s (>100%), respectively, when freezing. Seismic refraction is, thus, technically feasible to detect permafrost in low-porosity rocks that constitute steep rock walls. Ray densities up to 100 and more delimit the boundary between unfrozen and frozen bedrock and facilitate accurate active layer positioning. SRT shows monthly (August and September 2006) and annual active layer dynamics (August 2006 and 2007) and reveals a contiguous permafrost body below the NE face with annual changes of active layer depth from 2 to 10 m. Large ice-filled fractures, lateral onfreezing of glacierets, and a persistent snow cornice cause previously unreported permafrost patterns close to the surface and along the crestline which correspond to active seasonal rock displacements up to several mm/a. SRT provides a geometrically highly resolved subsurface monitoring of active layer dynamics in steep permafrost rocks at the scale of instability. 5. Model input and output files for the simulation of time of arrival of landfill leachate at the water table, Municipal Solid Waste Landfill Facility, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas USGS Publications Warehouse Abeyta, Cynthia G.; Frenzel, Peter F. 1999-01-01 This report contains listings of model input and output files for the simulation of the time of arrival of landfill leachate at the water table from the Municipal Solid Waste Landfill Facility (MSWLF), about 10 miles northeast of downtown El Paso, Texas. This simulation was done by the U.S. Geological Survey in cooperation with the U.S. Department of the Army, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso, Texas. The U.S. Environmental Protection Agency-developed Hydrologic Evaluation of Landfill Performance (HELP) and Multimedia Exposure Assessment (MULTIMED) computer models were used to simulate the production of leachate by a landfill and transport of landfill leachate to the water table. Model input data files used with and output files generated by the HELP and MULTIMED models are provided in ASCII format on a 3.5-inch 1.44-megabyte IBM-PC compatible floppy disk. 6. Project SMART 2013 -Frequently asked questions The remaining payment can be made any time before arrival by check. It is$3200 if you do not
E-print Network
Pringle, James "Jamie"
Project SMART 2013 - Frequently asked questions The remaining payment can be made any time before schedule? Is there daily homework? DEPENDS ON THE MODULE - FULL DAY OF SCHEDULE - NO REAL HOME WORK mail from home while they are @ UNH? YES SEE HOUSING INFO - TYPICALLY THEY COMMUNICATE BY CELL PHONE
7. Complex seismic amplitude inversion for P-wave and S-wave quality factors
Zong, Zhaoyun; Yin, Xingyao; Wu, Guochen
2015-07-01
Stratum quality factors (P-wave and S-wave quality factors, Qp and Qs) have gradually been utilized in the study of physical state of crust and uppermost mantle, tectonic evolution, hydrogeololgy, gas hydrates, petroleum exploration, etc. Different opinions of the seismic attenuation mechanism result in various approaches to estimate the P-wave and S-wave quality factors. Considering the viscoelasticity of the underground medium, the constitutive matrix of the Earth medium is written as the superposition of homogeneous background medium, elastic perturbation medium and viscoelastic perturbation medium. Under the hypothesis of Born integral and stationary phase approximation, the seismic reflectivity is initially raised in terms of P-wave and S-wave moduli, density, P-wave and S-wave quality factors. Furthermore, incorporating the complex seismic traces with the seismic wavelets at different offsets, a two-step inversion approach is proposed to estimate the P-wave and S-wave quality factors. The AVO/AVA Bayesian inversion approach is suggested to estimate the P-wave modulus and S-wave modulus with the real component of the pre-stack seismic data initially. Taking the estimated P-wave and S-wave moduli as prior information, the P-wave and S-wave quality factors are further estimated with the imaginary component of the complex pre-stack seismic data, which is the quadrature of the original data. Finally, synthetic examples demonstrate that the proposed approach is able to estimate P-wave and S-wave quality factors stably and properly, and two field data examples demonstrate that the proposed approach may work as an efficient approach to fluid identification.
8. Electric car arrives - again
SciTech Connect
Dunn, S.
1997-03-01
The first mass-produced electric cars in modern times are here, although they are expensive, limited in capability and unfamiliar to most prospective consumers. This article presents a brief history of the reintroduction of the modern electric car as well as discussions of the limitations of development, alternative routes to both producing and selling electric cars or some modified version of electric cars, economic incentives and governmental policies, and finally a snapshot description of the future for electric cars. 6 refs., 1 tab.
9. hal-00166351,version2-1Apr2008 Three fully polarized fermions close to a p-wave Feshbach resonance
E-print Network
Boyer, Edmond
hal-00166351,version2-1Apr2008 Three fully polarized fermions close to a p-wave Feshbach resonance a resonant interaction in the p-wave channel via a Feshbach resonance represented by a two-channel model superfluidity with p-wave pairing is related to a large class of subjects in very different areas of physics
10. Spin density wave fluctuations and p-wave pairing in Sr2RuO4.
PubMed
Huo, Jia-Wei; Rice, T M; Zhang, Fu-Chun
2013-04-19
Recently, a debate has arisen over which of the two distinct parts of the Fermi surface of Sr(2)RuO(4) is the active part for the chiral p-wave superconductivity exhibited. Early theories proposed p-wave pairing on the two-dimensional ? band, whereas a recent proposal focuses on the one-dimensional (?, ?) bands whose nesting pockets are the source of the strong incommensurate spin density wave (SDW) fluctuations. We apply a renormalization group theory to study quasi-one-dimensional repulsive Hubbard chains and explain the form of SDW fluctuations, reconciling the absence of long-range order with their nesting Fermi surface. The mutual exclusion of p-wave pairing and SDW fluctuations in repulsive Hubbard chains favors the assignment of the two-dimensional ? band as the source of p-wave pairing. PMID:23679633
11. A black hole window into p-wave dark matter annihilation
E-print Network
Jessie Shelton; Stuart L. Shapiro; Brian D. Fields
2015-06-12
We present a new method to measure or constrain p-wave-suppressed cross sections for dark matter (DM) annihilations inside the steep density spikes induced by supermassive black holes. We demonstrate that the high DM densities, together with the increased velocity dispersion, within such spikes combine to make thermal p-wave annihilation cross-sections potentially visible in gamma-ray observations of the Galactic center (GC). The resulting DM signal is a bright central point source with emission originating from DM annihilations in the absence of a detectable spatially-extended signal from the halo. We define two simple reference theories of DM with a thermal p-wave annihilation cross-section and establish new limits on the combined particle and astrophysical parameter space of these models, demonstrating that Fermi is currently sensitive to thermal p-wave DM over a wide range of possible scenarios for the DM distribution in the GC.
12. A black hole window into p-wave dark matter annihilation
E-print Network
Shelton, Jessie; Fields, Brian D
2015-01-01
We present a new method to measure or constrain p-wave-suppressed cross sections for dark matter (DM) annihilations inside the steep density spikes induced by supermassive black holes. We demonstrate that the high DM densities, together with the increased velocity dispersion, within such spikes combine to make thermal p-wave annihilation cross-sections potentially visible in gamma-ray observations of the Galactic center (GC). The resulting DM signal is a bright central point source with emission originating from DM annihilations in the absence of a detectable spatially-extended signal from the halo. We define two simple reference theories of DM with a thermal p-wave annihilation cross-section and establish new limits on the combined particle and astrophysical parameter space of these models, demonstrating that Fermi is currently sensitive to thermal p-wave DM over a wide range of possible scenarios for the DM distribution in the GC.
13. Mariscope: Observing P Waves (and much more) Everywhere in the Oceans
Nolet, G.; Hello, Y.; Bonnieux, S.; Sukhovich, A.; Simons, F. J.
2014-12-01
The lack of stations on islands or the ocean bottom deprives seismic tomographers of almost 2/3 of the information potentially available for global seismic tomography. The "Mermaid", developed at Geoazur, is an underwater seismograph, based on a TWR Apex float. P wave signals are automatically identified and transmitted using the detection algorithm from Sukhovich et al. (GRL, 2011), GPS is used to locate the sensor at the time of transmission. We have studied the performance of Mermaids under different noise conditions in the Mediterranean, Indian Ocean and most recently near the Galapagos islands and will show a selection of observations. In the Mediterranean, we regularly detect P waves at teleseismic distances of earthquakes with magnitude 6, occasionally below that. Local and regional earthquakes of much lower magnitude, such as a M 4.9 earthquake near Barcelonette (figure), yield seismograms with a high signal to noise ratio.In the much noisier environment of the Indian Ocean the threshold for useful seismograms is close to magnitude 6.5. Yet we were also able to record 235 low magnitude events when a Mermaid was close to a swarm near the Indian Ocean triple junction, with the lowest magnitude estimated to be 2.1; this sequence also enabled us to put an upper limit of about 250 m to the error in sensor location at the time of recording. Preliminary data from the Galapagos indicate low noise conditions similar to those in the Mediterranean, with good recordings of events in the magnitude 5 range.A new prototype of a spherical "MultiMermaid" is currently being tested. It allows for multidisciplinary observations (seismic and kHz acoustics, magnetic field, temperature, bathymetry) and will function about five years with lithium batteries. A global deployment of such instruments in a five-year program is affordable: project MariScope aims for at least 300 floating seismometers in the world's oceans. At the time of writing of this abstract, a proposal is being prepared that involves geophysicists and biologists from France, Germany, Italy and Greece and should result in a first installment of MariScope. We shall discuss the possibility of a local rapid response network in which the instruments locate themselves while under water.
14. A Powerful Twin Arrives
1999-11-01
First Images from FORS2 at VLT KUEYEN on Paranal The first, major astronomical instrument to be installed at the ESO Very Large Telescope (VLT) was FORS1 ( FO cal R educer and S pectrograph) in September 1998. Immediately after being attached to the Cassegrain focus of the first 8.2-m Unit Telescope, ANTU , it produced a series of spectacular images, cf. ESO PR 14/98. Many important observations have since been made with this outstanding facility. Now FORS2 , its powerful twin, has been installed at the second VLT Unit Telescope, KUEYEN . It is the fourth major instrument at the VLT after FORS1 , ISAAC and UVES.. The FORS2 Commissioning Team that is busy installing and testing this large and complex instrument reports that "First Light" was successfully achieved already on October 29, 1999, only two days after FORS2 was first mounted at the Cassegrain focus. Since then, various observation modes have been carefully tested, including normal and high-resolution imaging, echelle and multi-object spectroscopy, as well as fast photometry with millisecond time resolution. A number of fine images were obtained during this work, some of which are made available with the present Press Release. The FORS instruments ESO PR Photo 40a/99 ESO PR Photo 40a/99 [Preview - JPEG: 400 x 345 pix - 203k] [Normal - JPEG: 800 x 689 pix - 563kb] [Full-Res - JPEG: 1280 x 1103 pix - 666kb] Caption to PR Photo 40a/99: This digital photo shows the twin instruments, FORS2 at KUEYEN (in the foreground) and FORS1 at ANTU, seen in the background through the open ventilation doors in the two telescope enclosures. Although they look alike, the two instruments have specific functions, as described in the text. FORS1 and FORS2 are the products of one of the most thorough and advanced technological studies ever made of a ground-based astronomical instrument. They have been specifically designed to investigate the faintest and most remote objects in the universe. They are "multi-mode instruments" that may be used in several different observation modes. FORS2 is largely identical to FORS1 , but there are a number of important differences. For example, it contains a Mask Exchange Unit (MXU) for laser-cut star-plates [1] that may be inserted at the focus, allowing a large number of spectra of different objects, in practice up to about 70, to be taken simultaneously. Highly sophisticated software assigns slits to individual objects in an optimal way, ensuring a great degree of observing efficiency. Instead of the polarimetry optics found in FORS1 , FORS2 has new grisms that allow the use of higher spectral resolutions. The FORS project was carried out under ESO contract by a consortium of three German astronomical institutes, the Heidelberg State Observatory and the University Observatories of Göttingen and Munich. The participating institutes have invested a total of about 180 man-years of work in this unique programme. The photos below demonstrate some of the impressive possibilities with this new instrument. They are based on observations with the FORS2 standard resolution collimator (field size 6.8 x 6.8 armin = 2048 x 2048 pixels; 1 pixel = 0.20 arcsec). In addition, observations of the Crab pulsar demonstrate a new observing mode, high-speed photometry. Protostar HH-34 in Orion ESO PR Photo 40b/99 ESO PR Photo 40b/99 [Preview - JPEG: 400 x 444 pix - 220kb] [Normal - JPEG: 800 x 887 pix - 806kb] [Full-Res - JPEG: 2000 x 2217 pix - 3.6Mb] The Area around HH-34 in Orion ESO PR Photo 40c/99 ESO PR Photo 40c/99 [Preview - JPEG: 400 x 494 pix - 262kb] [Full-Res - JPEG: 802 x 991 pix - 760 kb] The HH-34 Superjet in Orion (centre) PR Photo 40b/99 shows a three-colour composite of the young object Herbig-Haro 34 (HH-34) , now in the protostar stage of evolution. It is based on CCD frames obtained with the FORS2 instrument in imaging mode, on November 2 and 6, 1999. This object has a remarkable, very complicated appearance that includes two opposite jets that ram into the surrounding interstellar matter. This structure is produced by a machine-gu
15. Tuning p-wave interactions in an ultracold Fermi gas of atoms.
PubMed
Regal, C A; Ticknor, C; Bohn, J L; Jin, D S
2003-02-01
We have measured a p-wave Feshbach resonance in a single-component, ultracold Fermi gas of 40K atoms. We have used this resonance to enhance the normally suppressed p-wave collision cross section to values larger than the background s-wave cross section between 40K atoms in different spin states. In addition to the modification of two-body elastic processes, the resonance dramatically enhances three-body inelastic collisional loss. PMID:12633351
16. P wave anisotropy, stress, and crack distribution at Coso geothermal field, California
Jonathan M. Lees; Huatao Wu
1999-01-01
A new inversion method for P wave anisotropy [Wu and Lees, 1999a] has been applied to high-precision, microseismic traveltime data collected at Coso geothermal region, California. Direction-dependent P wave velocity and thus its perturbation, are represented by a symmetric positive definite matrix A instead of a scalar. The resulting anisotropy distribution is used to estimate variations in crack density, stress
17. Local Determination of Weak Anisotropy Parameters from qP -wave Slowness and Particle Motion Measurements
XUYAO ZHENG; I. Pšen?ík
2002-01-01
-- We propose an algorithm for local evaluation of weak anisotropy (WA) parameters from measurements of slowness vector components and\\/or of particle motions of qP waves at individual receivers in a borehole in a multi-azimuthal multiple-source offset VSP experiment. As a byproduct the algorithm yields approximate angular variation of qP-wave phase velocity. The formulae are derived under assumption of weak
18. Collaborative Arrival Planning: Data Sharing and User Preference Tools
NASA Technical Reports Server (NTRS)
Zelenka, Richard E.; Edwards, Thomas A. (Technical Monitor)
1998-01-01
Air traffic growth and air carrier economic pressures have motivated efforts to increase the flexibility of the air traffic management process and change the relationship between the air traffic control service provider and the system user. One of the most visible of these efforts is the U.S. government/industry "free flight" initiative, in which the service provider concentrates on safety and cross-airline fairness, and the user on their business objectives and operating preferences, including selecting their own path and speed in real-time. In the terminal arrival phase of flight, severe restrictions and rigid control are currently placed on system users, typically without regard for individual user operational preferences. Airborne delays applied to arriving aircraft into capacity constrained airports are imposed on a first-come, first-serve basis, and thus do not allow the system user to plan for or prioritize late arrivals, or to economically optimize their arrival sequence. A central tenant of the free-flight operating paradigm is collaboration between service providers and users in reaching air traffic management decisions. Such collaboration would be particularly beneficial to an airline's "hub" operation, where off-schedule arrival aircraft are a consistent problem, as they cause serious air-port ramp difficulties, rippling airline scheduling effects, and result in large economic inefficiencies. Greater collaboration can also lead to increased airport capacity and decrease the severity of over-capacity rush periods. In the NASA Collaborative Arrival Planning (CAP) project, both independent exchange of real-time data between the service provider and system user and collaborative decision support tools are addressed. Data exchange of real-time arrival scheduling, airspace management, and air carrier fleet data between the FAA service provider and an air carrier is being conducted and evaluated. Collaborative arrival decision support tools to allow intra-airline arrival preferences are being developed and simulated. The CAP project is part of and leveraged from the NASA/FAA Center TRACON Automation System (CTAS), a fielded set of decision support tools that provide computer generated advisories for both enroute and terminal area controllers to manage and control arrival traffic more efficiently. In this paper, the NASA Collaborative Arrival Planning project is outlined and recent results detailed, including the real-time use of CTAS arrival scheduling data by a major air carrier and simulations of tactical and strategic user preference decision support tools.
19. Murray Edwards Arriving by Road
E-print Network
Goldschmidt, Christina
Murray Edwards College Arriving by Road To reach the Storey's Way car park using sat-nav, enter the postcode CB3 0DR/number 61. Please note that due to road-narrowing bollards, Storey's Way is a no-through road for wide vehicles/coaches. Murray Edwards College is situated on Huntingdon Road, 1 mile west
20. Location: From To Depart Arrive
E-print Network
Arizona, University of
. A credit card slip is not a valid receipt by itself. Phone calls on hotel bill must be business (academicDate: Email: Phone: Location: From To Depart Arrive A B C Amount D DATE: I HEREBY CERTIFY THAT I AM in the conference registration you may not claim Per Diem for that meal. Get baggage handling and taxi receipts. Any
1. THE OBSERVABILITY OF MULTIPLY REFLECTED P WAVES Michel Foundotos, Guust Nolet Geosciences Azur, University of Nice Sophia Antipolis, France
Foundotos, M.; Nolet, G.
2009-12-01
In order to constrain the shallow structure of the Earth in global tomography, Love and Rayleigh waves are often used. However these waves are mostly sensitive to the S wave velocity structure. P-wave energy is either evanescent, or leaking away at every surface reflection that generates an S wave which travels much deeper into the mantle. For that reason, to study the shallow P velocity structure of the Earth, we need to study P-waves at regional distances if a good seismic station coverage is available. Otherwise we can use multiple P reflections at teleseismic distance when regional data are not available (as in the oceans for instance). The major aim of this work was first of all to ensure that these multiply reflected P waves can adequately be observed in real data and also to investigate how many reflections at the surface these reflected waves can still be seen and to investigate how strongly the amplitude of multiply reflected P diminishes because of energy loss into S waves. For this study we are comparing the synthetic predictions computed with a Spectral Element Method for a spherically symmetric earth (Nissen-Meyer et al, 2007) with observed data. We used 150 events recorded (26575 seismograms) from the dense network of US ARRAY, which allows us to make a very large number of observations. Our study shows that three times reflected PPP waves are very well observed for epicentral distances > 60 degrees and for events with Mw<6.0, despite the ray-theoretical prediction that at certain distances almost all of their compressional energy is converted to shear waves. However, the four times reflected PPPP waves do not appear everywhere clearly. PPPP can be observed for epicentral distances > 90 degrees.
2. Body surface mapping of atrial arrhythmias: atlas of paced P wave integral maps to localize the focal origin of right atrial tachycardia.
PubMed
SippensGroenewegen, A; Roithinger, F X; Peeters, H A; Linnenbank, A C; van Hemel, N M; Steiner, P R; Lesh, M D
1998-01-01
Successful curative treatment of right atrial tachycardia (AT) can be obtained provided detailed catheter activation mapping of the target site for radiofrequency energy application has been accomplished. However, right AT mapping may be difficult with a single roving catheter due to infrequent presence or noninducibility of the arrhythmia. The present report describes the preliminary clinical use of body surface mapping as an adjunctive noninvasive method to identify the region of AT origin prior to catheter ablation. This technique has been previously applied to develop a reference data base of 17 different paced P wave integral map patterns. The data base was designed by performing right atrial pace mapping in patients without structural heart disease. Each P wave integral map pattern in the data base is unique to ectopic activation onset in a circumscribed right atrial endocardial segment. Localization of the segment of AT origin is accomplished by matching the P wave integral map of a single AT beat with the data base of paced P wave integral maps. The use of body surface mapping as an integral part of the mapping protocol during radiofrequency catheter ablation of right AT offers the possibility to: (1) noninvasively determine the arrhythmogenic target area for ablation using a single beat analysis approach; (2) confine detailed catheter activation mapping to a limited area; and (3) accelerate the overall procedure and limit fluoroscopic exposure by reducing the time required for mapping. PMID:9988010
3. Terminal area arrival management concepts using tactical merge management techniques
Aslaug Haraldsdottir; Janet King; Julien Scharl
2010-01-01
This paper describes operational concept options for 4D trajectory-based arrival management in the terminal area, using Flight Management Systems (FMS) capable of Area Navigation (RNAV), Required Navigation Performance (RNP), Vertical Navigation (VNAV), as well as Required Time of Arrival (RTA) and airplane-based Interval Management (IM). Furthermore, it is assumed that the ATM automation system provides support to the controller to
4. Recording of anomalous shear energy in the teleseismic P-wave coda at Long Valley Caldera, California, on a small aperture array
SciTech Connect
Zucca, J.J.; Zandt, G. (Lawrence Livermore National Lab., CA (USA)); Steck, L.K.; Prothero, W.A. (California Univ., Santa Barbara, CA (USA). Dept. of Geology)
1990-03-01
Anomalous energy in the coda of teleseismic P-waves at Long Valley caldera has been suggested to be a P to S converted arrival, perhaps with the conversion occurring at the boundaries of magma bodies beneath the caldera. We have collected new data with a small-aperture, three-component array located in the northwestern quadrant of the caldera with the purpose of testing this hypothesis. An examination of three teleseismic events using array and particle motion techniques shows that converted P- to S-waves comprise a significant fraction of the early arriving anomalous energy. In volcanic areas such as Long Valley, the scattered energy could originate at a high velocity contrast feature such as magma body interface. In addition, later arriving energy was detected with slow phase velocity and is tentatively identified as body wave to surface wave scattering. Our interpretation is illustrated with waveforms of two earthquakes from the Kuril Islands and one in northern Peru. Our results show that a small-aperture, three-component array can be used to perform detailed analysis of the coda. 12 refs., 8 figs., 1 tab.
5. Scattering of teleseismic P-waves by the Japan Trench: A significant effect of reverberation in the seawater column
Maeda, Takuto; Furumura, Takashi; Obara, Kazushige
2014-07-01
We detected a scattered wave train in data from the high-sensitivity seismograph network in Japan (Hi-net) following the arrival of the near-vertically incident P-wave generated by the 2009 earthquake (Mw 7.8) off the South Island of New Zealand. The scattered wave train represented predominantly vertical ground motion at a period of 20 to 50 s and with an apparent velocity of 3.5 km/s; it propagated cylindrically westward through the Kanto area of central Japan. Array analysis showed that the scattered wave train developed beneath the Pacific Ocean near the Boso triple junction, southeast of the Kanto area. A 3D finite-difference simulation of seismic wave propagation using a high-resolution model incorporating subsurface structure, topography, and bathymetry revealed that the strong scattered waves that were generated along the Japan Trench and propagated normal to the trench axis represented multiple reverberations of seismic waves between the seafloor and the Pacific plate boundary. In addition, strong reverberation of acoustic waves in the seawater column above the Boso triple junction causes elongated scattered waves, which reasonably explains our observations.
6. Teleseismic P-wave Tomography and Dynamic Processes of the Tien Shan Orogenic Belt in Central Asia
Lei, J.; Zhao, D.
2006-12-01
In this study, an updated version of the teleseismic tomographic method is applied to 7176 high-quality first P- wave arrivals from four combined seismic networks to determine the detailed deep structure under the central Tien Shan. Our high-resolution tomographic model not only displays the general features contained in the previous model, but also reveals some new features. A much narrower titled columnar high-velocity anomaly with a diameter of about 60 km below 150-200 km under the Tien Shan extends down to the mantle transition zone, suggesting that the breaking- and dropping-off of the collided portions of the southward underthrusting Kazakh Shield and the northward underthrusting Tarim Basin. Prominent low-velocity anomalies above 150-200 km depth beneath the Tien Shan may be related to two branches of ascending low-velocity anomalies. The one is from the lower mantle beneath the Tarim Basin. The other is from the top of the mantle transition zone beneath the western Kazakh Shield. These results suggest that the underthrusting of the Tarim Basin and Kazakh Shield and the upwelling of low-V anomalies indeed play an important role in the mountain building of the central Tien Shan. These dynamic processes might be related to the collision of the Indian with Eurasian plate.
7. Teleseismic P-wave tomography and the upper mantle structure of the central Tien Shan orogenic belt
Lei, Jianshe; Zhao, Dapeng
2007-07-01
In this study, an updated version of the teleseismic tomographic method is applied to 7176 high-quality first P-wave arrivals from four combined seismic networks to determine the detailed deep structure under the central Tien Shan. Our high-resolution tomographic model not only displays the general features contained in the previous models, but also reveals some new features. A much narrower tilted columnar high-velocity anomaly with a diameter of about 60 km below 150-200 km depth under the Tien Shan extends down to the mantle transition zone, suggesting the breaking- and dropping-off of the collided portions of the southward underthrusting Kazakh Shield and the northward underthrusting Tarim Basin. Prominent low-velocity (low-V) anomalies above 150-200 km depth beneath the Tien Shan may be related to two branches of ascending hot anomalies. One rises upward from the lower mantle beneath the Tarim Basin, while the other rises up from the top of the mantle transition zone beneath the western Kazakh Shield. These results suggest that the underthrusting of the Tarim Basin and Kazakh Shield and the upwelling of hot anomalies indeed play an important role in the mountain building of the central Tien Shan. These dynamic processes might be related to the collision of the Indian plate with Eurasian plate.
8. Geohydrology of the unsaturated zone and simulated time of arrival of landfill leachate at the water table, municipal solid waste landfill facility, US Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas
USGS Publications Warehouse
Frenzel, Peter F.; Abeyta, Cynthia G.
1999-01-01
The U.S. Air Defense Artillery Center and Fort Bliss Municipal Solid Waste Landfill Facility (MSWLF) is located about 10 miles northeast of downtown El Paso, Texas. The landfill is built on the Hueco Bolson, a deposit that yields water to five public-supply wells within 1.1 miles of the landfill boundary on all sides. The bolson deposits consist of lenses and mixtures of sand, clay, silt, gravel, and caliche. The unsaturated zone at the landfill is about 300 feet thick. The Hydrologic Evaluation of Landfill Performance (HELP) and the Multimedia Exposure Assessment Model for Evaluating the Land Disposal of Wastes (MULTIMED) computer models were used to simulate the time of first arrival of landfill leachate at the water table. Site-specific data were collected for model input. At five sites on the landfill cover, hydraulic conductivity was measured by an in situ method; in addition, laboratory values were obtained for porosity, moisture content at field capacity, and moisture content at wilting point. Twenty-seven sediment samples were collected from two adjacent boreholes drilled near the southwest corner of the landfill. Of these, 23 samples were assumed to represent the unsaturated zone beneath the landfill. The core samples were analyzed in the laboratory for various characteristics required for the HELP and MULTIMED models: initial moisture content, dry bulk density, porosity, saturated hydraulic conductivity, moisture retention percentages at various suction values, total organic carbon, and pH. Parameters were calculated for the van Genuchten and Brooks-Corey equations that relate hydraulic conductivity to saturation. A reported recharge value of 0.008 inch per year was estimated on the basis of soil- water chloride concentration. The HELP model was implemented using input values that were based mostly on site-specific data or assumed in a conservative manner. Exceptions were the default values used for waste characteristics. Flow through the landfill was assumed to be at steady state. The HELP-estimated landfill leakage rate was 101.6 millimeters per year, approximately 500 times the estimated recharge rate for the area near the landfill. The MULTIMED model was implemented using input values that were based mainly on site-specific data and some conservatively assumed values. Landfill leakage was assumed to begin when the landfill was established and to continue at a steady-state rate of 101.6 millimeters per year as estimated by the HELP model. By using an assumed solute concentration in the leachate of 1 milligram per liter and assuming no delay or decay of solute, the solute serves as a tracer to indicate the first arrival of landfill leachate. The simulated first arrival of leachate at the water table was 204 to 210 years after the establishment of the landfill.
9. Spatial and Temporal Variations in t s \\/t p and in P Wave Residuals at Blue Mountain Lake, New York: Application to Earthquake Prediction
Yash P. Aggarwal; Lynn R. Sykes; David W. Simpson; Paul G. Richards
1975-01-01
Renewed earthquake activity at Blue Mountain Lake (BML), New York, in July 1973 provided an excellent opportunity to monitor the travel time ratio of to P waves (ts\\/t,) in real time and to test the ts\\/t, technique as a predictive tool. From a mean value of 1.73 on July 30, 1973, ts\\/t, decreased to about 1.5 over the next 10. Gamma-Ray Burst Arrival Time Localizations: Simultaneous Observations by {ital Pioneer} {ital V}{ital enus} {ital Orbiter}, {ital Compton} {ital Gamma}-{ital Ray} {ital Observatory}, and {ital Ulysses} SciTech Connect Laros, J.G. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)] [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States); Hurley, K.C. [Space Sciences Laboratory, University of California, Berkeley, Berkeley, CA 94720-7450 (United States)] [Space Sciences Laboratory, University of California, Berkeley, Berkeley, CA 94720-7450 (United States); Fenimore, E.E.; Klebesadel, R.W. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Briggs, M.S. [University of Alabama in Huntsville, Huntsville, AL 35899 (United States)] [University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Kouveliotou, C.; McCollough, M.L. [USRA, at NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States)] [USRA, at NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Fishman, G.J.; Meegan, C.A. [NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States)] [NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Cline, T.L. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Boer, M.; Niel, M. [CESR, F-31029 Toulouse Cedex (France)] [CESR, F-31029 Toulouse Cedex (France) 1998-10-01 Between the {ital Compton} {ital Gamma} {ital Ray} {ital Observatory} ({ital CGRO}) launch in 1991 April and the {ital Pioneer} {ital V}{ital enus} {ital Orbiter} ({ital PVO}) demise in 1992 October, concurrent coverage by {ital CGRO}, {ital PVO}, and {ital Ulysses} was obtained for several hundred gamma-ray bursts (GRBs). Although most of these were below the {ital PVO} and {ital Ulysses} thresholds, 37 were positively detected by all three spacecraft, with data quality adequate for quantitative localization analysis. All were localized independently to {approximately}2{degree} accuracy by the {ital CGRO} Burst and Transient Source Experiment (BATSE), and three were also localized by COMPTEL. We computed arrival-time error boxes, whose larger dimensions range from about 2{prime} to several degrees and whose smaller dimensions are in the arcminute range. Twelve have areas less than 10 arcmin{sup 2}, and only four have areas greater than 1 deg{sup 2}. The area of the smallest box is 0.44 arcmin{sup 2}. We find that the overall BATSE localization accuracy for these events is consistent with the most recent stated uncertainties. This work indicates that the {ital ROSAT} soft X-ray source found within a preliminary IPN error box for GB920501 (Trig 1576) (Hurley et al.) is less likely to be the GRB counterpart than previously reported. {copyright} {ital {copyright} 1998.} {ital The American Astronomical Society} 11. Imaging the Juan de Fuca plate beneath southern Oregon using teleseismic P wave residuals USGS Publications Warehouse Harris, R.A.; Iyer, H.M.; Dawson, P.B. 1991-01-01 Images the Juan de Fuca plate in southern Oregon using seismic tomography. P wave travel time residuals from a 366-km-long seismic array operated in southern Oregon in 1982 are inverted. The southeast striking array extended from the Coast ranges to the Modoc Plateau and crossed the High Cascades at Crater Lake, Oregon. Three features under the array were imaged: one high-velocity zone and two low-velocity zones. The high-velocity zone is 3-4% faster than the surrounding upper mantle. It dips steeply at 65?? to the east beneath the Cascade Range and extends down to at least 200 km. It is proposed that this high-velocity feature is subducted Juan de Fuca plate. Two low-velocity zones were also imaged, both of which are 3-4% slower than the surrounding earth structure. The southeastern low-velocity zone may be caused by partially molten crust underlying the Crater Lake volcano region. -from Authors 12. Upper mantle and crustal P-wave attenuation beneath the North Korea region NASA Astrophysics Data System (ADS) Cleveland, M.; Randall, G. E.; Patton, H. J.; Phillips, W. S. 2014-12-01 Accurate estimation of the magnitude of crustal seismic sources is dependent upon a strong understanding of the anelastic P-wave attenuation in the crust and upper mantle. In this study, we estimate the crustal/upper mantle average attenuation (t*) for the region around North Korea by expanding upon methods described by Ichinose et al. [2013]. We estimate t* by modeling the observed spectra and spectral ratio of regional and teleseismic P- and pP-phases of large, deep (> 500 km) earthquakes rupturing beneath the North Korea region. We use seismograms, acquired from the IRIS data archive, from operational stations at the time of each earthquake. Because of a trade-off between the variables, we use multi-variable optimization to estimate the best-fitting corner frequency (fc) and t* for each spectrum. In addition to using a more quantitative and global approach than earlier studies, we introduce new measurement approaches enabling a better understanding of the uncertainty in the measured t* value and its trade-off with fc. 13. What Do s- and p-Wave Neutron Average Radiative Widths Reveal SciTech Connect Mughabghab, S.F. 2010-04-30 A first observation of two resonance-like structures at mass numbers 92 and 112 in the average capture widths of the p-wave neutron resonances relative to the s-wave component is interpreted in terms of a spin-orbit splitting of the 3p single-particle state into P{sub 3/2} and P{sub 1/2} components at the neutron separation energy. A third structure at about A = 124, which is not correlated with the 3p-wave neutron strength function, is possibly due to the Pygmy Dipole Resonance. Five significant results emerge from this investigation: (i) The strength of the spin-orbit potential of the optical-model is determined as 5.7 {+-} 0.5 MeV, (ii) Non-statistical effects dominate the p-wave neutron-capture in the mass region A = 85 - 130, (iii) The background magnitude of the p-wave average capture-width relative to that of the s-wave is determined as 0.50 {+-} 0.05, which is accounted for quantitatively in tenns of the generalized Fermi liquid model of Mughabghab and Dunford, (iv) The p-wave resonances arc partially decoupled from the giant-dipole resonance (GDR), and (v) Gamma-ray transitions, enhanced over the predictions of the GDR, are observed in the {sup 90}Zr - {sup 98}Mo and Sn-Ba regions. 14. Chiral superfluidity with p-wave symmetry from an interacting s-wave atomic Fermi gas NASA Astrophysics Data System (ADS) Liu, Bo; Li, Xiaopeng; Wu, Biao; Liu, W. Vincent 2014-09-01 Chiral p-wave superfluids are fascinating topological quantum states of matter that have been found in the liquid 3He-A phase and arguably in the electronic Sr2RuO4 superconductor. They are fundamentally related to the fractional 5/2 quantum Hall state, which supports fractional exotic excitations. Past studies show that they require spin-triplet pairing of fermions by p-wave interaction. Here we report that a p-wave chiral superfluid state can arise from spin-singlet pairing for an s-wave interacting atomic Fermi gas in an optical lattice. This p-wave state is conceptually distinct from all previous conventional p-wave states as it is for the centre-of-mass motion, instead of the relative motion. It leads to spontaneous generation of angular momentum, finite Chern numbers and topologically protected chiral fermionic zero modes bounded to domain walls, all occuring at a higher critical temperature in relative scales. Signature quantities are predicted for the cold atom experimental condition. 15. Fluorescence Assay for Polymerase Arrival Rates E-print Network Che, Austin 2003-08-31 To engineer complex synthetic biological systems will require modular design, assembly, and characterization strategies. The RNA polymerase arrival rate (PAR) is defined to be the rate that RNA polymerases arrive at a ... 16. Fluorescence assay for polymerase arrival rates E-print Network Che, Austin, 1979- 2004-01-01 To engineer complex synthetic biological systems will require modular design, assembly, and characterization strategies. The RNA polymerase arrival rate (PAR) is defined to be the rate that RNA polymerases arrive at a ... 17. Multistatic Pulse-Wave Angle-of-arrival-assisted relative interferometric RADAR Microsoft Academic Search Jonathan Friedman; Thomas Schmid; Zainul Charbiwala; Mani B. Srivastava; Y. H. Cho 2009-01-01 In this work we propose a Pulse-Wave (PW) extension to the Angle-of-arrival-assisted Radio Interferometry (ARI) technique to dramatically reduce the scan-time and the number of vantage points necessary to obtain high-fidelity target position estimation. Accordingly, we call this enhanced process PW-ARI. PW-ARI is the fusion of data from three domains: time (time-of-flight), phase (relative phase-of-arrival), and angle (direction-of-arrival). It has 18. Direction of arrival measurements at UHF Microsoft Academic Search P. A. Matthews; B. Mohebbi 1989-01-01 Direction of arrival measurements have been made at 870 MHz using land mobile radio systems in an urban environment. Examples are given showing the multipath components arriving at the receiver after reflection and scattering from buildings. A synthetic aperture technique is used to measure the directions of arrival. 19. Saskatoon | Saskatchewan | Canada Pre-Arrival E-print Network Peak, Derek Saskatoon | Saskatchewan | Canada Pre-Arrival Guidefor International Students Studious Ingenious to the University of Saskatchewan (U of S). We are very pleased that you have chosen our university as your place Outstanding Documentation | 21 University of Saskatchewan Pre-Arrival Guide 1 #12;BeforeYouArrive Apply 20. P-wave-enhanced spin field effect transistor and recent patents. PubMed Gau, Ming-Hong; Lo, Ikai; Wang, Wan-Tsang; Chiang, Jih-Chen; Chou, Mitch Ming-Chi 2007-01-01 P-wave-enhanced spin field-effect transistor made of AlGaN/GaN heterostructure was designed for the spintronic devices operated at high power and high temperature. The operation theory is based on the spin-polarized field-effect transistor designed by Datta and Das [Appl. Phys. Lett. 56, 665 (1990)]. The mechanism of the p-wave enhancement in AlGaN/GaN heterostructure was investigated. The recent development and related patents in the spin-polarized field-effect transistor were reviewed. In particular, we will focus on the recent patents which could enhance p-wave probability and control of spin precession of 2DEG in the AlGaN/GaN transistor structure. PMID:19076030 1. Factors Influencing Intracavitary Electrocardiographic P-Wave Changes during Central Venous Catheter Placement PubMed Central Wang, Guorong; Guo, Ling; Jiang, Bin; Huang, Min; Zhang, Jian; Qin, Ying 2015-01-01 Amplitude changes in the P-wave of intracavitary electrocardiography have been used to assess the tip placement of central venous catheters. The research assessed the sensitivity and specificity of this sign in comparison with standard radiographic techniques for tip location, focusing on factors influencing its clinical utility. Both intracavitary electrocardiography guided tip location and X-ray positioning were used to verify catheter tip locations in patients undergoing central venous catheter insertion. Intracavitary electrocardiograms from 1119 patients (of a total 1160 subjects) showed specific amplitude changes in the P-wave. As the results show, compared with X-ray positioning, the sensitivity of electrocardiography-guided tip location was 97.3%, with false negative rate of 2.7%; the specificity was 1, with false positive rate of zero. Univariate analyses indicated that features including age, gender, height, body weight, and heart rate have no statistically significant influence on P-wave amplitude changes (P>0.05). Multivariate logistic regression revealed that catheter insertion routes (OR = 2.280, P = 0.003) and basal P-wave amplitude (OR = 0.553, P = 0.003) have statistically significant impacts on P-wave amplitude changes. As a reliable indicator of tip location, amplitude change in the P-wave has proved of good sensitivity and excellent specificity, and the minor, zero, false positive rate supports the clinical utility of this technique in early recognition of malpositioned tips. A better sensitivity was achieved in placement of centrally inserted central catheters (CICCs) than that of peripherally inserted central catheters (PICCs). In clinical practice, a combination of intracavitary electrocardiography, ultrasonic inspection and the anthropometric measurement method would further improve the accuracy. PMID:25915758 2. Near-surface seismic attenuation of P-waves in West Texas E-print Network Al-Zahrani, Said Awdhah 1992-01-01 NEAR-SURFACE SEISMIC ATTENUATION OF P-WAVES IN WEST TEXAS A Thesis by SAID AWDHAH AL-ZAHRANI Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1992 Major Subject: Geophysics NEAR-SURFACE SEISMIC ATTENUATION OF P-WAVES IN WEST TEXAS A Thesis by SAID AWDHAH AL-ZAHRANI Approved as to style and content by: Steven H. arder (Chair of Committee) rry W. S neer (Me ber) I S. Watkins... 3. Delay analysis of bursty tasks using workload arrival functions E-print Network Kim, Junwhan 2001-01-01 During the time interval [0, t), if the total tasks leaving processor j is W, (t), the time H, (t) when Wi(t) ? th task arrives at processor j is given as H, (t) = G, '(W, (t)). (2 9) Note: Hi(t) & t. LEMMA 5 If the total amount of tasks arriving...-to-end delay analysis, which better take into account delay dependencies. Algorithm Integrated, described in Figure 5, computes end-to-end delays in a cycle-free network with processors sched- uled by FIFO order. It first partitions the network... 4. Confinement-induced p-wave resonances from s-wave interactions E-print Network Yusuke Nishida; Shina Tan 2010-12-27 We show that a purely s-wave interaction in three dimensions (3D) can induce higher partial-wave resonances in mixed dimensions. We develop two-body scattering theories in all three cases of 0D-3D, 1D-3D, and 2D-3D mixtures and determine the positions of higher partial-wave resonances in terms of the 3D s-wave scattering length assuming a harmonic confinement potential. We also compute the low-energy scattering parameters in the p-wave channel (scattering volume and effective momentum) that are necessary for the low-energy effective theory of the p-wave resonance. We point out that some of the resonances observed in the Florence group experiment [Phys. Rev. Lett. 104, 153202 (2010)] can be interpreted as the p-wave resonances in the 2D-3D mixed dimensions. Our study paves the way for a variety of physics, such as Anderson localization of matter waves under p-wave resonant scatterers. 5. Magnitude estimation using the first three seconds P-wave amplitude in earthquake early warning E-print Network Wu, Yih-Min Magnitude estimation using the first three seconds P-wave amplitude in earthquake early warning Yih as a function of magnitude M, and obtained the following relationship: log (Pd) = À3.463 + 0.729 Â M À 1.374 Â to the epicenter, this relationship can be used to define a so-called Pd magnitude'' of earthquakes. Our result 6. Polarization, phase velocity and NMO velocity of qP waves in arbitrary weakly anisotropic media E-print Network Cerveny, Vlastislav ). Accuracy of presented formulae is tested on two examples of anisotropic media with relatively strongPolarization, phase velocity and NMO velocity of qP waves in arbitrary weakly anisotropic media) in isotropic media, the WA parameters are zero and the corresponding equations reduce to equations 7. A model for P-wave attenuation and dispersion in a porous medium ... E-print Network lll 2005-09-05 fluid-saturated porous medium composed of two constituents, b and c can be ... 376. M. Brajanovski, B. Gurevich and M. Schoenberg. The results presented in this .... 9 ??µ?. K2 g . (30). As with the frequency-dependent P-wave modulus, the 8. Investigation of semileptonic B meson decays to p-wave charm mesons E-print Network Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan 1998-05-01 We have studied semileptonic B meson decays with a p-wave charm meson in the final state using 3.29 x 10(6) B (B) over bar events collected with the CLEO II detector at the Cornell Electron-Positron Storage Ring. We find ... 9. ccsd-00004932,version3-13Feb2006 Modeling interactions for resonant p-wave scattering E-print Network Paris-Sud XI, Université de experiments on ultra-cold polarized fermions, the zero-range potential approach is generalized to situations interactions is introduced. This formalism is used in the context of ultra-cold spin-polarized fermions, whereccsd-00004932,version3-13Feb2006 Modeling interactions for resonant p-wave scattering Ludovic 10. P-wave Local Earthquake Tomography in the Central Alborz Mountains, Iran NASA Astrophysics Data System (ADS) Mostafanejad, A.; Hosein Shomali, Z. 2010-12-01 The Alborz Mountain ranges in the southern margin of the Caspian Sea, as a part of the Alpine- Himalayan orogenic belt is an arc of parallel synclines and anticlines. Among the major tectonic and geological features of the Alborz Mountains are the Damavand quaternary volcano, and active and seismic faults like the Mosha, and North Tehran faults. In this study, the first 3D P-wave velocity model of the upper crust in the Central Alborz Mountains is obtained using a local travel-time earthquake tomography method. A data set of 895 earthquakes recorded on a local 19 station short-period network between 1996 and 2006 provided by the Iranian Seismological Centre (ISC) is used in this inversion. The result of tomography shows considerable velocity anomalies in this region. These anomalies show remarkable features in the vicinity of the Mosha and North Tehran faults, as well as in the Damavand volcanic area. In depth of 15 kilometer a low velocity region is observed parallel to the above two mentioned faults. This can be caused by the crushed rocks along these two faults. In the place of splitting North Tehran fault from the Mosha fault, a very noticeable low velocity anomaly represents intense fracturing in rocks. In the Damavand volcanic area and in the northern side of the summit an anomalous high velocity body found to the depth of 20 kilometer. According to its considerable correlation with the position of the old Damavand cone, it is related to the older and crystallized magma chamber of the Damavand volcano. A low velocity anomaly exactly beneath the present cone to the depth of seven kilometer, with another low velocity anomaly in depth of 10 to 20 kilometer constitutes the present magma chamber of the Damavand volcano. 11. Predicting travel times for a broad suite of seismic phases with full 3-D ray tracing NASA Astrophysics Data System (ADS) Simmons, N. A.; Myers, S. C.; Johannesson, G.; Matzel, E. 2013-12-01 We recently constructed a global-scale P-wave model (LLNL-G3D version 3, Simmons et al. 2012, JGR) designed to predict travel times for the first arriving P-wave energy at regional and teleseismic distances (Pn and P phases). The model is complex with undulating structures explicitly represented including 7 crustal units, the Moho, and the upper mantle phase transitions. The explicit aspherical representation of the Earth is required to perform true 3-D ray tracing, which was employed to construct the model. Our tests have demonstrated a significant improvement in event location accuracy using P and Pn travel times predicted from the LLNL-G3D model. There is a need to predict additional seismic phases using a single model so that the travel times are self-consistent. Therefore, we are developing full 3-D ray tracing procedures for additional seismic phases (pP, PcP, PKP branches, PP, S phases). We will demonstrate the ability (or inability) of the current model to predict some of these travel times and explore the usefulness of these arrivals in constructing the next version of the LLNL-G3D model. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-641528 12. Anisotropic changes in P-wave velocity and attenuation during deformation and fluid infiltration of granite USGS Publications Warehouse Stanchits, S.A.; Lockner, D.A.; Ponomarev, A.V. 2003-01-01 Fluid infiltration and pore fluid pressure changes are known to have a significant effect on the occurrence of earthquakes. Yet, for most damaging earthquakes, with nucleation zones below a few kilometers depth, direct measurements of fluid pressure variations are not available. Instead, pore fluid pressures are inferred primarily from seismic-wave propagation characteristics such as Vp/Vs ratio, attenuation, and reflectivity contacts. We present laboratory measurements of changes in P-wave velocity and attenuation during the injection of water into a granite sample as it was loaded to failure. A cylindrical sample of Westerly granite was deformed at constant confining and pore pressures of 50 and 1 MPa, respectively. Axial load was increased in discrete steps by controlling axial displacement. Anisotropic P-wave velocity and attenuation fields were determined during the experiment using an array of 13 piezoelectric transducers. At the final loading steps (86% and 95% of peak stress), both spatial and temporal changes in P-wave velocity and peak-to-peak amplitudes of P and S waves were observed. P-wave velocity anisotropy reached a maximum of 26%. Transient increases in attenuation of up to 483 dB/m were also observed and were associated with diffusion of water into the sample. We show that velocity and attenuation of P waves are sensitive to the process of opening of microcracks and the subsequent resaturation of these cracks as water diffuses in from the surrounding region. Symmetry of the orientation of newly formed microcracks results in anisotropic velocity and attenuation fields that systematically evolve in response to changes in stress and influx of water. With proper scaling, these measurements provide constraints on the magnitude and duration of velocity and attenuation transients that can be expected to accompany the nucleation of earthquakes in the Earth's crust. 13. Effects of exciting frequencies, grain sizes, and damage upon P-wave velocity for ultrasonic NDT of concrete Microsoft Academic Search Jiann W. Ju; Lisheng Weng 2000-01-01 This paper focuses on the experimental study of the effects of exciting frequencies, grain (aggregate) sizes, and damage upon the ultrasonic P-wave velocity when performing the ultrasonic nondestructive testing (NDT) for concrete specimens. Two batches of concrete and mortar specimens were prepared in the laboratory for the investigation of the effects from the stated factors upon the P-wave velocity. Damage 14. P-wave velocity structure of the crust and uppermost mantle beneath Iceland from local earthquake tomography E-print Network Shen, Yang P-wave velocity structure of the crust and uppermost mantle beneath Iceland from local earthquake tomography Ting Yang*, Yang Shen Graduate School of Oceanography, University of Rhode Island, South Ferry develop a three-dimensional P-wave velocity model of the Icelandic crust and uppermost mantle from 15. Delaying the Catastrophic Arrival of the Brown Tree Snake to Hawaii Microsoft Academic Search Kimberly Burnett; James Roumasset; Yacov Tsur 2007-01-01 This paper develops a two-stage model for the optimal management of a potential invasive species. The arrival of an invasive species is modeled as an irreversible event with an uncertain arrival time. The model is solved in two stages, beginning with the post-invasion stage. In this stage, we assume perfect certainty regarding population size and arrivals. The loss-minimizing paths of 16. Reallocating arrival slots during a ground delay program Microsoft Academic Search Jonathan F. Bard; Dinesh Natarajan Mohan 2008-01-01 This paper presents a new model and solution methodology for the arrival slot reallocation problem faced by airlines when responding to a ground delay program (GDP). The objective is to reassign the flights in the GDP to time slots made available by the Federal Aviation Administration (FAA) such that flight delay and passenger missed connection costs are minimized. The problem 17. Anchorage Arrival Scheduling Under Off-Nominal Weather Conditions NASA Technical Reports Server (NTRS) Grabbe, Shon; Chan, William N.; Mukherjee, Avijit 2012-01-01 Weather can cause flight diversions, passenger delays, additional fuel consumption and schedule disruptions at any high volume airport. The impacts are particularly acute at the Ted Stevens Anchorage International Airport in Anchorage, Alaska due to its importance as a major international portal. To minimize the impacts due to weather, a multi-stage scheduling process is employed that is iteratively executed, as updated aircraft demand and/or airport capacity data become available. The strategic scheduling algorithm assigns speed adjustments for flights that originate outside of Anchorage Center to achieve the proper demand and capacity balance. Similarly, an internal departure-scheduling algorithm assigns ground holds for pre-departure flights that originate from within Anchorage Center. Tactical flight controls in the form of airborne holding are employed to reactively account for system uncertainties. Real-world scenarios that were derived from the January 16, 2012 Anchorage visibility observations and the January 12, 2012 Anchorage arrival schedule were used to test the initial implementation of the scheduling algorithm in fast-time simulation experiments. Although over 90% of the flights in the scenarios arrived at Anchorage without requiring any delay, pre-departure scheduling was the dominant form of control for Anchorage arrivals. Additionally, tactical scheduling was used extensively in conjunction with the pre-departure scheduling to reactively compensate for uncertainties in the arrival demand. For long-haul flights, the strategic scheduling algorithm performed best when the scheduling horizon was greater than 1,000 nmi. With these long scheduling horizons, it was possible to absorb between ten and 12 minutes of delay through speed control alone. Unfortunately, the use of tactical scheduling, which resulted in airborne holding, was found to increase as the strategic scheduling horizon increased because of the additional uncertainty in the arrival times of the aircraft. Findings from these initial experiments indicate that it is possible to schedule arrivals into Anchorage with minimal delays under low-visibility conditions with less disruption to high-cost, international flights. 18. Teleseismic travel times, the Isabella anomaly, and the missing Moho, from the Sierra Nevada EarthScope experiment NASA Astrophysics Data System (ADS) Thomas, A.; Jones, C.; Reeg, H.; Gilbert, H.; Zandt, G.; Owens, T. 2005-12-01 Seismic studies of the southern and central Sierra Nevada revealed a region within the western foothills where the teleseismic P to S Moho conversion is very weak or absent (Zandt et al., Nature, 2004; Burdick et al., this meeting). The conversion could be destroyed by a downward pointing cusp on the Moho produced as crust is entrained in the foundering of the garnet-rich Sierran lower crustal root. The first phase of the recently deployed Sierra Nevada Earthscope Project (SNEP) consists of an array of over 40 broadband seismometers spanning the central Sierra Nevada for a ~15-month period. Initial examination of the new teleseismic travel times from the SNEP stations reveal earlier P-wave arrivals above the "missing" Moho than in the surrounding area. These P-arrivals appear to be inconsistent with the concept of the downward cusp on the Moho: if there were a thicker crust where the Moho is "missing" then the P-wave arrivals in that area should be later than in surrounding areas. P-wave residuals, some of which are more than a second early, indicate that a subsurface high wavespeed body is instead present; these residuals are in part due to the previously described "Isabella anomaly" under the southwestern Sierra. By evaluating the P-wave arrival times from 30 different teleseisms to the SNEP,1997 Sierran Paradox, and 1988 Southern Sierra experiments, we can approximate the spatial geometry of the body or bodies as an elongated body plunging toward the southeast. A preliminary cross section of teleseismic P-residuals using events from the northwest and southeast suggests that the anomaly extends from less than 30 km to as much as 250 km depth. Quite possibly two anomalies exist: one near the Moho in the northwest and one closer to 200 km depth to the southeast. The shallow level of the upper, northwestern end of the body suggests that the "Moho hole" might instead reflect a region where high-wavespeed material exists in the crust, diminishing the contrast at the Moho and thus disrupting the Ps conversion, or that high-wavespeed material overwhelms the effect of thickened crust in this area. The lower bound on the bottom of the Isabella anomaly suggests that the entire foundering body remains in the uppermost mantle and that completed imaging from the combined 1988, 1997, and SNEP experiments will finally complete our picture of this enigmatic body. 19. Rapid estimation of earthquake size using the broadband P-wave magnitude mB NASA Astrophysics Data System (ADS) Saul, J.; Bormann, P. 2007-12-01 The size of an earthquake is the most fundamental characteristic besides its location. In order to adequately respond to an earthquake, especially when human life is at stake, an accurate size estimate must be available rapidly. Quick quantification of earthquake magnitude, however, continues to present a challenge particularly for large events. Especially following the disastrous December 26, 2004, Sumatra-Andaman event, a number of new methods have been proposed to overcome this difficulty. As early as 1956, Gutenberg and Richter introduced the body wave magnitude mB = log10(A/T)max + Q(?,z). They determined the displacement amplitude A and dominant period T from intermediate- period displacement seismograms. The calibration function Q was derived accordingly. Later the same formula and calibration function was adopted for the narrow-band, WWSSN short-period magnitude mb, resulting in systematically underestimated magnitudes for events larger than about 5.5. We demonstrate that by using the full broadband P-waveform, the original but long-forgotten mB provides excellent magnitude estimates up to at least magnitude 8. It is probably the simplest of all P-wave based magnitudes, since modern broadband instruments record ground velocity directly and (A/T)max may simply be replaced by Vmax/2?. Based on broadband recordings of more than 1000 large earthquakes since 1990, we derived a new mB calibration function, spanning the distance range from 5 to 100 degrees. By using this calibration function, first mB estimates may become available after as little as 2 minutes following the origin time. The trivially simple computation makes mB a competitor for MWP. The latter involves double integration of velocity seismograms and is known to suffer from stability problems. Furthermore, it is highly susceptible to noise. In contrast, mB is guaranteed to be numerically stable and noise is of less concern. This is an important consideration especially in automated setups where processing speed is crucial and time-consuming manual interaction has to be avoided. 20. ECG manifestations of multiple electrolyte imbalance: peaked T wave to P wave ("tee-pee sign"). PubMed Johri, Amer M; Baranchuk, Adrian; Simpson, Christopher S; Abdollah, Hoshiar; Redfearn, Damian P 2009-04-01 The surface electrocardiogram (ECG) is a useful instrument in the detection of metabolic disturbances. The accurate characterization of these disturbances, however, may be considerably more difficult when more than one metabolic abnormality is present in the same individual. While "classic" ECG presentations of common electrolyte disturbances are well described, multiple electrolyte disturbances occurring simultaneously may generate ECG abnormalities that are not as readily recognizable. We report a case of hyperkalemia, with concurrent hypocalcemia and hypomagnesemia resulting in (1) peaking of the T wave, (2) a prominent U wave, and (3) prolongation of the descending limb of the T wave such that it overlapped with the next P wave. In this particular ECG from a patient with combined electrolyte imbalance, we have dubbed the unusual appearance of the segment between the peak of the T wave to the next P wave as the "tee-pee" sign. PMID:19419407 1. The Galileo arrival date selection process NASA Technical Reports Server (NTRS) Ludwinski, Jan M.; Gershman, Robert 1988-01-01 The Galileo arrival date selection process has culminated in the selection of December 7,1995. This arrival date will provide excellent science opportunities at Jupiter as well as the first spacecraft reconnaissance ever of not one, but two asteroids during the cruise to Jupiter. 2. Illuminating the near-sonic rupture velocities of the intracontinental Kokoxili Mw 7.8 and Denali fault Mw 7.9 strike-slip earthquakes with global P wave back projection imaging Microsoft Academic Search Kristoffer T. Walker; Peter M. Shearer 2009-01-01 The Denali and Kokoxili strike-slip earthquakes are two of the longest recent intracontinental ruptures. Previous studies report a range of rupture velocities. Here we image these earthquakes by reverse time migration of the intermediate-frequency P wave train recorded by global broadband seismometers. This technique permits a relatively direct measure of rupture velocity (speed and direction) as constrained by the radiated 3. Isolated vortex and vortex lattice in a holographic p-wave superconductor Microsoft Academic Search James M. Murray; Zlatko Tesanovic 2011-01-01 Using the holographic gauge-gravity duality, we find a solution for an isolated vortex and a vortex lattice in a 2+1-dimensional p-wave superconductor, which is described by the boundary theory dual to an SU(2) gauge theory in 3+1-dimensional anti-de Sitter space. Both px+ipy and px-ipy components of the superconducting order parameter, as well as the effects of a magnetic field on 4. P-Wave Velocity Structure and Its Tectonics beneath Dabie-Sulu Region Microsoft Academic Search J. Xu; Z. Zhao 2007-01-01 The 3-D crustal structure of P-wave velocity in the Dabie-Sulu region and the vicinities was studied based on the data obtained by wide-angle seismic reflection and refraction surveys. The results suggest that the high velocity structure zones exist in the upper crust shallower than 20 km beneath the Sulu and Dabie regions. The cause of high velocity zones is attributable 5. Rapid Assessment of Damage Potential of Earthquakes in Taiwan from the Beginning of P Waves Microsoft Academic Search Yih-Min Wu; Hiroo Kanamori 2005-01-01 To rapidly assess the potential for damage of an earthquake for purposes of earthquake early warning in Taiwan, we used the peak displacement and velocity amplitudes of the first 3 sec of the P wave. The vertical-component records, high- pass filtered at 0.075 Hz, are used. We found that the peak initial-displacement amplitude (Pd) correlates well with the peak ground-motion 6. Testable Signatures of Quantum Nonlocality in a Two-Dimensional Chiral p-Wave Superconductor SciTech Connect Tewari, Sumanta; Zhang Chuanwei; Das Sarma, S. [Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Nayak, Chetan [Microsoft Station Q, CNSI Building, University of California, Santa Barbara, California 93108 (United States); Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Lee, Dung-Hai [Department of Physics, University of California at Berkeley, Berkeley, California 94720 (United States); Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States) 2008-01-18 A class of topological excitations--the odd-winding number vortices--in a spinless 2D chiral p-wave (p{sub x}+ip{sub y}) superconductor traps Majorana fermion states in the vortex cores. For a dilute gas of such vortices, the lowest energy fermionic eigenstates are intrinsically nonlocal. We predict two testable signatures of this unusual quantum nonlocality in quasiparticle tunneling experiments. We discuss why the associated teleportationlike phenomenon does not imply the violation of causality. 7. Spin polarization and Zeeman effects in ferromagnet\\/ferromagnetic p -wave superconductor junctions Microsoft Academic Search Hong Li; Xinjian Yang 2011-01-01 An extended Blonder–Tinkham–Klapwijk (BTK) approach is applied to study the spin polarization and Zeeman effects in ferromagnet\\/ferromagnetic p-wave superconductor (FM\\/FpS) junctions. Three kinds of pairings for FpS are chosen: px,py,px+ipy waves. It is found that the normalized conductance strongly depends on both kinds of pairings and the relative orientations of the effective exchange field in the FM and FpS. In 8. Ferromagnetic insulator effects in ferromagnetic semiconductor\\/ferromagnetic insulator\\/ p-wave superconductor junctions Microsoft Academic Search Hong Li; Xinjian Yang 2009-01-01 The effect of the ferromagnetic insulator on tunneling conductance in ferromagnetic semiconductor\\/ferromagnetic insulator\\/p-wave superconductor (FS\\/FI\\/P) junctions is studied based on a scattering theory. Three kinds of pairings for the P side are chosen: px, py ,px+ipy waves. It is shown that the spin filtering effect originating from the exchange field in the FI strongly modifies the normalization conductance. Many novel 9. Input-output characterization of fiber reinforced composites by P waves NASA Technical Reports Server (NTRS) Renneisen, John D.; Williams, James H., Jr. 1990-01-01 Input-output characterization of fiber composites is studied theoretically by tracing P waves in the media. A new path motion to aid in the tracing of P and the reflection generated SV wave paths in the continuum plate is developed. A theoretical output voltage from the receiving transducer is calculated for a tone burst. The study enhances the quantitative and qualitative understanding of the nondestructive evaluation of fiber composites which can be modeled as transversely isotropic media. 10. Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography Microsoft Academic Search C. Berk Biryol; Susan L. Beck; George Zandt; A. Arda Özacar 2011-01-01 Lithospheric deformation throughout Anatolia, a part of the Alpine-Himalayan orogenic belt, is controlled mainly by collision-related tectonic escape of the Anatolian Plate and subduction roll-back along the Aegean Subduction Zone. We study the deeper lithosphere and mantle structure of Anatolia using teleseismic, finite-frequency, P-wave traveltime tomography. We use data from several temporary and permanent seismic networks deployed in the region. 11. A Study of the Core-Mantle Boundary Using P Waves Diffracted by the Earth's Core Microsoft Academic Search Shelton S. Alexander; Robert A. Phinney 1966-01-01 Ratios of the spectrums of diffracted P waves can be used to isolate effects of propagation along the core-mantle boundary, and the rate of attenuation with distance as a function of frequency is a useful quantitative measure of core-mantle properties. Spectrums of the attenuation coefficient for a number of patches on the core-mantle boundary were measured in the frequency range 12. Effect of cracks on the pressure dependence of P wave velocities in crystalline rocks Microsoft Academic Search Richard L. Carlson; Anthony F. Gangi 1985-01-01 To test the bed of nails'' model, we have made detailed measurements of P wave velocities in five low-porosity, crystalline rocks at effective pressures to 500 MPa and fit two equations based on the model to the laboratory data. The first equation, V(P) =V0(1+P\\/Pi)(1-m)\\/2, applies at relatively low pressures because it assumes that the grain modulus is very much larger 13. Quantum Phase Transition in the BCS-to-BEC Evolution of p -wave Fermi Gases Microsoft Academic Search S. S. Botelho; C. A. R. Sá de Melo 2005-01-01 We discuss the possibility of a quantum phase transition in ultra-cold spin-polarized Fermi gases which exhibit a p-wave Feshbach resonance. We show that when fermionic atoms form a condensate that can be externally tuned between the BCS and BEC limits, the zero temperature compressibility and the spin susceptibility of the fermionic gas are non-analytic functions of the two-body bound state 14. Permeability and P-wave velocity change in granitic rocks under freeze–thaw cycles Microsoft Academic Search M. Takarli; W. Prince 2007-01-01 An extensive experimental investigation of microstructural changes in granites under freeze–thaw cycles using permeability and P-wave velocity measurements is described. Two types of natural granite rocks are considered and tested under dry and saturated conditions. The specimens were subjected to 200 heating–cooling cycles (??20°C\\/?+?20°C); each cycle had a duration of 24 h. The results indicate that the ageing process decreases the 15. P-wave velocity structure of the uppermost mantle beneath Hawaii from traveltime tomography USGS Publications Warehouse Tilmann, F.J.; Benz, H.M.; Priestley, K.F.; Okubo, P.G. 2001-01-01 We examine the P-wave velocity structure beneath the island of Hawaii using P-wave residuals from teleseismic earthquakes recorded by the Hawaiian Volcano Observatory seismic network. The station geometry and distribution of events makes it possible to image the velocity structure between ~ 40 and 100 km depth with a lateral resolution of ~ 15 km and a vertical resolution of ~ 30 km. For depths between 40 and 80 km, P-wave velocities are up to 5 per cent slower in a broad elongated region trending SE-NW that underlies the island between the two lines defined by the volcanic loci. No direct correlation between the magnitude of the lithospheric anomaly and the current level of volcanic activity is apparent, but the slow region is broadened at ~ 19.8??N and narrow beneath Kilauea. In the case of the occanic lithosphere beneath Hawaii, slow seismic velocities are likely to be related to magma transport from the top of the melting zone at the base of the lithosphere to the surface. Thermal modelling shows that the broad elongated low-velocity zone cannot be explained in terms of conductive heating by one primary conduit per volcano but that more complicated melt pathways must exist. 16. Simulation Results for Airborne Precision Spacing along Continuous Descent Arrivals NASA Technical Reports Server (NTRS) Barmore, Bryan E.; Abbott, Terence S.; Capron, William R.; Baxley, Brian T. 2008-01-01 This paper describes the results of a fast-time simulation experiment and a high-fidelity simulator validation with merging streams of aircraft flying Continuous Descent Arrivals through generic airspace to a runway at Dallas-Ft Worth. Aircraft made small speed adjustments based on an airborne-based spacing algorithm, so as to arrive at the threshold exactly at the assigned time interval behind their Traffic-To-Follow. The 40 aircraft were initialized at different altitudes and speeds on one of four different routes, and then merged at different points and altitudes while flying Continuous Descent Arrivals. This merging and spacing using flight deck equipment and procedures to augment or implement Air Traffic Management directives is called Flight Deck-based Merging and Spacing, an important subset of a larger Airborne Precision Spacing functionality. This research indicates that Flight Deck-based Merging and Spacing initiated while at cruise altitude and well prior to the Terminal Radar Approach Control entry can significantly contribute to the delivery of aircraft at a specified interval to the runway threshold with a high degree of accuracy and at a reduced pilot workload. Furthermore, previously documented work has shown that using a Continuous Descent Arrival instead of a traditional step-down descent can save fuel, reduce noise, and reduce emissions. Research into Flight Deck-based Merging and Spacing is a cooperative effort between government and industry partners. 17. Finite-difference modelling to evaluate seismic P-wave and shear-wave field data NASA Astrophysics Data System (ADS) Burschil, T.; Beilecke, T.; Krawczyk, C. M. 2015-01-01 High-resolution reflection seismic methods are an established non-destructive tool for engineering tasks. In the near surface, shear-wave reflection seismic measurements usually offer a higher spatial resolution in the same effective signal frequency spectrum than P-wave data, but data quality varies more strongly. To discuss the causes of these differences, we investigated a P-wave and a SH-wave seismic reflection profile measured at the same location on the island of Föhr, Germany and applied seismic reflection processing to the field data as well as finite-difference modelling of the seismic wave field. The simulations calculated were adapted to the acquisition field geometry, comprising 2 m receiver distance (1 m for SH wave) and 4 m shot distance along the 1.5 km long P-wave and 800 m long SH-wave profiles. A Ricker wavelet and the use of absorbing frames were first-order model parameters. The petrophysical parameters to populate the structural models down to 400 m depth were taken from borehole data, VSP (vertical seismic profile) measurements and cross-plot relations. The simulation of the P-wave wave-field was based on interpretation of the P-wave depth section that included a priori information from boreholes and airborne electromagnetics. Velocities for 14 layers in the model were derived from the analysis of five nearby VSPs (vP =1600-2300 m s-1). Synthetic shot data were compared with the field data and seismic sections were created. Major features like direct wave and reflections are imaged. We reproduce the mayor reflectors in the depth section of the field data, e.g. a prominent till layer and several deep reflectors. The SH-wave model was adapted accordingly but only led to minor correlation with the field data and produced a higher signal-to-noise ratio. Therefore, we suggest to consider for future simulations additional features like intrinsic damping, thin layering, or a near-surface weathering layer. These may lead to a better understanding of key parameters determining the data quality of near-surface shear-wave seismic measurements. 18. Queueing-blocking system with two arrival streams and guard channels Microsoft Academic Search ROCH GUERIN 1988-01-01 An approach to the study of a multichannel cutoff priority system for two Poisson arrival streams with distinct arrival rates and the same potential service time distribution is proposed. This approach makes it possible to obtain the state probabilities in simple closed-form expressions. These expressions provide a straightforward way to derive the distribution of the number of busy servers, the 19. Factors Associated with Early Hospital Arrival in Patients with Acute Ischemic Stroke PubMed Central Song, Dongbeom; Tanaka, Eijirou; Lee, Kijeong; Sato, Shoichiro; Koga, Masatoshi; Kim, Young Dae; Nagatsuka, Kazuyuki; Toyoda, Kazunori 2015-01-01 Background and Purpose Factors associated with early arrival may vary according to the characteristics of the hospital. We investigated the factors associated with early hospital arrival in two different stroke centers located in Korea and Japan. Methods Consecutive patients with ischemic stroke arrived hospital within 48 hours of onset between January 2011 and December 2012 were identified and the clinical and time variables were retrieved from the prospective stroke registries of Severance Hospital of Yonsei University Health System (YUHS; Seoul, Korea) and National Cerebral and Cardiovascular Center (NCVC; Osaka, Japan). Subjects were dichotomized into early (time from onset to arrival ?4.5 hours) and late (>4.5 hours) arrival groups. Univariate and multivariate analyses were performed to evaluate factors associated with early hospital arrival. Results A total of 1,966 subjects (992 from YUHS; 974 from NCVC) were included in this study. The median time from onset to arrival was 6.1 hours [interquartile range, 1.7-17.8 hours]. In multivariate analysis, the factors associated with early arrival were atrial fibrillation (Odds ratio [OR], 1.505; 95% confidence interval [CI], [1.168-1.939]), higher initial National Institute of Health Stroke Scale scores (OR, 1.037; 95% CI [1.023-1.051]), onset during daytime (OR, 2.799; 95% CI [2.173-3.605]), and transport by an emergency medical service (OR, 2.127; 95% CI [1.700-2.661]). These factors were consistently associated with early arrival in both hospitals. Conclusions Despite differences between the hospitals, there were common factors related to early arrival. Efforts to identify and modify these factors may promote early hospital arrival and improve stroke outcome. 20. Joint Tomographic Inversion of Body-Wave Arrivals and Gravity Data at the Sacramento-San Joaquin River Delta NASA Astrophysics Data System (ADS) Teel, A.; Thurber, C. H.; Bennington, N. L.; Zhang, H. 2011-12-01 The Sacramento-San Joaquin River Delta (SSJRD) occurs at the confluence of the Sacramento and San Joaquin rivers in the Central Valley of California. The Central Valley is a sedimentary basin that divides the granitic Sierra Nevada range on the east from the heterogeneous Franciscan formation to the west. It is home to a series of levees that control about half of California's annual stream flow, and more than half of Californians get their drinking water from the SSJRD area. Previous studies show that ground motion from magnitude 6.0 earthquakes, which have recurrence intervals of about 100 years in the area, are capable of causing levee failure. While the highest risk for levee failure is in the western SSJRD, since it is near at least five major faults, a medium to high risk of catastrophic levee failure also exists for most of the central SSJRD. These assessments incorporate qualitative estimates of parameters such as basin amplification based on individual knowledge and experience, since geotechnical information is limited in the area. Likewise, two fault models are used in the study, which differ primarily in the assumed presence or absence of a blind thrust fault under the northwest corner of the SSJRD. To improve hazard assessment, particularly in regards to basin amplification of strong ground motion, local tomographic imaging is necessary to determine the shape of the Central Valley at depth and to help evaluate the presence of faults. We will present a new local P-wave velocity model for the SSJRD, determined from joint inversion of seismic arrival times and gravity measurements. For the purposes of this study, gravity data primarily complement body-wave data by providing information on shallow density structure and are more effective at delineating lateral density variations. Seismic waves provide better depth resolution but are limited by the spatial distribution of earthquake and receiver locations. Our datasets comprise over 213,000 (regional and local) arrival times and approximately 5000 local Bouguer-corrected gravity readings. We are developing a version of the seismic tomography code tomoDD, modified to incorporate gravity data. Published empirical relationships between density and seismic velocity will be used to connect the two data types. Current density-velocity relationships are based on rocks from different geologic settings and can not account for non-uniqueness in density and velocity for different rock types. We will strive to implement these density-velocity relationships with depth dependence in order to model them more realistically. 1. Velocity Structure of the Tibetan Lithosphere: Constraints from P-Wave Travel Times of Regional Earthquakes E-print Network Nowack, Robert L. - ing of the Moho depth and a decrease in Pn velocities to the north. The corrected Figure 5 is shown error Shallowing of Moho and decrease in Pn velocities to the north Shallowing of Moho and decrease in Pn velocities to the north Shallowing of Moho and decrease in Pn velocities to the north Shallowing 2. Does Pet Arrival Trigger Prosocial Behaviors in Individuals with Autism? PubMed Central Grandgeorge, Marine; Tordjman, Sylvie; Lazartigues, Alain; Lemonnier, Eric; Deleau, Michel; Hausberger, Martine 2012-01-01 Alteration of social interactions especially prosocial behaviors – an important aspect of development – is one of the characteristics of autistic disorders. Numerous strategies or therapies are used to improve communication skills or at least to reduce social impairments. Animal-assisted therapies are used widely but their relevant benefits have never been scientifically evaluated. In the present study, we evaluated the association between the presence or the arrival of pets in families with an individual with autism and the changes in his or her prosocial behaviors. Of 260 individuals with autism - on the basis of presence or absence of pets - two groups of 12 individuals and two groups of 8 individuals were assigned to: study 1 (pet arrival after age of 5 versus no pet) and study 2 (pet versus no pet), respectively. Evaluation of social impairment was assessed at two time periods using the 36-items ADI-R algorithm and a parental questionnaire about their child-pet relationships. The results showed that 2 of the 36 items changed positively between the age of 4 to 5 (t0) and time of assessment (t1) in the pet arrival group (study 1): “offering to share” and “offering comfort”. Interestingly, these two items reflect prosocial behaviors. There seemed to be no significant changes in any item for the three other groups. The interactions between individuals with autism and their pets were more – qualitatively and quantitatively - reported in the situation of pet arrival than pet presence since birth. These findings open further lines of research on the impact of pet’s presence or arrival in families with an individual with autism. Given the potential ability of individuals with autism to develop prosocial behaviors, related studies are needed to better understand the mechanisms involved in the development of such child-pet relationship. PMID:22870246 3. P-wave morphology during right atrial pacing before and after atrial flutter ablation—A new marker for success Microsoft Academic Search Mohamed H. Hamdan; Jonathan M. Kaiman; Hal V. Barron; Michael D. Lesh 1997-01-01 Simple examination of the surface P wave in the inferior leads when pacing from a location lateral to the subeustachian isthmus might be a substitute for the more cumbersome endocardial mapping needed for demonstration of bidirectional block. 4. P-wave signal-averaged electrocardiogram in patients with idiopathic mitral valve prolapse syndrome and supraventricular arrhythmias Microsoft Academic Search Waldemar Banasiak; Iwona Pajak; Piotr Ponikowski; Wieslaw Lacheta; Krzysztof Wiech; Massimo Piepoli; Czeslaw Telichowski 1995-01-01 The aim of the study was to assess whether the P-wave triggered signal-averaged ECG (SAECG) used in patients with idiopathic mitral valve prolapse syndrome could predict the risk of the development of supraventricular arrhythmias. Fifty patients with idiopathic mitral valve prolapse syndrome (15 men, 35 women, mean age: 37 ± 9 years) were prospectively studied. P-wave triggered SAECG was recorded 5. Induced p-wave superfluidity in strongly interacting imbalanced Fermi gases SciTech Connect Patton, Kelly R.; Sheehy, Daniel E. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States) 2011-05-15 The induced interaction among the majority spin species, due to the presence of the minority species, is computed for the case of a population-imbalanced resonantly interacting Fermi gas. It is shown that this interaction leads to an instability, at low temperatures, of the recently observed polaron Fermi liquid phase of strongly imbalanced Fermi gases to a p-wave superfluid state. We find that the associated transition temperature, while quite small in the weakly interacting BCS regime, is experimentally accessible in the strongly interacting unitary regime. 6. An exactly soluble model with tunable p-wave paired fermion ground states Microsoft Academic Search Yue Yu; Ziqiang Wang 2008-01-01 Motivated by the work of Kitaev, we construct an exactly soluble spin-½ model on a honeycomb lattice whose ground states are identical to Delta1xpx+Delta1ypy+i(Delta2xpx+Delta2ypy)-wave paired fermions on a square lattice, with tunable paring order parameters. We derive a universal phase diagram for this general p-wave theory which contains a gapped A-phase and a topologically non-trivial B-phase. We show that the 7. Entanglement Entropy in Holographic P-Wave Superconductor/Insulator Model E-print Network Rong-Gen Cai; Li Li; Li-Fang Li; Ru-Keng Su 2013-05-27 We continue our study of entanglement entropy in the holographic superconducting phase transitions. In this paper we consider the holographic p-wave superconductor/insulator model, where as the back reaction increases, the transition is changed from second order to first order. We find that unlike the s-wave case, there is no additional first order transition in the superconducting phase. We calculate the entanglement entropy for two strip geometries. One is parallel to the super current, and the other is orthogonal to the super current. In both cases, we find that the entanglement entropy monotonically increases with respect to the chemical potential. 8. Condensates of p-Wave Pairs Are Exact Solutions for Rotating Two-Component Bose Gases SciTech Connect Papenbrock, T [UTK/ORNL/GSI-Darmstadt/Inst. für Kernphysik, Tech. Univ. Darmstadt-Germany; Reimann, S. M. [Lund University, Sweden; Kavoulakis, G. M. [Technological Educational Institute of Crete, Heraklion, Greece 2012-01-01 We derive exact analytical results for the wave functions and energies of harmonically trapped two-component Bose-Einstein condensates with weakly repulsive interactions under rotation. The isospin symmetric wave functions are universal and do not depend on the matrix elements of the two-body interaction. The comparison with the results from numerical diagonalization shows that the ground state and low-lying excitations consist of condensates of p-wave pairs for repulsive contact interactions, Coulomb interactions, and the repulsive interactions between aligned dipoles. 9. P-wave pentaquark and its decay in the quark model with instanton induced interaction SciTech Connect Shinozaki, Tetsuya; Oka, Makoto [Department of Physics, H-27, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan); Takeuchi, Sachiko [Japan College of Social Work, Kiyose 204-8555 (Japan) 2006-09-01 P-wave pentaquarks with strangeness +1, I=0, and J{sup P}=1/2{sup +} are studied in the nonrelativistic quark model with instanton induced interaction (III). We present their mass splittings and orbital-spin-isospin-color structures. It is found that decompositions of the wave functions are sensitive to III, while the mass splittings are insensitive. The decay of the lowest energy pentaquark, {theta}{sup +}, is found to be suppressed when the contribution of III is increased. Spin structure of the dominant components of the wave function is studied. 10. A Split of Direction of Propagation and Attenuation of P Waves in the Po Valley NASA Astrophysics Data System (ADS) Daminelli, R.; Tento, A.; Marcellini, A. 2013-12-01 On July 17, 2011 a ML 4.8 earthquake occurred in the PO valley at a 48 km epicentral distance from a seismic station located at Palazzo Te (Mantova). The station is situated on deep quaternary sediments: the uppermost layers are mainly composed of clay and silty clay with interbedded sands; the Robertson index is 1.4P wave particle motion, that appears rather difficult to explain if we assume the homogeneity of the P waves (that means attenuation is scalar). Note that the degree of nonlinearity is very low given that the maximum strain can be roughly estimated as 10-5 on the basis of maximum ground velocity of the P wave train considered and the Vp. On the contrary we show that P wave particle motion can be fully (and easily) described by a Homogeneous Isotropic Linear Viscoelastic model (HILV). HILV, as in the 2009 Borcherdt formulation adopted here, allows two different directions of propagation and attenuation; in other words attenuation becomes a vector that is not necessarily parallel to the propagation vector. The results evidence that the incidence angle and the inhomogeneity angle (it is the angle between propagation and attenuation vectors and it is closely related to Q factor) are in good agreement with the geological conditions of the site. Finally, we observed that these results are very similar to the ones obtained when we analyzed two explosions recorded by a seismic station in Milano, also situated in the Po valley at some 140 km from Mantova (Marcellini & Tento, 2011). Borcherdt, R.D. (2009) 'Viscoelastic Waves in Layered Media', Cambridge University Press, Cambridge, United Kingdom, 305 pp. Marcellini, A. and A. Tento (2011) ' Explosive Sources Prove the Validity of Homogeneous Isotropic Linear Viscoelastic Models', BSSA, Vol. 101, No. 4, pp. 1576-1583. 11. Local Determination of Weak Anisotropy Parameters from qP-wave Slowness and Particle Motion Measurements Microsoft Academic Search Xuyao Zheng; Ivan Pšen?ík \\u000a We propose an algorithm for local evaluation of weak anisotropy (WA) parameters from measurements of slowness vector components\\u000a and\\/or of particle motions ofqPwaves at individual receivers in a borehole in a multi-azimuthal multiple-source offset VSP experiment. As a byproduct the\\u000a algorithm yields approximate angular variation of qP-wave phase velocity. The formulae are derived under assumption of weak\\u000a but arbitrary anisotropy 12. Multi-object filtering with Poisson arrival-rate measurements NASA Astrophysics Data System (ADS) Clark, Daniel; Nagappa, Sharad 2011-06-01 Recent interest in multi-object filtering has focussed on the problem of discrete-time filtering, where sets of measurements are collected at regular intervals from the sensor. Many sensors do not provide multiple measurements at regular intervals but instead provide single-measurement reports at irregular time-steps. In this paper we study the multi-object filtering problem for estimation from measurements where the target and clutter processes provide measurements with Poisson arrival rates. In particular, we show that the Probability Hypothesis Density (PHD) filter can be adapted to Poisson arrival rate measurements by modelling the probability of detection with an exponential distribution. We demonstrate the approach in simulated scenarios. 13. Research Of Airborne Precision Spacing to Improve Airport Arrival Operations NASA Technical Reports Server (NTRS) Barmore, Bryan E.; Baxley, Brian T.; Murdoch, Jennifer L. 2011-01-01 In September 2004, the European Organization for the Safety of Air Navigation (EUROCONTROL) and the United States Federal Aviation Administration (FAA) signed a Memorandum of Cooperation to mutually develop, modify, test, and evaluate systems, procedures, facilities, and devices to meet the need for safe and efficient air navigation and air traffic control in the future. In the United States and Europe, these efforts are defined within the architectures of the Next Generation Air Transportation System (NextGen) Program and Single European Sky Air Traffic Management Research (SESAR) Program respectively. Both programs have identified Airborne Spacing as a critical component, with Automatic Dependent Surveillance Broadcast (ADS-B) as a key enabler. Increased interest in reducing airport community noise and the escalating cost of aviation fuel has led to the use of Continuous Descent Arrival (CDA) procedures to reduce noise, emissions, and fuel usage compared to current procedures. To provide these operational enhancements, arrival flight paths into terminal areas are planned around continuous vertical descents that are closer to an optimum trajectory than those in use today. The profiles are designed to be near-idle descents from cruise altitude to the Final Approach Fix (FAF) and are typically without any level segments. By staying higher and faster than conventional arrivals, CDAs also save flight time for the aircraft operator. The drawback is that the variation of optimized trajectories for different types and weights of aircraft requires the Air Traffic Controller to provide more airspace around an aircraft on a CDA than on a conventional arrival procedure. This additional space decreases the throughput rate of the destination airport. Airborne self-spacing concepts have been developed to increase the throughput at high-demand airports by managing the inter-arrival spacing to be more precise and consistent using on-board guidance. It has been proposed that the additional space needed around an aircraft performing a CDA could be reduced or eliminated when using airborne spacing techniques. 14. Any P-wave kinematic algorithm for vertical transversely isotropic media can be ADAPTed to moderately anisotropic media of arbitrary symmetry type NASA Astrophysics Data System (ADS) Rasolofosaon, Patrick N. J. 2003-12-01 Most of P-wave anisotropic kinematic algorithms (modeling, processing, and inversion) have been developed for the case of Transverse Isotropy (TI). Does it mean that when dealing with more complex symmetry types (Arbitrarily tilted TI, orthorhombic, monoclinic or even triclinic), all these algorithms are irrelevant? In fact, not at all. It has recently been demonstrated that in 2D geometry any qP-wave TI kinematic algorithm can be simply generalized to the case of monoclinic symmetry using the so-called Azimuthally Dependent Anisotropy Parameter Transformation (ADAPT), assuming moderate anisotropy. The extension of the technique to the case of arbitrary anisotropy type (triclinic) is achieved in this paper. The method is successfully checked for seismic modeling in a full 2D model with layers of contrasted anisotropy types and with arbitrary vertical and horizontal velocity variations (non-constant gradient). Typically, the approximate travel times using ADAPT differ from the exact travel times by a few milliseconds for total travel times of the order of a few seconds. Applications to seismic processing are also described. The simplicity of the procedure and the generality of the applicability of the ADAPT recipe are striking and very convenient for practical applications. They certainly deserve further analysis. 15. Selection and evolutionary potential of spring arrival phenology in males and females of a migratory songbird. PubMed Tarka, M; Hansson, B; Hasselquist, D 2015-05-01 The timing of annual life-history events affects survival and reproduction of all organisms. A changing environment can perturb phenological adaptations and an important question is if populations can evolve fast enough to track the environmental changes. Yet, little is known about selection and evolutionary potential of traits determining the timing of crucial annual events. Migratory species, which travel between different climatic regions, are particularly affected by global environmental changes. To increase our understanding of evolutionary potential and selection of timing traits, we investigated the quantitative genetics of arrival date at the breeding ground using a multigenerational pedigree of a natural great reed warbler (Acrocephalus arundinaceus) population. We found significant heritability of 16.4% for arrival date and directional selection for earlier arrival in both sexes acting through reproductive success, but not through lifespan. Mean arrival date advanced with 6 days over 20 years, which is in exact accordance with our predicted evolutionary response based on the breeder's equation. However, this phenotypic change is unlikely to be caused by microevolution, because selection seems mainly to act on the nongenetic component of the trait. Furthermore, demographical changes could also not account for the advancing arrival date. Instead, a strong correlation between spring temperatures and population mean arrival date suggests that phenotypic plasticity best explains the advancement of arrival date in our study population. Our study dissects the evolutionary and environmental forces that shape timing traits and thereby increases knowledge of how populations cope with rapidly changing environments. PMID:25847825 16. P-wave Velocity, Density, and Vertical Stress Magnitude Along the Crustal Po Plain (Northern Italy) from Sonic Log Drilling Data NASA Astrophysics Data System (ADS) Montone, Paola; Mariucci, Maria Teresa 2015-06-01 In order to characterize better P-wave velocities for the shallow crust of the Po Plain and surrounding regions, we have selected 64 deep wells mainly located in the plain and also along the Apennine belt and Adriatic coast. In particular, we have analyzed the stratigraphic profiles for all wells, and the available sonic logs (37 out of 64). From these data we have examined the P-wave velocity trend with depth and estimated rock density following an empirical relationship between sonic velocity and density in sedimentary rocks. Then we have calculated, notably, for the first time in a large area of Italy, the overburden stress magnitude for each well. For instance, at a depth of 5 km we have found values varying from 105 to 130 MPa moving from the Adriatic coast to the Apennine belt. Consequently, the Apennine belt shows a maximum regional lithostatic gradient of around 26 MPa/km while the Po Plain and Adriatic region have values of around 21 MPa/km. The maximum density value that can be considered for the Apennine crustal belt corresponds to 2.65 g/cm3; in the Po Plain the mean density is around 2.25 g/cm3, while in the Adriatic area the average density has the lowest value in the region at 2.13 g/cm3. Although in this area a 2D crustal P-wave velocity model does not adequately constrain the complicated and uneven tectonics, we have nevertheless established a shallow model consisting of five separate layers. The strength of this paper lies in the possible use of these direct data, together with other derived geological and geophysical information, to build a 3D model of the area. 17. Collective modes of p-wave superfluid Fermi gases in BEC phase E-print Network Matera, Francesco 2015-01-01 The low-energy modes of a superfluid atomic Fermi gas at zero temperature are investigated. The Bose-Einstein-condensate (BEC) side of the superfluid phase is studied in detail. The atoms are assumed to be in only one internal state, so that for a sufficiently diluted gas the pairing of fermions can be considered effective in the l=1 channel only. In agreement with previous works on p-wave superfluidity in Fermi systems, it is found that thep_x+ip_y$phase represents the lowest energy state in both the Bardeen-Cooper-Schrieffer (BCS) and BEC sides. Our calculations show that at low energy three branches of collective modes can emerge, with different species of dispersion relations: a phonon-like mode, a single-particle-like mode and a gapped mode. A comparison with the Bogoliubov excitations of the corresponding spinor Bose condensate is made. They reproduce the dispersion relations of the excitation modes of the p-wave superfluid Fermi gas to a high accuracy. 18. The effect of diabetic autonomic neuropathy on P-wave duration, dispersion and atrial fibrillation PubMed Central Bissinger, Andrzej; Grycewicz, Tomasz; Grabowicz, Wlodzimierz; Lubinski, Andrzej 2011-01-01 Introduction Atrial fibrillation (AF) is the most common sustained arrhythmia. Diabetic autonomic neuropathy (DAN) is a frequent complication of diabetes mellitus and has a negative impact on the cardiovascular system. There are no data about the occurrence of paroxysmal atrial fibrillation (PAF) in the population with DAN. Material and methods We analysed the data of 100 patients with PAF. The study population was divided into three groups: group I: 28 patients with diabetes mellitus (DM) and DAN, group II: 34 patients with DM without DAN, and group III: 38 patients without DM. P-wave duration (FPD) and dispersion (PWD) were measured during sinus rhythm and AF episodes were counted during 12 months of follow-up. Results Recurrence of PAF was higher in group I (47 episodes/year) compared to groups II and III (26 and 22 episodes/year) – p<0.01. The FPD was longer in group I (137.4 ±12.0 ms vs. 126 ±23.0 ms in II group and 129 ±18.3 ms in group III; p<0.001). The PWD was longer in patients with DAN (53 ±19 ms vs. 36 ±18 ms and 34 ± 20 ms, p<0.001). Conclusions The results showed that the presence of DAN caused a significant increase in P-wave duration and dispersion, which might be responsible for the recurrence of AF. PMID:22291825 19. Preliminary Results for Crustal Structure in Southeastern Africa from P-wave Receiver Functions NASA Astrophysics Data System (ADS) Kachingwe, M.; Nyblade, A.; Mulibo, G. D.; Mulowezi, A.; Kunkuta, E.; De Magalhães, V.; Wiens, D. A.; Wysession, M. E.; Julia, J. 2013-12-01 The crustal structure of southeastern Africa is investigated by modeling P-wave receiver functions using H-k stacking and joint inversion methods. P-wave receiver functions are analyzed for 29 broadband seismic stations in Zambia, Malawi and Mozambique. Estimates for the Moho depth and Poisson's ratio are determined from H-k stacking, and estimates for the shear wave velocity are determined by the joint inversion of receiver functions and surface wave dispersion. Preliminary results show that Moho depths beneath southeastern Africa range from 32 km to 51 km. Thicker crust is found in Proterozoic terrains, such as the Irumide Belt, while thinner crust is found in reworked Archean terrains, such as the Bangweulu Block. These results are consistent with previous studies and global averages for Precambrian terrains. The preliminary results also show a range of Poisson's ratios from 0.2 to 0.3. These new results for southeastern Africa are being combined with similar results from elsewhere in eastern and southern Africa to improve our understanding of African crustal structure. 20. Preliminary Results for Crustal Structure in Southeastern Africa from P-wave Receiver Functions NASA Astrophysics Data System (ADS) Kachingwe, M.; Nyblade, A.; Mulibo, G.; Mulowezi, A.; Kunkuta, E.; De Magalhães, V.; Wysession, M. E.; Wiens, D. A.; Julia, J. 2012-12-01 The crustal structure of southeastern Africa is investigated by modeling P-wave receiver functions using H-k stacking and joint inversion methods. P-wave receiver functions are analyzed for 29 broadband seismic stations in Zambia, Malawi and Mozambique. Estimates for the Moho depth and Poisson's ratio are determined from H-k stacking, and estimates for the shear wave velocity are determined by the joint inversion of receiver functions and surface wave dispersion. Preliminary results show that Moho depths beneath southeastern Africa range from 32 km to 51 km. Thicker crust is found in Proterozoic terrains, such as the Irumide Belt, while thinner crust is found in reworked Archean terrains, such as the Bangweulu Block. These results are consistent with previous studies and global averages for Precambrian terrains. The preliminary results also show a range of Poisson's ratios from 0.2 to 0.3. These new results for southeastern Africa are being combined with similar results from elsewhere in eastern and southern Africa to improve our understanding of African crustal structure. 1. Amplitude and angle of arrival measurements on a 28.56 GHz Earth-space path NASA Technical Reports Server (NTRS) Devasirvatham, D. M. J.; Hodge, D. B. 1981-01-01 The amplitude and angle of arrival measurements on an Earth-space path using the 28.56 GHz COMSTAR D3 satellite beacon are described. These measurements were made by the Ohio State University ElectroScience Laboratory during the period September 1978 to September 1979. Monthly, quarterly, and annual distributions of attenuation, angle of arrival, and variance of both these parameters are reported. During this period, fades exceeding 29 dB for .00% of the time and angle of arrival fluctuations exceeding .12 degrees for .01% of the time were observed. 2. NASA's SOFIA Arrives in Christchurch, New Zealand, July 14, 2013 - Duration: 101 seconds. NASA Video Gallery NASA's Stratospheric Observatory for Infrared Astronomy airborne observatory arrived at Christchurch International Airport, New Zealand, July 14 at 12:14 p.m. (New Zealand Standard Time) to investi... 3. How do I collect my key on arrival at Lister House? Keys are collected directly from Lister House office, but please read the separate arrival E-print Network Glasgow, University of available) The email address is [email protected] What are the Office opening hours? The Lister House Office time and do need to know your date and time of arrival in advance. How close is the Lister House as the office is only open part time and there is not always someone available to show you round. #12;What do I 4. [Getting qi and arrival of qi]. PubMed Liu, Nong-Yu 2014-08-01 In order to clarify the inter-relationship between getting qi and arrival of qi, the relevant theory in the Inner Canon of Yellow Emperor is re-considered, and then the relationship of the two concepts by combining with some opinions from scholars is compared and analyzed. Getting qi is the signal of acupuncture at an acupoint; also it is a sign of arrival of qi at an acupoint; what's more, it is the premise for reinforcing or reducing manipulation. The sensation of arrival of qi comes from both doctors and patients, characterized with explicit symptoms including "tight and swift", "sunken, sticky and tight", "light, loose and slow", "warm at the acupoint" or "cold at the acupoint" as well as implicit symptom including "qi moving along the meridians"; also there is the condition of qi regulation that is characterized with "paced and harmony" stomach qi. The arrival of qi could be divided into "qi moving to the needles" and "qi traveling to the diseases". The "qi moving to the needles" has similar meaning to getting qi. The "qi traveling to the diseases" is reflected as "qi arrival with efficacy" and characterized as an immediate effect or a delayed effect. There are differences between the concepts of getting qi and arrival of qi. Getting qi focuses on the importance of the doctor during acupuncture processes (differentiate the nature of qi, guard qi, manipulate qi), which also suggests the clinical significance of implicit getting qi. "Arrival of qi" emphasizes "qi arrival with efficacy", and indicates that during treatment the differences of the exterior or interior and deficit or surplus should be distinguished. For external and shallow diseases involving myofascia-related diseases, miu needling and shallow needling can achieve an immediate treatment effect; for deep, internal and deficient diseases, reinforcing or reducing manipulation should be used to achieve stomach qi, which has delayed effects but can be used as an indicator. It is believed that pulse diagnosis shall not be neglected in clinical treatment of acupuncture. PMID:25335272 5. Effects of p-wave annihilation on the angular power spectrum of extragalactic gamma-rays from dark matter annihilation SciTech Connect Campbell, Sheldon; Dutta, Bhaskar [Department of Physics and Astronomy, Texas A and M University, College Station, Texas 77843 (United States) 2011-10-01 We present a formalism for estimating the angular power spectrum of extragalactic gamma-rays produced by dark matter annihilating with any general velocity-dependent cross section. The relevant density and velocity distribution of dark matter is modeled as an ensemble of smooth, universal, rigid, disjoint, spherical halos with distribution and universal properties constrained by simulation data. We apply this formalism to theories of dark matter with p-wave annihilation, for which the relative-velocity-weighted annihilation cross section is {sigma}v=a+bv{sup 2}. We determine that this significantly increases the gamma-ray power if b/a > or approx. 10{sup 6}. The effect of p-wave annihilation on the angular power spectrum is very similar for the sample of particle physics models we explored, suggesting that the important effect for a given b/a is largely determined by the cosmic dark matter distribution. If the dark matter relic from strong p-wave theories is thermally produced, the intensities of annihilation gamma-rays are strongly p-wave suppressed, making them difficult to observe. If an angular power spectrum consistent with a strong p wave were to be observed, it would likely indicate nonthermal production of dark matter in the early Universe. 6. Effects of exciting frequencies, grain sizes, and damage upon P-wave velocity for ultrasonic NDT of concrete NASA Astrophysics Data System (ADS) Ju, Jiann W.; Weng, Lisheng 2000-05-01 This paper focuses on the experimental study of the effects of exciting frequencies, grain (aggregate) sizes, and damage upon the ultrasonic P-wave velocity when performing the ultrasonic nondestructive testing (NDT) for concrete specimens. Two batches of concrete and mortar specimens were prepared in the laboratory for the investigation of the effects from the stated factors upon the P-wave velocity. Damage here mostly refers to microcracks and microvoids in concrete. Five different aggregate sizes, 0' (mortar), 3/8', 1/2', 3/4', and 1', were selected to demonstrate the grain (aggregate) size effect. Exciting frequencies of the ultrasonic wave were set to range from 100 kHz to 1,000 kHz, with increment of 50 kHz, to demonstrate the frequency effect. Styrofoam particles were mixed into the comparison concrete and mortar specimens to simulate the distributed microvoids (damage). Different volume fractions of styrofoam particles were mixed into the mortar specimens in order to study the effect of different porosities (damage) upon the P-wave velocity. The experimental observations show that, for mortar and concrete specimens with aggregate sizes from 0 to 1 inch, the P-wave velocity would not be affected significantly within the tested frequency range (100 - 1000 kHz). The normalized P-wave velocity exhibits almost identical pattern upon the exciting frequencies for all specimens. 7. Modeling Biot's Coefficient for High Porosity Sediments From P Wave Velocity and Density Data. NASA Astrophysics Data System (ADS) Fabricius, I. L. 2006-12-01 The effective stress coefficient predicts to which extent the fluid pressure in a given sediment counteracts the load of overlying sediments. When monitoring changes in fluid pressure and fluid composition from seismic data, the effective stress coefficient may be approximated by Biot's coefficient, ?. ? is under assumption of hydrostatic stress and linear elasticity defined as: ? = 1 - Kdry/Kmin where Kdry is bulk modulus of the dry sediment and Kmin is the mineral bulk modulus. In heavily cemented sedimentary rocks ? is close to porosity. In lightly cemented sediments Biot's coefficient is close to one and the effective stress, ?' is then predicted from Terzaghi's law: ?' = ? - U where ? is the stress due to the total load of the overburden and U is pore pressure. When ? is taken into account we get the equivalent expression: ?' = ? - ? U For calculation of ? we need information on Kdry. It may be calculated from density, ?dry, P wave velocity vP-dry and shear velocity vS-dry for the dry sediment: Kdry = ?dry (vP-dry2 - 4/3 vS-dry2) In many cases only wet density and P wave velocity are known, and then a possibility is to use Castagna's relations for predicting wet shear wave velocity and then using Gassmann's equations to predict the sonic velocities of the dry sediment. An alternative, which also works outside the range of Castagna's relations is to calculate the isoframe value from wet density and wet P-wave velocity and then use the isoframe value to model Kdry. The isoframe value, IF, is derived from a Hashin-Shtrikman model: K = ((? + (1-IF)(1-?))/(Ksus + 4/3Gmin) + (IF(1-?))/(Kmin + 4/3Gmin))-1 - 4/3Gmin G = ((? + (1-IF)(1-?))/? + (IF(1-?))/(Gmin + ?))-1 - ? ? = Gmin/6 ((9Kmin + 8 Gmin)/(Kmin + 2Gmin)) M = K + 4/3G = ? vP2 Where: K is bulk modulus, G is shear modulus, ? is porosity, Gmin is mineral shear modulus, Kfluid is bulk modulus of pore fluid, Kair is bulk modulus of air, and where for wet sediments: Ksus = (?/Kfluid + ((1-?)(1-IF))/ Kmin)-1 and for dry sediments: Ksus = Kair 8. Effect of cracks on the pressure dependence of P wave velocities in crystalline rocks NASA Astrophysics Data System (ADS) Carlson, Richard L.; Gangi, Anthony F. 1985-09-01 To test the "bed of nails" model, we have made detailed measurements of P wave velocities in five low-porosity, crystalline rocks at effective pressures to 500 MPa and fit two equations based on the model to the laboratory data. The first equation, V(P) = V0(1 + P/ Pi)(1 - m)/2, applies at relatively low pressures because it assumes that the grain modulus is very much larger than the crack modulus. It can be fit to four of the five data sets. The fit to the data for a monomineralic epidote yields values for V0, Piand m of 8.02±0.02 km/s, 1.2±0.5 MPa, and 0.9845±0.0004, respectively, with a rms error of 6.28 m/s. The second equation, 1/V2 (P) = (1/Vc2 - Vg2)/(1 + P/Pi)1 - m + 1/Vg2 assigns a constant velocity to the grains and applies when the modulus of the cracks is of the order of the grain modulus at high pressures. This equation can be fit to three of the data sets; the fit to data for a diopside pyroxenite yields values of Vc, Vg, Pi, and m of 6.20±0.04 km/s, 8.28±0.02 km/s, 7±1 MPa, and 0.20±0.05, with a rms error of 17.9 m/s. For all seven fits to the laboratory data the rms errors range from 0.1 to 0.3% and are of the order of the limits of precision of the measurements. The "bed of nails" model explains the pressure dependence of P wave velocities in the samples remarkably well, as evidenced by the small rms errors. The variation with pressure of P wave velocities in these rocks clearly reflects the increasing stiffness of cracks. The fact that the first equation fits four of five data sets is one of several indications that cracks significantly affect the mechanical properties of the rocks even at 500 MPa. Finally, we note that different kinds of cracks have markedly different mechanical properties; the best fitting model parameters reflect the nature of the cracks which populate the samples. 9. Holographic phase transitions of p-wave superconductors in Gauss-Bonnet gravity with backreaction SciTech Connect Cai Ronggen; Nie Zhangyu; Zhang Haiqing [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China) 2011-03-15 We investigate the phase transitions of holographic p-wave superconductors in (4+1)-dimensional Einstein-Yang-Mills-Gauss-Bonnet theories, in a grand canonical ensemble. Turning on the backreaction of the Yang-Mills field, it is found that the condensations of vector order parameter become harder if the Gauss-Bonnet coefficient grows up or the backreaction becomes stronger. In particular, the vector order parameter exhibits the features of first order and second order phase transitions, while only the second order phase transition is observed in the probe limit. We discuss the roles that the Gauss-Bonnet term and the backreaction play in changing the order of phase transition. 10. Spin polarization and Zeeman effects in ferromagnet/ferromagnetic p-wave superconductor junctions NASA Astrophysics Data System (ADS) Li, Hong; Yang, Xinjian 2011-01-01 An extended Blonder-Tinkham-Klapwijk (BTK) approach is applied to study the spin polarization and Zeeman effects in ferromagnet/ferromagnetic p-wave superconductor ( FM/FpS) junctions. Three kinds of pairings for F pS are chosen: px,py,px+ipy waves. It is found that the normalized conductance strongly depends on both kinds of pairings and the relative orientations of the effective exchange field in the FM and FpS. In triplet superconductor junctions the multiplication of zero-energy Andreev bound states (ABSs) with the Zeeman effect induces an additional peak splitting. This property may serve as a method to identify triplet symmetry of ferromagnetic superconductors. 11. Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography NASA Astrophysics Data System (ADS) Berk Biryol, C.; Beck, Susan L.; Zandt, George; Özacar, A. Arda 2011-03-01 Lithospheric deformation throughout Anatolia, a part of the Alpine-Himalayan orogenic belt, is controlled mainly by collision-related tectonic escape of the Anatolian Plate and subduction roll-back along the Aegean Subduction Zone. We study the deeper lithosphere and mantle structure of Anatolia using teleseismic, finite-frequency, P-wave traveltime tomography. We use data from several temporary and permanent seismic networks deployed in the region. Approximately 34 000 P-wave relative traveltime residuals, measured in multiple frequency bands, are inverted using approximate finite-frequency sensitivity kernels. Our tomograms reveal segmented fast seismic anomalies beneath Anatolia that corresponds to the subducted portion of the African lithosphere along the Cyprean and the Aegean trenches. We identify these anomalies as the subducted Aegean and the Cyprus slabs that are separated from each other by a gap as wide as 300 km beneath Western Anatolia. This gap is occupied by slow velocity perturbations that we interpret as hot upwelling asthenosphere. The eastern termination of the subducting African lithosphere is located near the transition from central Anatolia to the Eastern Anatolian Plateau or Arabian-Eurasian collision front that is underlain by large volumes of hot, underplating asthenosphere marked by slow velocity perturbations. Our tomograms also show fast velocity perturbations at shallow depths beneath northwestern Anatolia that sharply terminates towards the south at the North Anatolian Fault Zone (NAFZ). The associated velocity contrast across the NAFZ persists down to a depth of 100-150 km. Hence, our study is the first to investigate and interpret the vertical extent of deformation along this nascent transform plate boundary. Overall, the resolved upper-mantle structure of Anatolia is directly related with the geology and tectonic features observed at the surface of the Anatolian Plate and suggest that the segmented nature of the subducted African lithosphere plays an important role in the evolution of Anatolia and distribution of its tectonic provinces. 12. Formation and propagation of Love waves from a P-wave source NASA Astrophysics Data System (ADS) Florence, A. L.; Miller, S. A.; Kirkpatrick, S. W. 1992-01-01 The objective of this research is to experimentally investigate and support, by finite element calculations, the formation and propagation of Love waves from a P-wave source due to scattering at material heterogeneities. A series of experiments were conducted where surface strains were measured parallel and perpendicular to a planar granite scattering surface. The granite wall that is cast in a surface layer waveguide of a low-impedance grout and then cast on a granite base provided the interface for generating horizontally polarized (SH) waves in the surface layer. The in-plane shear waves are the Love waves we measured at the surface. The P-wave source was a 1-cm-diameter spherical explosive of PETN diluted with microballoons to provide a charge density of 0.45 g/cm cast in a styrofoam sphere to further attenuate the peak pressure. We successfully measured the strains at three locations parallel to the wall and two locations perpendicular to the wall, and the test repeatability was good. Good agreement was also observed between the measured and calculated strain at all locations. The code calculations also showed that in-plane shear strains form along the surface layer/granite interface, and these shear strains propagate with little reduction in amplitude but transform relatively high-frequency oscillations to low-frequency wave packets. The experimental configuration used to generate and measure Love waves, an evaluation of the source used in the surface layer experiments, and results from finite element code calculations of the experiment are presented. 13. BeforeYou Arrive . . . Plan Ahead E-print Network Mathis, Wayne N. Invertebrates · TheScientistIsIn Favorites Activities Favorites #12;New Discoveries for Kids Can you guess where IBeforeYou Arrive . . . Plan Ahead Learn what exciting activities and exhibitions may be available Things Fly, American Indian Museum's imagiNATIONS Activity Center, Natural History Museum's Q?rius (check 14. While at Paranal Arrival at Reception (Logistics) E-print Network Liske, Jochen While at Paranal Arrival at Reception (Logistics) Meals General Health Recommendations Safety member and most of their belongings are stored in the closets and/or room. Logistics can provide youLockers in the Control Building and base camp as well as a safe in the Logistics office are available to store your 15. Wake Turbulence Mitigation for Arrivals (WTMA) NASA Technical Reports Server (NTRS) Williams, Daniel M.; Lohr, Gary W.; Trujillo, Anna C. 2008-01-01 The preliminary Wake Turbulence Mitigation for Arrivals (WTMA) concept of operations is described in this paper. The WTMA concept provides further detail to work initiated by the Wake Vortex Avoidance System Concept Evaluation Team and is an evolution of the Wake Turbulence Mitigation for Departure concept. Anticipated benefits about reducing wake turbulence separation standards in crosswind conditions, and candidate WTMA system considerations are discussed. 16. Before you arrive Complete your offer E-print Network Evans, Paul of your passport and visa. Visit www.ntu.ac.uk/enrol to find out more. Collect your student ID card You sure you pack a jacket or jumper. There are many shops in Nottingham to buy clothing for the winter you arrive Settle into your accommodation Find out where your local supermarket is and buy some food 17. Research Article Forecasting hotel arrivals and occupancy E-print Network Atiya, Amir A U TH O R C O PY Research Article Forecasting hotel arrivals and occupancy using Monte Carlo-Shishinyc and Neamat E. Gayara a Department of Information Technology, Faculty of Computers and Information, Cairo Advanced Technology and Center for Advanced Studies at IBM Technology Development Center, Cairo, Egypt 18. New Accessions Arriving at Field Records USGS Multimedia Gallery Materials arrive from across the country to be accessioned and processed at the Denver Library, Field Records Collection. Geologic Discipline scientists are encouraged to deposit their project materials and with the Field Records Collection. Materials in the collection are managed as Federal records... 19. Energy Harvesting Communications with Continuous Energy Arrivals E-print Network Yener, Aylin Energy Harvesting Communications with Continuous Energy Arrivals Burak Varan Kaya Tutuncuoglu Aylin--This work considers an energy harvesting transmit- ter that gathers a continuous flow of energy from intermittent sources, thus relaxing the modeling assumption of discrete amounts of harvested energy present 20. NASA's ATM Technology Demonstration-1: Integrated Concept of Arrival Operations NASA Technical Reports Server (NTRS) Baxley, Brian T.; Swenson, Harry N.; Prevot, Thomas; Callantine, Todd J. 2012-01-01 This paper describes operations and procedures envisioned for NASA s Air Traffic Management (ATM) Technology Demonstration #1 (ATD-1). The ATD-1 Concept of Operations (ConOps) demonstration will integrate three NASA technologies to achieve high throughput, fuel-efficient arrival operations into busy terminal airspace. They are Traffic Management Advisor with Terminal Metering (TMA-TM) for precise time-based schedules to the runway and points within the terminal area, Controller-Managed Spacing (CMS) decision support tools for terminal controllers to better manage aircraft delay using speed control, and Flight deck Interval Management (FIM) avionics and flight crew procedures to conduct airborne spacing operations. The ATD-1 concept provides de-conflicted and efficient operations of multiple arrival streams of aircraft, passing through multiple merge points, from top-of-descent (TOD) to touchdown. It also enables aircraft to conduct Optimized Profile Descents (OPDs) from en route altitude to the runway, using primarily speed control to maintain separation and schedule. The ATD-1 project is currently addressing the challenges of integrating the three technologies, and implantation into an operational environment. Goals of the ATD-1 demonstration include increasing the throughput of high-density airports, reducing controller workload, increasing efficiency of arrival operations and the frequency of trajectory-based operations, and promoting aircraft ADS-B equipage. 1. The relationship between gas hydrate saturation and P-wave velocity of pressure cores obtained in the Eastern Nankai Trough NASA Astrophysics Data System (ADS) Konno, Y.; Yoneda, J.; Jin, Y.; Kida, M.; Suzuki, K.; Nakatsuka, Y.; Fujii, T.; Nagao, J. 2014-12-01 P-wave velocity is an important parameter to estimate gas hydrate saturation in sediments. In this study, the relationship between gas hydrate saturation and P-wave velocity have been analyzed using natural hydrate-bearing-sediments obtained in the Eastern Nankai Trough, Japan. The sediment samples were collected by the Hybrid Pressure Coring System developed by Japan Agency for Marine-Earth Science and Technology during June-July 2012, aboard the deep sea drilling vessel CHIKYU. P-wave velocity was measured on board by the Pressure Core Analysis and Transfer System developed by Geotek Ltd. The samples were maintained at a near in-situ pressure condition during coring and measurement. After the measurement, the samples were stored core storage chambers and transported to MHRC under pressure. The samples were manipulated and cut by the Pressure-core Non-destructive Analysis Tools or PNATs developed by MHRC. The cutting sections were determined on the basis of P-wave velocity and visual observations through an acrylic window equipped in the PNATs. The cut samples were depressurized to measure gas volume for saturation calculations. It was found that P-wave velocity correlates well with hydrate saturation and can be reproduced by the hydrate frame component model. Using pressure cores and pressure core analysis technology, nondestructive and near in-situ correlation between gas hydrate saturation and P-wave velocity can be obtained. This study was supported by funding from the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) planned by the Ministry of Economy, Trade and Industry (METI), Japan. 2. Does the arrival index predict physiological stress reactivity in children. PubMed de Veld, Danielle M J; Riksen-Walraven, J Marianne; de Weerth, Carolina 2014-09-01 Knowledge about children's stress reactivity and its correlates is mostly based on one stress task, making it hard to assess the generalizability of the results. The development of an additional stress paradigm for children, that also limits stress exposure and test time, could greatly advance this field of research. Research in adults may provide a starting point for the development of such an additional stress paradigm, as changes in salivary cortisol and alpha-amylase (sAA) over a 1-h pre-stress period in the laboratory correlated strongly with subsequent reactivity to stress task (Balodis et?al., 2010, Psychoneuroendocrinology 35:1363-73). The present study examined whether such strong correlations could be replicated in 9- to 11-year-old children. Cortisol and sAA samples were collected from 158 children (83 girls) during a 2.5-h visit to the laboratory. This visit included a 1-h pre-stress period in which children performed some non-stressful tasks and relaxed before taking part in a psychosocial stress task (TSST-C). A higher cortisol arrival index was significantly and weakly correlated with a higher AUCg but unrelated to cortisol reactivity to the stressor. A higher sAA arrival index was significantly and moderately related to lower stress reactivity and to a lower AUCi. Children's personality and emotion regulation variables were unrelated to the cortisol and sAA arrival indices. The results of this study do not provide a basis for the development of an additional stress paradigm for children. Further replications in children and adults are needed to clarify the potential meaning of an arrival index. PMID:24930802 3. Seismological Research Letters Volume 83, Number 1 January/February 2012 103doi: 10.1785/gssrl.83.1.103 Testing a P-Wave Earthquake Early Warning E-print Network Wu, Yih-Min .1.103 Testing a P-Wave Earthquake Early Warning System by Simulating the 1999 Chi-Chi, Taiwan, Mw 7.6 Earthquake Da-Yi Chen, Ting-Li Lin, Yih-Min Wu, and Nai-Chi Hsiao Da-Yi Chen,1,2 Ting-Li Lin,1,3 Yih-Min Wu,1 and hence reduce the blind zone without timely warning, the initial part of the -wave (usually three seconds 4. Spring arrival response to climate change in birds: a case study from eastern Europe Microsoft Academic Search Mecislovas Zalakevicius; Galina Bartkeviciene; Liutauras Raudonikis; Justinas Janulaitis 2006-01-01 This paper analyses the dependence of the first spring arrival dates of short\\/medium- and long-distance migrant bird species\\u000a on climate warming in eastern Europe. The timing of arrival of the selected species at the observation site correlates with\\u000a the North Atlantic Oscillation (NAO) index, air temperature, atmospheric pressure, precipitation and wind characteristics.\\u000a A positive correlation of fluctuations in winter and 5. CELEBRATION 2000: P-wave velocity models of the Bohemian Massif Microsoft Academic Search P. Hrubcova 2003-01-01 Deep structure of the Bohemian Massif (BM), the largest stable outcrop of Variscan rocks in Central Europe, was studied along two refraction profiles, CEL09 that traverses the whole massif in the NW-SE direction, and CEL10 that extends along its eastern edge almost perpendicularly to CEL09. Good quality recordings with clear first arrivals of crustal and upper mantle phases show apparent 6. Optimal Integration of Departure and Arrivals in Terminal Airspace NASA Technical Reports Server (NTRS) Xue, Min; Zelinski, Shannon Jean 2012-01-01 Coordination of operations with spatially and temporally shared resources such as route segments, fixes, and runways improves the efficiency of terminal airspace management. Problems in this category include scheduling and routing, thus they are normally difficult to solve compared with pure scheduling problems. In order to reduce the computational time, a fast time algorithm formulation using a non-dominated sorting genetic algorithm (NSGA) was introduced in this work and applied to a test case based on existing literature. The experiment showed that new method can solve the whole problem in fast time instead of solving sub-problems sequentially with a window technique. The results showed a 60% or 406 second delay reduction was achieved by sharing departure fixes (more details on the comparison with MILP results will be presented in the final paper). Furthermore, the NSGA algorithm was applied to a problem in LAX terminal airspace, where interactions between 28% of LAX arrivals and 10% of LAX departures are resolved by spatial segregation, which may introduce unnecessary delays. In this work, spatial segregation, temporal segregation, and hybrid segregation were formulated using the new algorithm. Results showed that spatial and temporal segregation approaches achieved similar delay. Hybrid segregation introduced much less delay than the other two approaches. For a total of 9 interacting departures and arrivals, delay reduction varied from 4 minutes to 6.4 minutes corresponding flight time uncertainty from 0 to 60 seconds. Considering the amount of flights that could be affected, total annual savings with hybrid segregation would be significant. 7. STS-85 Crew Arrival for TCDT NASA Technical Reports Server (NTRS) 1997-01-01 The Space Shuttle Mission STS-85 crew arrives at the Shuttle Landing Facility for their mission's Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. They are (from left): Mission Specialist Stephen K. Robinson; Payload Commander N. Jan Davis; Mission Specialist Robert L. Curbeam; Commander Curtis L. Brown, Jr.; Pilot Kent V. Rominger; and Payload Specialist Bjarni V. Tryggvason. The liftoff for STS-85 is targeted for August 7, 1997. 8. Two-body state with p -wave interaction in a one-dimensional waveguide under transversely anisotropic confinement NASA Astrophysics Data System (ADS) Gao, Tian-You; Peng, Shi-Guo; Jiang, Kaijun 2015-04-01 We theoretically study two atoms with p -wave interaction in a one-dimensional waveguide, investigating how the transverse anisotropy of the confinement affects the two-body state, especially the properties of the resonance. For a bound-state solution, we find there are a total of three two-body bound states due to the richness of the orbital magnetic quantum number of the p -wave interaction, while only one bound state is supported by the s -wave interaction. Two of them become nondegenerate due to the breaking of the rotation symmetry under a transversely anisotropic confinement. For a scattering solution, the effective one-dimensional scattering amplitude and scattering length are derived. We find the position of the p -wave confinement-induced resonance shifts apparently versus the transverse anisotropy. In addition, a two-channel mechanism for the confinement-induced resonance in a one-dimensional waveguide is generalized to the p -wave interaction, which was previously proposed only for the s -wave interaction. All our calculations are based on the parametrization of the 40K-atom experiments and can thus be confirmed in future experiments. 9. Experimental study on monitoring CO2 sequestration by conjoint analysis of the P-wave velocity and amplitude. PubMed Chen, Hao; Yang, Shenglai; Huan, Kangning; Li, Fangfang; Huang, Wei; Zheng, Aiai; Zhang, Xing 2013-09-01 CO2 sequestration has been considered to be one of the most straightforward carbon management strategies for industrial CO2 emission. Monitoring of the CO2 injection process is one of the best ways to make sure the safety storage but is also a major challenge in CO2 geological sequestration. Previous field and laboratory researches have shown that seismic methods are among the most promising monitoring methods because of the obvious reduction in P-wave velocities caused by CO2 injection. However, as CO2 injection continues, the P-wave velocity becomes increasingly insensitive according to the pilot projects when CO2 saturation is higher than 20-40%. Therefore, the conventional seismic method needs improvement or replacement to solve its limitations. In this study, P-wave velocity and amplitude responses to supercritical CO2 injection in brine-saturated core samples from Jilin oilfield were tested using core displacement and an ultrasonic detection integrated system. Results showed that neither the P-wave velocity nor amplitude could simply be used to monitor the CO2 injection process because of the insensitive or nonmonotonous response. Consequently, a new index was established by synthetically considering these two parameters to invert and monitor the CO2 process, which can be thought of as a newer and more effective assessment criterion for the seismic method. PMID:23915233 10. Anisotropy of Electrical Resistivity and P-wave Velocity in Discrete Samples From Nantroseize Expeditions 315 and 316 NASA Astrophysics Data System (ADS) Louis, L.; Henry, P.; Humbert, F.; Knuth, M.; Likos, W.; Scientists, I. 2008-12-01 We present results of electrical conductivity and P-wave velocity measurements in discrete samples processed onboard Chikyu during Nantroseize expeditions 315 and 316 in the Mega Splay fault and Frontal Thrust of the Nankai accretionary prism. Quasi cubes of 20 mm thickness nominally saturated with seawater were measured across the three parallel sets of faces, first for electrical conductivity, then for P-wave velocity. Average properties and their anisotropies appeared to show some sensitivity to both lithological and fault related features. Overall, strong transverse anisotropy due to sedimentary compaction was observed for both properties with minimum electrical conductivity and P-wave velocity along the vertical core axis direction. Within the horizontal plane perpendicular to the core axis, slight anisotropies were also measured, which are likely related to tectonically driven horizontal shortening, affecting noticeably the original compaction fabric. In order to get some structural insight, samples were reoriented in our laboratories using alternative field demagnetization technique and the in-plane (i.e. perpendicular to the core axis) data rotated accordingly. For the P-wave anisotropy, initial cubes were shaped into polyhedrons in order to get even more accurate estimates. These additional measurements allowed for retrieving for each sample the 3 principal values and vectors of the best fitting ellipsoidal function. Resulting stereoplots were then compared with electrical resistivity, magnetic susceptibility (AMS) and structural data. 11. The Moho structure beneath the tension area of the central Tibet by teleseismic P wave receiver functions NASA Astrophysics Data System (ADS) Duan, Yaohui; Tian, Xiaobo; Liang, Xiaofeng; Xu, Tao; Bai, Zhiming; Chen, Yun; Zhang, Xi; Liu, Zhen; Zhu, Gaohua; Wu, Chenglong; Wu, Zhenbo; Li, Wei; Wang, Minling; Guo, Xi; Zhang, Minghui; Zhou, Beibei; Nie, Shitan; Zhou, Xiaopeng; Wei, Zhi; Teng, Jiwen 2015-04-01 The Tibetan Plateau, with a crustal thickness twice of the normal thickness and an average elevation of 5km, is generated by the continental-continental collision between the India and Eurasian plates as well as the subsequent convergence. The central Tibet filled with a large quantity of normal faults and eastward escaped conjugated strike-slip faults which represent the tension function is thought to be a deformation crush zone between the colliding plates. In order to understand the relationship between the deep structure of the plateau and the surface texture evolution and to build the connection of the subduction of the India plate and shallow surface response, we build 53 broadband seismic stations around the Bangong-Nujiang Suture (named SANDWICH). In this paper, we calculate 3851 high signal-to-noise receiver functions of teleseismic P wave from the SANDWICH broad-band waveforms, and obtain the images of Moho structure of 7 profiles using the common conversion points time to depth migration. Our results show that the average crustal thickness of the central Tibet is 60-70km and crustal thickness of the south of the Bangong-Nujiang Suture is thicker than that of the north. Besides, this part of the plateau is divided into several blocks with different crustal thickness by the normal faults, eastward escaped conjugated strike-slip faults and the Bangong-Nujiang Suture despite the surface is flat which implying that there are some relationships between the deep offset and the shallow faults .We also find the negative amplitude in the depth of 20km around, which probably be the interface of the brittle upper crust and the ductile middle crust. Based on the result, we are willing to investigate how the surface faults tension and the deep tension are connected through the ductile middle crust. 12. "Welcome to Sweden...": Newly Arrived Students' Experiences of Pedagogical and Social Provision in Introductory and Regular Classes ERIC Educational Resources Information Center Nilsson, Jenny; Axelsson, Monica 2013-01-01 Education for newly arrived students in Sweden is commonly organised in introductory classes, providing a basis for transition to the mainstream system. Focusing on the hitherto underinvestigated question of how newly arrived students experience the time in and transition between introductory and regular classes, we analyse the social and… 13. Arrival and departure impulsive Delta V determination for precessing Mars parking orbits NASA Technical Reports Server (NTRS) Desai, Prasun N.; Buglia, James J. 1992-01-01 An attempt is made to develop a method for realistic estimation of the initial LEO mass. The method takes into account the actual geometry between the inbound and outbound hyperbolic asymptotes and the parking orbit, along with precession effects caused by the oblateness of Mars, in calculating the arrival and departure Delta V values. Three mission scenarios alternative to the arbitrarily assumed two tangential periapsis burns are described: a tangential periapsis arrival and an in-plane departure; an in-plane arrival and in-plane departure; and a tangential periapsis arrival and a 3D departure. Results obtained by the method under consideration compared well with a trajectory integration code, where the differences in the initial LEO orbit mass were within one percent, for all three cases. The method is considered to be an ideal tool for preliminary mission design, since it reduces the analysis computation time with minimal loss in accuracy. 14. Can learning intelligence outperforms information sharing in supply chain performances - an order arrival prediction perspective Microsoft Academic Search Kune-muh Tsai; Feng-chin Chou; Wen-chen Chen 2007-01-01 To improve competitive advantage and operational performances of supply chains, we implement multi-agent supply chain modeling with learning capability to predict order arrival times that manufacturers can pre-produce to shorten order lead time for downstream customer orders. As order lead time is reduced, bullwhip effect of supply chains would also be minimized. Two kinds of learning agents are embedded in 15. Crustal Structure across the Appalachian Orogen in Pennsylvania from P-wave receiver functions NASA Astrophysics Data System (ADS) Arroyo, G.; Nyblade, A.; Homman, K. 2014-12-01 Crustal structure across the Appalachian Orogen from eastern Ohio to New Jersey is investigated using P-wave receiver functions to estimate Moho depths and crustal Vp/Vs ratios. Data for this study comes from the PASEIS and the USArray Transportable Array. The PASEIS seismic network includes 22 broadband seismic stations throughout Pennsylvania that were in installed in February 2013. Preliminary results from H-K stacking show that Moho depth varies greatly across the Appalachians, ranging from 53 km in northern Pennsylvania to only 32 km just west of the New Jersey border. The thickest crust can be found nearest to Lake Erie, and a relatively thick crust is maintained in northeastern Pennsylvania and along the Pennsylvania-Ohio border. Crustal thickness decreases to the southeast, and a rather sharp decrease can be seen well before the start of the Allegheny Front. Crustal thickness remains relatively uniform between 43 and 45km in the Appalachian Mountains, and decreases to 33-38km in the Piedmont province. Vp/Vs values range from 1.75 to 1.83, with no observable pattern to the variation. 16. An exactly soluble model with tunable p-wave paired fermion ground states NASA Astrophysics Data System (ADS) Yu, Yue; Wang, Ziqiang 2008-12-01 Motivated by the work of Kitaev, we construct an exactly soluble spin-½ model on a honeycomb lattice whose ground states are identical to ?1xpx+?1ypy+i(?2xpx+?2ypy)-wave paired fermions on a square lattice, with tunable paring order parameters. We derive a universal phase diagram for this general p-wave theory which contains a gapped A-phase and a topologically non-trivial B-phase. We show that the gapless condition in the B-phase is governed by a generalized inversion (G-inversion) symmetry under px leftrightarrow (?1y / ?1x)py. The G-inversion symmetric gapless B-phase near the phase boundaries is described by (1+1)-dimensional gapless Majorana fermions in the asymptotic long-wavelength limit, i.e. the c=1/2 conformal field theory. The gapped B-phase has G-inversion symmetry breaking and is the weak pairing phase described by the Moore-Read Pfaffian. We show that in the gapped B-phase, vortex pair excitations are separated from the ground state by a finite energy gap. 17. Annihilation Rate of Heavy 0^{++} P-wave Quarkonium in Relativistic Salpeter Method E-print Network Guo-Li Wang 2007-08-26 Two-photon and two-gluon annihilation rates of P-wave scalar charmonium and bottomonium up to third radial excited states are estimated in the relativistic Salpeter method. We solved the full Salpeter equation with a well defined relativistic wave function and calculated the transition amplitude using the Mandelstam formalism. Our model dependent estimates for the decay widths:$\\Gamma(\\chi_{c0} \\to 2\\gamma)=3.78$keV,$\\Gamma(\\chi'_{c0} \\to 2\\gamma)=3.51$keV,$\\Gamma(\\chi_{b0} \\to 2\\gamma)=48.8$eV and$\\Gamma(\\chi'_{b0} \\to 2\\gamma)=50.3$eV. We also give estimates of total widths by the two-gluon decay rates:$\\Gamma_{tot}(\\chi_{c0})=10.3$MeV,$\\Gamma_{tot}(\\chi'_{c0})=9.61$MeV,$\\Gamma_{tot}(\\chi_{b0})=0.887$MeV and$\\Gamma_{tot}(\\chi'_{b0})=0.914$MeV. 18. Hybrid Theory of P-Wave Electron-Hydrogen Elastic Scattering NASA Technical Reports Server (NTRS) Bhatia, Anand 2012-01-01 We report on a study of electron-hydrogen scattering, using a combination of a modified method of polarized orbitals and the optical potential formalism. The calculation is restricted to P waves in the elastic region, where the correlation functions are of Hylleraas type. It is found that the phase shifts are not significantly affected by the modification of the target function by a method similar to the method of polarized orbitals and they are close to the phase shifts calculated earlier by Bhatia. This indicates that the correlation function is general enough to include the target distortion (polarization) in the presence of the incident electron. The important fact is that in the present calculation, to obtain similar results only 35-term correlation function is needed in the wave function compared to the 220-term wave function required in the above-mentioned previous calculation. Results for the phase shifts, obtained in the present hybrid formalism, are rigorous lower bounds to the exact phase shifts. 19. P-wave velocity in granulites from South India: implications for the continental crust NASA Astrophysics Data System (ADS) Ramachandran, C. 1992-01-01 P-wave velocities ( Vp) were measured in 160 high-grade metamorphic rocks from the South Indian granulite terrain (SGT). The wide variations observed in the Vp of charnockites and gneisses could be due to the complex prograde and retrograde metamorphic histories of the two major rock types of the SGT. The velocity-density relation showed distinct trends for charnockites and gneisses. Initial stages of retrograde metamorphism in charnockites significantly affected their magnetic properties, however, its effect on velocity and density is not diagnostic. Contrasting physical properties on either side of the Palghat-Cauvery (P-C) shear zone lends support for the contention that the P-C shear zone is a major paleosuture. The laboratory mean Vpof the rocks from the northern SGT are comparable with the mid-crustal DSS velocity in the adjacent granite greenstone terrain (GGT), suggesting that the GGT is possibly underlain by a felsic granulite basement. The physical properties of the high-grade metamorphic rocks from SGT are significantly lower than that of the lower crust. The physical properties and tectonic considerations show that the granulites of South India may not be of lower crustal origin and hence not representative of the lower crust, as generally thought. A simplified two-layer crustal model with a predominantly felsic granulite upper crust and a mafic granulite lower crust, is suggested for the SGT. 20. 7 CFR 352.7 - Notice of arrival. Code of Federal Regulations, 2011 CFR 2011-01-01 ... § 352.7 Notice of arrival. Immediately upon arrival of any shipment of plants or plant products (including noxious weeds) subject to this part and covered by a specific permit, the importer shall submit in duplicate through the... 1. 7 CFR 352.7 - Notice of arrival. Code of Federal Regulations, 2014 CFR 2014-01-01 ... § 352.7 Notice of arrival. Immediately upon arrival of any shipment of plants or plant products (including noxious weeds) subject to this part and covered by a specific permit, the importer shall submit in duplicate through the... 2. Measurement of parity-nonconserving rotation of neutron spin in the 0.734-eV p-wave resonance of$^{139}La$E-print Network T. Haseyama; K. Asahi; J. D. Bowman; P. P. J. Delheij; H. Funahashi; S. Ishimoto; G. Jones; A. Masaike; Y. Masuda; Y. Matsuda; K. Morimoto; S. Muto; S. I. Penttilä; V. R. Pomeroy; K. Sakai; E. I. Sharapov; D. A. Smith; V. W. Yuan 2001-11-21 The parity nonconserving spin rotation of neutrons in the 0.734-eV p-wave resonance of$^{139}La$was measured with the neutron transmission method. Two optically polarized$^3He$cells were used before and behind a a 5-cm long$^{139}La$target as a polarizer and an analyzer of neutron spin. The rotation angle was carefully measured by flipping the direction of$^3He$polarization in the polarizer in sequence. The peak-to-peak value of the spin rotation was found to be$ (7.4 \\pm 1.1) \\times 10^{-3} $rad/cm which was consistent with the previous experiments. But the result was statisticallly improved. The s-p mixing model gives the weak matrix element as$xW = (1.71 \\pm 0.25)\$ meV. The value agrees well with the one deduced from the parity-nonconserving longitudinal asymmetry in the same resonance.
3. Tuning p-Wave Interactions in an Ultracold Fermi Gas of Atoms C. A. Regal, C. Ticknor, J. L. Bohn, and D. S. Jin*
E-print Network
Jin, Deborah
for ultra- cold fermionic atoms. For identical fermions the Pauli exclusion principle forbids sTuning p-Wave Interactions in an Ultracold Fermi Gas of Atoms C. A. Regal, C. Ticknor, J. L. Bohn have measured a p-wave Feshbach resonance in a single-component, ultracold Fermi gas of 40K atoms. We
4. Recent Investigations and Findings about the 2d- and 3d- Neutron Strength Functions and the p-wave Scattering Radius
Mughabghab, S. F.
2014-04-01
Comprehensive and detailed investigations were recently undertaken due to the scarcity of available data on the neutron d-wave strength functions and the need to obtain precise average resonance parameters for advanced technologies. This information is derived by fitting available total cross section data from few keV to 14 MeV neutron energy using the least-squares method, where the total cross section is described in terms of the scattering radius R? for various partial waves, the s-, p-, d-, f- and g- neutron strength functions, neutron penetration factors and phase shifts. The present results reveal the following findings: (i) the peak of the 2d strength function is observed for the first time at A=50; (ii) due to nuclear deformation effects, the 3d-peak is depressed producing two peaks located at 152 and 170, similar to the s-wave case; (iii) except for the deformed mass region, a spherical optical model calculation for the d-wave strength function reasonably describes the trend of the present data; (iv) the derived s- and p-wave strength functions and the s-wave scattering radii are in good agreement with those obtained from the resolved energy region, as reported in the Atlas of Neutron Resonances; (v) the d-wave strength functions are however generally discrepant with available data; (vi) several d-wave strength functions are derived here for the first time; (vii) a new finding is that the p-wave scattering radii for 92 nuclei in the mass region 16O-242Pu exhibit minima roughly at A?80 and 230 and maxima at A?50 and 160.
5. 9 CFR 93.706 - Notification of arrival.
Code of Federal Regulations, 2012 CFR
2012-01-01
...CONVEYANCE AND SHIPPING CONTAINERS Miscellaneous Animals § 93.706 Notification of arrival. Upon the arrival of a hedgehog or tenrec at the port of first arrival in the United States, the importer or his or her agent must present the import...
6. 9 CFR 93.706 - Notification of arrival.
Code of Federal Regulations, 2011 CFR
2011-01-01
...CONVEYANCE AND SHIPPING CONTAINERS Miscellaneous Animals § 93.706 Notification of arrival. Upon the arrival of a hedgehog or tenrec at the port of first arrival in the United States, the importer or his or her agent must present the import...
7. 9 CFR 93.706 - Notification of arrival.
Code of Federal Regulations, 2010 CFR
2010-01-01
...CONVEYANCE AND SHIPPING CONTAINERS Miscellaneous Animals § 93.706 Notification of arrival. Upon the arrival of a hedgehog or tenrec at the port of first arrival in the United States, the importer or his or her agent must present the import...
8. 9 CFR 93.706 - Notification of arrival.
Code of Federal Regulations, 2013 CFR
2013-01-01
...CONVEYANCE AND SHIPPING CONTAINERS Miscellaneous Animals § 93.706 Notification of arrival. Upon the arrival of a hedgehog or tenrec at the port of first arrival in the United States, the importer or his or her agent must present the import...
9. 9 CFR 93.706 - Notification of arrival.
Code of Federal Regulations, 2014 CFR
2014-01-01
...CONVEYANCE AND SHIPPING CONTAINERS Miscellaneous Animals § 93.706 Notification of arrival. Upon the arrival of a hedgehog or tenrec at the port of first arrival in the United States, the importer or his or her agent must present the import...
10. Patterns of spring arrival dates differ in two hirundines
Tim Sparks; Piotr Tryjanowski
2007-01-01
We examined the first arrival dates in the UK over a 56 yr period of 2 hirundines, sand martin Riparia riparia and barn swallow Hirundo rustica, in relation to temperatures along migration routes and at destination. Changes in arrival dates have been much greater for sand martin than for barn swallow, and the arrival order of the 2 species now
11. Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume V S-Wave Measurements in Borehole C4996 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.
SciTech Connect
Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh
2007-06-06
Velocity measurements in shallow sediments from ground surface to approximately 370 to 400 feet bgs were collected by Redpath Geophysics using impulsive S- and P-wave seismic sources (Redpath 2007). Measurements below this depth within basalt and sedimentary interbeds were made by UTA between October and December 2006 using the T-Rex vibratory seismic source in each of the three boreholes. Results of these measurements including seismic records, wave-arrival identifications and interpreted velocity profiles are presented in the following six volumes: I. P-Wave Measurements in Borehole C4993 II. P-Wave Measurements in Borehole C4996 III. P-Wave Measurements in Borehole C4997 IV. S-Wave Measurements in Borehole C4993 V. S-Wave Measurements in Borehole C4996 VI. S-Wave Measurements in Borehole C4997 In this volume (V), all S-wave measurements are presented that were performed in Borehole C4996 at the WTP with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver.
12. Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume VI S-Wave Measurements in Borehole C4997 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.
SciTech Connect
Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh
2007-06-06
Velocity measurements in shallow sediments from ground surface to approximately 370 to 400 feet bgs were collected by Redpath Geophysics using impulsive S- and P-wave seismic sources (Redpath 2007). Measurements below this depth within basalt and sedimentary interbeds were made by UTA between October and December 2006 using the T-Rex vibratory seismic source in each of the three boreholes. Results of these measurements including seismic records, wave-arrival identifications and interpreted velocity profiles are presented in the following six volumes: I. P-Wave Measurements in Borehole C4993 II. P-Wave Measurements in Borehole C4996 III. P-Wave Measurements in Borehole C4997 IV. S-Wave Measurements in Borehole C4993 V. S-Wave Measurements in Borehole C4996 VI. S-Wave Measurements in Borehole C4997 In this volume (VI), all S-wave measurements are presented that were performed in Borehole C4997 at the WTP with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver.
13. 'To arrive where we started, and know the place for the first time': Heidegger, phenomenology, the way human beings first appear in the world, and fresh perspectives on the abortion debate.
PubMed
Mumford, James
2013-01-01
Intellectual stalemate in the abortion debate can be traced in part to its being framed as a standoff between religion and secular philosophy. While the former is thought to generate a broadly 'pro-life' position, the latter is associated with more 'pro-choice' thinking. This essay attempts to break free of this framing by criticising the philosophy informing 'pro-choice' positions, but not by resorting immediately to religious arguments but rather by drawing upon a rival philosophical tradition--the movement within twentieth and twenty-first Continental philosophy which was and is phenomenology. A phenomenological approach to human 'emergence', and in particular an application of the framework Heidegger developed in Being and Time (1927), leads to a radical questioning of whether contemporary English-speaking beginning-of-life ethics have adequately taken into account the way human beings come forth in the world. PMID:25109125
14. Three-dimensional P wave velocity model for the San Francisco Bay region, California
USGS Publications Warehouse
Thurber, C.H.; Brocher, T.M.; Zhang, H.; Langenheim, V.E.
2007-01-01
A new three-dimensional P wave velocity model for the greater San Francisco Bay region has been derived using the double-difference seismic tomography method, using data from about 5,500 chemical explosions or air gun blasts and approximately 6,000 earthquakes. The model region covers 140 km NE-SW by 240 km NW-SE, extending from 20 km south of Monterey to Santa Rosa and reaching from the Pacific coast to the edge of the Great Valley. Our model provides the first regional view of a number of basement highs that are imaged in the uppermost few kilometers of the model, and images a number of velocity anomaly lows associated with known Mesozoic and Cenozoic basins in the study area. High velocity (Vp > 6.5 km/s) features at ???15-km depth beneath part of the edge of the Great Valley and along the San Francisco peninsula are interpreted as ophiolite bodies. The relocated earthquakes provide a clear picture of the geometry of the major faults in the region, illuminating fault dips that are generally consistent with previous studies. Ninety-five percent of the earthquakes have depths between 2.3 and 15.2 km, and the corresponding seismic velocities at the hypocenters range from 4.8 km/s (presumably corresponding to Franciscan basement or Mesozoic sedimentary rocks of the Great Valley Sequence) to 6.8 km/s. The top of the seismogenic zone is thus largely controlled by basement depth, but the base of the seismogenic zone is not restricted to seismic velocities of ???6.3 km/s in this region, as had been previously proposed. Copyright 2007 by the American Geophysical Union.
15. SUPRACENTER: Locating fireball terminal bursts in the atmosphere using seismic arrivals
W. N. Edwards; A. R. Hildebrand
2004-01-01
Terminal bursts and fragmentations of meteoritic fireballs in the atmosphere may now be accurately located in four dimensions (three spatial + temporal) using seismic arrival times of their acoustic waves recorded by seismometer, camera, microphone, and\\/or infrasound stations on the ground. A computer program, SUPRACENTER, calculates travel times by ray tracing through realistic atmospheres (that include winds) and locates source
16. Location of high-frequency P wave microseismic noise in the Pacific Ocean using multiple small aperture arrays
Pyle, Moira L.; Koper, Keith D.; Euler, Garrett G.; Burlacu, Relu
2015-04-01
We investigate source locations of P wave microseisms within a narrow frequency band (0.67-1.33 Hz) that is significantly higher than the classic microseism band (~0.05-0.3 Hz). Employing a backprojection method, we analyze data recorded during January 2010 from five International Monitoring System arrays that border the Pacific Ocean. We develop a ranking scheme that allows us to combine beam power from multiple arrays to obtain robust locations of the microseisms. Some individual arrays exhibit a strong regional component, but results from the combination of all arrays show high-frequency P wave energy emanating from the North Pacific basin, in general agreement with previous observations in the double-frequency (DF) microseism band (~0.1-0.3 Hz). This suggests that the North Pacific source of ambient P noise covers a broad range of frequencies and that the wave-wave interaction model is likely valid at shorter periods.
17. Spontaneous internal field around the non-magnetic impurity in spin-triplet p-wave superconductivity
Takigawa, p.-wave superconductivity M.; Ichioka, M.; Kuroki, K.; Tanaka, Y.
2005-11-01
The electronic structure around an impurity in spin triplet p-wave superconductors is investigated by the Bogoliubov-de Gennes theory on a tight-binding model. We calculate the spontaneous current and the local density of states around the impurity and discuss the difference between sin px+i sin py-wave and sin(px+py)-i sin(-px+py)-wave superconducting states.
18. Application of P-wave reflection imaging to unknown bridge foundations and comparison with other non-destructive test methods
Kermani, Behnoud
Proper design of bridge structures requires an appreciation for the possible failure mechanisms that can develop over the lifetime of the bridge, many of which are related to natural hazards. For example, scour is one of the most common causes of bridge failures. Scour occurs due to the erosion of soil and sediment within a channel with flowing water. During a flood event, the extent of scour can be so great that it can destabilize an existing bridge structure. In order to evaluate the scour potential of a bridge, it is necessary to have information regarding the substructure, particularly the bridge foundations. However, as of 2011 there are more than 40,000 bridges across United States with unknown foundations. Generally for these bridges there are no design or as-built plans available to show the type, depth, geometry, or materials incorporated into the foundations. Several non-destructive testing (NDT) methods have been developed to evaluate these unknown foundations. The primary objective of this research is to identify the most current and widely used NDT methods for determining the embedment depth of unknown bridge foundations and to compare these methods to an ultrasonic P-wave reflection imaging system. The ultrasonic P-wave reflection system has tremendous potential to provide more information and address several short-comings of other NDT methods. A laboratory study was initiated to explore various aspects related to the P-wave system performance, in order to characterize the limitations of the system in evaluation of unknown foundations prior to deployment in field studies. Moreover, field testing was performed using the P-wave system and a number of the current NDT methods at two selected bridge foundations to allow comparison between the results.
19. P-wave morphology during right atrial pacing before and after atrial flutter ablation--a new marker for success.
PubMed
Hamdan, M H; Kalman, J M; Barron, H V; Lesh, M D
1997-05-15
Fourteen patients with typical atrial flutter underwent pacing from the low lateral right atrium and the proximal coronary sinus in normal sinus rhythm before and after catheter ablation. During low lateral right atrial pacing, a positive change in P-wave morphology in the inferior leads was noted in every patient (n = 12) in whom bidirectional block was achieved; no recurrence was noted in any of these patients. PMID:9165174
20. Analysis of near-source contributions to early P-wave coda for underground explosions. 1. Wave form complexity
L. Thorne; J. L. Welc
1987-01-01
A data set of more than 1600 teleseismic short-period P waves from 46 nuclear explosions is analyzed to establish near-source contributions to the first 15 sec of the P signals. The near-source components are isolated by event-to-event comparisons of first-cycle magnitudes, RMS amplitudes in the first 5 and next 10 sec of the wave forms, and energy temporal centroid measurements.
1. [P-wave ekg averaging technique--a new method of selecting patients with paroxysmal atrial fibrillation].
PubMed
Opolski, G; Kraska, T; Piatkowska-Janko, E; S?omka, K; Górecki, A; Stanis?awska, J; Scis?o, P; Piatkowski, A; Cieciura, M
1995-10-01
The aim of study was to assess the value of signal averaged ecg for detection of patients (pts) at risk for paroxysmal atrial fibrillation (paf). We examined three groups of pts: group I-41 pts with nonvalvular paf, group II-20 pts with hypertension and/or ischemic heart disease without paf and group 3-26 health persons, without organic heart disease. In all pts the signal-averaged electrocardiogram triggered by P waves was recorded. Seven parameters of the spatial magnitude of filtered P wave were measured. Significant difference between group I and group II or III was found in most parameters. Using the method of multidimensional variance analysis we constructed "the diagnostic vector" in multidimensional parameters space, which was used to determine patients belonging to group. Total percent of right decision was 85%. These findings suggest that pts at risk for paf could be detected while in sinus rhythm by using the P wave-triggered signal-averaged ecg. PMID:8650057
2. Comparison of P-wave dispersion in healthy dogs, dogs with chronic valvular disease and dogs with disturbances of supraventricular conduction
PubMed Central
2011-01-01
Background P-wave dispersion (Pd) is a new ECG index used in human cardiology and veterinary medicine. It is defined as the difference between the maximum and the minimum P-wave duration recorded from multiple different ECG leads. So far no studies were performed assessing the importance of P-wave dispersion in dogs. Methods The current study was aimed at determining proper value of Pd in healthy dogs (group I), dogs with chronic valvular disease (group II) and dogs with disturbances of supraventricular conduction (group III). The tests were carried out in 53 healthy dogs, 23 dogs with chronic valvular disease and 12 dogs with disturbances of supraventricular conduction of various breeds, sexes and body weight from 1,5 to 80 kg, aged between 0,5 and 17 years, submitted to the ECG examination. ECG was acquired in dogs in a standing position with BTL SD-8 electrocardiographic device and analyzed once the recording was enlarged. P-wave duration was calculated in 9 ECG leads (I, II, III, aVR, aVL, aVF, V1, V2, V4) from 5 cardiac cycles. Results The proper P-wave dispersion in healthy dogs was determined at up to 24 ms. P-wave dispersion was statistically significant increased (p < 0.01) in dogs with chronic valvular disease and dogs with disturbances of supraventricular conduction. In dogs with the atrial enlargement the P-wave dispersion is also higher than in healthy dogs, although no significant correlation between the size of left atria and Pd was noticed (p = 0.1, r = 0,17). Conclusions The P-wave dispersion is a constant index in healthy dogs, that is why it can be used for evaluating P wave change in dogs with chronic valvular disease and in dogs with disturbances of supraventricular conduction. PMID:21396110
3. Determining Mars parking orbits which ensure in-plane arrival and departure burns
NASA Technical Reports Server (NTRS)
Desai, Prasun N.; Buglia, James J.
1992-01-01
A numerical method to find suitable Mars parking orbits is developed which takes into account geometries associated with the asymptotes, along with the nodal precession caused by the oblateness of Mars. A selected orbital plane which contains the arrival asymptote precesses through the stay time to the plane also containing the departure asymptote. The parking orbit is co-planar with both the arrival and departure asymptotes and only in-plane burns are required at both Mars arrival and departure. The need for a plane change at Mars departure to achieve the proper velocity vector for earth return is eliminated. The method requires very little computation time to determine a set of all possible inclinations and right ascensions of the ascending nodes.
4. P-1 truss arrival at KSC
NASA Technical Reports Server (NTRS)
2000-01-01
On July 26, 2000 the P-1 truss arrived at Kennedy Space Center's Shuttle Landing Facility aboard its 'Super Guppy' transport. The truss was loaded onto a flatbed truck in preparation for movement to the Operations and Checkout Building for processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, SO, during the spring assembly flight. The 33,000- pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the International Space Station's radiators away from the sun to increase their maximum cooling efficiency.
5. P-1 truss arrival at KSC
NASA Technical Reports Server (NTRS)
2000-01-01
On July 26, 2000 the P-1 truss arrived at Kennedy Space Center's Shuttle Landing Facility aboard its 'Super Guppy' transport. The transport's cargo bay was opened showing the American flag and NASA logo as the P-1 truss was off loaded in preparation for movement to the Operations and Checkout Building for processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, SO, during the spring assembly flight. The 33,000- pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the International Space Station's radiators away from the sun to increase their maximum cooling efficiency.
6. P-1 truss arrival at KSC
NASA Technical Reports Server (NTRS)
2000-01-01
On July 26, 2000 the P-1 truss arrived at Kennedy Space Center's Shuttle Landing Facility aboard its 'Super Guppy' transport. The transport's cargo bay was opened showing the American flag and NASA logo as the P-1 truss was off loaded in preparation for movement to the Operations and Checkout Building for processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, SO, during the spring assembly flight. The 33,000- pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the International Space Station's radiators away form the sun to increase their maximum cooling efficiency.
7. P-1 truss arrival at KSC
NASA Technical Reports Server (NTRS)
2000-01-01
On July 26, 2000 the P-1 truss arrived at Kennedy Space Center's Shuttle Landing Facility aboard its 'Super Guppy' transport. A flatbed truck was backed up to begin the off loading of the P-1 truss in preparation for movement to the Operations and Checkout Building for processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, SO, during the spring assembly flight. The 33,000-pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the International Space Station's radiators away from the sun to increase their maximum cooling efficiency.
8. P-1 truss arrival at KSC
NASA Technical Reports Server (NTRS)
2000-01-01
On July 26, 2000 the P-1 truss arrived at Kennedy Space Center's Shuttle Landing Facility aboard its 'Super Guppy' transport. The truss was loaded by crane onto a flatbed truck in preparation for movement to the Operations and Checkout Building for processing. The P-1 truss, scheduled to fly in spring of 2002, is part of a total 10-truss, girder-like structure that will ultimately extend the length of a football field. Astronauts will attach the 14-by-15 foot structure to the port side of the center truss, SO, during the spring assembly flight. The 33,000- pound P-1 will house the thermal radiator rotating joint (TRRJ) that will rotate the International Space Station's radiators away from the sun to increase their maximum cooling efficiency.
9. STS-83 Crew Arrival for TCDT
NASA Technical Reports Server (NTRS)
1997-01-01
Members of the STS-83 flight crew pose alongside a T-33 jet trainer aircraft after arriving at the KSC Shuttle Landing Facility for Terminal Countdown Demonstration (TCDT) exercises for that space flight. They are (left to right) Payload Specialist Roger K. Crouch; Pilot Susan L. Still; Mission Commander James D. Halsell, Jr.; Mission Specialist Michael L. Gernhardt; Payload Specialist She is the second woman to fly in this capacity on the Space Shuttle. The Microgravity Science Laboratory-1 (MSL-1) Spacelab module is the primary payload on this 16-day mission. The MSL-1 will used to test some of the hardware, facilities and procedures that are planned for use on the International Space Station, while the seven-member crew conducts combustion, protein crystal growth and materials processing experiments.
10. Distribution of Arrival Times of Air Shower Particles
P. Bassi; G. Clark; B. Rossi
1953-01-01
We have studied the instantaneous distribution of particles in extensive air showers at sea level by measuring the relative delays between particles with three liquid scintillation counters. The delays measured were in the range from 5 to 300 mmusec. The sizes of the showers were in the range from 105 to 106 particles. Using statistical methods of analysis we have
11. Morning, Midday Most Common Time for Babies' Arrival, Study Finds
MedlinePLUS
... typically occurred in the early morning -- after 1 a.m. "In general, these births have fewer interventions, and ... hospital births in 2013 occurred in the 8 a.m. hour, and another 6 percent at the noon ...
12. STRONG FIELD EFFECTS ON PULSAR ARRIVAL TIMES: GENERAL ORIENTATIONS
SciTech Connect
Wang Yan [Department of Astronomy, Nanjing University, Nanjing 210093 (China); Creighton, Teviet; Price, Richard H.; Jenet, Frederick A. [Center for Gravitational Wave Astronomy and Department of Physics and Astronomy, University of Texas at Brownsville, Brownsville, Texas 78520 (United States)
2009-11-10
A pulsar beam passing close to a black hole can provide a probe of very strong gravitational fields even if the pulsar itself is not in a strong field region. In the case that the spin of the hole can be ignored, we have previously shown that all strong field effects on the beam can be understood in terms of two 'universal' functions: F(phi{sub in}) and T(phi{sub in}) of the angle of beam emission phi{sub in}; these functions are universal in that they depend only on a single parameter, the pulsar/black hole distance from which the beam is emitted. Here we apply this formalism to general pulsar-hole-observer geometries, with arbitrary alignment of the pulsar spin axis and arbitrary pulsar beam direction and angular width. We show that the analysis of the observational problem has two distinct elements: (1) the computation of the location and trajectory of an observer-dependent 'keyhole' direction of emission in which a signal can be received by the observer; and (2) the determination of an annulus that represents the set of directions containing beam energy. Examples of each are given along with an example of a specific observational scenario.
13. Airborne Precision Spacing (APS) Dependent Parallel Arrivals (DPA)
NASA Technical Reports Server (NTRS)
Smith, Colin L.
2012-01-01
The Airborne Precision Spacing (APS) team at the NASA Langley Research Center (LaRC) has been developing a concept of operations to extend the current APS concept to support dependent approaches to parallel or converging runways along with the required pilot and controller procedures and pilot interfaces. A staggered operations capability for the Airborne Spacing for Terminal Arrival Routes (ASTAR) tool was developed and designated as ASTAR10. ASTAR10 has reached a sufficient level of maturity to be validated and tested through a fast-time simulation. The purpose of the experiment was to identify and resolve any remaining issues in the ASTAR10 algorithm, as well as put the concept of operations through a practical test.
14. STS-93 crew leaves SLF after arrival for launch
NASA Technical Reports Server (NTRS)
1999-01-01
The STS-93 crew leave the Shuttle Landing Facility after answering questions for the media and posing for photographers, whose shadows stretch across the SLF. From left are Mission Specialists Michel Tognini of France, who is with the Centre National d'Etudes Spatiales (CNES) and Steven A. Hawley (Ph.D.), Commander Eileen M. Collins (waving), Mission Specialist Catherine G. 'Cady' Coleman (Ph.D.), and Pilot Jeffrey S. Ashby. The crew arrived at KSC for pre-launch activities. Collins is the first woman to serve as mission commander. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes.
15. Optimal Integration of Departures and Arrivals in Terminal Airspace
NASA Technical Reports Server (NTRS)
Xue, Min; Zelinski, Shannon Jean
2013-01-01
Coordination of operations with spatially and temporally shared resources, such as route segments, fixes, and runways, improves the efficiency of terminal airspace management. Problems in this category are, in general, computationally difficult compared to conventional scheduling problems. This paper presents a fast time algorithm formulation using a non-dominated sorting genetic algorithm (NSGA). It was first applied to a test problem introduced in existing literature. An experiment with a test problem showed that new methods can solve the 20 aircraft problem in fast time with a 65% or 440 second delay reduction using shared departure fixes. In order to test its application in a more realistic and complicated problem, the NSGA algorithm was applied to a problem in LAX terminal airspace, where interactions between 28% of LAX arrivals and 10% of LAX departures are resolved by spatial separation in current operations, which may introduce unnecessary delays. In this work, three types of separations - spatial, temporal, and hybrid separations - were formulated using the new algorithm. The hybrid separation combines both temporal and spatial separations. Results showed that although temporal separation achieved less delay than spatial separation with a small uncertainty buffer, spatial separation outperformed temporal separation when the uncertainty buffer was increased. Hybrid separation introduced much less delay than both spatial and temporal approaches. For a total of 15 interacting departures and arrivals, when compared to spatial separation, the delay reduction of hybrid separation varied between 11% or 3.1 minutes and 64% or 10.7 minutes corresponding to an uncertainty buffer from 0 to 60 seconds. Furthermore, as a comparison with the NSGA algorithm, a First-Come-First-Serve based heuristic method was implemented for the hybrid separation. Experiments showed that the results from the NSGA algorithm have 9% to 42% less delay than the heuristic method with varied uncertainty buffer sizes.
16. Survival probability of an edge Majorana in a one-dimensional p-wave superconducting chain under sudden quenching of parameters
Rajak, Atanu; Dutta, Amit
2014-04-01
We consider the temporal evolution of a zero-energy edge Majorana of a spinless p-wave superconducting chain following a sudden change of a parameter of the Hamiltonian. Starting from one of the topological phases that has an edge Majorana, the system is suddenly driven to the other topological phase or to the (topologically) trivial phases and to the quantum critical points (QCPs) separating these phases. The survival probability of the initial edge Majorana as a function of time is studied following the quench. Interestingly when the chain is quenched to the QCP, we find a nearly perfect oscillation of the survival probability, indicating that the Majorana travels back and forth between two ends, with a time period that scales with the system size. We also generalize to the situation when there is a next-nearest-neighbor hopping in a superconducting chain and there results in a pair of edge Majorana at each end of the chain in the topological phase. We show that the frequency of oscillation of the survival probability gets doubled in this case. We also perform an instantaneous quenching of the Hamiltonian (with two Majorana modes at each end of the chain) to an another Hamiltonian which has only one Majorana mode in equilibrium; the MSP shows oscillations as a function of time with a noticeable decay in the amplitude. On the other hand for a quenching which is reverse to the previous one, the MSP decays rapidly and stays close to zero with fluctuations in amplitude.
17. Body surface mapping during pacing at multiple sites in the human atrium: P-wave morphology of ectopic right artrial activation
Arne SippensGroenewegen; Heidi A. P. Peeters; Emile R. Jessurun; Andre C. Linnenbank; Etienne O. Robles de Medina; Michael D. Lesh; Hemel van N. M
1998-01-01
Background—The morphology and polarity of the P wave on 12-lead ECG are of limited clinical value in localizing ectopic atrial rhythms. It was the aim of this study to assess the spatial resolution of body surface P-wave integral mapping in identifying the site of origin of ectopic right atrial (RA) impulse formation in patients without structural atrial disease. Methods and
18. A simple and efficient class of functions to model arrival curve of packetised flows
E-print Network
Paris-Sud XI, Université de
traffic constraints and service contracts with arrival curves and service curves. As usual in modelling-BASED SYSTEMS]: Real-time and embedded systems 1. INTRODUCTION Context of the problem. Aircrafts today embed hun or affiliate of the na- tional government of France. As such, the government of France retains a nonexclusive
19. Analysis of delay reducing and fuel saving sequencing and spacing algorithms for arrival traffic
NASA Technical Reports Server (NTRS)
Neuman, Frank; Erzberger, Heinz
1991-01-01
The air traffic control subsystem that performs sequencing and spacing is discussed. The function of the sequencing and spacing algorithms is to automatically plan the most efficient landing order and to assign optimally spaced landing times to all arrivals. Several algorithms are described and their statistical performance is examined. Sequencing brings order to an arrival sequence for aircraft. First-come-first-served sequencing (FCFS) establishes a fair order, based on estimated times of arrival, and determines proper separations. Because of the randomness of the arriving traffic, gaps will remain in the sequence of aircraft. Delays are reduced by time-advancing the leading aircraft of each group while still preserving the FCFS order. Tightly spaced groups of aircraft remain with a mix of heavy and large aircraft. Spacing requirements differ for different types of aircraft trailing each other. Traffic is reordered slightly to take advantage of this spacing criterion, thus shortening the groups and reducing average delays. For heavy traffic, delays for different traffic samples vary widely, even when the same set of statistical parameters is used to produce each sample. This report supersedes NASA TM-102795 on the same subject. It includes a new method of time-advance as well as an efficient method of sequencing and spacing for two dependent runways.
20. Broadband Direction-Of-Arrival Estimation Based on Second Order Statistics
Justinian P. Rosca; Joseph Ó Ruanaidh; Alexander Jourjine; Scott Rickard
1999-01-01
wideband sources recorded using closely spaced receivers can feasibly be separated based only on second order statistics when using a physical model of the mixing process. In this case we show that the parameter estimation problem can be essentially reduced to considering directions of arrival and attenuations of each signal. The paper presents two demixing methods operating in the time
1. Student will be arriving ________ minutes late Student will be leaving ________ minutes early
E-print Network
Calgary, University of
: Date: Faculty/Instructor agrees to support the student by allowing student to defer any final examinations related to the above Time Conflict in the event that the student requests it. FacultyStudent will be arriving ________ minutes late Student will be leaving ________ minutes early
2. ECOLOGY AND POPULATION BIOLOGY Species Assemblage Arriving at and Emerging from Trees Colonized
E-print Network
Aukema, Brian
by Ips pini in the Great Lakes Region: Partitioning by Time Since Colonization, Season, and Host Species, resource partitioning, tritrophic interactions, kairo- mones THE PINE ENGRAVER, Ips pini (Say) (Coleoptera of insects that arrive at and reproduce in trees colonized byI. pini, and how this assemblage is partitioned
3. Electronic structure and spontaneous internal field around nonmagnetic impurities in spin-triplet chiral p -wave superconductors
Takigawa, Mitsuaki; Ichioka, Masanori; Kuroki, Kazuhiko; Tanaka, Yukio
2005-12-01
The electronic structure around an impurity in spin-triplet p -wave superconductors is studied by the Bogoliubov-de Gennes theory on a tight-binding model, where we have chosen sinpx+isinpy -wave or sin(px+py)+isin(-px+py) -wave states, which are considered to be candidates for the pairing state in Sr2RuO4 . We calculate the spontaneous current and the local density of states around the impurity and discuss the difference between the two types of pairing. We propose that it is possible to discriminate the two pairing states by studying the spatial dependence of the magnetic field around a pair of impurities.
4. Influence of spin-orbit coupling on differential conductance of normal metal/ferromagnetic p wave superconductor junctions
Li, Xiaowei; Liu, Shujing; Chen, Huabao
2013-10-01
The extended Blonder-Tinkham-Klapwijk model is applied to studying tunneling conductance in normal metal/ferromagnetic p wave superconductor junctions. It is found that the spin-orbit scattering at the interfaces significantly affects the tunneling conductance. The interface spin-orbit coupling (SOC) suppresses the split conductance peaks in the N/ferromagnetic px wave superconductor junction and enhances the zero-bias conductance dip (ZBCD) of py wave superconductor junction. The SOC gives rise to the asymmetry of the conductance spectrum in the ferromagnetic px + py wave superconductor junctions.
5. Role of P-wave inelasticity in J/{psi}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup 0}
SciTech Connect
Guo Peng; Mitchell, Ryan [Physics Department, Indiana University, Bloomington, Indiana 47405 (United States); Szczepaniak, Adam P. [Physics Department, Indiana University, Bloomington, Indiana 47405 (United States); Center for the Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States)
2010-11-01
We discuss the importance of inelasticity in the P-wave {pi}{pi} amplitude on the Dalitz distribution of 3{pi} events in J/{psi} decay. The inelasticity, which becomes sizable for {pi}{pi} masses above 1.4 GeV, is attributed to KK{yields}{pi}{pi} rescattering. We construct an analytical model for the two-channel scattering amplitude and use it to solve the dispersion relation for the isobar amplitudes that parametrize the J/{psi} decay. We present comparisons between theoretical predictions for the Dalitz distribution of 3{pi} events with available experimental data.
6. Ferromagnetism stabilized by lattice distortion at the surface of the p-wave superconductor Sr(2)RuO(4)
PubMed
Matzdorf; Fang; Ismail; Zhang; Kimura; Tokura; Terakura; Plummer
2000-08-01
Ferromagnetic (FM) spin fluctuations are believed to mediate the spin-triplet pairing for the p-wave superconductivity in Sr(2)RuO(4). Our experiments show that, at the surface, a bulk soft-phonon mode freezes into a static lattice distortion associated with an in-plane rotation of the RuO(6) octahedron. First-principle calculations confirm this structure and predict a FM ground state at the surface. This coupling between structure and magnetism in the environment of broken symmetry at the surface allows a reconsideration of the coupling mechanism in the bulk. PMID:10926529
7. A deeper statistical examination of arrival dates of migratory breeding birds in relation to global climate change.
PubMed
Wilson, W Herbert
2013-01-01
Using an 18-year dataset of arrival dates of 65 species of Maine migratory breeding birds, I take a deeper view of the data to ask questions about the shapes of the distribution. For each year, most species show a consistent right-skewed pattern of distribution, suggesting that selection is stronger against individuals that arrive too early compared to those that arrive later. Distributions are consistently leptokurtic, indicating a narrow window of optimal arrival dates. Species that arrive earlier in the spring show higher skewness and kurtosis values. Nectarivorous species showed more pronounced skewness. Wintering area did not explain patterns of skewness or kurtosis. Deviations from average temperatures and the North Atlantic Oscillation index explained little variation in skewness and kurtosis. When arrival date distributions are broken down into different medians (e.g., 5% median and 75% median), stronger correlations emerge for portions of the distribution that are adjacent, suggesting species fine-tune the progress of their migration. Interspecific correlations for birds arriving around the same time are stronger for earliest migrants (the 25% median) compared to the true median and the 75% median. PMID:24832806
8. 27 CFR 26.128 - Taxpayment at port of arrival.
Code of Federal Regulations, 2012 CFR
2012-04-01
...AND THE VIRGIN ISLANDS Liquors and Articles Purchased by Tourists in Puerto Rico § 26.128 Taxpayment at port of arrival...articles is not paid in Puerto Rico, it shall be paid by the tourist at the port of arrival prior to release of the liquors...
9. 27 CFR 26.128 - Taxpayment at port of arrival.
Code of Federal Regulations, 2013 CFR
2013-04-01
...AND THE VIRGIN ISLANDS Liquors and Articles Purchased by Tourists in Puerto Rico § 26.128 Taxpayment at port of arrival...articles is not paid in Puerto Rico, it shall be paid by the tourist at the port of arrival prior to release of the liquors...
10. 27 CFR 26.128 - Taxpayment at port of arrival.
Code of Federal Regulations, 2014 CFR
2014-04-01
...AND THE VIRGIN ISLANDS Liquors and Articles Purchased by Tourists in Puerto Rico § 26.128 Taxpayment at port of arrival...articles is not paid in Puerto Rico, it shall be paid by the tourist at the port of arrival prior to release of the liquors...
11. 27 CFR 26.128 - Taxpayment at port of arrival.
Code of Federal Regulations, 2010 CFR
2010-04-01
...AND THE VIRGIN ISLANDS Liquors and Articles Purchased by Tourists in Puerto Rico § 26.128 Taxpayment at port of arrival...articles is not paid in Puerto Rico, it shall be paid by the tourist at the port of arrival prior to release of the liquors...
12. 27 CFR 26.128 - Taxpayment at port of arrival.
Code of Federal Regulations, 2011 CFR
2011-04-01
...AND THE VIRGIN ISLANDS Liquors and Articles Purchased by Tourists in Puerto Rico § 26.128 Taxpayment at port of arrival...articles is not paid in Puerto Rico, it shall be paid by the tourist at the port of arrival prior to release of the liquors...
13. Doctoral Symposium ICRAT 2014 Optimization of Arrival and Departure
E-print Network
is proposed for aircraft routings that minimizes the noise impact in the residential communities surrounding of the flights. Optimizing departure and arrival procedures is therefore crucial to regulate air traffic flow and arrival routes at a strategic level in 3D is interesting as it may help to regulate air traffic flow
14. Nearest Neighbour Algorithms for Forecasting Call Arrivals in Call Centers
Sandjai Bhulai; Wing Hong Kan; Elena Marchiori
In this paper we study a nearest neighbour algorithm for forecasting call arrivals to call centers. The algorithm does not require an underlying model for the arrival rates and it can be applied to historical data without pre-processing it. We show that this class of algorithms provides a more accurate forecast when compared to the conven- tional method that simply
15. Does Pet Arrival Trigger Prosocial Behaviors in Individuals with Autism?
E-print Network
Paris-Sud XI, Université de
Does Pet Arrival Trigger Prosocial Behaviors in Individuals with Autism? Marine Grandgeorge1 Brest, Ho^pital de Bohars, Centre de Ressources Autisme, Bohars, France, 2 UMR-CNRS 6552, Laboratoire between the presence or the arrival of pets in families with an individual with autism and the changes
16. Arrival direction of late sound and listener envelopment
Hiroshi Furuya; Kazutoshi Fujimoto; Choi Young Ji; Noriaki Higa
2001-01-01
The purpose of this study is to investigate the relation between the arrival direction of late sound and perceived listener envelopment (LEV). In this paper, two kinds of psychological experiments are conducted with three-dimensional simulated sound fields in an anechoic room. Firstly, the effect of late energy arriving from four fundamental directions on perceived LEV is individually investigated. The results
17. Theoretical and numerical comparison of 3D numerical schemes for their accuracy with respect to P-wave to S-wave speed ratio
Moczo, P.; Kristek, J.; Galis, M.; Chaljub, E.; Chen, X.; Zhang, Z.
2012-04-01
Numerical modeling of earthquake ground motion in sedimentary basins and valleys often has to account for the P-wave to S-wave speed ratios (VP/VS) as large as five and even larger, mainly in sediments below groundwater level. The ratio can attain values larger than 10 - the unconsolidated lake sediments in Ciudad de México are a good example. At the same time, accuracy of the numerical schemes with respect to VP/VS has not been sufficiently analyzed. The numerical schemes are often applied without adequate check of the accuracy. We present theoretical analysis and numerical comparison of 18 3D numerical time-domain explicit schemes for modeling seismic motion for their accuracy with the varying VP/VS. The schemes are based on the finite-difference, spectral-element, finite-element and discontinuous-Galerkin methods. All schemes are presented in a unified form. Theoretical analysis compares accuracy of the schemes in terms of local errors in amplitude and vector difference. In addition to the analysis we compare numerically simulated seismograms with exact solutions for canonical configurations. We compare accuracy of the schemes in terms of the local errors, grid dispersion and full wavefield simulations with respect to the structure of the numerical schemes.
18. Analysis and interpretation of compressional (P-wave) and shear (SH-wave) reflection seismic and geologic data over the Bane Dome, Giles County, Virginia
Gresko, M. J.
Approximately 37 km of predominantly 24-fold p-wave Vibroseis data and 16 km of 24-fold SH-wave Vibroseis data were acquired the southern portion of the folded Appalachians near the Bane Dome in Giles County, Virginia. Data processing techniques included the application of newly developed methods for crossdip removal as well as the determination of static solutions in the case of time variant shifts within the data traces. Minimum-phase filter deconvolution was also applied for the removal of reverberating energy and multiples recorded on the SH-wave lines. V sub p/ V sub s ratios were used to aid in the determination of lithologies in the absence of bore-hole data. Interpreted thicknening of the Lower Cambriano to Upper Precambrian sequence beneath the Bane Dome appears to represent Eocambrian rifting. Faults generated at that time may now be reactivated by the present stress regime, causing earthquake activity in this area. Interpretation of the seismic data supports a duplex structure proposed for the Paleozoic rocks of the Bane Dome Complex within the Narrows thrust sheet of southwestern Virginia.
19. GHz ultrasonic interferometry in a diamond anvil cell: P-wave velocities in periclase to 4.4 GPa and 207°C
Shen, A. H.; Reichmann, H.-J.; Chen, G.; Angel, R. J.; Bassett, W. A.; Spetzler, H.
P-wave velocities in periclase were determined up to 4.4 GPa and 207°C using a GHz ultrasonic interferometer and a resistance-heated diamond anvil cell. The samples were disks of synthetic periclase single crystal cut parallel to the (100) plane with dimensions of 300 ?m in diameter and 46 ?m in thickness. A 250-?m-thick tungsten-tantalum alloy as well as rhenium foils were used as gaskets. The signal was introduced through a buffer rod which was directly coupled to one of the diamond anvils by means of force applied to the buffer rod. The sample was coupled to one of the diamond anvils by means of normal force applied from the pressure medium, which was a fine-grain potassium bromide powder. The pressures in room temperature runs were determined by ruby fluorescence. Least squares fitting to the elastic constants derived from our experimental data yield c11 (GPa) = 296.8(±0.7) + 10.9(±0.9) × P (GPa). The results are in good agreement with previous determinations using ultrasonic interferometry on larger samples at lower frequencies and at lower pressures. The ultrasonic signals obtained in the high-temperature runs showed no deterioration in quality, and we were able to obtain travel-time data. By extrapolating the results from earlier work, we were able to estimate the pressure in the sample chamber while at high temperatures using the travel-time data.
20. Illuminating the near-sonic rupture velocities of the intracontinental Kokoxili Mw 7.8 and Denali fault Mw 7.9 strike-slip earthquakes with global P wave back projection imaging
Walker, Kristoffer T.; Shearer, Peter M.
2009-02-01
The Denali and Kokoxili strike-slip earthquakes are two of the longest recent intracontinental ruptures. Previous studies report a range of rupture velocities. Here we image these earthquakes by reverse time migration of the intermediate-frequency P wave train recorded by global broadband seismometers. This technique permits a relatively direct measure of rupture velocity (speed and direction) as constrained by the radiated seismic energy, free from restrictive assumptions or rupture speed bounds placed on the solution. We compare our results with published seismic, GPS displacement, and surface slip inversion results. Both ruptures were initially subshear and transitioned over a distance no longer than 40 km to supershear speeds close to the P wave speed of ˜5.6 km/s. We investigate the accuracy of our results with synthetic data and experiment with using different imaging parameters and seismic subnetworks. These tests allow us to rule out the possibility of subshear speeds along the supershear segments. Although we cannot exclude supershear speeds of 4.5-6.5 km/s, our most reliable rupture velocities of ˜5.6 km/s are close to the local P wave speeds. We hypothesize that these intracontinental faults have weak shear strengths or high breakdown slips or crustal rigidities and experience at least moderate slip or slip rate weakening. Our observations and previous published results lead us to speculate that very long, surface-extending faults with general homogeneity in prestress and fault strength, together with smaller adjacent fault segments to provide triggering, may be necessary ingredients for the sub-Rayleigh to supershear rupture speed transition in strike-slip earthquakes.
1. A model for P-wave attenuation and dispersion in a porous medium permeated by aligned fractures
Brajanovski, Miroslav; Gurevich, Boris; Schoenberg, Michael
2005-10-01
Fractures in a porous rock can be modelled as very thin and highly porous layers in a porous background. First, a dispersion equation for a P wave propagating in periodically layered poroelastic medium is obtained using propagator matrix approach applied to Biot equations of poroelasticity with periodic coefficients. Then in the limit of low stiffness and thickness this dispersion equation yields an expression for the effective P-wave modulus of the fractured porous material. When both pores and fractures are dry, this material is equivalent to a transversely isotropic elastic porous material with linear-slip interfaces. When saturated with a liquid this material exhibits significant attenuation and velocity dispersion due to wave-induced fluid flow between pores and fractures. In the low-frequency limit the material properties are equal to those obtained by anisotropic Gassmann (or Brown-Korringa) theory applied to a porous material with linear-slip interfaces. At low frequencies inverse quality factor scales with the first power of frequency ?. At high frequencies the effective elastic properties are equal to those for isolated fluid-filled fractures in a solid (non-porous) background, and inverse quality factor scales with ?-1/2. The magnitude of both attenuation and dispersion strongly depends on both the degree of fracturing and background porosity of the medium. The characteristic frequency of the attenuation and dispersion depends on the background permeability, fluid viscosity, as well as fracture density and spacing.
2. Analysis of near-source contributions to early P-wave coda for underground explosions. 1. Wave form complexity
SciTech Connect
Thorne, L.; Welc, J.L.
1987-06-01
A data set of more than 1600 teleseismic short-period P waves from 46 nuclear explosions is analyzed to establish near-source contributions to the first 15 sec of the P signals. The near-source components are isolated by event-to-event comparisons of first-cycle magnitudes, RMS amplitudes in the first 5 and next 10 sec of the wave forms, and energy temporal centroid measurements. Events from the Nevada, Amchitka, and Novaya Zemlya test sites are analyzed separately to characterize overall source-region variations. Event-averaged waveform complexity variations between explosions within a given site are tested for dependence on source strength, burial depth, location within the site, and tectonic release. Azimuthal patterns of the individual event complexity anomalies are used to discriminate between possible near-source influences. For events at Pahute Mesa, a strong azimuthal amplitude pattern in both the direct P waves and the P coda for all of the events is produced principally by deep mantle variations. Defocusing by a high-velocity anomaly in the crust and uppermost mantle beneath the site has a stronger effect on the direct P signals than on the early P coda, resulting in a systematic, spatially varying relative pattern.
3. How Green Will Electricity beHow Green Will Electricity be When Electric Vehicles Arrive?When Electric Vehicles Arrive?
E-print Network
How Green Will Electricity beHow Green Will Electricity be When Electric Vehicles Arrive?When Electric Vehicles Arrive? Edward S. Rubin Department of Engineering and Public Policy Department-carbon electricity and plug-in hybrid electric vehicles (PHEVs) ? · In light of the above, would adoption of PHEVs
4. A practical database method for predicting arrivals of “average” interplanetary shocks at Earth
X. S. Feng; Y. Zhang; W. Sun; M. Dryer; C. D. Fry; C. S. Deehr
2009-01-01
A practical database method for predicting the interplanetary shock arrival time at L1 point is presented here. First, a shock transit time database (hereinafter called Database-I) based on HAFv.1 (version 1 of the Hakamada-Akasofu-Fry model) is preliminarily established with hypothetical solar events. Then, on the basis of the prediction test results of 130 observed solar events during the period from
5. the P-wave upper mantle structure beneath an active spreading center: The Gulf of California
NASA Technical Reports Server (NTRS)
Walck, M. C.
1983-01-01
Detailed analysis of short period travel time, and waveform data reveals the upper mantle structure beneath an oceanic ridge to depths of 900 km. More than 1400 digital seismograms from earthquakes in Mexico and central America recorded at SCARLET yield 1753 travel times and 58 direct measurements of short period travel time as well as high quality, stable waveforms. The 29 events combine to form a continuous record section from 9 deg to 40 deg with an average station spacing of less than 5 km. First the travel times are inverted. Further constraints arise from the observed relative amplitudes of mantle phases, which are modeled by trial and error.
6. What prevents phenological adjustment to climate change in migrant bird species? Evidence against the `arrival constraint'' hypothesis
Goodenough, Anne E.; Hart, Adam G.; Elliot, Simon L.
2011-01-01
Phenological studies have demonstrated changes in the timing of seasonal events across multiple taxonomic groups as the climate warms. Some northern European migrant bird populations, however, show little or no significant change in breeding phenology, resulting in synchrony with key food sources becoming mismatched. This phenological inertia has often been ascribed to migration constraints (i.e. arrival date at breeding grounds preventing earlier laying). This has been based primarily on research in The Netherlands and Germany where time between arrival and breeding is short (often as few as 9 days). Here, we test the arrival constraint hypothesis over a 15-year period for a U.K. pied flycatcher ( Ficedula hypoleuca) population where laying date is not constrained by arrival as the period between arrival and breeding is substantial and consistent (average 27 ± 4.57 days SD). Despite increasing spring temperatures and quantifiably stronger selection for early laying on the basis of number of offspring to fledge, we found no significant change in breeding phenology, in contrast with co-occurring resident blue tits ( Cyanistes caeruleus). We discuss possible non-migratory constraints on phenological adjustment, including limitations on plasticity, genetic constraints and competition, as well as the possibility of counter-selection pressures relating to adult survival, longevity or future reproductive success. We propose that such factors need to be considered in conjunction with the arrival constraint hypothesis.
7. Knowledge-Based Scheduling of Arrival Aircraft in the Terminal Area
NASA Technical Reports Server (NTRS)
Krzeczowski, K. J.; Davis, T.; Erzberger, H.; Lev-Ram, Israel; Bergh, Christopher P.
1995-01-01
A knowledge based method for scheduling arrival aircraft in the terminal area has been implemented and tested in real time simulation. The scheduling system automatically sequences, assigns landing times, and assign runways to arrival aircraft by utilizing continuous updates of aircraft radar data and controller inputs. The scheduling algorithm is driven by a knowledge base which was obtained in over two thousand hours of controller-in-the-loop real time simulation. The knowledge base contains a series of hierarchical 'rules' and decision logic that examines both performance criteria, such as delay reductions, as well as workload reduction criteria, such as conflict avoidance. The objective of the algorithm is to devise an efficient plan to land the aircraft in a manner acceptable to the air traffic controllers. This paper describes the scheduling algorithms, gives examples of their use, and presents data regarding their potential benefits to the air traffic system.
8. Stochastic Queueing Models for Air Transportation Systems with Scheduled Arrivals
E-print Network
Nikoleris, Anastasios Nikolaos
2011-01-01
or through simulation. For a surge of N aircraft arrivals,aircraft delays. The accuracy of the approximation method was assessed through simulationaircraft delays. The accuracy of the approximation method was demonstrated through simulation
9. 9 CFR 93.804 - Declaration upon arrival.
Code of Federal Regulations, 2014 CFR
2014-01-01
...CONTAINERS Elephants, Hippopotami, Rhinoceroses, and Tapirs § 93.804 Declaration...arrival of an elephant, hippopotamus, rhinoceros, or tapir at a port of entry...which the elephant, hippopotamus, rhinoceros, or tapir was shipped; (h)...
10. 9 CFR 93.804 - Declaration upon arrival.
Code of Federal Regulations, 2012 CFR
2012-01-01
...CONTAINERS Elephants, Hippopotami, Rhinoceroses, and Tapirs § 93.804 Declaration...arrival of an elephant, hippopotamus, rhinoceros, or tapir at a port of entry...which the elephant, hippopotamus, rhinoceros, or tapir was shipped; (h)...
11. 9 CFR 93.804 - Declaration upon arrival.
Code of Federal Regulations, 2011 CFR
2011-01-01
...CONTAINERS Elephants, Hippopotami, Rhinoceroses, and Tapirs § 93.804 Declaration...arrival of an elephant, hippopotamus, rhinoceros, or tapir at a port of entry...which the elephant, hippopotamus, rhinoceros, or tapir was shipped; (h)...
12. 9 CFR 93.804 - Declaration upon arrival.
Code of Federal Regulations, 2010 CFR
2010-01-01
...CONTAINERS Elephants, Hippopotami, Rhinoceroses, and Tapirs § 93.804 Declaration...arrival of an elephant, hippopotamus, rhinoceros, or tapir at a port of entry...which the elephant, hippopotamus, rhinoceros, or tapir was shipped; (h)...
13. 9 CFR 93.804 - Declaration upon arrival.
Code of Federal Regulations, 2013 CFR
2013-01-01
...CONTAINERS Elephants, Hippopotami, Rhinoceroses, and Tapirs § 93.804 Declaration...arrival of an elephant, hippopotamus, rhinoceros, or tapir at a port of entry...which the elephant, hippopotamus, rhinoceros, or tapir was shipped; (h)...
14. Director McNutt Arrives from Boat Tour in Tahoe
USGS Multimedia Gallery
Director Marcia McNutt from the USGS, Tim Rowe a hydrologist from the Nevada Water Center and Joanne Marchetta the Tahoe regional planning agency executive Director pose for the camera after arriving back from the boat tour in Tahoe....
15. Quantum phase transitions and phase diagram for a one-dimensional p-wave superconductor with an incommensurate potential.
PubMed
Cai, X
2014-04-16
The effect of the incommensurate potential is studied for the one-dimensional p-wave superconductor. It is determined by analyzing various properties, such as the superconducting gap, the long-range order of the correlation function, the inverse participation ratio and the Z2 topological invariant, etc. In particular, two important aspects of the effect are investigated: (1) as disorder, the incommensurate potential destroys the superconductivity and drives the system into the Anderson localized phase; (2) as a quasi-periodic potential, the incommensurate potential causes band splitting and turns the system with certain chemical potential into the band insulator phase. A full phase diagram is also presented in the chemical potential-incommensurate potential strength plane. PMID:24675766
16. Interplay of p-wave pairing potential and spin-orbit coupling in two-dimensional noncentrosymmetric superconductors
Sun, Ningning; Zhao, Jingxiang; Yan, Xu
2014-11-01
Both pairing potential and spin-orbit coupling (SOC) play important roles in two-dimensional noncentrosymmetric superconductivity. Supposing that p-wave pairing potential is present between quasiparticles, spin-singlet pairs arise and mix with spin-triplet pairs in the electron space. Our results show that the effect of SOC on the electron superconducting order parameters is different below and above a critical pairing potential VbarC. If the pairing potential VbarVbarC, increasing SOC leads to increment of the spin-singlet pairing, but reduction of the triplet one. Moreover, VbarC increases with SOC.
17. Estimated Moho Temperature from Observed Heat Flow and Comparison with P-Wave Velocity in the East Sea, Korea
Jung, W. Y.; Wood, W. T.
2014-12-01
We have estimated temperatures at the Moho surface by employing a published empirical relationship of Perry et al's work (JGR, doi:10.1029/2005JB003921) to the observed heat flow measurements in the East Sea (Sea of Japan), Korea. We assumed in our computation that the parameter values are all the same although the Perry et al's relationship between crustal thickness and heat flows to compute Moho temperature was derived for the Canadian Shield. For the heat flow data, we used the published global heat flow data (http://www.heatflow.und.edu) augmented with some recent heat flow measurements from Korea, and the LLN3_G3Dv3 for P-wave tomography model (JGR, doi:10.1029/2012JB009525). Preliminary results do not show a significant correlation between the computed Moho temperature and the P-wave velocity model perhaps due to uncertainty in the parameter values used in the computation as well as the empirical relation. An empirical relationship between the observed heat flow and the Moho temperature for the Canadian shield might be different for a backarec basin area like the East Sea, Korea. However, we noted that there exists a moderate negative correlation between the total crustal thickness and heat flow - less heat flows with increasing crustal thickness with a relation of Heat_Flow (mW/m2) = 205 - 18.3 * Crustal_Thickness (km). The modeled Moho temperature displays a trend of higher values (900o K -1400o K) from Japan toward the beneath of Yamato Basin and Rise in the NW direction, and beneath the Ulleung Basin area. Another higher Moho temperature (>1000o K) contour band is observed in the area north of Japan Basin, approximately centered along the 139.5o E.
18. Composite Anisotropies Revealed by P-Wave Velocity Data Under the Approximation of 2nd Rank Tensor
Louis, L.; David, C.; Robion, P.
2003-12-01
From diagenesis to tectonic stress induced deformation, rock microstructures always present some anisotropy associated with a preferential orientation, shape or spatial arrangement of its constituents. Considering the consequences this anisotropy has on directional transport and mechanical properties, as the geological history it carries, its 3D characterisation has received a particular attention in numerous works. A fast and simple way to give an overall estimation of the microstructural state of a rock sample is the determination of some physical property fabrics, provided that one is able to assign the measured anisotropies to one or more microstructural features. In non porous metamorphic and igneous rocks that often present a strong textural anisotropy, the relations between shape or lattice preferred orientation and acoustic or magnetic properties are quite well established. However, this is not the case for weakly anisotropic granular media in which the recognition of a microstructural anisotropy implies a statistical analysis on thin sections. In this latter case, anisotropy of magnetic susceptibility (AMS) has been intensively used in structural studies, providing a mid-scale (cm) tool to infer different stages of deformation depending on the position in the studied structure, but leading to an unresolved interpretation problem in terms of microstructures since the origin of the magnetic signal rarely fits a directly observable feature. In the work that will be presented, we propose to complete the classical AMS approach with the estimation of P-wave velocity anisotropies (APV), assuming that this property, like the magnetic susceptibility, supports also a tensorial notation as a first order approximation. Through a careful study of samples retrieved from different deformed structures, we show that P-wave velocities reveal a strong sensitivity to all observable anisotropic microstructural features, which is used to highlight evidences for location-dependence of grain-scale fabrics.
19. A Pseudo Ramp Manager Workstation for the Laboratory Development of Airline-ATC Collaborative Arrival Planning Tools
NASA Technical Reports Server (NTRS)
Zelenka, Richard; Mathan, Santosh; Quinn, Cheryl; Dorsky, Susan
1998-01-01
The continued expansion of air traffic and air carrier economic pressures are demanding changes to air traffic management and the relationship between the air traffic control service provider and the system user. Such pressures have motivated efforts to increase the flexibility of air traffic management operations and allow collaboration between the service provider and system user. The government/industry "free-flight" initiative, whose ultimate vision is to allow users to select their own path and speed in real-time with air traffic control imposing restrictions only when necessary, is the most visible of such efforts. Shared decision making and collaboration between system users and service providers has been identified as providing benefits necessary to support subsequent phases of free-flight. In the terminal arrival phase of flight, many restrictions and a high degree of control are placed on system users without regard for individual user operational preferences. Commonly imposed airborne delays applied to arriving aircraft on a first-come, first-serve basis do not allow the system users to prioritize for late arrivals or to economically optimize their arrival sequence. Service provider/system user collaborative arrival planning decision support tools are being developed to allow such priorities. Airline preferences are most important to an airline's "hub operation," where off-schedule arrival aircraft are common and sought to be corrected, as they cause serious airport ramp difficulties and result in large airline operational inefficiencies. In this work, a simulated ramp manager workstation is described which was developed to support the laboratory simulation development of collaborative arrival planning tools. These tools are derived from the NASA Center/TRACON Automation System (CTAS). The workstation presents a "gant chart" type display of arriving and departing aircraft sorted by airport gate, as typically used by "hub and spoke" air carriers in their airport ramp towers. This Pseudo Ramp Manager is a critical element for proper laboratory development of future service provider/system user cooperative ATM decision support tools.
20. 19 CFR 4.4 - Panama Canal; report of arrival required.
Code of Federal Regulations, 2014 CFR
2014-04-01
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https://cs.stackexchange.com/tags/real-numbers/hot | People who code: we want your input. Take the Survey
# Tag Info
37
Sage is an open source computer algebra system. Let's see if it can handle your basic example: sage: sqrt(3) * (4/sqrt(3) - sqrt(3)) 1 What is happening under the hood? Sage is storing everything as a symbolic expression, which it is able to manipulate and simplify using some basic rules. Here is another example: sage: 1 + exp(pi*i) 0 So sage can also ...
22
There is no way to represent all real numbers without errors if each number is to have a finite representation. There are uncountably many real numbers but only countably many finite strings of 1's and 0's that you could use to represent them with.
20
It all depends what you want to do. For example, what you show is a great way of representing rational numbers. But it still can't represent something like $\pi$ or $e$ perfectly. In fact, many languages such as Haskell and Scheme have built in support for rational numbers, storing them in the form $\frac{a}{b}$ where $a,b$ are integers. The main reason ...
18
Computer algebra is a huge area, probably at least a semester-long university-level course to get most of the basics. However, I think we can cover some of the flavour of it here. Your case is the easy case, because it is entirely within the language of algebraic numbers (i.e. roots of polynomials), and manipulating polynomials is really the foundation of ...
9
Any machine model in which a machine can be described by a string over a fixed alphabet can only compute countably many things. Since there are uncountably many real numbers, all of these machine models fail to compute almost all real numbers. In fact, the alphabet need not be fixed. It is enough that the alphabet is taken from some countable set of finite ...
8
A real number cannot be input into a Turing machine, since it is an infinite object. There are various models for providing a Turing machine with oracle access to real numbers, but these are by definition computable. You could imagine a Turing machine given a ZFC definition of a real number, and in that case it's undecidable. For example, given a Turing ...
8
Yes. There are. There is the real-RAM/BSS model mentioned in the other answer. The model has some issues and AFAIK there is not much research activity about it. Arguably, it is not a realistic model of computation. The more active notion of real computability is that of higher type computation model. The basic idea is that you define complexity for higher ...
8
The model you describe is known as the Blum-Shub-Smale (BSS) model (also Real RAM model) and indeed used to define complexity classes. Some interesting problems in this domain are the classes $P_R$, $NP_R$, and of course the question of whether $P_R$ = $NP_R$. By $P_R$ we mean the problem is polynomially decidable, $NP_R$ is the problem is polynomially ...
8
Yes, Rice's theorem for reals holds in every reasonable version of computable reals. I will first prove a certain theorem and a corollary, and explain what it has to do with computability later. Theorem: Suppose $p : \mathbb{R} \to \{0,1\}$ is a map and $a, b \in \mathbb{R}$ two reals such that $p(a) = 0$ and $p(b) = 1$. Then there exists a Cauchy sequence ...
7
Your idea does not work because a number represented in base $b$ with mantissa $m$ and exponent $e$ is the rational number $b \cdot m^{-e}$, thus your representation works precisely for rational numbers and no others. You cannot represent $\sqrt{2}$ for instance. There is a whole branch of computable mathematics which deals with exact real arithmetic. Many ...
7
There are many effective Rational Number implementations but one that has been proposed many times and can even handle some irrationals quite well is Continued Fractions. Quote from Continued Fractions by Darren C. Collins: Theorem 5-1. - The continued fraction expression of a real number is finite if and only if the real number is rational. Quote ...
7
Type-2 Turing machines are not more powerful than ordinary Turing machines in the sense that any map $\mathbb{N} \to \mathbb{N}$ that can be computed by a type-2 machine can also be computed by an ordinary machine. To see this, suppose a type-2 Turing machine $T$ computes a function $f : \mathbb{N} \to \mathbb{N}$. We can convert $T$ to an ordinary machine ...
6
Let's assume that the numbers $a_1,\ldots,a_n$ are integers, so that the problem is in NP for any fixed $f$. We construct a polynomial $f$ so that the problem is NP-complete, by reduction from vertex cover in cubic graphs ($3$-regular graphs). Let the instance of cubic vertex cover consist of a cubic graph $G=(V,E)$ and an integer $m$, and let $|V| = n$. ...
6
Here is the question: You are given a list of length $n+1$ which contains the numbers $1,\ldots,n$, one of them appearing twice (and the rest appearing once). Find the number which appears twice. The sum of numbers from $1$ to $n$ is $\frac{n(n+1)}{2}$, so if you subtract that from the sum of the list you get the number appearing twice.
5
There are a number of "exact real" suggestions in the comments (e.g. continued fractions, linear fractional transformations, etc). The typical catch is that while you can compute answers to a formula, equality is often undecidable. However, if you're just interested in algebraic numbers, then you're in luck: The theory of real closed fields is complete, o-...
5
In a nutshell: Printing a random non-computable real is a meaningless task, for precise technical reasons. The meaningful problem is to print non-computable numbers precisely identified by some unique property. But these cannot be printed by any program precisely because they are not computable. Using randomness in the hope of printing by chance the ...
5
Turing machines, in the classical sense, decide languages of finite strings over finite alphabets. Your logical language has uncountably many constant symbols so you can't even write down all the formulas as strings, let alone ask a Turing machine to decide things about the collection of formulas.
5
The continued fraction algorithm is easy enough to implement. The first step is to compute the continued fraction of the input $x = [c_0;c_1,\ldots]$. You start with $x_0 = x$, and use the recurrence $c_i = \lfloor x_i \rfloor$, $x_{i+1} = 1/(x_i - c_i)$. You stop when $x_i - c_i$ is "small enough". The next step is to compute the convergent of the continued ...
5
We can compute $$f(\theta) = -N\log (2\pi)-\frac{1}{2}\sum_{i=1}^N (\langle x_i,\theta \rangle -y_i)^2.$$ Expanding this out, we get that $f(\theta)$ is some quadratic form: $$f(\theta) = \theta' A \theta + v'\theta + C,$$ where $A$ is symmetric. The next step is to get rid of the linear term. Let $\theta = \psi + \epsilon$. Then $$\theta' A \theta + \... 4 If you use the operators \{+,-,\times,/\} (i.e., you don't included the power operator), then all of your problems are likely decidable. Testing equality with zero For instance, let's consider L = \mathbb{Z} \cup \{\pi\}. Then you can treat \pi as a formal symbol, so that each leaf is a polynomial in \mathbb{Z}[\pi] (e.g., the integer 5 is the ... 4 This is a rather tricky question! As you seem to understand, the real issue is the presence of \hat{}. It is intimately related to a well known conjecture: Schanuel's conjecture, which states that, essentially, there are no non-trivial algebraic relationships between \pi and e. The (expected) positive answer to this conjecture would give you a ... 4 The set of higher-order primitive recursive reals is essentially the class of functions \mathbb{N}\rightarrow\mathbb{N} which can be represented by a term \mathrm{Nat}\rightarrow\mathrm{Nat} in Gödel's system T. Since every such function is total, and every well-typed term in the system can be enumerated effectively, there is a relatively easy proof by ... 4 There are several issues with your question but perhaps I can clarify some issues. First off you assume f(1) = 1.999... and also that no x \in \mathbb{N} exists such that f(x) = 2 but that's a contradiction in terms because 1.999... = 2 and thus f(1) = 2. Why does 1.999... = 2? Well there's an easy answer but not fulfilling answer and a more ... 3 Consider the following reasonable definition for a Turing machine computing an irrational number in [0,1]. A Turing machine computes an irrational r \in [0,1] if, on input n, it outputs the first n digits (after the decimal) of the binary representation of r. One can think of many extensions of this definition for probabilistic Turing machines. ... 3 You are looking for an optimal 1-dimensional k-means algorithm. The k-means objective function for partitioning the data x_1, \ldots, x_n into k sets S = \{S_1, \ldots, S_k\}.$$ \sum\limits_{i=1}^k \sum\limits_{x \in S_i}\lVert x - \mu_i \rVert^2 where $\mu_i$ is the mean of $S_i$ [1]. You can apply a dynamic programming algorithm to the ...
3
It's pretty clearly an algorithm according to my definition in the linked question. I think your real question is "what is the problem, if any, for which this algorithm is correct?" The answer would be something like "given some stuff and a number of iterations, output a value satisfying some condition with an accuracy related to the iteration count."
3
Original formulation (Originally, the OP was interested in the minimum absolute difference rather than the minimum non-zero absolute difference.) You are asking two different questions. For the first, consider the restricted version in which all numbers are rational, and the decision variant in which the problem is to decide whether your expression is at ...
3
Check this out! http://coq.io/opam/coq-markov.8.5.0.html. A library for Markov's inequality built on mathematical probability theory.
3
You can run any standard quantum algorithm on a real-amplitude quantum computer with one additional qubit and only constant-factor slowdown (or perhaps linear-factor slowdown considering loss of parallelism) by replacing each $a{+}bi$ in your unitary matrices by $\big(\begin{smallmatrix}a&-b\\b&a\end{smallmatrix}\big)$. Likewise, you can simulate a ...
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http://math.stackexchange.com/questions/7926/if-v-is-a-vector-space-that-what-is-v-mathbbn/7930 | # If $V$ is a vector space, that what is $V^\mathbb{N}$?
Notation question (I believe the notes that I'm reading uses pretty common notation):
Let $V$ be a vector space over a field $K$. What is $V^\mathbb{N}$? Is it a vector space of infinite dimensions? What are the elements of $V^\mathbb{N}$? Are they infinite length tuples?
-
BTW I'd have preferred to ask this question on chat.math.stackexchange.com but it's not setup yet. – user2468 Oct 26 '10 at 15:47
In my opinion, this notation is ambiguous (edit: but maybe I'm wrong). It could mean two things: it could mean the space of functions $\mathbb{N} \to V$, which is a vector space in the obvious way. This is the countable product in the category of vector spaces. This vector space is very large; in particular, it has uncountable dimension and it is not spanned by the functions $e_i$ which are equal to $1$ at $i$ and equal to $0$ elsewhere.
Or it could mean the space of functions $\mathbb{N} \to V$ which are zero except at finitely many places, which is also a vector space in the obvious way, but countable-dimensional, and this is the vector space spanned by the $e_i$. This is the countable coproduct in the category of vector spaces. (Note that it is not necessary to distinguish between finite products and finite coproducts because they are the same.)
If I had to guess, I would guess that it means the former. Can you give a link to the notes? It might be possible to figure out which one is meant from context.
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Unfortunately the notes are under protected access within my campus :[ (edit:oops return) Thanks. I check both function spaces and infer which is consistent with the notes. – user2468 Oct 26 '10 at 15:42
I would guess the former too. Most of the time I see the notation $V^\mathbb{N}$ it means "the space of sequences taking values in $V$". – Willie Wong Oct 26 '10 at 15:44
@Qiaochu: I don't think $V^{\mathbb{N}}$ is used for the coproduct, though I have seen $V^{(\mathbb{N})}$ for the elements of $V^{\mathbb{N}}$ of finite support... – Arturo Magidin Oct 26 '10 at 15:59
@Qiaochu: Could you elaborate on why the former has uncountable dimension? – Rahul Oct 26 '10 at 18:25
@Arturo: Thanks for the link. I'm not very well-versed in infinite-dimensional vector spaces, so it will take me a while to digest that proof. @Qiaochu: Ah, I see; I was forgetting that the span is composed of linear combinations, which by definition involve only finitely many vectors. – Rahul Oct 26 '10 at 23:04
It would be the vector space consisting of an infinite product V × V × ... of copies of V.
More generally: for two sets A and B, AB often denotes the set of functions f : B → A. (The only exception I'm aware of is when the sets A and B happen to be ordinals, in set theory; then a different notion of exponentiation is often used.)
How are these two concepts related? Well: as a vector space, V is also a set of vectors. And so a function f : ℕ → V is essentially a block-vector description of a vector v = (f(0), f(1), ...) ∈ V × V × ... .
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surely in the beginning of the second paragraph you meant $f:B\to A$. – Willie Wong Oct 26 '10 at 15:48
@Willie Wong: that's right, silly mistake. – Niel de Beaudrap Oct 26 '10 at 15:50
I'd think of it as the set of sequences of elements of $V$, i.e.
$$V^\mathbb{N} = \prod_{n=1}^\infty V.$$
But I don't think there is a really nice description. In the case where $V$ is finite-dimensional, it'd just be $K^\mathbb{N}$ in a clever (and non-canonically isomorphic) disguise, but if $V$ were to be infinite-dimensional, $V^\mathbb{N}$ could be rather ugly. E.g. $\ell_1^\mathbb{N}$: sequences of absolutely summable sequences. Then a sequence of sequences would converge to a sequence iff it converged coordinatewise. Complicated and very confusing.
Following Munkres' "Topology", I prefer to use $V^\infty$ for set of sequences in $V$ for which only finitely many elements are nonzero, i.e.
$$V^\infty = \bigoplus_{n=1}^\infty V = \left\lbrace (v_n) \in V^\mathbb{N} \;{\large\mid}\; \text{v_n = 0 from some index onwards}\right\rbrace.$$
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https://jd2718.org/2007/04/02/puzzle-one-over-one-plus-methods-of-solution/ | This is the place to offer methods of solutions for the puzzle below:
What is the value of $\frac{1}{1+\frac{1}{1 + \frac{1}{1 + \dotsb}}}$ ?
A month ago Dave Marain ran a discussion of $\sqrt{2 + \sqrt{2 + \sqrt{2 + \dotsb}}}$ over here.
I know this one has been done many many times before. But he generated a nice discussion.
There are also places for:
What makes these two problems so similar?
April 3, 2007 pm30 9:48 pm 9:48 pm
$\sqrt{2 + \sqrt{2 + \sqrt{2 + \dotsb}}}$
First examine what this ‘object’ is. It looks a like a sequence,
or better, the limit of the sequence.
The sequence can be described by:
$a_1 = b \hspace{1cm}\mathrm{(initial value)}$
$a_2 = \sqrt{2+a_1}$
$a_3 = \sqrt{2+a_2} = \sqrt{2+ \sqrt{2+a_1}}$
In general:
$a_{n+1}= \sqrt{2+ a_{n}}$
If the limit exists, then $a_{n}$ and $a_{n+1}$ have the same limit.
Thus, $a_{n}=a_{n+1}=B$, where $B$ is the limit of the sequence.
Pluggin this into the equation
$a_{n+1}= \sqrt{2+ a_{n}}$
yields: $B = \sqrt{2 + B}$
$B^2-B-2=0$
Solving for B yields (B>0):
$B = 2$.
Of course, one has to prove the several steps.
April 3, 2007 pm30 10:00 pm 10:00 pm
Correction for my post above:
If the limit exists, then $a_{n}$ and $a_{n+1}$ have the same limit. This can be written as
$\rm{lim} a_{n} = B$ and $\rm{lim} a_{n+1} = B$
I forgot to write $\rm{lim}$ in my former post.
———–
Now, I think I know how this sequence was generated:
$2 = \sqrt{2+2}$
Plugging this into the right hand side yields:
$2 = \sqrt{2+ \sqrt{2+2}}$
and so on…
April 3, 2007 pm30 10:20 pm 10:20 pm
I just figured out how such a sequence looks for 3 (this is fun):
$3 = \sqrt{9}= \sqrt{6+3}$
$= \sqrt{ 6+ \sqrt{6+3} }$
$= \sqrt{ 6+ \sqrt{ 6 + \sqrt{ 6 + 3 }}}$
$latex = \sqrt{ 6 + \sqrt{ 6 + \sqrt{ 6 + \dotsb}}}$
April 3, 2007 pm30 11:17 pm 11:17 pm
$\frac{1}{1+\frac{1}{1 + \frac{1}{1 + \dotsb}}}$
This can be analyzed in a similar way.
The ‘object’ is the limit of a sequence:
$a_{1} = b (\mathrm{initial value})$
$a_{2} = 1+ \frac{1}{a_{1}}$
$a_{3} = 1 + \frac{1}{a_{2}} = 1 + \frac{1}{1+ \frac{1}{a_{1}}}$
In general:
$a_{n+1} = 1 + \frac{1}{a_{n}}$
If we assume that the sequence $a_{n}$ converges, then
$a_{n}$ and $a_{n+1}$ have the same limit. This yields
$B = 1 + \frac{1}{B}$, where B is the limit of the sequence.
It follows:
$B^2-B-1 = 0$
Solving for B yields (B>0):
$B = \frac{1}{2}(\sqrt{5}+1)$
$\frac{1}{2} \left(\sqrt{5}+1 \right) = \frac{1}{2} \left(\sqrt{5}+1 \right) + 1 - 1$
$= 1+ \frac{1}{2} \left(\sqrt{5}+1 \right) -1$
$= 1+ \frac{\sqrt{5}-1}{2}$
$= 1+ \frac{5-1}{2(\sqrt{5}+1)}$
$= 1+ \frac{4}{2(\sqrt{5}+1)}$
$= 1+ \frac{2}{\sqrt{5}+1}$
$= 1+ \frac{1}{\frac{1}{2}(\sqrt{5}+1)}$
The tactic is obvious, in the first step a 1 is added because we want to have the 1 + 1/(1+/…) term. The remaining task is to manipulate the term after the 1 in such a way, that
$\frac{1}{2} \left(\sqrt{5}+1 \right)$
appears again.
April 3, 2007 pm30 11:26 pm 11:26 pm
I just noticed that I calculated the value of
$1+\frac{1}{1+\frac{1}{1 + \frac{1}{1 + \dotsb}}}$
$\frac{1}{1+\frac{1}{1 + \frac{1}{1 + \dotsb}}}$
Thus, the limit of
$\frac{1}{1+\frac{1}{1 + \frac{1}{1 + \dotsb}}}$
is
$\frac{1}{2}(\sqrt{5}-1)$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 44, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9350156784057617, "perplexity": 880.1249367995355}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038087714.38/warc/CC-MAIN-20210415160727-20210415190727-00475.warc.gz"} |
https://artofproblemsolving.com/wiki/index.php?title=1993_AHSME_Problems/Problem_23&oldid=86182 | # 1993 AHSME Problems/Problem 23
## Problem
Points and are on a circle of diameter , and is on diameter
If and , then
## Solution
We have all the angles we need, but most obviously, we see that right angle in triangle .
Note also that angle is 6 degrees, so length because the diameter, , is 1.
Now, we can concentrate on triangle (after all, now we can decipher all angles easily and use Law of Sines).
We get:
That's equal to
Therefore, our answer is equal to:
Note that , and don't accidentally put because you thought 1/sin was sec!
1993 AHSME (Problems • Answer Key • Resources) Preceded byProblem 22 Followed byProblem 24 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 • 26 • 27 • 28 • 29 • 30 All AHSME Problems and Solutions | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9200745224952698, "perplexity": 5562.639371382968}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964358673.74/warc/CC-MAIN-20211128224316-20211129014316-00290.warc.gz"} |
https://www.physicsforums.com/threads/rlc-circuit-with-damping-questions.142374/ | # Homework Help: RLC Circuit with damping questions
1. Nov 5, 2006
### totallydesperate
I have an RLC Circuit. I've changed the resistors 3 times to give me a case of overdamping, underdamping, and critical damping. In taking my data (this was a long long time ago) I apparently missed taking measurements of current. I'm trying to solve the three differential equations to make a "predicted results" graph. To do this, I need initial conditions V0, which I have, and I0, which I should have. Is there any way besides redoing my experiment to determine what the current at t=0 would be? If so, what other information do you need from me to explain it to me?
2. Nov 5, 2006
### ultimateguy
If you know the value of the resistances and the voltage, then technically you should be able to calculate the current using the Kirchoff law. Even so, keep in mind that calculated values are often a bit different from measured values due to uncertainties. If you're using a calculated value for current when you were supposed to use a measured one, it kind of misses the point. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9426530599594116, "perplexity": 550.3337252503062}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676592875.98/warc/CC-MAIN-20180722002753-20180722022753-00371.warc.gz"} |
http://www.math-only-math.com/worksheet-on-area-and-perimeter-of-rectangles.html | # Worksheet on Area and Perimeter of Rectangles
Recall the topic and practice the math worksheet on area and perimeter of rectangles. Students can practice the questions on area of rectangles and perimeter of rectangles.
1. Find the area and perimeter of the following rectangles whose dimensions are:
(a) length = 17 m breadth = 13 m
(b) length = 6.9 cm breadth = 5.1 cm
(c) length = 5 m breadth = 32 dm
(d) length = 9 hm breadth = 7 dam
2.The perimeter of a rectangle is 230 cm. If the length of the rectangle is 70 cm, find its breadth and area.
3. The area of a rectangle is 96 cm². If the breadth of the rectangle is 8 cm, find its length and perimeter.
4. How many tiles whose length and breadth are 13 cm and 7 cm respectively are needed to cover a rectangular region whose length and breadth are 520 cm and 140 cm?
5. Find the cost of tiling a rectangular plot of land 300 m long and 150 m wide at the rate of $6 per hundred square m. 6. If it costs$1600 to fence a rectangular park of length 20 m at the rate of $25 per m², find the breadth of the park and its perimeter. Also, find the area of the field. 7. How many rectangles can be drawn with 38 cm as perimeter? Also, find the dimensions of the rectangle whose area will be maximum. 8. The length of a rectangular wooden board is thrice its width. If the width of the board is 120 cm, find the cost of framing it at the rate of$5 for 20 cm.
Answers for worksheet on area and perimeter of rectangles are given below to check the exact answers of the above questions.
1. (a) 221m², 60m
(b) 35.19 m², 24m
(c) 1600 dm², 164 dm
(d) 630 dam², 194 dam².
2. 45 cm, 3150 cm²
3. 12 cm, 40 cm
4. 800 tiles
5. $2700 6. b =12 m, P = 64 m, A = 240 m² 7. 9 if l, b ∈ W max area 90 cm², l, b = 10, 9 8.$240
Mensuration - Worksheets
Worksheet on Area and Perimeter of Rectangles
Worksheet on Area and Perimeter of Squares
Worksheet on Area of the Path
Worksheet on Circumference and Area of Circle
Worksheet on Area and Perimeter of Triangle | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5727918744087219, "perplexity": 1657.937464407328}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560281450.93/warc/CC-MAIN-20170116095121-00216-ip-10-171-10-70.ec2.internal.warc.gz"} |
http://www.lmfdb.org/Lattice/3.758.1516.19.10 | # Properties
Label 3.758.1516.19.10 Class number 19 Dimension 3 Determinant 758 Level 1516
# Learn more about
## Lattice Invariants
Dimension:$3$
Determinant:$758$
Level:$1516$
Label:$3.758.1516.19.10$
Density:$0.152143711484287999918659009107\dots$
Group order:$2$
Hermite number:$0.438702648315186715273823555310\dots$
Minimal vector length:$4$
Kissing Number:$2$
Normalized minimal vectors: $(1, 0, 0)$
Download this vector for gp, magma, sage
## Theta Series
$1$ $\mathstrut +\mathstrut 2q^{4}$ $\mathstrut +\mathstrut 2q^{10}$ $\mathstrut +\mathstrut 2q^{12}$ $\mathstrut +\mathstrut 4q^{16}$ $\mathstrut +\mathstrut O(q^{21})$
## Gram Matrix
$\left(\begin{array}{rrr} 4 & 1 & 1 \\ 1 & 10 & 5 \\ 1 & 5 & 22 \end{array}\right)$
## Genus Structure
Class number: $19$ Genus representatives: $\left(\begin{array}{rrr} 4 & 1 & 1 \\ 1 & 10 & 5 \\ 1 & 5 & 22 \end{array}\right)$, $\left(\begin{array}{rrr} 4 & 1 & 1 \\ 1 & 10 & 2 \\ 1 & 2 & 20 \end{array}\right)$, $\left(\begin{array}{rrr} 8 & -4 & 1 \\ -4 & 10 & -1 \\ 1 & -1 & 12 \end{array}\right)$, $\left(\begin{array}{rrr} 4 & 2 & 1 \\ 2 & 10 & -2 \\ 1 & -2 & 22 \end{array}\right)$, $\left(\begin{array}{rrr} 6 & -3 & -2 \\ -3 & 10 & 3 \\ -2 & 3 & 16 \end{array}\right)$, $\left(\begin{array}{rrr} 4 & 1 & 2 \\ 1 & 6 & 0 \\ 2 & 0 & 34 \end{array}\right)$, $\left(\begin{array}{rrr} 8 & 2 & 1 \\ 2 & 10 & -4 \\ 1 & -4 & 12 \end{array}\right)$, $\left(\begin{array}{rrr} 10 & 4 & 5 \\ 4 & 10 & 0 \\ 5 & 0 & 12 \end{array}\right)$, $\left(\begin{array}{rrr} 2 & -1 & 0 \\ -1 & 10 & 1 \\ 0 & 1 & 40 \end{array}\right)$ ... Download the complete list for gp, magma, sage
## Comments
This lattice appears in the Brandt-Intrau-Schiemann Table of Even Ternary Quadratic Forms. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.43279147148132324, "perplexity": 14275.47949322896}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794870470.67/warc/CC-MAIN-20180527205925-20180527225925-00518.warc.gz"} |
https://motls.blogspot.com/2016/06/ambulance-chasing-is-justifiable.html | ## Sunday, June 19, 2016 ... /////
### Ambulance chasing is a justifiable strategy to search for the truth
As Ben Allanach, a self-described occasional ambulance chaser, described in his 2014 TRF guest blog, ambulance chasers were originally lawyers with fast cars who were (or are) trying to catch an ambulance (or visit a disaster site) because the sick and injured people in them, potential clients who may have a pretty good reason to sue someone and win the lawsuit. For certain reasons, this practice is illegal in the U.S. and Australia.
Analogously, in particle physics, ambulance chasers are people who write many papers about a topic that is hot, especially one ignited by an excess in the experimental data. This activity is thankfully legal.
The phrase "ambulance chasing" is often used pejoratively. It's partly because the "ambulance chasers" may justifiably look a bit immoral and egotistically ambitious. However, most of the time, it is because the accusers are jealous and lazy losers. Needless to say, it often turns out that there are no patients capable of suing in the ambulance which the critics of ambulance chasing view as a vindication. However, this vindication is not a rule.
The probability to find clients is higher in the ambulances. It's similar as the reason why it's a better investment of money to make Arabs strip at the airport than to ask old white grandmothers to do the same – whether or not some politically correct ideologues want to deny this obvious point.
Is it sensible that we see examples of ambulance chasing such as the 400 or so papers about the $750\GeV$ cernette diphoton resonance?
It just happens that in recent 2 days, there were two places in the physics blogosphere that discussed a similar topic:
An exchange between 4gravitons and Giotis
Game of Thrones: 750 GeV edition (Resonaances)
It seems rather clear that much like your humble correspondent, the first page is much more sympathetic to the ambulance chasing episodes than the latter one.
My conservative background and that of a formal theorist make me a natural opponent of ambulance chasers. If I oversimplify this viewpoint, we're solving primarily long-term tasks and it's a symptom of the absence of anchoring when people chase the ambulances. For example, quantum field theory and string theory will almost certainly be with us regardless of some minor episodes and discoveries and that's why we need to understand it better and we should pay too much attention to some "probably" short-lived fads.
However, the more experiment-oriented parts of particle physics – and even the theoretical ones – are sometimes much more dependent on an exciting breakthrough. Some developments may look like short-lived fads at the beginning but they actually turn out to be important in the long run. A subfield suddenly grows, people write lots of papers about it and they may even switch their fields a little bit. Is that wrong? Is it a pathology?
I don't think so.
As Giotis and Tetragraviton agreed in their discussion, the size of the subfields of string theory (or any other portion of physics research) changes with time. The subfields that recently experienced a perceived "breakthrough" grow bigger. Is that immoral?
Not at all.
It simply means that people appreciate that some methods or ideas or questions have been successful or they have demonstrated that they could be a route to learn lots of new truth quickly. And because scientists want to learn as much of the truth as possible, they naturally tend to pick the methods that make this process more efficient. It's common sense. There seem to low-hanging fruits around the breakthroughs and people try to pick them. As they're being picked, the perceived density of the fruits may go down and the "fad" may fade away.
So string phenomenology was producing a huge amount of papers for a few years after some amazing progress took place in that field. Similarly, the AdS/CFT correspondence opened a whole new industry of papers – the papers that study quantum field theories using "holographic" methods. AdS/CFT came from Maldacena's research of formal string theory and the black hole information puzzle. These two interrelated subfields of string theory have actually produced several other subindustries, although smaller than the holographic ones. The word "subindustry" is a more appropriate term than a "minirevolution" for something that the cynics call a "fad", especially when this "fad" continues to grow for 20 years or so.
The ability of formal string theory to produce similar breakthroughts is arguably still being underestimated.
At any rate, a part of the dynamics of the changing relative importance of subfields of fundamental physics – or string theory – is certainly justifiable. I don't want to claim that people study things exactly as much as they should – I have often made it clear that I believe that such deviations from the optimum exist, most recently in the previous short paragraph ;-) – but most critics generally misunderstand how sensible it is for people to be excited about different things at different times. Many critics seemingly believe that they are able to determine how much effort should be spent with every thing (such as A, B, C) even though they don't understand anything about A, B, C. But that's nonsense. You just can't understand how big percentages of time physicists spend with various ideas if you don't know what all of these ideas are.
At Resonaances, Adam Falkowski is basically making fun out of the people who have written many papers about the $750\GeV$ diphoton resonance. With this seemingly hostile attitude to resonances, you may think it's ironic for the blog to be called Resonaances. But maybe the word means Resona-hahaha-ances, i.e. a blog trying to mock resonances.
The top contestants have a similar output as Alessandro Strumia – some 7 papers on the topic and 500 citations. A paper with 10 authors from December 2015 has over 300 citations now. If they had to divide the citations among the co-authors, it wouldn't be too many per co-author.
Clearly, physicists like Strumia are partially engaging in an activity that could be classified as a sport. But is that wrong? I don't think so. Physics is the process of learning the truth. We often imagine theoretical physicists as monks who despise things like sports and by my fundamental instincts, I am close enough to it. But the "learning of the truth" isn't in any strict way incompatible with "sports". They're just independent entities. And sports sometimes do help to find the truth in science.
I would agree with some "much softer and more careful" criticisms of ambulance chasing. For example, in most such situations, the law of diminishing returns applies. The value of many papers usually grows sublinearly with their number which is why most "fads" usually fade away. The value of 7 papers about the resonance is probably smaller than 7 times the value of a single paper about the resonance. First, there is probably some overlap among the papers. Second, even if there is no overlap, many of the "added" papers are probably less interesting because the author knows which of the ideas are the most promising ones, and by writing many papers, he or she probably has to publish the less promising ones, too.
So this activity may inflate the "total number of citations" more quickly than the underlying value of the physical insights. At the end, the number of citations that people like Alessandro Strumia have accumulated may overstate their overall contributions. But they don't really hysterically fight for the opinion that it doesn't. They just do science – and a lot of it. It's up to others who need the number to quantify the contributions.
At the end, I still find it obvious that in average, it's better when a physicist writes 7 papers about a topic than if he writes 2. The results vary and 1 paper is often more valuable than 10,000 other papers. But if one sort of imagines that they're papers at the same level, 7 is better than 2. So it's not reasonable for Falkowski to mock Strumia et al. Needless to say, if the resonance goes away, Falkowski will feel vindicated. If it is confirmed, Falkowski will look sort of stupid.
But even if the resonance (or whatever it is) goes away, we can't be sure about it now. The only way to feel "sure" about it is to assume that no important new physics will ever be found. But if you really believe such a thing, you just shouldn't work in this portion of physics, Dr Falkowski, because by your assumption, your work is worthless.
It is absolutely healthy when the experimental deviations energize the research into some models. You know, a similar research into models takes place even in the absence of excesses. But by Bayes' theorem, the excesses increase the odds that certain models of new physics are right. You can calculate how big this increase is: it is a simple function of the formal $p$-value. If there is just a 0.01% formal probability that the cernette excess is a false positive, it is even justifiable to increase the activity on the models compatible with it by four orders of magnitude. In practice, a much smaller increase takes place. But some increase is undoubtedly justified.
Physicists often say that they're doing the research purely out of their curiosity and passion for the truth. In practice, it's almost never the case. People have personal ambitions and they also want jobs, salaries, grants, and maybe also fame. But that's true in other occupations, too. I don't think it's right to demonize the athletes among particle physicists. They're pretty amazing.
In particle physics, you can have counterparts of ATP and WTA rankings in tennis. Strumia is probably below veterans such as John Ellis. At the end, physics isn't just like tennis so the most important and famous physicists may be – and often are – non-athletes such as physics incarnations of monks. They're rather essential. But the physics athletes do a nontrivial part of the progress, anyway. Attempts to erase one of these whole groups amount to cultural revolutions of Mao's type. You just shouldn't think about such plans. Everyone who is dreaming about a similar cultural revolution surely misunderstands something important about the processes that make science – and the human society or the economy – work.
Whether or not the diphoton resonance is going to be confirmed, it was utterly reasonable and should be appreciated that some people did a lot of work on models that could explain such a deviation. At least, they worked on an exercise that had great chances to be relevant in Nature. But even if it weren't relevant, some of the lessons of this research may be applied in a world without the cernette, too. The experimental deviation has also been a natural source of the excitement and energy for the phenomenologists because many of them clearly do believe in their hearts that this excess could be real.
Incidentally, we may learn whether it's real very soon. In 2016, more than 5 inverse femtobarns have already been recorded by each major LHC detector. So before the end of June, 2016 has already beaten all of 2015. The data needed to decide about the fate of the theory that the cernette exists with the cross section indicated in 2015 have almost certainly been collected. Someone may already know the answer but it hasn't gotten out yet. It may change within days.
Bonus
An example of an activity much less justified than ambulance chasing, from Resonaances
Jason Stanidge said...
It doesn't look good IMO that none of the physicists listed come from leading institutions such as Harvard, Cambridge UK etc. Ah well: when the bump fades as will be soon rumoured by Jester, at least there is the possibility of other bumps in the data to look forward to.
Anonymous said...
Hi Jason Stanidge
are you runouring that the bump is fading away?
Now, this is an example of "trabant chasing with the hope that the trabant will turn into an ambulance". Anonymous has no rational reason to think that Jason Stanidge knows anything about the most recent LHC data. He is trying to push Jason to admit that he is an insider who knows something. And Jason has some probability to reply in a way that suggests that he may know something. But everyone has a nonzero probability to reply in this way. This "signal" would be artificially constructed by the "experimenter", Anonymous, which makes it much less tangible than the actual diphoton excess that was produced by the unique 2015 LHC dataset.
By the way, the comment about the leading institutions is illogical, too. The diphoton resonance has surely been worked on by numerous researchers from Harvard and all other top places, too. Moreover, I find it somewhat bizarre not to count Strumia's affiliation, CERN theory group, among the top places in particle physics. The winners of the ambulance chasing contests may be from other places than the Ivy League but that doesn't show that there's something "not good" about the intense work on currently intriguing experimental signs. You simply can't define the best character of work as whatever is being done at Harvard. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 1, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4861108660697937, "perplexity": 1186.9708823389537}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-04/segments/1547583658702.9/warc/CC-MAIN-20190117041621-20190117063621-00127.warc.gz"} |
https://www.peterkrautzberger.org/0104/ | # Rapid idempotent ultrafilters
Welcome back to the second (and final) part on why strongly summable ultrafilters are rapid.
Why the new title? Well, first, I needed another one (I’ve had too many posts with “Part X” in them, I think). Second, after I proved the results I mentioned last time, I quickly found an additional, somewhat more general observation regarding idempotents.
Here’s the problem with this post though. I want to give the argument. But you know how it is in mathematics: standing on the shoulders of the huddled masses giants and all that. All work relies on established results. In the first post, I gave a lot of “unnecessary” proofs to motivate the story behind the result. In this post, I’ll get to the actual proof and I’m torn, I’m not sure how much to quote and how much to prove. So bear with me and leave comments whenever I screw up.
### Strongly summables are rapid.
Why could this be true? On the one hand, because we already established partial results last time. On the other hand there’s an old result attributed to Pierre Matet which, for now, I can only state in a obfuscated fashion.
Theorem (Matet 87)
If is a strongly summable ultrafilter, then there exists a function “” such that is rapid.
So you see, strongly summable ultrafilters imply the existence of rapid ultrafilters – via a very simple -function.
What’s , you’re asking?
Ah yes, I should talk about
### \max to the Max.
For FS-sets, there is a natural notion of maximum. If you have a bunch of elements summed up, then it makes sense to call the largest summand the maximum. So intuitively, the maximum should simply map each element in the FS-set to the largest generator involved in producing it. This might not appear very well defined but bear with me.
Consider an FS-set, let’s keep calling it . If we’re lucky, there is a unique way to write each as a sum of (or should I write ? indices are hard…). For example, the sequence has this property while fails to have this property (quite badly, I suppose).
It turns out that there’s an easy property to ensure this: the sequence just has to grow quickly.
Proposition (folklore? can be found in Blass, Hindman 87)
If for all , then
In other words, each element in has a unique representation.
[Edit May 22, 2012: modified attribution]
The proof is an easy induction on , using the growth factor to argue that the maximal element of and must be equal.
• If , then follows immediately from the growth assumption.
• Now assume inductively that we’ve proved the claim for smaller sets.
• Let be the maximum of .
• Wlog, .
• Then we must also have – otherwise a contradiction to the assumed equality of both sums.
• But if both and contain , we also have .
• Using our induction hypothesis, we have , hence .
So if we have unique representations of elements in , we can define a function
### Growth, growth, growth and more growth
Unfortunately, we need to tweak this a little bit more. Remember that FS-sets are all about sums. Very often will have . So assuming growth, each have a unique representation in terms of the .
It’s natural to assume that there’s some kind of connection between the representations of . For one thing, we know that if , then . The growth as above does not guarantee the reverse, though (just consider ), and the reverse often simplifies things. Fortunately, all we have to do is improve the growth!
Proposition (Hindman, Blass 87)
If , then if and only if and .
The proof is much like the earlier proof.
• Again, we’re doing an induction on .
• If , then or must be empty and the growth condition does the rest.
• For the inductive step, let .
• Due to the growth condition, must be in .
• But it must also lie in .
• Else .
• But it can’t be in both and .
• Else .
• Wlog
• Th .
• Applying our induction hypothesis to , we get and .
• This in turn gives us (as ) and – as desired.
Why all this trouble? Well, there are many uses for this. For what’s coming below, it simplifies an important calculation. In general, it is extremely important since it allows us to switch from the addition of numbers to the union of disjoint, finite sets. (I don’t know about you, but I find the union operation on disjoint sets much easier to comprehend.)
Corollary
If has growth as above, then if we ever have (and we will), then, assuming , we have .
In particular, if , then .
### Strongly summable ultrafitlers are rapid – the proof.
Anyway, let’s get back to where we started. First, we should make a connection to strongly summable ultrafilters.
Lemma (Blass, Hindman 87)
If is strongly summable, then has a base of FS-sets whose sequences satisfy the growth condition (the stronger one with factor , of course).
This is a great lemma (though maybe not a true lemma) and the reason why I spend so much time above talking about growth conditions – it comes in handy in many situations and really tells us something about strongly summable ultrafilters and the sets they contain. The proof, however, is weird so I’ll skip it (unless you insist in the comments).
And now it makes sense to state the initial theorem.
Theorem (Matet, 87 / Blass, Hindman 87)
Let be a strongly summable ultrafilter and with growth (or just unique representations); fix the -function for as above. Then is a rapid P-point.
[Edit on May 21, 2012: I rephrased the theorem to improve clarity – thanks to the comment-by-email who suggested it!]
You can skip the proof if you like because it’s not important to us (and I’m cheating a little on the important part, rapidity). But I find the argument appealing and since I’ve had to go through all the trouble to introduce the growth condition and so forth, I think I might as well include this, too. It’s a typical proof for strongly summable ultrafilters – just write down a good partition and let it do the work for you.
• Fix .
• We will prove that is either constant on a set in or it is finite-to-one.
• Pick any with .
• Let be the minimum function analogous to .
• Now partition into
and
• Our strongly sumable ultrafilter will give us (with the usual growth condition) included in one of these two parts.
• If is included in the first part, then is bounded on . (In particular, is constant on a set in .)
• Consider and pick any other .
• Due to the growth condition, we have and reversely .
• In particular, .
• So is bounded on and we find a
• If is included in the second part, then is finite-to-one on .
• Consider some point in the image of , say .
• If for some we have , then by our assumption.
• But how many can there be with ? At most -many!
• The will have pairwise distinct minima. Why?
• Remember that for we naturally have .
• By the growth condition of the , we know that and are sums of disjoint sets of ’s.
• In particular, their minima will differ!
• Therefore, is finite-to-one.
• And now the cheating: the last argument shows that is at most size . To be able to make any finite-to-one function an -to-one function is, in fact, equivalent to being a rapid ultrafilter. It’s a nice exercise, but feel free to insist in the comments.
This theorem is the reason I originally (back in 2010, in my conversations with Jana at BLAST) thought there’s a chance that all strongly summable ultrafilters are rapid. First, is a finite-to-one function. It’s an old, probably folklore result (cf. Miller, 1980) that the finite-to-one image of a rapid ultrafilter is again rapid. Now the reverse is not true but our function is so easy that it’s possible to prove this.
[Edit May 22, 2012: modified attribution]
Theorem (Krautzberger (yep, this is it))
If is strongly summable, then is rapid.
Here’s the gist: the trick is simple: speed up functions by and let that sped-up function be dominated in the rapid image. Then we pick an FS-set in our strongly summable ultrafilter that witnesses this domination, in particular, it’s generating sequence will dominate that sped-up function. Finally, just as in our initial observations in the first post, the FS-set will still grow fast enough to dominate the original function.
• By Matet’s theorem pick such that is rapid.
• Now pick any .
• We may assume that is strictly monotone (that’s all the functions we need to dominate).
• By Matet’s theorem we can find a set that dominates .
• Now fix such that ; for simplicity, we can assume that the also satisfy the growth condition.
• Then dominates .
• Let . We’ll show that .
• Pick the maximal .
• So , i.e., we only need to find out how large is.
• Of course, .
• Now , so is greater or equal to the -th element of .
• Since the dominates , this gives us .
• By ’s monotonicity, ,
• But the set contains exactly -many elements, i.e., less than -many elements – precisely as desired.
Whew, ok. That’s done.
### Jana asked one more question
After I got around to writing my argument up properly after the conference, Jana asked me whether there are could be other rapid idempotent ultrafilters. In particular, could there be so-called minimal idempotents which are rapid? This, again, sounded rather drastic to me. Minimal idempotents have extremely rich algebraic properties, in particular, any set in them is central and thus all versions of the Central Sets Theorem hold for such sets (as opposed to FS-sets where no FS-set with the growth condition satisfies even the simplest Central Sets Theorem).
But, of course, by now I was skeptical of my own skepticism.
To understand this question, we have to go back to strongly summable ultafilters for a second. Due to Matet’s result, we know that the existence of stongly summable ultrafilters imply the existence of rapid P-points. In particular, the existence of strongly summable ultrafilters cannot be proved using ZFC alone.
But speaking of P-points and rapidity, it is a famous open problems whether there is a model with neither P-points nor Q-points. We can achieve a model without P-points and a model without Q-points, but incidentally not both. (As a taste of the problem: the continuum must at least be in such a model.)
On top of that, there exists a model without rapid ultrafilters (hence without Q-points), but disturbingly, afaik, nobody has a model without Q-points but with rapid ultrafilters! In other words, all known models without Q-points are without rapid ultrafilters (but with P-points).
Also, as a consequence of the big open question, any known model without P-points has Q-points, hence rapid ultrafilters.
What I’m trying to say is that Jana’s question leads to a whole bunch of interesting and classical open problems. So it was very much worth thinking about.
If there are other rapid idempotents, how do we get them? It turns out we can get the possibly strongest positive answer to this question.
Theorem (Krautzberger (yippie, another micro-contribution))
If there exists a rapid ultrafilter, then there exist rapid idempotent ultrafilters. In fact, then there exists a whole closed left ideal of rapid ultrafilters, in particular there are minimal idempotents which are rapid.
As it turns out this follows easily from two well-known results on rapid ultrafilters which give us the following:
Proposition
If is rapid, any ultrafilter, then is rapid.
• Since is rapid, the tensor product is rapid (this can be found in Miller, 1980).
• Also, the finite-to-one image of a rapid ultrafilter is rapid (again, see Miller, 1980).
• But and addition is a finite-to-one map.
• Hence is rapid.
Then the proof of the theorem is as follows:
• Let be a rapid ultrafilter.
• Then is a closed left ideal containing only rapid ultrafilters.
• This is a closed left ideal since is a continuous map.
• If is any ultrafilter, then is rapid.
• Every closed left ideal contains (by compactness) a minimal left ideal which in turn contains a minimal idempotent (that’s one way of defining them, actually).
This theorem seems very strong to me. If I have one rapid, I have an entire closed left ideal of rapid ultrafilters – that’s one of the crucial structures in Algebra in the Stone–Čech compactification!
If you happen to have strongly summable ultrafilters, this gives an even nicer observation. You see, the definition of minimal idempotent can be given in terms of minimality in a certain partial order on the idempotents, namely
There are two obvious related orders, iff , and (guess how it’s defined). It’s an easy exercise (really), that minimality in either partial order is minimality in all others.
An old result is that strongly summable ultrafilters are right maximal (in fact, strongly right maximal: has only one solution, ).
This means that assuming we have strongly summable ultrafilters, then we have a “full spectrum” of rapid idempotents – from right maximal all the way to (right) minimal.
Well, and that’s all folks. I hope you enjoyed my little experiment as much as I have. I’ll certainly write a follow-up post when I’ve decided where to put a fixed copy of this.
Please let me know if you find any errors in the proof and, more importantly, if you think I should clarify certain parts. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9877647757530212, "perplexity": 882.1626330280505}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676593051.79/warc/CC-MAIN-20180722061341-20180722081341-00092.warc.gz"} |
https://arxiv.org/abs/0908.1509 | math.PR
# Title:Sharp heat kernel estimates for relativistic stable processes in open sets
Abstract: In this paper, we establish sharp two-sided estimates for the transition densities of relativistic stable processes [i.e., for the heat kernels of the operators $m-(m^{2/\alpha}-\Delta)^{\alpha/2}$] in $C^{1,1}$ open sets. Here $m>0$ and $\alpha\in(0,2)$. The estimates are uniform in $m\in(0,M]$ for each fixed $M>0$. Letting $m\downarrow0$, we recover the Dirichlet heat kernel estimates for $\Delta^{\alpha/2}:=-(-\Delta)^{\alpha/2}$ in $C^{1,1}$ open sets obtained in [14]. Sharp two-sided estimates are also obtained for Green functions of relativistic stable processes in bounded $C^{1,1}$ open sets.
Comments: Published in at this http URL the Annals of Probability (this http URL) by the Institute of Mathematical Statistics (this http URL) Subjects: Probability (math.PR); Mathematical Physics (math-ph) Journal reference: Annals of Probability 2012, Vol. 40, No. 1, 213-244 DOI: 10.1214/10-AOP611 Report number: IMS-AOP-AOP611 Cite as: arXiv:0908.1509 [math.PR] (or arXiv:0908.1509v2 [math.PR] for this version)
## Submission history
From: Zhen-Qing Chen [view email] [via VTEX proxy]
[v1] Tue, 11 Aug 2009 19:48:29 UTC (31 KB)
[v2] Wed, 26 Sep 2012 09:15:50 UTC (53 KB) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6493779420852661, "perplexity": 2196.0216282783895}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560628001138.93/warc/CC-MAIN-20190627115818-20190627141818-00392.warc.gz"} |
https://space.stackexchange.com/questions/5073/standing-at-the-top-of-a-space-elevator-would-up-be-towards-the-earth | # Standing at the top of a space elevator would 'up' be towards the Earth?
If I rode a space elevator to the top, assuming only natural forces apply, would the Earth be over my head or under my feet? If it was over my head how is that possible?
Above geosynchronous orbit, so called centrifugal force exceeds force of gravity. So earth would be above you.
Centrifugal acceleration (actually just inertia in a rotating frame) is $\omega^2r$ where ω is angular velocity in radians.
Acceleration from gravity is $GM_e/r^2$ where $M_e$ is mass of earth and r is distance from earth's center.
You will find that $GM_e/r^2$ and $\omega^2r$ exactly cancel at geosynchronous altitude. Above geosynchronous $\omega^2r$ exceeds $GM_e/r^2$. You will weigh more as you move further beyond geosynchronous height.
If my arithmetic is right, you wouldn't feel a full g until you're about 1.8 million kilometers from earth's center.
• In your answer to Where could we build a space elevator today (2014)? you give an altitude of 142,772 Km for the top of an Earth Elevator (no counterweight), so it would seem that the you should have a full G there. Is your math wrong, or do I need to write another question? – James Jenkins Jul 29 '14 at 14:35
• @JamesJenkins No, from what I can tell both his answers are perfectly correct. You don't need a full -1 g at the other end (counterweight) of the space elevator. All you need to do is make sure that both ends "weigh" the same and balance out to 0 at GEO, its center of mass. Since GEO to "top" is a lot longer in that case, and assuming constant mass per length, it "weighs" the same at larger mass. What you're likely forgetting is that a space elevator has to keep constant rotational period (synchronized with Earth's rotation) for all its parts regardless their orbital altitude. – TildalWave Jul 29 '14 at 14:54
• Maybe it wouldn't go amiss if David mentioned this constant angular speed requirement of the space elevator, and link it to orbital speed (in words). But I get 0.970698 g at 1.8 million kilometers. That's pretty close to 1 g. To match exactly 1 g at mean sea-level Earth (9.80665 m/s²), more precise distance from the center of the Earth would be 1,854,336 km. Of course, at such distance, the Moon might have something to say about your whole elevator system. You can use this centrifugal force calculator to make it somewhat easier. ;) – TildalWave Jul 29 '14 at 15:01
• BTW "up" is ambiguous on a space elevator. You're equally "up" when you're standing on the Earth than when you're at the end of its counterweight part. So in a sense, your question could be answered with "both". ;) – TildalWave Jul 29 '14 at 15:17
• @JamesJenkins What Tildawave said. Since the acceleration gradient is steeper earthside of geosynchronous, the earthside length is shorter. To balance the farside length needs to be longer. – HopDavid Jul 29 '14 at 15:33
Everywhere on the Space Elevator, "up" is the direction toward the geosynchronous point (GEO). Below GEO, gravity is exerting a stronger force on your body than the centrifugal force caused by rotation -- "down" is toward Earth; beyond GEO, the centrifugal force is stronger than gravity, so the net force on your body is away from the Earth. Right at GEO there's no "up" or "down," and indeed for some distance on either side of GEO the net force is too small for your senses to detect.
From the surface you climb up to GEO and then, without changing direction, you climb down to the counterweight at the outer end of the elevator.
The rule for "what holds the Space Elevator up" is that the sum of the net force on all the mass of the elevator above GEO must be larger than the sum of the net force on all the mass below GEO. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7925114035606384, "perplexity": 816.2012807511987}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178385534.85/warc/CC-MAIN-20210308235748-20210309025748-00349.warc.gz"} |
http://ezcodesample.com/DDRvsBagging.html | • Code samples
• Old archive
# DDR vs. Bagging
In this experiment we compared deep ensemble built by bagging and DDR. In original article deep ensemble is built by neural network and our DDR tests are built for Kolmogorov-Arnold model. Since the latter exposed in all test cases same or better accuracy, we use Kolmogorov-Arnold for both tests. We built 8 models by bagging and 8 models by DDR, then we generated 100 inputs, passed them to both ensembles and compared the accuracy.
The data is generated by Mike's formula
with error level $\delta = 0.8$, $[X_j, y]$ observed and $C_j$ random values uniformly distributed on $[0,1]$. Observed values were also randomly generated as uniformly distributed on $[0,1]$. The data set size was $10 000$ records. When single deterministic model is built for entire data set, its Pearson correlation coefficient for estimated and provided outputs is approximately $0.75$, which is kind of real life case.
In the accuracy test we generated 100 random inputs, passed them to models and obtained 3 samples per input:
• Array of 8 estimated outputs for bagging model
• Array of 8 estimated outputs for DDR model
• Array of 1024 possible Monte Carlo generated outputs
Monte Carlo sample is considered as TRUE ouput, to which other two are compared. The metric was Pearson correlation coefficient. It is applied for expectations and standard deviations. The other metric was Kolmogorov-Smirnov goodness-of-fit test, which shows if two samples are taken from the same population. The results are shown in the program print out below:
The accuracy for expectation is very high $0.99$ for both bagging and DDR, however, the standard deviation is not accurately estimated by bagging, it is $0.29$ when DDR gives $0.96$. Also Kolmogorov-Smirnov test passed for DDR in $84%$ cases, but for bagging only in $53%$ cases.
The general conclusion can be made, that bagging not returns accurate samples allowing make judgements about input dependent distributions and can be used only for estimation of expectations. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7329066395759583, "perplexity": 1632.1760823865854}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446710869.86/warc/CC-MAIN-20221201185801-20221201215801-00342.warc.gz"} |
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http://www.bbcbasic.co.uk/wiki/doku.php?id=re-dimensioning_20arrays&rev=1522502376&do=diff | # BBC BASIC Programmers' Reference
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re-dimensioning_20arrays
# Differences
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re-dimensioning_20arrays [2018/03/31 13:19]127.0.0.1 external edit re-dimensioning_20arrays [2019/04/09 22:08] (current)richardrussell Added BBCSDL procedures 2019/04/09 22:08 richardrussell Added BBCSDL procedures2018/04/17 18:21 tbest3112 Added syntax highlighting2018/03/31 13:19 external edit Go Next revision Previous revision 2019/04/09 22:08 richardrussell Added BBCSDL procedures2018/04/17 18:21 tbest3112 Added syntax highlighting2018/03/31 13:19 external edit Go Line 1: Line 1: =====Re-dimensioning arrays===== =====Re-dimensioning arrays===== - //by Richard Russell, May 2014//\\ \\ BBC BASIC does not have a **REDIM** or **REDIM PRESERVE** statement, as found in some other dialects of BASIC (REDIM allows you to increase the dimensions of an existing array - the contents are lost - and REDIM PRESERVE allows you to increase the dimensions of an array without destroying its contents). However it is not difficult to provide an equivalent functionality using user-defined procedures:\\ + //by Richard Russell, May 2014//\\ \\ BBC BASIC does not have a **REDIM** or **REDIM PRESERVE** statement, as found in some other dialects of BASIC (REDIM allows you to increase the dimensions of an existing array - the contents are lost - and REDIM PRESERVE allows you to increase the dimensions of an array without destroying its contents). However it is not difficult to provide an equivalent functionality using user-defined procedures (these are for BB4W, for BBCSDL see below):\\ + DEF PROCredim1d(RETURN P%,S%,D%) DEF PROCredim1d(RETURN P%,S%,D%) LOCAL A% LOCAL A% Line 49: Line 50: P% = A% P% = A% ENDPROC ENDPROC + The above procedures support 1-dimensional and 2-dimensional arrays; equivalent routines for arrays with more dimensions can be derived if required. If you REDIM PRESERVE a 2-dimensional (or more) array you should normally only change the **first** dimension; if you change another dimension the data will be 'preserved' but will appear to have **moved**. Note that it isn't usually sensible to **reduce** the size of an array.\\ \\ In each case the parameters to the procedure are the name of the array, the size of each element of the array (see table below) and the required dimension(s). As with the normal **DIM** statement, the available indices run from zero to the specified value.\\ \\ Here is a simple demonstration program:\\ The above procedures support 1-dimensional and 2-dimensional arrays; equivalent routines for arrays with more dimensions can be derived if required. If you REDIM PRESERVE a 2-dimensional (or more) array you should normally only change the **first** dimension; if you change another dimension the data will be 'preserved' but will appear to have **moved**. Note that it isn't usually sensible to **reduce** the size of an array.\\ \\ In each case the parameters to the procedure are the name of the array, the size of each element of the array (see table below) and the required dimension(s). As with the normal **DIM** statement, the available indices run from zero to the specified value.\\ \\ Here is a simple demonstration program:\\ + DIM array(100) DIM array(100) FOR I% = 0 TO 100 FOR I% = 0 TO 100 Line 63: Line 66: PRINT "Test completed successfully" PRINT "Test completed successfully" END END + Note that if you REDIM (not REDIM PRESERVE) a **string array** you must explicitly empty the array first:\\ Note that if you REDIM (not REDIM PRESERVE) a **string array** you must explicitly empty the array first:\\ + array\$() = "" array\$() = "" PROCredim1d(array\$(), ^array\$(1)-^array\$(0), newsize%) PROCredim1d(array\$(), ^array\$(1)-^array\$(0), newsize%) - \\ The most reliable way of determining the element size is to calculate it at run-time, as in the above examples, but for reference here are the appropriate sizes for each type of array:\\ \\ + + + Here are equivalent procedures for //BBC BASIC for SDL 2.0//: + + + DEF PROCredim1d(RETURN p%%,S%,D%) + LOCAL a%%,N% + IF ?p%%<>1 ERROR 14, "Bad use of array" + N% = 5+S%*(D%+1) + IF p%%<LOMEM OR p%%>HIMEM SYS "free", p%% + SYS "malloc", N% TO a%% + IF @platform% AND &40 ELSE a%%=!^a%% + IF a%%=0 ERROR 11, "DIM space" + SYS "memset", a%%, 0, N% + ?a%%=1 : a%%!1=D%+1 + p%% = a%% + ENDPROC + + DEF PROCredim2d(RETURN p%%,S%,D%,E%) + LOCAL a%%,N% + IF ?p%%<>2 ERROR 14, "Bad use of array" + N% = 9+S%*(D%+1)*(E%+1) + IF p%%<LOMEM OR p%%>HIMEM SYS "free", p%% + SYS "malloc", N% TO a%% + IF @platform% AND &40 ELSE a%%=!^a%% + IF a%%=0 ERROR 11, "DIM space" + SYS "memset", a%%, 0, N% + ?a%%=2 : a%%!1=D%+1 : a%%!5=E%+1 + p%% = a%% + ENDPROC + + DEF PROCredimpreserve1d(RETURN p%%,S%,D%) + LOCAL a%%,N%,O% + IF ?p%%<>1 ERROR 14, "Bad use of array" + N% = 5+S%*(D%+1) + O% = 5+S%*p%%!1 + SYS "malloc", N% TO a%% + IF @platform% AND &40 ELSE a%%=!^a%% + IF a%%=0 ERROR 11, "DIM space" + IF N%>O% SWAP N%,O% + SYS "memmove", a%%, p%%, N% + a%%!1=D%+1 + IF p%%<LOMEM OR p%%>HIMEM SYS "free", p%% + p%% = a%% + ENDPROC + + DEF PROCredimpreserve2d(RETURN p%%,S%,D%,E%) + LOCAL a%%,N%,O% + IF ?p%%<>2 ERROR 14, "Bad use of array" + N% = 9+S%*(D%+1)*(E%+1) + O% = 9+S%*p%%!1*p%%!5 + SYS "malloc", N% TO a%% + IF @platform% AND &40 ELSE a%%=!^a%% + IF a%%=0 ERROR 11, "DIM space" + IF N%>O% SWAP N%,O% + SYS "memmove", a%%, p%%, N% + a%%!1=D%+1 : a%%!5=E%+1 + IF p%%<LOMEM OR p%%>HIMEM SYS "free", p%% + p%% = a%% + ENDPROC + + + The most reliable way of determining the element size is to calculate it at run-time, as in the above examples, but for reference here are the appropriate sizes for each type of array:\\ | **byte** e.g. array&()\\ | size=**1**\\ | | **byte** e.g. array&()\\ | size=**1**\\ | Line 76: Line 143: | **64-bit integer** e.g. array%%() \\ | size=**8***\\ | | **64-bit integer** e.g. array%%() \\ | size=**8***\\ | | **80-bit float** e.g. array()\\ | size=**10***\\ | | **80-bit float** e.g. array()\\ | size=**10***\\ | - * BB4W version 6 only + * BB4W version 6 or BBCSDL | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8077308535575867, "perplexity": 14909.289032193034}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986677964.40/warc/CC-MAIN-20191018055014-20191018082514-00256.warc.gz"} |
http://uncyclopedia.wikia.com/wiki/Uncyclopedia:Village_Dump/archive5?oldid=5081532 | # Uncyclopedia:Village Dump/archive5
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## Favicon?
made that as a favicon. A simple parody of the Wikipedia W, if you want to use it cool, otherwise w/e just putting it out there --Sir Insertwackynamehere CUN VFP 21:28, 11 Sep 2005 (UTC)
We used to have a potato, but after the move it was taken off. Let's upload one? --Chronarion 00:35, 12 Sep 2005 (UTC)
## Sequel to World War I (video game)
Behold my creation, World War II (video game). Only two edits so far have not been done my me. Does this make me a nerd? Of course it does! Does it qualify for any awards? Hell no! Does anyone care? Guess not. Oh well, it was worth a shot. --Dac1990 01:54, 11 Sep 2005 (UTC)
Looks like we're accumulating enough of these for their own category - what with my Gulf War (video game) and Mooses' Invasion of Grenada (video game). Anyone want to undertake Vietnam War (video game), or Invasion of Afghanistan (video game)? -- Sir Codeine K·H·P·B·M·N·C·U·Bu. · (Harangue) 09:47, 11 Sep 2005 (UTC)
Good job. I added it to the World War template. I think that eventually, if we have enough well-done articles like this, we could start a category. "War Games" would be a good name. --Savethemooses 15:59, 11 Sep 2005 (UTC)
• I think "Invasion of Afghanistan" was just one part of 9/11 (video game). Though I probably should have checked here first. But that would have been considerate and thoughtful, and if I wanted to be considerate and thoughtful, I'd have stayed in my old playground :) --BobBobBob 19:42, 15 Sep 2005 (UTC)
## New Policy?
Many of the "Forum" articles are filled with vanity and such. So, do we create a policy against makeing articles about internet forums? They are inherently non-notable because of the anonymous nature of these sites --Nytrospawn 23:00, 10 Sep 2005 (UTC)
Kind of a grey area?... ZFGC has little potential beyond itself now, being about a Zelda forum (or some such) yet is not bad for what it is limited by. Irc users on the other hand has massive potential in its title to make fun of the various species of IRC users in general, yet is a piece of shit about a few friends (and vanity propagator, having links to top level namespace for its members, arg (RC did warn the two main creators, no reaction so far (and they are on Ban Patrol))). But something like Steam Forums is in between: mostly crap without much chance for improvement. There seems to be an edit war going on in there now over the section 'list of spamm0rs'. So in summary: I have no opinion. --Splaka 23:15, 10 Sep 2005 (UTC)
I vote we (meaing someone with 1331 5|>i115) write the definitive Internet forum article, and redirect all other internet forums to that page. 23:40, 10 Sep 2005 (UTC)
I'm no fan of those kind of articles. They've got a limited audience, often descend into in-joke hell and tend not be particularly funny. And besides, they've got a whole forum for that kind of business. It's not like we turn up there and start raving about the virtues of Uncyclopedia, is it? -- Sir Codeine K·H·P·B·M·N·C·U·Bu. · (Harangue) 23:51, 10 Sep 2005 (UTC)
Denied. Uncyclopedia is not Wikipedia. I personally would prefer to keep forum style articles if they're funny to SOMEBODY. ONLY if they are funny to nobody, should they be deleted. Absolutely no special targeted policy can be instated, that goes against wikibelief. If it totally sucks, vfd. There's no point in writing a special rule or anything. Use standard policy.--Chronarion 17:27, 11 Sep 2005 (UTC)
Its true some of those articles are have redeemable qualities. But what I want to have as part of policy is to have people understand that "Forum" articles are not the best vehicle for satire. If someone can make a really good article about a forum, without it delving into inside jokes and "spamz0rz", then thats fine. But I've seen many more that arent funny --Nytrospawn 00:24, 11 Sep 2005 (UTC)
Or should I say more specifically, most of the articles do use inside jokes and lists of people I dont give a ratfuck about --Nytrospawn 00:26, 11 Sep 2005 (UTC)
Pardon my being incredibly vain and self-promoting, but I already wrote a "definitive internet forum article" at Forum. I believe Famine called it a "sterling piece of work." Of course, how far can you trust a man named after one of the terrible scourges of humanity...? --Jordanus 05:56, 11 Sep 2005 (UTC)
Well, shit. I forgot all about that. No wonder I was sure someone could come up with a good forum article. I already read it, and moved it to its own page. And apparently called it a "sterling piece of work." Some admin should go back and fix all my stuipd-ass comments about needing an internet forum article. I now vote to:
A: move Forum to Internet forum just in case someone ever needs to write a non-internet forum article.
B: redirect all forum articles to the appropriate section of that article.
15:16, 11 Sep 2005 (UTC)
Heh. I didn't notice that you were the one who made that comment, Sir Famine (I'll have to get used to the title). I can't believe that you didn't remember the incredible saga of the rebellious anti-uncyclopedia-moving-the-chat-page anarchists. Anyway, your idea's fine by me. My article had a small section about the history of forums, but it was mostly a lead-up to a discussion about modern ones. I guess I could use that materiel to write an article about historic forums if you guys wanted; it'd be a stretch, though. If someone else wants to write a new non-Internet forum article that's OK too. I don't really care either way--Jordanus 16:59, 11 Sep 2005 (UTC)
I'm in concordance with chron. Due to our established psychic link, I've come to back up his statement. Basically, we have things in place to completely nuke the things that make LALALALALA FORUMZ LOLOL articles suck. The "Inside joke" rule and content rules of HTBFANJS cover this, and unless they're something everyone can appreciate (which, in most situations never happens) there's not point in making a "magic bullet" rule--Sir Flammable KUN 17:34, 11 Sep 2005 (UTC)
I agree with Flammable and Chronarian. If we start making blanket-delete policies just because 90% of some-subject-related articles suck, there really won't be much left. It's that 10% minority in every subject that makes Uncyclopedia what it is, and we don't want to inadvertently throw away any babies. --Spintherism 17:55, 11 Sep 2005 (UTC)
I always remove from these types of articles any section that's just a list of usernames, sometimes followed by descriptions such as "He really likes penguins and cheese." or "Nazi administrator who bans everyone." Example of what I'm talking about. While I agree that we shouldn't delete articles just for being non-notable (how notable is something that's made up or non-existant?) these userlists are among the weakest vanity I've ever seen. Uncyclopedia is not a guestbook, hence I just throw away that shit on the spot. --EvilZak 22:42, 11 Sep 2005 (UTC)
Personally I think some of these userlists are okay, but move them to vanity subpages. I thought it was slightly funny even without visiting the forum as a regular. Anyway, use your judgement. For this forum list, I think that making it a subpage (using the / thing so it won't be randomed) is perfectly acceptable. It makes them happy, no? I'm an inclusionist. Everybody should be represented as long as they don't hurt others. --Chronarion 00:38, 12 Sep 2005 (UTC)
Every now and then, even a vanity list of names and in-jokes can open up to unintentional hilarity. The mixing of tenses and "we did this and they did that and we did this LOL" gives it a sort of James Joyce feel. --Monthenor 02:51, 12 Sep 2005 (UTC)
## Nude (gasp!) photographs
OK, someone posted a nude photo (tasteful, but nude) of Cindy Crawford in the article of the same name. I reverted it once to take it out -- assuming that (1) people surfing Uncyclopedia at work probably wouldn't appreciate titty pics popping up on their screen and (2) copyright issues blah blah blah. But then someone reverted again to put it back in. I can't find any policy on Uncyclopedia regarding this. Thoughts? --Bouahat 06:56, 9 Sep 2005 (UTC)
Hmm, since uncyclopedia is on the same network of servers as Wikipedia (like wikimedia, wikicities, etc), I would guess the policy is similar to (or at least as lenient as) theirs. I am guessing it should be funny, or at least be utilized in a funny manner (orphaned and unused images are periodically deleted). But I am a n00b, my 2 centage. --Splaka 07:11, 9 Sep 2005 (UTC)
Suggestion:Remove the picture, then put one of those invisible <!--things on the page stating not to put it back. I don't know why I posted it here instead of doing it myself. --Cheeseboi 20:58, 9 Sep 2005 (UTC)
The big problem that I see is that it just doesn't seem funny to me and I can't even see what the point was beyond posting a nude pic. If there was some way it could be made funnier (I dunno, maybe something with the Janet Jackson boob slip thing) then it would be fine to keep under the Wikipedia policy that Sir Splaka brings up, but otherwise it seems like it ought to go. -- ERTW MUN 23:40, 9 Sep 2005 (UTC)
Explicit/nude pictures tend to be unfunny anyway, as most of them have been taken from non-funny sources like Playboy and whatever and don't really tend to contribute much. Unless photoshopped or originally intended to be humorous, nude pics really don't add much to Uncyclopedia. And unfortunately, non-original funny nude pictures tend to be the most popular pictures on the Intarweb, and as such are really not worthy of inclusion on Uncyc (unless we're trying to parody them). --stillwaters/Talk 23:54, 9 Sep 2005 (UTC)
What about stuff like the picture at Hentaium? It fits with the article, but, well, it's pretty explicit... --Rcmurphy KUN 00:04, 10 Sep 2005 (UTC)
We could slap some sort of NSFW tag on Hentaium, but I'd say it's their fault for browsing to a page named Hentaium in the first place. Shock! Naked people on Hentaium?! I am teh surpized! Basically, I feel that if we don't have any problem putting fuck in bold italics, why fret over images that pertain to the article? --Monthenor 02:18, 10 Sep 2005 (UTC)
I placed the picture on the Hentaium article. It is a public domain image that is available on Wikipedia. Did the standards of Uncyclopedia rise above Wikipedia recently? --KP CUN 03:25, 10 Sep 2005 (UTC)
I personally would be shocked and horrified if Uncyclopedia became some cesspoolish repository of nude images. Especially since it is quite likely that they would be uncategorized and unrated, and thus contribute nothing to Uncyclopedia. If that ever happens, I pledge to spend my time browsing all such images, judging, categorizing, and making sure they are fit for Uncyclopedia. Any which aren't will be confiscated.
But seriously, I for one won't abide by any prudish policy which would make us more Puritan than Wikipedia. A little titty isn't a bad thing here. We have far, far more offensive shit on this site. As Jon Stewart said about America, The Book, (roughly paraphrased) "They banned it in Mississippi because it had nude pictures of old people in it. Not because we used the phrase "teabagging a hooker" in it." Really, tasteful nude images are by far the least shocking and offensive stuff on this site. While the image in question isn't really funny, I don't see the fact that it's nudity as a reason to dump it. If/when we get a funnier picture, great, let's use it. For now, I'll put that on my favorites list to head to when I need a pick-me up. ;) 22:09, 10 Sep 2005 (UTC)
My intention wasn't to be prudish or offended, but just wondering aloud whether it's a good idea to have gratuitous nude photos on Uncyclopedia. I like to surf the site at work when I have the occasional break when I'm not doing something else. And it would be not a good thing to have passers-by seeing naked pics on my computer. But I've read the comments here -- and have concluded that it would be far easier for me to just not surf this site at work (or surf the site very carefully) rather than to try to impose my conditions on the whole site. --Bouahat 22:29, 11 Sep 2005 (UTC)
If an occasional page with boobies on it would bad for you to stumble across at work, I'd highly recommend not browsing sites which allow anon edits and don't have any "regularly scheduled" moderators. There's nothing to really stop someone dropping a dripping snatch into the "did you know" or "in the news" templates and having that splashed across the main page. Or doing that to just about any other page here.
Personally, even though I'm an admin here, I'd never browse this site at work. According to our usage policy, there's a fair amount here that could potentially get me fired. Even if I stay away from those parts of the site, this place can change literally by the minute, and you never know what you're going to stumble across. We admins are here when we can be, but there's no set schedule, and we don't have "rounds" or any real method to how we keep this place looking good. We just put out fires where we see them. If you browse this site at work, beware. 22:49, 11 Sep 2005 (UTC)
heh if Wikipedia can do it I think we can (NSFW) --Sir Insertwackynamehere CUN VFP 19:13, 11 Sep 2005 (UTC)
SOLUTION? here I made these to be placed at tops of articles/image descriptions: Template:NSFWArticle and Template:NSFWImage --Sir Insertwackynamehere CUN VFP 02:38, 12 Sep 2005 (UTC)
I have made it so 500px of margin space are below it. it doesnt work well for images unfortuantly where the description is already below the image :P --Sir Insertwackynamehere CUN VFP 02:53, 12 Sep 2005 (UTC)
Sweet. I'm going to place that at the bottom of every page which has any chance of ever becoming NSFW. Which I hope someone does a good job on. -- 01:15, 13 Sep 2005 (UTC)
Heh its best at the top because it has a 500px margin at the bottom in order to sort of cut off the stuff (doesnt work on my screen 1280x1024 :P) but I dont want to drive 800x600 users insane :P also I love that idea of having your sig in a template--Sir Insertwackynamehere CUN VFP 21:58, 13 Sep 2005 (UTC)
Damn, I hate always being too clever. My point was that I plan on subverting a working notice to make it useless. On purpose. It's the Discordian in me. Mom's side. -- 22:35, 13 Sep 2005 (UTC)
Oh haha sorry kinda tired. I like that idea :) I'll edit the margin thingy --Insertwackynamehere 00:12, 14 Sep 2005 (UTC)
In the interest of being more provocative I have doubled up the image. -- ERTW MUN 00:29, 16 Sep 2005 (UTC)
### Suggestion
What if we simply tag images with nudity with words such as (nudity) in their filenames? Then any sensible Firefox users can simply adblock such images. It's pretty trivial to install Firefox nowadays, and if your workplace favours another browser (e.g. you work for Microsoft), you can grab an alternative skin to fool your boss/supervisor. --stillwaters/Talk 01:33, 13 Sep 2005 (UTC)
And for the rest of us home users, it will make searching for those images all the easier. I'm for that idea. -- 22:35, 13 Sep 2005 (UTC)
Stillwaters -- that is probably the best idea yet!
1. Tag images with words such as (nudity) in their filenames
2. Limit access to Uncyclopedia PLUS! members
3. Gouge Charge a reasonable fee to view nude photos
4. ???
5. Profit!
--Bouahat 21:21, 14 Sep 2005 (UTC)
So who’s volunteering to look at all the images to find nudity? --KP CUN 21:49, 14 Sep 2005 (UTC)
1...2...3
NOT IT!!! -- 22:41, 14 Sep 2005 (UTC)
Insertwackynamehere is off labeling them now with his NSFWImage template. When he is done you should be able to find a complete list at Special:Whatlinkshere/Template:NSFWImage (or Category:Not safe for work). Can images be moved (renamed) by Administrators? Or does the action require database manipulation? Would redirects be put in place? Also, I think a better file scheme would be (for example) Image:Jenna.jpg --> Image:(NSFW)-Jenna.jpg. --Splaka 23:58, 14 Sep 2005 (UTC)
heh yup, but I'm probably gonna miss a bunch. I was just looking around vaguely based on a few articles that sort of interlink, but the best idea is, you see an image, tag it. also we could run searches for famous actresses/pornstars/etc I'm pretty much out for tonite i think though, and I have school tommorow :( --Insertwackynamehere 00:34, 15 Sep 2005 (UTC)
### New Image!
I think this fits nicely, all the aquaball stuff gets kinda old :P --Insertwackynamehere 01:42, 17 Sep 2005 (UTC)
## Would a 'pedia about Boston be called...
WickedPedia? --Savethemooses 00:52, 8 Sep 2005 (UTC)
Nah, man! Wha's wrong with you! It's like hella lame and shit, dude. It would be hella better to like totally do something else, like a. uh, like a like, I don't know, whatever, you know?
What the fuck is hella? You kids and your slang, Im gonna kills you.--Nytrospawn 16:59, 9 Sep 2005 (UTC)
Hella is a particularly annoying slang from Northern Californa. Chances are you can spot a long-time Northern Californian by their use of it. (Yes, I am a native NCian (yes, I use hella without thinking about it (yes, it sucks))). --Splaka 19:56, 9 Sep 2005 (UTC)
## Vandals! Zounds!
SOMEbody vandalized my masterpiece Open-Heart Surgery for Dummies. Who possibly could have done such a thing? --Savethemooses 17:31, 5 Sep 2005 (UTC)
Someone named Gerald Carter, apparently. HTH. --Marcos_Malo OUN S7fc BOotS Bur. | Talk 19:23, 5 Sep 2005 (UTC)
Hmm, the VFD page looks all screwed up, the last 6 hours that is. Ballot stuffing and sections deleted? Or were Gazmo and Riemann_hypothesis reprieved without any archival of the votes? --Splaka 20:33, 5 Sep 2005 (UTC)
## Reminder to add to Template:Recent
I added the note about about the beginners guide to the bottom of the edit window, I was just wondering if it's worth adding a reminder once an article is complete to add it to Template:Recent so we can all laugh at the author article, if so suggested wording? --The Right Honourable Maj Sir Elvis UmP KUN FIC MDA VFH Bur. CM and bars UGM F@H (Petition) 11:22, 5 Sep 2005 (UTC)
I approve of this idea, as I always forget to put my new articles on there. As for wording: "When you think your article is complete, remember to add it to Template:Recent so the vandals know they have a new target." --Monthenor 20:44, 5 Sep 2005 (UTC)
See? Without Godboost's presence in the template, I doubt our esteemed vandal population would have even known it was there, and then they could not have blessed the world with their great wisdom. --Monthenor 17:51, 6 Sep 2005 (UTC)
There's a recent template? Damn, now I'm REALLY in line for the n00b of the month award. I guess I sorta-knew that long ago, but damn, I forgot all about it. 01:04, 6 Sep 2005 (UTC)
## Steve Ballmer's Hitlist
Well in honour of Steve Ballmer's recently publicised bout of insanity I have put together the following template: {{ballmer|the Village Dump}} Is it wrong that when I read that article the first thing that popped into my mind was that the quote would work well alongside the Oscar Wildeisms at Uncyclopedia? -- ERTW MUN 22:25, 3 Sep 2005 (UTC)
How would one go about killing a search engine? Pull the plug on its Boolean operators? --Savethemooses 01:57, 4 Sep 2005 (UTC)
I don't know, but Ballmer says he's burried search engines before. -- ERTW MUN 03:28, 4 Sep 2005 (UTC)
The way that guy looks, Id be hideing under the floor boards if I was Google. Thats if Google was a person and not an intangible electronic medium--Nytrospawn 13:54, 4 Sep 2005 (UTC)
You know, we've traditionally had a vast deleteable amount of "xxx should die" or "xxx on yyy's shitlist" articles. I think we finally have one that's worthwhile. Balmer meshed with Oprah as her hitman, with their list of past and future victims could make for a decent article. I'll sit here and think about that, while someone else does it. 16:11, 4 Sep 2005 (UTC)
But xxx should die. Seriously. xxx needs to fucking DIE. Same for yyy. --Savethemooses 01:22, 5 Sep 2005 (UTC)
xxx is now on the hitlist, unfortunately there is no yyy article to put on the list. -- ERTW MUN 04:38, 5 Sep 2005 (UTC)
If yyy should die, but it's already dead, then it's a zombie. You have to shoot it in the head. IN THE EFFING HEAD! You dumbasses never get it right. That's why the zombies always eat your brains. --BobBobBob 19:50, 15 Sep 2005 (UTC)
## Templatyness
I don't know who requested this, or if anyone requested this, but here's a template for slanderous pages. No offense, Elvis. Template:Slander --Cheeseboi 19:50, 2 Sep 2005 (UTC)
Sorry to put my language Nazi hat on, but when it's written down it's libel not slander. --User:IMBJR/sig 20:07, 2 Sep 2005 (UTC)
Darn it, IMBJR is teh right.
Stolen Quote: Recently the difference between slander and libel has become less distinct since speaking on public television or radio amounts to libel because of the public dissemination of the spoken words. For this reason defamation through television or radio is considered libel in countries like Canada, and may be handled as libel in the United States where laws differ from state to state. Posting false and defamatory information online also amounts to libel, not just on a website but also in the context of a discussion in a USENET newsgroup, listserv or IRC chat room. Several libel lawsuits in various countries have been brought against parties for Internet libel, somtimes referred to as cyberlibel.
So much for slandanity. But libeldanity just doesn't have the same ring. Hmm, one could also hardly call things like "fcuk u hmo" as written, since it is more accurately dictated by lobotomized monkeys. Using defamation is probably best... (Defevanity has a nice ring, like defecated defaming vanity) --Splaka Bur. SG CM © 20:25, 2 Sep 2005 (UTC)
EDIT CONFLICT (oh well I'm postong this anyway even if it now makes no sense) It wasn't so much slander but slandanity I was looking for, Something like "Just because you think your mates a Dick, we don't give a shit, both of you are insignifcant little turds that are not fit to shine my shoes - Sir Elvis", but funny :-/ I'm sure we can find a use for {{slander}} however :-)!--Sir Elvis KUN FIC Bur. | Petition 20:30, 2 Sep 2005 (UTC)
Sorry, I seem to have a skill for that, especially with Flammable. I am pondering adopting a title like Anti-Admin Edit Conflict Bastard. Or maybe I should just automatically be banned for 30 seconds whenever an admin hits 'edit'. --Splaka Bur. SG CM © 20:55, 2 Sep 2005 (UTC)
I could move it to Template:Libel if you want, IMBJR. (BTW, Sir Elvis, I didn't know slandanity was a play on words. I have a somewhat limited ability to distinguish puns and normal stuff.)--Cheeseboi 21:01, 2 Sep 2005 (UTC)
Current VFD usage of these appears to be $slandanity = slander + vanity$and $V.A.I.N. = vanity + attack + inside joke + nonnotable$--Carlb 21:56, 2 Sep 2005 (UTC)
I sort of didn't read everything above, but slander can mean negative and false statements in general (written or spoken), it's only when legally speaking that it's used with along with the word libel to differentiate between written and spoken aspersions. (I just verified with dictionary.com and noticed that they have a wikipedia-based thesaurus function. Interesting.) --Spintherism 22:33, 2 Sep 2005 (UTC)
At elvis's request... Template:Slandanity --Cheeseboi 17:15, 3 Sep 2005 (UTC)
I played with it slightly hope thats OK?--Sir Elvis KUN FIC Bur. | Petition 20:29, 3 Sep 2005 (UTC)
That's A-OK, Elvis. Long as I have your approval.--Cheeseboi 22:55, 3 Sep 2005 (UTC)
## Links to foreign Language Uncyclopedias
Now we have http://desencyclopedie.wikicities.com/wiki/Accueil (Sorta the French Uncyclopedia) and http://uncyclopedia.de/wiki/index.php/Hauptseite (The German Uncyclopedia) can we come to a consensus about linking/sister project boxing them (given the ED mess I thought I should check first) we already have some that are tagged with a link to desencyclopedie (because they are translations of original articles from there, which is fair enough) but what about translations of our articles (and spooky ones that have no connection whatsoever but have the same name/topic) on these two?--Sir Elvis KUN FIC Bur. | Petition 19:18, 2 Sep 2005 (UTC)
Cet article, basé sur le texte Uncyclopédien Uncyclopedia:Village Dump, est disponible uniquement sous licence CC-BY-NC-SA de Creative Commons.
Dunno about .de (as that site still looks rather empty) but the situation on dÉsencyclpédie regarding translations of Uncyclopédia is an exact mirror image of the {{dÉ}} tag on translations of their stuff here - dÉsencyclpédie is a sister project (as part of Wikicities) and is filled with templates with li'l potato icons and links back to the original English-language articles and images here. See for a list of Uncyclopedia articles which have French-language translations. Use {{dÉ|nom d'article...}} or {{Uncyclopédia|article name}} to link there or link back here, respectively. The question of unrelated article/same topic hasn't been looked at, and so far the original article (in whichever language) doesn't link back to any translations of that article (the links point to the original), but I can't see it becoming a major issue. --Carlb 21:44, 2 Sep 2005 (UTC)
## Mediocre User for Fake Adminship
I am retiring from Uncyclopedia now, after a short career marked by mediocre contentent. In exchange for my half-hearted services I would like a superfluous, meaningless title, like, "Junior Fake Administrator in Charge of Doing Nothing." I feal that I deserve nothing less from you, who ate away so much of my time that I could have been spending productively if I hadn't been wasting it here. And I certainly deserve nothing better from you, due to my horrible, horrible editing.
Ciao.
--Cowation 04:25, 2 Sep 2005 (UTC)
As long as I can be a Senior Fake Administrator in Charge of Doing Nothing, just to get the point across that my penis is larger than yours, you have my full support. --Spintherism 05:14, 2 Sep 2005 (UTC)
Fake administrator? Administrating isn't fake! It's just staged. Sure, the storylines and such are predetermined by writers and all bans and deletions are choreographed. However, all the "fake" 3-second-long bans are real bans, and if botched someone may wind up banned for 3 years. If you don't have the training, then please, don't try to administrate in your backyard. (I support Cowation being a fake administrator as long as "The Cowating One" puts me over at AdministrateMania 22.) --EvilZak 21:12, 2 Sep 2005 (UTC)
Hah! I happen to know that EvilZak is, on a regular basis, lip-syncing when he is deleting QVFDed articles. --Marcos_Malo OUN S7fc BOotS Bur. | Talk 23:32, 3 Sep 2005 (UTC)
I believe we could kill two birds with one stone here by just dropping the template:Inactive Sysop on his page. ;) Not that Cowation isn't deserving of the title Junior Unadmin in Training. --Famine 00:47, 3 Sep 2005 (UTC)
## User:Brephophagia
Take a look at this guy's edits: Brephophagia (TalkContribs (del)EditcountBlock (rem-lst-all)LogsGroups). Do we consider this sort of thing vandalism? I can sort of see where he thinks it's funny to claim that every city in the world is in Texas, but I dunno... it seems kind of obsessive to me. I left him a message on his Talk page asking him where he was going with this and he stopped. Opinions? -- Codeine 22:53, 1 Sep 2005 (UTC)
It seems pretty funny to me, and even if I'm in the minority on the funny, I don't think that sort of thing should be considered negative vandalism or penalized. --Spintherism 23:19, 1 Sep 2005 (UTC)
Doesnt seem so bad. Just make sure he doesnt go destroying stuff or whatever --Nytrospawn 01:51, 2 Sep 2005 (UTC)
## Uncyclopedia in New York Times
Blessings from His Noodly Appendage, Uncyclopedia was referred to in the same sentence as Wikipedia, not to mention before Wikipedia, as an online encyclopedia. --stillwaters/Talk 18:05, 1 Sep 2005 (UTC)
Woohoo! The takeover has begun! Venganza.org also linked to us again a couple days ago after I emailed Prophet Bobby about the FSM being our featured article. --Rcmurphy KUN 18:23, 1 Sep 2005 (UTC)
Haha! Brilliant! My monkey armies are poised to strike! --PantsMacKenzie 21:54, 1 Sep 2005 (UTC)
I have a feeling that Uncyclopedia being listed as on equal online encyclopedia grounds with Wikipedia will be rather frustrating to those folks.--Spintherism 01:17, 2 Sep 2005 (UTC)
Well, serves them right, for making such a blatant parody of Uncyclopedia. :( --Splaka Bur. SG CM © 01:33, 2 Sep 2005 (UTC)
And frankly, what does wikipedia really have to offer? Facts? Ppppth. I can make up better facts than they have on any of their pages. You could write wikipedia just by watching the news all day, and writing stuff down. I choose the road less traveled, past the raven, and through the haunted forest. Uncyclopedia beats wikipedia pants down. Soon all news media will forget about wikipedia, and Uncyclopedia will rule the web supreme. </crazy prophet> What? Where am I? Who said that? --Famine 02:02, 2 Sep 2005 (UTC)
I love you, Famine --PantsMacKenzie 01:49, 4 Sep 2005 (UTC)
Another one bites the dust. FSM forever! --Nytrospawn 02:28, 2 Sep 2005 (UTC)
## New Orleans is sinking, man
Can we add a donation link to the Red Cross or something on the front page for the victims of Katrina? I know it's not Uncyclopedic, but it's really, really bad from at least Ocean Springs, MS to New Orleans (and it looks like it's getting even worse in the latter). I'm away at school now, but my home is (or maybe was, I don't know yet) in one of the hardest-hit places, and I have a lot of family and friends from New Orleans and other places on the coast. Some of them stayed to weather the storm and I haven't heard from them yet. I feel really useless being out of town for all this and I'd like to feel like I'm doing something. Who knows if anyone would donate, but there's certainly a chance. --Rcmurphy KUN 03:04, 31 Aug 2005 (UTC)
Why not just edit the existing Template:Donate to put your disaster-related message there? Nothing there now but silliness... --Carlb 08:27, 31 Aug 2005 (UTC)
We can do it like Wikipedia. They spam headline messages everywhere for important news. And I of course support adding a link to a reputable group that is doing stuff to aid New Orleans (and other places). Slashdot says they might need 9 weeks to pump out all that water, and we all know Slashdot is always right. Too bad we don't have a village pump to spare, but we can link, perhaps also on the side bar. --stillwaters/Talk 10:08, 31 Aug 2005 (UTC)
There will soon be hundreds of charities seeking donations for New Orleans. I think if we start taking donations or a link to a charity, we'll only be adding to the noise factor. On that basis, I am mildly opposed. On the other hand, if it could be done in a funny way, go for it. --Marcos_Malo OUN S7fc BOotS Bur. | Talk 11:09, 31 Aug 2005 (UTC)
How about just an image link to a Red Cross donation site? And some little guilt message. Basically a charity ad banner, but uncyclopledia style. Mr T saying: "Help fund construction of New New Orleans, Foo! Donate to the Red Cross" or such (what does the red cross have to do with construction...well you know what I mean). --Splaka Bur. SG CM © 11:23, 31 Aug 2005 (UTC)
Is there not a Disasters Emergency Committee (http://www.dec.org.uk/) link organisation in the US, of course not wishing to sound unkind but there are larger disasters going on and have gone on that we havn't done anything about, perhaps we should include links to them? (new version of Template:Donate comming up)--Sir Elvis KUN FIC Bur. | Petition 13:11, 31 Aug 2005 (UTC)\
If you find {{{1}}} or its sista projects amusing, please consider making a donation to help the victims of the War on Terra:
1. Red Cross relief for Hurricane Katrina, to build a New New Orleans
2. DEC Niger Crisis Appeal (recommended for Mediocre Britain taxpayers)
3. ICRC, various including Sudan and Iraq
What do people think, any more to add?--Sir Elvis KUN FIC Bur. | Petition 13:22, 31 Aug 2005 (UTC)
Or maybe relate it to the War on Terra, with a message from President Cruise to stay the course, show our determination to beat the Terra-ists, and promising to support the growth of democracy in Louisiana?
I suppose this then raises the question of whether we want to link to the related Uncyclopedia articles for these places, like:
</td>
If you find Uncyclopedia or its sista projects amusing, please consider making a donation to help the victims of the War on Terra: Red Cross relief for Hurricane Katrina, to build a New New Orleans Disasters Emergency Committee Niger, various (recommended for Mediocre Britain taxpayers) ICRC, various including Sudan and Iraq
--Carlb 16:21, 31 Aug 2005 (UTC)
If anyone has just cause why the template should not be changed then speak now or forever STFU else by the Power vested in me by whoever it was stupid enough to make me an admin I herby change it.--Sir Elvis KUN FIC Bur. | Petition 16:28, 31 Aug 2005 (UTC)
I like the template, and the mix of humor and seriousness, but it's not very visible there. How about this: we add a permanent Donations link to the sidebar (perhaps replacing the "Report a problem" link, since I think that was just supposed to be for the move to Wikia), move the Donate template off the main page and then add a small bar, maybe something like this:
"Hey cheapskate. How about making a donation to help [whatever cause]?" ~~ Oscar Wilde
across the top of the front page when a disaster like Katrina or the Asian tsunami happens. That way the template can keep the links to charities that serve other causes, like Elvis mentioned, but we can also alert people to "new" events (I'm thinking specifically of natural disasters since they often require lots of money within a relatively short amount of time).
I know I'm being reactionary here because the hurricane has affected me personally, and of course if other people think the donation thing is insensitive or inappropriate for the site we don't have to do it. --Rcmurphy KUN 23:43, 31 Aug 2005 (UTC)
Report a problem is starting to get some use so I'm not sure about replacing it, how hard would it be to add a donate link to the menu? --Sir Elvis KUN FIC Bur. | Petition 00:19, 1 Sep 2005 (UTC)
What about a wikipedia like permant link to each page but utilising User:Algorithms random plugin to change between variouse causes, although I am slightly worried about getting into a bun fight over "worthy" causes, can we get a view from cron? --Sir Elvis KUN FIC Bur. | Petition 00:22, 1 Sep 2005 (UTC)
My take on this is that i'd be willing to put a link on the main page somewhere, but I do not want a general donations thing. I don't want to make sidebar changes, but somewhere on the main page wouldn't bother me much at all. --Chronarion 12:55, 1 Sep 2005 (UTC)
Why not leave it as-is but just change the background colour slightly so that it isn't lost in a sea of coloured boxes? If this is intended to be a response to specific disasters, it doesn't need to be a permanent link, just a mainpage notice that shows up in times of major disaster. --Carlb 01:52, 1 Sep 2005 (UTC)
## Image Problem
I have an image problem. Not what your thinking. I've uploaded quite a few images b4 without problem, but this one http://uncyclopedia.wikia.com/wiki/Image:Newspiderman.jpg won't show. When you click on the history for the image you can see it though? Whats happening? Why does my head hurt? Please help....... Mhaille
The image works for me. Maybe you forgot to make the necessary one-pound flesh sacrifice to Kompútar, he god of all things computational. It’s also good to make a ritual sacrifice to Etherné, the goddess of networks and the internet. --KP CUN 23:30, 30 Aug 2005 (UTC)
And you might have forgotten to pay me your upload tarrif. It happens sometimes. Paypal me \$35 (78 GBP) and it should work just fine. --Famine 23:38, 30 Aug 2005 (UTC)
Ah ha!!!!! I've gotten it to work. Looks like my Ad Blocking on Norton Firewall doesn't like something in the name of the file.......spider? Just shows the old adage "poke around long enough and it'll work" is true... Mhaille
That is bizzare. The adblock plugin for Firefox works wonders for me, and I have yet to have an issue like that. If it makes any difference to you. And BTW, if you look to your left, at the bottom of the navigation bar you will see a link called "Report a problem". Yeah. --Famine 23:55, 30 Aug 2005 (UTC)
THATS what thats for? Duh! :) Mhaille
## Drama-rama
User:2004-12-29T22:45Z has blanked portions of Sherrod DeGrippo, Encyclopædia Dramatica, Frienditto to "avoid drama" and to "correct facts". I rolled the changes back and blocked him for 24 hours. I'd have blocked him more, but I wanted to check here first. --Marcos_Malo OUN S7fc BOotS Bur. | Talk 16:39, 30 Aug 2005 (UTC)
This is information that he included himself, given it's factual nature and that he included it I've unblocked him and reverted to his version, this is only an emergency response if other decide to re-block/revert do so --Sir Elvis KUN FIC Bur. | Petition 16:51, 30 Aug 2005 (UTC)
Perhaps he has received a legal threat for libel? That would fit with SD's M.O. I'm asking 2004 what is up, so perhaps we'll learn what is going on. --Marcos_Malo OUN S7fc BOotS Bur. | Talk 17:12, 30 Aug 2005 (UTC)
Sorry for the rather rushed response then disapearing, my net connection was playing up and I only had time to unblock an revert before I had to go and this is the first time I've been able to get back online. As I've said I was under the impression that he was just removing contnent that he had added and I given the shennigans over there I didn't think it was fair for him to get banned (obviously MM couldn't have known this, as he hasn't been involved over there, so this isn't in anyway a comment on him in his shoes I would probably have done the same). Also if others want to add it back in on their own initiative thats fine by me (although I was never particularly comfortable with the borderline vindictiveness of it) --Sir Elvis KUN FIC Bur. | Petition 22:06, 30 Aug 2005 (UTC)
Ten four, good buddy. I really don't have an interest in ED at and all that, but I can't stand being pushed around (and by extension, Uncyclopedia), especially by someone or something like SD. My hackles are smoothed back now, so I'm happy to go along with whatever the group decides. --Marcos_Malo OUN S7fc BOotS Bur. | Talk 23:38, 30 Aug 2005 (UTC)
Apparently both wikipedia:Wikipedia:Administrators'_noticeboard/3RR#User:2004-12-29T22:45Z and wikipedia:Wikipedia:Administrators'_noticeboard/3RR#User:SchmuckyTheCat got the boot from WP for 24hrs for reverting too quickly (more than the 3RR per day limit), and the wikipedia:Encyclopædia Dramatica page locked, so perhaps he's gone into damage-control mode at the moment? Still, it is odd to see factual info blanked by the very person who added it in the first place. ??? --Carlb 16:58, 30 Aug 2005 (UTC)
Yeah it is strange. Id have to agree with others that the deletions that the user made be might due to external pressure. --Nytrospawn 17:34, 30 Aug 2005 (UTC)
## Jeff Gannon
Can someone tell me why this page totally disappeared?
Maybe it sucked? --Nytrospawn 14:53, 27 Aug 2005 (UTC)
Possibly, but there was never a vfd on it, so I doubt it.
See Uncyclopedia:Pages_for_deletion/archive10#Jeff_Gannon for the very brief vfd. --Splaka Bur. SG CM © 04:51, 30 Aug 2005 (UTC)
You doubted that it sucked? Or that it disappeared because it sucked? Perhaps you also want to check out this page. --Marcos_Malo OUN S7fc BOotS Bur. | Talk 05:36, 30 Aug 2005 (UTC)
I can personally tell you why it disappeared, because I disappered it. It wasn't funny. It reads like a carthartic release of a great deal of pent-up hostility towards republicans and some deep-seated latent homosexual desires. To be frank, right-wing dick sucking has been overdone. Had you (or the author, but I assume it's you due to your concern) continued on the slow-pitch softball path, (and it was funny) I'd have spared it. Least you think I'm just a conservative dicksucker myself, I support all political parties - in the "support them being dragged out into a field en-masse and shot" sort of way. Short term limits for all electable positions are the only thing which can save this country.
Regardless, as I posted elsewhere on this site, I don't add a lot of content anymore, because I often don't have the muse to produce an article of sufficient quality. A large number of my inital edits to this site were whacked, and now I realize that it takes a great deal of time to produce something really worthwhile. To be honest, the phrase "gang banged him into submission" lacks the lingustically complex imagery of many other more suitable and amusing phrases. It lacked tact, grace, and solid satire. The content was moderately factual, and not really funny. Here at Uncyclopedia, we promote a Satirical Point of View, not a "I fucking hate all Republicans" point of view. Although the two can definitely overlap, if done well. --Famine 23:33, 30 Aug 2005 (UTC)
I wrote it. Thank you for explaining its disappearance. For the record, its 79% pent-up hostility and 21% latent homosexuality. As for how much right-wing dick sucking is too much, I'll defer to you on the subject since you seem to have a firm grasp on the topic.
Yours in Christ,
Jeff Gannon
Wow, saying that on a Liberally tilted website is sorta...retarded --Nytrospawn 13:45, 1 Sep 2005 (UTC)
I don't get that we are tilted toward the left. Maybe we are, I dunno. I see as many Gore and Clinton jokes as I do Bush jokes. I'm a registered Republican. I also happen to believe that my political party has been taken over by a bunch of sleazy crooks and religious nut cases. My actual political views are slightly more complicated than that, but suffice it to say that I think that Clinton was actually a better Republican president than Bush is, at least in terms of actions, not rhetoric. I guess that's what bothers me about the Right Wing in the USA. They are tilted over so far to the right that by their political compass, I'm a lefty. Or at least a traitor to the cause. ~MM
Can someone whip me up a right-wing dick sucker template for my user page? Humm...on second thought, skip that one. Anyway, thanks for being (seemingly) reasonable about it. Nothing personal, I whack all kinds of articles. Probably more than I should. But then again, we don't seem to be going backwards on our article count, so maybe I'm not trying hard enough. --Famine OUN Burninator 02:08, 2 Sep 2005 (UTC)
I think that the fact we're discussing politics in a serious discussion on Uncyclopedia is ironic. This place is to take a satirical point of view, not argue politics. Arguing politics is fun sometimes, but I come here to get away from that kind of stuff and just have fun. I think you'd all feel better if you didnt argue about it, I consider Uncyclopedia to be partyless anyway, the whole point is to not take anything seriously. And here I am making some stupid philosophical speech which also goes against Uncyclopedia, so I'll shut up now :P --Sir Insertwackynamehere CUN VFP 17:10, 4 Sep 2005 (UTC)
But this is the Village Dump, so you're completely welcome to be a serious and self-important blowhard, boring to death anyone you can corner. I know I do. --Marcos_Malo OUN S7fc BOotS Bur. | Talk 09:56, 5 Sep 2005 (UTC)
## Holy Cow Sophie we've spawned another
http://uncyclopedia.de/wiki/index.php/Hauptseite when will the madness end --Sir Elvis KUN FIC Bur. | Petition 00:17, 30 Aug 2005 (UTC)
## wikipedia:Wikipedia:Templates_for_deletion#Template:_Uncyclopedia
The new version of wikipedia:Template:Uncyclopedia is up for deletion again, in anyone cares, it is but a shadow of it's formed self but it may be worth saving.--Sir Elvis KUN FIC Bur. | Petition 23:53, 29 Aug 2005 (UTC)
Comment The creation of this template was not sanctioned by Uncyclopedia. Whether the consensus is to keep or delete this is up to the voters. Go vote if you want this template to stay. --stillwaters/Talk 02:03, 30 Aug 2005 (UTC)
No offense to any of you folks with dual-pedia lives, but reading that page just reminded me of what a bunch of humorless tight-asses reign over there, and why I could never write anything there, nor hang about behind the scenes. In terms of fun and friendliness, this place wins hands down. So, I really don't give a shit about what they do. By the way, is it even possible to SEE the template? --Marcos_Malo OUN S7fc BOotS Bur.</small> | Talk 03:02, 30 Aug 2005 (UTC) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 2, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.48949816823005676, "perplexity": 4796.795076795788}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-35/segments/1440646312602.99/warc/CC-MAIN-20150827033152-00135-ip-10-171-96-226.ec2.internal.warc.gz"} |
http://mathematica.stackexchange.com/questions/23990/non-linear-equation-phase-space | # Non linear equation phase space
As a supplementary to my question solution of differential equation I post a new question of how is it possible to make a Table that has elements the solutions of a non linear differential equation, so that to plot them. In a linear system you can do the following:
ss = DSolve[{x'[t] == 3 x[t], y'[t] == -y[t], x[0] == x0, y[0] == y0}, {x, y}, t];
toplot = Table[{x@t, y@t} /. ss, {x0, -0.5, 0.5, 0.25}, {y0, -0.5, 0.5, 0.25}];
ParametricPlot[Evaluate[toplot], {t, -1, 1}]
as @belisarius proposed.
If I have to use NDSolve can I use variables as above in initial conditions? I first tried the following example.
Plot[r (1 - r^2), {r, 0, 1}, AxesLabel -> {r, r'}]
ssa = NDSolve[{r'[t] == r[t] (1 - r[t]^2), u'[t] == 1, r[0] == r0,
u[0] == u0}, {r[t], u[t]}, {t, 0, 100}]
toplot = Table[{r@t Cos[u@t], r@t Sin[u@t]} /. ssa, {r0, -.5, .5, 0.25},
{u0, -.5, .5, 0.25}];
ParametricPlot[toplot, {t, 0, 100}]
The solution is what I expected, but it opened a message that said that initial condition r0 is not a number or rectangular array of numbers.
I then tried another example, it opened the same message but the solution was nearly what I wanted for some values of μ. For μ>0 the solution was OK except that it wasn't shown the second fixed point. For μ<=0 I didn't get any solution.
sol = NDSolve[{x'[t] == μ - x[t]^2, y'[t] == -y[t], x[0] == x0, y[0] == y0},
{x[t], y[t]}, {t, 0, 100}]
toplot = Table[{x@t, y@t} /. sol, {x0, -.5, 2, .25}, {y0, -.5, .5, .25}];
ParametricPlot[Evaluate[toplot], {t, 0, 100}, PlotRange -> All]
if you copy-paste the code remember to manually treat μ
The expected plots are shown bellow:
-
NDSolve cannot numerically integrate the system of equations since at this point r0 and u0 don't have numerical values. You have to wrap Table[..., {r0, ...}, {u0, ...}] around NDSolve instead of the plot curves! – István Zachar Apr 25 '13 at 5:32
Ok! I suppose that u propose me something like this: a = Table[ sol = NDSolve[{x'[t] == 1 - x[t]^2, y'[t] == -y[t], x[0] == x0, y[0] == y0}, {x[t], y[t]}, {t, 0, 100}], {x0, -.5, 5}, {y0, -.5, .5}]; After that how can I plot this table that has elements the solutions of an equation? Sorry about my question it might be elementary but now I am really confused. – 2island Apr 25 '13 at 9:47
You might also be interested in the EquationTrekker package. – Ｊ. Ｍ. May 4 '13 at 13:31
The problem is, that you call NDSolve while you haven't specified numerical values. Later, in your Table they are put in. In your second example you never say which value $\mu$ should get.
An easy way to fix this, is to make a function call out of your NDSolve. In this way it gets only evaluated when you put values in.
sol = Function[{x0, y0, mu},
NDSolve[{x'[t] == mu - x[t]^2, y'[t] == -y[t], x[0] == x0,
y[0] == y0}, {x[t], y[t]}, {t, 0, 100}]]
toplot = Table[{x@t, y@t} /. sol[x0, y0, .5], {x0, -.5,
2, .25}, {y0, -.5, .5, .25}];
ParametricPlot[Evaluate[toplot], {t, 0, 100}, PlotRange -> All]
To interpret the output is of course your job.
-
As I understand u call the NDSolve with sol[x0,y0,.5] where .5 is the value of mu (or μ). Again it doesn't work for values less than .2, I can't make plots as I posted in my question. I want μ to take values <0, =0 and >0. I know what the output should be like and what does it mean. Is there any way to make the plots as I posted above? I can't find where is the problem, the methodology seems to be right. – 2island Apr 25 '13 at 9:42
I tried another equation and it work exaclty as I a expected! Thank you very much for your answer! – 2island Apr 25 '13 at 10:01
@2island That it doesn't work with mu less than .2 is a problem of the equation and/or the numerical method used by NDSolve. You have to check yourself why it doesn't work. – halirutan Apr 25 '13 at 10:28 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5584439635276794, "perplexity": 2182.890157474753}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-41/segments/1410657134511.2/warc/CC-MAIN-20140914011214-00306-ip-10-234-18-248.ec2.internal.warc.gz"} |
https://www.expii.com/t/horizontal-asymptotes-of-rational-functions-9859 | Expii
# Horizontal Asymptotes of Rational Functions - Expii
Learn how to visualize and find the horizontal asymptotes of a rational function. A horizontal asymptote refers to "end behavior like a constant (flat line with zero slope)," which happens when the degree of the numerator is no more than the degree of the denominator. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9407891035079956, "perplexity": 316.0575212362992}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593657149205.56/warc/CC-MAIN-20200714051924-20200714081924-00598.warc.gz"} |
https://cforall.uwaterloo.ca/trac/changeset/2ebcb28d39c5081a5b63a5e1289832b9401dd1e9/doc/papers | # Changeset 2ebcb28 for doc/papers
Ignore:
Timestamp:
Jun 30, 2018, 3:56:46 PM (3 years ago)
Branches:
aaron-thesis, arm-eh, cleanup-dtors, deferred_resn, demangler, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, no_list, persistent-indexer
Children:
73de175
Parents:
Message:
Location:
doc/papers/concurrency
Files:
3 deleted
1 edited
### Legend:
Unmodified
radb60242 void print( Tree & mutex tree ) { $\C{// prefix traversal}$ // write value print( tree->left ); $\C{// multiply acquire monitor lock for tree on each recursion}$ print( tree->right ); print( *tree->left ); $\C{// multiply acquire monitor lock for tree on each recursion}$ print( *tree->right ); } \end{cfa} In \CFA, ordering of monitor acquisition relies on memory ordering to prevent deadlock~\cite{Havender68}, because all objects have distinct non-overlapping memory layouts, and mutual-exclusion for a monitor is only defined for its lifetime. When a mutex call is made, pointers to the concerned monitors are aggregated into a variable-length array and sorted. This array persists for the entire duration of the mutual-exclusion and is used extensively for synchronization operations. This array persists for the entire duration of the mutual exclusion and is used extensively for synchronization operations. To improve performance and simplicity, context switching occurs inside a routine call, so only callee-saved registers are copied onto the stack and then the stack register is switched; \end{cfa} The method used to get time is @clock_gettime( CLOCK_REALTIME )@. Each benchmark is performed @N@ times, where @N@ varies depending on the benchmark, the total time is divided by @N@ to obtain the average time for a benchmark. Each benchmark is performed @N@ times, where @N@ varies depending on the benchmark; the total time is divided by @N@ to obtain the average time for a benchmark. All omitted tests for other languages are functionally identical to the shown \CFA test. } \end{cfa} \captionof{figure}{\CFA Internal scheduling benchmark} \captionof{figure}{\CFA Internal-scheduling benchmark} \label{f:int-sched} \centering \captionof{table}{Internal scheduling comparison (nanoseconds)} \captionof{table}{Internal-scheduling comparison (nanoseconds)} \label{tab:int-sched} \bigskip } \end{cfa} \captionof{figure}{\CFA external scheduling benchmark} \captionof{figure}{\CFA external-scheduling benchmark} \label{f:ext-sched} \centering \captionof{table}{External scheduling comparison (nanoseconds)} \captionof{table}{External-scheduling comparison (nanoseconds)} \label{tab:ext-sched} \bigskip } \end{cfa} \captionof{figure}{\CFA object creation benchmark} \captionof{figure}{\CFA object-creation benchmark} \label{f:creation} | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5331153273582458, "perplexity": 22412.227697488324}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323588242.22/warc/CC-MAIN-20211027181907-20211027211907-00358.warc.gz"} |
http://www.theinfolist.com/php/SummaryGet.php?FindGo=Syllogism | Syllogism
TheInfoList
A syllogism ( grc-gre, συλλογισμός, ''syllogismos'', 'conclusion, inference') is a kind of
logical argument In logic and philosophy, an argument is a series of statements (in a natural language), called the premises or premisses (both spellings are acceptable), intended to determine the degree of truth of another statement, the conclusion. The logical ...
that applies
deductive reasoning Deductive reasoning, also deductive logic, is the process of reasoning Reason is the capacity of consciously applying logic Logic is an interdisciplinary field which studies truth and reasoning Reason is the capacity of consciously making ...
to arrive at a conclusion based on two
propositions In logic and linguistics, a proposition is the meaning of a declarative sentence (linguistics), sentence. In philosophy, "Meaning (philosophy), meaning" is understood to be a non-linguistic entity which is shared by all sentences with the same mea ...
that are asserted or assumed to be true. In its earliest form (defined by
Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher A philosopher is someone who practices philosophy Philosophy (from , ) is the study of general and fundamental quest ...
in his 350 BCE book ''
Prior Analytics The ''Prior Analytics'' ( grc-gre, Ἀναλυτικὰ Πρότερα; la, Analytica Priora) is a work by on , known as his , composed around 350 BCE. Being one of the six extant Aristotelian writings on logic and scientific method, it is pa ...
''), a syllogism arises when two true premises (propositions or statements) validly imply a conclusion, or the main point that the argument aims to get across. For example, knowing that all men are mortal (major premise) and that
Socrates Socrates (; ; –399 BC) was a Greek philosopher from Athens Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is the capital city, capital and List of cities in Greece, largest city of Greece. Athens domi ...
is a man (minor premise), we may validly conclude that Socrates is mortal. Syllogistic arguments are usually represented in a three-line form:
All men are mortal. Socrates is a man. Therefore, Socrates is mortal.
In antiquity, two rival syllogistic theories existed: Aristotelian syllogism and Stoic syllogism. From the
Middle Ages In the history of Europe The history of Europe concerns itself with the discovery and collection, the study, organization and presentation and the interpretation of past events and affairs of the people of Europe since the beginning of w ...
deductive reasoning Deductive reasoning, also deductive logic, is the process of reasoning Reason is the capacity of consciously applying logic Logic is an interdisciplinary field which studies truth and reasoning Reason is the capacity of consciously making ...
, whereby facts are determined by combining existing statements, in contrast to
inductive reasoning Inductive reasoning is a method of reasoning Reason is the capacity of Consciousness, consciously making sense of things, applying logic, and adapting or justifying practices, institutions, and beliefs based on new or existing information. It ...
in which facts are determined by repeated observations. Within an academic context, the syllogism was superseded by
first-order predicate logic First-order logic—also known as predicate logic, quantificational logic, and first-order predicate calculus—is a collection of formal system A formal system is used for inferring theorems from axioms according to a set of rules. These rules, wh ...
following the work of
Gottlob Frege Friedrich Ludwig Gottlob Frege (; ; 8 November 1848 – 26 July 1925) was a German philosopher, logician, and mathematician. He worked as a mathematics professor at the University of Jena, and is understood by many to be the father of analy ...
, in particular his ''
Begriffsschrift ''Begriffsschrift'' (German for, roughly, "concept-script") is a book on logic by Gottlob Frege, published in 1879, and the formal system set out in that book. ''Begriffsschrift'' is usually translated as ''concept writing'' or ''concept notation ...
'' (''Concept Script''; 1879). However, syllogisms remain useful in some circumstances, and for general-audience introductions to logic.
# Early history
In antiquity, two rival syllogistic theories existed: Aristotelian syllogism and Stoic syllogism. Frede, Michael. 1975. "Stoic vs. Peripatetic Syllogistic." ''Archive for the History of Philosophy'' 56:99–124.
## Aristotle
Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher A philosopher is someone who practices philosophy Philosophy (from , ) is the study of general and fundamental quest ...
defines the syllogism as "a discourse in which certain (specific) things having been supposed, something different from the things supposed results of necessity because these things are so." Despite this very general definition, in ''
Prior Analytics The ''Prior Analytics'' ( grc-gre, Ἀναλυτικὰ Πρότερα; la, Analytica Priora) is a work by on , known as his , composed around 350 BCE. Being one of the six extant Aristotelian writings on logic and scientific method, it is pa ...
'', Aristotle limits himself to categorical syllogisms that consist of three
categorical proposition In logic Logic is an interdisciplinary field which studies truth and reasoning Reason is the capacity of consciously making sense of things, applying logic Logic (from Ancient Greek, Greek: grc, wikt:λογική, λογική, label= ...
s, including categorical modal syllogisms. The use of syllogisms as a tool for understanding can be dated back to the logical reasoning discussions of
Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher A philosopher is someone who practices philosophy Philosophy (from , ) is the study of general and fundamental quest ...
. Before the mid-12th century, medieval logicians were only familiar with a portion of Aristotle's works, including such titles as ''
Categories Category, plural categories, may refer to: Philosophy and general uses *Categorization Categorization is the human ability and activity of recognizing shared features or similarities between the elements of the experience of the world (such ...
'' and ''
On Interpretation ''De Interpretatione'' or ''On Interpretation'' (Ancient Greek, Greek: Περὶ Ἑρμηνείας, ''Peri Hermeneias'') is the second text from Aristotle's ''Organon'' and is among the earliest surviving philosophical works in the Western phil ...
'', works that contributed heavily to the prevailing Old Logic, or ''
logica vetus In the history of logic, the term ''logica nova'' (Latin, meaning "new logic") refers to a subdivision of the logical tradition of Western Europe, as it existed around the middle of the twelfth century. According to the availability at the time of t ...
''. The onset of a New Logic, or ''
logica nova In the history of logic The history of logic deals with the study of the development of the science of valid inference Inferences are steps in reasoning, moving from premises to logical consequences; etymologically, the word ''wikt:infer, infe ...
'', arose alongside the reappearance of ''Prior Analytics'', the work in which Aristotle developed his theory of the syllogism. ''Prior Analytics'', upon rediscovery, was instantly regarded by logicians as "a closed and complete body of doctrine," leaving very little for thinkers of the day to debate and reorganize. Aristotle's theory on the syllogism for ''
assertoricAn assertoric proposition in Aristotelianism, Aristotelian logic merely asserts that something is (or is not) the case, in contrast to problematic propositions which assert the possibility of something being true, or apodeictic propositions which ass ...
'' sentences was considered especially remarkable, with only small systematic changes occurring to the concept over time. This theory of the syllogism would not enter the context of the more comprehensive logic of consequence until logic began to be reworked in general in the mid-14th century by the likes of
John Buridan Jean Buridan (; Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman ...
. Aristotle's ''Prior Analytics'' did not, however, incorporate such a comprehensive theory on the modal syllogism—a syllogism that has at least one modalized premise, that is, a premise containing the modal words 'necessarily', 'possibly', or 'contingently'. Aristotle's terminology, in this aspect of his theory, was deemed vague and in many cases unclear, even contradicting some of his statements from ''On Interpretation''. His original assertions on this specific component of the theory were left up to a considerable amount of conversation, resulting in a wide array of solutions put forth by commentators of the day. The system for modal syllogisms laid forth by Aristotle would ultimately be deemed unfit for practical use and would be replaced by new distinctions and new theories altogether.
## Medieval syllogism
### Boethius
Boethius Anicius Manlius Severinus Boëthius, commonly called Boethius (; also Boetius ; 477 – 524 AD), was a Roman Roman Senate, senator, Roman consul, consul, ''magister officiorum'', and philosopher of the early 6th century. He was born about a ye ...
(c. 475–526) contributed an effort to make the ancient Aristotelian logic more accessible. While his Latin translation of ''
Prior Analytics The ''Prior Analytics'' ( grc-gre, Ἀναλυτικὰ Πρότερα; la, Analytica Priora) is a work by on , known as his , composed around 350 BCE. Being one of the six extant Aristotelian writings on logic and scientific method, it is pa ...
'' went primarily unused before the 12th century, his textbooks on the categorical syllogism were central to expanding the syllogistic discussion. Rather than in any additions that he personally made to the field, Boethius's logical legacy lies in his effective transmission of prior theories to later logicians, as well as his clear and primarily accurate presentations of Aristotle's contributions.
### Peter Abelard
Another of medieval logic's first contributors from the Latin West,
Peter Abelard Peter Abelard (; french: link=no, Pierre Abélard; la, Petrus Abaelardus or ''Abailardus''; 21 April 1142) was a medieval In the history of Europe The history of Europe concerns itself with the discovery and collection, the study, or ...
(1079–1142), gave his own thorough evaluation of the syllogism concept and accompanying theory in the ''Dialectica''—a discussion of logic based on Boethius's commentaries and monographs. His perspective on syllogisms can be found in other works as well, such as ''Logica Ingredientibus''. With the help of Abelard's distinction between ''
de dicto ''De dicto'' and ''de re'' are two phrases used to mark a distinction in intensional statements, associated with the intensional operators in many such statements. The distinction is used regularly in metaphysics and in philosophy of language. The ...
'' modal sentences and ''de re'' modal sentences, medieval logicians began to shape a more coherent concept of Aristotle's modal syllogism model.
### Jean Buridan
The French philosopher Jean Buridan (c. 1300 – 1361), whom some consider the foremost logician of the later Middle Ages, contributed two significant works: ''Treatise on Consequence'' and ''Summulae de Dialectica'', in which he discussed the concept of the syllogism, its components and distinctions, and ways to use the tool to expand its logical capability. For 200 years after Buridan's discussions, little was said about syllogistic logic. Historians of logic have assessed that the primary changes in the post-Middle Age era were changes in respect to the public's awareness of original sources, a lessening of appreciation for the logic's sophistication and complexity, and an increase in logical ignorance—so that logicians of the early 20th century came to view the whole system as ridiculous.
# Modern history
The Aristotelian syllogism dominated Western philosophical thought for many centuries. Syllogism itself is about drawing valid conclusions from assumptions (axioms), rather than about verifying the assumptions. However, people over time focused on the logic aspect, forgetting the importance of verifying the assumptions. In the 17th century, Francis Bacon emphasized that experimental verification of axioms must be carried out rigorously, and cannot take syllogism itself as the best way to draw conclusions in nature.Francis Bacon, Bacon, Francis. [1620] 2001.
The Great Instauration
'. – via ''The Constitution Society, Constitution Society''. Archived from th
original
on 13 April 2019.
Bacon proposed a more inductive approach to the observation of nature, which involves experimentation and leads to discovering and building on axioms to create a more general conclusion. Yet, a full method of drawing conclusions in nature is not the scope of logic or syllogism, and the inductive method was covered in Aristotle's subsequent treatise, the ''Posterior Analytics''. In the 19th century, modifications to syllogism were incorporated to deal with Disjunctive syllogism, disjunctive ("A or B") and Conditional syllogism, conditional ("if A then B") statements. Immanuel Kant famously claimed, in ''Logic'' (1800), that logic was the one completed science, and that Aristotelian logic more or less included everything about logic that there was to know. (This work is not necessarily representative of Kant's mature philosophy, which is often regarded as an innovation to logic itself.) Although there were alternative systems of logic elsewhere, such as Logic in Islamic philosophy, Avicennian logic or Indian logic, Kant's opinion stood unchallenged in the West until 1879, when
Gottlob Frege Friedrich Ludwig Gottlob Frege (; ; 8 November 1848 – 26 July 1925) was a German philosopher, logician, and mathematician. He worked as a mathematics professor at the University of Jena, and is understood by many to be the father of analy ...
published his ''
Begriffsschrift ''Begriffsschrift'' (German for, roughly, "concept-script") is a book on logic by Gottlob Frege, published in 1879, and the formal system set out in that book. ''Begriffsschrift'' is usually translated as ''concept writing'' or ''concept notation ...
'' (''Concept Script''). This introduced a calculus, a method of representing categorical statements (and statements that are not provided for in syllogism as well) by the use of quantifiers and variables. A noteworthy exception is the logic developed in Bernard Bolzano's work ''Bernard Bolzano#Wissenschaftslehre (Theory of Science), Wissenschaftslehre'' (''Theory of Science'', 1837), the principles of which were applied as a direct critique of Kant, in the posthumously published work ''New Anti-Kant'' (1850). The work of Bolzano had been largely overlooked until the late 20th century, among other reasons, because of the intellectual environment at the time in Bohemia, which was then part of the Austrian Empire. In the last 20 years, Bolzano's work has resurfaced and become subject of both translation and contemporary study. This led to the rapid development of sentential logic and first-order predicate logic, subsuming syllogistic reasoning, which was, therefore, after 2000 years, suddenly considered obsolete by many. The Aristotelian system is explicated in modern fora of academia primarily in introductory material and historical study. One notable exception to this modern relegation is the continued application of Aristotelian logic by officials of the Congregation for the Doctrine of the Faith, and the Apostolic Tribunal of the Roman Rota, which still requires that any arguments crafted by Advocates be presented in syllogistic format.
## Boole's acceptance of Aristotle
George Boole's unwavering acceptance of Aristotle's logic is emphasized by the historian of logic John Corcoran (logician), John Corcoran in an accessible introduction to ''Laws of Thought''. Corcoran also wrote a point-by-point comparison of ''
Prior Analytics The ''Prior Analytics'' ( grc-gre, Ἀναλυτικὰ Πρότερα; la, Analytica Priora) is a work by on , known as his , composed around 350 BCE. Being one of the six extant Aristotelian writings on logic and scientific method, it is pa ...
'' and ''The Laws of Thought, Laws of Thought''.John Corcoran (logician), Corcoran, John. 2003. "Aristotle's 'Prior Analytics' and Boole's 'Laws of Thought'." ''History and Philosophy of Logic'' 24:261–88. According to Corcoran, Boole fully accepted and endorsed Aristotle's logic. Boole's goals were "to go under, over, and beyond" Aristotle's logic by: # providing it with mathematical foundations involving equations; # extending the class of problems it could treat, as solving equations was added to assessing Validity (logic), validity; and # expanding the range of applications it could handle, such as expanding propositions of only two terms to those having arbitrarily many. More specifically, Boole agreed with what
Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher A philosopher is someone who practices philosophy Philosophy (from , ) is the study of general and fundamental quest ...
said; Boole's 'disagreements', if they might be called that, concern what Aristotle did not say. First, in the realm of foundations, Boole reduced Aristotle's four propositional forms to one form, the form of equations, which by itself was a revolutionary idea. Second, in the realm of logic's problems, Boole's addition of equation solving to logic—another revolutionary idea—involved Boole's doctrine that Aristotle's rules of inference (the "perfect syllogisms") must be supplemented by rules for equation solving. Third, in the realm of applications, Boole's system could handle multi-term propositions and arguments, whereas Aristotle could handle only two-termed subject-predicate propositions and arguments. For example, Aristotle's system could not deduce: "No quadrangle that is a square is a rectangle that is a rhombus" from "No square that is a quadrangle is a rhombus that is a rectangle" or from "No rhombus that is a rectangle is a square that is a quadrangle."
# Basic structure
A categorical syllogism consists of three parts: # Major premise # Minor premise # Conclusion Each part is a
categorical proposition In logic Logic is an interdisciplinary field which studies truth and reasoning Reason is the capacity of consciously making sense of things, applying logic Logic (from Ancient Greek, Greek: grc, wikt:λογική, λογική, label= ...
, and each categorical proposition contains two categorical terms. In Aristotle, each of the premises is in the form "All A are B," "Some A are B", "No A are B" or "Some A are not B", where "A" is one term and "B" is another: * "All A are B," and "No A are B" are termed Universal proposition, ''universal'' propositions; * "Some A are B" and "Some A are not B" are termed Particular proposition, ''particular'' propositions. More modern logicians allow some variation. Each of the premises has one term in common with the conclusion: in a major premise, this is the ''major term'' (i.e., the Predicate (grammar), predicate of the conclusion); in a minor premise, this is the ''minor term'' (i.e., the subject of the conclusion). For example: :Major premise: All humans are mortal. :Minor premise: All Greeks are humans. :Conclusion: All Greeks are mortal. Each of the three distinct terms represents a category. From the example above, ''humans'', ''mortal'', and ''Greeks'': ''mortal'' is the major term, and ''Greeks'' the minor term. The premises also have one term in common with each other, which is known as the ''middle term''; in this example, ''humans''. Both of the premises are universal, as is the conclusion. :Major premise: All mortals die. :Minor premise: All men are mortals. :Conclusion: All men die. Here, the major term is ''die'', the minor term is ''men'', and the middle term is ''mortals''. Again, both premises are universal, hence so is the conclusion.
## Polysyllogism
A polysyllogism, or a sorites, is a form of argument in which a series of incomplete syllogisms is so arranged that the predicate of each premise forms the subject of the next until the subject of the first is joined with the predicate of the last in the conclusion. For example, one might argue that all lions are big cats, all big cats are predators, and all predators are carnivores. To conclude that therefore all lions are carnivores is to construct a sorites argument.
# Types
There are infinitely many possible syllogisms, but only 256 logically distinct types and only 24 valid types (enumerated below). A syllogism takes the form (note: M – Middle, S – subject, P – predicate.): :Major premise: All M are P. :Minor premise: All S are M. :Conclusion: All S are P. The premises and conclusion of a syllogism can be any of four types, which are labeled by letters as follows. The meaning of the letters is given by the table: In ''
Prior Analytics The ''Prior Analytics'' ( grc-gre, Ἀναλυτικὰ Πρότερα; la, Analytica Priora) is a work by on , known as his , composed around 350 BCE. Being one of the six extant Aristotelian writings on logic and scientific method, it is pa ...
'', Aristotle uses mostly the letters A, B, and C (Greek letters ''alpha'', ''beta'', and ''gamma'') as term place holders, rather than giving concrete examples. It is traditional to use ''is'' rather than ''are'' as the Copula (linguistics), copula, hence ''All A is B'' rather than ''All As are Bs''. It is traditional and convenient practice to use a, e, i, o as Infix notation, infix operators so the categorical statements can be written succinctly. The following table shows the longer form, the succinct shorthand, and equivalent expressions in predicate logic: The convention here is that the letter S is the subject of the conclusion, P is the predicate of the conclusion, and M is the middle term. The major premise links M with P and the minor premise links M with S. However, the middle term can be either the subject or the predicate of each premise where it appears. The differing positions of the major, minor, and middle terms gives rise to another classification of syllogisms known as the ''figure''. Given that in each case the conclusion is S-P, the four figures are: (Note, however, that, following Aristotle's treatment of the figures, some logicians—e.g.,
Peter Abelard Peter Abelard (; french: link=no, Pierre Abélard; la, Petrus Abaelardus or ''Abailardus''; 21 April 1142) was a medieval In the history of Europe The history of Europe concerns itself with the discovery and collection, the study, or ...
and Jean Buridan—reject the fourth figure as a figure distinct from the first.) Putting it all together, there are 256 possible types of syllogisms (or 512 if the order of the major and minor premises is changed, though this makes no difference logically). Each premise and the conclusion can be of type A, E, I or O, and the syllogism can be any of the four figures. A syllogism can be described briefly by giving the letters for the premises and conclusion followed by the number for the figure. For example, the syllogism BARBARA below is AAA-1, or "A-A-A in the first figure". The vast majority of the 256 possible forms of syllogism are invalid (the conclusion does not logical consequence, follow logically from the premises). The table below shows the valid forms. Even some of these are sometimes considered to commit the existential fallacy, meaning they are invalid if they mention an empty category. These controversial patterns are marked in ''italics''. All but four of the patterns in italics (felapton, darapti, fesapo and bamalip) are weakened moods, i.e. it is possible to draw a stronger conclusion from the premises. e ''Fig. 1, treble clef. "A syllogism's letters can be best represented in music— take E, for example." -Marilyn Damord'' The letters A, E, I, and O have been used since the Scholasticism, medieval Schools to form mnemonic names for the forms as follows: 'Barbara' stands for AAA, 'Celarent' for EAE, etc. Next to each premise and conclusion is a shorthand description of the sentence. So in AAI-3, the premise "All squares are rectangles" becomes "MaP"; the symbols mean that the first term ("square") is the middle term, the second term ("rectangle") is the predicate of the conclusion, and the relationship between the two terms is labeled "a" (All M are P). The following table shows all syllogisms that are essentially different. The similar syllogisms share the same premises, just written in a different way. For example "Some pets are kittens" (SiM in #Darii (AII-1), Darii) could also be written as "Some kittens are pets" (MiS in Datisi). In the Venn diagrams, the black areas indicate no elements, and the red areas indicate at least one element. In the predicate logic expressions, a horizontal bar over an expression means to negate ("logical not") the result of that expression. It is also possible to use graph (discrete mathematics), graphs (consisting of vertices and edges) to evaluate syllogisms.
## Examples
### Celarent (EAE-1)
Similar: Cesare (EAE-2)
### Darii (AII-1)
Similar: Datisi (AII-3)
### Ferio (EIO-1)
Similar: Festino (EIO-2), Ferison (EIO-3), Fresison (EIO-4)
----
### ''Celaront (EAO-1)''
Similar: ''Cesaro (EAO-2)''
### ''Camestros (AEO-2)''
Similar: ''Calemos (AEO-4)''
### ''Felapton (EAO-3)''
Similar: ''Fesapo (EAO-4)''
## Table of all syllogisms
This table shows all 24 valid syllogisms, represented by Venn diagrams. Columns indicate similarity, and are grouped by combinations of premises. Borders correspond to conclusions. Those with an existential assumption are dashed.
# Terms in syllogism
With Aristotle, we may distinguish singular terms, such as ''Socrates'', and general terms, such as ''Greeks''. Aristotle further distinguished types (a) and (b): Such a predication is known as a Distributive (linguistics), distributive, as opposed to non-distributive as in ''Greeks are numerous''. It is clear that Aristotle's syllogism works only for distributive predication, since we cannot reason ''All Greeks are animals, animals are numerous, therefore all Greeks are numerous''. In Aristotle's view singular terms were of type (a), and general terms of type (b). Thus, ''Men'' can be predicated of ''Socrates'' but ''Socrates'' cannot be predicated of anything. Therefore, for a term to be interchangeable—to be either in the subject or predicate position of a proposition in a syllogism—the terms must be general terms, or ''categorical terms'' as they came to be called. Consequently, the propositions of a syllogism should be categorical propositions (both terms general) and syllogisms that employ only categorical terms came to be called ''categorical syllogisms''. It is clear that nothing would prevent a singular term occurring in a syllogism—so long as it was always in the subject position—however, such a syllogism, even if valid, is not a categorical syllogism. An example is ''Socrates is a man, all men are mortal, therefore Socrates is mortal.'' Intuitively this is as valid as ''All Greeks are men, all men are mortal therefore all Greeks are mortals''. To argue that its validity can be explained by the theory of syllogism would require that we show that ''Socrates is a man'' is the equivalent of a categorical proposition. It can be argued ''Socrates is a man'' is equivalent to ''All that are identical to Socrates are men'', so our non-categorical syllogism can be justified by use of the equivalence above and then citing BARBARA.
# Existential import
If a statement includes a term such that the statement is false if the term has no instances, then the statement is said to have ''existential import'' with respect to that term. It is ambiguous whether or not a universal statement of the form ''All A is B'' is to be considered as true, false, or even meaningless if there are no As. If it is considered as false in such cases, then the statement ''All A is B'' has existential import with respect to A. It is claimed Aristotle's logic system does not cover cases where there are no instances. Aristotle's goal was to develop "a companion-logic for science. He relegates fictions, such as mermaids and unicorns, to the realms of poetry and literature. In his mind, they exist outside the ambit of science. This is why he leaves no room for such non-existent entities in his logic. This is a thoughtful choice, not an inadvertent omission. Technically, Aristotelian science is a search for definitions, where a definition is 'a phrase signifying a thing's essence.'... Because non-existent entities cannot be anything, they do not, in Aristotle's mind, possess an essence... This is why he leaves no place for fictional entities like goat-stags (or unicorns)." However, many logic systems developed since ''do'' consider the case where there may be no instances. However, medieval logicians were aware of the problem of existential import and maintained that negative propositions do not carry existential import, and that positive propositions with subjects that do not supposition theory, supposit are false. The following problems arise: For example, if it is accepted that AiB is false if there are no As and AaB entails AiB, then AiB has existential import with respect to A, and so does AaB. Further, if it is accepted that AiB entails BiA, then AiB and AaB have existential import with respect to B as well. Similarly, if AoB is false if there are no As, and AeB entails AoB, and AeB entails BeA (which in turn entails BoA) then both AeB and AoB have existential import with respect to both A and B. It follows immediately that all universal categorical statements have existential import with respect to both terms. If AaB and AeB is a fair representation of the use of statements in normal natural language of All A is B and No A is B respectively, then the following example consequences arise: :"All flying horses are mythical" is false if there are no flying horses. :If "No men are fire-eating rabbits" is true, then "There are fire-eating rabbits" is true; and so on. If it is ruled that no universal statement has existential import then the square of opposition fails in several respects (e.g. AaB does not entail AiB) and a number of syllogisms are no longer valid (e.g. BaC,AaB->AiC). These problems and paradoxes arise in both natural language statements and statements in syllogism form because of ambiguity, in particular ambiguity with respect to All. If "Fred claims all his books were Pulitzer Prize winners", is Fred claiming that he wrote any books? If not, then is what he claims true? Suppose Jane says none of her friends are poor; is that true if she has no friends? The first-order predicate calculus avoids such ambiguity by using formulae that carry no existential import with respect to universal statements. Existential claims must be explicitly stated. Thus, natural language statements—of the forms ''All A is B, No A is B'', ''Some A is B'', and ''Some A is not B''—can be represented in first order predicate calculus in which any existential import with respect to terms A and/or B is either explicit or not made at all. Consequently, the four forms ''AaB, AeB, AiB'', and ''AoB'' can be represented in first order predicate in every combination of existential import—so it can establish which construal, if any, preserves the square of opposition and the validity of the traditionally valid syllogism. Strawson claims such a construal is possible, but the results are such that, in his view, the answer to question (e) above is ''no''. On the other hand, in modern mathematical logic, however, statements containing words "all", "some" and "no", can be stated in terms of set theory. If the set of all A's is labeled as $s\left(A\right)$ and the set of all B's as $s\left(B\right)$, then: * "All A is B" (AaB) is equivalent to "$s\left(A\right)$ is a subset of $s\left(B\right)$", or $s\left(A\right) \subseteq s\left(B\right)$. * "No A is B" (AeB) is equivalent to "The intersection of $s\left(A\right)$ and $s\left(B\right)$ is Empty set, empty", or $s\left(A\right) \cap s\left(B\right) = \empty$. * "Some A is B" (AiB) is equivalent to "The intersection of $s\left(A\right)$ and $s\left(B\right)$ is not empty", or $s\left(A\right) \cap s\left(B\right) \neq \empty$. * "Some A is not B" (AoB) is equivalent to "$s\left(A\right)$ is not a subset of $s\left(B\right)$", or $s\left(A\right) \nsubseteq s\left(B\right)$. By definition, the empty set $\empty$ is a subset of all sets. From this fact it follows that, according to this mathematical convention, if there are no A's, then the statements "All A is B" and "No A is B" are always true whereas the statements "Some A is B" and "Some A is not B" are always false. This also implies that AaB does not entail AiB, and some of the syllogisms mentioned above are not valid when there are no A's ($s\left(A\right) = \empty$).
# Syllogistic fallacies
People often make mistakes when reasoning syllogistically. For instance, from the premises some A are B, some B are C, people tend to come to a definitive conclusion that therefore some A are C. However, this does not follow according to the rules of classical logic. For instance, while some cats (A) are black things (B), and some black things (B) are televisions (C), it does not follow from the parameters that some cats (A) are televisions (C). This is because in the structure of the syllogism invoked (i.e. III-1) the middle term is not distributed in either the major premise or in the minor premise, a pattern called the "fallacy of the undistributed middle". Because of this, it can be hard to follow formal logic, and a closer eye is needed in order to ensure that an argument is, in fact, valid. Determining the validity of a syllogism involves determining the distribution of terms, distribution of each term in each statement, meaning whether all members of that term are accounted for. In simple syllogistic patterns, the fallacies of invalid patterns are: *Fallacy of the undistributed middle, Undistributed middle: Neither of the premises accounts for all members of the middle term, which consequently fails to link the major and minor term. *Illicit major, Illicit treatment of the major term: The conclusion implicates all members of the major term (P – meaning the proposition is negative); however, the major premise does not account for them all (i.e., P is either an affirmative predicate or a particular subject there). *Illicit minor, Illicit treatment of the minor term: Same as above, but for the minor term (S – meaning the proposition is universal) and minor premise (where S is either a particular subject or an affirmative predicate). *Fallacy of exclusive premises, Exclusive premises: Both premises are negative, meaning no link is established between the major and minor terms. *Affirmative conclusion from a negative premise: If either premise is negative, the conclusion must also be. *Negative conclusion from affirmative premises: If both premises are affirmative, the conclusion must also be.
# Other types of syllogism
*Disjunctive syllogism *Hypothetical syllogism *Legal syllogism *Polysyllogism *Prosleptic syllogism *Quasi-syllogism *Statistical syllogism
*Syllogistic fallacy * Argumentation theory#Psychological aspects, Argumentation theory * Buddhist logic * Enthymeme * Formal fallacy * Logical fallacy * The False Subtlety of the Four Syllogistic Figures * Tautology (logic) * Venn diagram
# References
## Sources
*
Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher A philosopher is someone who practices philosophy Philosophy (from , ) is the study of general and fundamental quest ...
, [c. 350 BCE] 1989. ''
Prior Analytics The ''Prior Analytics'' ( grc-gre, Ἀναλυτικὰ Πρότερα; la, Analytica Priora) is a work by on , known as his , composed around 350 BCE. Being one of the six extant Aristotelian writings on logic and scientific method, it is pa ...
'', translated by R. Smith. Hackett. *Simon Blackburn, Blackburn, Simon. [1994] 1996. "Syllogism." In The Oxford Dictionary of Philosophy, ''The'' ''Oxford Dictionary of Philosophy''. Oxford University Press. . * Broadie, Alexander. 1993. ''Introduction to Medieval Logic''. Oxford University Press. . *Irving Copi, Copi, Irving. 1969. ''Introduction to Logic'' (3rd ed.). Macmillan Company. *John Corcoran (logician), Corcoran, John. 1972. "Completeness of an ancient logic." ''Journal of Symbolic Logic'' 37:696–702. * — 1994. "The founding of logic: Modern interpretations of Aristotle's logic." ''Ancient Philosophy (journal), Ancient Philosophy'' 14:9–24. * Corcoran, John, and Hassan Masoud. 2015. "Existential Import Today: New Metatheorems; Historical, Philosophical, and Pedagogical Misconceptions." ''History and Philosophy of Logic'' 36(1):39–61. * Englebretsen, George. 1987. ''The New Syllogistic''. Bern: Peter Lang (publisher), Peter Lang. *Charles Leonard Hamblin, Hamblin, Charles Leonard. 1970. ''Fallacies''. London: Methuen Publishing, Methuen. . **Cf. on validity of syllogisms: "A simple set of rules of validity was finally produced in the later Middle Ages, based on the concept of Distribution." *Jan Łukasiewicz, Łukasiewicz, Jan. [1957] 1987. ''Aristotle's Syllogistic from the Standpoint of Modern Formal Logic''. New York: Garland Publishers. . . * Malink, Marko. 2013. ''Aristotle's Modal Syllogistic''. Cambridge, MA: Harvard University Press. * Patzig, Günter. 1968. ''Aristotle's theory of the syllogism: a logico-philological study of Book A of the Prior Analytics''. Dordrecht: Reidel. * Rescher, Nicholas. 1966. ''Galen and the Syllogism''. University of Pittsburgh Press. . * Timothy Smiley, Smiley, Timothy. 1973. "What is a syllogism?" ''Journal of Philosophical Logic'' 2:136–54. * Smith, Robin. 1986. "Immediate propositions and Aristotle's proof theory." ''Ancient Philosophy'' 6:47–68. * Thom, Paul. 1981. "The Syllogism." ''Philosophia (journal), Philosophia''. München. .
* * Koutsoukou-Argyraki, Angeliki
Aristotle's Assertoric Syllogistic (Formal proof development in Isabelle/HOL, Archive of Formal Proofs)
*
an annotated bibliography on Aristotle's syllogistic
Fuzzy Syllogistic System
Development of Fuzzy Syllogistic Algorithms and Applications Distributed Reasoning Approaches
Comparison between the Aristotelian Syllogism and the Indian/Tibetan Syllogism
* [http://www.thefirstscience.org/syllogistic/ Online Syllogistic Machine] An interactive syllogistic machine for exploring all the fallacies, figures, terms, and modes of syllogisms. {{Authority control Syllogism, Term logic Arguments | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 16, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7615196108818054, "perplexity": 3812.5038894314416}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320304959.80/warc/CC-MAIN-20220126162115-20220126192115-00032.warc.gz"} |
https://hal-amu.archives-ouvertes.fr/hal-01840679 | Power spectrum of the cosmic infrared background at 60 and 100 μ m with IRAS - Archive ouverte HAL Access content directly
Journal Articles Astronomy and Astrophysics - A&A Year : 2002
## Power spectrum of the cosmic infrared background at 60 and 100 μ m with IRAS
M.-A. Miville-Deschênes
Guilaine Lagache
J.-L. Puget
• Function : Author
#### Abstract
Based on a power spectrum analysis of the IRAS ISSA maps, we present the first detection of the Cosmic far-Infrared Background (CIB) fluctuations at 60 and 100 µm. The power spectrum of 12 low cirrus emission regions is characterized by a power excess at spatial frequencies higher than k ∼ 0.02 arcmin −1. Most of this excess is due to noise and to nearby point sources with a flux stronger than 1 Jy. But we show that when these contributions are carefully removed, there is still a power excess that is the signature of the CIB fluctuations. The power spectrum of the CIB at 60 and 100 µm is compatible with a Poissonian distribution, at spatial frequencies between 0.025 and 0.2 arcmin −1. The fluctuation level is ∼1.6 × 10 3 Jy 2 /sr and ∼5.8 × 10 3 Jy 2 /sr at 60 and 100 µm respectively. The levels of the fluctuations are used in a larger framework, with other observationnal data, to constrain the evolution of IR galaxies (Lagache et al. 2002). The detections reported here, coupled with the level of the fluctuations at 170 µm, give strong constraints on the evolution of the IR luminosity function. The combined results at 60, 100 and 170 µm for the CIB and its fluctuations allows, on the CIB at 60 µm, to put a firm upper limit of 0.27 MJy/sr and to give an estimate of 0.18 MJy/sr.
### Dates and versions
hal-01840679 , version 1 (16-07-2018)
### Identifiers
• HAL Id : hal-01840679 , version 1
• DOI :
### Cite
M.-A. Miville-Deschênes, Guilaine Lagache, J.-L. Puget. Power spectrum of the cosmic infrared background at 60 and 100 μ m with IRAS. Astronomy and Astrophysics - A&A, 2002, 393 (3), pp.749 - 756. ⟨10.1051/0004-6361:20020929⟩. ⟨hal-01840679⟩
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http://www.checkmyknowledge.com/a-level/physics/training/a2/thermal-energy | ###### Boyle's law
Select the correct statement of Boyle's law.
Select the correct answer.
For a constant mass of gas at a constant temperature, the pressure exerted by the gas is inversely proportional to the volume it occupies.
###### Charles's law
Select the correct statement of Charles's law.
Select the correct statement.
For a constant mass of gas at a constant pressure, the volume occupied by the gas is proportional to its absolute temperature.
###### Absolute zero
Select the correct definition of absolute zero temperature.
Select the correct answer.
Absolute zero is the temperature at which the pressure of an ideal gas becomes zero. This is 0К on the Kelvin temperature scale, which is equivalent to -273 °C.
###### Absolute temperature
Select the correct definition of absolute temperature.
Select the correct answer.
Absolute temperature is the Kelvin or thermodynamic temperature scale with zero at -273 °C, the temperature at which the pressure of an ideal gas becomes zero.
###### Specific heat capacity
How long will a 1.5 kW kettle take to raise the temperature of 1kg of water from 20° C to 100° C? The specific heat capacity of water is $$4200{J\over kg\times K}$$.
Select the correct answer.
$$\Delta \theta=100-20 = 80K$$
$$\Delta E = c m \Delta T = 4200*1*80=336000J$$
$$\Delta t=E/P=336000/1500=224s$$
###### RMS speed
Find the r.m.s. speed of the five molecules of atmospheric oxygen. Velocities of the molecules are: v1 = 500 m/s, v2 = 496 m/s, v3 = 508 m/s, v4 = 503 m/s, v5 = 499 m/s.
Select the correct answer.
The root-mean-square speed $$c=\sqrt{v^2_1+v^2_2+v^2_3+v^2_4+v^2_5\over 5}\approx501.217m/s$$.
###### RMS speed - 2
What is the root-mean-square speed of a balloon filled with dioxygen at 20° C? The mass of a dioxygen miolecule is $$5.312\times10^{-26} kg$$.
Select the correct answer.
$$T = 20+273 =293K$$
$${m<c^2>\over2}={3\over2}kT$$
Root-mean-square speed is $$\sqrt{<c^2>}=\sqrt{3kT \over m}\approx477.865m/s$$
###### Pressure law
Select the correct definition of pressure law.
Select the correct option.
For a constant mass of gas at a constant volume, the pressure exerted by the gas is proportional to its absolute temperature.
###### Equation of state
Select the correct expression for the equation of state for an ideal gas.
Select the correct option.
The equation of state for an ideal gas is $$pV=nRT$$. It relates the pressure, volume and temperature of an ideal gas. n is the number of moles of the gas; and R is the Universal gas constant. $$R = 8.31{J\over kg\times mol}$$.
###### Ideal gas
Which of the features listed are wrong for an ideal gas?
Select only wrong options.
An ideal gas would have the following properties:
1 The molecules have zero size.
2 The molecules are identical.
3 The molecules collide with each other and the walls of their containers without any loss of energy, collisions take zero time.
4 The molecules exert no forces on each other, except during collisions.
5 There are enough molecules for statistical laws to be applied. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9750916957855225, "perplexity": 1272.0252813413613}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128321961.50/warc/CC-MAIN-20170627235941-20170628015941-00592.warc.gz"} |
https://math.stackexchange.com/questions/1742848/what-is-condition-for-second-degree-equation-to-represent-a-pair-of-straight-lin | # What is condition for second degree equation to represent a pair of straight lines?
According to my text the necessary and sufficient condition for a general equation of second degree i.e. $ax^2 + 2hxy + by^2 + 2gx + 2fy + c = 0$ to represent a pair of straight lines is that 1) the discriminant $abc + 2fgh - af^2 - bg^2 - cf^2 = 0$ and 2) $h^2 \ge ab, g^2 \ge ca$ and $f^2 \ge bc$. I was able to prove part 1) but I am not able to work out why part 2) should always be satisfied. Can someone help prove part 2) and what happens if part 1) is true but part 2) is false?
I think $h^2 \ge ab$ must always be true because then angle between two lines represented by the equation of second degree will be not defined as $tan \theta = {2 \sqrt{h^2-ab} \over a+b}$ where $\theta$ is angle between two lines.
• With $h^2<ab$, the trinomial formed by the quadratic terms is positive (or negative) definite, hence the conic is of the ellipse type. – Yves Daoust Apr 14 '16 at 20:38
If the conic represents a pair of lines, then it can be written as $(px+qy+r)(p'x+q'y+r')$. Therefore, we get $ab = pp'qq'$ and $h = \frac{pq'+p'q}{2}$.
1) If both $pq'$ and $p'q$ are greater than equal to zero then apply AM-GM to $pq'$ and $p'q$ to get
$$\frac{pq'+ p'q}{2} \geq \sqrt{pq' \cdot p'q}$$
Squaring both sides, we get
$$h^2 = {\bigg(\frac{pq'+ p'q}{2}\bigg)}^2 \geq pp'qq' = ab$$
2) If exactly one of $pq'$ and $p'q$ is less than zero then $ab \leq 0$ and therefore is always less than equal to $h^2 \geq 0$.
3) If both $pq'$ and $p'q$ are less than zero then apply AM-GM to $-pq'$ and $-p'q$ to get
$$\frac{-pq'+ (-p'q)}{2} \geq \sqrt{-pq' \cdot -p'q} = \sqrt{pp'qq'}$$
Squaring both sides, we get
$$h^2 = {\bigg(\frac{-pq'+ (-p'q)}{2}\bigg)}^2 \geq pp'qq' = ab$$
The other two conditions come out in a similar manner.
• thanks that was pretty easy.! – Matt Apr 14 '16 at 21:04
• I realized that we can't quite apply AM-GM since $a$ and $b$ need not be positive in general. But in that case, $ab \leq 0$ and is hence less than equal to the square $h^2$. – Seven Apr 14 '16 at 21:11
• may you please show how can we prove any one of three by A.M G.M inequality? – Matt Apr 15 '16 at 17:11
• @Raghav I have elaborated on the answer. Hope that helps. – Seven Apr 15 '16 at 20:36
Hint:
The classification of conics is done through the quadratic form in $\mathbf R^3$ associated to the matrix $$\begin{pmatrix} a&h&g\\h&b&f\\g&f&c \end{pmatrix}.$$ The conic splits into two lines if and only if the quadratic form has signature $(1,1)$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8925583958625793, "perplexity": 130.62256375443528}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195529481.73/warc/CC-MAIN-20190723172209-20190723194209-00539.warc.gz"} |
https://engineering.stackexchange.com/questions/5913/how-do-you-find-this-vx-in-the-given-circuit | # How do you find “this” Vx in the given circuit?
So I was told that $V_x$ is equal to 10V. I tried reasoning out why $V_x$ was 10V and this is what I got:
-You can treat the Vx as an open circuit which means current does not flow through the resistor (meaning it's a short circuit) and thus from KVL we get $V_x$ = 10V
However, I am still not convinced that $V_x$= 10V. A better explanation would be greatly appreciated.
• Welcome to Engineering SE. You are asked to calculate $V_{th}$ for the circuit. So the first step is to calculate the open circuit voltage across $V_{AB}$. Since no current is flowing across the Circuit $V_{AB}$ is same as $V_x$ is same as 10V. Here is a good link Thévenin's theorem or Thevenin's Equivalent – Mahendra Gunawardena Oct 26 '15 at 2:08
You start by making A-B an open circuit. This implies that the current entering or leaving node A from the load is 0 Amps. This implies that the current in the two 1 $\Omega$ resistors have the same current flowing through them.
The open circuit across A-B also implies that 0 current is flowing into or out of Node B. This means 0 current is flowing through $\frac{5}{11}\Omega$ resistor, so there is 0 voltage drop across that resistor, so $V_x$ is also 10 V.
This leaves you with 10 V at $V_x$ and $0.2V_x = 2 V$ across the voltage controlled voltage source. This means the current flowing in the loop with the two 1 $\Omega$ resistors is $\frac{2 V}{2\Omega} = 1 A$. This also means the voltage between the voltage controlled voltage source and the bottom 1 $\Omega$ resistor is $12 V$.
With this information you can calculate the voltage drop across the lower 1 $\Omega$ resistor to be $1V$, which gives you a $V_{th}$ of $11 V$.
You are right in that $V_x$ can't be 10 V. Fortunately, 10V for $V_x$ simplifies the circuit considerably, making it particularly easy to analyze.
Since $V_x$ is the same voltage as the supply on the left, both ends of the 5/11 Ω resistor are at the same voltage. That means the current thru it is zero. That means the current thru anything directly in series with is must also be zero. Therefore, the current thru the 5/11 Ω resistor, the 10 V power supply, and the 1 Ω resistor at right are all 0. The voltage across any resistor with 0 current thru it must also be 0. We therefore know that point A is at 0 V.
Taking the loop with the 2 V supply and the two 1 Ω resistors in isolation, we can easily see that 1 A must be circulating, as indicated by your curved arrow. 1 A thru a 1 Ω resistor causes a 1 V drop, so the right end of this loop must be 1 V higher than the left.
Putting this back into the rest of the circuit that is known to carry 0 current just doesn't work. According to previous logic, point A must be at 0 V, but adding the +2 V of the supply and -1 V of the resistor to the 10 V at $V_x$ yields 11 V at A, which is a contradiction.
Clearly something is wrong somewhere.
• This: "That means the current thru anything directly in series with is must also be zero." doesn't imply this: "the 1 Ω resistor at right are all 0". Why? Because you have a voltage controlled voltage voltage source and the loop there. So your second answer of 11 V is correct. – Eric Oct 26 '15 at 16:21
When calculating $V_{th}$ , $V_{AB}$ is open circuited as in the diagram. As a result there is no current flow across $\frac{5}{11} \Omega$. Thus $V_x = 10V$
References:
• But there is current in loop I. – Eric Oct 26 '15 at 16:53 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8426347970962524, "perplexity": 382.8504785139403}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347419593.76/warc/CC-MAIN-20200601180335-20200601210335-00293.warc.gz"} |
https://math.stackexchange.com/questions/2537849/is-the-borel-sigma-algebra-over-reals-a-complete-lattice | # Is the borel $\sigma$-algebra over reals a complete lattice?
I've read in some forum answer that "the Borel sigma-algebra on the real numbers $$\mathscr{B}(\mathbb{R})$$ is not a complete lattice" and I was wondering why and hope you can help.
Def. a complete lattice is a partially ordered set in which all subsets have both a supremum (join) and an infimum (meet).
Def. The Borel $$\sigma$$-algebra on the reals is the smallest $$\sigma$$-algebra that contains all the open sets
One way for the above statement to hold would be if $$[-\infty,\infty] \notin \mathscr{B}(\mathbb{R})$$ -is this the case and why?
I would have guessed that $$[-\infty,\infty] \in \mathscr{B}(\mathbb{R})$$; because $$\mathscr{B}(\mathbb{R})$$ is closed under countable union and all open and closed sets exist in it, thus, $$(0,1),[1,2]\in \mathscr{B}(\mathbb{R})\Rightarrow [-\infty,1),[1,\infty]\in \mathscr{B}(\mathbb{R}) \Rightarrow [-\infty,\infty]\in \mathscr{B}(\mathbb{R})$$.
PS: I hope the tags are correct.
Note that every singleton is a Borel set in the case of $\Bbb R$. So for the Borel sets to form a complete lattice, any collection of singletons must have a join.
• There are $\mathfrak{c}$ many Borel sets (does this depend on choice?) and $2^\mathfrak{c}$ many subsets of $\mathbb{R}$ so counting gives us non-Borel sets already. Nov 26 '17 at 12:32
• @Henno: If $\Bbb R$ is a countable union of countable sets, then every set is Borel. Nov 26 '17 at 12:54
• So this could be formulated as: Every singleton set of $\mathbb{R}$ exists in $\mathscr{B}(\mathbb{R})$. In order for $\mathscr{B}(\mathbb{R})$ to form a complete lattice, any collection of singletons must have a join. This is not true for a set containing all but one of the singletons, e.g. $\{\{r\} \mid r \in \mathbb{R}\setminus \{0\}\} \notin \mathscr{B}(\mathbb{R})$. Nov 30 '17 at 13:56 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 7, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8248457908630371, "perplexity": 166.30425417668386}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320303385.49/warc/CC-MAIN-20220121131830-20220121161830-00404.warc.gz"} |
http://mathhelpforum.com/pre-calculus/192669-simplifying-log-expression-y-print.html | # Simplifying log expression for y
• November 25th 2011, 11:28 AM
benny92000
Simplifying log expression for y
5^(y) = 2e^(y)
I proceeded to take the natural log of both sides, so yln(5) = ln2e(y) Where do I go from here?
• November 25th 2011, 11:39 AM
e^(i*pi)
Re: Simplifying log expression for y
Quote:
Originally Posted by benny92000
5^(y) = 2e^(y)
I proceeded to take the natural log of both sides, so yln(5) = ln2e(y) Where do I go from here?
Use the log addition rule to separate the RHS: $\ln(2e^y) = \ln(2) + \ln(e^y) = \ln(2) + y$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 1, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6131084561347961, "perplexity": 2318.6744858986735}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1414119646180.24/warc/CC-MAIN-20141024030046-00240-ip-10-16-133-185.ec2.internal.warc.gz"} |
http://mxnet.incubator.apache.org/versions/1.6/api/r/docs/api/mx.nd.sample.multinomial.html | # mx.nd.sample.multinomial¶
## Description¶
Concurrent sampling from multiple multinomial distributions.
data is an n dimensional array whose last dimension has length k, where k is the number of possible outcomes of each multinomial distribution. This operator will draw shape samples from each distribution. If shape is empty one sample will be drawn from each distribution.
If get_prob is true, a second array containing log likelihood of the drawn samples will also be returned. This is usually used for reinforcement learning where you can provide reward as head gradient for this array to estimate gradient.
Note that the input distribution must be normalized, i.e. data must sum to 1 along its last axis.
Example:
probs = [[0, 0.1, 0.2, 0.3, 0.4], [0.4, 0.3, 0.2, 0.1, 0]]
// Draw a single sample for each distribution
sample_multinomial(probs) = [3, 0]
// Draw a vector containing two samples for each distribution
sample_multinomial(probs, shape=(2)) = [[4, 2],
[0, 0]]
// requests log likelihood
sample_multinomial(probs, get_prob=True) = [2, 1], [0.2, 0.3]
## Arguments¶
Argument
Description
data
NDArray-or-Symbol.
Distribution probabilities. Must sum to one on the last axis.
shape
Shape(tuple), optional, default=[].
Shape to be sampled from each random distribution.
get.prob
boolean, optional, default=0.
Whether to also return the log probability of sampled result. This is usually used for differentiating through stochastic variables, e.g. in reinforcement learning.
dtype
{‘float16’, ‘float32’, ‘float64’, ‘int32’, ‘uint8’},optional, default=’int32’.
DType of the output in case this can’t be inferred.
## Value¶
out The result mx.ndarray | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6166053414344788, "perplexity": 2114.854683635545}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600401632671.79/warc/CC-MAIN-20200929060555-20200929090555-00489.warc.gz"} |
https://www.mail-archive.com/search?l=lyx-users%40lists.lyx.org&q=date:20100125&o=newest | ### How to determine where I am on a page.
I have hacked up my own class file. It does 95% of what I set out to achieve. However, I am stuck with the final bit of polish. I have an element that I don't want to appear at the bottom of a page. Therefore, I need to test to find out how far down the page I am, and if more than 75% of the page
### Re: How to determine where I am on a page.
Philip Stubbs wrote: I have an element that I don't want to appear at the bottom of a page. Therefore, I need to test to find out how far down the page I am, and if more than 75% of the page is used, insert a \newpage. One possibility:
### Re: How to determine where I am on a page.
On 01/25/2010 04:52 AM, Jürgen Spitzmüller wrote: % Conditional pagebreak \def\condbreak#1{% \vskip 0pt plus #1\pagebreak[3]\vskip 0pt plus -#1\relax} As a related question: What does \relax do, and when does one need it? rh
### Re: Change tracking
On 01/23/2010 04:59 AM, E. Kaplan wrote: It seems that inserting notes into a Lyx file while tracking changes modifies the color of some parts of the text in the pdf output to blue, misleading the reader to believe that the blue text is new insertions, while it is not. This is true of both
### Re: How to determine where I am on a page.
rgheck wrote: As a related question: What does \relax do, and when does one need it? http://en.wikibooks.org/wiki/TeX/relax Note, though, that the \condbreak macro is not my doing. I've picked it up eventually on comp.text.tex. Jürgen
### Re: How to determine where I am on a page.
On 01/25/2010 07:59 AM, Jürgen Spitzmüller wrote: rgheck wrote: As a related question: What does \relax do, and when does one need it? http://en.wikibooks.org/wiki/TeX/relax Thanks. I thought it must be something like that. rh
### Don't understand LaTeX Error
Hello, I'm working with Lyx 1.6.5 and JabRef 2.5 When I want to view the following LaTeX Source as PDF (pdflatex), I get at the end of the first LaTeX run 4 LaTeX errors: LaTeX Source: \subsubsection{Die Familien Busch vor der Hardt und Flender\label{sub:Die-Familien-Busch}% \footnote{Aus
### Re: Don't understand LaTeX Error
On 01/25/2010 10:37 AM, Matthias Schmidt wrote: Hello, I'm working with Lyx 1.6.5 and JabRef 2.5 When I want to view the following LaTeX Source as PDF (pdflatex), I get at the end of the first LaTeX run 4 LaTeX errors: I think the problem is that you have put a footnote inside a
### Re: Clear double page and start at left page
Finally managed to solve the problem using the textpos package. In your preamble, put: % absolute to use whole page, showboxes draws line around each box, useful for debugging \usepackage[absolute,showboxes]{textpos} % sets up a grid, useful for debugging \usepackage[texcoord,colorgrid]{eso-pic}
### lyx2lyx failure
I am trying to open a lyx file produced by a conversion script and Lyx (1.6.5) fails claiming lyx2lyx could not convert it. The lyx file is in lyx format 2.16 (or so it claims in its header). Launching lyx2lyx from the console gives the following error: Warning: An error ocurred in 225,
### Index of descriptions
Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or something to automate it: I need to look for all descriptions in a file and insert an index entry with the described item as text. Thanks, Manolo
### photographs: what format to use for b/w printing via lyx?
Does anyone have any useful input on what photo format gives the best quality results on b/w printing via lyx? Are there any optimal values, or things to worry about? TIA Richard
### Re: Don't understand LaTeX Error
yes, I didn't think about the table of contents, ok. But I would like to understand, what is happening there: I get the LaTeX error only with \citet{GieslerG1990} but not with \cite{GieslerG1990}. Why doesn't Lyx accept this one citation style but the other one is ok? am Montag, 25. Januar 2010
### RE: photographs: what format to use for b/w printing via lyx?
Hi Richard, What kinds of photos are they? For example, are they screenshots that you've converted to black and white? Or are they text on a white background? Or are they grayscale images or are they true black and white (two-tone images)? Are there any pertinent details that you wish to
### Re: Document with PDFs
Is this not the right list for this kind of errors? Should I check bugzilla? Can someone send it to the developer list? My wife told me that today she closed all the footnotes and was able to compile the document. I haven't been able to verify this, but I'll try later tonight. Best regards.
### Re: Index of descriptions
On 01/25/2010 11:56 AM, Manolo Martínez wrote: Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or something to automate it: I need to look for all descriptions in a file and insert an index entry with the described item as text.
### RE: photographs: what format to use for b/w printing via lyx?
Thanks for that encouraging reply, Rob. Can I ask a quick supplementary? I have colour jpgs, not particularly high res but neither are they poor. And I'm making a pdf for submission to a printer, to be printed in b/w. The jpgs are atthe moment much bigger than I need: I'll have to scale them to
### Re: Index of descriptions
But that does not save me from going description by description adding the glossary entry manually, does it? Manolo rgheck escribió: On 01/25/2010 11:56 AM, Manolo Martínez wrote: Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or
### Re: Index of descriptions
On 01/25/2010 02:37 PM, Manolo Martínez wrote: But that does not save me from going description by description adding the glossary entry manually, does it? You could redefine the description environment in such a way that it handled this for you, I think. rh Manolo rgheck escribió: On
### RE: photographs: what format to use for b/w printing via lyx?
Hi Richard, Can I ask a quick supplementary? Of course. The jpgs are at the moment much bigger than I need: I'll have to scale them to about 40%. Should I process the jpgs into monochrome tiffs? Or would the conversion cost me definition? By all means, process the files. If possible, do
### Instead of A B .. in Appendix Appendix A Appendix B
Hi I would like to have, instead of the standard numbering in the Appendix (A, B, ...) a numbering like Appendix A: HERE COMES MY TITLE Appendix A: HERE COMES MY SECOND TITLE . . . How can I achieve this? Thanks, Rainer -- NEW GERMAN FAX NUMBER!!! Rainer M. Krug, PhD (Conservation
### Re: Instead of A B .. in Appendix Appendix A Appendix B
On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: Hi I would like to have, instead of the standard numbering in the Appendix (A, B, ...) a numbering like Appendix A: HERE COMES MY TITLE Appendix A: HERE COMES MY SECOND TITLE . . . How can I achieve this? Thanks, Rainer
### Genealogy symbols
Hello, I need genealogy symbols in a lyx-document. I installed the genealogy package with the MiKTeX package manager, reconfigured lyx, started lyx again - but I don't find the symbols (insert/special character/symbols). Please, how can I use the genealogy symbols in my document? -- Mit
### RE: photographs: what format to use for b/w printing via lyx?
Thanks, Rob. That was very clear and helpful! Richard On Mon, 2010-01-25 at 13:12 -0700, Rob Oakes wrote: Hi Richard, Can I ask a quick supplementary? Of course. The jpgs are at the moment much bigger than I need: I'll have to scale them to about 40%. Should I process the jpgs
### Re: Instead of A B .. in Appendix Appendix A Appendix B
On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt [email protected]: On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: Hi I would like to have, instead of the standard numbering in the Appendix (A, B, ...) a numbering like Appendix A: HERE COMES MY TITLE Appendix A:
### Re: Instead of A B .. in Appendix Appendix A Appendix B
On Monday 25 January 2010 16:53:30 Rainer M Krug wrote: On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt [email protected]: On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: Hi I would like to have, instead of the standard numbering in the Appendix (A, B, ...) a
### Re: Instead of A B .. in Appendix Appendix A Appendix B
On Tue, Jan 26, 2010 at 12:22 AM, Steve Litt [email protected]: On Monday 25 January 2010 16:53:30 Rainer M Krug wrote: On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt [email protected]: On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: Hi I would
### Re: Index of descriptions
OK, thanks, I'll try that. M rgheck escribió: On 01/25/2010 02:37 PM, Manolo Martínez wrote: But that does not save me from going description by description adding the glossary entry manually, does it? You could redefine the description environment in such a way that it handled this for
### How to determine where I am on a page.
I have hacked up my own class file. It does 95% of what I set out to achieve. However, I am stuck with the final bit of polish. I have an element that I don't want to appear at the bottom of a page. Therefore, I need to test to find out how far down the page I am, and if more than 75% of the page
### Re: How to determine where I am on a page.
Philip Stubbs wrote: I have an element that I don't want to appear at the bottom of a page. Therefore, I need to test to find out how far down the page I am, and if more than 75% of the page is used, insert a \newpage. One possibility:
### Re: How to determine where I am on a page.
On 01/25/2010 04:52 AM, Jürgen Spitzmüller wrote: % Conditional pagebreak \def\condbreak#1{% \vskip 0pt plus #1\pagebreak[3]\vskip 0pt plus -#1\relax} As a related question: What does \relax do, and when does one need it? rh
### Re: Change tracking
On 01/23/2010 04:59 AM, E. Kaplan wrote: It seems that inserting notes into a Lyx file while tracking changes modifies the color of some parts of the text in the pdf output to blue, misleading the reader to believe that the blue text is new insertions, while it is not. This is true of both
### Re: How to determine where I am on a page.
rgheck wrote: As a related question: What does \relax do, and when does one need it? http://en.wikibooks.org/wiki/TeX/relax Note, though, that the \condbreak macro is not my doing. I've picked it up eventually on comp.text.tex. Jürgen
### Re: How to determine where I am on a page.
On 01/25/2010 07:59 AM, Jürgen Spitzmüller wrote: rgheck wrote: As a related question: What does \relax do, and when does one need it? http://en.wikibooks.org/wiki/TeX/relax Thanks. I thought it must be something like that. rh
### Don't understand LaTeX Error
Hello, I'm working with Lyx 1.6.5 and JabRef 2.5 When I want to view the following LaTeX Source as PDF (pdflatex), I get at the end of the first LaTeX run 4 LaTeX errors: LaTeX Source: \subsubsection{Die Familien Busch vor der Hardt und Flender\label{sub:Die-Familien-Busch}% \footnote{Aus
### Re: Don't understand LaTeX Error
On 01/25/2010 10:37 AM, Matthias Schmidt wrote: Hello, I'm working with Lyx 1.6.5 and JabRef 2.5 When I want to view the following LaTeX Source as PDF (pdflatex), I get at the end of the first LaTeX run 4 LaTeX errors: I think the problem is that you have put a footnote inside a
### Re: Clear double page and start at left page
Finally managed to solve the problem using the textpos package. In your preamble, put: % absolute to use whole page, showboxes draws line around each box, useful for debugging \usepackage[absolute,showboxes]{textpos} % sets up a grid, useful for debugging \usepackage[texcoord,colorgrid]{eso-pic}
### lyx2lyx failure
I am trying to open a lyx file produced by a conversion script and Lyx (1.6.5) fails claiming lyx2lyx could not convert it. The lyx file is in lyx format 2.16 (or so it claims in its header). Launching lyx2lyx from the console gives the following error: Warning: An error ocurred in 225,
### Index of descriptions
Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or something to automate it: I need to look for all descriptions in a file and insert an index entry with the described item as text. Thanks, Manolo
### photographs: what format to use for b/w printing via lyx?
Does anyone have any useful input on what photo format gives the best quality results on b/w printing via lyx? Are there any optimal values, or things to worry about? TIA Richard
### Re: Don't understand LaTeX Error
yes, I didn't think about the table of contents, ok. But I would like to understand, what is happening there: I get the LaTeX error only with \citet{GieslerG1990} but not with \cite{GieslerG1990}. Why doesn't Lyx accept this one citation style but the other one is ok? am Montag, 25. Januar 2010
### RE: photographs: what format to use for b/w printing via lyx?
Hi Richard, What kinds of photos are they? For example, are they screenshots that you've converted to black and white? Or are they text on a white background? Or are they grayscale images or are they true black and white (two-tone images)? Are there any pertinent details that you wish to
### Re: Document with PDFs
Is this not the right list for this kind of errors? Should I check bugzilla? Can someone send it to the developer list? My wife told me that today she closed all the footnotes and was able to compile the document. I haven't been able to verify this, but I'll try later tonight. Best regards.
### Re: Index of descriptions
On 01/25/2010 11:56 AM, Manolo Martínez wrote: Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or something to automate it: I need to look for all descriptions in a file and insert an index entry with the described item as text.
### RE: photographs: what format to use for b/w printing via lyx?
Thanks for that encouraging reply, Rob. Can I ask a quick supplementary? I have colour jpgs, not particularly high res but neither are they poor. And I'm making a pdf for submission to a printer, to be printed in b/w. The jpgs are atthe moment much bigger than I need: I'll have to scale them to
### Re: Index of descriptions
But that does not save me from going description by description adding the glossary entry manually, does it? Manolo rgheck escribió: On 01/25/2010 11:56 AM, Manolo Martínez wrote: Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or
### Re: Index of descriptions
On 01/25/2010 02:37 PM, Manolo Martínez wrote: But that does not save me from going description by description adding the glossary entry manually, does it? You could redefine the description environment in such a way that it handled this for you, I think. rh Manolo rgheck escribió: On
### RE: photographs: what format to use for b/w printing via lyx?
Hi Richard, Can I ask a quick supplementary? Of course. The jpgs are at the moment much bigger than I need: I'll have to scale them to about 40%. Should I process the jpgs into monochrome tiffs? Or would the conversion cost me definition? By all means, process the files. If possible, do
### Instead of A B .. in Appendix Appendix A Appendix B
Hi I would like to have, instead of the standard numbering in the Appendix (A, B, ...) a numbering like Appendix A: HERE COMES MY TITLE Appendix A: HERE COMES MY SECOND TITLE . . . How can I achieve this? Thanks, Rainer -- NEW GERMAN FAX NUMBER!!! Rainer M. Krug, PhD (Conservation
### Re: Instead of A B .. in Appendix Appendix A Appendix B
On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: Hi I would like to have, instead of the standard numbering in the Appendix (A, B, ...) a numbering like Appendix A: HERE COMES MY TITLE Appendix A: HERE COMES MY SECOND TITLE . . . How can I achieve this? Thanks, Rainer
### Genealogy symbols
Hello, I need genealogy symbols in a lyx-document. I installed the genealogy package with the MiKTeX package manager, reconfigured lyx, started lyx again - but I don't find the symbols (insert/special character/symbols). Please, how can I use the genealogy symbols in my document? -- Mit
### RE: photographs: what format to use for b/w printing via lyx?
Thanks, Rob. That was very clear and helpful! Richard On Mon, 2010-01-25 at 13:12 -0700, Rob Oakes wrote: Hi Richard, Can I ask a quick supplementary? Of course. The jpgs are at the moment much bigger than I need: I'll have to scale them to about 40%. Should I process the jpgs
### Re: Instead of A B .. in Appendix Appendix A Appendix B
On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt [email protected]: On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: Hi I would like to have, instead of the standard numbering in the Appendix (A, B, ...) a numbering like Appendix A: HERE COMES MY TITLE Appendix A:
### Re: Instead of A B .. in Appendix Appendix A Appendix B
On Monday 25 January 2010 16:53:30 Rainer M Krug wrote: On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt [email protected]: On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: Hi I would like to have, instead of the standard numbering in the Appendix (A, B, ...) a
### Re: Instead of A B .. in Appendix Appendix A Appendix B
On Tue, Jan 26, 2010 at 12:22 AM, Steve Litt [email protected]: On Monday 25 January 2010 16:53:30 Rainer M Krug wrote: On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt [email protected]: On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: Hi I would
### Re: Index of descriptions
OK, thanks, I'll try that. M rgheck escribió: On 01/25/2010 02:37 PM, Manolo Martínez wrote: But that does not save me from going description by description adding the glossary entry manually, does it? You could redefine the description environment in such a way that it handled this for
### How to determine where I am on a page.
I have hacked up my own class file. It does 95% of what I set out to achieve. However, I am stuck with the final bit of polish. I have an element that I don't want to appear at the bottom of a page. Therefore, I need to test to find out how far down the page I am, and if more than 75% of the page
### Re: How to determine where I am on a page.
Philip Stubbs wrote: > I have an element that I don't want to appear at the bottom of a page. > Therefore, I need to test to find out how far down the page I am, and > if more than 75% of the page is used, insert a \newpage. One possibility:
### Re: How to determine where I am on a page.
On 01/25/2010 04:52 AM, Jürgen Spitzmüller wrote: % Conditional pagebreak \def\condbreak#1{% \vskip 0pt plus #1\pagebreak[3]\vskip 0pt plus -#1\relax} As a related question: What does \relax do, and when does one need it? rh
### Re: Change tracking
On 01/23/2010 04:59 AM, E. Kaplan wrote: It seems that inserting notes into a Lyx file while tracking changes modifies the color of some parts of the text in the pdf output to blue, misleading the reader to believe that the blue text is new insertions, while it is not. This is true of both
### Re: How to determine where I am on a page.
rgheck wrote: > As a related question: What does \relax do, and when does one need it? http://en.wikibooks.org/wiki/TeX/relax Note, though, that the \condbreak macro is not my doing. I've picked it up eventually on comp.text.tex. Jürgen
### Re: How to determine where I am on a page.
On 01/25/2010 07:59 AM, Jürgen Spitzmüller wrote: rgheck wrote: As a related question: What does \relax do, and when does one need it? http://en.wikibooks.org/wiki/TeX/relax Thanks. I thought it must be something like that. rh
### Don't understand LaTeX Error
Hello, I'm working with Lyx 1.6.5 and JabRef 2.5 When I want to view the following LaTeX Source as PDF (pdflatex), I get at the end of the first LaTeX run 4 LaTeX errors: LaTeX Source: \subsubsection{Die Familien Busch vor der Hardt und Flender\label{sub:Die-Familien-Busch}% \footnote{Aus
### Re: Don't understand LaTeX Error
On 01/25/2010 10:37 AM, Matthias Schmidt wrote: Hello, I'm working with Lyx 1.6.5 and JabRef 2.5 When I want to view the following LaTeX Source as PDF (pdflatex), I get at the end of the first LaTeX run 4 LaTeX errors: I think the problem is that you have put a footnote inside a
### Re: Clear double page and start at left page
Finally managed to solve the problem using the textpos package. In your preamble, put: % absolute to use whole page, showboxes draws line around each box, useful for debugging \usepackage[absolute,showboxes]{textpos} % sets up a grid, useful for debugging \usepackage[texcoord,colorgrid]{eso-pic}
### lyx2lyx failure
I am trying to open a lyx file produced by a conversion script and Lyx (1.6.5) fails claiming lyx2lyx could not convert it. The lyx file is in lyx format 2.16 (or so it claims in its header). Launching lyx2lyx from the console gives the following error: Warning: An error ocurred in 225,
### Index of descriptions
Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or something to automate it: I need to look for all descriptions in a file and insert an index entry with the described item as text. Thanks, Manolo
### photographs: what format to use for b/w printing via lyx?
Does anyone have any useful input on what photo format gives the best quality results on b/w printing via lyx? Are there any optimal values, or things to worry about? TIA Richard
### Re: Don't understand LaTeX Error
yes, I didn't think about the table of contents, ok. But I would like to understand, what is happening there: I get the LaTeX error only with "\citet{GieslerG1990}" but not with "\cite{GieslerG1990}". Why doesn't Lyx accept this one citation style but the other one is ok? am Montag, 25. Januar
### RE: photographs: what format to use for b/w printing via lyx?
Hi Richard, What kinds of photos are they? For example, are they screenshots that you've converted to black and white? Or are they text on a white background? Or are they grayscale images or are they true black and white (two-tone images)? Are there any pertinent details that you wish to
### Re: Document with PDFs
Is this not the right list for this kind of errors? Should I check bugzilla? Can someone send it to the developer list? My wife told me that today she closed all the footnotes and was able to compile the document. I haven't been able to verify this, but I'll try later tonight. Best regards.
### Re: Index of descriptions
On 01/25/2010 11:56 AM, Manolo Martínez wrote: Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or something to automate it: I need to look for all descriptions in a file and insert an index entry with the described item as text.
### RE: photographs: what format to use for b/w printing via lyx?
Thanks for that encouraging reply, Rob. Can I ask a quick supplementary? I have colour jpgs, not particularly high res but neither are they poor. And I'm making a pdf for submission to a printer, to be printed in b/w. The jpgs are atthe moment much bigger than I need: I'll have to scale them to
### Re: Index of descriptions
But that does not save me from going description by description adding the glossary entry manually, does it? Manolo rgheck escribió: On 01/25/2010 11:56 AM, Manolo Martínez wrote: Dear list, I was wondering if any of you has had to do this before, and has maybe programmed a script or
### Re: Index of descriptions
On 01/25/2010 02:37 PM, Manolo Martínez wrote: But that does not save me from going description by description adding the glossary entry manually, does it? You could redefine the description environment in such a way that it handled this for you, I think. rh Manolo rgheck escribió: On
### RE: photographs: what format to use for b/w printing via lyx?
Hi Richard, << Can I ask a quick supplementary? >> Of course. << The jpgs are at the moment much bigger than I need: I'll have to scale them to about 40%. Should I process the jpgs into monochrome tiffs? Or would the conversion cost me definition? >> By all means, process the files. If
### Instead of "A" "B" .. in Appendix "Appendix A" "Appendix B"
Hi I would like to have, instead of the standard numbering in the Appendix ("A", "B", ...) a numbering like Appendix A: HERE COMES MY TITLE Appendix A: HERE COMES MY SECOND TITLE . . . How can I achieve this? Thanks, Rainer -- NEW GERMAN FAX NUMBER!!! Rainer M. Krug, PhD (Conservation
### Re: Instead of "A" "B" .. in Appendix "Appendix A" "Appendix B"
On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: > Hi > > I would like to have, instead of the standard numbering in the Appendix > ("A", "B", ...) a numbering like > > Appendix A: HERE COMES MY TITLE > Appendix A: HERE COMES MY SECOND TITLE > . > . > . > > How can I achieve this? > >
### Genealogy symbols
Hello, I need genealogy symbols in a lyx-document. I installed the genealogy package with the MiKTeX package manager, reconfigured lyx, started lyx again - but I don't find the symbols (insert/special character/symbols). Please, how can I use the genealogy symbols in my document? -- Mit
### RE: photographs: what format to use for b/w printing via lyx?
Thanks, Rob. That was very clear and helpful! Richard On Mon, 2010-01-25 at 13:12 -0700, Rob Oakes wrote: > Hi Richard, > > << Can I ask a quick supplementary? >> > > Of course. > > << The jpgs are at the moment much bigger than I need: I'll have to scale > them to about 40%. Should I
### Re: Instead of "A" "B" .. in Appendix "Appendix A" "Appendix B"
On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt wrote: > On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: > > Hi > > > > I would like to have, instead of the standard numbering in the Appendix > > ("A", "B", ...) a numbering like > > > > Appendix A: HERE COMES MY
### Re: Instead of "A" "B" .. in Appendix "Appendix A" "Appendix B"
On Monday 25 January 2010 16:53:30 Rainer M Krug wrote: > On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt wrote: > > On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: > > > Hi > > > > > > I would like to have, instead of the standard numbering in the Appendix > > >
### Re: Instead of "A" "B" .. in Appendix "Appendix A" "Appendix B"
On Tue, Jan 26, 2010 at 12:22 AM, Steve Litt wrote: > On Monday 25 January 2010 16:53:30 Rainer M Krug wrote: > > On Mon, Jan 25, 2010 at 11:12 PM, Steve Litt > wrote: > > > On Monday 25 January 2010 15:24:26 Rainer M Krug wrote: > > > > Hi >
### Re: Index of descriptions
OK, thanks, I'll try that. M rgheck escribió: On 01/25/2010 02:37 PM, Manolo Martínez wrote: But that does not save me from going description by description adding the glossary entry manually, does it? You could redefine the description environment in such a way that it handled this for | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8430993556976318, "perplexity": 2802.0049184879645}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623488539480.67/warc/CC-MAIN-20210623134306-20210623164306-00465.warc.gz"} |
http://prof.clontz.org/classes/2017/06/ma227/standards/s08/ | # MA 227 Standard S08
Transformations of Variables
At the end of the course, each student should be able to…
• S08: TransVar. Compute and apply a transformation of variables.
## S08: Transformations of Variables
• A transformation of variables is a function $$\vect T(u,v)=\<x,y\>$$ that converts vectors $$\<u,v\>$$ in the $$uv$$ plane into vectors $$\<x,y\>$$ in the $$xy$$ plane.
• A transformation is called affine if it preserves parallelograms.
• All affine transformations are of the form $$\vect T(u,v)=\<a_1u+b_1v+c_1,a_2u+b_2v+c_2\>$$.
• To find a transformation from the unit square in the $$uv$$ plane to a parallelogram, the values of $$a,b,c$$ may be calculated by setting each of $$\vect T(0,0),\vect T(1,0), \vect T(1,1), \vect T(0,1)$$ to each of its corners.
• To find a transformation from the unit triangle in the $$uv$$ plane to a parallelogram, the values of $$a,b,c$$ may be calculated by setting each of $$\vect T(0,0),\vect T(1,0), \vect T(1,1)$$ to each of its corners.
• Affine transformations scale areas by a factor of $$\detTwo{a_1}{b_1}{a_2}{b_2}$$ (where this value is negative when the transformation reflects orientation). This generalizes to the Jacobian $$\frac{\partial\vect T}{\partial\<u,v\>}=\detTwo {\frac{\partial x}{\partial u}}{\frac{\partial x}{\partial v}} {\frac{\partial y}{\partial u}}{\frac{\partial y}{\partial v}}$$ for more arbitrary transformations.
• It follows that if the transformation $$\vect T(u,v)$$ transforms the region $$G$$ in the $$uv$$ plane into the region $$R$$ in the $$xy$$ plane, then $$\iint_R f(x,y)\,dA=\iint_G f(\vect T(u,v))|\frac{\partial\vect T}{\partial\<u,v\>}|\,dA$$.
• Similarly for 3D transformations $$\vect T(u,v,w)=\<x,y,z\>$$ sending $$H$$ to $$D$$, it may be shown that $$\iiint_D f(x,y,z)\,dV=\iiint_H f(\vect T(u,v,w))|\frac{\partial\vect T}{\partial\<u,v,w\>}|\,dV$$ where $$\frac{\partial\vect T}{\partial\<u,v,w\>}=\detThree {\frac{\partial x}{\partial u}}{\frac{\partial x}{\partial v}} {\frac{\partial x}{\partial w}} {\frac{\partial y}{\partial u}}{\frac{\partial y}{\partial v}} {\frac{\partial y}{\partial w}} {\frac{\partial z}{\partial u}}{\frac{\partial z}{\partial v}} {\frac{\partial z}{\partial w}}$$.
### Textbook References
• University Calculus: Early Transcendentals (3rd Ed)
• 14.8
### Practice Exercises
Let the unit square have vertices $$\<0,0\>$$, $$\<1,0\>$$, $$\<1,1\>$$, and $$\<0,1\>$$. Let the unit triangle have vertices $$\<0,0\>$$, $$\<1,0\>$$, and $$\<1,1\>$$.
1. Find a transformation from either the unit square or unit triangle in the $$uv$$ plane into the given region $$R$$ in the $$xy$$ plane.
• $$R$$: the parallelogram bounded by $$y=3x+1$$, $$y=3x-3$$, $$y=x-3$$ $$y=x+1$$
• $$R$$: the triangle bounded by $$y=x$$, $$y=2x$$, $$y=6-x$$
• $$R$$: the square with vertices $$\<2,1\>$$, $$\<-2,3\>$$, $$\<0,7\>$$, $$\<4,5\>$$
• $$R$$: the triangle with vertices $$\<0,-2\>$$ $$\<-1,1\>$$, $$\<1,3\>$$
2. Evaluate the double integral with variables $$x,y$$ using the given transformation from the $$uv$$ plane.
• $$\iint_R (2y-4x)\,dA$$, $$\vect{T}(u,v)=\<u+v,2u-v+3\>$$ from the unit square into the parallelogram $$R$$ with vertices $$\<0,3\>$$, $$\<1,5\>$$, $$\<2,4\>$$, $$\<1,2\>$$.
• $$\iint_R (x+y)(x-y-2)\,dA$$, $$\vect{T}(u,v)=\<4-u-v,v-u+2\>$$ from unit triangle into the triangle $$R$$ with vertices $$\<4,2\>$$, $$\<3,1\>$$, $$\<2,2\>$$.
• $$\iint_R (x+y)e^{x^2-y^2}\,dA$$, $$\vect{T}(u,v)=\<u+2v,u-2v\>$$ from unit square into the rectangle $$R$$ bounded by $$y=x$$, $$y=x-4$$, $$y=-x$$, $$y=2-x$$.
• $$\iint_R \cos(e^x)\,dA$$, $$\vect{T}(u,v)=\<\ln (u+v+1),v\>$$ from unit triangle into the region $$R$$ bounded by $$y=0$$, $$y=e^x-2$$, $$y=\frac{e^x-1}{2}$$.
### Solutions
1. Find the transformation (solutions are not unique):
• $$\vect T(u,v)=\<2u+2v-2,2u+6v-5\>$$
• $$\vect T(u,v)=\<3u-v,3u+v\>$$
• $$\vect T(u,v)=\<4u+2v-2,-2u+4v+3\>$$
• $$\vect T(u,v)=\<u+v-1,-3u+5v+1\>$$
2. Evaluate the integral:
• $$9$$
• $$\frac{3}{2}$$
• $$\frac{1}{8}(e^8-9)$$
• $$-\frac{1}{2}\cos(3)+\cos(2)-\frac{1}{2}\cos(1)$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9883013367652893, "perplexity": 338.13172973783577}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891813622.87/warc/CC-MAIN-20180221123439-20180221143439-00679.warc.gz"} |
https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=142&t=45116 | ## change in cell potential
$E_{cell} = E_{cell}^{\circ}-\frac{RT}{nF}\ln Q$
005199302
Posts: 108
Joined: Fri Sep 28, 2018 12:15 am
### change in cell potential
Is the change in cell potential E-E(standard) or E(standard)-E
Noah Cook 3O
Posts: 31
Joined: Fri Sep 28, 2018 12:20 am
### Re: change in cell potential
E-E(standard), as it is derived from the nernst equation which has E = E(standard) - (stuff).
Return to “Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)”
### Who is online
Users browsing this forum: No registered users and 1 guest | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 1, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2992745041847229, "perplexity": 16714.921348164866}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141197278.54/warc/CC-MAIN-20201129063812-20201129093812-00629.warc.gz"} |
https://planetmath.org/SolutionsOf1xx2x3y2 | # solutions of $1+x+x^{2}+x^{3}=y^{2}$
This article shows that the only solutions in integers to the equation
$1+x+x^{2}+x^{3}=y^{2}$
are the obvious trivial solutions $x=0,\pm 1$ together with $x=7,y=20$. This result was known to Fermat.
First, note that the equation is $(1+x)(1+x^{2})=y^{2}$, so we have immediately that $x\geq-1$. So, noting the solutions for $x=0,\pm 1$, assume in what follows that $x>1$.
Let $d=\gcd(1+x,1+x^{2})$. Then $x\equiv-1\pmod{d}$, so that $1+x^{2}\equiv 2\pmod{d}$. But $d\mid 1+x^{2}$ so that $2\equiv 0\pmod{d}$ and $d$ is either $1$ or $2$. If $d=1$, so that $1+x$ and $1+x^{2}$ are coprime, then $1+x$ and $1+x^{2}$ must both be squares. But $1+x^{2}$ is not a square for $x>1$. Thus the $\gcd$ of $1+x$ and $1+x^{2}$ is $2$, so each must be twice a square, say
$\displaystyle 1+x=2r^{2}$ $\displaystyle 1+x^{2}=2s^{2}$
and then
$(r^{2})^{2}+(r^{2}-1)^{2}=\left(\frac{1+x}{2}\right)^{2}+\left(\frac{-1+x}{2}% \right)^{2}=\frac{1+x^{2}}{2}=s^{2}$
so that $r^{2},r^{2}-1,s$ form a primitive Pythagorean triple (note that $r>1$ since $x>1$).
Recall that if $(a,b,c)$ is a primitive Pythagorean triple, then precisely one of $a$ and $b$ is even, and we can choose coprime integers $p,q$ such that $a=p^{2}-q^{2},b=2pq,c=p^{2}+q^{2}$ or $a=2pq,b=p^{2}-q^{2},c=p^{2}+q^{2}$ depending on the parity of $a$.
Suppose first that $r$ is odd. Then
$\displaystyle r^{2}=p^{2}-q^{2}$ $\displaystyle r^{2}-1=2pq$ $\displaystyle s=p^{2}+q^{2}$
Then $1=r^{2}-(r^{2}-1)=(p-q)^{2}-2q^{2}$. Now, note that $p-q$ must be a square, say $p-q=t^{2}$, since $\gcd(p-q,p+q)=1$ and $(p-q)(p+q)$ is a square. Then
$t^{4}=(p-q)^{2}=2q^{2}+1=(q^{2}+1)^{2}-q^{4}$
so that
$t^{4}+q^{4}=(q^{2}+1)^{2}$
But we know that the sum of two fourth powers can be a square (http://planetmath.org/ExampleOfFermatsLastTheorem) only for the trivial case where all are zero. So $r$ cannot be odd.
So suppose that $r$ is even. Then
$\displaystyle r^{2}=2pq$ $\displaystyle r^{2}-1=p^{2}-q^{2}$ $\displaystyle s=p^{2}+q^{2}$
From the second of these formulas, we see that $p$ must be even (consider both sides $\pmod{4}$), say $p=2t^{2}$. Now,
$\displaystyle(p+q-1)(p+q+1)=(p+q)^{2}-1=p^{2}+2pq+q^{2}-1=\\ \displaystyle p^{2}+2pq+q^{2}-(r^{2}-(r^{2}-1))=p^{2}+2pq+q^{2}-2pq+p^{2}-q^{2% }=2p^{2}=8t^{4}$
Since $p$ and $q$ have opposite parity, $p+q\pm 1$ are even, so that
$2t^{4}=\frac{p+q-1}{2}\cdot\left(\frac{p+q-1}{2}+1\right)=u(u+1)$
Thus one of $u,u+1$ is a fourth power and the other is twice a fourth power, say $b^{4}$ and $2c^{4}$.
Now,
$\displaystyle u=b^{4}\Rightarrow u+1=2c^{4}\Rightarrow b^{4}-2c^{4}=-1$ $\displaystyle u=2c^{4}\Rightarrow u+1=b^{4}\Rightarrow b^{4}-2c^{4}=1$
so that $b^{4}-2c^{4}=\pm 1$.
If $b^{4}-2c^{4}=1$, then
$((c^{2})^{2}+1)^{2}=(c^{2})^{4}+b^{4}$
and again we have a square being the sum of two fourth powers. So this case is impossible.
If $b^{4}-2c^{4}=-1$, write $e=c^{2}$, then $(e^{2}-1)^{2}=e^{4}-b^{4}$. It follows (see here (http://planetmath.org/X4Y4z2HasNoSolutionsInPositiveIntegers)) that either $b=0$ or $e^{2}-1=0$. If $b=0$, we get the impossibility $e^{4}-2e^{2}+1=e^{4}$, while if $(e^{2}-1)^{2}=0$, then $e^{4}=b^{4},e=\pm 1$ and so $b=\pm 1$. Then $\displaystyle\frac{p+q-1}{2}=b^{4}=1$, so that $p+q=3$. Thus $r^{2}=4$, so $r=2$ and, finally, $1+x=2r^{2}=8$, so that $x=7$.
Thus, the only nontrivial solution to the equation given is
$1+7+49+343=400$
Title solutions of $1+x+x^{2}+x^{3}=y^{2}$ SolutionsOf1xx2x3y2 2013-03-22 17:05:09 2013-03-22 17:05:09 rm50 (10146) rm50 (10146) 10 rm50 (10146) Theorem msc 11F80 msc 14H52 msc 11D41 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 90, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.998707115650177, "perplexity": 84.49028968761993}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610704835583.91/warc/CC-MAIN-20210128005448-20210128035448-00637.warc.gz"} |
https://indico.eli-np.ro/event/59/?print=1 | Seminars
# Laser driven ion acceleration and limiting factors
## by Domenico Doria (ELI-NP)
Europe/Bucharest
Big Meeting Room
#### Big Meeting Room
Description
Laser-driven ion acceleration is an area receiving increasing interest in
fundamental research due to the continuous progress in high power laser
and in targetry technology, giving new insights into the acceleration
mechanisms and expanding the possibilities of application to
interdisciplinary fields. Research in this area is also motivated by
applicative prospects in fields ranging from Highenergy-density physics to
biology and medicine, neutron production and nuclear physics. Until
recently, most experimental research has been interpreted in terms of the
Target Normal Sheath Acceleration (TNSA) mechanism, where ions are
accelerated by space charge fields generated at the rear surface of the
target by relativistic electrons; while the Radiation Pressure
Acceleration (RPA) mechanism remains still not adequately explored. This
talk will give a light overview both on the acceleration mechanisms and on
the properties of the laseraccelerated ion beams. Most of the talk will
focus on the theoretical and experimental issues related to
laser-acceleration. Finally, the potentiality of the 10PW ELI-NP laser in
accelerating ions will be briefly examined. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7104717493057251, "perplexity": 8083.861772749158}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439735810.18/warc/CC-MAIN-20200803111838-20200803141838-00527.warc.gz"} |
https://rupress.org/jcb/article-standard/111/1/79/13902/Anchorage-of-secretion-competent-dense-granules-on | The ultrastructural changes in electropermeabilized bovine platelets that accompany the Ca2(+)-induced secretion of serotonin were investigated in ultra-thin sections of chemically fixed cells. Such preparations permitted us to study both the localization of and the structures associated with serotonin-containing dense granules. Localization of dense granules within cells was examined by measuring the shortest distances between the granular membranes and the plasma membrane. About 40% of total granules were located close to the plasma membrane at an average distance of 10.8 +/- 1.6 nm. 71% of the total number of granules were localized at a similar average distance of 12.5 +/- 2.7 nm in intact platelets. The percentage of granules apposed to the plasma membrane corresponded closely to the percentage of total serotonin that was maximally secreted after stimulation of the permeabilized (38 +/- 4.9%) and the intact platelets (72 +/- 3.6%). Furthermore, the percentage of granules anchored to the membrane, but not of those in other regions of permeabilized cells, decreased markedly when cells were stimulated for 30 s by extracellularly added Ca2+. The decrease in the numbers of granules in the vicinity of the plasma membrane corresponded to approximately 22% of the total number of dense granules that were used for measurements of the distances between the two membranes and corresponded roughly to the overall decrease (15%) in the average number of the granules per cell. Most dense granules were found to be associated with meshwork structures of microfilaments. Upon secretory stimulation, nonfilamentous, amorphous structures found between the plasma membrane and the apposed granules formed a bridge-like structure that connected both membranes without any obvious accompanying changes in the microfilament structures. These results suggest that the dense granules that are susceptible to secretory stimulation are anchored to the plasma membrane before stimulation, and that the formation of the bridge-like structure may participate in the Ca2(+)-regulated exocytosis.
This content is only available as a PDF. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9144551753997803, "perplexity": 2958.2119953226984}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764501066.53/warc/CC-MAIN-20230209014102-20230209044102-00804.warc.gz"} |
https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=148&t=29178&p=90049 | ## 15.37C
$\frac{d[R]}{dt}=-k[R]; \ln [R]=-kt + \ln [R]_{0}; t_{\frac{1}{2}}=\frac{0.693}{k}$
Wilson Yeh 1L
Posts: 42
Joined: Fri Sep 29, 2017 7:06 am
### 15.37C
Sulfuryl chloride, SO2Cl2, decomposes by first-order kinetics, and k = 2.81 x 10-3 min-1 at a certain temperature. (a) Determine the half-life for the reaction. (b) Determine the time needed for the concentration of SO2Cl2 to decrease to 10% of its initial concentration. (c) If 14.0 g of SO2Cl2 is sealed in a 2500.-L reaction vessel and heated to the specifi ed temperature, what mass will remain after 1.5 h?
For part C, is the 2500.-L irrelevant? I managed to solve for the final answer without ever taking the volume into account. Am I doing something wrong?
Janine Chan 2K
Posts: 71
Joined: Fri Sep 29, 2017 7:04 am
### Re: 15.37C
Nope you're good, if you divide both the initial and final mass by liters to find the concentrations of each, the liters will cancel out when you plug into [A]t=[A]0e-ktanyway.
Sue Xu 2K
Posts: 58
Joined: Fri Sep 29, 2017 7:06 am
### Re: 15.37C
It is possible to solve the question without the volume, but you can still calculate the concentration with the mass and the volume first and then calculate the final mass.
Anna Okabe
Posts: 30
Joined: Fri Sep 29, 2017 7:06 am
### Re: 15.37C
I think it would be safer to use the volume and use the molarity every time, so that you can avoid making mistakes in the future.
Emma Miltenberger 2I
Posts: 51
Joined: Thu Jul 27, 2017 3:00 am
### Re: 15.37C
In this case, the volume cancels out. However, it is good practice to use the volume to solve for molarity and use molarity in the equation to ensure you do not make an arithmetic mistake on a test.
Michelle Lu 1F
Posts: 50
Joined: Thu Jul 27, 2017 3:01 am
Been upvoted: 1 time
### Re: 15.37C
In this particular situation, the volumes end up cancelling out, so if you were able to recognize this was going to occur, then you could have left it out of the picture. However, common safe practice involves solving for the concentration using the mass given and the volume 2500. L, and this could lead to less errors. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 1, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9013078808784485, "perplexity": 1802.3237546822281}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585371637684.76/warc/CC-MAIN-20200406133533-20200406164033-00284.warc.gz"} |
https://robotics.stackexchange.com/questions/21523/how-to-obtain-the-state-space-representation-of-a-computed-torque-control-system | # How to obtain the state space representation of a computed torque control system?
Assuming I have a system:
$$a \, \ddot{x}_1 + b \, \ddot{x}_2 + c \,\dot{x_1} + d \,\dot{x_2} + e = u_1 \\ f \, \ddot{x}_1 + g \, \ddot{x}_2 + h \,\dot{x_1} + i \,\dot{x_2} + j = u_2$$
How would I write this system in state space representation: $$\dot{x} = Ax+Bu$$ $$y = Cx + Du$$
Usually, I would isolate for $$\ddot{x_1}$$ or $$\ddot{x_2}$$, but in this case, they are functions of each other. Would the only way be to rewrite the dynamics in matrix form after setting new state variables?
• The fact they are coupled makes no difference. You can use your standard methodology. :), set one for x2 and x1 and then solve. Dec 20, 2020 at 9:07
First, isolate the second order from the other terms:
$$a \, \ddot{x}_1 + b \, \ddot{x}_2 =- c \,\dot{x_1} - d \,\dot{x_2} - e + u_1 \\ f \, \ddot{x}_1 + g \, \ddot{x}_2 = - h \,\dot{x_1} - i \,\dot{x_2} - j + u_2$$
Then, put it in a matrix form:
$$\left[\begin{matrix}a&b\\f&g\end{matrix}\right]\left[\begin{matrix}\ddot{x_1}\\\ddot{x_2}\end{matrix}\right]=\left[\begin{matrix}- c \,\dot{x_1} - d \,\dot{x_2} - e + u_1\\- h \,\dot{x_1} - i \,\dot{x_2} - j + u_2\end{matrix}\right].$$
Supposing $$\left[\begin{smallmatrix}a&b\\f&g\end{smallmatrix}\right]$$ is invertible, we can left multiply both sides by $$\left[\begin{smallmatrix}a&b\\f&g\end{smallmatrix}\right]^{-1}$$:
$$\left[\begin{matrix}a&b\\f&g\end{matrix}\right]^{-1}\left[\begin{matrix}a&b\\f&g\end{matrix}\right]\left[\begin{matrix}\ddot{x_1}\\\ddot{x_2}\end{matrix}\right]=\left[\begin{matrix}a&b\\f&g\end{matrix}\right]^{-1}\left[\begin{matrix}- c \,\dot{x_1} - d \,\dot{x_2} - e + u_1\\- h \,\dot{x_1} - i \,\dot{x_2} - j + u_2\end{matrix}\right].$$
Thus, we get: $$\left[\begin{matrix}\ddot{x_1}\\\ddot{x_2}\end{matrix}\right] = {1\over ag-bf} \left[\begin{matrix}g&-b\\-f&a\end{matrix}\right]\left[\begin{matrix}- c \,\dot{x_1} - d \,\dot{x_2} - e + u_1\\- h \,\dot{x_1} - i \,\dot{x_2} - j + u_2\end{matrix}\right],$$
$$\left[\begin{matrix}\ddot{x_1}\\\ddot{x_2}\end{matrix}\right] = {1\over ag-bf} \left[\begin{matrix}(bh-gc)\dot{x_1}+(bi-gd)\dot{x_2}+(bj-je)\\ (fc-ah)\dot{x_1}+(fd-ai)\dot{x_2} + (fe-aj)\end{matrix}\right] +{1\over ag-bf} \left[\begin{matrix} g&-b\\ -f&a \end{matrix}\right] \left[\begin{matrix} u_1\\ u_2 \end{matrix}\right].$$
Using auxiliary variables: $$\left[\begin{matrix}\ddot{x_1}\\\ddot{x_2}\end{matrix}\right] = \left[\begin{matrix}\alpha\dot{x_1}+\beta\dot{x_2}+\gamma\\ \delta\dot{x_1}+\epsilon\dot{x_2} + \zeta\end{matrix}\right] + \left[\begin{matrix} \eta&\theta\\ \iota&\kappa \end{matrix}\right] \left[\begin{matrix} u_1\\ u_2 \end{matrix}\right].$$
Here, $$\gamma$$ and $$\zeta$$ can represent either uncontrolled inputs or disturbances.
As uncontrolled inputs: $$\left[\begin{matrix}\ddot{x_1}\\\ddot{x_2}\end{matrix}\right] = \left[\begin{matrix}\alpha\dot{x_1}+\beta\dot{x_2}\\ \delta\dot{x_1}+\epsilon\dot{x_2}\end{matrix}\right] + \left[\begin{matrix} \eta&\theta&\gamma\\ \iota&\kappa&\zeta \end{matrix}\right] \left[\begin{matrix} u_1\\ u_2\\ 1 \end{matrix}\right].$$
As disturbances: $$\left[\begin{matrix}\ddot{x_1}\\\ddot{x_2}\end{matrix}\right] = \left[\begin{matrix}\alpha\dot{x_1}+\beta\dot{x_2}\\ \delta\dot{x_1}+\epsilon\dot{x_2}\end{matrix}\right] + \left[\begin{matrix} \eta&\theta\\ \iota&\kappa \end{matrix}\right] \left[\begin{matrix} u_1\\ u_2 \end{matrix}\right]+ \left[\begin{matrix} \gamma\\ \zeta \end{matrix}\right].$$
Creating the state $$s=[s_1\;s_2\;s_3\;s_4]^T=[x_1\;\dot{x_1}\;x_2\;\dot{x_2}]^T$$:
$$\dot{s} = \dot{\left[\begin{matrix}s_1\\ s_2\\ s_3\\ s_4\end{matrix}\right]} = \left[\begin{matrix} 0&1&0&0\\ 0&\alpha&0&\beta\\ 0&0&0&1\\ 0&\delta&0&\epsilon \end{matrix}\right] \left[\begin{matrix}s_1\\ s_2\\ s_3\\ s_4\end{matrix}\right] + \left[\begin{matrix} 0&0\\ \eta&\theta\\ 0&0\\ \iota&\kappa \end{matrix}\right] \left[\begin{matrix} u_1\\ u_2 \end{matrix}\right] + \left[\begin{matrix} 0\\ \gamma\\ 0\\ \zeta \end{matrix}\right].$$
Depending on your system, you can design a controller that rejects those disturbances; the presence of integrators in the system can help remove steady-state errors.
• Thank you. Is this generally the way computed torque control is done? I am wondering if it would be possible to transform this into a second order state space by representing x1 and x2 in a single vector q = [x1;x2]? Dec 20, 2020 at 17:23
• In youtube.com/watch?v=MV-xBPP3H2k, you can see that a combination of feedfoward and PID can be used to control using the torque as input. Dec 21, 2020 at 16:30
\begin{align} a \, \ddot{x}_1 + b \, \ddot{x}_2 + c \,\dot{x_1} + d \,\dot{x_2} + e &= u_1 \tag{1} \\ f \, \ddot{x}_1 + g \, \ddot{x}_2 + h \,\dot{x_1} + i \,\dot{x_2} + j &= u_2 \tag{2} \end{align} Let's write Eq(1) without $$\ddot{x}_2$$, hence: \begin{align} a \, \ddot{x}_1 + b \, \Big[\frac{u_2-f \, \ddot{x}_1 - h \,\dot{x}_1 - i \,\dot{x}_2 - j}{g}\Big] + c \,\dot{x}_1 + d \,\dot{x}_2 + e &= u_1 \\ \left[a-\frac{bf}{g} \right] \, \ddot{x}_1 + \, \frac{b}{g}u_2 - \frac{bh}{g} \,\dot{x}_1 - \frac{bi}{g} \,\dot{x}_2 - \frac{b}{g}j + c \,\dot{x}_1 + d \,\dot{x}_2 + e &= u_1 \\ % \left[a-\frac{bf}{g} \right] \, \ddot{x}_1 = u_1 - \, \frac{b}{g}u_2 + \frac{bh}{g} \,\dot{x}_1 + \frac{bi}{g} \,\dot{x}_2 + \frac{b}{g}j - c \,\dot{x}_1 - d \,\dot{x}_2 - &e \\ % \ddot{x}_1 = \left[\frac{g}{(ag-bf)} \right] \left[u_1 - \, \frac{b}{g}u_2 + \frac{bh}{g} \,\dot{x}_1 + \frac{bi}{g} \,\dot{x}_2 + \frac{b}{g}j - c \,\dot{x}_1 - d \,\dot{x}_2 - e\right] \tag{3} \end{align} Now we do same procedure which is eliminating $$\ddot{x}_1$$ from Eq(2) hence, \begin{align} f \, \Big[\frac{u_1- b \, \ddot{x}_2 - c \,\dot{x_1} - d \,\dot{x_2} - e}{a}\Big] + g \, \ddot{x}_2 + h \,\dot{x_1} + i \,\dot{x_2} + j &= u_2 \\ % \Big[ g - \frac{fb}{a}\Big] \ddot{x}_2 + \frac{f}{a} u_1 - \frac{fc}{a} \,\dot{x_1} - \frac{fd}{a} \,\dot{x_2} - \frac{fe}{a} + h \,\dot{x_1} + i \,\dot{x_2} + j &= u_2 \\ % \Big[ g - \frac{fb}{a}\Big] \ddot{x}_2 = u_2 - \frac{f}{a} u_1 + \frac{fc}{a} \,\dot{x_1} + \frac{fd}{a} \,\dot{x_2} + \frac{fe}{a} - h \,\dot{x_1} - i \,\dot{x_2} - j \\ % \ddot{x}_2 = \left[\frac{a}{(ag-bf)} \right] \left[ u_2 - \frac{f}{a} u_1 + \frac{fc}{a} \,\dot{x_1} + \frac{fd}{a} \,\dot{x_2} + \frac{fe}{a} - h \,\dot{x_1} - i \,\dot{x_2} - j \right] \tag{4} \end{align} Now let $$y_1=x_1, y_2=\dot{x}_1, y_3=x_2, y_4=\dot{x}_2$$, hence: \begin{align} \dot{y}_1 &= y_2 \\ \dot{y}_2 &= \left[\frac{g}{(ag-bf)} \right] \left[u_1 - \, \frac{b}{g}u_2 + \Big[\frac{bh-cg}{g}\Big] \,y_2 + \Big[\frac{bi-dg}{g} \Big] \,y_4 + \frac{bj-eg}{g}\right] \\ \dot{y}_3 &= y_4 \\ \dot{y}_4 &= \left[\frac{a}{(ag-bf)} \right] \left[ u_2 - \frac{f}{a} u_1 + \Big[\frac{fc-ha}{a} \,\Big] y_2 + \Big[\frac{fd-ia}{a}\Big] \,y_4 + \frac{fe-aj}{a} \right] \end{align}
where $$ag\neq bf$$. You can proceed from here.
Before the question can be answered with mathematical terms, a bit meta knowledge may help to understand the thought system. The goal of creating a state space formula for robotics problems is a typical application of the matlab software. The students are educated how to use a commercial software package for describing real world problems.
With this pre-knowledge in mind it is much easier to identify the correct answer. It was given in the internet already under the URL https://in.mathworks.com/help/control/getstart/linear-lti-models.html The website explains, how to use the famous mathematical software for creating a state space model for a torgue control. What is provided too, is how to create the differential equations and transform them into the matrix notation.
• Students are educated on such easy equations to write them out by hand and learn the method, then use software. I don’t know of any good university that would teach students to write a state space model in Matlab, this isn’t a helpful answer on the method on how to write in state space methodology, coming from a poor basis to suggest that universities teach only to use commercial software, particularly for such a simple example. Dec 20, 2020 at 9:04 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 27, "wp-katex-eq": 0, "align": 4, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.999848484992981, "perplexity": 2132.4689751337414}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296948932.75/warc/CC-MAIN-20230329023546-20230329053546-00048.warc.gz"} |
https://www.physicsforums.com/threads/the-set-of-ring-automorphisms-is-an-abstract-group-under-composition.162011/ | # Homework Help: The set of ring automorphisms is an abstract group under composition
1. Mar 22, 2007
### catcherintherye
1. The problem statement, all variables and given/known data
Aut(R) denotes the set of ring automorphisms of a ring R Show formally that Aut(R) is a group under composition.
2. Relevant equations
3. The attempt at a solution
I Have a very similar question to which I have the solution viz
Aut(G) denotes the set of group automorphisms of a Group G, show that Aut(G) is a group under composition.
Proof Let a,b: G -> G be automorphisms
then $$a\circ b: G \rightarrow g is also an auto$$
$$(a\circ b)(xy) = a(b(xy))=a(b(x)b(y))= a(b(x))a(b(y))$$
$$=(a\circ b)(x)(a\circ b)(y)$$
so $$a\circb$$ is a homomorphism
it is also bijective since a,b are bijective
$$\circ: aut(G)\times aut(G) \rightarrow aut(G)$$
is automatically associative (because comp of mappings is associative)
As identity in Aut(G) $$take Id_g:G \rightarrow G$$
finally inverses
Let a: G --> G be an auto
then a^-1:G -->G is atleast a mapping and bijective
need only show
$$a^-1(xy) = a^-1(x)a^-1(y)$$
let $$x,y \in G$$
choose $$c,d \in G$$ : a(c)=x, a(d)=y
$$a^-1(xy) = a^-1(a(c)a(d))=a^-1(a(cd)) = cd= a^-1(x)a^-1(y)$$
q.e.d
.......the proof for rings is essentially the same right? The only thing that concerns me is the last part(above) since we used the fact that every element has it's inverse in a group but we don't have that in a ring....
Last edited: Mar 22, 2007
2. Mar 22, 2007
### matt grime
Where have you used that fact?
3. Mar 22, 2007
### catcherintherye
ok so i haven't and these two proofs are essentially the same?
4. Mar 22, 2007
### HallsofIvy
You did use a-1 where a is automorphism. You say you know
Are you sure of that definition of Aut(G)? Homomorphism, in general, do not have inverses.
5. Mar 22, 2007
### catcherintherye
no i've made a mistake it's supposed to be the group of isomorphisms | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9814321994781494, "perplexity": 1875.408790259568}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794866870.92/warc/CC-MAIN-20180524205512-20180524225512-00601.warc.gz"} |
https://www.tenebre.xyz/math-geometry-triangles.html | ## Triangles
### Area of a Triangle
There are numerous ways to determine the area of a triangle. Each calculation method depends on what information is already known about the triangle in question.
Given the height and width of a right triangle, the area is simply:
$$A=\frac{1}{2}ab$$
Given the height and and base edge length of any triangle, the area is similarly:
$$A=\frac{1}{2}bh$$
Given one angle and is adjacent lengths, the area is:
$$A=\frac{1}{2}bc\,sin\,α$$
Given one side and its two adjacent angles, the area is:
$$A=\frac{a^2\,sin\,α\,sin\,β}{2\,sin(α+β)}$$
Given all three side lengths, we use Heron's formula (aka Hero's formula):
$$A=\sqrt{s(s-a)(s-b)(s-c)}$$
Where $$s$$ is the semiperimeter:
$$s=\frac{1}{2}(a+b+c)$$
Note that a circle inscribed within any triangle has the property:
$$r=\frac{A}{s}$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8626473546028137, "perplexity": 568.5107548817107}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296945182.12/warc/CC-MAIN-20230323163125-20230323193125-00226.warc.gz"} |
https://www.thphys.uni-heidelberg.de/~cosmo/dokuwiki/doku.php/doran:cmb | The Theory of the Cosmic Microwave Background
Topics
In this course, we cover the theory of the cosmic microwave background fluctuations. In particular:
• The expanding universe
• Stokes parameters, spin harmonics and E and B modes
• Cosmological perturbations
• Gauge freedom and gauge transformations
• The Boltzmann equation for photons
• The scattering terms of Boltzmann's equation for photons
• The multipole expansion
• The line of sight strategy of solving the multipole hierachy
• The multipole spectrum of temperature and polarization fluctuations
• Finding initial conditions for the fluctuations
• The tight coupling limit before recombination
• Analytic estimates
• If time permits: secondary anisotropies
Lecture Notes
You can download the lecture notes new from 02-05-2010 (without a chapter on secondary anisotropies yet).
Further Literature
• The Cosmic Microwave Background, by Ruth Durrer (2008) ISBN-10: 0521847044
• Principles of Physical Cosmology by P.J.E Peebles (1993) ISBN-10: 0691019339
• Fluctuations in the Cosmic Microwave Background, Matthias Zaldarriaga's Thesis
• Gauge Invariant Cosmological Perturbations, J. M. Bardeen (1980), Phys.Rev.D22:1882-1905,1980
Credit Points
Master students may acquire 4 credit points subject to a written exam at the end of the course. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8792506456375122, "perplexity": 4814.93816804474}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195529276.65/warc/CC-MAIN-20190723105707-20190723131707-00013.warc.gz"} |
https://people.math.osu.edu/gubkin.1/Khan-khan-exercises-a1978a3/exercises/fractions_cut_and_copy_1.html | randRangeWeighted(3, 12, 1, 1 / 6) D_PARENT === 1 ? randRange(3, 12) : (rand(5) > 0 ? D_PARENT : 1)
D_PARENT === 1 ? randRange(1, 4) : randRangeExclude(2, 2 * D_PARENT - 1, [D_PARENT]) D_OFFSPRING === 1 ? randRange(1, 4) : randRangeExclude(2, 2 * D_OFFSPRING - 1, [D_OFFSPRING])
D_PARENT === 1 ? N_PARENT : mixedOrImproper(N_PARENT, D_PARENT) D_OFFSPRING === 1 ? N_OFFSPRING : mixedOrImproper(N_OFFSPRING, D_OFFSPRING) N_PARENT / D_PARENT N_OFFSPRING / D_OFFSPRING OFFSPRING / PARENT D_PARENT === 1 ? D_OFFSPRING : D_PARENT N_PARENT * (D_PARENT === 1 ? D : 1) N_OFFSPRING * (D_OFFSPRING === 1 ? D : 1)
The starting block below is CODE_PARENT units long. Use the tools to the right to convert the starting block into the goal block that is CODE_OFFSPRING units long. You can see your progress as the current block.
Starting Block:
initSliceClone(["current_block"]); init({range: [[0, 1], [0, 1]], scale: [500, 25 ]}); rectchart([1, 0], ["#e00", "#999"]);
Current Block:
init({ range: [[0, 1], [0, 1] ], scale: [500, 25]}); rectchart([1, 0], ["#e00", "#999"]);
Goal Block:
init({range: [[0, 1], [0, 1]], scale: [500 * ANSWER, 25]}); rectchart([1, 0], [BLUE, "#999"]);
Cut into 1 piece
Copy 1 time
[pieces, times['current_block']]
return roundTo(3, guess[1] / guess[0]) === roundTo(3, ANSWER);
pieces = guess[0]; times['current_block'] = guess[1]; updateGraphAndAnswer();
$('#pieces').text(plural(guess[0], 'piece'));$('#current_block_times').text(plural(guess[1], 'time'));
The starting block of length CODE_PARENT units can be rewritten as fraction(N_PARENT_EXPANDED, D).
The goal block of length CODE_OFFSPRING units can be rewritten as fraction(N_OFFSPRING_EXPANDED, D).
Cutting the starting block into x pieces is the same as dividing it by x.
Therefore cutting the starting block into N_PARENT_EXPANDED pieces is the same as:
\dfrac{N_PARENT_EXPANDED}{D} ÷ N_PARENT_EXPANDED = \dfrac{N_PARENT_EXPANDED}{D} \cdot \dfrac{1}{N_PARENT_EXPANDED} = \dfrac{1}{D}
Copying the resulting block y times is the same as multiplying it by y.
Therefore copying the resulting block N_OFFSPRING_EXPANDED times is the same as:
\dfrac{1}{D} \cdot N_OFFSPRING_EXPANDED = \dfrac{N_OFFSPRING_EXPANDED}{D}
Notice that we end up with a block the same size as the goal block.
Therefore the solution is to cut the starting block into N_PARENT_EXPANDED pieces and copy the resulting block N_OFFSPRING_EXPANDED times. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.711607038974762, "perplexity": 19758.229033142612}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934806676.57/warc/CC-MAIN-20171122213945-20171122233945-00419.warc.gz"} |
http://mathematica.stackexchange.com/questions/30721/mathematica-not-plotting-whole-logarithmic-function | # Mathematica not plotting whole logarithmic function
I am trying to use the following input
Plot[Log[E,x+1],{x,-50,50},PlotRange->50]
however the output is:
How can I adjust it so the line goes down to the PlotRange mark specified. Or is this a limitation of mathematica?
-
Your question is not especially original, it's going to be closed in a while. I'd do this: Plot[{Re@#, Im@#}&@Log[x + 1], {x, -50, 50}, Evaluated -> True, PlotStyle -> Thick], PlotRange serves a different purpose than you seem to expect, see documentation pages. – Artes Aug 19 '13 at 9:46
I just tried that and got the following: Link To Graph – VikeStep Aug 19 '13 at 9:53
Does it make you wonder? If it does, start to learn complex functions, there are many helpful questions. – Artes Aug 19 '13 at 9:59
It's a problem of how Plot[] works. There is only one pixel per x-value, and the curve at x=-1 is so steep that it doesn't take up more than one pixel in width. Use this instead: ParametricPlot[{x, Log[x + 1]}, {x, -1, 3}, PlotRange -> {{-2, 3}, {-10, 2}}] – Volker Aug 19 '13 at 10:12
@SjoerdC.deVries This poor question is not even a bit clear what the OP wants, why not e.g. Plot[Log[x + 1], {x, -2, 50}, PlotRange -> {{-2, 50}, All}] – Artes Aug 19 '13 at 12:23
As I mentioned in the comments, it's a problem of Plot[]. Mathematica won't draw more than one pixel per pixel column. So I'd use ParametricPlot instead, which makes it a little better, but still not perfect. The line becomes so steep that you can't tell the difference between it and a straight line, so you just extend it manually:
ParametricPlot[{{x, Log[x + 1]}, {-1, -x - 9}}, {x, -2, 50},
PlotRange -> {{-2, 50}, {-50, 10}}, PlotStyle -> {Blue, Blue}]
-
Works perfectly, I decided to use a method similar to this, I still used Plot, but I added Epilog->Line[{{-1,-4},{-1,50}}] – VikeStep Aug 19 '13 at 10:29
@user9053 I don't think your soulution is in any way similar to the one given here. – Sjoerd C. de Vries Aug 19 '13 at 12:59
what I'm saying is, is that he explained why it wasn't working and said that I should manually extend the line, so instead of manually extending it in ParametricPlot, I did it in Plot – VikeStep Aug 20 '13 at 7:21
This is what I'd do, the idea is to use ParametricPlot[{b^y, y}] for Log[b, x]. So we can use Solve to make it a little bit more general:
Block[{x, y},
With[{notimportantoptions = Sequence[PlotStyle -> Thick, PlotRange -> {All, {-25, 6}},
AspectRatio -> 1, AxesStyle -> [email protected],
AxesOrigin -> {0, 0}, BaseStyle -> {18, Bold}]
},
ParametricPlot[{x, y} /. Solve[y == 2 Log[15 + x], x, Reals][[1]], {y, -25, 6},
RegionFunction -> (# < 10 &), notimportantoptions, Evaluated -> True]
]]
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.35374343395233154, "perplexity": 2293.56999146499}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-11/segments/1424936463475.57/warc/CC-MAIN-20150226074103-00040-ip-10-28-5-156.ec2.internal.warc.gz"} |
https://online.stat.psu.edu/stat200/book/export/html/216 | # 10.4 - Minitab Express: One-Way ANOVA
10.4 - Minitab Express: One-Way ANOVA
In one research study, 20 young pigs are assigned at random among 4 experimental groups. Each group is fed a different diet. (This design is a completely randomized design.) The data are the pigs' weights in kg after being raised on these diets for 10 months. We wish to ask whether mean pig weights are the same for all 4 diets.
• $H_0: \mu_1 = \mu_2 = \mu_3 = \mu_4$
• $H_a:$ Not all $\mu$ are equal
Data from study of pigs weights
Feed_1 Feed_2 Feed_3 Feed_4
60.8 68.3 102.6 87.9
57.1 67.7 102.2 84.7
65.0 74.0 100.5 83.2
58.7 66.3 97.5 85.8
61.8 69.9 98.9 90.3
Contained in the Minitab Express file:
Note that in this file the data were entered so that each group is in its own column. In other words the responses are in a separate column for each factor level. In later examples you will see that Minitab Express will also conduct a one-way ANOVA if the responses are all in one column with the factor codes in another column.
## MinitabExpress – One-Way ANOVA
To perform an Analysis of Variance (ANOVA) test in Minitab Express:
1. Open the ANOVA_ex.MTW data set.
2. From the menu bar, select Statistics ANOVA One-Way ANOVA.
3. Click the drop-down menu and select "Responses are in a separate column for each factor level".
4. Double-click on the variables Feed_1Feed_2Feed_3, and Feed_4 to insert them into the "Responses" box.
5. Click the comparisons tab and check the box next to "Tukey (family error rate)".
6. Click OK.
The result should be the following output:
Null hypothesis All means are equal At least one mean is different $\alpha=0.05$
Equal variances were assumed for the analysis
Factor Information
Factor Levels Values
Factor 4 Feed_1, Feed_2, Feed_3, Feed_4
Analysis of Variance
Factor 3 4703.188 1567.72933 206.72 <0.0001
Error 16 121.340 7.58375
Total 19 4824.528
Model Summary
2.75386093 97.48% 97.01% 96.07%
Means
Factor N Mean StDev 95% CI
Feed_1 5 60.680 3.028 (58.069, 63.291)
Feed_2 5 69.240 2.958 (66.629, 71.851)
Feed_3 5 100.3400 2.1640 (97.7292, 102.9508)
Feed_4 5 86.380 2.782 (83.769, 88.991)
Pooled StDev = 2.75386093
Grouping Information Using the Tukey Method and 95% Confidence
Factor N Mean Grouping
Feed_3 5 100.34 A
Feed_4 5 86.38 B
Feed_2 5 69.24 C
Feed_1 5 60.68 D
Means that do not share a letter are significantly different.
Tukey Simultaneous Tests for Differences of Means
Difference of Levels Difference of Means SE of Difference 95% CI T-Value Adjusted P-Value
Feed_2-Feed_1 8.560 1.742 (3.572, 13.548) 4.91 0.0008
Feed_3-Feed_1 39.660 1.742 (34.672, 44.648) 22.77 <0.0001
Feed_4-Feed_1 25.700 1.742 (20.712, 30.688) 14.76 <0.0001
Feed_3-Feed_2 31.100 1.742 (26.112, 36.088) 17.86 <0.0001
Feed_4-Feed_2 17.140 1.742 (12.152, 22.128) 9.84 <0.0001
Feed_4-Feed_3 -13.960 1.742 (-18.948,-8.972) -9.02 <0.0001
Individual confidence level = 98.87%
Video Walkthrough
Select your operating system below to see a step-by-step guide for this example.
[1] Link ↥ Has Tooltip/Popover Toggleable Visibility | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4479590356349945, "perplexity": 8294.128572684484}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250590107.3/warc/CC-MAIN-20200117180950-20200117204950-00557.warc.gz"} |
http://www.ms.u-tokyo.ac.jp/preprint/2012/ | ## UTMS Preprint Series 2012
UTMS
2012-1
Takashito Kashiwabara On a strong solution of the non-stationary Navier-Stokes equations under slip or leak boundary conditions of friction type pdf
UTMS
2012-2
Issei Oikawa Hybridized discontinuous Galerkin method for convection-diffusion-reaction problems pdf
UTMS
2012-3
O. Yu. Imanuvilov and M. Yamamoto Inverse problem by Cauchy data on arbitrary subboundary for system of elliptic equations pdf
UTMS
2012-4
Takashi Kato, Akihiko Takahashi and Toshihiro Yamada An asymptotic expansion for solutions of Cauchy-Dirichlet problem for second order parabolic PDEs and its application to pricing barrier options pdf
UTMS
2012-5
Takashi kato Stock price fluctuations in an agent-based model with market liquidity pdf
UTMS
2012-6
Inwon C. Kim and Norbert Po\v{z}\'ar Nonlinear elliptic-parabolic problems pdf
UTMS
2012-7
Kazuki Okamura Some regularity results for a certain class of de Rham's functional equations and stationary measures pdf
UTMS
2012-8
K. Aihara, K. Ito, J. Nakagawa and T. Takeuchi Optimal control laws for traffic control pdf
UTMS
2012-9
Guanyu Zhou Analysis of the fictitious domain method with $H^1$-penalty for parabolic problem pdf
UTMS
2012-10
Kiyoomi Kataoka and Nobuko Takeuchi A system of fifth-order partial differential equations describing a surface which contains many circles pdf
UTMS
2012-11
Ken'ichi Yoshida The minimal volume orientable hyperbolic 3-manifold with 4 cusps pdf
UTMS
2012-12
Hajime Fujita, Mikio Furuta and Takahiko Yoshida Geodesic flows on spheres and the local Riemann-Roch numbers pdf
UTMS
2012-13
H. Kawakami, A. Nakamura, and H. Sakai Degeneration scheme of 4-dimensional Painlev\'e-type equations pdf
UTMS
2012-14
Yusaku Tiba The second main theorem for entire curves into Hilbert modular surfaces pdf
UTMS
2012-15
O. Yu. Imanuvilov and M. Yamamoto Inverse boundary value problem for Schr\"odinger equation in cylindrical domain by partial boundary data pdf
UTMS
2012-16
Nao Hamamuki A discrete isoperimetric inequality on lattices pdf
UTMS
2012-17
Nao Hamamuki Asymptotically self-similar solutions to curvature flow equations with prescribed contact angle and their applications to groove profiles due to evaporation-condensation pdf
UTMS
2012-18
Guanyu Zhou Analysis of the fictitious domain method with $L^2$-penalty for elliptic and parabolic problems pdf | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.49942269921302795, "perplexity": 4193.013328938137}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-17/segments/1524125937113.3/warc/CC-MAIN-20180420022906-20180420042906-00552.warc.gz"} |
https://socratic.org/questions/what-is-the-slope-of-the-line-perpendicular-to-y-5-3x-3 | Algebra
Topics
# What is the slope of the line perpendicular to y=-5/3x -3 ?
Feb 4, 2016
The slope of a line perpendicular to a line with slope $m$ is $- \frac{1}{m}$. The line we are looking for, therefore, has a slope of $\frac{3}{5}$.
#### Explanation:
Standard form of a line is:
$y = m x + b$ where $m$ is the slope and $b$ is the y-intercept.
For another line perpendicular, the slope will be $- \frac{1}{m}$. In this case, that is $- \frac{1}{- \frac{5}{3}}$ = $\frac{3}{5}$.
##### Impact of this question
726 views around the world | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 9, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8169571161270142, "perplexity": 335.9361587746539}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496671053.31/warc/CC-MAIN-20191121231600-20191122015600-00020.warc.gz"} |
https://byjus.com/trapezoid-formula/ | # Trapezoid formula
In Geometry, a trapezium is one of the types of a quadrilateral with one pair of parallel sides (called bases) and one pair of non-parallel sides (called legs). The area of a trapezoid is the number of unit squares that can be fit into the trapezoid. It is generally measured using square units, such as cm2, m2, and so on. In this article, we are going to learn the area of trapezoid formula and examples in detail.
## Area of Trapezoid Formula
To find the area of trapezoid, it is enough to know the bases (parallel sides) of trapezoid and the perpendicular distance between them.
If “a” and “b” are the parallel sides of trapezoid and “h” is the perpendicular distance between, then the area of trapezoid formula is given by:
Area of Trapezoid = (½) [(a+b)h] square units.
### Examples on Area of Trapezoid
Example 1:
Find the area of trapezoid if the bases of the trapezoid are 6 cm and 7 cm and the perpendicular distance between them is 8 cm.
Solution:
Given:
Let the parallel sides of a trapezium be “a” and “b”.
Hence, a = 6 cm and b = 7 cm.
Also, given that the perpendicular distance between the parallel sides is 8 cm.
(i.e) h = 8 cm.
We know that the area of trapezoid formula is:
A = (½) [(a+b)h] square units
Now, substitute the values in the formula, we get
A = (½) [(6+7)8] square units
A = (6+7)4 cm2
A = (13)4 cm2
A = 52 cm2
Therefore, the area of trapezoid is 52 cm2.
Example 2:
Find the height of the trapezoid, if the sum of the parallel sides is 25 m and the area is 75 m2.
Solution:
Given: a+b = 25 m
Area, A = 75 m2.
To find: h
We know that the formula for area of trapezoid, A = (½) [(a+b)h] square units
Substituting the values in the formula, we get
75 = (½)[25h]
75/25 = (½)h
3 = h/2
h = 6.
Therefore, the height of the trapezoid is 6 m.
Stay tuned to BYJU’S – The Learning App to learn more formulas.
## Frequently Asked Questions on Area of Trapezoid Formula
### What is the area of trapezoid?
The area of trapezoid is the number of unit squares that fit into the trapezoid shape. In other words, the region occupied by the trapezoid shape is called the area of trapezoid. It is measured in square units.
### What is the area of trapezoid formula?
If “a” and “b” are the parallel sides of trapezoid, and “h” is the perpendicular distance between them, then the area of trapezoid formula is (½) [(a+b)h] square units.
### Can we find the area of the trapezoid, if the bases and height are known?
Yes, we can find the area of trapezoid if the bases and height are known. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9180575609207153, "perplexity": 650.708375798142}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662541747.38/warc/CC-MAIN-20220521205757-20220521235757-00489.warc.gz"} |
https://www.fmf.uni-lj.si/si/obvestila/28995/ | Domov > Obvestila > Katarína Hrináková & Deborah Oliveros
# Katarína Hrináková & Deborah Oliveros
Datum objave: 14. 1. 2014
Vir: Seminar za teorijo grafov in algoritme
Četrtek 16. 1. 2014 ob 12:15 v 3.05 na Jadranski 21
12:15 - 13:00
Speaker: Katarína Hrináková, STU Bratislava
Title: Self-dual, self-Petrie-dual, and Möbius regular maps on linear fractional groups
Abstract: Maps are cellular embeddings of graphs on compact surfaces. Regular maps are maps with highest possible level of symmetry. A map is regular if its automorphism group acts regularly on the set of its flags. Enumeration and classification of regular maps is usually approached in three different ways - by supporting surfaces, by underlying graphs, and by automorphism groups. In this talk we focus on regular maps whose automorphism group is isomorphic to ${\rm PSL}(2,q)$ and ${\rm PGL}(2,q)$ and will characterize those maps which are self-dual, self-Petrie-dual, or Möbius.
13:15 - 14:00
Speaker: Deborah Oliveros, Universidad Nacional Autónoma de México
Title: Searching for perfection in hypergraphs
Abstract: Bipartite, interval graphs and transitive oriented graphs has been known as good examples of perfect graphs however not much is known about perfection in 3-hypergraphs, in this talk, we will present the family of oriended transitive 3-hypergraphs that arise from cyclic permutations and intervals in the circle, in order to search for the notion of perfection in hypergraphs. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5022546052932739, "perplexity": 2955.176271540053}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987763641.74/warc/CC-MAIN-20191021070341-20191021093841-00289.warc.gz"} |
https://piping-designer.com/index.php/properties/classical-mechanics/2273-stagnation-pressure | # Stagnation Pressure
Written by Jerry Ratzlaff on . Posted in Classical Mechanics
Stagnation pressure, abbreviated as $$p_s$$, is the pressure a fluid exerts when the velocity of the fluid is zero.
## Stagnation Pressure formula
$$\large{ p_s = \frac { 1 } { 2 } \; \rho\; v^2 + SP }$$
### Where:
$$\large{ p_s }$$ = stagnation pressure
$$\large{ \rho }$$ (Greek symbol rho) = density of fluid
$$\large{ v }$$ = velocity of fluid
$$\large{ SP }$$ = static pressure | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9597676396369934, "perplexity": 10572.210794340312}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618039610090.97/warc/CC-MAIN-20210422130245-20210422160245-00269.warc.gz"} |
http://www.thescinewsreporter.com/2018/04/astronomers-observe-strange-quantum.html | ### Astronomers Observe Strange Quantum Distortion in Empty Space for the First Time Ever
Vacuum birefringence is a weird quantum phenomenon that has only ever been observed on an atomic scale. It occurs when a neutron star is surrounded by a magnetic field so powerful and intense, so that it gives rise to a region in empty space where matter randomly appears and vanishes.
This polarization of light in a vacuum due to strong magnetic fields was first thought to be possible in the 1930s by physicists Werner Heisenberg and Hans Heinrich Euler as a product of the theory of quantum electrodynamics (QED). The theory describes how light and matter interact. Now, for the first time ever, this strange quantum effect has been observed by a team of scientists from INAF Milan (Italy) and from the University of Zielona Gora (Poland).
Using the European Southern Observatory’s (ESO) Very Large Telescope (VLT), a research team led by Roberto Mignani observed neutron star RX J1856.5-375, which is about 400 light-years from Earth. Neutron stars are rather dim, yet they are 10 times more massive than our sun. As such, they have extremely strong magnetic fields permeating their surface and surroundings.
Vacuums are supposedly empty spaces (according to Einstein and Newton, at least) where light can pass through uninhibited or unchanged. But, according to QED, space is full of virtual particles continually popping in and out of existence. Very strong magnetic fields, like those surrounding neutron stars, can modify such spaces as vacuums. Using the FORS2 instrument on the VLT, the researchers were able to observe the neutron star with just visible light, pushing the limits of existing telescope technology.
## Better Telescopes
Studying VLT data on the star, the researchers saw linear polarization occurring at a significant degree of around 16%. This is very likely due to vacuum birefringence in the area surrounding RX J1856.5-375.
“The high linear [polarization] that we measured with the VLT can’t be easily explained by our models unless the vacuum birefringence effects predicted by QED are included. [Polarization] measurements with the next generation of telescopes, such as ESO’s European Extremely Large Telescope (EELT), could play a crucial role in testing QED predictions of vacuum birefringence effects around many more neutron stars” said Mignani.
Given the limited technology used, Mignani believes that future telescopes can discover more about similar strange quantum effects by studying other neutron stars.
“This measurement, made for the first time now in visible light, also paves the way to similar measurements to be carried out at X-ray wavelengths,” researcher Kinwah Wu said. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8249076008796692, "perplexity": 1282.8533752625744}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195529406.97/warc/CC-MAIN-20190723130306-20190723152306-00557.warc.gz"} |
http://www.contrib.andrew.cmu.edu/~ryanod/index.php?p=2285&replytocom=22868 | # Some tips
• You might try using analysis of Boolean functions whenever you’re faced with a problems involving Boolean strings in which both the uniform probability distribution and the Hamming graph structure play a role. More generally, the tools may still apply when studying functions on (or subsets of) product probability spaces.
• If you’re mainly interested in unbiased functions, or subsets of volume $\frac12$, use the representation $f : \{-1,1\}^n \to \{-1,1\}$. If you’re mainly interested in subsets of small volume, use the representation $f : \{-1,1\}^n \to \{0,1\}$.
• As for the domain, if you’re interested in the operation of adding two strings (modulo $2$), use $\mathbb{F}_2^n$. Otherwise use $\{-1,1\}^n$.
• If you have a conjecture about Boolean functions:
• Test it on dictators, majority, parity, tribes (and maybe recursive majority of $3$). If it’s true for these functions, it’s probably true.
• Try to prove it by induction on $n$.
• Try to prove it in the special case of functions on Gaussian space.
• Try not to prove any bound on Boolean functions $f : \{-1,1\}^n \to \{-1,1\}$ that involves the parameter $n$.
• Analytically, the only multivariate polynomials we really know how to control are degree-$1$ polynomials. Try to reduce to this case if you can.
• Hypercontractivity is useful in two ways: (i) It lets you show that low-degree functions of independent random variables behave “reasonably”. (ii) It implies that the noisy hypercube graph is a small-set expander.
• Almost any result about functions on the hypercube extends to the case of the $p$-biased cube, and more generally, to the case of functions on products of discrete probability spaces in which every outcome has probability at least $p$ — possibly with a dependence on $p$, though.
• Every Boolean function consists of a junta part and Gaussian part.
### 5 comments to Some tips
• Ravi Boppana
Thanks for the tips! In the third tip (about the domain), should $\{ -1, 1 \}$ be $\{ -1, 1 \}^n$? Can you say a word about the rationale for the fifth tip (about the parameter $n$)?
• Ryan O'Donnell
You’re right about the third tip, thanks!
Regarding the 5th… well of course it’s not ironclad, but one of the themes in the area is to try to work in “$\{-1,1\}^\infty$” if possible. I guess I’m mainly thinking about theorems like hypercontractivity and the like (ones proven by induction) where one might be tempted to prove weaker versions with a dependence on $n$, but where it’s possible to prove something independent of $n$.
• Ravi Boppana
Thanks for the explanation. A million thanks for the entire book!
• Luca
Is there an “n-free” variant (generalization?) of KKL that has more or less the same applications?
• Luca: Yes, take a look at the “KKL Edge-Isoperimetric Theorem” in Chapter 9.6, which gives what I view as the “correct” version of the KKL theorem. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8858998417854309, "perplexity": 704.9663650579224}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891812841.74/warc/CC-MAIN-20180219211247-20180219231247-00778.warc.gz"} |
http://www.apniphysics.com/tag/fecl3-solution/ | Introduction Quinke’s Method In this video, I have discussed the calculation of the magnetic susceptibility by using the Quinke’s experiment. What are the important points for the measurement of… | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.87486332654953, "perplexity": 713.6268206991093}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-18/segments/1555578584186.40/warc/CC-MAIN-20190423015050-20190423041050-00248.warc.gz"} |
https://www.helpteaching.com/questions/155024/the-numbers-9-4-and-36-are-a-fact-family-which-number-senten | ##### Question Info
This question is public and is used in 93 tests or worksheets.
Type: Multiple-Choice
Category: Fact Families
Standards: 3.OA.B.5
Author: LBeth
View all questions by LBeth.
# Fact Families Question
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Add this question to a group or test by clicking the appropriate button below.
## Grade 3 Fact Families CCSS: 3.OA.B.5
The numbers 9, 4, and 36 are a fact family. Which number sentence is part of the fact family for these numbers?
1. $9 + 4 = 13$
2. $36 - 9 = 27$
3. $4 xx 9 = 36$
4. $36 -: 6 = 6$
You need to have at least 5 reputation to vote a question down. Learn How To Earn Badges. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.20150256156921387, "perplexity": 5475.095034817036}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891811243.29/warc/CC-MAIN-20180218003946-20180218023946-00165.warc.gz"} |
https://se4ml.org/unsupervised/chapter_hierarchical.html | # Hierarchical Clustering¶
Learning Objectives
• Understand hierarchical clustering algorithm
• Learn the binary tree and its properties
• Use the tree’s properties to gain insight of data
• Implement the algorithm for hierarchical clustering
## Limitations of the k-mean Algorithm¶
The previous chapter explains the k-mean clustering algorithm. It is simple and useful as an initial analysis of data but it also has several major problems:
• There is no obvious reason to select a particular value of k. The previous chapter shows an example: the data is generated for 10 clusters but the smallest distance occurs when k is 13.
• The algorithm is non-deterministic and it is often necessary running the same program multiple times.
• For a given cluster, there is no easy answer which other cluster is closer. It is possible to calculate the distances of centroids but this requires additional work.
• The k-mean algorithm assigns all data points to one of the k clusters in the very first step. Then the algorithm adjusts the clusters by the finding closest centroid from each data point. Because the initial assignments have direct impacts on the final results, the program often needs to run multiple times for selecting better results.
Hierarchical Clustering is a method that does not have these same problems as the k-mean algorithm.
## Examples of Hierarchical clustering¶
Hierarchical clustering iteratively finds the closest pair of clusters (at the beginning, each data point is a cluster by itself). The algorithm makes the pair two children of a binary tree. For hierarchical clustering, it is called dendrogram, instead of binary tree. This book uses both terms interchangably. The tree node becomes a new cluster. The algorithm continues until only one tree node is left. Before formally describing the algorithm, let us go through several examples. The simplest case is when there is only one data point but it is not very meaningful. Thus, let us start with two data points.
index
x
y
0
-66
45
1
95
-84
They are the two children of a binary tree:
Figure 51 Two data points are the two children of a binary tree.
Next, we consider the case when there are four data points:
index
x
y
0
-66
45
1
95
-84
2
-35
-70
3
26
94
We use the Euclidean distance here. Consider two data points: $$(x_a, y_a)$$ and $$(x_b, y_b)$$. The distance between them is defined as
$$\sqrt{(x_a - x_b)^2 + (y_a - y_b)^2}$$.
Consider three data points: $$(x_a, y_a)$$, $$(x_b, y_b)$$, and $$(x_c, y_c)$$. The following inequality is true.
$$\sqrt{(x_a - x_b)^2 + (y_a - y_b)^2} > \sqrt{(x_a - x_c)^2 + (y_a - y_c)^2} \Leftrightarrow ((x_a - x_b)^2 + (y_a - y_b)^2) > ((x_a - x_c)^2 + (y_a - y_c)^2)$$.
We care about only the order of the distance so we do not really care about the square root.
The following table shows $$(x_a - x_b)^2 + (y_a - y_b)^2$$ between the pairs of the data points.
0
1
2
3
0
0
42562
14186
10865
1
42562
0
17096
36445
2
14186
17096
0
30617
3
10865
36445
30617
0
The shortest distance (10865) occurs between $$(x_0, y_0)$$ and $$(x_3,y_3)$$. They are the first pair to be put into the same cluster. Thus, points 0 and 3 are the two children of the same parent node.
Figure 52 Clusters of four data points. Do not worry about the colors, nor the numbers along the vertical axis. Pay attention to the shape only.
How do we represent the cluster that includes points 0 and 3? There are several different commonly used representations. This example uses the centroid method: a cluster is represented by the centroid of the data points in the cluster. The cluster that contains $$(x_0, y_0)$$ and $$(x_3, y_3)$$ is represented by $$(\frac{-66+26}{2}, \frac{45+94}{2}) = (-20, 69.5)$$. This cluster is marked as the new $$(x_0, y_0)$$ and $$(x_3, y_3)$$ no longer exists. We can recompute the distances among the pairs of points:
TO DO: make the table align right
0
1
2
3
0
0
42562
14186
10865
1
42562
0
17096
36445
2
14186
17096
0
30617
3
10865
36445
30617
0
The shortest distance (10865) occurs between $$(x_0, y_0)$$ and $$(x_3,y_3)$$. They are the first pair to be put into the same cluster. Thus, points 0 and 3 are the two children of the same parent node.
How do we represent the cluster that includes points 0 and 3? There are several different commonly used representations. This example uses the centroid method: a cluster is represented by the centroid of the data points in the cluster. The cluster that contains $$(x_0, y_0)$$ and $$(x_3, y_3)$$ is represented by $$(\frac{-66+26}{2}, \frac{45+94}{2}) = (-20, 69.5)$$. This cluster is marked as the new $$(x_0, y_0)$$ and $$(x_3, y_3)$$ no longer exists. We can recompute the distances among the pairs of points:
TO DO: make the table align right
0
1
2
0
0.0
36787.25
19685.25
1
36787.25
0
17096
2
19685.25
17096
0
Now, the shortest distance (17096) occurs between $$(x_1, y_1)$$ and $$(x_2, y_2)$$. These two data points are the two children of a tree node. At this moment, there are only two clusters and they are the children of a binary tree node. The final result is shown below
Figure 53 Clusters of four data points. Do not worry about the colors, nor the numbers along the vertical axis. Pay attention to the shape only.
Next, let’s add two more data points.
index
x
y
0
-66
45
1
95
-84
2
-35
-70
3
26
94
4
15
20
5
66
-3
The pair-wise distances is shown below
0
1
2
3
4
5
0
0
42562
14186
10865
7186
19728
1
42562
0
17096
36445
17216
7402
2
14186
17096
0
30617
10600
14690
3
10865
36445
30617
0
5597
11009
4
7186
17216
10600
5597
0
3130
5
19728
7402
14690
11009
3130
0
The shortest distance (3130) occurs between $$(x_4, y_4)$$ and $$(x_5, y_5)$$. These two data points are the two children of a node. This cluster is represented by the centroid $$(\frac{15 + 66}{2}, \frac{20 + (-3)}{2}) = (\frac{81}{2}, \frac{17}{2}) = (40.5, 8.5)$$. The cluster is expressed as $$(x_4, y_4)$$ and $$(x_5, y_5)$$ is removed. Now there are four data points and one cluster. The distances are shown in the following table:
0
1
2
3
4
0
0
42562
14186
10865
12674.5
1
42562
0
17096
36445
11526.5
2
14186
17096
0
30617
11862.5
3
10865
36445
30617
0
7520.5
4
12674.5
11526.5
11862.5
7520.5
0
The smallest distance is 7520.5 and it is between $$(x_3, y_3)$$ and the cluster created earlier. Thus, $$(x_3, y_3)$$ and the cluster are put together by making them the two childrens of a binary tree node. This process continues until there is only cluster left. The final binary tree is shown below:
Figure 54 Cluster of the six data points.
The examples are generated using the following program:
#!/usr/bin/python3
from matplotlib import pyplot as plt
import numpy as np
import random
from scipy.spatial.distance import pdist
random.seed(1)
def distance(x1, y1, x2, y2):
# no need to take square root
# print (x1 - x2, y1 - y2)
return (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)
if __name__ == "__main__":
random.seed(1)
numdp = 6
x = []
for i in range(numdp):
x.append([random.randint(-100, 100),
random.randint(-100, 100)])
print (x)
dendrogram(Z)
plt.show()
pairdist = []
for i1 in range(numdp):
row = [0] * numdp
pairdist.append(row)
for i1 in range(numdp):
for i2 in range(numdp):
d = distance(x[i1][0], x[i1][1], x[i2][0], x[i2][1])
pairdist[i1][i2] = d
print ('pairdist', pairdist[i1])
## Hierarchical Clustering Algorithm¶
The hierarchical clustering algorithm starts by treating each data point as a cluster. Then it repetively finds the closest two clusters. These two clusters are the two children of a binary tree node and form one cluster. As a result, two clusters become one cluster. This process continues until only one cluster is left. The algorithm is described below:
Figure 55 Hierarchical Clustering Algorithm
## Define Distance of Two Clusters¶
The earlier examples use the centroid to express each cluster. Other definitions of clusters’ distances are also used. There are four commonly adopted definitions for the distance of two clusters (An Introduction to Statistical Learning by James, Witten, Hastie, and Tibshirani): complete, single, average, and centroid. They are described below.
Suppose $$A = \{a_1, a_2, ..., a_n\}$$ is a cluster and $$a_1$$, $$a_2$$, …, $$a_n$$ are the $$n$$ data points in this cluster. Suppose $$B = \{b_1, b_2, ..., b_m\}$$ is another cluster and $$b_1$$, $$b_2$$, …, $$b_m$$ are the $$m$$ data points in this cluster. The distance between these two clusters can be defined as
• Complete: Compute the pairwise distances of every point in $$A$$ and every point in $$B$$, then select the largest distance. Mathematically, the distance is defined as $$\underset{a_i \in A, b_j \in B}{\max}{|a_i - b_j|}$$. Here, $$|a_i - b_j|$$ means the distance of the two points.
• Single. This definition considers the smallest distance among all pairs of points in $$A$$ and $$B$$: $$\underset{a_i \in A, b_j \in B}{\min}{|a_i - b_j|}$$.
• Average. This definition computes the average of the pairwise distances: $$\frac{1}{n \times m} \underset{a_i \in A, b_j \in B}{\Sigma} {|a_i - b_j|}$$.
• Centroid. Find the centroid $$c_A$$ of $$A$$ and the centroid of $$c_B$$ of $$B$$ using in Chapter of k-mean. The distance of the two clusters is the distance of the two centroids: $$| c_A - c_B|$$.
## Implementation¶
### Data Structures¶
TO DO: Explain list and tree
### Procedure¶
To implement hierarchical clustering, we will use two types of data structures: binary tree node and list node. Each binary tree node represents a cluster. The original data points are stored in the leaf nodes and each data point is a cluster of its own. These binary tree nodes are stored in a list. In a binary tree, a node is a leaf if it has no child. Then, the cloest two clusters are fused together into a single cluster. The two clusters are removed from the list and the new cluster is added to the list. In each step, two clusters are removed and one cluster is added. As a result, the number of clusters is reduced by one in each step. This process continues until only one cluster is left.
TO DO: Make a figure
The program’s starting point is relatively simple. It accepts one argument as the input file. Please notice that it is different from the k-mean solution since hierarchical clustering does not need the value of k.
TO DO: Explain the code
#! /usr/bin/python
# main.py for hierarchical clustering
import sys
import cluster
import argparse
def checkArgs(argv = None):
parser = argparse.ArgumentParser(description='parse arguments')
help = 'name of the data file', default = 'data.txt')
help = 'distance definition',
choices = ('c', 's', 'a', 't'))
# four methods to measure distances between clusters:
# complete, single, average, centroid
args = parser.parse_args(argv)
return args
if __name__ == "__main__":
args = checkArgs(sys.argv[1:])
cluster.cluster(args)
# cluster.py for hierarchical clustering
import sys
from hclist import HCList
def cluster(args):
filename = args.filename
distdef = args.distance
try:
fhd = open(filename) # file handler
except:
sys.exit('open fail')
# create an empty hierarchical clustering list
hcl = HCList(distdef)
count = 0
for oneline in fhd:
data = map(int, oneline.split())
count = count + 1
# print "add to list", data
# print "--- finish reading file ---"
hcl.printList()
hcl.cluster()
print "--- final cluster ---"
hcl.printList()
# hctree.py for hierarchical
class TreeNode:
def __init__(self, val):
self.value = val
self.left = None
self.right = None
def printNode(self):
if (self == None):
return
if ((self.left == None) and
(self.right == None)):
print "Leaf: ", self.value
else:
print self.value
if (self.left != None):
self.left.printNode()
if (self.right != None):
self.right.printNode()
def getLeft(self):
return self.left
def getRight(self):
return self.right
def distanceComplete(self, trnd):
dist1 = self._distanceCompleteNode(trnd)
dist2 = dist1
dist3 = dist1
if (self.left != None):
dist2 = self._distanceCompleteNode(self.left, trnd)
if (self.right != None):
dist3 = self._distanceCompleteNode(self.right, trnd)
return max(dist1, dist2, dist3)
def distanceSingle(self, trnd):
return 0
def distanceAverage(self, trnd):
return 0
def distanceCentroid(self, trnd):
return 0
def _distance(self, sndnode):
sum = 0
for ind in range(len(self.value)):
dist = self.value[ind] - sndnode.value[ind]
sum = dist * dist
return sum
def _distanceCompleteNode(self, trnd):
# find the maximum distance of one node with all nodes in trnd
dist1 = self._distance(trnd)
dist2 = dist1
dist3 = dist1
if (trnd.left != None):
dist2 = self._distanceCompleteNode(self, trnd.left)
if (trnd.right != None):
dist3 = self._distanceCompleteNode(self, trnd.right)
return max(dist1, dist2, dist3)
from hctree import TreeNode
import sys
class ListNode:
def __init__(self, tn):
# double linked list, with after and before
# use after and before, not next and prev
# because next is already defined in Python
self.trnode = tn
self.after = None
self.before = None
class HCList:
def __init__(self, distdef):
# the list has a dummy node. It is both head and tail
trnd = TreeNode(None)
lsnd = ListNode(trnd)
self.tail = lsnd
self.dist = distdef # definition of distance
# add a cluster to the list
# a new cluster is stored in a tree node
# the tree node is added to the list
trnd = TreeNode(val)
lsnd = ListNode(trnd)
self.tail.after = lsnd
lsnd.before = self.tail
self.tail = lsnd
return trnd
def delete(self, lsnd):
# cannot delete the first node (dummy)
return
# delete the last node
if (lsnd == self.tail):
self.tail = self.tail.before
self.tail.after = None
return
# delete a node in the middle
before = lsnd.before
after = lsnd.after
before.after = after
after.before = before
def printList(self):
print "HCList::printList"
while (lsnd != None):
lsnd.trnode.printNode()
lsnd = lsnd.after
def distance(self, lsnd1, lsnd2):
if ((self.dist == 'c') or (self.dist == 'C')):
return lsnd1.distanceComplete(lsnd2)
if ((self.dist == 's') or (self.dist == 'S')):
return lsnd1.distanceSimple(lsnd2)
if ((self.dist == 'a') or (self.dist == 'A')):
return lsnd1.distanceAverage(lsnd2)
if ((self.dist == 't') or (self.dist == 'T')):
return lsnd1.distanceCentroid(lsnd2)
print ('Unknown method for calcuating distance')
return 0
def merge(self, trnd1, trnd2):
# value not used for non-leaf nodes
val = [-1] * len(trnd1.value)
trnd.left = trnd1
trnd.right = trnd2
trnd.printNode()
def cluster(self):
# this implementation is not efficient but it should
# be easy to understand
# remember that head is the dummy node
# at least two list nodes, not done yet
# distance of the first two list nodes as reference
lsnd2 = lsnd1.after
mindist = self.distance(lsnd1, lsnd2)
# find the pair of the smallest distance
flsnd = self.head.after # first list node
while (flsnd != self.tail):
slsnd = flsnd.after # second list node
while (slsnd != None):
dist = self.distance(flsnd, slsnd)
if (dist < mindist): # notice, no =
dist = mindist
lsnd1 = flsnd
lsnd2 = slsnd
slsnd = slsnd.after
flsnd = flsnd.after
# remove the two nodes that have the smallest distance
# from the list
print "merge", lsnd1.trnode.value, lsnd2.trnode.value
self.delete(lsnd1)
self.delete(lsnd2)
self.merge(lsnd1.trnode, lsnd2.trnode) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5094535946846008, "perplexity": 2032.8687409793022}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514575596.77/warc/CC-MAIN-20190922160018-20190922182018-00452.warc.gz"} |
https://www.econometrics-with-r.org/2-pt.html | This book is in Open Review. We want your feedback to make the book better for you and other students. You may annotate some text by selecting it with the cursor and then click the on the pop-up menu. You can also see the annotations of others: click the in the upper right hand corner of the page
# 2 Probability Theory
This chapter reviews some basic concepts of probability theory and demonstrates how they can be applied in R.
Most of the statistical functionalities in base R are collected in the stats package. It provides simple functions which compute descriptive measures and facilitate computations involving a variety of probability distributions. It also contains more sophisticated routines that, e.g., enable the user to estimate a large number of models based on the same data or help to conduct extensive simulation studies. stats is part of the base distribution of R, meaning that it is installed by default so there is no need to run install.packages("stats") or library("stats"). Simply execute library(help = "stats") in the console to view the documentation and a complete list of all functions gathered in stats. For most packages a documentation that can be viewed within RStudio is available. Documentations can be invoked using the ? operator, e.g., upon execution of ?stats the documentation of the stats package is shown in the help tab of the bottom-right pane.
In what follows, our focus is on (some of) the probability distributions that are handled by R and show how to use the relevant functions to solve simple problems. Thereby, we refresh some core concepts of probability theory. Among other things, you will learn how to draw random numbers, how to compute densities, probabilities, quantiles and alike. As we shall see, it is very convenient to rely on these routines. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5309183597564697, "perplexity": 639.9190094277835}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964363157.32/warc/CC-MAIN-20211205100135-20211205130135-00321.warc.gz"} |
https://indico.cern.ch/event/260380/ | TH String Theory Seminar
# Double-Detector Correlations in N=4 SYM
## by Stefan Hohenegger
Europe/Zurich
4-3-006 - TH Conference Room (CERN)
### 4-3-006 - TH Conference Room
#### CERN
100
Show room on map
Description In this talk I will consider double-correlations of energy-, charge- and scalar-flow operators in four-dimensional N=4 Super Yang-Mills theory. These operators are constructed from the stress-energy tensor, R-currents, and scalar operators of the theory respectively and can physically be interpreted as detectors. Their correlations can be related to weighted cross sections, which can be calculated perturbatively using amplitudes. In this talk I will describe an efficient way to compute such correlations using superconformal symmetry, which is not only applicable in perturbation theory but can also be extended to the strong coupling regime. Organised by J. Drummond | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8351523280143738, "perplexity": 1986.7993492096668}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-30/segments/1469257827781.76/warc/CC-MAIN-20160723071027-00072-ip-10-185-27-174.ec2.internal.warc.gz"} |
http://en.wikipedia.org/wiki/Bitruncated_cubic_honeycomb | # Bitruncated cubic honeycomb
Bitruncated cubic honeycomb
Type Uniform honeycomb
Schläfli symbol 2t{4,3,4}
t1,2{4,3,4}
Coxeter-Dynkin diagram
Cell type (4.6.6)
Face types square {4}
hexagon {6}
Edge figure isosceles triangle {3}
Vertex figure
(disphenoid tetrahedron)
Space group
Fibrifold notation
Coxeter notation
Im3m (229)
8o:2
[[4,3,4]]
Coxeter group ${\tilde{C}}_3$, [4,3,4]
Dual Oblate tetrahedrille
Disphenoid tetrahedral honeycomb
Properties isogonal, isotoxal, isochoric
The bitruncated cubic honeycomb is a space-filling tessellation (or honeycomb) in Euclidean 3-space made up of truncated octahedra (or, equivalently, bitruncated cubes). It has 4 truncated octahedra around each vertex. Being composed entirely of truncated octahedra, it is cell-transitive. It is also edge-transitive, with 2 hexagons and one square on each edge, and vertex-transitive. It is one of 28 uniform honeycombs.
John Horton Conway calls this honeycomb a truncated octahedrille in his Architectonic and catoptric tessellation list, with its dual called an oblate tetrahedrille, also called a disphenoid tetrahedral honeycomb. Although a regular tetrahedron can not tessellate space alone, this dual has identical disphenoid tetrahedron cells with isosceles triangle faces.
It can be realized as the Voronoi tessellation of the body-centred cubic lattice. Lord Kelvin conjectured that a variant of the bitruncated cubic honeycomb (with curved faces and edges, but the same combinatorial structure) is the optimal soap bubble foam. However, the Weaire–Phelan structure is a less symmetrical, but more efficient, foam of soap bubbles.
## Symmetry
The vertex figure for this honeycomb is a disphenoid tetrahedron, and it is also the Goursat tetrahedron (fundamental domain) for the ${\tilde{A}}_3$ Coxeter group. This honeycomb has four uniform constructions, with the truncated octahedral cells having different Coxeter groups and Wythoff constructions. These uniform symmetries can be represented by coloring differently the cells in each construction.
Five uniform colorings by cell
Space group Im3m (229) Pm3m (221) Fm3m (225) F43m (216) Fd3m (227)
Fibrifold 8o:2 4:2 2:2 1o:2 2+:2
Coxeter group ${\tilde{C}}_3$×2
[[4,3,4]]
=[4[3[4]]]
=
${\tilde{C}}_3$
[4,3,4]
=[2[3[4]]]
=
${\tilde{B}}_3$
[4,31,1]
=<[3[4]]>
=
${\tilde{A}}_3$
[3[4]]
${\tilde{A}}_3$×2
[[3[4]]]
=[[3[4]]]
Coxeter diagram
truncated octahedra 1
1:1
:
2:1:1
::
1:1:1:1
:::
1:1
:
Vertex figure
Vertex
figure
symmetry
[2+,4]
(order 8)
[2]
(order 4)
[ ]
(order 2)
[ ]+
(order 1)
[2]+
(order 2)
Image
Colored by
cell
## Related polyhedra and honeycombs
The regular skew polyhedron {6,4|4} contains the hexagons of this honeycomb.
The [4,3,4], , Coxeter group generates 15 permutations of uniform tessellations, 9 with distinct geometry including the alternated cubic honeycomb. The expanded cubic honeycomb (also known as the runcinated tesseractic honeycomb) is geometrically identical to the cubic honeycomb.
Space
group
Fibrifold Extended
symmetry
Extended
diagram
Order Honeycombs
Pm3m
(221)
4:2 [4,3,4] ×1 1, 2, 3, 4,
5, 6
Fm3m
(225)
2:2 [1+,4,3,4]
↔ [4,31,1]
Half 7, 11, 12, 13
I43m
(217)
4o:2 [[(4,3,4,2+)]] Half × 2 (7),
Fd3m
(227)
2+:2 [[1+,4,3,4,1+]]
↔ [[3[4]]]
Quarter × 2 10,
Im3m
(229)
8o:2 [[4,3,4]] ×2
(1), 8, 9
The [4,31,1], , Coxeter group generates 9 permutations of uniform tessellations, 4 with distinct geometry including the alternated cubic honeycomb.
Space
group
Fibrifold Extended
symmetry
Extended
diagram
Order Honeycombs
Fm3m
(225)
2:2 [4,31,1]
↔ [4,3,4,1+]
×1 1, 2, 3, 4
Fm3m
(225)
2:2 <[1+,4,31,1]>
↔ <[3[4]]>
×2 (1), (3)
Pm3m
(221)
4:2 <[4,31,1]> ×2
5, 6, 7, (6), 9, 10, 11
This honeycomb is one of five distinct uniform honeycombs[1] constructed by the ${\tilde{A}}_3$ Coxeter group. The symmetry can be multiplied by the symmetry of rings in the Coxeter–Dynkin diagrams:
Space
group
Fibrifold Square
symmetry
Extended
symmetry
Extended
diagram
Extended
order
Honeycomb diagrams
F43m
(216)
1o:2 a1 [3[4]] ×1 (None)
Fd3m
(227)
2+:2 p2 [[3[4]]]
×2 3
Fm3m
(225)
2:2 d2 <[3[4]]>
↔ [4,3,31,1]
×2 1, 2
Pm3m
(221)
4:2 d4 [2[3[4]]]
↔ [4,3,4]
×4 4
Im3m
(229)
8o:2 r8 [4[3[4]]]
↔ [[4,3,4]]
×8 5, (*)
### Alternated form
Vertex figure for alternated bitruncated cubic honeycomb, with 4 tetrahedral and 4 icosahedral cells. All edges represent triangles in the honeycomb, but edge-lengths can't be made equal.
This honeycomb can be alternated, creating regular icosahedron from the truncated octahedra with irregular tetrahedral cells created in the gaps. There are three constructions from three related Coxeter-Dynkin diagrams: , , and . These have symmetry [4,3+,4], [4,(31,1)+] and [3[4]]+ respectively. The first and last symmetry can be doubled as [[4,3+,4]] and [[3[4]]]+.
This honeycomb is represented in the boron atoms of the α-rhombihedral crystal. The centers of the icosahedra are located at the fcc positions of the lattice.[2]
Five uniform colorings
Space group I3 (204) Pm3 (200) Fm3 (202) Fd3 (203) F23 (196)
Fibrifold 8−o 4 2 2o+ 1o
Coxeter group [[4,3+,4]] [4,3+,4] [4,(31,1)+] [[3[4]]]+ [3[4]]+
Coxeter diagram
Order double full half quarter
double
quarter
Image
colored by cells
### Projection by folding
The bitruncated cubic honeycomb can be orthogonally projected into the planar truncated square tiling by a geometric folding operation that maps two pairs of mirrors into each other. The projection of the bitruncated cubic honeycomb creating two offset copies of the truncated square tiling vertex arrangement of the plane:
Coxeter
group
${\tilde{A}}_3$ ${\tilde{C}}_2$
Coxeter
diagram
Graph
Bitruncated cubic honeycomb
Truncated square tiling
## Notes
1. ^ [1], A000029 6-1 cases, skipping one with zero marks
2. ^ Williams, 1979, p 199, Figure 5-38.
## References
• John H. Conway, Heidi Burgiel, Chaim Goodman-Strauss, (2008) The Symmetries of Things, ISBN 978-1-56881-220-5 (Chapter 21, Naming the Archimedean and Catalan polyhedra and tilings, Architectonic and Catoptric tessellations, p 292-298, includes all the nonprismatic forms)
• George Olshevsky, Uniform Panoploid Tetracombs, Manuscript (2006) (Complete list of 11 convex uniform tilings, 28 convex uniform honeycombs, and 143 convex uniform tetracombs)
• Branko Grünbaum, Uniform tilings of 3-space. Geombinatorics 4(1994), 49 - 56.
• Kaleidoscopes: Selected Writings of H.S.M. Coxeter, edited by F. Arthur Sherk, Peter McMullen, Anthony C. Thompson, Asia Ivic Weiss, Wiley-Interscience Publication, 1995, ISBN 978-0-471-01003-6 [2]
• (Paper 22) H.S.M. Coxeter, Regular and Semi Regular Polytopes I, [Math. Zeit. 46 (1940) 380-407, MR 2,10] (1.9 Uniform space-fillings)
• A. Andreini, Sulle reti di poliedri regolari e semiregolari e sulle corrispondenti reti correlative (On the regular and semiregular nets of polyhedra and on the corresponding correlative nets), Mem. Società Italiana della Scienze, Ser.3, 14 (1905) 75–129.
• Richard Klitzing, 3D Euclidean Honeycombs, o4x3x4o - batch - O16
• Uniform Honeycombs in 3-Space: 05-Batch
• Williams, Robert (1979). The Geometrical Foundation of Natural Structure: A Source Book of Design. Dover Publications, Inc. ISBN 0-486-23729-X. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 10, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5723336935043335, "perplexity": 18439.87886557864}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1408500830094.68/warc/CC-MAIN-20140820021350-00372-ip-10-180-136-8.ec2.internal.warc.gz"} |
http://planetmath.org/euclideanspaceasamanifold | # Euclidean space as a manifold
Let $\mathbbmss{E}^{n}$ be $n$-dimensional Euclidean space, and let $(\mathbbmss{V},\langle\cdot,\cdot\rangle)$ be the corresponding $n$-dimensional inner product space of translation isometries. Alternatively, we can consider Euclidean space as an inner product space that has forgotten which point is its origin. Forgetting even more information, we have the structure of $\mathbbmss{E}^{n}$ as a differential manifold. We can obtain an atlas with just one coordinate chart, a Cartesian coordinate system $(x^{1},\ldots,x^{n})$ which gives us a bijection between $\mathbbmss{E}^{n}$ and $\mathbbmss{R}^{n}$. The tangent bundle is trivial, with $\operatorname{T}\mathbbmss{E}^{n}\cong\mathbbmss{E}^{n}\times\mathbbmss{V}.$ Equivalently, every tangent space $\operatorname{T}_{p}\mathbbmss{E}^{n},\;p\in\mathbbmss{E}^{n}$. is isomorphic to $\mathbbmss{V}$.
We can retain a bit more structure, and consider $\mathbbmss{E}^{n}$ as a Riemannian manifold by equipping it with the metric tensor
$\displaystyle g$ $\displaystyle=$ $\displaystyle dx^{1}\otimes dx^{1}+\cdots+dx^{n}\otimes dx^{n}$ $\displaystyle=$ $\displaystyle\delta_{ij}dx^{i}\otimes dx^{j}.$
We can also describe $g$ in a coordinate-free fashion as
$g(u,v)=\langle u,v\rangle,\quad u,v\in\mathbbmss{V}.$
## Properties
1. 1.
Geodesics are straight lines in $\mathbbmss{R}^{n}$.
2. 2.
The Christoffel symbols vanish identically.
3. 3.
The Riemann curvature tensor vanish identically.
Conversely, we can characterize Eucldiean space as a connected, complete Riemannian manifold with vanishing curvature and trivial fundamental group.
Title Euclidean space as a manifold EuclideanSpaceAsAManifold 2013-03-22 15:29:48 2013-03-22 15:29:48 matte (1858) matte (1858) 9 matte (1858) Definition msc 53B21 msc 53B20 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 20, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9939942955970764, "perplexity": 455.57514287471133}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257647600.49/warc/CC-MAIN-20180321082653-20180321102653-00783.warc.gz"} |
https://brilliant.org/practice/translation/ | Geometry
# Translation
Point $$(2, 1)$$ is moved to point $$(10,11)$$ by $T: (x, y) \rightarrow (x+a, y+b).$ What is $$a+b$$?
If we translate the point $$(9, 3)$$ by $$(13, 2),$$ what would be the new point?
The curve $$y=2x^2+3x-9$$ undergoes a parallel translation by $$7$$ units in the positive direction of the $$x$$-axis and $$-3$$ units in the positive direction of the $$y$$-axis. If the equation of the resulting curve is $$y=ax^2+bx+c,$$ what is $$a+b+c?$$
Consider a translation of axes $T: (x, y) \to (x+a, y+b)$ such that the coordinates of a point $$P=(7, 4)$$ with respect to the new system of coordinates after translation are $$P'=(10,-11).$$ What is the value of $$a+b?$$
If the point $$(m,n)$$ is shifted by $$6$$ in the positive $$x$$ direction and by $$-12$$ in the positive $$y$$ direction, then it coincides with the center of the circle $x^2+y^2-6x+2y-13=0.$ What is the value of $$m+n?$$
× | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8103324174880981, "perplexity": 60.52425101769519}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-04/segments/1547583700734.43/warc/CC-MAIN-20190120062400-20190120084400-00448.warc.gz"} |
http://st-hadoop.cs.umn.edu/getting-started/spatio-temporal-range-query | # Spatio-temporal Range Query
### Extensible operations
Operations in ST-Hadoop are implemented as regular MapReduce programs. The main difference between spatio-temporal operations and spatial operations shipped with SpatialHadoop is that the input file is spatiotemporally indexed. To read a spatio-temporal indexed file, you need to provide the correct ShapeFormat that represent an extension of STPoint. Besides, the regular map and reduce functions, ST-Hadoop allows you to provide a filter function that performs and early pruning step that prunes away file blocks that do not contribute to the final answer based on two property their minimal bounding rectangles (MBRs) and their slicing time span (interval). In this tutorial, you will learn how to use built-in spatio-temporal range query and a step by step instructions on how to write your own spatio-temporal operation.
### Spatio-temporal Range Query:
The basic operation of spatio-temporal data is the range query. The range query contains a set of shapes, a rectangular query area (A), and an interval of the query time range (T). The output is all shapes that overlap with the query area (A) and time interval (T).
To use spatio-temporal range query you can execute the following command line.
./hadoop jar st-hadoop-uber.jar strangequery
/indexDir/ /Result
rect:x1,y1,x2,y2 interval:t1,t2
shape:edu.umn.cs.sthadoop.core.STPoint -overwrite
Parameters and Command Description strangequery This is the map reduce method that invokes the spatio-temporal range query. indexDir The HDFS directory where the dataset is being indexed. The directory represent the parent directory of the hierarchy spatio-temporal index Result The HDFS output directory where the result will be stored. rect: The spatial minimum boundary rectangle area of the spatio-temporal range query. interval: The time interval of the spatio-temporal range query. The time should be in the following standard time format: yyyy-MM-dd, such as 2017-01-12. shape: The shape format of should be extended from STPoint that support spatio-temporal data. time: * Optional parameters to intentionally specify a specific resolution layer to query from. For example, if space partitioning technique used in spatio-temporal index then these possible parameters could be passed [ day, week, month, year] If property not specified in the execution command line, then ST-Hadoop will decide the execution plan considering all spatio-temporal resolution indices. -overwrite This flag indicate to overwrite the output directory if it existed.
## Contact
We appreciate communicating your feedback, comments, and problems reporting through the email | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.30212903022766113, "perplexity": 4038.4724302488003}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676589270.3/warc/CC-MAIN-20180716115452-20180716135452-00364.warc.gz"} |
https://www.vedantu.com/question-answer/two-coherent-monochromatic-light-beams-of-class-12-physics-cbse-5f5d32f98f2fe24918455b02 | Question
# Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible resulting intensities are :A. 5I and 0B. 5I and 3IC. 9I and ID. 9I and 3I
Hint: Take ${{I}_{1}}$ and ${{I}_{2}}$ as the two intensities of two coherent monochromatic light beams, then find out the maximum and minimum intensity by constructing a formula with the help of those two assumed variable.
If ${{I}_{1}}$ and ${{I}_{2}}$ are two intensities of two coherent monochromatic light beams, then
${{I}_{\max }}$=($\sqrt{{I_1}}$ + $\sqrt{{I_2}}$)$^{2}$
${{I}_{\min }}$=($\sqrt{{I_1}}$ - $\sqrt{{I_2}}$)$^{2}$
Now substituting the value of ${{I}_{1}}$ and ${{I}_{2}}$ with I and 4I,
Therefore, maximum intensity
${{I}_{\max }}$=($\sqrt{I}$+$\sqrt{4I}$)$^{2}$
On solving it comes,
${{I}_{\max }}$=9I
Therefore, minimum intensity,
${{I}_{\min }}$=($\sqrt{I}$-$\sqrt{4I}$) $^{2}$
On solving it comes,
${{I}_{\min }}$=I
Therefore,
Option C is the correct option.
Maximum intensity is =($\sqrt{I}$+$\sqrt{4I}$)$^{2}$
Minimum intensity is=($\sqrt{I}$-$\sqrt{4I}$)$^{2}$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9083420634269714, "perplexity": 2009.5292218204038}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178357641.32/warc/CC-MAIN-20210226115116-20210226145116-00634.warc.gz"} |
https://tolstoy.newcastle.edu.au/R/help/06/08/33538.html | # Re: [R] covariance matrix of predictions
From: Ritwik Sinha <ritwik.sinha_at_gmail.com>
Date: Mon 28 Aug 2006 - 08:54:05 EST
Hi,
If I understand correctly the
Var(X \hat{\beta}) = X (X'X)^{-1}X' \sigma^2, where X will now be "x.pred".
Which should be easily obtained by performing the matrix computation and multiplying it with the estimate of the variance.
For more details about different aspects of the estimate and variance of the predictor refer to page 39 of http://www.stat.lsa.umich.edu/~faraway/book/
Ritwik Sinha
On 8/23/06, Arnab mukherji <[email protected]> wrote:
>
> Hi !
>
> I am trying to get at the covariance of the predictions of a linear model.
> Suppose the we have:
>
> > x<-runif(1000)
> > y<-2 + 25x*x +rnorm(1000)
> > lm1 <-lm(y~x, data = data.frame(y = y, x=x))
> > x.pred <-runif(10)
> > y.hat <- predict(lm1, newdata = data.frame(x=x.pred))
>
> I was wondering how to get an estimate of the covariance of y.hat which
> would be a 10 x 10 matrix telling be the uncertainty in each of the
> predictions.
>
> thanks
>
> Arnab
>
> ______________________________________________
> [email protected] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
Ritwik Sinha
Epidemiology and Biostatistics
Case Western Reserve University
http://darwin.cwru.edu/~rsinha
[[alternative HTML version deleted]]
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https://www.physicsforums.com/threads/using-remainder-theorem-to-find-remainder.900226/ | # Using Remainder Theorem to find remainder
Tags:
1. Jan 13, 2017
### Schaus
1. The problem statement, all variables and given/known data
(y4 - 5y2 + 2y - 15) / (3y - √(2))
The answer says (2√(2)/3)-(1301/81)
2. Relevant equations
3. The attempt at a solution
Using synthetic division
3y - √(2) = 0
3y = √(2)
y = √(2)/3
View attachment 111547
My final answer that I keep getting is (2√(2)/3)-21. I can't seem to get (2√(2)/3)-(1301/81). I was just wondering if someone could show me where I'm going wrong? Sorry writing this out was very difficult so I hope you can still understand it.
Last edited: Jan 13, 2017
2. Jan 13, 2017
### Staff: Mentor
I don't actually can follow your calculations. If I compare my calculation with your result, then I think you simply lost some denominators.
I get $\frac{4}{81}-\frac{10}{9}-15+\frac{2\sqrt{2}}{3}$ whereas you seem to have added only the nominators $4-10-15+\frac{2\sqrt{2}}{3}$.
I once gave an example on PF here:
https://www.physicsforums.com/threa...r-a-polynomial-over-z-z3.889140/#post-5595083
Maybe it helps.
3. Jan 13, 2017
### Schaus
Sorry, I should have just posted this to begin with.
4. Jan 13, 2017
### Ray Vickson
Your long-division process is all wrong. Let $p(y) = y^4 - 5y^2 + 2y - 15$ and $d(y) = 3y - \sqrt{2}$. You want to find a "quotient" $q(y)$ and a number $r$ (the "remainder") that give you $p(y) = q(y) d(y) + r.$ The question is asking you to find $r$.
Step 1: see how many times the leading term of $d(y)$ will go into the leading term of $p(y)$; that is the number of times $3y$ goes into $y^4$. The answer in this case is $y^4/(3y) = (1/3)y^3$, so that is the first term in your quotient $q(y)$. Now we have
$$p(y) - \frac{1}{3} y^3 d(y) = \frac{\sqrt{2}}{3} y^3 -5 y^2 + 2y - 15 \equiv p_1(y).$$
However, all that would be doing it the hard way. The easy way would be to go ahead and use the "remainder theorem".
Step 2: see how many times the leading term of $d(y)$ goes into the leading term of $p_1(y)$. The answer is $(\sqrt{2}/3)/(3 y) = (\sqrt{2}/9) y^2$, so that is the next term in your quotient $q(y)$. We have
$$p_2(y) \equiv p_1(y) - \frac{\sqrt{2}}{9} y^2 d(y) = -\frac{43}{9} y^2 + 2y - 15.$$
So, up to now we have
$$p(y) = \left( \frac{1}{3} y^3 + \frac{\sqrt{2}}{9} y^2 \right) d(y) + p_2(y).$$
Keep going like that; the next term in the quotient $q(y)$ will be the number of times the leading term of $d(y)$ goes into the leading term of $p_2(y)$, so is the number of times $3y$ goes into $-(43/9) y^2$, etc., etc.
The remainder will be what you have left when the process comes to an end.
However, all that would be doing it the hard way; I included the material just because you attempted to do it, but did it all wrong. The easy way would be to just use the so-called "remainder theorem".
5. Jan 14, 2017
### Schaus
I was using synthetic division which worked on every other question but I'll try it the way you're suggesting it.
6. Jan 14, 2017
### Schaus
I got the same result as the answer. Thanks for your help!
7. Jan 14, 2017
### PetSounds
It looks to me like you simply made a couple multiplication errors when working with fractions. I worked the problem with synthetic division and got the right answer.
Last edited: Jan 14, 2017
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https://www.ias.ac.in/listing/bibliography/jess/K._Krishnamoorthy | • K Krishnamoorthy
Articles written in Journal of Earth System Science
• Detection of marine aerosols with IRS P4-Ocean Colour Monitor
The atmospheric correction bands 7 and 8 (765nm and 865nm respectively) of the Indian Remote Sensing Satellite IRS P4-0CM (Ocean Colour Monitor) can be used for deriving aerosol optical depth (AOD) over the oceans. A retrieval algorithm has been developed which computes the AOD using band 7 data by treating the ocean surface as a dark background after removing the Rayleigh path radiance in the sensor-detected radiances. This algorithm has been used to detect marine aerosol distributions at different coastal and offshore locations around India.
A comparison between OCM derived AOD and the NOAA operational AOD shows a correlation ∼0.92 while that between OCM derived AOD and the ground-based sun photometer measurements near the coast of Trivandrum shows a correlation of ∼0.90.
• Performance of WRF-Chem over Indian region: Comparison with measurements
The aerosol mass concentrations over several Indian regions have been simulated using the online chemistry transport model, WRF-Chem, for two distinct seasons of 2011, representing the pre-monsoon (May) and post-monsoon (October) periods during the Indo–US joint experiment ‘Ganges Valley Aerosol Experiment (GVAX)’. The simulated values were compared with concurrent measurements. It is found that the model systematically underestimates near-surface BC mass concentrations as well as columnar Aerosol Optical Depths (AODs) from the measurements. Examining this in the light of the model-simulated meteorological parameters, we notice the model overestimates both planetary boundary layer height (PBLH) and surface wind speeds, leading to deeper mixing and dispersion and hence lower surface concentrations of aerosols. Shortcoming in simulating rainfall pattern also has an impact through the scavenging effect. It also appears that the columnar AODs are influenced by the unrealistic emission scenarios in the model. Comparison with vertical profiles of BC obtained from aircraft-based measurements also shows a systematic underestimation by the model at all levels. It is seen that concentration of other aerosols, viz., dust and sea-salt are closely linked with meteorological conditions prevailing over the region. Dust is higher during pre-monsoon periods due to the prevalence of north-westerly winds that advect dust from deserts of west Asia into the Indo-Gangetic plain. Winds and rainfall influence sea-salt concentrations. Thus, the unrealistic simulation of wind and rainfall leads to model simulated dust and sea-salt also to deviate from the real values; which together with BC also causes underperformance of the model with regard to columnar AOD. It appears that for better simulations of aerosols over Indian region, the model needs an improvement in the simulation of the meteorology.
• # Journal of Earth System Science
Current Issue
Volume 128 | Issue 8
December 2019
• # Editorial Note on Continuous Article Publication
Posted on July 25, 2019 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8176025152206421, "perplexity": 6526.560132890908}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575541317967.94/warc/CC-MAIN-20191216041840-20191216065840-00504.warc.gz"} |
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https://www.nonlin-processes-geophys.net/26/1/2019/ | Journal cover Journal topic
Nonlinear Processes in Geophysics An interactive open-access journal of the European Geosciences Union
Journal topic
Nonlin. Processes Geophys., 26, 1–12, 2019
https://doi.org/10.5194/npg-26-1-2019
Nonlin. Processes Geophys., 26, 1–12, 2019
https://doi.org/10.5194/npg-26-1-2019
Research article 18 Feb 2019
Research article | 18 Feb 2019
# Exploring the sensitivity of Northern Hemisphere atmospheric circulation to different surface temperature forcing using a statistical–dynamical atmospheric model
Exploring the sensitivity of Northern Hemisphere atmospheric circulation to different surface temperature forcing using a statistical–dynamical atmospheric model
Sonja Totz1,2, Stefan Petri1, Jascha Lehmann1, Erik Peukert1,2, and Dim Coumou1,3 Sonja Totz et al.
• 1Potsdam Institute for Climate Impact Research (PIK), Leibniz Association, Potsdam, Germany
• 2Department of Physics, University of Potsdam, Potsdam, Germany
• 3Institute for Environmental Studies (IVM), Vrije University Amsterdam, Amsterdam, the Netherlands
Correspondence: Sonja Totz ([email protected])
Abstract
Climate and weather conditions in the mid-latitudes are strongly driven by the large-scale atmosphere circulation. Observational data indicate that important components of the large-scale circulation have changed in recent decades, including the strength and the width of the Hadley cell, jets, storm tracks and planetary waves.
Here, we use a new statistical–dynamical atmosphere model (SDAM) to test the individual sensitivities of the large-scale atmospheric circulation to changes in the zonal temperature gradient, meridional temperature gradient and global-mean temperature. We analyze the Northern Hemisphere Hadley circulation, jet streams, storm tracks and planetary waves by systematically altering the zonal temperature asymmetry, the meridional temperature gradient and the global-mean temperature. Our results show that the strength of the Hadley cell, storm tracks and jet streams depend, in terms of relative changes, almost linearly on both the global-mean temperature and the meridional temperature gradient, whereas the zonal temperature asymmetry has little or no influence. The magnitude of planetary waves is affected by all three temperature components, as expected from theoretical dynamical considerations. The width of the Hadley cell behaves nonlinearly with respect to all three temperature components in the SDAM. Moreover, some of these observed large-scale atmospheric changes are expected from dynamical equations and are therefore an important part of model validation.
1 Introduction
Large-scale atmosphere dynamics including Hadley cells, jet streams, storm tracks and planetary waves play a key role in the general circulation of the atmosphere, determining climatic conditions worldwide. There is emerging evidence that these large-scale dynamics have significantly changed in recent observations and/or might do so in climate change projections of the 21st century.
Hadley cells are large-scale atmospheric circulations in the tropics and are responsible for the transport of heat and moisture from the Equator to the mid-latitudes (D'Agostino and Lionello, 2016). Recent literature suggests that the Hadley cells have widened in the past few decades due to ozone depletion in the Southern Hemisphere (Kang et al., 2011; Son et al., 2009) and due to increases in different warming agents as carbon dioxide and tropospheric ozone in the Northern Hemisphere (Allen et al., 2012). Further possible drivers of the Hadley cell dynamics are sea surface temperature (SST) variations, which may lead to tropical contraction (Allen et al., 2014), stratospheric cooling, global warming or changes in baroclinic eddy phase speeds (Chen et al., 2014). While most studies based on reanalysis products observe that, together with this widening, there is also a strengthening of the Hadley cells (Nguyen et al., 2013), and modeling studies project a weakening over the 21st century under a high-emission scenario (Lu et al., 2007). This discrepancy may be explained by relatively short observational records, large natural variability or model deficiencies (Allen et al., 2014).
Changes in the strength and the width of the Hadley cell circulation have strong implications for a variety of atmospheric phenomena such as jet streams, extratropical storms and planetary waves.
Jet streams are upper-level fast currents of westerly winds that circulate around the hemisphere. The jet stream is caused by momentum conservation, when air of the Hadley cell moves poleward, and by meridional contrasts in solar heating (Woollings, 2010). Therefore, changes in the Hadley cell directly influence the jet. Storm tracks are associated with fast-traveling Rossby waves that move from west to east, which drive the jet stream (Totz et al., 2018). Under climate change, a weakening of the northern subtropical jet stream in winter is observed by most studies (Molnos et al., 2017; Rikus, 2015), though a few studies also observe a strengthening trend (Pena-Ortiz et al., 2013). The underlying drivers of those changes are still debated. One possible driver is the Arctic amplification leading to a decreasing meridional temperature gradient and a weakening of the jet stream and storm tracks.
Storm tracks play a crucial role in modulating precipitation in the Earth system (Hawcroft et al., 2012; Lehmann and Coumou, 2015; Raible et al., 2007). Yin (2005) studied storm tracks under climate change using 15 coupled climate models and found that storm tracks shift poleward and intensify under climate change in winter. In addition, O'Gorman (2010) discovered that the storm track intensity is nonlinearly related to global warming. Coumou et al. (2015) show that during the satellite period (1979–2013) storm tracks have significantly weakened in boreal summer. They argue that the weakening might be related to a decreasing meridional temperature gradient. Consistently, models of the Coupled Model Intercomparison Project Phase 5 (CMIP5) project a further decrease in summer storm track activity under a high-emission scenario until the end of the 21st century (Lehmann et al., 2014).
In contrast to the changes in these large-scale circulation components, a recent study by Barnes and Polvani (2013) indicates that there are no significant trends in the strength of long-term quasi-stationary planetary waves under climate change.
Planetary waves are disturbances of longer timescales (beyond 15 days) and are manifested by a displacement of the circumpolar flow out of zonal symmetry, as is apparent at high latitude. They lead to a gradual undulation of the jet stream about latitude circles (Salby, 2012). These planetary waves strongly interact with storm tracks in the mid-latitudes and impact their location and activity (Branstator, 1994; Hoskins and Valdes, 1990). The barotropic component of the planetary waves especially has a strong influence on the storm tracks and can change the distribution of storms by steering the disturbances (Branstator, 1994).
The large-scale atmospheric circulation is mainly a result of large-scale temperature differences between the Equator and the poles and between the ocean and land. A further key driver is the angular momentum as shown by the study of Egger et al. (2007) Different modeling studies have thus tried to examine the influences of different temperature sources on changes in mid-latitude circulation. Using an idealized general circulation model (GCM), Butler et al. (2010) separate the temperature effects by using different heating sources. Their main findings are that a warming tropical troposphere causes poleward shifts in the extratropical tropospheric storm tracks and a weakened stratospheric Brewer–Dobson circulation; a polar stratosphere cooling leads also to a shift of the extratropical storm tracks, and a warming at the polar surface results in a equatorward shift of the storm tracks. With their approach Butler et al. (2010) can attribute which forcing has the most important influence on the shift of jet streams, storm tracks, etc. In a study from 2011, Butler et al. (2011) presented an alternative perspective on the response of the mid-latitude tropospheric circulation to zonal-mean tropical heating. The projection of the heating onto the isentropic surfaces at extratropical latitudes drives the poleward shift in wave generation at lower levels. In addition, the poleward shift in the heat fluxes within the troposphere and the diffusive nature of eddy fluxes of the polar vortex lead to a poleward shift in wave breaking near the tropopause.
However, none of the studies mentioned above analyzed the impact of zonal temperature asymmetry and the meridional temperature gradient as well as global-mean temperature by changing the temperature components directly without adding a heat source or increasing CO2. For that reason, changes in the Hadley cell, jet streams, planetary waves and storm tracks might not be directly assigned to individual temperature components.
In this study, we analyze the full temperature space with a novel systematic approach using a statistical–dynamical atmospheric model (SDAM; Totz et al., 2018). This way we can scan for “nonlinearities” in the system (i.e., the Hadley cell edge – HCE – might only be very sensitive to meridional temperature gradients for a narrow range of meridional temperature gradient values, and outside of that range it is not sensitive). It is important to know such nonlinearities, as these could imply more abrupt changes under global warming.
The statistical–dynamical atmospheric model Aeolus 1.0 (Totz et al., 2018) is explained in Sect. 2 in more detail. In Sect. 3, we describe the data used for the experiments, the separation of the temperature components and the analyzed dynamical variables. In Sect. 4 we present the results, and in Sect. 5, we compare them with the literature. In Sect. 6 we provide a short discussion on the robustness and an interpretation of our results. We conclude with a summary in Sect. 7.
2 Model description
The experiments are run with the statistical–dynamical atmospheric model Aeolus 1.0 (Coumou et al., 2011; Totz et al., 2018). It is a model with 2.5 dimensions, with the vertical dimension coarsely resolved, therefore belonging to the model class of intermediate complexity atmosphere models (Claussen et al., 2002; Petoukhov et al., 2000). Aeolus is based on time-averaged (over short timescales) equations in which transient eddies are parameterized in terms of the large-scale field (Peixoto and Oort, 1992; Saltzman, 1978). This means that instead of solving every eddy directly, only the ensemble mean eddy characteristics (in terms of heat, water vapor and momentum transport) are solved. The essential difference compared to more widely used GCMs is thus the point of truncation in the frequency spectrum of atmospheric motion (Saltzman, 1978). This different approach allows for much coarser spatial and temporal discretization, making SDAMs computationally efficient, because the synoptic waves are parameterized in terms of the large-scale wind field which is the basic idea of a statistical–dynamical method. The model includes the two-way dynamical interactions between parameterized storms and resolved westerlies. A full description can be found in Coumou et al. (2011).
The model has five vertical levels in the troposphere, with the model top at 10 000 m altitude. Aeolus 1.0 has a “dummy” stratosphere (i.e., its physics and dynamics are not resolved) in order to have a boundary condition at the top of the troposphere. In this experiment we excluded topographic influences, and it is an atmosphere-only setup using prescribed sea level temperatures.
Aeolus 1.0 contains a full hydrological cycle consisting of three-layer stratiform cloud plus convective cloud scheme, as presented and validated in Eliseev et al. (2013). The convective plus three-layer stratiform cloud scheme includes low-level, mid-level and upper-level stratiform clouds. The equation for humidity is a prognostic equation and is described in Petoukhov et al. (2000).
Parameter values for the dynamical core were taken from the calibration process, as described in Totz et al. (2018), which optimizes the model's representation of the tropospheric large-scale circulation.
For more information, such as comparisons of Aeolus 1.0 with GCMs or the equations for planetary waves, zonal-mean meridional and zonal-mean velocities as well as the azonal wind velocities, we refer the reader to Totz et al. (2018).
3 Data and methods
## 3.1 Aeolus forcing parameters
The simulations are forced by climatological (1979–2014) winter mean (December–January–February: DJF) data of SST and specific humidity at the surface, using ERA-Interim data from the European Centre for Medium-Range Weather Forecasts (ECMWF; Dee et al., 2011). First, the data are regridded to $\mathrm{3.75}{}^{\circ }×\mathrm{3.75}{}^{\circ }$ (longitude×latitude). In this experiment, atmospheric temperatures extrapolated to sea level and humidity are prescribed to decouple the dynamics from diabatic heating and associated temperature changes. This way, the dynamical core equilibrates the prescribed temperature and humidity patterns without any additional complicating factors.
In the Aeolus stand-alone mode, the output is on the same time step as the input, i.e., seasonal means. However, internally, the time stepping of the solver is in 1 h resolution. In Aeolus, the synoptic wind fields u and v are parameterized in terms of the large-scale long-term fields (i.e., the seasonal mean fields). Detailed information is provided in Coumou et al. (2011).
We then test how different changes in the temperature profiles affect different aspects of the circulation. We do thousands of individual simulations to disentangle and separately analyze the effect of the global-mean temperature, Equator-to-pole temperature gradient and east–west temperature differences.
## 3.2 Specifications of the surface temperature
In this and the following sections, the angle brackets denote time-averaged quantities, the overline denotes zonal-mean quantities, the prime indicates synoptic scale components (2–6-day period), and the star indicates azonal components, i.e., deviations from the zonal mean.
Figure 1Schematic illustration of the temperature perturbations.
For the sensitivity analysis we vary three different temperature components: (1) the meridional temperature gradient $\frac{\mathrm{d}T}{\mathrm{d}\mathit{\varphi }}$, (2) the zonal temperature asymmetry T* (i.e., deviations from the zonal mean) and (3) the global-mean temperature Tglobal.
We change the temperature for each grid cell for the three components in three steps. First, the parameter ${w}_{{T}_{\mathit{\varphi }}}$ is used to vary the meridional temperature gradient by cooling and/or warming the poles:
$\begin{array}{}\text{(1)}& {T}_{\mathrm{1}}\left(\mathit{\varphi },\mathit{\lambda }\right)={T}_{\mathrm{EQ}}\left(\mathit{\lambda }\right)+\left({T}_{\mathrm{DJF}}\left(\mathit{\varphi },\mathit{\lambda }\right)-{T}_{\mathrm{EQ}}\left(\mathit{\lambda }\right)\right)\cdot {w}_{{T}_{\mathit{\varphi }}},\end{array}$
whereby ϕ and λ are respectively latitude and longitude, TDJF(ϕ,λ) is the original temperature, TEQ(λ) is the temperature at the Equator, and T1(ϕ,λ) is the altered temperature. In temperature T1 only the meridional temperature gradient is altered or updated, and the temperature change in the azonal component as well as the global-mean temperature are updated in the next steps. The parameter ${w}_{{T}_{\mathit{\varphi }}}$ is varied between 0.75 and 1.1 (with steps of 0.025) to examine the behavior of the dynamical core under conditions between −25 % to +10 % of their present-day wintertime climatological values.
In the second step the global-mean temperature is adapted to the original global-mean temperature TDJF, and global-mean temperature is varied by the parameter Tglobal:
$\begin{array}{ll}{T}_{\mathrm{2}}\left(\mathit{\varphi },\mathit{\lambda }\right)& ={T}_{\mathrm{1}}\left(\mathit{\varphi },\mathit{\lambda }\right)-\left(\mathrm{Mean}\left({T}_{\mathrm{1}}\right)-\mathrm{Mean}\left({T}_{\mathrm{DJF}}\right)\right)\\ \text{(2)}& & +{T}_{\mathrm{global}},\end{array}$
whereby Mean(T1) is the global-mean temperature of T1, and Mean(TDJF) is the global-mean temperature of TDJF.
In the third step, the parameter wazonal is used to alter the azonal temperature, which is added to the zonal-mean temperature $\stackrel{\mathrm{‾}}{{T}_{\mathrm{1}}}$:
$\begin{array}{}\text{(3)}& {T}_{\mathrm{Final}}\left(\mathit{\varphi },\mathit{\lambda }\right)={T}_{\mathrm{2}}^{*}\left(\mathit{\varphi },\mathit{\lambda }\right)\cdot {w}_{\mathrm{azonal}}+\stackrel{\mathrm{‾}}{{T}_{\mathrm{2}}}\left(\mathit{\varphi }\right).\end{array}$
This way ${w}_{{T}_{\mathit{\varphi }}}=\mathrm{1}$, wazonal=1 and Tglobal=0 indicate present-day conditions. The temperature perturbation TFinal is the final temperature based on all three temperature components and is used as model input that the dynamical core equilibrates. The temperature perturbations are applied at sea level and propagate to the upper levels based on the lapse rate equation. A schematic plot of the different temperature perturbations is shown in Fig. 1.
Also the parameter wazonal is varied between 0.75 and 1.1 (with steps of 0.025). These limits roughly correspond to expected temperature gradients during the last glacial maximum scenario and in a 2×CO2 scenario (Coumou et al., 2011). Large zonal temperature differences, i.e., large values of wazonal, imply strong temperature deviations between land masses and oceans. Small $\frac{\mathrm{d}T}{\mathrm{d}\mathit{\varphi }}$ values represent amplified warming of the poles, compared to the Equator, and thus a reduced meridional temperature gradient.
The parameter Tglobal is altered between −4 and +4 K (with steps of 4 K) relative to the climatological present-day (PD) temperature (1979–2014). This range covers climate variability over the past million years and possible near-future changes.
For each temperature component, we determine its influence on the strength and its width of the Hadley cell as well as the strength of zonal-mean jets, storm tracks and planetary waves in the Northern Hemisphere.
Since the changes for the zonal temperature asymmetry and the meridional temperature gradients are relative, it can be that in terms of absolute values the zonal temperature asymmetry is greater than that of the meridional temperature gradient.
To force the Aeolus dynamical core, we use perturbed surface temperature profiles derived from the ERA-Interim winter climatology as explained above. We performed 2025 simulations with a regular 3-D parameter space using the multi-run simulation environment SimEnv, which provides a tool to inspect the model's behavior in the parameter space by discrete numerical sampling (Flechsig et al., 2013).
## 3.3 Dynamical variables
To obtain the strength of the jet stream for this analysis, we use seasonally (DJF) averaged zonal mean and vertical averaged zonal wind $\stackrel{\mathrm{‾}}{〈u〉}$ from 3000 to 9000 m (corresponding to 200 to 700 mbar). For simplicity, we define the jet stream strength as the maximum of $\stackrel{\mathrm{‾}}{〈u〉}$ between 10 and 80 N of the vertical averaged wind velocity.
We define the strength of the Hadley cell as the maximum of the meridional mass stream function integrated between 200–700 mbar, as well as between 0 and 90 latitude, and the width as the distance between the mass flux zero crossings near the 0 and 30 latitude.
As a measure of storm track activity we calculate the eddy kinetic energy $\left({E}_{\mathrm{K}}^{\prime }=\mathrm{0.5}\left({{u}^{\prime }}^{\mathrm{2}}±{{v}^{\prime }}^{\mathrm{2}}\right)\right)$ , whereby uand v are the zonal and meridional synoptic wind velocity. We average the eddy kinetic energy over all five pressure levels and calculate the maximum between 10 and 80 N to analyze the strength and shift of the storm track activity.
We calculate the strength of the planetary waves by averaging all positive values between 20–80 N of the azonal wind components u* and v*.
4 Results
We compare and analyze the zonal-mean dynamical variables of eddy kinetic energy $\stackrel{\mathrm{‾}}{〈{E}_{\mathrm{K}}^{\prime }〉}$ (which captures storm track activity), zonal-mean zonal wind velocity $\stackrel{\mathrm{‾}}{〈u〉}$ and the vertical integral of the lower tropospheric integrated mass flux $\stackrel{\mathrm{‾}}{〈m〉}$ as well as azonal wind velocities u* and v*.
## 4.1 Tropical circulation
### 4.1.1 Strength and width of the Hadley cell
The integrated mass flux in the lower troposphere of the present-day modeled climatological Northern Hemisphere (NH) winter values (black line in Fig. 2) captures the shape of the red curve well from ERA-Interim data. In particular, the maximum strength, defined as the minimum between the zero crossings, is close to the ERA-Interim data. Bigger differences exist in the SH. This model bias might be related to the missing Antarctic ice sheet, upper-tropospheric ozone, the constant lapse rate assumption or fundamental limitations of the equations. Another reason could be due to the statistical nature of the eddy representation in the SDAM, since the summer Hadley cell (HC) is dominated by eddy momentum flux divergence (Schneider and Bordoni, 2008).
Figure 2Integrated meridional mass stream function in the lower troposphere. The black line indicates model output for ${w}_{{T}_{\mathit{\varphi }}}=\mathrm{1}$ and wazonal=1, and the red line indicates the ERA-Interim climatological boreal winter data.
Zero-crossing refers to the point in the graph where the function f(x) crosses the y=0 line. The modeled Hadley cell's width, defined as the distance between the mass flux zero crossings near the 0 and 30 latitude, is smaller than in ERA Interim.
For further analysis we plot the width (Fig. 3) and strength (Fig. 4) of the Hadley cell as a function of ${w}_{{T}_{\mathit{\varphi }}}$, wazonal and ΔTG,PD, whereby ΔTG,PD is the difference between the present-day global-mean temperature and the altered global-mean temperature. In general, both a stronger meridional temperature gradient and a stronger zonal temperature contrast lead to a nonlinear broadening of the Hadley cell width; for meridional temperature gradients smaller than the present day, the width is smaller for larger global-mean temperature. The Hadley cell expands for a stronger meridional temperature gradient and even for a greater zonal temperature asymmetry as well, but it expands with a smaller rate.
Figure 3Width of the Hadley cell in relation to ${w}_{{T}_{\mathit{\varphi }}}$ and wazonal and ΔTG,PD, whereby ΔTG,PD is the difference between the present-day temperature and the altered global-mean temperature in boreal winter.
For meridional temperature gradients larger than the present day, the influence of the global-mean temperature and meridional temperature gradient are less significant, and the values of the zonal temperature asymmetry play a bigger role. In this case larger values of the zonal temperature asymmetry lead to a larger width of the Hadley cell. However, depending on the global-mean temperature an increase of the zonal temperature asymmetry can also lead to a decrease of the Hadley cell width, e.g., $\mathrm{\Delta }{T}_{\mathrm{G},\mathrm{PD}}\ge \mathrm{3}$, $\mathrm{0.95}\ge {w}_{{T}_{\mathit{\varphi }}}\ge \mathrm{0.9}$ and wazonal≥0.85.
The Hadley cell width shows larger changes in response to changes in the meridional temperature gradient than for changes in the zonal temperature asymmetry, indicating that the former has a stronger relative influence.
Figure 4Strength of the Hadley cell in relation to ${w}_{{T}_{\mathit{\varphi }}}$ and wazonal and ΔTG,PD. The arrow points in the direction of the strongest gradient in boreal winter.
The Hadley cell strengthens with an increasing meridional gradient and depends more strongly on global-mean temperature than on wazonal (Fig. 4).
## 4.2 Extratropical circulation
### 4.2.1 Strength of the jet stream
The jet stream locations and strengths for both hemispheres are detectable as two distinct maxima in the zonal-mean zonal wind velocity in ERA Interim (Fig. 5a). Aeolus reasonably reproduces the main jet stream features in terms of spatial position and magnitude (Fig. 5c). The modeled magnitude of the jet in the Northern Hemisphere is in better agreement with reanalysis data than in the Southern Hemisphere. This is likely related to the fact that Aeolus is not coupled to an ice model, thus effects of the Antarctic ice sheet are not considered. The model reasonably reproduces near-surface tropical easterlies (“trade winds”) at low latitudes.
Figure 5b and d show the impact of changes in the meridional temperature gradient $\frac{\mathrm{d}T}{\mathrm{d}\mathit{\varphi }}$ on jet stream dynamics. With a higher meridional temperature gradient, the strength of the jet stream increases and with a lower temperature gradient, the strength decreases. For present-day climatology values, the jet stream strength is about 25 m s−1 in the Northern Hemisphere. For a decrease of 10 % of the temperature gradient the velocity weakens to 20 m s−1. With an increase of 10 % of the meridional temperature, the jet stream velocity is more than 30 m s−1, and with 10 %, it is stronger in the Northern Hemisphere.
Figure 5Zonal mean zonal wind velocity $\stackrel{\mathrm{‾}}{〈u〉}$ representing the jet streams in boreal winter. Panel (a) shows ERA-Interim data, and the others show results from Aeolus with different ${w}_{{T}_{\mathit{\varphi }}}$. In (b)${w}_{{T}_{\mathit{\varphi }}}=\mathrm{0.75}$, in (c)${w}_{{T}_{\mathit{\varphi }}}=\mathrm{1.0}$ and in (d)${w}_{{T}_{\mathit{\varphi }}}=\mathrm{1.1}$. All other parameters are set to standard values.
This is also observed in Fig. 6, where the jet stream strength is shown as function of ${w}_{{T}_{\mathit{\varphi }}}$, wazonal and ΔTG,PD.
The strength of the jet stream is sensitive to the meridional temperature gradient and to the global-mean temperature. The zonal temperature contrasts have little influence on the jet stream strength.
Figure 6Jet stream strength defined by the maximum of the zonal-mean zonal wind velocity ($\stackrel{\mathrm{‾}}{〈u〉}$) between 10 and 80 N at a height of 9000 m (corresponds to 300 mbar) in relation to ${w}_{{T}_{\mathit{\varphi }}}$ and wazonal and ΔTG,PD in boreal winter.
### 4.2.2 Strength of the storm track activity
The NH winter climatological (1979–2014) storm track's activity in Aeolus (Fig. 7c) is similar to ERA-Interim data (Fig. 7a).
Figure 7Eddy kinetic energy representing storm track activity in boreal winter. Panel (a) shows ERA-Interim data, and (b)(d) show data from Aeolus with different poleward temperature gradients ${w}_{{T}_{\mathit{\varphi }}}$. In (b)${w}_{{T}_{\mathit{\varphi }}}=\mathrm{0.75}$, in (c)${w}_{{T}_{\mathit{\varphi }}}=\mathrm{1.0}$ and in (d)${w}_{{T}_{\mathit{\varphi }}}=\mathrm{1.1}$. All other parameters are set to climatology. With larger gradients, the storm track activity gets stronger.
Figure 7b–d show that storm track activity increases with an increasing temperature gradient.
Figure 8Strength of the vertical integrated storm track activity in relation to ${w}_{{T}_{\mathit{\varphi }}}$ and wazonal and ΔTG,PD. The arrow points in the direction of the strongest gradient in boreal winter.
The strength of the storm track activity depends on all three components, ${w}_{{T}_{\mathit{\varphi }}}$, wazonal and ΔTG,PD (Fig. 8), in a way that the influence of ${w}_{{T}_{\mathit{\varphi }}}$ dominates the influence on storm track activity. The increased global-mean temperature leads to a general strengthening of the storm track activity (Fig. 8).
### 4.2.3 Wind velocity of the planetary waves
The wind velocity of the planetary waves is roughly as sensitive to ${w}_{{T}_{\mathit{\varphi }}}$ as to wazonal, both in terms of u* (Fig. 9a) and in terms of v* (Fig. 9b). Both meridional and zonal wind directions exhibit the same relationship, such that larger meridional and zonal temperature asymmetries lead to stronger winds. In addition, if the scaling factor ${w}_{{T}_{\mathit{\varphi }}}$ of the meridional temperature gradient is smaller than the scaling factor wazonal of the zonal temperature asymmetry, the strength of the planetary waves increases faster with higher relative changes in the meridional temperature gradient than if both have similar relative changes in magnitude. Moreover, if the relative change in the zonal temperature asymmetry is smaller than the relative changes in the meridional temperature gradient, the strength of the planetary waves increases faster with higher zonal temperature asymmetry than if both have a similar magnitude. This behavior leads to a curved structure of the azonal winds.
Figure 9Strength of planetary waves u* and v* in relation to ${w}_{{T}_{\mathit{\varphi }}}$ and wazonal and ΔTG,PD. The arrow points in the direction of the strongest gradient.
The global-mean temperature has a positive but only weak influence on the strength of planetary waves.
5 Discussion
For all investigated atmosphere variables, we observe a strengthening for higher global-mean temperature and higher absolute meridional temperature gradients and only a weak (strong) dependence on the zonal temperature asymmetry for storm tracks (planetary waves and Hadley cell width), which we discuss in comparison with results from literature in the following sections. However, most previous studies have analyzed only the combined effect of changes in several temperature components, making a direct comparison difficult.
## 5.1 Tropical circulation
### 5.1.1 Strength and width of the Hadley cell
The strength of the Hadley cell depends strongly on the meridional temperature gradient, with a stronger Hadley circulation for a larger meridional gradient (Fig. 4). Its strength is much less sensitive to global-mean temperature. A rising global-mean temperature leads to a weakening of the Hadley cell, explainable by the enhanced latent heat release under warmer conditions. The specific humidity increases faster with temperature than precipitation, therefore the strength weakens (Hill et al., 2015). Finally, it is almost insensitive to zonal temperature asymmetries.
In addition, our analysis suggests that the Hadley cell width depends nonlinearly on all three temperature components (Fig. 3). The dependence of the Hadley cell width on the meridional temperature gradient is consistent with findings from Frierson et al. (2007), using an idealized moist GCM and a full GCM.
However, our findings regarding the width of the Hadley cell are more complex than those from Frierson et al. (2007), who only observe an increase of the width with increasing global-mean temperature. Whether this is a model artifact or a true feature of tropical circulation should be assessed using high-resolution general circulation models.
In agreement to our results, Mitas and Clement (2005) detected a strengthening of the Hadley cell in their analyses using several reanalysis data sets, a rawinsonde data set and a model data set. However, they found great differences between different data sets.
Seo et al. (2014) investigated possible drivers of the Hadley cell, such as the meridional temperature gradient, gross static stability and tropopause height using CMIP5 climate models. Consistent with our results, they found a robust dependence between meridional temperature gradient and the strength of the Hadley cell in winter; a decreased meridional temperature gradient leads to a weakening of the Hadley cell.
In addition, D'Agostino et al. (2017) analyzed and compared the Hadley cell during the last glacial maximum to global warming scenarios (RCP4.5 and RCP8.5), with a focus on the dependence on subtropical stability, a near-surface meridional potential temperature gradient and the tropical tropopause level. They concluded that the meridional temperature gradient is a major driver of Hadley cell changes.
However, in both studies the atmospheric composition in terms of anthropogenic aerosols is changed, hence not only the meridional temperature gradient changes, but the global-mean temperature and the zonal temperature asymmetry also change. This makes it difficult to attribute changes in the Hadley cell to one temperature component only.
Levine and Schneider (2015) investigated the sensitivity of the Hadley cell width to Equator-to-pole temperature contrasts and global-mean temperatures using two idealized GCMs. Their results confirm our findings that an increasing Equator-to-pole temperature leads to a widening of the Hadley cell (Levine and Schneider, 2015).
## 5.2 Extratropical circulation
### 5.2.1 Strength of the jet stream
We show that the strength of the jet stream decreases with decreasing absolute meridional temperature gradient (Figs. 5 and 6).
This is in agreement with findings from Polvani and Kushner (2002) and Haigh et al. (2005). Polvani and Kushner used a simple general circulation model and showed that for sufficiently strong cooling of the polar winter stratosphere, jet streams weaken and shift poleward. Haigh et al. (2005) analyze the weakening and shift of the subtropical jet using a multiple regression analysis of the NCEP NCAR reanalysis zonal-mean zonal wind velocity. Furthermore, with a simple general circulation model, they show that the generic heating of the lower stratosphere tends to weaken the subtropical jets.
In most observational studies, a weakening of the jet is observed over the last decades, like when Archer and Caldeira (2008) use NCEP and ERA-40 reanalysis sets or when Rikus (2015) uses ERA-40 data and ERA-Interim data.
However, Pena-Ortiz et al. (2013) found that trends in both the strength and position of the jet vary strongly between different reanalysis products.
### 5.2.2 Strength of the storm track activity
In this study, we observe a strengthening of storm track activity under an increased global-mean temperature (Fig. 8).
Our results are supported by findings from McCabe et al. (2001), who observe a strengthening of the storm track activity with higher global temperatures induced by GHG forcing. This is also in agreement with Yin (2005), who investigated 15 coupled climate models and showed that storm tracks intensify under global warming. In addition, Chang et al. (2012) found that storm tracks in the upper troposphere increase in winter using 23 CMIP5 models (below 300 mbar, they found a slight decrease), and the strength of storm track activity depends strongly on the meridional temperature gradient, which is consistent with our findings.
This latter result is intuitive, as the prime role of storm tracks within the general circulation is to transport heat poleward, with a stronger temperature contrast leading to enhanced heat transport. It also directly follows from the equation of eddy kinetic energy, which depends on the meridional temperature gradient in the first place (Coumou et al., 2011).
Harvey et al. (2013) observe similar results using CMIP5 data; larger temperature differences in the Equator-to-pole temperature at upper- and lower-tropospheric levels lead to stronger storm activity.
In reanalysis data a strengthening of the storm tracks can also be observed (Schneidereit et al., 2007; Wang et al., 2006), which is supposedly because of the rising global-mean temperature. The zonal temperature asymmetry could not be responsible for a strengthening, since the zonal temperature asymmetry should be reduced in winter due to global warming. According to our results, this would lead to a weakening of the storm track activity.
O'Gorman and Schneider (2008) examined the response of storm tracks to different climate conditions by simulating an aqua-planet and by changing the longwave optical thickness in the radiation scheme of the GCM (representing variations in greenhouse gas concentrations). They found that eddy kinetic energy has a maximum for a climate with the global-mean temperature similar to that of the present-day climate. Lower or higher global-mean temperatures lead to significantly smaller values. In addition, they observed that the eddy kinetic energy increases monotonically with the meridional insolation gradient (representing changes in, for example, high-latitude surface albedo).
Similarly, Pfahl et al. (2015) investigated the behavior of extratropical cyclones under strongly varying climate conditions using idealized climate model simulations in an aqua-planet setup. They changed the meridional insolation gradient together with the longwave optical thickness, with shortwave parameters held constant. They found that the maximum of eddy kinetic energy is reached at a global-mean temperature slightly warmer than the present-day climate.
These results are different to our results, where no such peak in eddy kinetic energy can be observed. The different results may be explained by the different techniques applied to simulate higher global-mean temperature. In our study, we directly change the temperature, whereas Pfahl et al. (2015) change the longwave optical thickness with shortwave parameters held constant, which represent variations in longwave absorbers like carbon dioxide and water vapor. These changes could also change the meridional and zonal temperature asymmetry, leading to different results.
Nevertheless, we also observe a strong positive dependence between temperature gradient and eddy kinetic energy.
### 5.2.3 Wind velocity of planetary waves
In our analysis the strengthening of the planetary wave wind velocities depends on all temperature components (Fig. 9). Larger meridional and zonal temperature asymmetries as well as global-mean temperatures lead to stronger winds.
Since azonal wind components emerge due to zonal temperature asymmetries, it is expected that higher zonal temperature differences lead to stronger azonal wind components. Stronger temperature gradients cause stronger meridional wind velocities, which are deflected by the Coriolis force, therefore the zonal wind velocities are also stronger. Those wind velocities are slowed down or accelerated due to topography and the land–ocean contrast, hence the azonal component of the wind velocity will also be stronger. In addition, a higher global-mean temperature leads to more available energy in the atmosphere and therefore to a larger azonal wind velocity.
Under climate change the global-mean temperature increases, whereas the meridional temperature is expected to decrease. Our results suggest that this will have contrary effects on the strength of planetary waves.
Thus, this could explain the results which Barnes and Polvani (2013) found by analyzing the planetary waves with wave number 1–6 as well as wave numbers 1–3. She concluded that there is no significant trend in terms of the strength of the planetary waves, thus Arctic amplification does not play a dominant role in changing the undulations of the jet stream.
6 Interpretation and robustness of the model results
The large-scale dynamical atmospheric changes due to variations of the temperature components, as presented here, coincide with those expected from dynamical principles, with the possible exception of the Hadley cell width changes. This therefore first of all serves as an important validation of our SDAM atmosphere model. To our knowledge, no other SDAM model exists that captures these dynamical interactions between the large-scale circulation components of tropical circulation, jets, storm tracks and planetary waves.
The fine sampling resolution of the parameter space reveals that most variables have a linear relationship to the investigated temperature components. In retrospect, a coarser resolution sampling of the parameter space using a GCM might have sufficed for detecting the relations between temperature components and dynamical variables.
However, this linearity could only be shown through our many runs using the fast SDAM.
7 Conclusions
In this paper, we present a study on multiple fundamental components of the large-scale atmosphere dynamics to different surface temperature forcing with the statistical–dynamical atmospheric model Aeolus 1.0. Due to the statistical–dynamical approach, Aeolus 1.0 is much faster than GCMs, which allows us to do 1000s of individual simulations and thus test the sensitivity of the dynamical fields to different surface temperature changes. This way one can disentangle and separately analyze the effect of the global-mean temperature, Equator-to-pole temperature gradient and east–west temperature differences. Therefore, we are one of the first to scan the full temperature phase space. This way we can scan for nonlinearities in the system (i.e., the Hadley cell edge might be very sensitive to meridional temperature gradients only for a narrow range of temperature gradient values, and outside of that range, it is not sensitive), as done, for example, in Levine and Schneider (2015). It is important to know such nonlinearities, as it could imply more abrupt changes under global warming.
The model's climatology generally reproduces the dynamical fields of ERA Interim, especially in the Northern Hemisphere, which is the focus of our analysis. If possible, we compare our findings with results of the literature and conclude that most modeled changes are in line with theory and simulations. Exceptions are the planetary waves, which are well explained by theoretic dynamical consideration and the width of the Hadley, which could be a model artifact or a real feature. Latter should be tested with GCMs.
These results also serve as an important validation of the dynamical core of the Aeolus. We could show that Aeolus is, to our knowledge, the first model that captures the dynamical interactions expected from dynamical principles between the large-scale circulation components of tropical circulation, jets, storm tracks and planetary waves. In future work we would like to use the gained knowledge to simulate only specific temperature component configurations to further explore the dependence of the different atmospheric large-scale circulations on near-surface temperature profiles.
Code and data availability
Code and data availability.
All original data were downloaded from public archives. Code and data are stored in PIK's long-term archive and are made available to interested parties on request.
Author contributions
Author contributions.
ST, EP and DC developed the study conception. ST, SP, EP and DC developed the analysis method. DC, SP and ST developed the model code and performed the simulations. ST, JL and DC analyzed and interpreted the data. ST wrote the paper, with contributions from all co-authors.
Competing interests
Competing interests.
The authors declare that they have no conflict of interest.
Acknowledgements
Acknowledgements.
We thank ECMWF for making the ERA Interim available. The work was supported by the German Federal Ministry of Education and Research, grant no. 01LN1304A, (S.T., D.C.). The authors gratefully acknowledge the European Regional Development Fund (ERDF), the German Federal Ministry of Education and Research and the state of Brandenburg for supporting this project by providing resources for the high-performance computer system at the Potsdam Institute for Climate Impact Research.
Open Access Fund of the Leibniz Association.
Edited by: Stefano Pierini
Reviewed by: two anonymous referees
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Yin, J. H.: A consistent poleward shift of the storm tracks in simulations of 21st century climate, Geophys. Res. Lett., 32, 1–4, https://doi.org/10.1029/2005GL023684, 2005. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 41, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7938897609710693, "perplexity": 4206.246026914587}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496670156.86/warc/CC-MAIN-20191119144618-20191119172618-00479.warc.gz"} |
http://www.complex.com/music/2012/06/large-professor-tells-all-the-stories-behind-his-classic-records-part-2/large-professor-f-az-and-styles-p-the-hardest | # Large Professor f/ AZ and Styles P “The Hardest” (2008)
Album: Main Source
Label: Gold Dust
Producer: Large Professor
Large Professor: “Damn, ‘The Hardest.’ That was originally supposed to be a remix for Styles. We were working over there in Bob Perry’s studio in Williamsburg, the Chop Shop. At the time, when I did the remix for Styles, we had an ill conglomerate in there of dudes like Fame from M.O.P., AZ, Cormega, and J. Waxx Garfield. They were in there just yayin’ and nayin’ shit. And when I did that remix, everybody was raving, like, ‘That shit is crazy!’
“So Styles was in that day, and I was like, ‘Yo, you gotta put some new rhymes to this.’ And Bob Perry was like, ‘Yo, I wanna get AZ on this.’ And he gave it to A, and A is a perfectionist, so it took a minute for A to roll through. We were almost like, ‘We need to get Rakim on this,’ because A took a minute! We even did the chorus over, saying, ‘Rakim, The G-O-D.’ And right when I was doing the chorus over, A came in, and just laced it with his verse. And it was like, ‘Yes! This is what I’m talking about.’
“How that came about was nice. Late too, late in the game. That’s what surprised me. There can still be something that sounds right late in the game. I see a lot of comments like, ‘If this came out in the ’90s...’ But [we need it now]. I’m very proud of how that joint came out.” | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8177809715270996, "perplexity": 6899.186806932873}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257651820.82/warc/CC-MAIN-20180325044627-20180325064627-00339.warc.gz"} |
http://daylateanddollarshort.com/bloog/what-more-i-know-about-hyperbolic-tetrahedra/ | ## What more I know about hyperbolic tetrahedra
I have updated my note, “Hedronometric Formulas for a Hyperbolic Tetrahedron” (PDF), with a brand new formula for the volume of an arbitrary tetrahedron in terms of its face and pseudo-face areas. (See Section 8.3.)
The formula isn’t the monolithic and symmetric counterpart to Derevnin-Mednykh I’ve been seeking, but it’s a start. It’s complicated enough that I won’t attempt to render it here.
The Open Question: As one might expect, the formula involves an integral. One of the limits of integration is the subject of a Conjecture. Again, the notion is too complicated to describe here, but the gist is that I *believe* that, by appropriately assigning names to the faces (and pseudo-faces), we guarantee that the lower limit is simply one-quarter of a particular pseudo-face area. (If I’m mistaken, then that limit is a less-obvious root of a trigonometric equation.) Numerical experiments in Mathematica suggest that the conjecture is true, but I don’t have even non-constructive proof. (Nevermind that the conjecture wouldn’t really be helpful without a practical way to determine what an “appropriate assignment” of names would be.) When (if?) a properly symmetric formula is finally discovered, the order of face names won’t matter at all; but for now, it makes for an irksome little wrinkle in the formula.
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https://questioncove.com/updates/5474a52fe4b060295e932b7d | OpenStudy (geerky42):
I think Draw should have like options to begin with: blank (what we have now) as default, first quadrant graph, and graph coordinates. (graph should includes square grid) So whenever we need to display something on graph, we don't have to sketch graph every time, especially doing it perfectly. I think this should be considered, from my experience, graph-related questions are more often left unanswered probably because we usually yuck out just thinking about sketching graph to explain something visibly or something like that.
4 years ago
OpenStudy (anonymous):
Well, you can just use https://www.desmos.com/calculator and share the graph.
4 years ago
OpenStudy (geerky42):
We could just share $$\LaTeX$$ expressions using http://www.hostmath.com/ and share attactments using Dropbox, Google Drive, or Lightshot (if screenshot) And yet OpenStudy added features here, so we don't have to go through these things. I think they should just add graph coordinates for us to draw on. I don't see how hard it would be for developers to do that.
4 years ago
OpenStudy (camerondoherty):
I agree c:
4 years ago
OpenStudy (camerondoherty):
Put it into the suggestion box
4 years ago | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.31062155961990356, "perplexity": 3318.836985119259}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-51/segments/1544376826856.55/warc/CC-MAIN-20181215105142-20181215131142-00313.warc.gz"} |
https://socratic.org/questions/what-kind-of-reaction-occurs-when-potassium-is-placed-in-water | Chemistry
Topics
# What kind of reaction occurs when potassium is placed in water?
Jul 16, 2016
A zippy one with lots of spits and sparks.
#### Explanation:
$K \left(s\right) + {H}_{2} O \rightarrow K O H \left(a q\right) + \frac{1}{2} {H}_{2} \left(g\right) \uparrow$
The potassium metal reduces the water to give dihydrogen gas. Get your teacher to perform this with a small quantity of metal.
##### Impact of this question
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http://mathoverflow.net/feeds/question/23002 | Analogue of Shimura curves in the symplectic case? - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-25T07:38:27Z http://mathoverflow.net/feeds/question/23002 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/23002/analogue-of-shimura-curves-in-the-symplectic-case Analogue of Shimura curves in the symplectic case? Kevin Buzzard 2010-04-29T16:13:19Z 2010-05-20T23:07:03Z <p>My understanding is this: one can attach 2-d Galois representations to classical modular eigenforms because one can look in the etale cohomology of modular curves. For Hilbert modular forms the naive analogy breaks down, because the middle cohomology of the Hilbert modular varieties will (conjecturally at least, and possibly this is known in this case) be built up from tensor products of the 2-dimensional Galois representations attached to the automorphic representations contributing to the cohomology, and one can't unravel the prodands from the product.</p> <p>One way of resolving this problem is to instead use Shimura curves. By Jacquet-Langlands, cuspidal automorphic forms on GL_2 over a totally real field (of odd degree over Q say) biject with cuspidal automorphic forms on a quaternion algebra ramified at all but one infinite place. And we have the happy coincidence that the associated algebraic group satisfies Deligne's axioms for a Shimura variety, and we can again look in the cohomology of a curve to construct the Galois representation.</p> <p>This trick relies on two things, one local and one global: the local thing is that GL_2(R) has an inner form which is compact mod centre, and the global thing is that the quaternion algebra satisfies Deligne's axioms for a Shimura variety.</p> <p>Now let's try and generalise all of this to the symplectic case, so G=GSp_{2g} with g>1. If the base field is Q then Weissauer and others constructed the Galois representations attached to a Siegel modular form in the case g=2 by looking in the etale cohomology of a Siegel modular 3-fold. Now what about if the base is bigger? Can one pull off the same trick?</p> <p>Local question: does GSp_4(R) have an inner form which is compact mod centre?</p> <p>Global question: if so, does GSp_4(F) (F totally real) sometimes have an inner form which is compact mod centre at all but one infinite place, and for which Deligne's axioms hold? If so, might one hope to see the Galois representations attached to Hilbert-Siegel modular forms over F here?</p> <p>[Edit: the local question is solved below by Hansen. I thought that the papers he linked to would deal with the global question too, but now I suspect they don't. I've put a 150-point bounty on for the global question.]</p> <p>[Edit: because of bounty daftness I can now no longer accept any answer for this question.]</p> http://mathoverflow.net/questions/23002/analogue-of-shimura-curves-in-the-symplectic-case/23008#23008 Answer by David Hansen for Analogue of Shimura curves in the symplectic case? David Hansen 2010-04-29T16:58:38Z 2010-04-29T16:58:38Z <p>Local question: Yes, \$GU2(\mathbb{H})\$, where \$\mathbb{H}\$ is the Hamilton quaternions.</p> <p>Global question: Not an answer, but perhaps useful to you - There are two quite relevant papers of Claus Sorenson which can be found <a href="http://www.math.princeton.edu/~csorense/gal_final.pdf" rel="nofollow">here</a> and <a href="http://www.math.princeton.edu/~csorense/lower.pdf" rel="nofollow">here</a>. The first paper constructs the Galois representations attached to Hilbert-Siegel modular forms over totally real fields. The second paper concerns level-lowering for GSp4 - along the way, he proves a Jacquet-Langlands transfer to an inner form of GSp4 compact at <em>all</em> infinite places and split at all finite places (at least when F has even degree and pi satisfies the usual conditions).</p> | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.934715747833252, "perplexity": 533.9463494945994}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368705749262/warc/CC-MAIN-20130516120229-00071-ip-10-60-113-184.ec2.internal.warc.gz"} |
https://mathspace.co/textbooks/syllabuses/Syllabus-446/topics/Topic-8206/subtopics/Subtopic-107657/?activeTab=theory | # Features of linear relationships
Lesson
You will have covered the concepts here before, either in previous years or even this year. But I'll summaries the key features of linear equations below so that you have a handy reference point all in one place.
## Slope or Slope
The slope of a line (also called the slope) that passes through two known points, say $\left(x_1,y_1\right)$(x1,y1) and $\left(x_2,y_2\right)$(x2,y2) on the cartesian plane can be found easily. Slope is a measure of steepness. It is the ratio of a line's rising (or falling) to its running.
If, over a distance of $8$8 metres, a driveway rises $2$2 metres, then its slope is said to be the ratio $\frac{2}{8}=\frac{1}{4}=0.25$28=14=0.25. It is also defined as the tangent of the angle of rise as shown in this simple diagram.
Consider the following example of a line passing through two points
$\left(-3,7\right)$(3,7) and $\left(5,9\right)$(5,9) as shown here:
Looking at the two $y$y values of the two points, the rise is clearly $2$2. We could either use a formula for rise which might look like $Rise=y_2-y_1=9-7=2$Rise=y2y1=97=2 or simply notice that there is a gap of $2$2 between the two values.
Looking at the two $x$x values we could again either use the formula $Run=x_2-x_1=5-\left(-3\right)=8$Run=x2x1=5(3)=8 or simply notice that the gap between $-3$3 and $5$5 is $8$8
We also realise that the line is rising and this means that the slope is positive.
The slope, often denoted by the letter $m$m is simply the ratio given by:
$m=\frac{y_2-y_1}{x_2-x_1}=\frac{2}{8}=0.25$m=y2y1x2x1=28=0.25
From the fact that $\tan\theta=0.25$tanθ=0.25 we can use a scientific calculator to show that $\theta=\tan^{-1}\left(0.25\right)=14^\circ2'$θ=tan1(0.25)=14°2, which gives some sense to the steepness of the rise.
Note that if the line is falling, the line's slope will be negative. In such cases the acute angle the line makes with the $x$x axis will be shown on the calculator as a negative angle. Adding $180^\circ$180° to this will reveal the obtuse angle of inclination the line makes with the axis.
For example if the slope was given by $m=-0.25$m=0.25, then $\theta=180^\circ+\tan^{-1}\left(-0.25\right)$θ=180°+tan1(0.25), which simplifies to $\theta=165^\circ58'$θ=165°58
Suppose we consider the line given by $5x-2y=20$5x2y=20. By putting $x=0$x=0 we see that $y=-10$y=10 (note the negative sign here). Also, by putting $y=0$y=0, we find that $x=4$x=4. This means that the $x$x and $y$y intercepts are $4$4 and $-10$10 respectively. The situation is shown here:
Note that the rise and run can be determined from the $x$x and $y$y intercepts. The positive slope of the line shown is given as $m=\frac{10}{4}=2.5$m=104=2.5
#### Worked Examples
##### Question 1
What is the slope of the line shown in the graph given that point A(3,3) and point B(6,5) both line on the line.
##### Question 2
What is the slope of the line going through A and B?
## Finding the Equation
The line with equation $y=mx+b$y=mx+b has a slope $m$m and a y intercept $b$b . It is important to observe that this form of the line shows $y$y explicitly as a function of $x$x with $m$m and $b$b as constants, different values of $x$x will determine different values of $y$y .
For example, the line, say $L_1$L1, given by $y=3x+3$y=3x+3 has a slope of $3$3 and a $y$y intercept of $3$3. The $y$y intercept can be determined by noting that at $x=0$x=0$y=3$y=3
The line $L_2$L2 given in general form as $2x+y-8=0$2x+y8=0 can be rearranged to $y=-2x+8$y=2x+8 and the slope $-2$2 and y intercept $8$8 can be easily determined.
The line $L_3$L3 given by $5x+4y-29=0$5x+4y29=0 can be rearranged to $4y=29-5x$4y=295x and then to $y=\frac{29}{4}-\frac{5}{4}x$y=29454x with slope $m=-\frac{5}{4}$m=54 and $y$y intercept $b=7.25$b=7.25
We will now go through some of the skills in finding lines, intersections and midpoints by considering a number of questions relating to the lines $L_1,L_2$L1,L2 and $L_3$L3. As we answer the questions, check the sketch below to confirm your understanding of each answer.
##### Question 3
Is the point $A\left(1,6\right)$A(1,6) on $L_1$L1?
By substituting $\left(1,6\right)$(1,6) into $y=3x+3$y=3x+3 we see that $6=3\times1+3$6=3×1+3. This is true and so the given point is on $L_1$L1.
##### Question 4
Find $P$P, the $x$x intercept of $L_2$L2.
Since $L_2$L2 is given by $2x+y-8=0$2x+y8=0, the $x$x intercept is found by putting $y=0$y=0. Then $2x-8=0$2x8=0 and solving for $x$x, we see that $x=4$x=4. The point of intercept is thus $P\left(4,0\right)$P(4,0).
##### Question 5
Find the equation of the line $L_4$L4, which passes through $P$P and $M$M.
With $P\left(4,0\right)$P(4,0) and $M\left(5,1\right)$M(5,1), we have two methods to find $L_4$L4. Both methods require finding the slope of the line given by $m=\frac{y_2-y_1}{x_2-x_1}=\frac{1-0}{5-4}=1$m=y2y1x2x1=1054=1
Then method 1 makes use of the point slope form of the line. Specifically we know that the equation we are looking for must have the form $y=1x+b$y=1x+b. Since $M\left(5,1\right)$M(5,1) is on this line, it must satisfy it. Thus we can write $1=1\times5+b$1=1×5+b and so with a little thought, $b$b must be $-4$4. the equation of $L_4$L4 must be $y=x-4$y=x4.
The second method makes use of the point slope formula $y-y_1=m\left(x-x_1\right)$yy1=m(xx1). We know that the slope $m=1$m=1 and choosing one of the known points on the line, say $M\left(5,1\right)$M(5,1), we can determine the equation of $L_4$L4 as $y-5=1\left(x-4\right)$y5=1(x4), and this simplifies once again to $y=x-4$y=x4
##### Question 6
A line passes through the point $A\left(-2,-9\right)$A(2,9) and has a slope of $-2$2. Using the point-slope formula, express the equation of the line in slope intercept form.
##### Question 7
A line passes through the point $\left(3,-5\right)$(3,5) and $\left(-7,2\right)$(7,2)
a) Find the slope of the line
b) Find the equation of the line by substituting the slope and one point into $y-y_1=m\left(x-x_1\right)$yy1=m(xx1)
##### Question 8
a) Find the equation, in general form, of the line that passes through $A\left(-12,-2\right)$A(12,2) and $B\left(-10,-7\right)$B(10,7)
b) Find the $x$x-coordinate of the point of intersection of the line that goes through $A$A and $B$B, and the line $y=x-2$y=x2
c) Hence find the $y$y-coordinate of the point of intersection
## Intercepts of Horizontal and Vertical Lines
### Horizontal
Horizontal lines are lines that follow the horizon. They look like this...
Imagine now horizontal lines on the Cartesian plane. Horizontal lines are parallel to the $x$x axis, and as you move along a horizontal line, the $x$x value will change but the $y$y value will remain the same.
A horizontal line will:
• only have a $y$y intercept
• have an equation of the form $y=b$y=b (every point on the line has a $y$y value of $b$b)
• have a $y$y intercept = $b$b, no $x$x intercept
### Vertical
Vertical Lines are lines that go up and down (they are perpendicular to horizontal lines).
Imagine now vertical lines on the Cartesian plane. Vertical lines are parallel to the $y$y axis, and as you move along a vertical line, the $y$y value will change but the $x$x value will remain the same.
A vertical line will:
• only have an $x$x intercept
• have an equation of the form $x=b$x=b (every point on the line has an $x$x value of $b$b)
• have an $x$x intercept = $b$b, no $y$y intercept
## Parallel and perpendicular lines
### Parallel lines
These occur when we have 2 lines that NEVER cross each other and have no points in common. For this to happen the two lines need to have exactly the same slope. If they have different slopes they will cross.
Parallel lines occur often in the real world.
Consider the line $y=x$y=x, with slope=1. What would happen if we shifted every point on the line $2$2 units upwards?
We would get a new line that is parallel to $y=x$y=x, but with every point having a $y$y value that is two greater: $y=x+2$y=x+2
So parallel lines are just shifts of one another.
Parallel lines on the Cartesian Plane have the same slope (slope).
### Perpendicular Lines
The Leaning Tower of Pisa
Perpendicular is the word used to describe when one object meets another at exactly 90°. So perpendicular lines are simply lines that cross each other at exactly 90°.
To see how important the idea of perpendicular really is just think about your floor, walls and roof. If a builder does not take care to make the walls perpendicular to the floor and ceiling you'll end up with an unstable house.
The leaning tower of Pisa is a famous example of perpendicular angles gone wrong! Prior to restoration work performed between 1990 and 2001, the tower leaned at an angle of 5.5°, but the tower now leans at about 3.99°. That means the acute angle made by the tower and the ground is 86.01°.
Perpendicular lines on the Cartesian plane will have one point of intersection, and at that point of intersection the angle between them will be 90°.
## Intersections and concurrent lines
Because lines extend forever in both directions, unless they are parallel they will intersect somewhere.
Now when 3 or more lines all pass through the same point we give those lines a special name: they are called concurrent lines.
The point of intersection is called the "point of concurrency", labelled point P below.
.
### Intersections of two lines
Where two lines intersect, they share a common point. The $x$x and $y$y values of this point satisfy the equations of both lines.
#### Example
If one line has equation $y=2x+3$y=2x+3 and another has equation $y=x+6$y=x+6 then the point of intersection is where both the $y$y's are the same value. If they are the same value, then we can say that:
(at the point of intersection) $2x+3$2x+3 is equal to $x+6$x+6
$2x+3=x+6$2x+3=x+6
We can then solve for the $x$x value at the point of intersection.
$2x-x=6-3$2xx=63
$x=3$x=3
Now that we have $x$x, we can find the $y$y value at the point of intersection.
Which equation should we substitute back into? Well since the point is common to both lines, you can choose either equation.
$y=x+6$y=x+6
$y=3+6$y=3+6
$y=9$y=9
So these lines cross at the point $\left(3,9\right)$(3,9).
##### Question 9
Consider the following linear equations: $y=2x+2$y=2x+2 and $y=-2x+2$y=2x+2.
a) What are the intercepts of the line $y=2x+2$y=2x+2?
b) What are the intercepts of the line $y=-2x+2$y=2x+2?
c) Plot the lines of the two equations on the same graph.
d) State the values of $x$x and $y$y that satisfy both equations.
#### Worked Examples
##### Question 10
Examine the graph attached and assess:
1. the slope of the line.
2. the $y$y-intercept of the line.
3. the $x$x-intercept of the line
##### Question 11
Consider the graph of the linear function shown.
1. What is the slope of the line?
2. What is the $y$y-intercept?
3. What is the $x$x-intercept?
4. What is the equation of the line?
5. What is the zero of the function?
## Zeros
The zeros of a function are the values of that function that make it equal to zero.
For example for the line $y=2x+1$y=2x+1, the zero is the value of $x$x, that makes the whole function ($2x+1$2x+1) equal to zero. So we set $2x+1=0$2x+1=0 and solve for $x$x.
$2x+1=0$2x+1=0
$2x=-1$2x=1
$x=-\frac{1}{2}$x=12
Does that process look familiar? It should. It's exactly the same process we use when we are finding the $x$x intercepts. This means that the phrase zero of a function, (and also sometimes root of a function) is actually asking for the $x$x-intercepts.
### Outcomes
#### 10P.LR2.05
Graph lines by hand, using a variety of techniques | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9098852872848511, "perplexity": 761.8103618114194}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964362287.26/warc/CC-MAIN-20211202175510-20211202205510-00502.warc.gz"} |
https://www.contextgarden.net/index.php?title=Command/pagereference&curid=2996&diff=24804&oldid=24553 | # \pagereference
## Syntax (autogenerated)
\pagereference[...,...] [...,...] reference
## Syntax
\pagereference[ref] [ref]
## Example
Look in \in{chapter}[hotel] on \at{page}[hotel] for a complete
overview of accomodation in \pagereference[accomodation]Hasselt.
A chapter number and a page number will be generated when processing the input file. On another spot in the document you can refer to accomodation with;
\at{page}[accomodation]. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2936747372150421, "perplexity": 21075.821432106546}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655886516.43/warc/CC-MAIN-20200704170556-20200704200556-00065.warc.gz"} |
http://spmphysics.onlinetuition.com.my/2013/06/scalar-and-vector-quantities.html | # Scalar and Vector Quantities
### Scalar Quantity
1. Scalars are quantities which are fully described by a magnitude alone.
2. Magnitude is the numerical value of a quantity.
3. Examples of scalar quantities are distance, speed, mass, volume, temperature, density and energy.
### Vector Quantity
1. Vectors are quantities which are fully described by both a magnitude and a direction.
2. Examples of vector quantities are displacement, velocity, acceleration, force, momentum, and magnetic field.
Example:
Categorize each quantity below as being either a vector or a scalar.
Speed, velocity, acceleration, distance, displacement, energy, electrical charge, density, volume, length, momentum, time, temperature, force, mass, power, work, impulse.
Scalar Quantities:
• speed
• distance
• energy
• electrical charge
• density
• volume
• length
• time
• temperature
• mass
• power
• work
Vector Quantities
• velocity
• acceleration
• displacement
• momentum
• force
• impulse | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8314419984817505, "perplexity": 12393.949875654545}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-47/segments/1542039742793.19/warc/CC-MAIN-20181115161834-20181115183834-00072.warc.gz"} |
http://math.stackexchange.com/questions/315845/does-the-series-sum-fracxn1xn-converge-uniformly-on-x-in-0-1 | # Does the series $\sum \frac{x^n}{1+x^n}$ converge uniformly on $x\in [0,1)$?
Does the series $\sum \frac{x^n}{1+x^n}$ converge uniformly on $x\in [0,1)$?
I have no idea where to start. Could somebody give me a hint ?
Edit: Could I use something like this ?
$$\left|\frac{x^n}{1+x^n}\right|\leq x^n$$ Because $x<1$, the geometric series $\sum x^n$ converges. Therefore by the M-test we get that the series converges uniformly.
-
It does not work. In the M-test, you need to find an upper bound which does not depend on $x$. Here it only gives uniform convergence on $[0,a]$ for any $a<1$. – 1015 Feb 27 '13 at 13:33
@julien Hm... schade... Any better ideas ? ^^ – Kasper Feb 27 '13 at 13:36
@DavidMitra So your line of reasoning is: If the series was uniform convergent, it would have a continuous limit function $f$. But then it would also be continuous in a point very close to $1$, but as this is not true, we get a contradiction, right ? – Kasper Feb 27 '13 at 13:48
@Kasper You don't even need to talk about the limit $f$. Just work on the Cauchy criterion. See my edit. – 1015 Feb 27 '13 at 13:49
Better: The terms $x^n\over 1+x^n$ do not converge to the zero function uniformly on $[0,1)$. Thus the series does not converge uniformly on $[0,1)$. – David Mitra Feb 27 '13 at 13:53
The partial sums $S_N(x)=\sum_{n=0}^N \frac{x^n}{1+x^n}$ converge pointwise on $[0,1)$ to $S(x)=\sum_{n\geq 0} \frac{x^n}{1+x^n}$ by comparison with the geometric series $\sum x^n$.
Now $$S(x)-S_N(x)=\sum_{n\geq N+1} \frac{x^n}{1+x^n}\geq \frac{x^{N+1}}{1+x^{N+1}}$$ for all $x\in[0,1)$.
So, letting $x$ tend to $1$, we get $$\sup_{[0,1)}S-S_N\geq \frac{1}{2}$$ for all $N$.
Hence the convergence to $S$ is not uniform (which by definition is $\sup_{[0,1)}|S-S_N|\longrightarrow 0$ as $N\rightarrow +\infty$.)
Note: you don't even need $S$, you could simply do it with the Cauchy criterion, if you use the fact that $C([0,1),\mathbb{R})$ is complete when equipped with the uniform norm.
Then $$|S_M(x)-S_N(x)|\geq \frac{x^M}{1+x^M}$$ for all $M>N$ and all $x\in[0,1)$. Hence $$\sup_{[0,1)}|S_M-S_N|\geq \frac{1}{2}$$ and the sequence is not uniformly Cauchy.
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I don't really understand. What do you mean with $S_M$ and $S_n$ without the $(x)$ ? – Kasper Feb 27 '13 at 14:01
@Kasper $\|f\|_\infty=\sup_{[0,1)}|f|=\sup_{x\in[0,1)}|f(x)|$. – 1015 Feb 27 '13 at 14:03
aah okay. But why must $\sup_{[0,1)}|S_M-S_N|\geq \frac{1}{2}$ go to zero ? – Kasper Feb 27 '13 at 14:04
Okay, some brain malfunction, I understand it now. Thanks for your helping me out :) – Kasper Feb 27 '13 at 14:19
By the way, is the prove of @sbr, also correct ? – Kasper Feb 27 '13 at 14:19
By definition the serie $\displaystyle\sum\frac{x^n}{1+x^n}$ converges uniformly on $[0,1)$ if $$\lim_n\sup_{x\in[0,1)} \sum_{k=n+1}^{\infty}\frac{x^k}{1+x^k}=0.$$
We have $$\sum_{k=n+1}^{\infty}\frac{x^k}{1+x^k}\geq \sum_{k=n+1}^{\infty}\frac{x^k}{2}=\frac{1}{2}\frac{x^{n+1}}{1-x},$$
So it's clear that $\displaystyle\sup_{x\in[0,1)} \frac{x^{n+1}}{1-x}=+\infty,$ and hence the condition of uniform convergence is not verified.
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I don't know of the definition you gave. The cauchy criterion I know of is: The sequence of partial sums of a series $\sum g_k$ of functions is uniformly Cauchy on a set $S$ if and only if the series satisfies the Cauchy criterion: $\forall \epsilon >0 \exists N \forall x\in S:(n\geq m>N \implies |\sum_{k=m}^ng_k(x)|<\epsilon$ – Kasper Feb 27 '13 at 14:07
Oh wait this implies $|g_n(x)|<\epsilon$ for all $x\in S$, which implies $\sup\{|g_n(x)|:x\in S\}\leq \epsilon$ .... aah. right ? – Kasper Feb 27 '13 at 14:14
aaaah. things begin to make sense. So then you $\forall \epsilon >0\exists N\forall n>N :|\sup\{|g_n(x)|:x\in S\}-0|<\epsilon$ Wich proves $\limsup\{|g_n(x)|:x\in S\} = 0$ – Kasper Feb 27 '13 at 14:17
@Kasper The serie converges uniformly if the partial sum $S_n$ converge with the uniform norm to the sum $S$ i.e. $||S_n-S||_{\infty}=\sup_x|S_n(x)-S(x)|\rightarrow 0$. – Sami Ben Romdhane Feb 27 '13 at 14:56 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9733179211616516, "perplexity": 253.2993508069763}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1409535919886.18/warc/CC-MAIN-20140909043920-00116-ip-10-180-136-8.ec2.internal.warc.gz"} |
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