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strstr (a.k.a find sub string), is a useful function in string operation.
You task is to implement this function.
you should output the "first" index(from 0) of target string in source string.
If target is not exist in source, just return -1.
If source="source" and target="target", return -1.
If source="abcdabcdefg" and target="bcd", return 1.
Do I need to implement KMP Algorithm in an interview?
the interviewer just want to test your basic implementation ability.
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0.999841 |
Build me an online grocery website using angular 5 or latest.
I only need a front end using angular 5 or latest. I want a reactive single page application with the latest, smartest, and super user friendly GUI.
As a skilled front end Developer. with sufficient backend knowledge, I'll make the web site more User-friendly, Responsive and innovative for the users.
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0.999759 |
Protege User - Class "synonym"
I need to use a class "synonym" and wonder how to model it. I'm using -ontop- to acquire data from an SQL table and it works fine (great job -ontop- developers!). A given data set instance is acquired correctly in a class :Tool. Now, suppose I need to relate these data individuals wit a new class :ToolMfg as well with the least effort. In order to accomplish it, would it be to better to define :ToolMfg as a subclass of :Tool? In this case, how to search for individuals in the :ToolMfg class if the were acquired for its superclass :Tool class?
You can model it by using OWL EquivalentClassed and it works better to get the “synonym” meaning that you wanted.
but it is not always the vice-versa.
owl:equivalentClass can, of course, be a heavy cudgel as far as reasoning is concerned. If you don't want all of the entailments of one class to be replicated on the other, consider something lighter as an annotation, like skos:related, or simply using multiple labels/literals/terms (using skos:altLabel) for a single class.
James P. McCusker III, Ph.D.
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0.956294 |
Kala P Nair (Final year MPhil Scholar) presented a paper by Cunninham et al. titled "hPSC-Derived Maturing GABAergic Interneurons Ameliorate Seizures and Abnormal Behavior in Epileptic Mice", and published in the journal 'Cell Stem Cell', Volume 15, Issue 5, 6 November 2014.
Seizure disorders debilitate more than 65,000,000 people worldwide, with temporal lobe epilepsy (TLE) being the most common form. Previous studies have shown that transplantation of GABA-releasing cells results in suppression of seizures in epileptic mice. Derivation of interneurons from human pluripotent stem cells (hPSCs) has been reported, pointing to clinical translation of quality-controlled human cell sources that can enhance inhibitory drive and restore host circuitry. In this study, we demonstrate that hPSC-derived maturing GABAergic interneurons (mGINs) migrate extensively and integrate into dysfunctional circuitry of the epileptic mouse brain. Using optogenetic approaches, we find that grafted mGINs generate inhibitory postsynaptic responses in host hippocampal neurons. Importantly, even before acquiring full electrophysiological maturation, grafted neurons were capable of suppressing seizures and ameliorating behavioral abnormalities such as cognitive deficits, aggressiveness, and hyperactivity. These results provide support for the potential of hPSC-derived mGIN for restorative cell therapy for epilepsy.
The paper reports that the stem cell derived neurons homes in CA3, CA1 & DG, whereas prior work from our department reported significant localisation in the DG. Host immunity could play a role, as the latter was done on relatively immuno-competent rats.
Could developmental/maturational changes in channel rhodopsin impact the results of Optogenetic stimulation experiments reported in the paper?
Is immaturity of the stem-cell derived GABA neurons the critical factor in the success of this approach?
The immunosuppression of rats described in the study could have contributed to the success of the approach, but may add further challenges in the clinical setting as well as the pathogenesis of Epilepsy.
Sumitha Rajendra Rao (PhD Scholar) presented data from her ongoing PhD work on "Directed Differentiation of Human Embryonic Stem Cells".
Rukmani (1st year MPhil Scholar) presented the paper by Kim JY etal 2012 from World Journal of Stem Cells entitled: "Umbilical cord blood mesenchymal stem cells protect amyloid-β42 neurotoxicity via paracrine".
AIM: To understand the neuroprotective mechanism of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) against amyloid-β42 (Aβ42) exposed rat primary neurons.
METHODS: To evaluate the neuroprotective effffect of hUCB-MSCs, the cells were co-cultured with Aβ42-exposed rat primary neuronal cells in a Transwell apparatus. To assess the involvement of soluble factors released from hUCB-MSCs in neuroprotection, an antibody-based array using co-cultured media was conducted. The neuroprotective roles of the identified hUCB-MSC proteins was assessed by treating recombinant proteins or specific small interfering RNAs (siRNAs) for each candidate protein in a co-culture system.
RESULTS: The hUCB-MSCs secreted elevated levels of decorin and progranulin when co-cultured with rat primary neuronal cells exposed to Aβ42. Treatment with recombinant decorin and progranulin protected from Aβ42-neurotoxicity in vitro. In addition, siRNA-mediated knock-down of decorin and progranulin production in hUCB-MSCs reduced the anti-apoptotic effffects of hUCB-MSC in the co-culture system.
CONCLUSION: Decorin and progranulin may be involved in anti-apoptotic activity of hUCB-MSCs exposed to Aβ42.
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0.981257 |
When it comes to the question how to listen to Apple Music on Mac and PC, the most common answer must be that I'm using iTunes to play Apple Music on my computer. Although Apple Music app is available for selected mobile devices, like iPhone and iPod Touch, there is no such web application to enjoy Apple Music songs on Mac or Windows PC. Hence, you are also not able to listen to Apple Music via web browser, since there is no Apple Music web player compatible with them. It seems that iTunes is the only way to play Apple Music on computer.
Just like the quote, 'All the ways you love music. All in one place,' Apple Music as an extraordinary music streaming service is the home to 45 million songs. With the popularity of Apple Music, more and more Apple Music lovers are looking for a more suitable and convenient way to listen to Apple Music without iTunes so that subscriber can access to Apple Music tracks on other media players, like VLC, QucikTime, Windows Media Player on Mac and PC. So here, I will introduce an effective workaround to listen to Apple Music without iTunes on any device and platform.
Generally speaking, we can't access to Apple Music directly without iTunes on computer. Unlike other music services, such as Spotify, MySpace, Tidal, etc., Apple doesn’t offer an Apple Music web player for users to play Apple Music via web browser. As a result, if you would like to listen to Apple Music on a computer, iTunes is the only way. But the good news is Apple Music app is available for iPhone, iPad, iPod Touch and Android devices. You can download its official music app to get Apple Music directly. One thing you should pay attention is that Apple Music is not able to be playable on iPod Shuffle, iPod Nano and iPod Classic. In order to do it, you can refer to this source page: How to Sync Apple Music to iPod.
As a matter of fact, the main reasons why Apple Music is so attached to iTunes are that Apple Music tracks are encrypted by FairPlay DRM technology and encoded with M4P format, which leading that Apple Music members can't transfer and share Apple Music songs freely. Because of DRM M4P protection, it's impossible to play Apple Music files on non-iTunes media players and web music players. In this case, you are not able to put Apple Music to unauthorized devices and platforms.
If you have to listen to Apple Music on computer without iTunes, getting rid of DRM protection seems a perfect workaround to solve all issues. DRmare Apple Music Converter is one of the most professional Apple Music DRM removal tools, which is available for Mac and Windows operating system. It is designed to remove DRM lock from Apple Music songs and convert DRM M4P files to MP3, FLAC, M4A, M4B, WAV, and other common formats while original ID3 tags preserved. Thanks to this smart software, you can play Apple Music tracks on the computer with any media player and web player.
Note: Apart from removing DRM from Apple Music files, this smart DRM remover can work on other DRM protected audio files, like iTunes music, audiobooks and Audible audiobooks as well as convert DRM-free audio files to other target audio format according to your settings.
Now, you can download and install right version of this smart Apple Music Converter for free on your computer and use this software to remove DRM protection from Apple Music. After you test its performance and think this Apple Music DRM removal software can meet your all requirements, like output quality, conversion speed, special functions, etc. you can purchase the full version at $39.95.
Before starting this step, please make sure all Apple Music files are downloaded to your computer. In order to add downloaded Apple Music to DRmare Apple Music Converter, you can simply touch the first '+' button and choose favorite music tracks from Apple Music library. By the way, if you would like to use this tool to convert unprotected music files, you can click the second '+' button to add them.
Please click the small Format icon next to 'Convert' button, and it will pop up a new window, where you can see a list of supported output formats. Since MP3 has the highest compatibility with media players than other audio formats, we highly recommend MP3 as the output format. Besides, by touching the Edit icon at each added audio files, you are able to customize the audio codec, ID3 tags, bit rate, sample rate, etc.
Now, you can touch the Convert button to start to remove DRM protection from Apple Music and convert DRM M4P to target format, like MP3. Once the converting process finishes, you are able to freely play converted Apple Music on other media players, like Windows Media Player, VLC and QuickTime without using iTunes on your Mac and PC. It deserves to be mentioned that you are able to access to Apple Music songs even you don’t subscribe Apple Music anymore.
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0.939288 |
Gospel text (Jn 10,11-16): «I am the good shepherd. The good shepherd gives his life for the sheep. Not so the hired hand or any other person who is not the shepherd and to whom the sheep do not belong. They abandon the sheep as soon as they see the wolf coming; then the wolf snatches and scatters the sheep. This is because the hired hand works for pay and cares nothing for the sheep. I am the good shepherd. I know my own and my own know me, as the Father knows me and I know the Father. Because of this I give my life for my sheep».
Today, we value how appropriate is the image of the good Shepherd when applying it to St. Ambrose. «The good Shepherd lays down his life for his sheep», Jesus says, and this is what Ambrose actually did during his pastoral ministry in Milan. We can assert that in that local Church there was a before and an after Ambrose.
After the death of the arian Auxentius, the election of the new Bishop of Milan was becoming a very complicated issue, as partisanships and a strong division anticipated the worst; for this reason the city police led by Ambrose was summoned to guarantee order. Ambrose was getting ready to receive the baptism. At a given moment of argument and controversy, a voice was heard: "Ambrose, Bishop". The applause was unanimous, and with the crowd applauding him, he saw no other option but to accept the election. In a few days he was baptized and received the Holy orders, becoming thus the most illustrious Bishop of Milan.
His Ministry was marked by firmness, charity, prudence and his great organizational ability, all virtues that reinstated the unity of the Milanese Church: «Through justice, truth hovers over the ruins of the opinions that once ruled the world». Ambrose cultivated the study of theology, explained the Christian doctrine in gifted sermons and fostered the liturgy, thus qualifying for the title of Doctor of the Church. It was him who introduced in the Christian life and baptized Saint Augustine, whose light also shone in the history of the Church.
'I know my sheep and they know me, just as the Father knows me and I know the Father'; Thanks to this experience of prayer and knowledge of Jesus Christ, Ambrose became an excellent pastor in the image of the good Shepherd.
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0.999582 |
Why earn a Master’s degree in health information technology?
A degree within health information technology involves courses in quality improvement methods, database management and security, data analysis, clinical coding and classification systems, health data requirements and standards, and medical terminology.
As with most of the clinical industry, there is a certification process upon graduation. Many credentialing programs require consistent continuing education and recertification to sustain the credential.
Most coding credentials require a quantity of time within coding experience inside the work atmosphere.
Salaries possess a huge range within this industry, depending on where you work and the degree level obtained.
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0.999744 |
Antidepressants are the second most commonly prescribed drugs in the United States.
What causes depression? Theories include brain abnormalities and genetics as well as stress and grief.
Medications targeting brain chemicals are often used along with talk therapy to treat severe depression.
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0.979765 |
What works well for one family after divorce, may not make sense for another. Coming to an agreement with your former spouse is the best way to ensure that your child’s holiday will be as enjoyable as possible.
Ideally each of these considerations should be discussed with your former partner. It is unlikely that the children will be able to attend all of the family dinners or activities that each parent has available to them (nor is it likely that they would want to). However, open communication regarding expectations and scheduling of Holidays is often more productive if started far in advance of the actual timeframe in question. The last thing you want is to end up in family court prior to the Holidays.
Some families find that one parent having Christmas Day/Christmas Eve for parenting time and then alternating yearly works best for their family. Other families prefer to split parenting on Christmas Day into morning and evening, and then alternate that schedule yearly. However, there is no standard parenting schedule according to the law, and if these issues are brought before the Court the best interest of the children will be examined by a judge.
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0.536982 |
Keeping privacy is one of the most important aspects a homeowner seeks to find inside their house.
If you want to soundproof your house, there are different types of insulation materials readily available to bring peacefulness to the four corners of your home.
There are different types of insulation materials you can choose: the glass wool or fibreglass, mineral wool, cellulose insulation and spray foam insulation. While each material varies depending on the quality and physical properties, they all provide excellent insulation if properly installed.
Glass wool insulations, more commonly known as fibreglass insulations, are made out of glass cullet. Once processed, it resembles wool, which in turn you can install on flat surfaces like attics, basements, ceiling, and sidewalls to prevent air from coming out, thus, resulting in a low density and noise reduction.
Installing fibreglass takes a little more time and attention compared to other insulation materials. But once installed, you can visually evaluate and assess the outcome of the soundproofing.
Mineral wool, which is sometimes called rock or slag wool insulation, is from ceramics, rock and slags. Like fibreglass insulation, people use it mostly on flat surfaces, and it takes longer to install, though you can check it visually if there is any additional insulation needed.
One of the oldest forms of insulation is cellulose fibre, which is mainly processed paper, paperboard stock or wood. You can install cellulose insulation with or without binders depending on the application of soundproofing. Also, cellulose insulation has a chemical composition that allows it to resist fire.
The product of a mixture between isocyanate and polyol resin, spray foam insulation, also known as spray polyurethane foam (SPF), can expand up to 60 times from its liquid form after you spray it onto the target area.
This expansion allows the foam to seal and insulate the corners, uneven side, and hard to reach beams inside your house.
These are the three major types insulation materials. Which one is right for you?
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0.960742 |
Too Close To Call simulation What if only young people would vote?
Someone suggested an interesting scenario where young people would show up to vote way more than usual. I decided to go one step further and estimate the electoral results if only young (under 25) people voted or, the exact opposite, if only people over 65 showed up. These are extreme scenarios, but I think it's always interesting to try to see the extreme first. The reality is then a mix of these extreme cases.
Using the latest Ekos poll, I did the following manipulation: for each party, I compared the level of support among everybody to the one among young voters only. For instance, for the NDP, these numbers are respectively 24.7% and 28.8%. Therefore, young voters tend to vote more for the NDP in a proportion of 1.17, or 17% (note: to be really correct I should have compared the level of support of the over 25 to the under 25. The problem is that we only have the number of observations in each age-ranges, not the sampling weights. So I can't do the exact calculations as Ekos. In any ways, the number of under 25 isn't that big, therefore not affecting the calculations much).
Therefore, I increased the percentages for the NDP in every province by 17%. Of course, this assumes that there isn't province-young specific effect. It's an approximation, but it's the best I can given the sample size and the information provided.
For the Conservatives, the support under 25's is only 79% of the overall support. For the Liberals, the ratio is 58.7% (!). Finally, the Green enjoyed a level of support 2.46 time the national average! And for the Bloc, it's 30% higher.
You may be surprised to see the Conservatives still winning, but remember, even by being down 21%, the Conservatives would still be first in many provinces. As for the NDP, the problem for it is that the Bloc also enjoys more support among young people, thus allowing it to sweep Quebec. The party that would be really shaken is the Liberals. I didn't know their level of support was so low among the under 25. The only reason they are not even lower is because they still benefit from some huge margins during the last election. It's a simple simulation exercise, I'm well aware of the various limitations.
Same mechanic, but this time with the seniors only. This time around, the Conservatives are up 24%, the Liberals up 23%, the NDP down 25%, the Green down 62% and the Bloc down 38%.
Quite a contrast with the previous scenario. Please notice that you should compare these scenarios to my "latest projections" on the right, not the Ekos poll only. So for the CPC, they would gain 27 seats with this scenario 172 instead of 145).
Overall, what I like about this exercise is to show how different the results could be. What this means in real life is that because young people tend to vote so little (while the turnout among seniors is quite high), the overall results is closer to what older people want. So you can show this post to your friends who think that voting doesn't make any difference and try to convince them to vote. As explained also here, if young people voted more, that could potentially make a big difference.
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0.925613 |
Bioseqwestration is de capture and storage of de atmospheric greenhouse gas carbon dioxide by biowogicaw processes.
This may be by increased photosyndesis (drough practices such as reforestation / preventing deforestation and genetic engineering); by enhanced soiw carbon trapping in agricuwture; or by de use of awgaw bio seqwestration (see awgae bioreactor) to absorb de carbon dioxide emissions from coaw, petroweum (oiw) or naturaw gas-fired ewectricity generation.
Bioseqwestration as a naturaw process has occurred in de past, and was responsibwe for de formation of de extensive coaw and oiw deposits which are now being burned. It is a key powicy concept in de cwimate change mitigation debate. It does not generawwy refer to de seqwestering of carbon dioxide in oceans (see carbon seqwestration and ocean acidification) or rock formations, depweted oiw or gas reservoirs (see oiw depwetion and peak oiw), deep sawine aqwifers, or deep coaw seams (see coaw mining) (for aww see geoseqwestration) or drough de use of industriaw chemicaw carbon dioxide scrubbing.
After water vapour (concentrations of which humans have wimited capacity to infwuence) carbon dioxide is de most abundant and stabwe greenhouse gas in de atmosphere (medane rapidwy reacts to form water vapour and carbon dioxide). Atmospheric carbon dioxide has increased from about 280 ppm in 1750 to 383 ppm in 2007 and is increasing at an average rate of 2 ppm pr year. The worwd's oceans have previouswy pwayed an important rowe in seqwestering atmospheric carbon dioxide drough sowubiwity and de action of phytopwankton. This, and de wikewy adverse conseqwences for humans and de biosphere of associated gwobaw warming, increases de significance of investigating powicy mechanisms for encouraging bioseqwestration, uh-hah-hah-hah.
The Intergovernmentaw Panew on Cwimate Change (IPCC) estimates dat de cutting down of forests is now contributing cwose to 20 per cent of de overaww greenhouse gases entering de atmosphere. Candeww and Raupach argue dat dere are four primary ways in which reforestation and reducing deforestation can increase bioseqwestration, uh-hah-hah-hah. First, by increasing de vowume of existing forest. Second, by increasing de carbon density of existing forests at a stand and wandscape scawe. Third, by expanding de use of forest products dat wiww sustainabwy repwace fossiw-fuew emissions. Fourf, by reducing carbon emissions dat are caused from deforestation and degradation, uh-hah-hah-hah. Land cwearing reductions, de majority of de time, create biodiversity benefits in a vast expanse of wand regions. Concerns, however, arise when de density and area of vegetation increases de grazing pressure couwd awso increase in oder areas, causing wand degradation.
A recent report by de Austrawian CSIRO found dat forestry and forest-rewated options are de most significant and most easiwy achieved carbon sink making up 105 Mt per year CO2-e or about 75 per cent of de totaw figure attainabwe for de Austrawian state of Queenswand from 2010-2050. Among de forestry options, de CSIRO report announced, forestry wif de primary aim of carbon storage (cawwed carbon forestry) has de highest attainabwe carbon storage capacity (77 Mt CO2-e/yr) whiwe strategy bawanced wif biodiversity pwantings can return 7–12 times more native vegetation for a 10%–30% reduction of carbon storage performance. Legaw strategies to encourage dis form of bioseqwestration incwude permanent protection of forests in Nationaw Parks or on de Worwd Heritage List, properwy funded management and bans on use of rainforest timbers and inefficient uses such as woodchipping owd growf forest.
As a resuwt of wobbying by de devewoping country caucus (or Group of 77) in de United Nations (associated wif de United Nations Conference on Environment and Devewopment (UNCED) in Rio de Janeiro, de non-wegawwy binding Forest Principwes were estabwished in 1992. These winked de probwem of deforestation to dird worwd debt and inadeqwate technowogy transfer and stated dat de "agreed fuww incrementaw cost of achieving benefits associated wif forest conservation, uh-hah-hah-hah...shouwd be eqwitabwy shared by de internationaw community" (para1(b)). Subseqwentwy, de Group of 77 argued in de 1995 Intergovernmentaw Panew on Forests (IPF) and den de 2001 Intergovernmentaw Forum on Forests (IFF), for affordabwe access to environmentawwy sound technowogies widout de stringency of intewwectuaw property rights; whiwe devewoped states dere rejected demands for a forests fund. The expert group created under de United Nations Forum on Forests (UNFF) reported in 2004, but in 2007 devewoped nations again vetoed wanguage in de principwes of de finaw text which might confirm deir wegaw responsibiwity under internationaw waw to suppwy finance and environmentawwy sound technowogies to de devewoping worwd.
Settwement and deforestation surrounding de Braziwian town of Rio Branco are seen here in de striking "herring bone" deforestation patterns dat cut drough de rainforest. NASA, 2008.
In December 2007, after a two-year debate on a proposaw from Papua New Guinea and Costa Rica, state parties to de United Nations Framework Convention on Cwimate Change (FCCC) agreed to expwore ways of reducing emissions from deforestation and to enhance forest carbon stocks in devewoping nations. The underwying idea is dat devewoping nations shouwd be financiawwy compensated if dey succeed in reducing deir wevews of deforestation (drough vawuing de carbon dat is stored in forests); a concept termed 'avoided deforestation (AD) or, REDD if broadened to incwude reducing forest degradation (see Reducing emissions from deforestation and forest degradation). Under de free market modew advocated by de countries who have formed de Coawition of Rainforest Nations, devewoping nations wif rainforests wouwd seww carbon sink credits under a free market system to Kyoto Protocow Annex I states who have exceeded deir emissions awwowance. Braziw (de state wif de wargest area of tropicaw rainforest) however, opposes incwuding avoided deforestation in a carbon trading mechanism and instead favors creation of a muwtiwateraw devewopment assistance fund created from donations by devewoped states. For REDD to be successfuw science and reguwatory infrastructure rewated to forests wiww need to increase so nations may inventory aww deir forest carbon, show dat dey can controw wand use at de wocaw wevew and prove dat deir emissions are decwining.
NASA Earf Observatory, 2009. Deforestation in Mawaysian Borneo.
Subseqwent to de initiaw donor nation response, de UN estabwished REDD Pwus, or REDD+, expanding de originaw program's scope to incwude increasing forest cover drough bof reforestation and de pwanting of new forest cover, as weww as promoting sustainabwe forest resource management.
The United Nations Framework Convention on Cwimate Change (UNFCCC) Articwe 4(1)(a) reqwires aww Parties to "devewop, periodicawwy update, pubwish and make avaiwabwe to de Conference of de Parties" as weww as "nationaw inventories of andropogenic emissions by sources" "removaws by sinks of aww greenhouse gases not controwwed by de Montreaw Protocow." Under de UNFCCC reporting guidewines, human-induced greenhouse emissions must be reported in six sectors: energy (incwuding stationary energy and transport); industriaw processes; sowvent and oder product use; agricuwture; waste; and wand use, wand use change and forestry (LULUCF). The ruwes governing accounting and reporting of greenhouse gas emissions from LULUCF under de Kyoto Protocow are contained in severaw decisions of de Conference of Parties under de UNFCCC and LULUCF has been de subject of two major reports by de Intergovernmentaw Panew on Cwimate Change (IPCC). The Kyoto Protocow articwe 3.3 dus reqwires mandatory LULUCF accounting for afforestation (no forest for wast 50 years), reforestation (no forest on 31 December 1989) and deforestation, as weww as (in de first commitment period) under articwe 3.4 vowuntary accounting for cropwand management, grazing wand management, revegetation and forest management (if not awready accounted under articwe 3.3).
Continent of Austrawia from space. Austrawia is a major producer of fossiw fuews and has significant probwems wif deforestation, uh-hah-hah-hah.
Deforestation in Haiti. NASA, 2008.
As an exampwe, de Austrawian Nationaw Greenhouse Gas Inventory (NGGI) prepared in compwiance wif dese reqwirements indicates dat de energy sector accounts for 69 per cent of Austrawia’s emissions, agricuwture 16 per cent and LULUCF six per cent. Since 1990, however, emissions from de energy sector have increased 35 per cent (stationary energy up 43% and transport up 23%). By comparison, emissions from LULUCF have fawwen by 73%. However, qwestions have been raised by Andrew Macintosh about de veracity of de estimates of emissions from de LULUCF sector because of discrepancies between de Austrawian Federaw and Queenswand Governments’ wand cwearing data. Data pubwished by de Statewide Landcover and Trees Study (SLATS) in Queenswand, for exampwe, show dat de totaw amount of wand cwearing in Queenswand identified under SLATS between 1989/90 and 2000/01 is approximatewy 50 per cent higher dan de amount estimated by de Austrawian Federaw Government’s Nationaw Carbon Accounting System (NCAS) between 1990 and 2001.
Satewwite imaging has become cruciaw in obtaining data on wevews of deforestation and reforestation. Landsat satewwite data, for exampwe, has been used to map tropicaw deforestation as part of NASA’s Landsat Padfinder Humid Tropicaw Deforestation Project, a cowwaborative effort among scientists from de University of Marywand, de University of New Hampshire, and NASA’s Goddard Space Fwight Center. The project yiewded deforestation maps for de Amazon Basin, Centraw Africa, and Soudeast Asia for dree periods in de 1970s, 1980s, and 1990s.
Sprekewia formosissima in Tasmania, Austrawia.
Hakea epigwottis, Cape Raouw, Tasman Peninsuwa, Tasmania, Austrawia.
Bioseqwestration may be enhanced by improving photosyndetic efficiency by modifying RuBisCO genes in pwants to increase de catawytic and/or oxygenation activity of dat enzyme.
One such research area invowves increasing de Earf's proportion of C4 carbon fixation photosyndetic pwants. C4 pwants represent about 5% of Earf's pwant biomass and 1% of its known pwant species, but account for around 30% of terrestriaw carbon fixation, uh-hah-hah-hah. In weaves of C3 pwants, captured photons of sowar energy undergo photosyndesis which assimiwates carbon into carbohydrates (triosephosphates) in de chworopwasts of de mesophyww cewws. The primary CO2 fixation step is catawysed by ribuwose-1,5-bisphosphate carboxywase/oxygenase (Rubisco) which reacts wif O2 weading to photorespiration dat protects photosyndesis from photoinhibition but wastes 50% of potentiawwy fixed carbon, uh-hah-hah-hah. The C4 photosyndetic padway, however, concentrates CO2 at de site of de reaction of Rubisco, dereby reducing de bioseqwestration-inhibiting photorespiration, uh-hah-hah-hah. A new frontier in crop science consists of attempts to geneticawwy engineer C3 stapwe food crops (such as wheat, barwey, soybeans, potatoes and rice) wif de "turbo-charged" photosyndetic apparatus of C4 pwants.
Biochar (charcoaw created by pyrowysis of biomass) is a potent form of wongterm (dousands of years) bioseqwestration of atmosphereic CO2 derived from investigation of de extremewy fertiwe Terra preta soiws of de Amazon Basin. Pwacing biochar in soiws awso improves water qwawity, increases soiw fertiwity, raises agricuwturaw productivity and reduce pressure on owd growf forests. As a medod of generating bio-energy wif carbon storage Rob Fwanagan and de EPRIDA biochar company have devewoped wow-tech cooking stoves for devewoping nations dat can burn agricuwturaw wastes such as rice husks and produce 15% by weight of biochar; whiwe BEST Energies in NSW Austrawia have spent a decade devewoping an Agrichar technowogy dat can combust 96 tonnes of dry biomass each day, generating 30-40 tonnes of biochar. A parametric study of bioseqwestration by Mawcowm Fowwes at de Open University, indicated dat to mitigate gwobaw warming, powicies shouwd encourage dispwacement of coaw wif biomass as a power source for basewoad ewectricity generation if de watter’s conversion efficiency rose over 30%, oderwise bioseqwestering carbon from biomass as a cheaper mitigation option dan geoseqwestration by CO2 capture and storage.
Zero-tiww farming practices occur where dere is much muwching but pwoughing is not used, so dat de carbon-rich organic matter in soiw is not exposed to atmospheric oxygen, or to de weaching and erosion effects of rainfaww. Ceasing pwoughing has been awweged to encourage more ants to become predators of wood-eating (and CO2 generating) termites, awwows weeds to regenerate soiws and hewps swow water fwows over de wand.
Soiw howds more carbon dan vegetation and atmosphere combined, and in de U.S.A. most soiw wies under grazing wand. Howistic Pwanned Grazing howds tremendous potentiaw in mitigating gwobaw warming, whiwe buiwding soiw, increasing biodiversity, and reversing desertification, uh-hah-hah-hah. Devewoped by Awwan Savory, it uses fencing and/or herders, to restore grasswands by carefuwwy pwanning movements of warge herds of wivestock to mimic de vast herds found in nature where grazing animaws are kept concentrated by pack predators and forced to move on after eating, trampwing, and manuring an area, returning onwy after it has fuwwy recovered. This medod of grazing seeks to emuwate what occurred during de past 40 miwwion years as de expansion of grass-grazer ecosystems buiwt deep, rich grasswand soiws, seqwestering carbon and coowing de pwanet.
Dedicated biofuew and bioseqwestration crops, such as switchgrass (panicum virgatum), are awso being devewoped. It reqwires from 0.97 to 1.34 GJ fossiw energy to produce 1 tonne of switchgrass, compared wif 1.99 to 2.66 GJ to produce 1 tonne of corn, uh-hah-hah-hah. Given dat switchgrass contains approximatewy 18.8 GJ/ODT of biomass, de energy output-to-input ratio for de crop can be up to 20:1.
Bioseqwestration can awso be enhanced by farmers choosing crops species dat produce warge numbers of phytowids. Phytowids are microscopic sphericaw shewws of siwicon dat can store carbon for dousands of years.
Industries wif warge amounts of CO2 emissions (such as de coaw industry) are interested in bioseqwestration as a means of offsetting deir greenhouse gas production, uh-hah-hah-hah. In Austrawia, university researchers are engineering awgae to produce biofuews (hydrogen and biodiesew oiws) and investigating wheder dis process can be used to bioseqwester carbon, uh-hah-hah-hah. Awgae naturawwy capture sunwight and use its energy to spwit water into hydrogen, oxygen and oiw which can be extracted. Such cwean energy production awso can be coupwed wif desawination using sawt-towerant marine awgae to generate fresh water and ewectricity.
Many new bioenergy (biofuew) technowogies, incwuding cewwuwosic edanow biorefineries (using stems and branches of most pwants incwuding crop residues such as corn stawks, wheat straw and rice straw) are being promoted because dey have de added advantage of bioseqwestration of CO2. The Garnaut Cwimate Change Review recommends dat a carbon price in a carbon emission trading scheme couwd incwude a financiaw incentive for bioseqwestration processes. Garnaut recommends de use of awgaw bioseqwestration (see awgae bioreactor) to absorb de constant stream of carbon dioxide emissions from coaw-fired ewectricity generation and metaw smewting untiw renewabwe forms of energy, such as sowar and wind power, become more estabwished contributors to de grid. Garnaut, for exampwe, states: "Some awgaw bioseqwestration processes couwd absorb emissions from coaw-fired ewectricity generation and metaws smewting." The United Nations Cowwaborative Programme on Reducing Emissions from Deforestation and Forest Degradation in Devewoping Countries (UN-REDD Programme) is a cowwaboration between FAO, UNDP and UNEP under which a trust fund estabwished in Juwy 2008 awwows donors to poow resources to generate de reqwisite transfer fwow of resources to significantwy reduce gwobaw emissions from deforestation and forest degradation, uh-hah-hah-hah. The UK government's Stern Review on de economics of cwimate change argued dat curbing deforestation was a "highwy cost-effective way of reducing greenhouse gas emissions".
2/year in totaw BECCS capacity operating, divided between dree different faciwities.
Under a 2009 agreement, Loy Yang Power and MBD Energy Ltd wiww buiwd a piwot Fossiw fuew power pwant at de Latrobe Vawwey power station in Austrawia using bioseqwestration technowogy in de form of an awgaw syndesiser system. Captured CO2 from de waste exhaust fwue gases wiww be injected into circuwating waste water to grow oiw-rich awgae where sunwight and nutrients wiww produce heavy oiw-waden swurry dat can make high grade oiw for energy, or stock feed. Oder commerciaw demonstration projects invowving bioseqwestration of CO2 at point of emission have begun in Austrawia.
The arguments for bioseqwestration are often shaped in terms of economic deory, yet dere is a weww-recognised qwawity of wife dimension to dis debate. Bioseqwestration assists human beings to increase deir cowwective and individuaw contributions to de essentiaw resources of de biosphere. The powicy case for bioseqwestration overwaps wif principwes of ecowogy, sustainabiwity and sustainabwe devewopment, as weww as biosphere, biodiversity and ecosystem protection, environmentaw edics, cwimate edics and naturaw conservation.
Lassen Nationaw Park, Kings Creek, USA.
The Garnaut Cwimate Change Review notes many barriers to increased gwobaw bioseqwestration, uh-hah-hah-hah. "There must be changes in de accounting regimes for greenhouse gases. Investments are reqwired in research, devewopment and commerciawisation of superior approaches to bioseqwestration, uh-hah-hah-hah. Adjustments are reqwired in de reguwation of wand use. New institutions wiww need to be devewoped to coordinate de interests in utiwisation of bioseqwestration opportunities across smaww business in ruraw communities. Speciaw efforts wiww be reqwired to unwock potentiaw in ruraw communities in devewoping countries." Saddwer and King have argued dat bioseqwestration and agricuwturaw greenhouse gas emissions shouwd not be handwed widin a gwobaw emissions trading scheme because of difficuwties wif measuring such emissions, probwems in controwwing dem and de burden dat wouwd be pwaced on numerous smaww-scawe farming operations. Cowwett wikewise maintains dat REDD credits (post-facto payments to devewoping countries for reducing deir deforestation rates bewow an historicaw or projected reference rate), simpwy create a compwex market approach to dis gwobaw pubwic heawf probwem dat reduces transparency and accountabiwity when targets are not met and wiww not be as effective as devewoped nations vowuntariwy funding countries to keep deir rainforests.
The Worwd Rainforest Movement has argued dat poor devewoping countries couwd be pressured to accept reforestation projects under de Kyoto Protocow's Cwean Devewopment Mechanism in order to earn foreign exchange simpwy to pay off de interest on debt to de Worwd Bank. Tensions awso exist over forest management between de sovereignty cwaims of nations states, arguments about common heritage of mankind and de rights of indigenous peopwes and wocaw communities; de Forest Peopwes Programme (FPP) arguing de anti-deforestation programs couwd merewy awwow financiaw benefits to fwow to nationaw treasuries, priviwege wouwd-be corporate forest degraders who manipuwate de system by periodicawwy dreatening forests, rader dan wocaw communities who conserve dem. The success of such projects wiww awso depend on de accuracy of de basewine data and de number of countries invowved. Furder, it has been argued dat if bioseqwestration is to pway a significant rowe in mitigating andropogenic cwimate change den coordinated powicies shouwd set a goaw of achieving gwobaw forest cover to its extent prior to de industriaw revowution in de 1800s.
It has awso been argued dat de United Nations mechanism for Reducing Emissions from Deforestation and Forest Degradation (REDD) may increase pressure to convert or modify oder ecosystems, especiawwy savannahs and wetwands, for food or biofuew, even dough dose ecosystems awso have high carbon seqwestration potentiaw. Gwobawwy, for exampwe, peatwands cover onwy 3% of de wand surface but store twice de amount of carbon as aww de worwd's forests, whiwst mangrove forests and sawtmarshes are exampwes of rewativewy wow-biomass ecosystems wif high wevews of productivity and carbon seqwestration, uh-hah-hah-hah. Oder researchers have argued dat REDD is a criticaw component of an effective gwobaw bioseqwestration strategy dat couwd provide significant benefits, such as de conservation of biodiversity, particuwarwy if it moves away from focusing on protecting forests dat are most cost-effective for reducing carbon emissions (such as dose in Braziw where agricuwturaw opportunity costs are rewativewy wow, unwike Asia, which has sizeabwe revenues from oiw pawm, rubber, rice, and maize). They argue REDD couwd be varied to awwow funding of programs to swow peat degradation in Indonesia and target protection of biodiversity in "hot spot"—areas wif high species richness and rewativewy wittwe remaining forest. Some purchasers, dey maintain, of REDD carbon credits, such as muwtinationaw corporations or nations, might pay a premium to save imperiwed eco-systems or areas wif high-profiwe species.
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This page was wast edited on 24 February 2019, at 22:31 (UTC).
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Should I correct misspelled name on passport to get China visa?
Question: My renewed passport was returned with the first letter of my last name incorrect. I returned it, and it has been corrected on the last page of the passport. I have used this passport without issue in the UK, EU, and Caribbean.
I will be traveling to China, and thus I will need a visa. My understanding is that the visa is apt to be processed by scanning the first page (therefore the one with the incorrectly spelled last name) resulting in a visa with a misspelled last name. My concern is that immigration officials and/or airline personnel would reject my visa. What is the best solution?
Answer: I believe that the best solution is to make another request for a passport correction. To avoid repetition of the problem, you should include a signed letter explaining the error and a request that the name be corrected on the first page.
Note, there is no fee for passport corrections no matter how long it has been since your passport was issued.
Applications for corrections are given top priority and processed as expedited services (2-3 weeks).
If you need the correction more quickly, you will have to visit a regional passport agency or authorize a private expediter to submit the application for you.
Your current passport must be submitted along with Form DS-5504 however it will not be returned to you.
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0.996257 |
Humans of HR is a bi-monthly blog series in which we feature human resources thought leaders who are committed to making work more human.
Sabrina Baker spent 11 years in corporate HR environments, working for large businesses ranging in size from 5,000 to 125,000 employees. In 2010, while on maternity leave, she was laid off. She found herself sitting at home with a 3-month-old and a desire to work, so she decided to take her big-business knowledge and dial it down for startups and small businesses.
In 2011, Sabrina launched Acacia HR Solutions, an HR consultancy. She and her team help small businesses not only with day-to-day HR tasks such as legal compliance, but also coach them in HR strategy around culture and employee engagement. We spoke with Sabrina about intentional leadership, trust and autonomy, and being mindful at work.
Workhuman: What does working human mean to you?
Sabrina: Working human is about realizing that there's this whole other part to the employee you see. It’s realizing that you're dealing with a whole person and being very intentional about providing them the ability to balance what they need professionally with what they need personally. We talk a lot about how small businesses can provide more autonomy to let employees manage their lives and their schedules, which helps them be more productive.
Workhuman: Why is that autonomy so important?
Sabrina: People wear many hats. They need the ability to manage their workload as they see fit. Let's trust them to get the work done, and not necessarily on this rigid 8-5, come-into-the-office schedule. Let's trust them to open their life up and figure out how they're going to fit it all in.
Workhuman: Trust is the key there, right? If you don't trust them to get the work done, then why would you hire them in the first place?
Sabrina: Exactly. For small business owners, that's tough. I'm speaking from experience – as I start to outsource or hire employees, it's hard to for me to delegate, to let go of the things I've always done. I built this business. You have to have a process on the front end that enables you to hire people you can trust to do the job, and then you have to let go.
Workhuman: Is there anything you encourage your clients to look for in a prospective candidate that indicates they will be able to trust them?
Sabrina: I encourage them to ask questions around the amount of autonomy they've had in the past. You want people who say, ‘I love it when my boss gives me a task and then lets me go figure out how to do it. I thrive in that kind of place.’ When you're moving so fast and you're just trying to build something, you need people who you can give very quick direction to, and then they just run it.
Workhuman: In what other ways do you help your clients work more human?
Sabrina: We do a lot of leadership development training – not just how to be a good leader, but how to be intentional about leadership. Leaders need to think about how they’re treating employees – what their people have going on in their lives and how they can help them manage through that to the extent that's appropriate.
Workhuman: Are there any common areas in which leaders need development?
Sabrina: Communication is hands-down the number one request. How can leaders know what types of communication employees need? How often do they need it? How do they have difficult conversations when they have to tell an employee they're not performing or that their behavior is disruptive? I'm constantly requested to do training on communicating in a way that's very honest, especially when the feedback has to be constructive.
Workhuman: Can you tell me a story about a challenge someone you've worked with has faced and how you helped them overcome it?
Sabrina: I work with a CEO from a country where being direct is frowned upon. In his culture, it’s common to skirt around the issue. And as the CEO of a company that is growing rapidly, that is not going to work. We worked directly with him and ran scenarios: ‘When this comes up, what are you going to say? How are you going to address it?’ It took a lot of one-on-one coaching sessions, but he says he’s able to talk to people and not feel like that he's offending them, and have honest conversations that are helpful for the relationships he's building.
Workhuman: It's hard when you're afraid of offending somebody!
Sabrina: You have to step back and think, what are the right words? How can I approach this person so they hear what I have to say? It doesn't mean they're not going to get angry, but you have at least said it in a respectful way. In time, they'll digest it and realize you were doing it for their best interest.
Workhuman: What do you feel is currently the greatest need in terms of making work a better place?
Sabrina: Slowing down. Everybody is moving a million miles a minute and we're so focused on the product or the end result for the consumer. But what is the best for employees? How are they doing? Are they stressed? Overworked? Micro-managed? Being more mindful and intentional and looking at the picture internally instead of always being focused externally.
Workhuman: How do you coach businesses to do that and still meet their business needs?
Sabrina: If leaders do performance reviews or business reviews, part of it has to be from an employee standpoint. Look at employee metrics – engagement surveys, data from a rewards and recognition program, turnover rates. Metrics that tell you how you are doing internally have to be looked at as much as financials and external-facing metrics. Leaders often incorrectly assume that if they’re making money and doing what the customer wants, then everything internally must be fine.
Workhuman: Do you have any hopes or predictions for the future of HR?
Sabrina: My hope is that small business HR takes a more active role in leadership. HR has been more administrative and tactical, and there's so much value they can add around working human. They wait for permission that nobody is ever going to give them; they're just going to have to do it.
Workhuman: Do you have advice for HR leaders who want to do that but aren't sure how?
Sabrina: There are some businesses that want a transactional HR person, so first make sure you look at your environment and ask whether they would be open to having somebody who can help them focus on employee issues. And then start offering more guidance and advice when things pop up. Be vocal about how you can make sure your workforce is as healthy as your consumer brand. HR people are often waiting for somebody to see them as business partners instead of seeing themselves that way and acting accordingly.
Workhuman: What value do you get from the annual Workhuman conference?
Sabrina: I love Workhuman. This year will be my third one. It's my favorite conference of the year – the speakers, the vibe, the environment, the energy are fantastic. I tell everybody I know that they need to add it to their schedule.
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Microbial hosts offer a number of unique advantages when used as production systems for both native and heterologous small-molecules. These advantages include high selectivity and benign environmental impact; however, a principal drawback is low yield and/or productivity, which limits economic viability. Therefore a major challenge in developing a microbial production system is to maximize formation of a specific product while sustaining cell growth. Tools to rationally reconfigure microbial metabolism for these potentially conflicting objectives remain limited. Exhaustively exploring combinations of genetic modifications is both experimentally and computationally inefficient, and can become intractable when multiple gene deletions or insertions need to be considered. Alternatively, the search for desirable gene modifications may be solved heuristically as an evolutionary optimization problem. In this study, we combine a genetic algorithm and elementary mode analysis to develop an optimization framework for evolving metabolic networks with energetically favorable pathways for production of both biomass and a compound of interest.
Utilization of thermodynamically-weighted elementary modes for flux reconstruction of E. coli central metabolism revealed two clusters of EMs with respect to their ΔG p °. For proof of principle testing, the algorithm was applied to ethanol and lycopene production in E. coli. The algorithm was used to optimize product formation, biomass formation, and product and biomass formation simultaneously. Predicted knockouts often matched those that have previously been implemented experimentally for improved product formation. The performance of a multi-objective genetic algorithm showed that it is better to couple the two objectives in a single objective genetic algorithm.
A computationally tractable framework is presented for the redesign of metabolic networks for maximal product formation combining elementary mode analysis (a form of convex analysis), pathway thermodynamics, and a genetic algorithm to optimize the production of two industrially-relevant products, ethanol and lycopene, from E. coli. The designed algorithm can be applied to any small-scale model of cellular metabolism theoretically utilizing any substrate and applied towards the production of any product.
Microorganisms are increasingly utilized to synthesize a variety of products [1–3], including fuels (bio-alcohols [4–13] and biodiesels [14, 15]), specialty chemicals (amino acids [16–20]), therapeutic small-molecules [21–25] (antibacterials, anti-cancer agents, and cholesterol-lowering agents), and biopharmaceuticals (proteins, vaccines, and virus particles). A common challenge in developing high-yield cellular production systems is that organisms have evolved to optimize growth rather than the formation of a particular end-product. In principle, this challenge could be met by reprogramming the cellular objective using genetic modifications (such gene insertions, over-expressions, or deletions). In practice, the selection of appropriate gene modification targets can be a daunting task. Biomass formation as well as product synthesis requires building block precursors and cofactors provided through the concerted actions of a large number of interconnected metabolic pathways encoded by hundreds to thousands of genes. While purely empirical attempts at genetic modifications have in some cases led to impressive success , these cases have provided the exceptions rather than the rule. There is now considerable evidence that substantial improvements in productivity require manipulating the activities of multiple enzymes in different parts of cellular metabolism . In this respect, optimizing biosynthetic productivity will almost certainly benefit from computational modeling tools that systematically and efficiently explore the consequences of gene- or enzyme-level modifications across the breadth of cellular metabolism.
Currently, there exists a variety of methods for studying metabolic networks in both quantitative and qualitative manners: flux balance analysis (FBA) [29–31], 13C-labeling based metabolic flux analysis (13C-MFA) , metabolic control analysis , elementary mode analysis (EMA) , extreme pathway analysis , cybernetic modeling [36, 37], and biochemical systems theory [38–40]. Many of these methods do not necessarily identify experimentally tractable metabolic engineering targets such as gene deletions. Whereas, some algorithms based on the aforementioned methods can be used to identify such targets including minimization of metabolic adjustment (MoMA) , regulatory on/off minimization (ROOM) , OptKnock , OptStrain , OptReg , and OptGene . All six of these methods require solving an optimization problem to determine flux distributions as a means of evaluating the strain's (or mutant strain's) metabolic capabilities. Although these optimization approaches can accurately predict optimal growth and production fluxes in some cases , other experimental settings produce inaccurate predictions . In addition, situations that require the removal of numerous genes to achieve high productivity will lead to mutant strains significantly different from wild-type systems, further weakening the assumptions behind FBA. OptKnock and OptStrain utilize a bi-level optimization for determining superior mutant strains. The mixed integer linear programming (MILP) framework used in these two algorithms optimizes for one objective within another competing one (a cellular objective (biomass production) within an engineering objective (chemical production)). However, the user must provide the number of knockouts that OptKnock and OptStrain can allow. In general, exhaustively searching genomic space for knockout candidates is computationally intractable even on small-scale metabolic models (less than 100 reactions), much less on current genome-scale metabolic models (greater than 1000 reactions) due to prohibitive computation time. This situation coupled to the fact that two or three knockouts are likely not sufficient for generating a mutant capable of maximal productivity motivated the use of a genetic algorithm as demonstrated in OptGene.
Genetic algorithms (GAs) have been classically utilized as a search method for optimization of objective functions that are discontinuous, non-differentiable, stochastic, or highly non-linear. As the name implies, the underlying theory behind GAs is based on Darwinian evolution. GAs seek to evolve a population of potential solutions by crossover and mutation, and through multiple generations, the entire population will eventually "evolve" towards a global optimum (a "fitness score"). They have been used to some extent in modeling biological systems and are used as a search technique in this study. Though OptGene utilizes a GA to efficiently explore genotypic space, the framework still requires the use of a metabolic assumption required to determine metabolic fluxes (such as FBA, MoMA, or ROOM). The goal of this study was to leverage the power of a GA without the need for a metabolic assumption. As such, a primary objective of this work was to identify a genotype with a high productivity phenotype strictly from the wild-type organism's metabolic network topology, utilizing thermodynamics.
An elementary mode (EM) is a non-decomposable set of reactions (encoded by a set of genes) that leads to a functional metabolic pathway. EMA is a method of enumeration of all of the EMs of a metabolic network. As such, an EMA presents a convex analysis problem from computational geometry, in which the extreme rays of the polyhedral cone (as defined by stoichiometry and reversibility) are the EMs of the metabolic network. As a result, an EM represents a single functional pathway within overall cellular metabolism, a linear combination of a cell's EMs can be used to describe any metabolic state achievable by the cell's stoichiometry. The algorithmic complexity of this problem has not been studied in detail and has therefore been classified as at least an NP-hard (non-deterministic polynomial-time hard) problem . Empirical observations have shown that the computation time of EMA algorithms grows approximately quadratically with respect to the number of EMs, and unfortunately, the number of EMs grows exponentially with respect to network size. As a result, the computation time increases greatly with respect to network size, limiting analysis to non genome-scale metabolic networks. Nonetheless, EMA has been utilized to design strains of E. coli that are efficient at producing biomass from glucose and ethanol from five- and six-carbon sugars . In two cutting-edge applications, EMA was combined with linear programming to determine flux distributions from external measurements in lysine-producing Corynebacterium glutamicum, and to determine the metabolic fluxes of Lactobacillus rhamnosus growing on medium containing mixed substrates . EMA has also been utilized to determine flux distributions in polyhydroxybutyrate-producing E. coli, mediated by a thermodynamic analysis of the EMs .
In this study, an algorithm based on EMA, pathway thermodynamics, and a GA has been constructed with the goal of redesigning a metabolic network towards maximally producing compounds of interest while simultaneously sustaining high biomass formation. This algorithm was applied to producing ethanol and heterologous lycopene through E. coli. We addressed issues of computation speed by coupling the EMA model with a GA to efficiently explore genotypic space. This algorithm presents a combination of a variety of traits that have been explored previously by themselves: 1) it is based solely on reaction stoichiometry and network topology, independent of any experimental flux measurements (although, if flux measurements are available, they can be used to constrain the problem); 2) by the utilization of a GA, it contains an efficient search method arriving at a solution within minutes on a single-processor notebook system; 3) by the utilization of a GA, it arrives at an optimal solution in a computationally tractable amount of time; and 4) it contains the option to use a multi-objective genetic algorithm (MOGA), only utilized very recently in analysis of metabolic networks, but still within the context of FBA .
The framework is schematically shown in Figure 1. A GA is used for the optimization, by evolving a population of potential solutions (strains) towards the global optimum solution (the theoretical yield of either product or biomass on substrate). A strain is represented by a binary vector, or a chromosome, where an entry of "1" indicates a particular reaction corresponding to the position of the entry included in the strain and a "0" indicates that the reaction is not present. Each strain is then evaluated based on a fitness criterion. The strain's EMs are then enumerated and its corresponding metabolic flux vector is generated by taking a weighted linear combination of the EMs in two ways: 1) equal weighting of the EMs, or 2) weighting the EMs based on their corresponding Gibbs free energy associated with the pathway (ΔG p °). Next, the yields of biomass and product on substrate are calculated and the strain's corresponding fitness is evaluated. This fitness, a reflection of the cellular phenotype, is then used by the GA to enrich the population of potential solutions to those that have a higher fitness value. This process is repeated until one of the GA's stopping criteria is met.
Schematic overview of the framework. The following optimization objectives (fitness functions) were considered: (a) calculating metabolic fluxes through equal-weighting of the EMs, (b) calculating metabolic fluxes through weighting the EMs based on their corresponding Gibbs free energy cost, and (c) minimizing the average Gibbs free energy cost of EMs forming both product and biomass. The free energy cost of a reaction route was calculated as the stoichiometric sum of its reaction Gibbs energies. Reaction routes with net negative energy costs are considered favorable.
As test cases, two small-scale stoichiometric models were constructed of ethanol- or lycopene-producing Escherichia coli using a previously published model as a template , the details of which can be seen in Table 1. The dimensions of the ethanol and lycopene models were 47 × 60 (47 metabolites and 60 reactions) and 50 × 64 (50 metabolites and 64 reactions), respectively. The ethanol model supported 33,220 EMs: 8,389 (25.3%) of which produce ethanol, 28,336 (85.3%) of which produce biomass, and 7,156 (21.5%) of which produce both ethanol and biomass. The lycopene model supported 42,659 EMs: 9,439 (22.1%) of which produce lycopene, 32,763 (76.8%) of which produce biomass, and 4,427 (10.4%) of which produce both lycopene and biomass. A scatter plot (Figure 2) of each EM's product vs. biomass yield showed a negative correlation for both models, suggesting a pattern of trade-off between cell growth and product formation. This trade-off was most evident for EMs with either very high biomass or product yields. The theoretical yield of ethanol on glucose is 0.511 g g1 and the theoretical yield of lycopene on glucose is 0.316 g g1. There are 14 (0.04%) EMs that produce the theoretical yield of ethanol on glucose (requiring between 39 and 44 reaction removals), while there is only one EM (0.002%) that produces the theoretical yield of lycopene on glucose (requiring 36 reaction removals). EMA was conducted on a notebook equipped with an Intel® Core™ 2 Duo T9300 CPU running at 2.50 GHz, 4.0 GB memory, and a 32-bit version of Microsoft Windows Vista™ Ultimate. The computation time required to enumerate the entire set of EMs was 8.04 s ± 0.27 s (n = 10) and 12.30 s ± 0.24 s (n = 10), for the ethanol and lycopene models, respectively. More detailed information of both models can be found in Additional File1 and Additional File2.
Product vs. biomass yield for every EM in the ( a ) ethanol and ( b ) lycopene model. The number of EMs was 33,220 and 42,659 for the ethanol and lycopene models, respectively (more information on these models can be found in Table 1). Yields are expressed as fractions of the theoretical yield of product or biomass. The theoretical yields of product or biomass on substrate were determined by searching the EMs of the template-genome (the parent strain) and finding the maximal yields for product or biomass on substrate, respectively. Each point in the scatter plot corresponds to an EM (or number of EMs) with a pair of product and biomass yield values. Several EMs were associated with the same pair of product and biomass yield values, which are represented by a single point.
Information on the ethanol and lycopene models, their corresponding EMs, and their reaction and pathway change in Gibbs free energy.
Standard Gibbs energies of formation (ΔG f °) of metabolites included in the two models were calculated using group contribution theory from previously reported data . These values were used to estimate the Gibbs energy changes of reactions in the model. Technically, these estimates correspond to Gibbs energy changes defined for standard conditions (ΔG r °) (298.15 K, 1 atm, pH 7.0, all compounds at 1 M), rather than physiological conditions. Consequently, it is quite likely these estimates deviate slightly from experimentally determined values. In this study, we used these estimates as first-order approximations to derive the Gibbs energy changes across metabolic pathways (ΔG p °) as defined by the EMs. Histograms of ΔG r ° and ΔG p ° values (Figure 3) show qualitatively different distributions. The ΔG r ° histogram approximates a normal distribution about zero; whereas, the ΔG p ° histogram clearly skews in the negative direction. The mean ΔG r ° values for both models are slightly negative (Δ1.95 kcal mol1 and 1.77 kcal mol1 for the ethanol and lycopene models, respectively). Interestingly, the skewness of both distributions is different: the ethanol model has a negative skewness of 4.54 kcal mol1 while the lycopene model has a slight positive skewness of 0.42 kcal mol1. This indicates a change in distribution to slightly more energetically favorable reactions with respect to the ethanol model. The mean values for ΔG p ° are much more negative at 111.87 kcal mol1 and 88.72 kcal mol1 for the ethanol and lycopene models, respectively. Interestingly, the ethanol model contains relatively few (242, only 0.73%) thermodynamically infeasible EMs (having ΔG p ° > 0), while the lycopene model contains both a higher number of thermodynamically infeasible EMs in both number (1487) and percentage (3.49%). This exemplifies the nature of a host engineered to produce a compound it does not normally produce, showing that a variety of the pathways are not evolved.
Histogram of reaction Gibbs free energies for the ( a ) ethanol and ( b ) lycopene models. Also plotted is a histogram of the EM Gibbs free energies for the (c) ethanol and (d) lycopene models. Gibbs free energies for the EMs were computed as described in the text.
Previous analyses have shown that most metabolic reactions are near equilibrium (|ΔG r |≈ 0) ; whereas, metabolic pathways are energetically favorable (ΔG p < 0) , consistent with the trends shown in the panels of Figure 3. In this regard, the calculated ΔG p ° values should offer qualitatively correct and quantitatively reasonable estimates of the thermodynamic favorability of metabolic pathways. The change in Gibbs free energy across an entire pathway (an EM) is much more likely to be negative than the change in Gibbs free energy across individual reactions within the pathway as shown in Figure 3c and Figure 3d. Therefore, there is a strong correlation between stoichiometric feasibility and energetic favorability at the level of the pathway. Moreover, thermodynamic favorability has already been used in the past to narrow the solution space or eliminate infeasible solutions when estimating or optimizing metabolic flux distributions [57, 58]. In the algorithm, we used the ΔG p ° estimates to identify thermodynamically favorable reaction routes and enrich the mutant organism with these favored routes towards product and biomass production.
As stated previously, cellular metabolism (a flux vector) can be represented as a linear combination of the cell's EMs. It has been demonstrated previously that there exists a strong correlation between the standard change in entropy across an EM (ΔS p °) and the weighting factor of its contribution to the overall flux state in both a wild-type E. coli strain and a strain engineered for polyhydroxybutyrate production . The resulting method of determining fluxes based on weighting by ΔS p ° values was then compared to flux values reported in literature and showed a strong correlation (R2 = 0.85). In an analogous manner, we utilized Gibbs free energies for flux determination similar to previous efforts .
The flux profiles of the E. coli model (without the additional lycopene biosynthetic reactions) using both equal-weighting of the EMs and thermodynamic weighting of the EMs were compared to fluxes calculated by FBA (Figure 4). In the linear programming approach of FBA, fluxes are determined through the utilization of an objective function which maximizes the biomass equation ("growth-rate"). This is an inherently different approach in which optimization is utilized to determine the flux distribution; whereas, the approach in this algorithm only uses optimization for redesigning the cellular genotype. As such, the algorithm's flux-determination method makes no metabolic assumptions; instead, it assumes that the flux distributions are determined by well-grounded thermodynamic principles, which have been shown to be accurate in previous studies .
A bar plot of fluxes for the ethanol model calculated using ( a ) FBA linear optimization, ( b ) equally-weighted EMs, and ( c ) thermodynamically-weighted EMs.
Two case studies were performed to evaluate our algorithmic framework. In these case studies, the algorithm was tasked to identify gene knockouts that would result in the optimal product yield, biomass yield, or overall productivity (biomass yield × product yield). The two cases were: aerobic production of ethanol (a native compound) and aerobic production of lycopene (a heterologous compound), both in E. coli. The search space for the algorithm excluded reactions that computationally led to either no biomass formation or no product formation. For the ethanol case study, these reactions were BIO, FEM5, FEM6, GG1, PPP5r, TCA1, TCA2r, TCA3r, TCA4, TRA1, and TRA3 (see Additional File1 for more information). These reactions were identified by conducting a single reaction removal analysis on the wild-type model. The reactions were removed individually, the EMs were enumerated, and the EMs for each mutant were rank ordered based on their stoichiometric ethanol yield or biomass yield. If the maximal yield for either ethanol or biomass was zero, then these reactions were considered to be necessary. As a result, any strain that contained any one of these knockouts would produce either no ethanol or no biomass.
In this case study, equal weighting of the EMs and weighting the EMs based on their corresponding Gibbs free energies led to fitness values of 1.000 for ethanol production (the fitness function described in Eq. 5) requiring 13 and 11 reaction removals, respectively. This indicates that ethanol production at the theoretical yield is thermodynamically feasible. The fitness values for the coupled ethanol and biomass production fitness function were similar, though not identical: 0.266 (equal weighting) and 0.241 (thermodynamic weighting). The individual yields of ethanol and biomass were slightly different, with the ethanol fractional yield being higher in both cases. This highlights a potential advantage of utilizing a MOGA: the array of solutions will display a range of organism phenotypes that include: 1) high-producing, slow-growing, 2) low-producing, fast-growing, and 3) moderate-producing, moderate-growing. In most of the cases investigated here, a coupled fitness function (Eq. 7) leads to organisms generated by the third case. However, the potential in using a MOGA is the ability to choose what type of organism the researcher would like to construct based on ease of construction or process economics. As can be seen in Figure 5, the algorithm as formulated here is quite robust at finding the global optimum quickly, even given varying initial conditions.
A plot of average and mean fitness scores (± one standard deviation, n = 10) as a function of generation number for optimizing ethanol production using equally-weighted EMs.
Whenever ethanol was being optimized (either by itself or with biomass), reactions for either NADH dehydrogenase I/ATP synthase (OPM1) or NADH dehydrogenase II (OPM4r; also known as NADH:ubiquinone oxidoreductase II) were removed. Both NADH dehydrogenase I and II are involved in driving electron flow, while NADH dehydrogenase I is driven by oxygen. NADH dehydrogenase II uses NADH exclusively and is repressed when E. coli is grown anaerobically . The results predicted using either EM-weighting method are consistent with what is known about ethanol production through E. coli, namely, that it is mainly produced anaerobically. Also for the majority of the cases, reactions for the pyruvate oxidase (coded by poxB) and phosphate acetyltransferase (coded by pta) were identified for removal, consistent with what has been previously reported for improving ethanol production from glucose through E. coli. Depending on the weighting scheme, reactions identified for removal were fumarate reductase (coded by frdABCD), malate dehydrogenase (coded by sfcA and maeB), or lactate dehydrogenase (ldhA), all also identified by the pervious study as a near optimal producing genotype.
All of the solutions generated strains with between 16 and 24 EMs (over a three order of magnitude reduction in EMs); the different fitness functions produced mutant genomes that shared a number of similarities. Across many of the solutions, reactions in oxidative phosphorylation (as previously described) were removed. Many of the fermentative acid pathways were also removed (most notably for acetate and lactate production), which would limit the formation of undesired byproducts. Relative few reactions in glycolysis, the TCA cycle, and the PPP were removed in the different weighting schemes. It is also interesting to note that the main fermentative pathway preferred by E. coli (the acetic acid pathway) and the lactic acid pathway are chosen for removal over other secreted weak acid metabolites (formate, succinate, and pyruvate). It is therefore likely that the removal of other fermentative pathways would improve flux to the ethanologenic pathway. Taken together, the general results across many of the fitness functions suggest removal of certain fermentative and anapleurotic pathways improves cellular phenotype.
As stated, many of the knockouts identified by the algorithm presented here have been reported in E. coli. The frdA and ndh knockouts were also identified by an EMA-based algorithm and implemented in the laboratory to improve ethanol production . The nuo and atp operons were neglected in the previous model because the model was restricted to anaerobic action, therefore as stated previously, the algorithm here correctly identifies these as knockout targets (akin to operating anaerobically). However, the nuo knockout increases glucose uptake and ethanol production, while decreasing acetate, succinate, lactate, and formate formation in an anaerobic chemostat with complex medium supplemented with glucose . While the previous algorithm identified a variety of other knockouts predicted to improve production, the algorithm design was slightly different and exemplifies one of the challenges in both engineering and modeling biological systems. As has been shown here and in other places [61, 62], multiple genotypic states can lead to the same phenotypic state.
Next, the E. coli metabolic network was optimized for lycopene production. Lycopene is a C40 carotenoid natural product with antioxidant properties. Much work has been devoted to engineering lycopene biosynthesis in E. coli[63–72], due to the fact that it shares metabolic precursors (DMAPP and IPP) to other isoprenoid natural products with immense therapeutic value, such as the antimalarial sesquiterpene artemisinin and the anticancer diterpenoid paclitaxel .
Using the same approach as in the ethanol case study, the results were slightly different here. In general, the solutions generated strains with more EMs (between 18 and 174), perhaps due to the fact that the number of EMs in the parent network was nearly 30% larger for this model. First, the thermodynamically-weighted cases often converged to lower values than the equal-weighted cases when lycopene yield was included in the fitness function. Second, the fitness value for both the product yield and biomass yield optimization cases were suboptimal (less than one). While this was the case for biomass production in the ethanol model, it was not the case for product formation. This is likely due to the fact that the ethanol model had 14 EMs capable of producing the theoretical yield of product on glucose, while the lycopene model only had 1 EM that produced the theoretical yield. This genotype resulted in 36 reaction removals, which is well above the number of reaction removals found in the optimal solutions presented in Table 2 and Table 3. In both cases, the algorithms were run multiple times to confirm the result, and the same fitness values were achieved. This result may be due to the fact that the original problem was seeded with an initial population of individuals containing between two and six removals, which may bias solutions with fewer knockouts (which is certainly experimentally amenable). This could also be due to the severe drain of the cellular NADPH pool required for lycopene biosynthesis (the pathway for lycopene biosynthesis requires 16 molecules of NADPH consumed for 1 molecule of lycopene produced) .
Information on resulting strains after running the algorithm for the ethanol model.
(Information on resulting strains after running the algorithm for the lycopene model.
A pioneering study on applying computational methods (specifically, MoMA) for driving metabolic engineering studies focused on lycopene production from glucose minimal medium through E. coli. The single knockout target search identified seven knockout targets (gdhA, cyoA, gpmAB/yjtC, ppc, glyA, eno, and aceE), two of which are not included in the model used here as they pertain to amino acid metabolic pathways (gdhA and glyA). Of the other five, all were identified in some capacity by our model when optimizing for lycopene or lycopene and biomass, some of them in multiple cases. Of these computationally identified knockouts, numerous single-, double-, and triple-knockout strains were constructed in the laboratory and showed improved lycopene-producing phenotypes.
The fdhF knockout (identified here as a knockout candidate in the equal weighting cases, both with and without biomass production) improved specific lycopene production by 4%. Combining these two knockouts with a gdhA knockout (as identified by genome-scale MoMA simulations, but not considered in the model presented here) resulted in the best triple knockout strain, improving specific lycopene production by 37% . The nuo knockout improved specific lycopene production by 45% (from 1,100 ppm to 2,040 ppm) in complex medium supplemented with glucose. The other knockouts identified in this case have either not been reported with respect to improving lycopene production, or are lethal to the cell (as is the case with pgk). The aceE knockout was identified by MoMA simulations and implemented in the laboratory, improving specific lycopene production by 9% in minimal medium supplemented with glucose . The pykAF double-knockout improved specific lycopene production three-fold (from approximately 5 to 15 mg gDCW-1) in complex medium . While many of these knockouts have not been conducted in the same strain, there remain many opportunities to improve lycopene titers. Currently, lycopene production yields reported are well below the theoretical yield on glucose (316 mg/g glucose). For example, bioreactor cultivation of the over-producing ΔgdhA ΔaceE ΔfdhF triple knockout strain resulted in a lycopene yield of 2.15 mg g glucose-1, less than 1% of the theoretical yield. It is reasonable to assume that numerous additional knockouts would further aid efforts to reach this theoretical yield. Overall, the reported literature on metabolic engineering effort to improve lycopene production in E. coli strongly supports the validity of the algorithm developed here.
Given the dual objective nature of the system in question (product yield and biomass yield), it would be logical to also assess the performance of a multi-objective genetic algorithm (MOGA). MOGA maximizes/minimizes a vector of objective functions (in this case, a vector of length two) rather than a scalar objective, as was the case for the GA. As a result, there is no single, unique solution to this problem. Instead of identifying a single solution, a MOGA aims to identify a set of solutions in which an improvement in one objective requires a decrease in the other. Each solution is considered to be a non-inferior solution and the entire set of non-inferior solutions is referred to as the Pareto optima. The MOGA invoked here uses a controlled elitist genetic algorithm, a variant of the Non-dominated Sorting Genetic Algorithm-II (NSGA-II).
The multi-objective version of the algorithm was tested on the ethanol model, with both equal- and thermodynamic-weighting of the EMs. In each case, of the entire final population, only a small fraction of the individuals (<10%) had non-inferior solutions. In the case for equal-weighting of the EMs, the best individuals had fitness values of 0.3475 and 0.4375 (for Eq. 10 and Eq. 11, respectively), which has a product of 0.1520 and is much lower than the value of approximately 0.25 found in the solution of the single-objective GA with the coupled fitness function (Eq. 7). Similarly, while thermodynamically-weighting the EMs, the best individual in the Pareto optima had fitness values of 0.6885 and 0.2112 and a product of 0.1454, also much lower than the value of approximately 0.26 found in the solution of the single-objective GA with the coupled fitness function. As stated previously, an advantage of the MOGA is that it allows the user to "choose" whether to pursue constructing a strain predicted to have slightly lower growth rate but higher product yield versus a strain predicted to have a slightly higher growth rate but lower product yield (as can be seen in the scatter plots in Figure 6). However, in this study, the suboptimal values of the fitness functions and increased computational times place the MOGA approach at a disadvantage when compared to the single-objective GA.
A plot of the Pareto optima and the fitness values for the corresponding non-inferior solutions for the ethanol model using ( a ) equally-weighted EMs and ( b ) thermodynamically-weighted EMs.
Though MOGAs have not been used for optimizing the structure of metabolic networks, there has been a recently reported example of using one for optimizing an industrial bioprocess (penicillin V production from Penicillium chrysogenum) . In particular, a MOGA was used for 1) maximizing penicillin titer and maximizing penicillin yield from substrate, 2) maximizing penicillin titer and minimizing fermentation time, among other decision variables. While all of these were optimizing for two objectives, the authors invoked a tri-objective GA yield for simultaneously optimizing penicillin titer, penicillin yield, and profit.
This article presents the development and application of a computationally tractable framework which combines elementary mode analysis, pathway thermodynamics, and a genetic algorithm. The framework was then used to efficiently redesign the E. coli metabolic network for maximal production of two industrially-relevant products, ethanol and lycopene. Our results show that E. coli metabolism can be re-tailored quite efficiently for optimal or near-optimal production of a product of interest (ethanol or lycopene were examples here), biomass, or coupled product and biomass. As discussed, many of the gene knockouts identified by the algorithm to improve production formation have been tested experimentally (however, most often individually and not in combination) and have been shown to improve product formation rates.
It has been shown that the contribution of an individual EM to overall cellular metabolism can be estimated from its pathway thermodynamics . It has been proposed that this is a result of billions of years of evolution underlying the metabolic regulation and expression patterns of the genes within these pathways. As a result of this proposal, it can be assumed that a cell will attempt to reduce its overall free energy by favoring pathways (EMs) that have a more negative Gibbs free energy. Equivalently, pathways with a positive free energy are thermodynamically infeasible and are not assigned a weight in the analysis presented here (for the case of thermodynamic weighting). This allows flux determination based solely on reaction stoichiometry and thermodynamics from the EMs generated by EMA, rather than applying a metabolic assumption (maximizing growth rate) in optimization based studies (such as FBA). It is important to note that these weighting factors are not strictly predetermined but are determined within the context of the overall cellular network.
Generally speaking, equal-weighting of the EMs was shown as a proof-of-principle demonstration of the algorithm. At the same time, this was used as a reference to determine whether certain gene knockouts were predicted under both weighting schemes. Ideally, a significant fraction of the gene knockouts identified would be consistent between equal and thermodynamic weighting of the modes. As a result, the incorporation of thermodynamic calculations was an integral part of this algorithm providing for more accurate flux distributions (as compared to FBA-calculated fluxes).
The utilization of a GA to search the solution space enables the identification of an optimal genotype in a computationally tractable amount of time. The number of reaction removals required to meet these predicted optimal values are well above what is computationally feasible through exhaustive searching. For example, even ten reaction removals (the smallest number for the ethanol case study) would require evaluating 2.74 × 1017in silico organisms. With the genetic algorithm, the simulations here converged when evaluating only 2,500 in silico organisms (50 generations of 50 individuals).
Metabolic and genetic networks are highly connected with significant regulation across scales, even for microbial systems. A clear disadvantage of the model and algorithm presented, as well as most of stoichiometric modeling, is the lack of integrated regulatory information. Because these models are used to study steady-state behavior, the dynamic regulation of these systems is neglected. There have been efforts to reconstruct genome-scale transcriptional and translational (TR-TR) networks and transcriptional regulatory networks (TRNs) [74, 75]; however, the integration of these models with metabolic models has been somewhat limited [76–79]. Utilizing EMA for identifying knockout targets for improving ethanol production in E. coli allowed for simultaneous utilization of pentoses and hexoses in batch culture . This shows that a strictly stoichiometric analysis using EMA can synthetically de-regulate catabolite repression (perhaps the most well-studied means of metabolic regulation).
A potential limitation of this method is the utilization of EMA, which is computationally intensive and currently cannot be applied to genome-scale metabolic networks. As cited previously, the computation time of EMA algorithms grows approximately quadratically with respect to the number of EMs and the number of EMs grows exponentially with respect to network size. For example, an E. coli model of 110 reactions (28 of which were reversible) using any combination of glucose, succinate, glycerol, and acetate contained 507,632 EMs . However, when making many small-molecule products through E. coli, minimal medium with a single carbon-source is often used such that many of the reactions in E. coli metabolism would not acquire flux. Therefore, the engineering of high-flux pathways (glycolysis, the TCA cycle, etc.), as represented in this small-scale model, would have more impact on product formation. Very recently, the concept of elementary flux patterns was introduced, where an elementary flux pattern is defined as a set of reactions within a subsystem of a larger network that represents the basic routes of each steady-state flux of the larger network through the sub-network . They are computed using MILP and as a result, this technique can be applied to genome-scale networks, a quality mediated by the fact that computation time climbs only polynomially with respect to network size. Also very recently, an algorithm was developed to identify the K-shortest EMs within a genome-scale metabolic network utilizing integer linear programming . The algorithm here could be similarly applied to these two recently developed algorithms.
The two small-scale E. coli stoichiometric models utilized in this study were based on one previously developed . Briefly, because the previous model was developed for the utilization of multiple five- and six-carbon sugars, all of the carbon-source utilization reactions besides the glucose utilization reaction were removed; glucose was assumed to be actively uptaken by the phosphoenolpyruvate sugar transferase system. In the original model, an additional reaction was included due to a heterologous pyruvate decarboxylase from Zymomonas mobilis; this reaction is not native to E. coli and was therefore also removed.
For the lycopene case study, the ethanol model previously described served as a basis with four additional reactions added. Lycopene biosynthesis was introduced into the model and coupled to the non-mevalonate pathway (native to E. coli) previously used to support heterologous carotenoid production [83, 84]. Whenever possible, linear pathways were combined into a single reaction to reduce the size of the model. The first reaction (encoded by dxs and ispCDEFGH) held the stoichiometry: glyceraldehyde-3-phosphate + pyruvate + 2 NADPH + ATP → dimethylallyl diphosphate (DMAPP) + CO2 + 2 NADP+ + ADP. The second reaction was for the reversible isomerization of DMAPP and isopentyl diphosphate (IPP), encoded by idi. The third reaction held the stoichiometry 4 IPP → geranylgeranyl diphosphate (GGPP) and is encoded by ispA and crtE. The last reaction was for lycopene biosynthesis and held the stoichiometry 2 GGPP + 8 NADPH → lycopene + 8 NADP+, and is encoded by crtBI. To avoid the inclusion of a specific transport reaction, lycopene was not balanced in this reaction; however, it was taken into account for thermodynamic calculations. The final model included three more metabolites and four more reactions than the ethanol model.
Elementary mode analysis (EMA) was undertaken utilizing the bit pattern tree method . Developed recently, this algorithm is capable of enumerating 2,450,787 EMs over ten-times faster (on a four-thread system) than the latest release of METATOOL , and is therefore currently the fastest method for EM enumeration . The mathematical rigor associated with the bit pattern tree method and other EMA algorithms has been described previously [86–88]. The code was acquired from Professor Jörg Stelling's website http://www.csb.ethz.ch/tools/efmtool and interfaced with The MathWorks™ MATLAB software (version 7.6.0.324).
The group contribution method of Mavrovouniotis was used in this study to estimate the standard Gibbs free energy of reaction for all of the model reactions . Briefly, the group contribution method estimates the ΔG f ° of metabolites by decomposing a single molecular structure into a subset of smaller functional groups, each individually contributing to overall ΔG f ° values. The ΔG r ° is then known as a result of the known stoichiometry of the reaction in question. Although currency metabolites were not included in the stoichiometric model, they were accounted for in the Gibbs free energy calculations to ensure consistency with reported data. All of the metabolites used in the stoichiometric models utilized here had corresponding ΔG f ° values reported recently .
Chromosomal representation of the metabolic genotype for passing to the genetic algorithm is binary in nature where a "1" indicates the reaction is included in the individual and "0" indicates that the reaction is not present. For simplicity's sake, a one-to-one association between reactions in the network and genes in the GA's population was assumed. This one-to-one association decreases computation time by utilizing fewer variables for optimization. This one-to-one association does not present a significant problem experimentally, for the gene-associations with the enzymes catalyzing the reactions are well-known for E. coli due to the organism's biochemical knowledge and sequenced genome [89–91]. A binary vector of length n therefore represents a single individual in the GA population.
Initialization of a population is a critical step for determining the success of the algorithm to find the global optimum. An initial population of fifty individuals containing between two and six knockouts was seeded to the algorithm (using MATLAB's "randerr" function). This was arrived at empirically as randomly seeding individuals with approximately 50% 0's resulted in mostly non-viable strains and did not allow for the GA to reach the optimal solution. Next, each individual in the population is evaluated and given a fitness score. A previous study on using GAs to optimize genotypic space for succinate, glycerol, and vanillin production used product flux determined by optimization (FBA and MoMA) as a scoring function . As stated before, this approach relies on assumptions that may or may not be valid. Here, EMA was used as the method for scoring the individuals with fitness functions as described below.
Genetic algorithms use crossover of the chromosomes (mixing of two individuals in a population to create a new individual) and mutation (change a "0" to "1" and vice-versa with a specified frequency) to evolve the solution population. The implementation here was interfaced with The MathWorks™ MATLAB software and its Genetic Algorithm & Direct Search Toolbox. For crossover, mutation, and selection of individuals, two-point, uniform, and tournament-based methods were used, respectively. These parameters were not optimized in this study. As stated, the population size was chosen as fifty individuals, with five of the top performing individuals automatically passed to the next generation of the GA. The selection function used in the GA was either roulette- or tournament-based. The GA always terminated as a result of being below the tolerance (of the MATLAB default, 10-6) which was always between 50 and 100 generations.
As a method to reduce the computation time of the GA optimization, the GA was forced to always include (through fixed inclusion of a "1" in the individual genotype) reactions that were determined to either 1) reduce maximal product yield to zero, or 2) reduce maximal biomass yield to zero (indicating a lethal knockout). This reduced the genotypic space from 60 to 49 variables in the ethanol case study and 64 to 52 variables in the lycopene case study.
For the ethanol and lycopene case-studies, three fitness functions were examined utilizing both equal-weighting of the EMs as well as thermodynamically-weighted EMs. The flux vector can be recreated by taking the linear algebra inner-product of the EM matrix, M, with a weighting-vector, c. Here, n is the number of EMs.
Here, the T represents for temperature, which was taken to be 310.15K (37°C, the optimal temperature for E. coli growth). To satisfy the constraint that the sum of the weighting vector must be equal to unity, the weighting vector is then divided by the sum of the weighting vectors.
Three different fitness functions with different goals were examined. The fitness functions corresponding to Eq. 5, Eq. 6, and Eq. 7 are all non-dimensionalized to unity by dividing by the theoretical product of biomass yields on substrate. However, achieving the theoretical yield of both a product and biomass on a particular substrate is impossible. Equation 5 was used to optimize a network structure for yield of product, P, on a substrate, S (in this case, glucose).
The computation time for these GA simulations were between 5-20 min on a notebook equipped with an Intel® Core™ 2 Duo T9300 CPU running at 2.50 GHz, 4.0 GB memory, and a 32-bit version of Microsoft Windows Vista™ Ultimate.
Here, S is the stoichiometric matrix as described as previously and v is the flux vector.
In this optimization framework, c is a row vector containing weighting factors for individual fluxes on the objective function, z. For FBA calculations, this objective is solely the biomass reaction flux. a i and b i are the lower and upper bounds, respectively, of each flux as determined by either thermodynamics or experimental measurements.
The computation time for these MOGA simulations was much greater than the single-objective GA simulations, as expected. These simulations generally terminated after approximately 48 hours running on the same computer system described above.
BAB and BAP would like to thank the Tufts University Faculty Research Awards Committee for support. BAB would also like to thank Ryan Nolan and Mark Walker for their helpful discussions.
BAB conceived of the study, participated in its design, performed simulations, and helped draft the manuscript. HS calculated thermodynamic values. KL conceived of the study, participated in its design, and helped draft the manuscript. BAP participated in the study's design and helped draft the manuscript. All authors read and approved the final manuscript.
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0.873308 |
Internet service provider iiNet, the Internet Society of Australia (ISOC-AU), and industry bodies the Australian Mobile Telecommunications Association (AMTA) and the Communications Alliance have all called for restrictions on the government agencies that can issue requests under the Telecommunications Act 1997 for ISPs to block websites.
Under Section 313(3) of the act a carriage service provider must "give officers and authorities of the Commonwealth and of the States and Territories such help as is reasonably necessary" for "enforcing the criminal law and laws imposing pecuniary penalties", "assisting the enforcement of the criminal laws in force in a foreign country", "protecting the public revenue", and "safeguarding national security".
The use by government agencies of Section 313 of the act to request that ISPs block subscriber access to websites is currently the subject of a parliamentary inquiry by the Standing Committee on Infrastructure and Communications.
The legislation has been used to order ISPs to block their customers from accessing websites hosting illegal material; for example, the Australian Federal Police has ordered the blocking of websites that host child abuse images.
The use of the act to block websites became a subject of debate in 2013 after the Australian Securities and Investment Commission ordered a number of ISPs to block access to websites being employed for investment fraud.
ASIC ordered ISPs to block IP addresses linked to a number of the websites, in the process blocking access to unrelated websites.
In its own submission to the inquiry, the watchdog organisation revealed that people issuing the Section 313 notices "were not aware that a single IP address can host multiple websites".
An internal review triggered by the incident found that the organisation's Section 313 notices had erroneously led to the blocking of more than 250,000 websites that hosted "no substantive content" related to ASIC investigations.
Part of the problem with the legislation as it currently stands is that it's too broad with respect to the organisations that can employ Section 313, according to iiNet's submission to the inquiry.
Section 313 as stands mean there is an "almost unlimited range of government and law enforcement agencies that can rely on the powers set out in section 313," the submission states.
"The use of section 313 should be restricted to a far narrower range of the critical law enforcement, anticorruption and national security agencies that have a demonstrated need for such a power to block online services. It would not be necessary or proportional, for example, for local councils to be able to rely on section 313(1) or (3) to request an ISP to block a site."
A joint submission by the Australian Mobile Telecommunications Association and the Communications Alliance argued that only "organisations dealing with law enforcement at major crime level, national security, and revenue matters of major significance" and national security agencies should be able to use Section 313(3).
"The Associations note that some service providers have received s.313(3) requests in the past from organisations such as the RSPCA and ASIC, and indeed even from non-Government entities such as legal assistance organisations."
Similarly, ISOC-AU argued that "the list of agencies permitted to make such requests should be kept as small as possible".
"This list should be no larger than those agencies that are currently able to request surveillance warrants, and such requests should be centrally managed through a single agency, such as the [Australian Communications and Media Authority or] the Attorney-General’s Department," the organisation's submission states.
iiNet said that a court order to block websites should be required, and that such an order should be sent to all ISPs.
"Requiring only a small section of the industry to block sites will be ineffective and therefore, creates unnecessary costs for those required to implement blocks," the organisation argued.
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0.983144 |
In order to meet the requirement of large scale real-time near-duplicate video detection, this paper has achieved two goals. First, this paper proposes a more compact local image descriptor which is termed as gradient ordinal signature (GOS). GOS not only has the advantages of low dimension, simplicity in computation, and high discrimination but also is invariant to mirror reflection, rotation, and scale changes. Second, applying the characteristics of the proposed GOS and combining with the embedding theory of metric spaces, this paper proposes an efficient similarity search method based on the fixed-point embedding (FE). A main advantage of FE is that its parameters have good controllability, and its performance is stable and not sensitive to dataset changes. On the whole, the goal of our approach focuses on the speed rather than the accuracy of near-duplicate video detection. We have evaluated our method on four different settings to verify the two goals. Specifically, the tests include image and video datasets, respectively, to evaluate the performance of GOS. Experimental results demonstrate the effectiveness, efficiency, and lower memory usage of GOS. Furthermore, the third test compares FE with locality sensitivity hashing. FE also shows a speed improvement of about ten times and saves more than 60% in memory usage. The fourth test demonstrates that the combination of GOS and FE for near-duplicate video detection can achieve better overall efficiency than the state-of-the-art methods.
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0.9487 |
Skeeal contoyrtyssyn steampunkagh taitnyssagh dy liooar. Va'n prose beggan garroo nish as reesht, as er lhiam dy verragh aavaght elley blass noa er myr skeeal "taitnyssagh as so-lhaih". She ym-lioar nane t'ayn, agh nagh vel ad loayrt er ny traghyn t'er ngoll shaghey! Ny keayrtyn er lhiam dy row mee er goayl skeeal-roish ennagh. Ta Green soilshaghey dy jeean dy nee seihll groamagh t'ayn, as ta shen cur blass elley er yn ard-charracteyr. Cha nod fer berçhagh ooasle ve ny 'eniagh glen as eshyn goaill ayrn 'sy chorys heshoil t'ayn, agh t'eh jannoo reddyn feeu ny yei shen. Red elley, cha nel eh jiooldey insh dooin ny ta goll er, as folliaghey eh derrey jerrey'n skeeal; ta fys mie ain dy leah, as she cummey as jerrey y feaysley ta bun as bree y skeeal. Ghow mee soylley jeh'n skeeal trooid as trooid, as she seihll steampunkagh mie t'ayn. Ta blass garroo er y phrose, agh s'baghtal dy nee aght as daltyn ta cummal seose y lioar, as ta Green screeu adsyn mie dy liooar. Kionneeym y nah lioar, foddee, as yeearree dy bee ny karracteyryn ny smoo, wahll, nyn garracteyryn, rish sheeyney y skeeal.
Bea-skeeal caslyssagh mie er bashtal mychione aase 'syn Chorea. Ta caillin feaysley magh beggan er veggan bun as keeayllyn caillinys as bwoirrinys, 'sy chorp as 'sy chultoor mygeayrt eck. Ga dy vel blass bardaght lajer ayns ny coloayrtyssyn dy mennick, ta smooinaghtyn as ennaghtyn aeglee ainjyssagh ry-akin (as ry-chooinaghtyn!) ayns shoh.
Lhaih mee 2 lioar, va 80 aym yn çhiaghtin shoh chaie, myr shen ta 78 faagit dou nish. Shegin dou lhaih 28 lioaryn ayns 20 shiaghteeyn.
An enjoyable, action-packed steampunk adventure story. The prose was somewht clunky, and another editing pass could have boosted this into "action-packed and well-written". This is volume one of the series, but at times the references to past events made it feel like volume two, as though I was missing something. Green is cheerfully frank about how grim the setting is for all but the upper classes, and this paints the protagonist as something less than a real hero. You can't be likeable when you're knowingly part of that system, but his exploits are still unselfish. I also appreciated Green letting the reader know what's going on, rather than trying to hide it all. Overall I enjoyed the story, and I thought the world was a satisfying take on the steampunk theme. The prose is a little rough around the edges, but action and style are clearly the focus here, and Green delivers that well enough. I'll consider getting the next book, and hope that we might see some more depth to the characters as the story continues.
An excellent graphical memoir of growing up in Korea, and a young girl's slow unfolding discovery of what it means to be a girl, both biologically and culturally. A lot of familiar, believable childhood emotions and thoughts come across here, despite the rather poetic flavour many of the conversations have.
I read 2 books this week, I had 80 last week, so 78 are left over. I 78 books to read in 20 weeks.
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0.985506 |
Carl Maria Friedrich Ernst von Weber (18 or 19 November 1786 – 5 June 1826) was a German composer, conductor, pianist, guitarist and critic, one of the first significant composers of the Romantic school. Weber's operas Der Freischütz, Euryanthe and Oberon greatly influenced the development of the Romantische Oper (Romantic opera) in Germany. Der Freischütz came to be regarded as the first German "nationalist" opera, Euryanthe developed the Leitmotif technique to an unprecedented degree, while Oberon may have influenced Mendelssohn's music for A Midsummer Night's Dream and, at the same time, revealed Weber's lifelong interest in the music of non-Western cultures. This interest was first manifested in Weber's incidental music for Schiller's translation of Gozzi's Turandot, for which he used a Chinese melody, making him the first Western composer to use an Asian tune that was not of the pseudo-Turkish kind popularized by Mozart and others. A brilliant pianist himself, Weber composed four sonatas, two concertos and the Konzertstück in F minor (concert piece), which influenced composers such as Chopin, Liszt and Mendelssohn. The Konzertstück provided a new model for the one-movement concerto in several contrasting sections (such as Liszt's, who often played the work), and was acknowledged by Stravinsky as the model for his Capriccio for Piano and Orchestra. Weber's shorter piano pieces, such as the Invitation to the Dance, were later orchestrated by Berlioz, while his Polacca Brillante was later set for piano and orchestra by Liszt. Weber's compositions for woodwind instruments occupy an important place in the musical repertoire. His compositions for the clarinet, which include two concertos, a concertino, a quintet, a duo concertante, and variations on a theme (posthumously), are regularly performed today. His Concertino for Horn and Orchestra requires the performer to simultaneously produce two notes by humming while playing—a technique known as "multiphonics". His bassoon concerto and the Andante e Rondo ungarese (a reworking of a piece originally for viola and orchestra) are also popular with bassoonists. Weber's contribution to vocal and choral music is also significant. His body of Catholic religious music was highly popular in 19th-century Germany, and he composed one of the earliest song cycles, Die Temperamente beim Verluste der Geliebten ([Four] Temperaments on the Loss of a Lover). Weber was also notable as one of the first conductors to conduct without a piano or violin. Weber's orchestration has also been highly praised and emulated by later generations of composers – Berlioz referred to him several times in his Treatise on Instrumentation while Debussy remarked that the sound of the Weber orchestra was obtained through the scrutiny of the soul of each instrument. His operas influenced the work of later opera composers, especially in Germany, such as Marschner, Meyerbeer and Wagner, as well as several nationalist 19th-century composers such as Glinka. Homage has been paid to Weber by 20th-century composers such as Debussy, Stravinsky, Mahler (who completed Weber's unfinished comic opera Die drei Pintos and made revisions of Euryanthe and Oberon) and Hindemith (composer of the popular Symphonic Metamorphosis of Themes by Carl Maria von Weber). Weber also wrote music journalism and was interested in folksong, and learned lithography to engrave his own works.
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0.996703 |
If I sign up for a credit card that has a sign-up bonus (i.e., spend $500 in 3 months and get $100 cash; spend $1000 in 3 months and get 30,000 miles), pay the specified amount and earn the reward, and close the account, how long would I typically have to wait to perform the same maneuver again, on the same card? Is this even possible?
Assuming the credit card companies allow a customer to sign up again every 12 months, let's say I sign up for a card, get the bonus, and close the account. If I apply again the following month, will the credit card issuer A) deny me outright with no hard inquiry into my credit; B) deny me with a hard inquiry into my credit; or C) approve me but not grant the sign-up bonus, perhaps because there is a line in the contract which states this will happen?
Once I get the sign-up bonus for a given credit card, will that sign-up bonus forever be gone on that particular card? Must I wait for the issuer to issue a new card with a different sign-up bonus offer?
Each company will have rules regarding their new account program.
The goal is to bring in new customers. Their data shows that if they can capture a new customer with the proper age, income, and credit score; in one year they will generate X in fees, and interest. They also know that a certain percentage will just meet the minimum usage, and then bail. Others will stay a year then quit. Others will stay for decades.
They will put in place time limits, where if you want to get another new customer bonus you will have to wait. They will happily give you a new card before the lock-out-period ends, but it won't get the new customer bonus.
Yes it is possible to game the system to maximize the new card bonuses. But that takes time, it generates hard inquiries every year. It means that the card shouldn't be used to recurring transactions, or those will need to be changed every year. Your credit score will take a hit because you will always have new credit.
Remember to cancel the card or the clock doesn't reset. Also expect that the canceled card will contact to try to bring you back. They may offer a new deal, but they will call you, email you and send you offers in the mail. Also if you don't cancel the card the amount of credit you have available could eventually hinder your ability to get credit.
Decades ago a family friend did this with bank accounts. They did the minimum deposit to get the toaster, set of drinking glasses or $10. Not many do this, become a serial new customer, but there is nothing to forbid this.
How is Average Length of Credit determined by the Credit Agencies?
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0.999923 |
Psychology has measures to mitigate issues of police overreaction ["SC man killed by cop mourned," News, April 12]. Terms like desensitization and stress inoculation come to mind. The idea is to incorporate into training, and continuing education, situations in which suspects behave uncooperatively or abusively.
Simple verbal reviews would be inadequate. A well-designed program would make such situations as "real" as possible and include methods like role-playing and virtual reality.
Depending on the budget, you could have some officers play the suspect and act belligerently or try to escape, and have an officer being trained respond. There would have to be an education component: breathing controls, muscle relaxation and self-talk that would dampen the arousal of the situation.
Experts could work out scripts before training that would allow certain phrases to compete with the kind of self-talk that someone would naturally experience in a dangerous situation -- such as, "This guy's a criminal." Replace it with, "Let me stay in control of the situation. I need to rely on my breathing techniques, relax my muscles and be sure I don't overreact here."
This should be an important component of police training. Police departments spend hours training officers how to use a Taser. Equal time should be dedicated to stress inoculation.
Editor's note: The writer is a retired clinical psychologist, who has a doctorate in his field.
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0.999896 |
Which is the world's highest, driest, coldest and windiest continent? Which is the only place on earth not yet ruined, still untouched by the destructive hand of man? Australasia? Or "the ice", as Antarctica is referred to by its old friends? Of course, the former still has 5 large areas as yet untouched, but nothing like the huge virgin expanses of "the ice".
Now, the virgin continent has become the source of yet another conflict between scientists and environmentalists. The latter believe that 10 Antarctica must be maintained as such and that scientists should be careful not to leave behind anything that might damage the environment. Scientists say that limited local environmental impact has to be expected and accepted, because the continent is an important natural laboratory for estimating the effects humans have on the globe, even 15 functioning as a kind of early-warning system for the whole planet.
There is a treaty designed to protect this continent which has only 8,000 inhabitants and most of them not permanent , but contains 70% of the world's fresh water. Oil and minerals cannot be exploited, 20 but what controls are there on the growing number of scientists, explorers and even tourists?
2. According to the passage what is the main reason for the conflict between the scientists and the environmentalists?
(A) The possible environmental damage.
(B) The use of Antarctica as a laboratory.
(C) Antarctica is becoming a tourist spot.
(D) Antarctica is being used as an early-warning system.
3. What cannot be said about Antarctica?
(A) It's the only place on earth still not ruined.
(B) It's the coldest continent.
(C) It is still untouched.
(D) It is the continent with the least fresh water.
4. Which of the following can people still do in Antarctica?
(C) Dig for prescious stones.
5. What can be inferred from the passage?
(A) Antarctica cannot be saved.
(B) Antarctica has too few inhabitants to worry about.
(C) Antarctica is worth saving.
(D) There is a treaty about Antarctica, so there is nothing to worry about.
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0.96563 |
Police officers on Saturday stand at the entrance to a hiking trail where two French tourists were killed in Salta, Argentina.
(CNN) -- Authorities in Argentina have arrested a second suspect in the case of two French tourists found dead near a hiking trail last week, police said on Tuesday.
They did not name the suspect in a short statement, which made no mention of a possible motive in the murders.
The state-run Telam news agency reported that the suspect is accused of having something to do with the weapon used to kill the two tourists.
Authorities arrested a first suspect in the case on Monday. He was subsequently released because of a lack of evidence, the agency said.
Other tourists found the bodies of the two female victims, who were 23 and 29 years old, Telam reported. They were last seen in the hostel where they were staying on July 16.
The women were "viciously" killed, one shot in the head and the other in the back, the agency said, citing Marcelo Baez, a spokesman for the judicial authority in Salta province.
Baez said authorities suspect they could have been held for several days before being killed. Their bodies were found Friday, the Salta government said in a statement.
Evidence indicates one of the victims was sexually assaulted, Telam said, citing police sources.
Their bodies were found in the area of the San Lorenzo ravine in northern Argentina.
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0.999587 |
You are Henry the son of a blacksmith. Once in the whirlpool of the events of the Civil War, you helplessly watch the invaders storm your village and carve your friends and family. By miraculously avoiding a cruel fate, you will raise your sword for retribution. Take revenge for the death of your parents and help drive away the invaders! Bohemia, located in the heart of Europe, is famous for its cultural traditions, silver reserves and many castles.
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0.999912 |
I read a lot of news and like to share a lot of it with friends, family, and professional networks using various services on the web. The easiest way for me to collect, consume, and distribute this content is through social media services such as Google Reader, Twitter, Facebook, and Email.
I'm also always on the go, and it's increasingly rare that I can devote enough time during the week in front of a traditional computer or laptop to read all the news, information, and stay up to date as much as I want to. Therefore, it's an easy investment for me to own a smartphone to consume content whenever I have a minute or two of downtime. This makes information consumption much easier and fits better into my schedule. I also recently purchased a tablet to fill the intermediate gap when the screen size of a smartphone just isn't suitable for some content, but a tablet is still portable enough to carry with me most of the time.
Now, when you're browsing any content that you want to share, click the appropriate bookmarklet from the bookmark menu and the service will prompt you to edit/send the item.
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0.984054 |
Did your dog just pick up this nasty habit of eating poop?
Is he sick and how to stop him from eating his own feces?
I understand your concern and knee-jerk reaction to this gross habit. You may probably be thinking why on earth does your dog want to consume his own stool when there are so much delicious things to eat.
Although you may find this habit utterly gross but there is nothing to be immediately alarmed as this is a quite normal behavior in puppies and dogs.
In fact stool-eating, technically known as Coprophagia, is common in many animals and there are a variety of reasons for this behavior.
For example, rabbits and hamsters are commonly known to eat their own feces in order to extract more nutrients from their food.
So here are some of the top reasons why your dog eats his own poop.
Once you have accepted that it is a normal and natural behavior for dogs to eat feces, you will begin to realize that it’s not as obscene as it appears.
Your dog eating his poop is not harmful for his general health unless the stool is contaminated with fleas, worms or other parasites that may carry bacteria and viruses. If that happens, you should take your dog to veterinarian for checkup.
Poop ingestion typically begins when dogs are young puppies. At very early stage, your puppy learns this behavior from his mother who often eats young puppy’s stool to keep the area clean and to protect them from worms and other predator that might be drawn by the scent of the stool.
Puppies primarily learn it from their mother and usually stop eating poop when they begin consuming dog food but in some cases, puppies keep this habit until they become adult. This habit can easily be reversed by proper behavioral training and feeding good quality dog food.
Now, let’s discuss these reasons in a little more details.
The primary reason for dogs to start eating their own feces is that they may not be able to digest their food properly due to the presence of low-quality ingredients in their dog food.
Dog’s digestive system is completely dependent on enzymes to breakdown nutrients from his diet but often, commercial dog food does not sit well with his stomach due to the lack of high-quality animal protein and far more carbohydrate sources (wheat, corn and soy) that are not easily digestible.
So feeding your dog a premium quality dog food not only keeps his digestion system healthy but also he will produce less waste. As a result, he will avoid consuming his stool.
Often, in city apartments where dogs have to spend the whole day alone, they tend to develop the habit of eating their poop to cure hunger due to the unavailability of real food.
In many other cases, if the dog has internal parasites and warms, then they can leach the nutrients out from the dog’s body and that will make him hungry more often than usual. To satisfy his hunger, dog may start ingesting his feces if he could not find any food.
In case of internal parasites, take your dog to the veterinarian for checkup.
Anxiety and stress often drive dogs to eat their own poop. Your dog or puppy can be stressful for variety of reason, such as changes in lifestyle, food and disturbed routine.
When his daily routine is disturbed in a way, such as a new roommate, new pet, baby, job or new home, an emotionally sensitive dog can become upset, stressed and anxious.
So it’s important for your dog’s mental health to keep a consistent daily routine and active lifestyle.
Loneliness and boredom is another major cause for poop eating behavior in dogs.
Lack of enough activity and public interaction may lead your dog to start playing with his own stool and then often advance to consuming it.
Bored dogs tend to develop far strange disturbing behaviors than active dogs. That’s why they regularly need exercise, playtime and lots of toys & puzzles to keep them occupied whole day.
At early stage, puppies learn from their mothers to keep their personal space clean. While sometimes they develop the habit of eating bodily waste when they are chained or kept into a small restricted space. Dogs often eat their poop to clean the area.
Sometimes when a owner clean dog’s stool, they misjudge the intent and try to copy their owners by eating feces as resort to their own “housekeeping” efforts.
Dogs are great students. They learn from their experience and more importantly from their owner’s reactions.
Sometimes dog owners punish or spank their dogs for defecating inside the house. This type of inappropriate/harsh punishment can make dogs eat their poop to hide the evidence and avoid being punished.
In this case, punishment is not a correct solution but appropriate training is. Also dog owners should not react in a way that is alarming to the dog when they defecate inside the house.
If you have already responded several times to your dog’s attention seeking activities, such as jumping, barking, whining etc., then it’s very good possibility that may be your dog is picking up this nasty habit to grab your attention when you are busy working or watching TV.
Even though it may not be the right way to get attention, but your dogs does not know that. Negative attention is still attention after all and your dog just wants to gain any extra attention he can get.
A proper training is the solution for this type of behavior.
This may sound weird to you but sometimes dogs eat their feces because they like the taste of it. For a dog, his feces are aromatic and tasty and often stuffed with lots of nutrients. In fact, some scientists believe it to be one of the major reasons behind this strange behavior.
Some researcher suggest adding a small amount of meat tenderizer or digestible additives, such as pumpkin, pineapple or stool deterrent supplements, into dog food can help as it makes the poop taste extremely bitter and undesirable for dogs.
Watch the video by Dr. Stephen Brammeier of Kingsbury Animal Hospital. He tries to explain why dogs either eat their own poop or another animals.
These are some of the most common reasons behind your dog’s disgusting habit of eating poop. Many times it is easier to correct this behavior by adjusting lifestyle and feeding a high-quality dog food.
However, sometimes it can be a serious behavioral or health related problem which immediate needs medical attention or this could lead to more severe health problems.
Here are several helpful tips to rid your dog of this bad habit.
Feed your dog a high-quality dog food with lots of meat protein and low carbohydrates.
Make sure your dog is getting all of the protein, fat, vitamins, minerals and other nutrients that he needs for physical and mental growth.
Make sure your dog’s eating place and poop place are far apart from one another.
Keep the yard, crate and your dog’s personal space clean.
If you’re dog defecting inside the house, clean it up immediately to avoid giving him any chance to play with the stool and eat it.
Try placing your dog on leash when you take him outside to prevent him from sniffing and ingesting other dog’s stool.
Keep him occupied with puzzles, chew toys, exercise, playtime and other activities.
Train your dog to leave things alone on your commands, such as No, ‘nah-ah-ahhh’ or ‘leave it’ and distract him with praise supported with treats.
Make sure to take him out regularly to give him chance to eliminate before placing him into his crate.
Avoid leaving him alone for long periods of time.
Instead of harsh punishments, teach in a sensible and effective approach.
If necessary, use meat tenderizer, MSG or digestible additives in dog food to make it taste bitter. This is particularly effective when your dog eat his poop in your absence as you won’t be around to stop him.
There are also products (Bitter apple sprays) available in the market that you can put on the poop itself to make it less interesting to the dog.
Take your dog to the veterinarian for regular checkup for any clinical issues and have his stool checked every 6 months.
Remember Coprophagia is a very common habit in dogs and sometimes it can be very hard to break this habit since it is self-reinforcing, but don’t let this discourage you. Patience is the key.
Try to spend more time with your dog and keep him busy with lots of different indoor and outdoor activities. In no time, your dog will be able to reverse this habit of eating poop.
Our 7 mth old chihuahua eats his poo and then he vomits it up. The eating of the poo is not the issue . It is the vomiting that scares us and sometimes he does not eat or drink for a day because the vomiting episode was so bad. I give him water with a syringe to prevent dehydration and he takes it but lays in his bed all day long and shakes / quivers. We have tried adding raw pumpkin to his food and a powder that the vet gave us to stop him from eating his poo but with no luck at all. He eats his poo if we don’t remove it as soon as he releases it. We are considering adding meat tenderizer to his food next….not sure what else to try. ????
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How to find out How many Calories to consume?
This allows you be certain of the amount you are consuming on a daily basis. In order to lose fat it is generally recommended that you are in a caloric deficit of 300-600 calories, and in order to gain muscle a surplus of 300-500 calories. Yes that means counting everything you eat.
BodyWt x13-16= Maintenance calories (includes an hr of exercise/day) This is the amount you have to eat to maintain your current weight.
It is recommended that men do not drop below 1900 cals to ensure proper nutrient intake.
BodyWt x 11-13= Maintenance calories (includes an hr of exercise/day) This is the amount you have to eat to maintain your current weight.
Think of it this way, a slice of cheese is about 100 calories and a Tbs of olive oil is 150 calories. If you don’t account for it, you may of eaten as many calories as you have burned during your workout!
Counting calories ensures that you make the most out of your investment (strength training, cardio, etc…) This will allow you to see the changes that you want in the shortest amount of time.
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What are some of the current challenges facing cryptocurrency?
Driving the next big cryptocurrency movement, UBIQUICORP will introduce two types of tokens: Transaction Tokens and Investment Tokens (formerly called Progressive Coins).
In order to realize two separate objectives – usability for real world transactions and appreciation in value as an investment vehicle – we have created two tokens, specifically designed to fulfill each purpose.
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Moral persuasion is based on the principle that there are a set of commonly agreed values or morals which everyone should obey, even if these are not written down or even particularly clear.
The general approach is to either criticize a person for taking an immoral action or making suggestions for action based on a particular moral.
When a person takes an immoral action, even if it is not a serious infraction, the moralist approach is to display outrage and demand significant reparations.
To make a moral suggestion, invoke a specific moral by mentioning it and then say that a particular course of action is required. Moral action can also be implied by simply saying that something must be done.
You just ignored her. That's terrible! Go and apologize immediately.
The president clearly does not care about his people. We must take action to depose him now.
Please help your mother clean up. It's your mess, you should be helping.
Values are general rules we adopt for helping with making decisions. These are often adopted from general social norms. Morals are stricter forms of values and are often related to the way we treat other people. Acting against morals is called immoral.
A way that moral persuasions may be identified is that they typically include modal logic of necessity, with words such as 'should', 'must', 'ought' and so on (referencing the past, this becomes 'should have', etc). Moral arguments are often assumed to supersede logic and even law, as social norms take precedence. This may be backed up with assumptive language that acts as if acting morally must obviously take priority.
The strict nature of morals means they may be invoked in persuasion as constraints that must never be broken. As such, we may indulge in moralizing as a means of persuasive speech as we invoke morals, explicitly or implicitly, as essential acts.
The implied threat of social exclusion and punishment for transgressing a moral.
The implied reward of social approval and esteem for enacting a moral (especially when the action can be personally harmful).
Criticizing immoral acts allows the moralizer to act as judge, jury and executioner, accusing a person of immorality and demanding reparations without even allowing the person to explain or excuse themselves. This position of power is so attractive, we can easily be seduced by it as we actively seek out even minor transgressions we can criticize.
A problem with moral persuasion is that it only works when everyone involved has the same morals. When one person uses a moral to persuade that another either does not follow or has an opposing moral, then conflict may well ensue. This is particularly true if the morals involved are strongly held, and even more so if a moral is held that those who do not agree must be converted or punished.
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Intro and welcome to my blog!
Hello...and a warm welcome to my blog!
This blog was created to give you an intro to my perspective on healthy eating habits, and tell you a little bit about the health benefits of the lifestyle and diet changes I made about a year ago, in July 2012.
Hopefully the articles will help you find some good recipes for cooking and baking without sugar, dairy and meat.
To give you an idea about my diet, I personally gave up meat, dairy, gluten and sugar in July 2012 to feel healthier and more energized. I was lacking energy and concentration for about 6 months and had various other health problems such as skin allergy, so I decided to research a diet called candida diet. As you know, a healthy gut flora is the key to a well functioning immune system. Of course one has to keep in mind that the body needs a balanced diet, and I strongly recommend anyone who wants to try the diet, to research this subject thoroughly.
After careful evaluation of the resources available to me, I decided to follow the recommendations of the page: www.thecandidadiet.com. I have to admit, I found a lot of controversial information about the candida diet, and what foods to eat vs. not to eat, so I decided to stick to the list on this website, as the information they provided seemed trustworthy and reliable.
After being on a strict diet for 9 months, I still felt tired and exhausted and decided to visit a naturopath who helped my mom to get rid of her candida overgrowth as well. She gave me a new list of foods, and told me that the 3 key elements of eradicating candida from your system are: following the diet, taking a very good probiotic, taking antifungal supplements.
I can email you some details of my treatment if you are interested.
I'm almost through with the new 3 month diet, and tried to stick to it, with the dedication and discipline, that I was able to preserve throughout the year. I have two more weeks to go, but I feel incredibly well and really hope that I won the fight against candida, and I want to thank all the people in my life who helped me through this year and supported my enthusiasm to stick to this diet.
I will keep you guys posted on the verdict, whether I'm candida-free, or whether I still have to be on the diet for a while, or not.
Please email me with questions, or post a comment after this article, I can't wait to hear your feedback!
Also, my plan is to give you a comprehensive overview about healthy food choices, eating habits and lifestyle changes in the upcoming articles.
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I always hear about aliasing and anti-aliasing and I know what it looks like but what I don't understand is what causes it. Is it a physical phenomenon? Or a numerical one?
If it helps to explain, I have some programming knowledge, but not in video games or graphics.
Is it a physical phenomena ? or numerical ?
This question sorta implies to me that you don't actually know what aliasing/anti-aliasing means. I mean, you say you "know what it looks like" but if you actually knew what the terms mean, you'd probably realize your question is nonsensical. Aliasing is a side-effect of how computer graphics are rendered, and computer graphics are pretty much by definition not physical phenomena.
This is an issue whenever you render the pixels in an image, whether you're drawing freehand or are writing an algorithm to calculate the pixels for a 3D polygon. It's just a side-effect of the fact that the image is a square grid of pixels. "Anti-aliasing" is when you disguise the stair-step look by blending the colors together along the edge pixels.
The accepted answer is not strictly correct, although it addresses the most common usage in computer graphics. Aliasing is a fundamental concept in signal processing and the mathematical theory of it predates computer displays. It is also not really true that "it is a side effect of the fact that pixels are square". Aliasing exists any time you discretely sample a signal at a rate below the Nyquist rate for that signal and affects digital audio as well as images and many other types of discretely sampled signals. Aliasing in computer graphics is a side effect of discrete sampling, not of the shape of the pixels.
Anti-aliasing in computer graphics is a deep and complex topic and there's a lot more to it than just edge anti-aliasing. Again, there's a lot of underlying theory from signal processing and it's an active area of research in computer graphics how to anti-alias effectively, not just for edges but also for temporal aliasing, for aliasing when reconstructing a BRDF in pixel shaders, for shadow edges and in many other areas. Mip-mapping of textures in 3D graphics is a well established anti-aliasing technique that is addressing an important problem other than edge anti-aliasing for example.
It's really a mathematical phenomenon more than a physical one but it shows up in engineering in many areas other than computer graphics. I wouldn't really describe it as a numerical phenomenon either - it's a result of discrete sampling, not of the discrete representation of numerical values on a computer, although that can cause aliasing effects too. Understanding the fundamentals of signal processing is a good foundation for understanding how aliasing manifests in computer graphics and for understanding how to go about reducing it.
Adding to the other two answers, here is a more intuitive explanation of what happens.
The grid squares represent pixels. The red polygon on the left is the shape being drawn, represented internally as a sequence of points. When it is rendered, it is converted from a list of points to a buffer of pixel colors. The discrete sampling determines which pixels are dark and which pixels are light, based on how much of the polygon covers each pixel.
To answer your question, this is a numerical/mathematical phenomenon because information about the original shape is lost due to approximation.
Anti-aliasing is when the rendering attempts to correct for aliasing by making partially-covered pixels less intense.
In signal processing field, aliasing refer to the misidentification of signal frequency. For example, due to the lack of the adequate consideration in under-sampling step it may lead to the generating errors and distortion. It can be generalized to the 2D discrete signal such as an image.
Not the answer you're looking for? Browse other questions tagged rendering antialiasing or ask your own question.
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Anti Aliasing: How to implement supersampling in OpenGL?
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Is UI anti-aliasing broken in Unity 5.6?
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In the dissipative quantum dynamics of a mesoscopic aggregate of excited two level systems (atoms) coupled to a single resonance mode of a cavity, two physical phenomena associated with superradiance appear. A pronounced emission peak on short time scales is related to the known superradiant burst of excited atoms cooperatively radiating into free space. It is followed by relaxation to a stationary state of the composite system such that for sufficiently large atom-field coupling a strongly correlated state emerges. The crossover to this state can be interpreted as the precursor of the transition from normal to superradiant phase in the thermodynamic limit of the Dicke Hamiltonian. Motivated by recent experimental activities, these features are investigated in detail for a mesoscopic number of atoms and a cavity embedded in a dissipative medium described by a damped Dicke model. We identify observables and characteristics of the quantum dynamics on shorter time scales which allow to clearly distinguish weakly correlated from strongly correlated Dicke physics.
3.2 Characteristics of the emission burst: Is it superradiance?
The Dicke model, originally developed to describe a large number N of two-level atoms interacting with a single-mode radiation field [, ] , has regained substantial interest in the last decade [, , ?, ?, ?, ?, , ] . Recent experimental realizations of Dicke physics have utilized various degrees of freedom of cold atom clouds, see e.g. [, ?, ?, ?, ?, , ] , and implementations with solid state devices have also been discussed [, ?] .
In this context, theory has contributed to a variety of aspects of the model with most of the work basically focusing on two issues, namely, the dissipative dynamics in the semiclassical limit of a large collective spin consisting of the individual atomic levels, and properties at and close to the equilibrium state in the thermodynamic limit of N→∞ and vanishing coupling to a dissipative medium. Both regimes display characteristic phenomena associated with the term superradiance: on a transient time scale, the cooperativity of the atoms may lead to superradiant light emission (burst) while thermodynamically a phase transition occurs when the atom-field coupling exceeds a certain threshold. The latter threshold captures the changeover from a regime where energy eigenstates are product states of the atoms and the field mode, to a regime where collective behavior associated with strong atom-field correlations appears (superradiant phase).
What has gained much less attention, is first the relation between these two facets, the superradiant burst and the phase transition, with respect to atom-field correlations. This issue is not only relevant experimentally [] , but also for the analysis of non-equilibrium phase transitions [] . Second, the impact of dissipation and finite size effects on the emergence of a superradiant phase have not been fully understood yet, despite their important role for mesoscopic aggregates. The purpose of this work is to contribute towards closing this gap. In particular, we will focus on the non-equilibrium dynamics of the Dicke model starting initially far from equilibrium for a moderate number of atoms (mesoscopic regime).
In fact, experimental progress for tailored superconducting circuits allows to integrate multiple artificial atoms in the form of Cooper pair boxes into micro-cavities. To maintain sufficiently long coherence times and tunability, the number of two-level systems in these devices must be kept moderate and far below the number of atoms in a cold atomic cloud. Furthermore, environmental degrees of freedom in the form of heat baths are always present in these solid state structures. Nevertheless, one may assume that signatures of Dicke physics are observable [] , at least in certain ranges of time and parameter space. Another line of research combines atomic ensembles with superconducting cavities to benefit from the long coherence times of the former and the fast tunability of the latter entities [, ?, ?] . In this case, dissipation on the solid state side, i.e. the finite photon lifetime in the micro-cavity, is the dominant mechanism and must be taken into account.
These new composite systems in turn trigger the more fundamental question, namely, to what extent the Dicke model is realized in these aggregates at all. For example, the atom-field interaction may include higher order terms in the field operator not captured in the model [, ] or couplings to residual degrees of freedom may be present (e.g. trapping loss of atoms, charge-background fluctuations in solid state systems, etc.). The Dicke model may be then justified at least on transient time scales which are short compared to typical relaxation times of the full composite system. Consequently, it may be extremely difficult, if not impossible, to monitor Dicke dynamics on long time scales and towards relaxation to a collective thermodynamic ground state. Here, we thus also address the question whether within a mesoscopic Dicke aggregate, signatures of the true phase transition are encapsulated in superradiant-type phenomena on transient time scales and in the presence of dissipation.
The paper is organized as follows. We start in section 2 with a brief discussion of the two characteristic phenomena, namely, the superradiant burst and the superradiant phase and then introduce the dissipative Dicke model explored in the sequel. In section 3, the dynamics of the photon population in the field mode (cavity) is studied in detail within the full model which is contrasted with its often used form based on a rotating wave approximation. Scaling properties of the initial radiation peak are analyzed. The issue of how to understand and monitor experimentally possible collective dynamics of atoms and cavity is addressed in section 4.
To set the stage, we briefly recap in this section the characteristics of the two well-known facets of superradiance and discuss how we envision their interplay in the proposed scenario.
A single excited atom in free space will radiate its energy isotropically in an exponential decay process. If a large number of excited atoms are brought into close proximity their decay is not described by adding the light emission rates from all the atoms independently. Instead a cooperative emission process of all atoms is established, which results in a strong, short anisotropic burst of light. This superradiant free-space burst, predicted by Dicke in 1954 [] and first experimentally observed by Skribanovitz [] , has since been extensively studied and its characteristic features are well understood (see e.g. [] for a review).
For the purpose of this paper, we will consider as defining signature of superradiance the crossover from an exponential decay for a single atom to a peak in the time-dependence of the emission rate. This peak gradually becomes more pronounced when the effective number of atoms, N, cooperating in the emission process increases (roughly speaking, N is the number of atoms within a volume, λ3ν, where λν is the wavelength of the emitted light). Due to the cooperative nature of the light emission, the peak’s height grows as N2 while its temporal width shrinks as N−1, since the integrated emission is proportional to the total initial excitation energy and, hence, to N.
The simplest theoretical description of such burst features relies on a rate model. The radiation of N excited indistinguishable two-level atoms is calculated by determining decay rates between the N+1 levels of a spin-N/2 system (which results from adding the (pseudo)spins of two-level atoms, see below) from the corresponding dipole matrix elements [] .
Figure 1: Visualizations of the potential landscape of the Dicke Hamiltonian.
(a) The Holstein-Primakoff approach maps cavity and spin degree of freedom to (displaced) bosonic operators (cf. (2) and (3)). Above a critical coupling strength two equivalent potentials V± quadratic in the corresponding (dimensionless) position variables Xa/b are found, which describe the system close to two mean field solutions (Xa,Xb)=(±√2α,∓√2β), see (5).
(b) In a ^Jx eigenbasis the Dicke Hamiltonian can be visualized as shifted parabolas for the various Mx eigenvalues, that are coupled by a ^Jz term, see (6).
where the atoms are modeled as two-level systems with identical level spacing ϵ for which collective (”large”) spin operators are introduced, ^Jz=12∑Nj=1^σzj,^J±=∑Nj=1^σ±j , ℏ=1. The collective spin couples to a common, single electromagnetic mode of frequency ω in the cavity described by bosonic operators ^a,^a† with effective coupling strength λ/√N. The latter one is conveniently introduced when the density of atoms per unit volume is fixed since then the bare coupling λ between any single atom and the atomic mode is effectively reduced with a growing number of atoms. If instead in a given experimental situation the actual density of atoms can be increased, λ grows accordingly.
The above modeling (see [] for a recent review) relies on the assumption that all atoms couple to the mode with equal strength (cf. e.g., [, ] for inhomogeneous effects) and that a loss of atoms from the collective state (e.g. due to trapping losses or external noise sources, see [] ) can be neglected on the timescales of interest. Accordingly, the collective spin operators in (1) couple only states within one J manifold of the so-called Dicke states |J,M⟩. For example, these are states with maximum angular momentum J=N/2 when the atomic system is initialized in the atomic ground state |J=N/2,M=−J⟩ or the maximally inverted state |J=N/2,M=+J⟩. The validity of the Dicke Hamiltonian for various experimental scenarios with (artificial) atoms has been widely discussed recently [, ?, ?, ?, ?, ?, ?] . Within a rotating wave approximation (RWA), where only the coupling terms ^a†^J−+^a^J+ are kept, the Hamiltonian conserves in addition to the spin magnitude J also the total number of photonic and atomic excitations ^Nex=^a†^a+^Jz+J. The full (non-RWA) Hamiltonian (1) only conserves the parity ^Π=exp(\rmiπ^Nex).
Considering the ground state of the Dicke Hamiltonian, it is immediately obvious, that there is a competition between the coupling term and the terms describing the energy of the uncoupled cavity and spin system, respectively. This competition depends on the strength of the coupling λ compared to the excitation energy for a cavity photon ω or a single spin excitation ϵ. For weak coupling, the ground state of the composite system lies close to a product state of the individual ground states of isolated cavity and isolated spin, i.e. |GSλ=0⟩:=|n=0,M=−N/2⟩. Of course, this state is a common eigenstate of the cavity number operator ^n=^a†^a and ^Jz with ^n|GSλ=0⟩=0 and ^Jz|GSλ=0⟩=−(N/2)|GSλ=0⟩.
In the opposite regime of strong coupling, one has a finite expectation value for the operator (^a†+^a)(^J++^J−) associated with a strongly correlated ground state with non-zero photon occupation and a finite number of spin excitations. In fact, in the thermodynamic limit N→∞, the Dicke Hamiltonian was shown [, ?, ] to exhibit a phase transition between a superradiant phase with macroscopic occupations in the field and the atoms and a normal phase without excitations at zero temperature. This transition occurs at a critical coupling strength λc=√ωϵ/2 [] and at λRWAc=√ωϵ for the RWA version of the Dicke Hamiltonian [, ?] .
with real-valued parameters α,β to be determined self-consistently. In the superradiant phase they are assumed to be of order O(N), corresponding to a macroscopic number of excitations.
(iii) Performing the HP approximation, a lowest order expansion in the scaled number of excitations ^b†^b/N assuming only small fluctuations around the mean field solutions. This leads to a Hamiltonian bilinear in the bosonic operators ^c,^d , while linear terms are eliminated by the self-consistent choice for the displacements (Bogoliubov transformation).
with ⟨⋅⟩SP denoting expectation values in the superradiant phase.
The respective Hamiltonians above and below the transition can also be formulated in terms of two sets of conjugate operators Xa/b,Pa/b, i.e. positions and momenta for the respective operators of cavity and atomic degrees of freedom. The position degrees of freedom Xa/b are coupled via bilinear potential terms which provides a very intuitive understanding of the emergence of a collective ground state. Namely, the principal axes are rotated with respect to the original cavity and atomic direction such that the potential surface becomes unstable in one direction when λ exceeds the critical value λc. Correspondingly, the HP approximation based on the assumption that fluctuations remain small around the fixed points α=β=0 fails. It only applies in the normal phase λ<λc sufficiently away from the phase transition, where then the Dicke model is well described by a two-dimensional harmonic oscillator potential centered around Xa=Xb=0. Instead, in the superradiant phase λ>λc the HP approach leads to two quadratic potentials V± centered around either one of the solutions, (Xa,Xb)=(±√2α,∓√2β) [see figure 1(a)].
In this latter regime, eigenstates of the model which respect the parity symmetry of the original Dicke Hamiltonian, are constructed from (anti)symmetric superpositions of the individual states of H±. In the thermodynamic limit, the HP approximation becomes exact and corresponding energy eigenvalues are double degenerate. This degeneracy is lifted for any finite number N of atoms by quantum tunneling between the wells of V±, a non-locality which cannot be captured by the HP approach. Moreover, the Hamiltonians derived within the HP approach are only suited to study the low energy sector of superradiant and normal phase, respectively. They definitely fail to describe the non-equilibrium dynamics when the system is initialized far from equilibrium, e.g. in a highly excited spin state, |n=0,M=+N/2⟩.
In a ^Jx eigenbasis, Dicke physics can then be visualized as governed by a set of shifted parabolas with nearest neighbor coupling described by the ϵ^Jz term (see figure 1). Starting for instance from the highly excited ^Jz eigenstate |n=0,M=+N/2⟩, the corresponding quantum dynamics includes Landau-Zener-type of transitions through a multitude of avoided level crossings. Details of the corresponding time evolution will be discussed elsewhere.
The above discussion brings us to the question concerning to what extent the two facets of superradiant physics can appear within a single experimental setup. Here we argue that in a minimal setting it suffices to add dissipation in the field mode and then to consider the relaxation dynamics of the compound from a maximally excited atomic state.
In the regime of very strong damping, where the level broadening in the cavity mode by far exceeds the coupling energy between atoms and cavity, cavity excitations decay quickly and the emission process resembles that of a light burst into free space. The density of states of the open cavity leads to slight modifications in the transition rates between different spin states as compared to the emission into free space though. The corresponding dynamics of the collective spin after elimination of the cavity degree of freedom has been studied in depth previously [] . However, strong damping implies that the thermodynamics of the composite system may be strongly modified by the system-bath interaction so that no conclusions can be drawn from results found for the isolated system (e.g., the existence of a phase transition). In the opposite regime of vanishing dissipation, the dynamics of the Dicke model has been studied in the past with the focus on collapse-revival features, regularity, and quantum chaos [, ?, ?] . This may give insight into collective properties of the compound but does not allow to access stationary state features for longer times.
Here, κ is the damping rate and ¯n is the thermal Bose occupation factor for an environmental photon with cavity energy ω. Note, that we employ the Lindblad dissipators derived for radiation damping of the cavity without coupling to the spin. This captures sufficiently accurately the non-equilibrium dynamics from the initial transient period up to long times where final equilibration sets in, and thus the regime where we expect the Dicke Hamiltonian to be realized in actual mesoscopic systems. Of course, for weak atom-field coupling, this modeling of dissipation is correct on all time scales.
In this section the dissipative dynamics of the field mode or, equivalently of the cavity occupation according to (7), is analyzed in detail on various time scales. The goal is to reveal the relation between and to characterize the nature of atom-field correlations during the initial and the final stage of the relaxation process.
The situation is considered where initially the compound is prepared far from its equilibrium state with all atoms in the excited state and the cavity in its ground state. We first concentrate on the zero temperature case and later on comment on finite temperature effects. As expected, the atom-cavity system starts to develop a coherent flow of excitations associated with an oscillatory pattern in typical observables such as the mean cavity occupation ⟨^n⟩ (see figure 2) and spin expectation values ⟨^Jx/y/z⟩ (not shown). Due to the leaky cavity these features are damped out so that the system finally relaxes to a stationary state. In figure 2(a) we contrast the dynamics of ⟨^n⟩ for couplings λ below and above the critical coupling λc. Results for the RWA model are included as well. In the regime below λc, both the full Dicke model and its RWA version basically coincide and predict a decay towards ⟨^n⟩=0. This is no longer the case in the regime above the critical coupling. There, the full model approaches asymptotically a finite cavity occupation in agreement with thermodynamic calculations (cf. [, ] ) and (5)) which cannot be captured by the RWA dynamics.
where the latter counter-rotating terms are absent if the RWA is employed. Hence, within RWA the Lindblad-damping term used in (8) always drives the system into a the thermal state of the bare cavity independent of the cavity-atom coupling. Consequently, no signatures of the phase transition can be found in the dynamics of the cavity occupation for the RWA model. In contrast, in the full model (⟨^a^J−⟩−⟨^a†^J+⟩) plays the role of an order parameter which is zero below and takes finite values above the phase transition. Dissipation guarantees that the compound relaxes to the correct correlated thermal state which approaches with increasing N and for T=0 the result known from the HP treatment. Of course, for any finite N the phase transition (for example ⟨^n⟩t→∞vs. λ) is smeared out.
This crucial importance of the interplay of non-RWA terms and the particular damping mechanism for the relaxation towards the correct ground state has not been fully appreciated in previous studies of dissipative Dicke models [, ] . Note though that in [] the RWA together with dissipation induced by atomic losses also yields signatures of a phase transition in the dynamics.
The benefit of the RWA is that the set of equations of motions for ⟨^n⟩ and ⟨^Jz⟩ close in the stationary limit. This is no longer the case for the full model. Analytical progress can be made, however, for the short-time dynamics starting from the initial state of fully excited spins. One finds for the initial buildup of cavity excitations in the weak damping limit ⟨^n⟩=λ2t2 (cf. figure 3) independent of the number of atoms N and valid for both the full model and for the RWA.
To elucidate further details of the dynamics and particularly make progress in understanding the nature of the first emission peak in figure 2(a), it is instructive to analyze how different eigenstates |ν⟩ of the Dicke Hamiltonian participate during different stages of the dissipative time evolution. In figure 2(b) probabilities Pν to find the system in eigenstate |ν⟩ at three different stages of the dynamics are displayed: at t=0 (left), at the ”burst time”, when the first peak in ⟨^n⟩ occurs (middle), and for long times (right) for couplings below and above the critical coupling (RWA data are included as well 1).
While in the normal regime the low energy sector is dominantly occupied throughout the time evolution, this changes drastically for λ>λc, particularly for times around the first emission peak. There, a large number of eigenstates participate substantially. Asymptotically, the probabilities Pν show a near-degeneracy of pairs of eigenstates which is reminiscent of the exact degeneracy in the thermodynamic limit according to the HP treatment. As discussed above, finite size effects induce correction terms to the HP Hamiltonians ^H± and lift their degeneracy. How many pairs of near-degenerate eigenstates occur, is a measure of the height of the barrier between the potential minima at (±√2α,∓√2β). To illustrate the appearance of these near-degenerate states, in figure 2(b) data are shown at a slightly elevated temperature ¯n=0.1. Note that one has also finite occupations in some higher lying eigenstates due to the small but finite value of the damping parameter κ. Apparently, the data for the RWA model strongly deviate from these findings for λ>λc. In particular, in the stationary limit the system is not relaxed to the lowest energy eigenstate but to a state close to the ground state of the uncoupled system.
In this subsection we will argue that the first pronounced peak in the cavity occupation of the damped Dicke model carries signatures of the superradiant free-space burst and reflects its characteristic features. These are the crossover in the time-dependence of the emission rate from an exponential decay for a single atom to a peak, where for larger N the height of the peak grows as N2, its temporal width decreases as N−1 and the integrated emission is proportional to the total initial excitation energy and, hence, to N.
These scaling properties are modified when one considers a fixed value of the parameter λ upon increasing N, the typical scenario for the analysis of the phase transition in the Dicke model. Then, the rescaled coupling constant between a single atomic excitation and the e-m field is g=λ/√N so that the emission rate due to a single excitation is reduced ∝g2=λ2/N for a larger number of atoms. Accordingly, the characteristics of the light emission are as follows (see figure 3): (i) For N independent atoms the radiation follows an exponential decay from a fixed (N-independent) value over a timescale growing linearly with N; (ii) For a superradiant burst of N cooperating atoms a peak with height ∝N and constant width ∝N0 emerges.
We can now test these signatures for the mesoscopic dissipative Dicke model (figure 3). Indeed, for λ>λc we find an increase of the height of the first peak with growing N, while its width remains basically constant. Quantitatively, for the N-dependence of peak height and width (defined here as the left-sided half width at half maximum value) the expected scaling with N and N0, respectively, is obtained (not shown). While for the results discussed so far we considered the resonant case, where the cavity energy equals the energy needed for atomic excitations, we numerically checked also the off-resonant case. It turns out that the discussed dynamical features are not very sensitive to weak de-tunings. This is in stark contrast to the purely coherent dynamics, where complex collapse-revival dynamics with domains of regularity and quantum chaos occur [, ?, ?] . We enter this dynamical range for extremely weak dissipation as well.
In conclusion, our findings strongly suggest that the physics of the free-space superradiant burst can indeed be recovered in the damped dynamics of the Dicke model for suitable parameters. In an actual experimental realization with a cold-atom cloud coupled to a superconducting stripline-cavity along the lines of [, ?] , the atom number N is orders of magnitude larger than values which can be realized in full numerical simulations. Nevertheless, the scaling characteristics of the peak will allow for a wide range of damping rates, where friction is strong enough to suppress coherent collapse-revival dynamics but weak enough to achieve prominent radiation bursts with peak cavity occupations ≫1.
Figure 3: Dynamics of the mean cavity occupation ⟨^n⟩ of the superradiant damped Dicke model (λ=1.2λc,κ/ω=1/40) for increasing number of atoms, N=5,10,15,20.
The insets contrast the emission of light into free space from N independent atoms (normal) and collective emission (superradiant) where the single-atom to field coupling is rescaled g∼1/√N as in the Dicke case. The first peak in ⟨^n⟩ has the same scaling characteristic as the superradiant burst into free space: the peak height increases linearly with N, the width is constant.
Our discussion of the dynamics of the dissipative Dicke model has so far been focused on a single observable, the mean cavity occupation ⟨^n⟩, which is certainly not the only way, to gain experimental insight into the dynamics. A more complete characterization of the cavity dynamics is offered for example by the (reduced) Wigner density of the cavity degree of freedom, which is routinely measured for stripline resonator systems (cf. [] for a recent example).
In particular, in the thermodynamic limit N→∞ of a nearly classical spin, we may expect the Wigner density, which has a simple classical interpretation, to be exceptionally suitable. One question of interest is to distinguish sub- and superradiant coupling without waiting for the relaxation of the system to its stationary state. That way, such a distinction would be immune to the danger that the long-time limit is influenced or covered by extraneous terms, not present in the Dicke Hamiltonian (e.g., non-homogenous coupling [, ] ) or additional or different damping mechanism (e.g., atom decay [] ). In fact, we find that the Wigner density dynamics shows clear signatures, reflecting the contrast between a unique mean field solution for the ground state below the critical coupling and two equivalent solutions above, already for short times and a small number of atoms.
Figure 4: Dynamics in phase space.
(a) Reduced Wigner density of the cavity above the critical coupling (λ=1.2λc): Starting from a ground state, i, the spin system excites the cavity. Occupation oscillates around, ii at t=tburst and iii at t=2tburst, and finally relaxes to two minima positions iv.
(b) shows the Husimi function of the spin degree of freedom in the stationary state, which shows a similar relaxation towards two final peaks. The spin is then directed towards two opposite points on the southern hemisphere (cf. the equator indicated by the white circle, while the south pole (¯θ=π−θ≡0, corresponding to |M=−J⟩) is in the center of the plot.
(c) shows, that the spin-reduced Mx=−J component of the cavity Wigner density relaxes to one of the stationary state positions.
In figure 4(a) we show the reduced Wigner density of the cavity (in dimensionless coordinates (Xa,Pa)) well above the critical coupling at various times. The Wigner function of the initial state at t=0 is a Gaussian peak centered at (Xa=0,Pa=0). It starts to spread out in two arms in the positive and negative Xa direction and evolves into the structure shown in figure 4(a) ii) at the time of the burst, t=tburst. A rich fine structure of complex interference patterns remains for some time, while substantial weight is assembling in two peaks (cf. (a) iii at t=2tburst). These peaks rotate around and finally slowly relax towards two final positions in phase space (cf. (a) iv), which correspond to the two equivalent solutions of the HP approximation in the N→∞ limit.
The spin-dynamics can similarly be visualized by another quasi probability-distribution, the Husimi function, relying on the concept of spin-coherent states. We show the final state’s reduced spin-Husimi function in the phase space spanned by angular variables (ϕ,θ), which indicate the ”direction” of the spin vector, in figure 4(b) for the same superradiant coupling as in (a). As for the cavity degree of freedom, we find a two peak structure for spin values corresponding to the two equivalent solutions of the HP result, cf. (5).
For subcritical coupling the initial central Gaussian peak broadens [see figure 4(d) i for λ=0.2λc and t=tburst] and re-sharpens in a breathing-type oscillation, which is damped out to relax to a final Gaussian peak centered around the unique minimum (0,0) [see figure 4(d) ii].
The long-time behavior observable in figure 4(a) iii, iv and (b) can be intuitively understood in the HP picture as damped dynamics well within the two equivalent parabolic potentials in cavity and spin variables. For the short-time behavior, however, the HP approximation is not applicable. To explain the observed splitting of the central peak into two arms [figure 4(a) ii], one can employ the representation of the Hamiltonian in a ^Jx basis yielding the shifted coupled parabolas of equation (6). Starting in the initial state, which is not a ^Jx eigenstate, each ^Jx component (which - as a cavity ground state - is a centered Gaussian in x-space) evolves in its correspondingly shifted parabola and starts to move into positive or negative x-direction. According to this picture, we expect, e.g., the Mx=±J component to start to move into positive/negative x-direction. Indeed, this behavior is observed in the corresponding spin-projected Wigner density of the cavity in figure 4(c) [same coupling and time as in (a) ii]. This argument has so far neglected the coupling between the motion in the various parabolas induced by the ^Jz term in (6), which causes transitions and interference structures, which become prominent, when the various component-wavepackets meet at a crossing of the parabolas.
The concept of a phase transition applies to a system in the thermodynamic limit (N→∞), which after a long time (t→∞) is driven to equilibrium by a vanishingly weak coupling to an environment (κ→0). For that case, the mean cavity occupation, ⟨^n⟩/J, is an order parameter for the Dicke model, i.e., an observation of its value clearly indicates whether the coupling is sub- or superradiant, λ≷λc. In our case, however, we are interested in an observable distinguishing between the weak and strong coupling case for a mesoscopic (N≳10\-−100) Dicke aggregate with finite coupling to the environment on short to intermediate time scales.
Figure 5: Observables as indicator of normal or superradiant phase.
The order parameter, ⟨^n⟩/J, of the thermodynamic phase transition does not indicate clearly, if the coupling λ is above or below the critical value λc, when the dynamics of the damped (mesoscopic, N=6) Dicke model is observed on short time-scales only (upper row).
Other observables, like the curvature of the (cavity-)Wigner density, ⟨^Πn^P2⟩, which quickly goes to positive (negative) values for coupling values below (above) the critical value, can give clearer signatures (lower row).
The left column shows the dynamics of the two observables for various values of the coupling (Color model '%) for times on the order of the inverse damping rate, κt∼1.
In the right column the value of the observables at an intermediate measurement time, κt=3 (symbols), is contrasted to its stationary limit with (κ/ω=1/10 - magenta), and without damping (black solid line). The order parameter observable, ⟨^n⟩/J (upper right panel), while distinctive in thermodynamic limit (black dashes), is less suited as an indicator of super/subradiant coupling, than other observables, like the Wigner curvature (lower right panel), which shows a distinctive sign change at (approximately) the critical coupling strength.
The latter requirement is due to the presence of additional physical processes in any actual experimental realization, which our description of the dynamics of the damped Dicke problem does not take properly into account as discussed in the Introduction.
at the center of the cavity phase space Xa=0=Pa, where the second expression containing the parity operator for the cavity degree of freedom, ^Πn, follows from the definition of the Wigner density.
Note, that this observable, which can for example be gained from a subset of measurements of the full Wigner density, is but one example of a higher order correlation function of cavity operators. Other combinations, also mixed cavity-spin correlators may be of similar or in other parameter regimes even of superior use for deducing the coupling strength from observations of the short-time dynamics. In figure 5, we demonstrate that the sign of the new observable can indeed give a clear indication of sub- or superradiant coupling strength after a short observation time of the order of the inverse damping rate, e.g., κt≤3 (lower row). In contrast, the dynamics of the order parameter of the thermodynamic case, ⟨^n⟩/J, up to this time only does not easily allow to gauge, how close to relaxation the system is (upper left panel of figure 5); even less does it show any distinguishing features around the transition from sub- to superradiant coupling (symbols in upper right panel).
Investigating the dissipative Dicke dynamics in a system where a mesoscopic cold atom cloud is coupled to a superconducting cavity, we found that two facets of superradiance physics appear. In the long term, dissipation drives the relaxation of the system towards its equilibrium state, which shows the profoundly different properties of a normal and a superradiant phase below and above the critical coupling strength. On short time scales, a peak in the cavity occupations was shown to exhibit the characteristic scaling properties of the free-space superradiant radiation burst. The radiation burst is further characterized by the participation of many eigenstates in the dynamical evolution for which non-RWA terms are of crucial importance.
To overcome issues problematic for observing the long-time limit of full relaxation, we investigated the phase-space dynamics of cavity and the atomic degree of freedom, where the reduced (quasi-)probability distributions were found to reflect the appearance of two degenerate minima in the superradiant regime. This allows to identify suitable obervables and features in their transient dynamics, which allow a clear distinction of sub- and superrradiant coupling on short time scales.
We acknowledge fruitful discussions with C. Bokas, J. Fortágh, H. Hattermann, and R. Kleiner. S. F., J. A., and B. K. thank for the kind hospitality of the Department of Physics and Astronomy at Dartmouth College. Financial support was provided by the Harris-Foundation through a distinguished visiting professorship at Dartmouth College (J.A.), the DAAD PROMOS program (S.F.), and the German Science Foundation through SFB/TRR 21.
Far below the critical coupling the probability distribution with and without RWA is obviously very similar.
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Group 1 retold Sleeping Beauty using puppets.
Group 2 decided to retell the story Sleeping Beauty.
The children chose to retell the tale The Emperor's new clothes.
This group chose to create a little twist to the story The Emperor's new clothes.
Group 6 chose to retell the story Jack and the Beanstalk.
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24 hours into this shutdown, what have we learned?
- A minority of Americans, particularly those impacted such as Federal employees are very vocal and anxious that their paychecks will be withheld, but they don't appear to necessarily blame one side over the other.
- Democrats continue to focus almost exclusively on narrative control; trying desperately to hang this around Republicans' necks while being equally stubborn.
- Republicans are defined by their infighting between the conservative majority insisting the issues are worth their stubbornness and a small fringe of moderates seeking compromise.
- A coalition of different minorities is delighted by the shutdown for various reasons, many exaggerating it to mean there is now no government or parroting the issue stances of conservative Republicans.
Without any kind of endorsement, I would say my prediction was accurate and Republicans are winning politically. Their affiliated minority is radically with them, whereas that of the Democrats is less taking sides and just wishing it would end.
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Pep Guardiola has been named as the 5th best manager of all time by @francefootball and is the only active manager in the top five. 1. Rinus Michels 2. Alex Ferguson 3. ArrigoSacchi 4. Johan Cruyff 5. Pep Guardiola.
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Truly sorry about your dog Moon, I know he meant the world to you.
so whats the joke ?
Hey up Victor, you're up early.
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Financial Recommendation From 1796 In recent years there has Matthew Linklater (simply click the up coming website) been a increase in the price of gold and this has led many people to develop an active interest in investing in gold & other precious metals. Testing - The checks could possibly be primarily based on the multi-choice format with generic; pensions, funding and retirement planning questions together with exams primarily based on particular inside procedures pertaining to the individual agency. Normally, financial funding advisers tend to break down investing into two distinct categories, and people are what are commonly referred to as indirect and direct investments.
The income comes from managing Schwab ETFs and providing companies relating to certain third get together ETFs that can be chosen for the portfolio, and from the money feature on the accounts. The whole time I used to be directing her whole account into no matter I felt most strongly was the perfect stock available in the market at the moment.
In your information, most financial advisors cost their shoppers a flat payment or a set commission on the sale on investment and related products. Gold: Its normal deviation is 20.1%, however its return is lower than 5%. When you're OK with that a lot danger, U.S. small-cap shares returned 12.9%.
There are literally 1000's of different products you'll be able to select from in order to invest or save your cash and an unbiased financial adviser may also help you decide those that are finest suited to your own personal circumstances.
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Hot chocolate; who doesn’t like to snuggle up with this hot beverage during the cold winter months? Recently, I went to Starbucks and McDonald’s and ordered their hot chocolate.This is what I thought about them.
McDonald’s hot chocolate has a good taste; it’s creamy but has a weird aftertaste to it like if you brushed your teeth than drank orange juice afterwards.. Starbucks Hot Chocolate ,on the other hand, has an amazing taste to it.It ‘s rich and creamy and doesn’t have a bad aftertaste. Starbucks also has different toppings to choose from like whipped cream, chocolate chips or chocolate syrup. McDonald’s, unfortunately, does not have the same variety of toppings.
The service at McDonald’s is fast, but sometimes you do have to wait. McDonald’s has good service, but overall Starbucks is better. Both of these resturants has WIFI,but Starbucks has pretty nice tables to sit at. Also, the smell of hot chocolate and coffee literally fills the air. Starbucks is also a very relaxing place to be in the morning unlike McDonald’s.
McDonald’s Hot Chocolate comes in a cup and a lid. It’s not really the best presentation but it does have a spill-proof lid so I give that a good review. Starbucks has amazing presentation since you can customize what your toppings are. Starbucks makes your hot chocolate look really good.
Overall I prefer Starbucks hot chocolate because you can customize what you want as the toppings and they have amazing customer service. McDonald is alright, but Starbucks has a lot more topping options and I really like toppings on my hot chocolate. Also, Starbucks is a really relaxing place to be in the morning.
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Location: Hilton of Santa Fe, 100 Sandoval Street.
How is China responding to the world economic crisis and what can those doing business in China expect? This event was a success.
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One weekend, I was in Chicago for a baseball game with some friends. We all had similar mid-morning flight times out of O’Hare the following Tuesday morning. Being a group of six, we needed a large vehicle to get us from downtown to the airport.
No problem. The doorman at the hotel hooked us up with Leo, a private driver. He called Leo and told him what time we needed to be picked up.
Being a skeptical road veteran and having been left waiting too many times for rides that didn’t show up when I needed to catch a flight, I asked the doorman for Leo’s number and called him myself to get reassurance he would show at the scheduled time. Leo said the right things and I was comfortable that he’d indeed be there. And he had the right "sound" -- a positive and upbeat voice, good articulation, solid listening skills. I was actually looking forward to meeting him.
At about 15 minutes before the scheduled time my phone buzzed. It was a text from Leo saying that he was in the black Suburban parked in front of the hotel. He also attached a selfie with him and the SUV in the background, so I knew what and who to look for. Nice.
As we walked outside, he smiled and waved to us. He ran up to my group, shook hands, and grabbed as many bags as he could so we wouldn’t have to load them in ourselves. My friends and I piled into the neat and clean vehicle.
We left early enough to give ourselves a comfortable time cushion, knowing what Chicago traffic is typically like. Things were flowing smoothly for the first five miles ... and then traffic came to a screeching halt.
The highway became a parking lot.
Now we were getting a bit worried about time. Leo remained calm. He checked his phone and informed us there was an accident a couple of miles ahead.
"Not to worry," he assured us.
With the skills of a NASCAR driver, Leo navigated through groups of cars, wiggled over to the shoulder, and got off the interstate. He told us he planned to bypass all of the trouble.
We got an up-close view of the neighborhoods of the North side of Chicago as we cruised west toward the airport. He had an uncanny way of timing the traffic lights perfectly so we rarely came to a stop.
Knowing my way around Chicago reasonably well, I asked if we were going to stay on the street we were on all the way to Rosemont, just by the airport. "No," he replied. "We're going to get back on the interstate just ahead."
Uh ... okay. I was skeptical.
But sure enough, he navigated back onto the interstate -- now moving at full speed.
I jokingly told Leo that it seemed like he knew what he was doing. He looked at me with a smirk and a wink: "That’s what 20 years of experience will do for you."
We pulled into the airport with plenty of time to spare. Leo hopped out instantly to unload the bags, thanked us profusely, and asked us to call any time we were in Chicago. I assured him I would, and tipped him heartily.
What could've gone very wrong went very right. It was a professional job, done by a true professional.
Sales professionalism includes the etiquette, characteristics, and mannerisms that are expected of salespeople. These characteristics and habits improve the ability of salespeople to communicate and build rapport with prospects.
What does this have to do with you and sales?
In my perspective, there are professional salespeople, and there are people who are merely in sales jobs.
We’ve all had what we considered "just a job" -- we showed up, we were present, we did the work with varying degrees of effort and accomplishment, we would have rather been somewhere else, and we got a paycheck for it. It was a means to an end.
On the other hand, there are professional salespeople -- just like Leo.
A salesperson finds prospective customers for their company's products and services through online research, email and phone outreach, and social media messaging. They work with these prospects to identify their challenges and needs, and ultimately find a solution. And this leads to the sale of the products or services that solve the problem.
These are a few of the key activities that professional salespeople do to sell their products or services.
Research: The salesperson learns more about the lead or prospect.
Prospect and outreach: They reach out to the prospect via email, phone, or social media.
Build rapport: Through their conversations, the sales rep builds trust with the prospect and asks questions about their goals and challenges.
Find a solution: The salesperson comes up with a custom solution to address the prospect's needs.
Close the deal: If the prospect is interested in the solution, they'll purchase the product or service with the help of the salesperson.
So, how can a salesperson become a sales professional?
A sales professional is someone who sells products or services to potential customers. They seek to solve prospects' challenges through the products they sell. Great sales professionals will have strong selling and communication skills.
Here are six characteristics of a true sales professional.
Professionals are obsessed with getting better. They are lifelong students who know they will never graduate because there’s always more to learn.
I’m amazed at how few salespeople invest in their own self-development. They spend more on coffee than on what they do every day -- the work that puts money in their pocket.
Maybe you think it's your company's job to train you. But in my opinion, whatever your company does for you in this area is a bonus. Professionals know their level of competence and subsequent achievement is ultimately up to them.
Leo took pride in the fact that he had experience, and it was obvious that he works at learning whatever it takes to get people from point A to B in the best, most efficient way.
Professionals are excellent at connecting, engaging, and carrying on a conversation.
From the first moment we spoke by phone, to the helpful text, to the banter in the car, Leo built a relationship and instilled a feeling of confidence that we picked the right person.
In sales, everything we do relies on our ability to communicate. To me, communicating isn’t blasting out mass emails. That's being a computer jockey. Instead, it’s constantly learning, practicing, and refining your sales messaging.
One thing that hasn’t changed in our hyper-technologically advanced world is that the best way to sell is still by talking to a person. Instead of whining about how hard it is to get to buyers, professionals figure out a way to get through, get in, and have meaningful conversations.
Professionals know that customers buy for their reasons, not yours. That’s why I always tell salespeople to start by first examining customers and prospects, and what they want.
Leo had this nailed. He thoroughly understood what his customers wanted and delivered on every checkbox.
It’s sad that standards have generally been lowered so much across the board to the extent that when people actually do what they say they’ll do, it’s somewhat of a surprise.
When Leo showed up 15 minutes early, I knew I was dealing with a professional. Professionals do what they say they’ll do. Period. Whatever it takes, you can count on them -- regardless of how major or minor the commitment.
You know people like this, and you also know the opposite. You can come up with names right now, can’t you?
You know professional when you see and hear it. Everything about Leo’s smile, walk, talk, and vehicle projected a professional image.
Even if all or most of your sales take place primarily over the phone, you most certainly still project your appearance through the way you sound, your voice quality, your delivery, and your equipment.
Appearance also comes through in writing. Are your emails filled with value? Or are they closer to the untargeted canned templates that so many lazy sales-job-holders blast out?
It’s said that you can tell a lot about a person based on how they react in the face of adversity.
Any warm body off the street could take an incoming call order. A real sales professional proactively puts herself in risky positions all the time, because that's where the real selling takes place. She isn’t flustered by a tough screener or deterred by prospect objections. Resistance actually prompts her to ratchet it up another gear, bear down, and gracefully employ the correct words to address the situation in a calm, conversational way.
Do you think this comes naturally to people? Nope. It comes through learning, practice, and falling and getting back up time and again.
Leo didn’t panic, beat on his steering wheel, blare his horn, or curse at other drivers when we got stalled in traffic. He calmly assessed the situation, and thought, "Okay, what do I do next?" and then did it.
I love working with real sales professionals and have had the privilege and honor of dealing with thousands over the years. The best thing about being a professional is that you decide and control if you are one or not.
If you are now, congrats -- I know you'll keep it up.
If you aren’t yet at the level you’d like to be, no worries. Make the commitment, do whatever it takes in all of the above areas, and you'll get there.
Professional sales is, in my opinion, one of the best vocations in the world. We help others and deliver massive value while being rewarded handsomely in so many ways.
It’s an elite club. I’m glad you’re part of it.
To learn more, check out these steps to build a high-performing sales team next.
Editor's note: This post originally appeared on Smart Calling Online and is republished here with permission.
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A salon stylist's mean annual salary is $27,940. Is it worth the training requirements? See real job descriptions and get the truth about career prospects to find out if becoming a salon stylist is right for you.
A career as a salon stylist can be rewarding because you can help people look and feel their best. Read on to see a list of pros and cons to see if a career in hairdressing is right for you.
Sources: *The U.S. Bureau of Labor Statistics, **Professional Beauty Association.
Stylists advise their clients on hairstyles that will best suit his or her personality and lifestyle and complement their physical appearance. Hairdressers work with both men and women and provide services such as cutting, coloring and styling. They also suggest hair products and tips for styling at home. Stylists must keep their workstations and tools neat and sanitized. Additionally, hairdressers must have good customer service skills, be creative and remain current on the latest fashion trends. Staying on your feet all day also requires a level of physical fitness and endurance.
According to the U.S. Bureau of Labor and Statistics (BLS), hairdressers earned an annual mean salary of $27,940 as of May 2014. The BLS noted that positions at high-end salons were the most competitive and employers often hired stylists with tremendous experience and potential. As of May 2014, there are over 343,000 hairdressers, stylists and cosmetologists working in the United States, half of whom were self-employed. The BLS found that due to the increase in hair treatments, employment in this field was estimated to rise by 13% from 2012-2022.
Hairdressers, barbers and cosmetologists must be licensed to work. Candidates can apply for licensure after successfully completing an approved training program. Each state administers its own licensing with many requiring periodic renewal. Licensing requirements vary by state, but most require stylists to have a high school diploma and be at least 16 years old. Exams typically consist of written and practical portions.
Hairstyling is included in the curriculum of standard cosmetology diploma and certificate programs. These programs focus on styling techniques, coloring, cutting, styling and chemicals. Some schools offer certificate programs especially for hairstyling without mention of nails or skin. While not typically required for employment, some salon stylists pursue an associate degree in cosmetology for advanced study.
In addition to having artistic talent and command of styling tools, stylists should have superb customer service skills and business acumen. They must be able to understand the styling needs of the client and translate it into a pleasing hairstyle. Having such skills can help build a steady client base, which is an indication of a successful stylist and desired by employers. Stylists also need to be effective salespeople and suggest salon products for their clients to purchase to boost a salon's revenue.
To enhance their marketability, some hairstylists seek out professional certification. While not required, a certification in a specialty area can demonstrate expertise and may attract new clients and job opportunities. For example, the American Board of Certified Haircolorists administers an exam that qualifies professionals as Board Certified Haircolorists.
A salon in Minnesota is looking for a full-time stylist to work for a nationally recognized provider of beauty services. Candidates must demonstrate seriousness in their career and enjoy working in a dynamic environment. Applicants must be willing to demonstrate the benefits of the products sold at the salon to their clients. Makeup touch-ups and scalp massages are some of the duties required.
A salon in Florida seeks a hair stylist who is also able to provide manicure, pedicure and facial services. Candidates must be team players and have a client focus. Duties also include maintaining stock and participating in continuing education.
In Boston, a boutique hair salon is seeking a licensed full-time stylist willing to work weekends. Stylists should have 2-5 years of experience, be presentable, professional and neat. An established client book is desired.
If becoming a salon stylist isn't the right fit for you, there are several careers in the beauty industry that could be of interest. Manicurists often work in salons and spas providing care to a client's hands and feet. Like a stylist, manicurists must have good customer service skills and obtain state licensure to practice. While still exposed to chemicals from the products they use, manicurists spend more of their day sitting than standing. The annual mean wage for manicurists, however, is slightly lower than that of a stylist at $22,000 as of May 2011. The job projection for manicurists and pedicurists was slightly higher than salon stylists at 17% from 2010-2020 according to the BLS.
As an additional option, you may consider becoming a skin care specialist. Like a stylist, skin care professionals spend many hours on their feet, must obtain licensure to practice and often attend cosmetology school in preparation for their career. According to the BLS, career opportunities in this field were expected to grow by 25% from 2010 to 2020, faster than average when compared with other occupations in the United States. The annual mean wage of a skin care specialist was also higher than that of a hairstylist at $32,000 as of May 2011.
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Impressionist start out with a white canvas. and use bright colors. Most paintings have visible brush strokes and the pictures are usually landscapes with small figures in the foreground. The word impressionist was originally meant to be an insult. If you look for bright colors, visitable brush strokes, simple compositions and realistic fleeding subjects you will probably be able to recognize impressionism.
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0.943242 |
Athletics is a collection of sporting events that involve competitive running, jumping, throwing, and walking. The most common types of athletics competitions are track and field, road running, cross country running, and race walking. The results of racing events are decided by finishing position (or time, where measured), while the jumps and throws are won by the athlete that achieves the highest or furthest measurement from a series of attempts. The simplicity of the competitions, and the lack of a need for expensive equipment, makes athletics one of the most commonly competed sports in the world. Athletics is mostly an individual sport, with the exception of relay races and competitions which combine athletes' performances for a team score, such as cross country. Organized athletics are traced back to the Ancient Olympic Games from 776 BC. The rules and format of the modern events in athletics were defined in Western Europe and North America in the 19th and early 20th century, and were then spread to other parts of the world. Most modern top level meetings are conducted by the International Association of Athletics Federations and its member federations. The athletics meeting forms the backbone of the Summer Olympics. The foremost international athletics meeting is the IAAF World Championships in Athletics, which incorporates track and field, marathon running and race walking. Other top level competitions in athletics include the IAAF World Cross Country Championships and the IAAF World Half Marathon Championships.
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0.999984 |
Could we stop an asteroid from hitting Earth?
Moving mountains as they free-fall through space may seem like an impossible task, but there are actually several different options for shifting an incoming asteroid’s path.
It is certainly possible, but would be a difficult and expensive task. The key would be in deflecting the asteroid away from its collision course with Earth rather than shattering it into equally dangerous debris.
This could be done by impacting it with a non-destructive projectile, simply tugging the asteroid into a different orbit with a nearby high-mass spacecraft, ablating the asteroid’s surface with a high-power laser (or a nearby nuclear explosion), or by placing small rockets on the asteroid’s surface.
All of these techniques would require at least five years to achieve, which is why early warning of potential asteroid impacts is vitally important.
Could an asteroid knock Earth out of its orbit?
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0.981242 |
Four people arrested over an assault on jockey Aidan Coleman in the weighing room at a Nottinghamshire racecourse have been bailed.
Coleman is said to have suffered ``minor injuries'' in the attack after the last race at Southwell racecourse.
Two men and a woman were arrested on suspicion of assault and criminal damage and a second woman arrested on suspicion of obstructing police.
In a brief statement, Nottinghamshire Police said all four had now been released on bail while the investigation continues.
He told The Guardian that Coleman was ``shaken'' but not seriously injured and did not think he had been singled out deliberately.
``I don't think these guys knew anything much about racing,'' he said.
Coleman is reported to have sustained a bloody nose and chipped teeth.
A Nottinghamshire Police spokesman said: ``Four people have been arrested following an assault at Southwell racecourse this afternoon.
``Officers were called at 5.23pm to reports of a man being assaulted in the weighing room.
``They attended and arrested two men and one woman on suspicion of assault and criminal damage, and another woman for obstructing police.
``The victim sustained minor injuries.
The incident took place in the weighing room at 5.10pm on Tuesday after Coleman finished last on Sawwala during the final race.
Southwell stewards said two racegoers gained entry to the jockeys' changing room.
A stewards' report said: ``The stewards held an inquiry into the circumstances surrounding an incident which occurred after the last race in the jockeys' changing rooms after two members of the public gained access, and during which a jockey sustained minor injuries.
``They interviewed jockeys Aidan Coleman, Adam Pogson and Tom Scudamore, two of the jockeys' valets, a racecourse medical officer, the clerk of the course and two members of the racecourse executive.
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0.97698 |
English: The Allianz Arena is a football stadium in the north of Munich, Germany. The two professional Munich football clubs FC Bayern München and TSV 1860 München have played their home games at Allianz Arena since the start of the 2005/06 season. Because of its shape, the stadium is nicknamed the « Schlauchboot » (inflatable boat).
Français : L'Allianz Arena est un stade de football situé au nord de Munich, en Allemagne. Les deux clubs professionnels de Munich (FC Bayern et TSV 1860) jouent leurs matches à domicile dans ce stade depuis fin 2005. Le stade est surnommé le « Schlauchboot » (canot pneumatique) en raison de son aspect.
Source [Image:Allianz arena daylight Richard Bartz.jpg], [Image:Allianz arena golden hour Richard Bartz.jpg], [Image:Allianz arena at night Richard Bartz.jpg].
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0.951419 |
Tell me how do you sleep?
Father of Mine is the third single from Everclear’s album So Much for The Afterglow. The song was written about when Art Alexakis' dad left his family when Art was young.
It peaked at #70 on the Billboard Hot 100, #4 on Billboard’s Modern Rock Tracks chart, #23 on Billboard’s Adult Top 40 chart and #24 on Billboard’s Top 40 Mainstream chart.
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0.999945 |
Making History is a quest about the restoration of the outpost north of West Ardougne and preventing it from being destroyed. During the quest, major parts of Kandarin's history and that of the Ardignas bloodline are revealed.
A secluded outpost has served the City of Ardougne for generations, playing stage to many exceptional events. Its current occupant wants to employ your skills to construct its true history before time runs out and history itself is wiped away!
Talk to Jorral in the outpost south of gnome stronghold.
To begin, speak with Jorral at the outpost located south of the Tree Gnome Stronghold, and north-west of West Ardougne. He is distraught that the outpost will soon be razed to make way for King Lathas' alchemists' lab. He shows you the outpost's "great" history through a rather humorous cutscene, and requests you to help him save the building by providing the King with the building's history and convince him to reverse his decision.
In order to save the outpost, you must gather information from various sources: Erin the silver merchant, Droalak the ghost, and Dron the warrior. This can be done in any order.
Erin's great-grandfather was stationed at the outpost, according to Jorral's records, and he thinks it might be useful to speak to Erin about it. The silver merchant can be found at his silver stall in East Ardougne.
Erin won't talk to you if you've stolen from his stall, or if you have a vial of stench in your inventory.
Speak to Erin and inform him about the potential fate of the outpost. He will instantly come up in arms, claiming that the construction of an alchemists' lab will only cause chaos. Although even his mother doesn't know about his great-grandfather too well, he provides you with his only heirloom - an enchanted key - that you may use to learn about the outpost's history.
The enchanted key reacts to a buried chest, and the closer to the chest you are, the warmer the key. The key's states go from frozen, to cold, to warm, to very hot, to burning hot, and finally to steaming hot when standing directly on top of the chest. The chest is located between the observatory and the Castle Wars lobby, and you must dig it up using either a spade or meerkats.
Use the enchanted key to unlock the chest, which contains a journal about a Zamorakian named Drozal, who took up residence in the outpost with 8 other followers and created trouble for the people of Ardougne.
Additional treasure from the enchanted key can only be obtained after the quest has been completed.
Droalak, according to Jorral, died at the outpost and might be able to provide valuable information about the outpost. He can be found wandering near the Port Phasmatys general store. Droalak tells you that he holds a scroll describing the timelines of the outpost, but he first wants your help in reconciling his wife, Melina. He had gone against his wife's wishes, and left to go to the outpost, and she refuses to forgive him for not returning to her. In order to earn her forgiveness, he requests you to present her with a strung sapphire amulet, as that was the last gift he had given her.
Melina, also dead and now a ghost, can be found in the building just east of the general store. She is elated by Droalak's gift and agrees to forgive him, before passing on from the world. Go back and deliver the message to Droalak, who hands over the scroll as a token of gratitude, and requests to inform him if the scroll was of any use.
Dron isn't directly related to the outpost, but Jorral figures that it might be fruitful to talk to him since he has studied about various wars, and the outpost must be bound to have been involved in one of them. Dron can be found in Rellekka, north-east of the market and near the musician. He has no time for "weaklings" though, and says to speak to his brother, Blanin.
Blanin is in the south-eastern part of the town, just north of the house with the dairy churn. He tells you that his brother is an introvert and only speaks to those who know him well enough. Since you have a noble intention, he provides you with information about Dron - on the condition that he must not know that you spoke with his brother.
He is 36 years, 8 months, and 21 days old.
He eats rats for breakfast.
He eats kittens for lunch.
He eats bunnies for tea.
He studies the fourth and fifth ages.
His house is on the north-east side of town.
His pet cat is named Fluffy.
5 plus 7 equals 12, but what does that have to do with anything?
His brother's name is Blanin.
When satisfied, he reminisces reading about a battle between a couple old friends, who were separated on their beliefs; one followed Zamorak, while the other favoured Saradomin. The battle culminated with both of them clashing swords atop the outpost, where they eventually woke up to the gravity of the situation and realised the error of their ways. Shortly after, they re-united and converted to Guthix followers.
Bring back all the information to Jorral, who will be ecstatic about the discoveries and promptly proceed to summarise them into a letter to be delivered to King Lathas, providing him with the suggestion of converting the outpost into a museum instead.
King Lathas can be found in his bedroom on the 1st2nd floor[UK] of the East Ardougne castle. He is surprised to learn about the outpost's rich history and writes a reply letter, in which he promises to build the outpost into a museum. The letter must then be delivered to Jorral, who will be glad that the outpost has been saved.
You can read an incomplete list of all your exploits during the quest on the bookcase at the Outpost, but cannot take it away.
You can return to Droalak in Port Phasmatys after the quest and upon learning of what happened, he will finally be at peace and will disappear. Doing so is a requirement for obtaining the master quest cape.
Complete History of Droalak ( 10) – Free Droalak after the 'Making History' quest.
Your Adventurer's Log will say "The history behind the outpost has been solved; I'd never have thought it would be so intricate!" when you complete the quest.
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0.920251 |
How much do movers in Whittier charge? The moving cost depends on the size of your home and how far you're moving.
For example, moving a 2 bedroom home to Los Angeles costs $710 - $860, to San Diego costs $850 - $1040, to San Jose costs $1250 - $1530, to San Francisco costs $1320 - $1620, to Fresno costs $1040 - $1270, etc.
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0.999236 |
For the Twenty-First Army Corps of the Union Army during the American Civil War, see XXI Corps (Union Army).
The XXI Corps was a corps of the U.S. Army during World War II. It was constituted on December 2, 1943, and activated on December 6, 1943 at Camp Polk, Louisiana. XXI Corps fought for 116 days in the European Theater of Operations, starting in the Alsace, crossing into southern Germany, and reaching into Austria. The corps was commanded in combat by Major General Frank W. Milburn as a subordinate unit of the Seventh U.S. Army.
The corps commenced combat operations January 17, 1945, during pitched battle by the U.S. Seventh Army to regain ground lost to Germany's Operation Nordwind New Year's offensive into Alsace. From 25 January until 16 February 1945, XXI Corps was attached to the French First Army and took part in bitter winter combat that ultimately collapsed the Colmar Pocket. After a period of rest, the corps returned to the front on 28 February 1945 and pushed to the edge of the Siegfried Line during the first week of March, 1945.
On 20 March 1945, after five days of combat, the corps broke through the Siegfried Line and captured Saarbrücken. Crossing the Rhine behind the U.S. XV Corps in Operation Undertone, the XXI Corps captured Würzburg on 5 April 1945, after a three-day battle marked by an assault across the Main River. Facing determined opposition, the corps fought its way into Schweinfurt on 12 April 1945, after five days of battle. Assaulting Fuerth on 18 April 1945, the corps seized Ansbach the following day and began a drive on the Danube River, over which the corps seized an intact bridge at Dillingen on 22 April 1945. On 28 April 1945, Augsburg fell to the XXI Corps, and on 1 May 1945, the corps seized Bad Tölz and captured German Field Marshal Gerd von Rundstedt. On 3 May 1945, units of the corps that included the 12th Armored Division entered Austria via Kufstein, and advanced along the Inn River as far as Worgl until met the next day by troops of the 409th Infantry Regiment of the 103rd Infantry Division radiating northeast from Innsbruck. Individual elements made it through Innsbruck and as far south as northern Italy. German forces in the area unconditionally surrendered on 6 May 1945.
Other XXI Corps elements, which included the attached 101st Airborne Division, reached Berchtesgaden from the northwest by May 8.
XXI Corps Headquarters was inactivated in Germany on 30 September 1945.
Subsequent to the Second World War, the corps was active from September 1957 until June 1970. The post-Second World War activation and inactivation occurred at Indiantown Gap Military Reservation, Pennsylvania.
^ 411th Infantry Regiment After Action Report: "Passing through advance positions of the 409th Infantry, which later pressed eastward to make contact with the XXI Corps at Worgl, elements of the 411th combat team raced more than 40 miles to seize the Brenner Pass at 0150 on May 4 without opposition. Continuing south into Italy contact was made with elements of the Fifth Army's 88th Division about eight miles south of Brenner at 1051."
This page was last edited on 16 February 2019, at 07:39 (UTC).
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0.947043 |
I'm a psychic, what needs to go into my terms and conditions?
Question: If I run a psychic business – what needs to go into my terms and conditions?
As with any business, your Terms and Conditions will require standard clauses such as those relating to payment, termination, confidentiality, etc. On top of these, for a psychic business, it is especially important that you have a detailed disclaimer clause which states that any guidance that you provide is guidance only, there are no guaranteed results, and the information should be relied on at the recipient’s own risk.
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0.998508 |
I think I scared my online guy off. How do I get him to flirt with me again?
I have been messaging this guy everyday since February through an app. I asked him for his snapchat so I could message him on there and we have been flirting, teasing each other and joking around a lot.
I decided to directly compliment him and he reciprocate back, however it was very overwhelming because he complimented me everyday and I backed off. He stopped flirting entirely and I tried to flirt with him again but its not the same. Doesn't have the same essence, he I am always initiating the flirting now and he doesn't. If I flirt he will go along with it.
I don't know if I scared him off or made him feel rejected because I was being realistic. We don't live anywhere near each other and since he was giving genuine compliments I didn't want to catch feelings and be left heartbroken. I like him and like talking to him.
I guess I want to know if I scared him off? How can I get him to flirt with me again, to reassure him? I didn't want to over-compliment him because (Ive learnt from the past) I didn't want him to get a big ego.
Sounds to me like he enjoys writing to you, but I don't think their is any future here and I suppose you both know that. It could be a number off reasons why it has died down. But I think you should just go with the flow and accept him as a pen pal. I would try not read to much in to it.
It really could be something else. Like it's time for finals soon. Or i could be that he is tired of the relationship, it isn't filling his emotional needs. Who knows?
My advice to you is to decide what it is you really want, if you just want someone to flirt with, get used to short term relations. If you want some depth, you have to stop running away the minute he starts opening up to you. Flirts come and go, he is going.
Add your answer to the question "I think I scared my online guy off. How do I get him to flirt with me again?"
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0.957047 |
Please explain the three-year bar or ten-year bar requirements for a F-1 student, if I can not keep my student status, due to the graduation and can not find job in time to change to H-1B status. Thanks.
The F or J aliens are subject to the three-year or ten-year bar, only if they fail to maintain nonimmigrant status AND the immigration official or immigration judge determines that the alien is out of status.
Once the alien is subject to the three-year bar or ten-year bar, because of their unlawful presence in the U.S. for 180 days or one year, the alien will not be able to return to the U.S. for three years or ten years once the alien leaves the U.S. The U.S. visa posts will also deny H-1B visa application.
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0.999994 |
Graffiti as an art form, which began making its appearance in the latter half of the last century. The following article provides valuable information regarding this subject.
The meaning of the term 'graffiti' is: drawings or words that are scribbled or scratched on a wall. It has been derived from the Greek word 'graphein', which means 'to write', while the term 'graffiti' itself is the plural form of 'graffito', an Italian word. This art began making its way on public walls in the latter part of the 1960s. However, graffiti as a form of unsolicited messages has existed forever, with the ancient cave paintings, dating back 40,000 years to the Upper Paleolithic era. Right from those times, drawing has always been a means of human being's deep need and desire to communicate.
Technically speaking, graffiti is a kind of art that is made on a building or wall. When graffiti drawings first started appearing, which was in New York City, the tools used to create them were usually spray paints or wide-tipped markers, which were used basically to draw 'tags', or the writer's name, and not any art as such. This was done to make themselves known all over the city. The bigger and the more colorful they could make their tag, the more attention they got. This gave rise to graffiti 'wars' springing up, with each artist trying to outdo the other in making their tag bolder and bigger. However, once these artists figured that anybody could spray on huge letters, style began making its appearance.
To people who are unfamiliar with the art, all graffiti seems the same. However, there are several distinctive styles.
Tagging: It is used mainly for displaying penmanship, and is considered as lacking in artistic form.
Blockbuster: Large sized block letters are used.
Wildstyle: Interweaving graffiti letters with designs.
Throw-Ups: This type of drawing that is done very quickly using few colors.
Bubble Letters: Large letters written in a rounded style.
Hip-Hop: Reflecting African-American culture, this is considered to be the most traditional types.
Poster: Drawings made on posters that have people's pictures on them.
Aircraft: Drawing tags on airplanes, usually on the dirt on it.
Tree: As is apparent from its name, the paintings are done or carved on trees.
Invisible: It is a purely symbolic type, like the logos made on computer microchips, which although are there, can't be seen by anybody.
Although the art of drawing graffiti letters began in the 60s, the period between 1971-1974 is generally regarded as the era when most of the pioneering work in graffiti was done, since this was the time when this form of art began spreading and getting publicity. For some of the youth of that time, it was a means through which they could vent their angst at a world, which they found oppressive, and as a way of rebelling against a society, which they thought was unjust and corrupt.
However, for others, these graffiti characters were simply a pleasurable means of expressing their creativity, just as a unique art form. Like conventional artists, they used walls as a canvas, onto which they poured their souls, their dreams, their hopes, and their fears with a spray can of bright colors. It was during 1975 to 1977, that the art of drawing graffiti reached its peak, with standards of drawing graffiti letters being established. As the 70s slipped into the 80s, being a graffiti artist became more challenging, as the authorities began clamping down harder on them, since it was considered vandalism, as most of the graffiti was made by gangsters, who were young and usually poor. This was known as the 'die-hard' era, as graffiti culture withdrew under cover.
Today's graffiti culture is referred to as the 'clean train era', as many artists are taking their art from the subway walls and the insides of train cars, into studios and galleries, with the establishment increasingly viewing it as a genuine art form. And hence, these days, some cities have provided particular areas to graffiti artists, where they are allowed to display their art. The trouble with this is that a previous work has to be painted over in order to use the space. Therefore, good artists usually do not use such spaces. One of the most important features of drawing graffiti is that each piece of art has the artist's name. Spray paint is the medium used, and there are particular techniques that have been established for drawing graffiti letters.
Different media is used to create each of these types of graffiti. Although this writing style is being legitimized, and some of it may be getting into more established forms of displaying art, such as studios and art galleries, purists are of the opinion that it is only the ones that show up on train cars and public walls are the true form.
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0.95927 |
Does Niagara Falls ever really freeze over? The answer is yes. During an extended winter cold snap a hardened crust of ice can accumulate over parts of the falls — American Falls in particular — creating an amazing, naturally formed ice sculpture that has been known to reach a thickness of 50 feet.
Neither the river nor the falls ever freeze solid. The water continues to flow beneath the ice at all times, albeit reduced to a mere trickle on rare occasions when ice jams block the river above the falls. Historically, when this blanket of ice has spanned the entire Niagara River, the phenomenon has been known as the "ice bridge." Just as you see in the photos, people used to stroll and frolic on and around the frozen falls and even walk across the ice bridge, though no one has been allowed to do the latter since 1912, when the bridge unexpectedly broke apart and three tourists died.
All of the photographs appear to be authentic, though it's unlikely any were actually taken in 1911.
The first in the set, a sepia-toned photograph found on the website of the Niagara Falls Public Library, is of unknown date and origin, according to the documentation. The image also appears on the Niagara Falls Live website, where its placement implies it was taken during the historic freeze of March 1848 when the falls actually "went dry" for a few days due to the formation of an ice dam on Lake Erie.
The second image, a panoramic view of American Falls, the infamous ice bridge, and the "ice mountain" dotted with ant-like human visitors, was reproduced a few years ago on a now-defunct website called Nostalgiaville. The photo was dated 1936. The Washington Post reported on February 2 of that year that the falls had indeed "frozen dry" for the second time in history.
"The cave of the Winds, gyved with a marvelous accumulation of ice and the great flow of water completely hidden by crystalline helmets. Such a sight is rarely to be witnessed, however for history records only three, the last time in 1886, when it is said, a million persons visited Niagara to see the marvelous exhibition of the ice king."
The fourth image, entitled "Great Mass of Frozen Spray and Ice-Bound American Falls Niagara," is also from the Niagara Falls Public Library collection, where it is cataloged as a stereo image by Underwood & Underwood. It is dated 1902.
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0.999982 |
Steve Vorenberg – Boston Prime Timers, Inc.
Hasty Pudding Theatrical: France France Revolution!
Choices: (1) Haddock, (2) Rigatoni Pasta with Meatballs, (3) Statler Chicken, (4) Pumpkin Ravioli.
Nearest T Stop: Back Bay Station on the Orange Line or Arlington Street Station on the Green Line. The Inbound № 9 Bus from Broadway Station (Red Line) stops across the street at Berkeley St. & Columbus Ave.
Cost: $28.00 per person includes Soup/Salad, Entree, Coffee/Tea, Dessert as well as Gratuity.
Your payment must be received by April 16th.
Should you need a tear sheet to send in, the most recent one can be found on the forms page.
Choices: (1) Chicken Picatta, (2) Steak Tips, (3) Shrimp and Scallop Scampi, (4) Spinach and Mushroom Ravioli.
Your payment must be received by March 19th.
Choices: (1) Chicken Parmesan, (2) Pork Chop, (3) Salmon Filet, (4) Pumpkin Ravioli.
Your payment must be received by February 19th.
Choices: (1) Baked Atlantic Haddock, (2) Meatloaf, (3) Chicken Picatta, (4) Pumpkin Ravioli.
Your payment must be received by November 21st.
Choices: (1) Steak Tips, (2) Cod Filet, (3) Statler Chicken, (4) Summer Ravioli.
Your payment must be received by October 20th.
Choices: (1) Cobb salad (with chicken), (2) Club Café beef burger, (3) Salmon filet, (4) Summer ravioli (ricotta, green beans).
Your payment must be received by September 16th.
Choices: (1) Statler Chicken, (2) Steak Tips, (3) Pan-Seared Cod, (4) Spinach and Mushroom Ravioli, (5) Margarita Pizza.
Your payment must be received by July 15th.
Choices: (1) Stuffed Pork Chops, (2) Butternut Squash Ravioli, (3) Grilled Salmon, (4) Chicken la Mirage with fries and coleslaw.
Your payment must be received by June 17th.
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0.999997 |
Not tooooo bad (I try to reserve my one star reviews for real pieces of trash), but boring, especially for what I thought was supposed to be a thriller. The plot somehow manages to be wildly implausible but also predictable. The characters made inexplicably dumb decisions in service of the plot twists. Given the limits of the material, the narrator does a good job.
In case you were worried, the dog doesn't die. He was the only character I liked.
I didn't expect this book to be so amazing!
I picked up this book when it was on sale and didn't have any expectations going in, so I was genuinely surprised when it gripped me from the very first few minutes. It covers a lot of fascinating territory that is catnip to me: extreme sports and people who push their bodies to their limits (and sometimes die in the process); diving disasters generally; the amazing science of what happens to your body under extreme pressures; brilliant or crackpot scientists (hard to tell) who believe they're on the cusp of translating dolphin speech; and the author's own journey from skeptic to free diving with sperm whales off the coast of Sri Lanka. My only complaint is that I wish it were longer--I want to spend more time in this world of people who free dive with sharks and whales.
I knocked one star off for the performance only because when the author/narrator does people's voices, they seem a little stoned. I didn't realize until writing this review that the author/narrator are the same person, though--if his narration is true-to-life and the people in his book *were* stoned when they talked to him (or at least they sounded that way), then I apologize.
And, edited to say, unless the author is also a performer (thinking of Tina Fey or Amy Poehler), I tend to find the narration in author-narrated books disappointing. Nestor does an EXCELLENT job.
BUT THEN: I checked the first book (Annihilation) out of the library this week. It's short--I made it through almost half of it in a few hours, and by that point I had been sucked in and couldn't put it down, even though it was well past midnight. It's creepy and unsettling and surprising in the best way, and I can't stop thinking about it. To say too much risks spoiling it, so I'll leave there.
In short: the audio book is not worth your time, but the written book is awesome.
I picked this up as a Daily Deal and didn't have any expectations going in, but I loved it. I listened to it in two days--as close to non-stop as sleep and work permitted.
I'm not sure why, exactly--maybe because the friendship between Abbie and Gretchen felt so authentic? Hendrix writes fully-fleshed characters with real flaws and zits, gives you enough time to get to know them and like them, and then begins the crazy stuff, a lot of which is gross, and some of which is legitimately scary.
One thing that I found hard to take, though--there is an incident of animal cruelty. You'll see it coming. If that's something that bothers you as much as it does me, you can easily avoid it by fast-forwarding for a few minutes.
Sleep Tight is a competently written thriller. A number of other reviews complain about the narrator's voice. I disagree, I thought she was quite good. Her diction reminds me a little of Hugo Weaving's character in the Matrix--some words are drawn out--but it's not distracting or unpleasant.
This book hit all my sweet spots.
ESP, conspiracy, action, a little romance, plus a narrator who is perfectly matched to the book. The plot goes in so many different directions at once, but Freedman manages to tie it all together in the end.
Docking one star, however, because nearly every woman is described in terms of her physical attractiveness (including one minor character who seems to be introduced only for us to laugh at). This is not the case for the men, and the objectification (even though by a female author) bothered me.
I was going to say that only teenage boys should read this book, but on reflection, I don't think they should, either--it's too rife with casual sexism and homophobia to make appropriate reading for anyone. And the plot makes no sense, and the characters are unrealistic (every woman is a cardboard cut-out) and/or unlikable. The narrator gamely does his best to make an unreadable book listenable, but unfortunately it's not enough to salvage this awful book.
Highly DON'T RECOMMEND -- save your credits.
Kind of a big jumble, but entertaining.
Max, the main character, is a lot of fun. The concept is great, and I liked the narration. Basically, it's a good, fun book.
But . . . it sounded very much like a first draft to me. It's more of a series of vignettes strung together by a not-very-interesting thriller-type story. Just enough details about the "bad guys" were thrown in that I thought there would be something there, but it was kept so cryptic that I couldn't bring myself to care, and I was really bored for the last two hours. It may have been a deliberate choice on the part of the author to withhold details for later books in the series, but if so, I think it was the wrong choice.
Also, for a novel about time-travelling historians, there is next to nothing about historic events. It would have been lovely to have a description of, say, the signing of the Magna Carta, or the death of King Arthur, or an explanation for Richard III and the two little princes. . . something. Anything. Instead, there are about 50 scenes describing the historians & their crews drinking and getting drunk and then drinking some more - it bothers me not at all on a moral level, but it's not very interesting to read about.
Terrific book, made even better by narration.
Kate Mulgrew knows how to tell a story. Narration can make or break a story. I listened to Joe Hill's Heart-Shaped Box a while ago and didn't like it much. The narrator did a competent job of reading the story, but he didn't *act* it, and the characters never came alive for me. Kate Mulgrew can ACT. The voices she creates for the different characters are realistic and, for Charlie Manx and Bing, absolutely chilling. She is amazing.
This book kept me awake at night wondering if N0S4A2 might be coming for me.
Love the book, disappointed by the narration.
Charlotte MacLeod is my favorite cozy mystery writer. I have read Rest You Merry and the other books in the Peter Shandy series a number of times - I wouldn't change anything.
As other reviewers have noted, the narrator pronounced certain words very strangely, to the extent that I'm not sure if he is a native English speaker. This audio book was less of a performance and more of a straight reading of the novel by someone who didn't really know what it was about or who the characters were supposed to be. You need a very particular kind of narrator for a cozy mystery that gets its color from quirky, not-quite-realistic characters and stylized, old-fashioned dialogue, and unfortunately Mr. McLain doesn't quite hit the mark.
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Not enough Medication Management Psychiatrists to choose from?
If you're looking for medication management in Seattle, these professionals provide Seattle medication management services. They include psychiatrists in Seattle, psychiatric nurses in Seattle, psychologists and therapists and can work with children or adults in managing medications or meds.
The professionals monitor the medications a client takes to confirm that they are complying with a regimen, while also ensuring they avoid harmful drug interactions and other complications. They help patients keep track of the medications used and may create lists describing medications and their dosages. These lists can be provided to patients to help them track their drugs and understand why various meds are being prescribed. Seattle Medication management may also include reminding patients about whether or not drugs need to be taken with food, and warning patients about potential side effects of medications such as fatigue, hunger, or altered level of consciousness. Antidepressants, psychiatric medications and psychotropics in Seattle, must be prescribed by a doctor (MD) ,although the management of medication in Seattle can be handled by a broader group of professionals (e.g. Seattle psychiatric nurses and [ GEO] psychopharmacologists) appropriately licensed for their level of care.
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Who is the Fidelity PM who topped the rankings across two decades? No, it was not Peter Lynch but instead a relative little-known named Tillinghast. In an era where passive investing has put active managers into the shadows, Tillinghast is one of the few PMs at Fidelity to have relatively recently built a reputation for old-fashioned stock-picking.
Morningstar nominated Tillinghast as one of the nominees for the fund manager of the decade award for his work as PM of Fidelity Low-Priced Stock.
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In order to gain knowledge about the international trade history, you should be familiarized with the classical international trade theories. General speaking, the international trade is considered the processes that have been undertaken among the states including the processes for exchanging products, services and the whole production elements, with the aim of achieving their mutual benefits.
And that's according to rules that regulate the process of exports, imports exchange, the international movements of capitals, and the transportation of their owners among these states. In this regard, the World Trade Organization, and both the International Monetary Fund and the World Bank have been established for the completion of monetary regulatory triangle.
What are the most prominent Classical International Trade Theories?
The economists in all states have divided into two groups. As for the first group, it believes that increasing the growth rate and raising the welfare level are associated with the liberalization of foreign trade; yet, this growth is related to certain terms. Meanwhile, the second group believes that the liberalization of foreign trade under the circumstances of states division into advanced and developing states will lead to the transformation of the economic surpluses of the weak states to the advanced ones through polarization mechanism. As a consequence, several classical international trade theories have emerged, which can be summarized in the rule that the state power is measured by how money it possesses, and there's no way of getting it only through the international trade. Accordingly, the state should be involved in all the spheres of economic life regardless of the restrictions and the obstacles faced by the international trade.
It's among the oldest international trade theories. This theory is based on the trading exchange that depends on the production of commodities that are characteristics of a certain state with unlimited advantages. Yet in reality, it's can't be achieved due to the existence of a lot of developing and weak states that lack this utility in producing any commodity.
This theory defends the international specialization and the trade freedom, in addition to the removal of restrictions on the international exchange. Yet, it's also difficult to achieve this theory due to the difficulty in transforming the production elements among the states. Where, the rise in the costs of transformation processes and the technological changes lead to the lack of this relative utility in producing the commodity that a certain state enjoys.
This theory of the classical international trade theories has emerged in the middle of 19th century. Such theory has refuted all theories that have been approved previously, and focused much more on the offer. As a result, the reciprocal demand theory came to focus further on the productive capacity among the states as a replacement for production costs. In addition, the concept of the international barter ratio and the extent of demand significance in determining the ratio of international exchange have expanded. Therefore, the developing states can gain additional benefits from the advanced states due to the higher standard of their income and the hugeness of their demand. Yet in reality, the gains of the advanced and major companies are significantly greater compared to the developing states.
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A Christmas Carol is a novella by Charles Dickens. A Christmas Carol tells the story of Ebenezer Scrooge, an old miser who is visited by the ghost of his former business partner Jacob Marley and the Ghosts of Christmas Past, Present and Yet to Come. After their visits Scrooge is transformed into a kinder, gentler man.
Dickens wrote A Christmas Carol at a time when the British were examining and exploring Christmas traditions from the past, such as carols, as well as new customs such as Christmas trees. He was influenced by experiences from his own past, and from the Christmas stories of other authors, including Washington Irving and Douglas Jerrold. Dickens had written three Christmas stories prior to the novella, and was inspired to write the story following a visit to the Field Lane Ragged school, one of several establishments for London's half-starved, illiterate street children. The treatment of the poor and the ability of self-interested man redeeming himself by transforming into a more sympathetic character are the key themes of the story. There is discussion among academics as to whether this was a fully secular story, or if it is a Christian allegory.
Published on 19 December, the first edition sold out by Christmas Eve; by the end of 1844 thirteen editions had been released. Most critics reviewed the novella positively. The story was illicitly copied in January 1844; Dickens took action against the publishers, who went bankrupt, reducing further Dickens's small profits from the publication. He went on to write four other Christmas stories in subsequent years. In 1849 he began public readings of the story which proved so successful he undertook 127 further performances until 1870, the year of his death. A Christmas Carol has never been out of print and has been translated into several languages; the story has been adapted many times for film, stage, opera and other media.
With A Christmas Carol, Dickens captured the zeitgeist of the mid-Victorian revival of the Christmas holiday. He has been acknowledged as an influence on the modern Western observance of Christmas and inspired several aspects of Christmas, such as family gatherings, seasonal food and drink, dancing, games and a festive generosity of spirit.
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How is "sscanf()" used in C++?
sscanf() is an I/O function that is used to read the data from an array. The return value is equal to the number of variables that is assigned. The value is zero if no fields were assigned, EOF indicates that an error has occurred prior to the first argument.
The following table lists the format specifiers used by the sscanf().
In the above syntax in the format parameter the function discards the whitespace. All the non-whitespace characters except "%" are skipped, then the next character is read. The "%" indicates a format specifier. The following table lists the format specifier used with "sscanf" function.
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Purchasing a resale property in Spain There are various taxes and costs associated with the purchase of property which will add approximately another 10% to the purchase price. Costs of purchasing.
The transfer tax, is levied at 8% of the purchase price when it is lower than 400,000 euros, 9% when the purchase price is from 400,000 euros to 700,000 euros and 10% from 700,000 euros upwards.
There is another tax to be paid on a property purchase is the “arbitriosobre el incremento del valor de losterrenos”, this is the municipal tax charged on the increase in the value of the land since its last sale, using the value of the land as the taxable base which tends to be always lower than the market value. The land is officially revalued periodically for this purpose.This tax may be paid by either the vendor or the buyer, as agreed between the parties.
Since1999, the “plusvalia” tax can be charged directly against the property itself, meaning that should the vendor be liable, and “forget” to pay it, then liability for payment will pass to the new buyer.
The notary fees are fixed by an official scale and the fee varies according to the size of the land, the size of the dwelling and its value. Land registry fees this will be a similar amount to the notary fees, and relates to the entry of the property in the land registry.
This will be a similar amount to the notary fees, and relates to the entry of the property in the land registry (“Registro de la Propiedad”).
It is highly recommended to appoint a legal representative as early as possible in the purchase process. Your lawyer will explain to you the legalities involved in the purchase and also carry out the due diligences on the property, including advising you of any debts, provide you with an estimate of the annual running costs of the property and prepare all the documentation required to complete the transaction.
Upon signing necessary documentation related to the purchase if you are unable to attend, then you may grant power of attorney to your legal representative or to another third party. The power of attorney would list all the duties that can be carried out by the third party, which may include buying and selling property, opening and administering bank accounts, applying for and accepting a mortgage, representing you with respect to utility companies and the tax authorities etc. The power of attorney would be signed before a notary public in Spain, and should cost approximately 60 euros. Should you not be able to visit a notary public in Spain and need to formalise the power of attorney in your home country, the procedure is different. Your lawyer will prepare the document in Spanish and English, and this will need to be signed before a notary public in your home country and then provided with the “Hague Apostille” at the Foreign and Commonwealth Office in London. Some notaries will take care of this process too. More information on the procedure can be obtained from their website: www.fcogov.uk.
Once you have decided on a property you wish to purchase, you will need to pay over an initial deposit/reservation fee to ensure that the property is taken off the market. The fee may be placed with the real estate agency or with your lawyer. A corresponding “offer and reservation document” should be signed upon making the payment, indicating the basic terms of the purchase, i.e. the price, details of the vendor and buyer, details of the property, and the date by which the “private purchase contract” should be signed.
The private purchase contract (PPC) will then be signed approximately 7-10 days after payment of the initial deposit/reservation fee, and once due diligences have been carried out on the property. Normally a 10% deposit would be paid; however, this may vary according to the vendor’s wishes. The contract will stipulate all the terms and conditions of the sale, including the final date by which the title deeds must be signed and final payment made, and this will then give the buyer time either to obtain a mortgage or get together the money required to complete the balance. Should the buyer fail to complete the sale by the final date, the buyer would lose the deposit. On the other hand, should the seller decide to pull out of the sale, or should the seller find another buyer who offers to pay more, then the original buyer has the right to claim back twice the amount of the deposit.
It is important to note that should you require a mortgage in Spain, this will add approximately another 2% to 3% to the purchase costs. For a non-resident buyer, the mortgage is usually limited to around 70% to 75% of the valuation of the property. Once the mortgage is approved by the Spanish bank, the bank will issue a binding offer which can be compared with other bank’s offers.
Apart from checking the legalities of the property, your lawyer will also check that all running cost and local tax payments are up to date. This will also enable your lawyer to advise you of the approximate annual running cost of the property.
The “EscrituraPublica” or Title Deed” is the final document of the sale process and is signed between the buyer and vendor when the final balance due on the property is collected. The signing takes place in the presence of a notary public, which makes the document legally binding. The notary public is an official of the state, and his duty is to certify that the contract has been signed, monies paid over, and that the buyer and vendor have been advised of their tax obligations. The notary public keeps the original of the document and the purchaser is issued with a second authorised copy, which is then entered in the property registry (against the payment of the stamp duty or transfer tax). This means that if the buyer loses the buyer’s copy, then the notary public can always issue another copy.
When going through the purchase process, you will come across different values which are attached to the property. It may be helpful to understand these different values!
The “catastro” office is the second form of property registration, and deals more with the exact location, physical description and boundaries. The “catastro” office is also the source of the “valor catastral”, which is the assessed value of the property used in calculation of local rates. If you are purchasing a new property this will not have been assigned a “valor catastral”, it therefore becomes the buyer’s responsibility to register the property at the “catastro” office for this tax. An existing property should already have its own “valor catastral”. The annual real estate tax IBI, charged by the municipality, will be calculated based on the “valor catastral”.
This is the value assessed by the tax authorities, and is the minimum value that should be declared on the title deed when a sale takes place.
This is the value assessed by a bank for mortgage approval purposes.
Depending on the market, a real estate agent or property valuer will give an estimate of a property’s current market value.
Your free valuation request has been sent. A Sure2sell representative will contact you soon.
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Jim has always had a deep love of sport, which lead him to pursue a career in the health and sport field. He has been working as a physiotherapist since 1993 and is currently employed by Lifecare Prahran Sports Medicine Centre.
Jim first toyed with the idea of becoming a physiotherapist at a very young age. He remembers watching a physiotherapist run across the field to help an injured player when, as a youngster, he watched the Australian cricket team playing a match on TV. "Ever since then I have been involved in sport!" says Jim.
Jim describes his job as very diverse and sometimes quite challenging. "You have to be able to get your clients back into their sporting activities as quickly and efficiently as possible."
He believes that it helps if you have excellent communication skills, enjoy talking, are willing to work around other people's schedules, and have an analytical approach to problem solving.
"But you also need to be good with your hands, have a good sense of body balance and good posture. Being ambidextrous and physically fit can be really useful too," adds Jim.
One of the most rewarding aspects of the job is actually seeing results, helping people get healthy again.
"It's also good to have a job that's so flexible. I'm not stuck in an office all day and I get the chance to work with elite sports stars and minor celebrities. The high turnover of clients makes the job really interesting as I meet new people all the time."
Jim has been the physiotherapist for the South Melbourne Soccer Club for the past three years and attends to any injuries incurred at training sessions or at matches.
Being a physiotherapist does have its downsides: "The work involves really long hours. Sometimes this means you lose your weekends."
A regular day at the Centre often involves seeing up to 25 clients and writing notes on each, calling doctors to discuss the progression of clients, conferring with other physiotherapists, designing exercise and treatment programs, and completing paper-work, and administrative duties.
Jim feels that the public is finally becoming more aware of the wide range of problems that physiotherapists can assist with - from everyday injuries, through to neurological conditions.
Physiotherapy can lead to a number of career paths. You may want to specialize in sports or manipulative physiotherapy, or you can go on to undertake research, or with experience, open your own clinic.
When asked what advice he would give to young people contemplating a career in physiotherapy, Jim responded, "Physiotherapy is a really rewarding career path. It's a real privilege to have the knowledge and ability to design programs to treat injured clients and to see them happy and healthy once again."
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Can an Atheist Join a Christian Campus Fellowship?
Apparently so, if trends at several U.S. universities are any indication. For example, a policy at Vanderbilt University that prohibits "discrimination on its campus against anyone because of sexual orientation, gender identity or gender expression" is being used to discriminate against religious groups. According to an online article in the Christian Post,1 at least four "Christian student organizations at Vanderbilt have been put on 'provisional status' for saying that the leaders of each of their respective groups are required to submit to their group's religious beliefs." Vanderbilt's Office of Religious Life emailed one group, the Christian Legal Society, to say that it was not allowed to "preclude someone from a leadership position based on religious belief. Only performance-based criteria may be used."
In other words, a nondiscrimination policy that was originally put in place to prevent discrimination by the school is now being used to disallow campus-recognized religious groups from distinguishing between practitioners and non-practitioners of their religion when choosing leaders.
At San Diego State University, although the policy against discriminating in membership or leadership on the basis of "race, religion, national origin, ethnicity, color, age, gender, marital status, citizenship, sexual orientation, or disability" exempts all "social fraternities or sororities" from the prohibition on gender discrimination, and allows non-religious groups to require their members and leaders to adhere to their beliefs, the school recently denied official campus-recognized status to Alpha Delta Chi (ADX), a Christian sorority, and to Alpha Gamma Omega (AGO), a Christian Fraternity.
Why the denials? Because both of these groups share a requirement that their members and officers adhere to specific religious beliefs, namely, those of Christianity.
Since ADX and AGO can technically still meet (can still exist) without official recognition as an on-campus student group, some may think that this is not such a big issue. However, the lack of official recognition means that neither ADX nor AGO can access the channels of communication used by other student groups to promote their views and invite new members. It also means that they can only exist informally. They are effectively segregated from normal communal aspects of campus life.
If Christian groups are prevented from choosing their own members and leaders, or from ensuring that they practice what they preach, they will have a hard time remaining effectively Christian. Thus, when nondiscrimination policies are applied as Vanderbilt and San Diego State have applied theirs, the policies become a means of undercutting or eliminating official on-campus Christian groups altogether.
Moreover, applying policies in this way plays directly into the hands of radical, non-Christian students who are more than willing to join a Christian group simply for the opportunity to seek a leadership position and gut the group from within. If they get the leadership position, they succeed; and if they don't get it, they can complain about discrimination and have the group expunged—which means they still succeed.
Apart from winning the lawsuits that have been filed to have these policy misapplications corrected, perhaps the only way to end this obvious discrimination against campus Christian groups will be to turn the tables: that is, for a Christian to seek (and be denied) a leadership position in an atheist group on a campus somewhere.
But regardless of the approach taken, we must remember that all students have a God-given right to freedom of speech, of religion, and of association.These rights are not up for a popular vote, nor are they such as can be given or whimsically taken away by chancellors, deans, and boards of regents.
1. Jeff Shapiro, "Vanderbilt's Nondiscrimination Policy May Discriminate Against Religious Groups" (September 28, 2011).
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Advice to college students, in no particular order.
-College debt. I think today's college students love paying taxes. Because college debt is a form of tax. You borrow money and in the future whatever salary you have will have portions extracted going to repaying your college debt. In sum, it's a tax, an expensive one, with interest rates.
-Cheap colleges. Before deciding what college you want to attend, you want to compare quality and the price. Some colleges are incredibly expensive, yet professors and the administration will treat students like a bag of turd. Some colleges are very cheap, and administration and professors treat their students like their best friends. Before choosing a college, first look at the price. Google cheapest college in town or in the country. You'll get a list of cheap colleges. Then, if you have time, visit the college and ask these two questions: are the professors kind and fair? Is the administration kind and fair? If the answer is no, pass. If the answer is yes, then you should go for that college.
-Skills you will need. The more knowledge you have, the better. The more people you know and who know you by name, the better. Valued skills include language skills and computer skills, and if you pick up a language or computer skill, you will want to be good at it.
-Picking up knowledge and skills. One of the common mistakes college students do, and I've done it myself, is to be too ambitious when trying to pick up knowledge and skills. You want to learn 5 languages and read 12 books a day, and want to attend 5 conferences a week and go to all the advertised parties. Learn one language at a time, read one book at a time and go to one event at a time. I say this because we tend to decide what book to read next when we've finished that book, tend to decide what skill to pick up next when we've picked up a new skill.
-Making the most out of semesters abroad. I'm surprised at how mismanaged study abroad programs are. During your study abroad, you want to spend time learning the local language, both in formal classes and in informal chats with people. You also want to pick a country you will have a long-term relationship with, otherwise it's just a waste of money.
-Extracurricular activities, competitions, awards, groups, clubs. The more of those you join, the better. You want to show your future employers that you were proactive.
-Where do you plan to work? Ideally you will have a job lined up before graduation. Or several jobs lined up before graduation. The only thing between you and a job is either bad university administration, bad professors, a bad boyfriend or girlfriend, or not having friends to discuss your future with.
-Go where you're celebrated. A lot of universities and companies celebrate mediocrity and punish intellect and ability. Those places exist. If you think of yourself as a mediocre kind of guy (I hope you don't) then you should probably choose companies where mediocrity is celebrated. If you think of yourself as a decent kind of guy, go where abilities are celebrated.
-Have fun and gain more skills. Once you get a job you will tend to constantly need to update your skills, mainly computer skills and language skills. But don't let that take all your free time!
Just my two cents. Hope you have a decent college career and success in life.
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Коды к игре Star Wars: Force Commander. Обзор игры State of War 2: Arcon. Прохождение игры Aggression: Reign over Europe. Скриншоты из игры Combat Mission: Battle for Normandy.
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0.999999 |
By confronting a devastated economy through actions such as creating the Federal Deposit Insurance Corporation, opening the Securities and Exchange Commission, suspending the gold standard, launching massive public works programs, and improving the morale of a demoralized nation through his fireside chats, First Inaugural address, and other motivational speeches, Franklin Roosevelt both lifted the spirits of Americans across the country and set the United States on a course that helped propel it out of the Great Depression.
Franklin Roosevelt did two things to set the United States on a course to propel itself out of the depression: (1) confronting a devastated economy (2) improving the morale of the demoralized country. Both these two actions and the list of steps taken to accomplish them need to be parallel. Since the first action (followed with its list of steps) is introduced with by the second action (followed with its list of steps) should also be introduced with by.
The correct insertion into the underlined portion of the sentence should begin with and launching massive since this is the third and final step in the list of actions taken to confront a devastated economy.
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What does the biggest human migration on earth look like on a map?
(CNN) — Although Lunar New Year in China doesn't officially start until February 19, the epic homecoming party began earlier this month.
Chunyun, or spring migration, is the world's largest annual human migration.
It's triggered in part by millions of Chinese workers heading to their hometowns for the holidays.
The migration lasts for 40 days -- from February 4 to March 15 this year.
Baidu, often referred to as China's version of Google, has released an interactive map tracking chunyun movements around the country.
On February 17, Beijing Capital International Airport was the most frequently used airport in the migration, followed by Guangzhou's Baiyun International Airport and Shenzhen Bao'an International Airport.
Beijing, Shanghai and Shenzhen -- major cities with significant populations of migrant workers -- have been seeing the biggest departures in the country.
Since February 11, Chongqing has welcomed the most returnees home.
The most traveled route is from Shanghai to Lu'an in Anhui Province (a 550-kilometer journey).
Some 2.8 billion trips using public transport networks are expected to be made this year.
If private vehicles are included, 3.7 billion trips in total will be made during the 40 days, an increase of 100 million trips over last year.
These trip figures equal the combined population of the Americas, Africa, Europe and Oceania, according to a report on Chinese website People.cn.
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What is the mathematical reason all regulators yield the same answer?
In physical terms it means the effect is insensitive to the detailed physics of the UV cutoff, which in realistic situation is related to the properties of the conductors used. The Wikipedia mentions that for some more complicated geometries the effect is sensitive to the cutoff, so why for the classic parallel planes example it isn't?
May I link to this other related question that I had asked sometime back - http://physics.stackexchange.com/questions/18106/zeta-function-regularization-in-qft-for-heat-kernels May be you can correlate the two discussions.
Check out Terry Tao's brilliant post on zeta function regularization here (I never understood the subject until I read this post). The short answer is that they're all computing the same thing, the (suitably defined) asymptotics of the divergent sum.
Tao is great but this is simply not a valid answer to the original question. Tao's text is pretty much purely mathematical and makes no physics (QFT, renormalization) analysis of the situation whatsoever - namely the coupling constants, counterterms or regulators, symmetries constraining the laws of physics if any, and the dependence or independence of physical observables on these things. So -1.
Although, I do not know if a general proof exists, I think that the Casimir effect of a renormalizable quantum field theory should be completely understood by means of a theory of renormalization on manifolds with boundary. The key feature is that one cannot, in general, neglect the renormalization of the coupling constants in the boundary terms. Using this strategy, Bondag and Vassilevich observed that the renormalization of the surface tension term (The full action including the surface terms is given in equation 44) provides a counterterm which cancels a divergent term in the Casimir energy of a dielectric ball which cannot be canceled by the zero point energy subtraction (as was pointed out by the same authers together with Kirsten in a a previous work). In the later work, the authers verified that the model including the surface terms is renormalizable at one loop.
Good physics answer, +1, as opposed to just cheap production of URLs to worshiped Fields medal winners who, despite their greatness, provide pretty much zero contribution to the answer to the original question, namely what is adjustable about the parameters describing these physical situations (plates vs other geometries).
One has to understand that any boundary condition (like E=0) is a solution to the coupled equations of charges and fields. So the Casimir effect is an **interaction of charges** in QFT, not just a "vacuum field effect".
Quantities we can measure in the lab are finite. We have mathematical models which, when used naively, yield infinite values for quantities that we can measure. Consider these infinite values artifacts of the specific mathematical model/tool/computation method. If one can identify ways in which a particular type of infinity consistently arises in a mathematical model/method, then one can keep track of it and "subtract if off" (i.e. renormalize it away) in a consistent manner.
If, for a particular way of calculating, infinities arises in a haphazard way ... then, there is no way to remove it in a mathematically consistent manner and you don't hear about that particular way.
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Is it possible to use rescue mode while also running in rate mode? I prefer flying in rate mode and would also like to try out the rescue function via a separate channel (channel 8).
What I am trying to accomplish is to have my three flight modes or idle up modes 1-3 programmed using rate mode only. However, when I flip the momentary switch on the Jeti the rescue mode activates until I release the switch. I have tried setting up rescue normal by setting one of the gyro modes to a negative value. The problem with that is although the rescue mode is active, the other two modes remain in heading hold mode.
Could I program a bank for rescue mode only and another bank for rate mode flying using the momentary switch?
flying in rate mode is actually quite demanding for a pilot. Are you sure you really want to fly in this mode? To make it more clear, you would be probably 1 from 100 000 of pilots, since Rate mode is quite uncomfortable for a normal helicopter.
Usually only pilots that are flying Scale models want to utilize this mode to show more natural behavior of the model.
In other words in this mode the rudder will drift constantly and you have to correct direction most of the time, especially backward flying is very tricky.
The reason I have been flying in rate mode is because I started flying in rate mode back in 1990 or so with an Xcell 60 and have always preferred to maintain the rudder myself. However, with the introduction of rescue mode on the Spirit unit, I am now feeling the need to utilize heading hold mode to make the rescue setup easier. However, I would prefer to eventually have rescue + rate mode alongside heading hold mode setup and accessible when wanted/needed.
Most of my flying is low head speed stuff and scale but when I am doing aerobatics, I have always like maintaining the rudder myself: call me weird For me, learning to fly the rudder in rate mode during any type of heli maneuver has become second nature so it really isn't much of an issue.
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0.962766 |
In mathematics, the Littlewood conjecture is an open problem (as of 2004) in Diophantine approximation, posed by J.
Conjecture: for any g in G/Γ such that Dg is relatively compact (in G/Γ), then Dg is closed.
This in turn is a special case of a general conjecture of Margulis on Lie groups.
Mathematicians believe the conjecture to be true, based only on numerical evidence and heuristic reasoning involving the probabilistic distribution of primes using Cramér's model.
Goldbachs conjecture is one of the oldest unsolved problems in number theory and in all of mathematics.
Hardy and John Littlewood) is a generalization of the twin prime conjecture.
John Edensor Littlewood (1885 - 1977) was a British mathematician.
Littlewood was born in Rochester in Kent, and studied at Cambridge University.
Hardy, and together they devised the Hardy - Littlewood conjecture, a strong form of the twin prime conjecture.
In mathematics, the Littlewood conjecture is an open problem (as of 2006) in Diophantine approximation, posed by J.
The conjecture states something about the limes inferior, and says that there is a subsequence for which the distances decay faster than the reciprocal, i.e.
He began research under the supervision of Ernest William Barnes, who suggested that he attempt to prove the Riemann hypothesis: Littlewood showed that if the Riemann hypothesis is true then the Prime Number Theorem follows and obtained the error term.
He coined Littlewood's law, which states that individuals can expect miracles to happen to them, at the rate of about one per month.
Littlewood's inequality on bilinear forms was a forerunner of the later Grothendieck tensor norm theory.
This conjecture is known as the prime k-tuple conjecture.
In the same memoir , Hardy and Littlewood conjectured, based on empirical evidence, that rho(x) <= pi(x) for x >= 2, where rho(x) is the largest number of primes that occur indefinitely often in an interval of length x.
In 1974, Hensley and Richards proved that the pi(x) conjecture is incompatible with the prime k-tuple conjecture (see for a summary of their work, and [4, problem A9]).
Mathematicians believe the conjecture to be true, based only on numerical evidence and heuristic reasoning involving the probabilistic distribution of primes.
In 1849 de Polignac made the more general conjecture that for every natural number k, there are infinitely many prime pairs which have a distance of 2k.
Hardy and John Littlewood), which is concerned with the distribution of twin primes, in analogy to the prime number theorem.
In number theory, the second Hardy-Littlewood conjecture concerns the number of primes in intervals.
This is probably false in general as it is inconsistent with the first Hardy-Littlewood conjecture, but the first violation is likely to occur for very large values of x.
Matthews, A generalisation of Artin's conjecture for primitive roots, Acta Arith.
This is part of a conjectural density formula for the number of twin primes not exceeding a given bound.
This is one factor in a formula for the number of primitive points of height not exceeding a given value on a cubic surface.
In his other work Littlewood collaborated with Raymond Paley in Fourier theory, and with Cyril Offord in combinatorial work on random sums, in developments that opened up fields still intensively studied.
Together they devised the first Hardy-Littlewood conjecture, a strong form of the twin prime conjecture, and the second Hardy-Littlewood conjecture.
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Goldbach wrote a letter to Euler dated June 7, 1742 suggesting (roughly) that every even integer is the sum of two integers p and q where each of p and q are either one or odd primes.
Goldbach's conjecture: Every even integer n greater than two is the sum of two primes.
This is probably false in general as it is inconsistent with the more likely first Hardy-Littlewood conjecture, but the first violation is likely to occur for very large values of x.
Second Hardy-Littlewood conjecture, References, Analytic number theory, Conjectures and Unsolved problems in mathematics.
There's a touch of the priesthood in the academic world, a sense that a scholar should not be distracted by the mundane tasks of day-to-day living.
The art of discovering the causes of phenomena, or true hypothesis, is like the art of decyphering, in which an ingenious conjecture greatly shortens the road.
Littlewood, J. It is true that I should have been surprised in the past to learn that Professor Hardy had joined the Oxford Group.
In mathematics, the Littlewood conjecture is a open problem (as of 2004) in Diophantine approximation, posed by J.
Einsiedler, Katok and Lindenstrauss have shown that it must have Hausdorff dimension zero; and in fact is a union of countably many compact sets of box-counting dimension zero.
A second twin prime conjecture states that adding a correction proportional to to a computation of Brun's constant ending with will give an estimate with error less than.
An extended form of this conjecture, sometimes called the strong twin prime conjecture or first Hardy-Littlewood conjecture, states that the number of twin primes less than or equal to x is asymptotically equal to where is the so-called twin primes constant.
This conjecture is a special case of the more general k-tuple conjecture (also known as the first Hardy-Littlewood conjecture), which corresponds to the set.
The Second Hardy-Littlewood Conjecture concerns the number of primes in intervals.
This is probably false in general as it is inconsistent with the first Hardy-Littlewood conjecture, but the first violation is likely to occur for very large values of x and y.
His immediate reaction was that of course the second conjecture was the true one, and he was quite surprised when I told him that he was contradicting the prevailing view among the experts.
The infinitude of prime pairs is a "very probable conjecture", "morally certain", or what have you, but the one thing it isn't is "known".
His immediate reaction was that of course the second > conjecture was the true one, and he was quite surprised when I told him > that he was contradicting the prevailing view among the experts.
The validity of the Hardy-Littlewood conjecture (2.3) is critical to our estimate (4.1) of Brun's B_4 constant and the associated error bound.
However, it would appear that a more rigorous error bound must await a deeper understanding of the subtleties in the distribution of the prime quadruplets in particular, and the prime constellations in general.
Hardy and J. Littlewood, "Some problems of 'Partitio Numerorum' III: On the expression of a number as a sum of primes," Acta Math.
Hardy and Littlewood conjecture that this sequence is infinite.
G. Hardy and J. Littlewood, "Some problems of `partitio numerorum'; III: on the expression of a number as a sum of primes," Acta Mathematica, Vol.
Conjecturally, a(n) is the largest number of primes that occurs on an infinite number of intervals of n consecutive integers.
The First Hardy-Littlewood conjecture (k-tuples conjecture) then implies that, for an infinitude of n, the interval [n+1, n+3159] includes 447 primes.
Conjecturally, a(n) = lim sup pi(x+n)-pi(x), where pi = A000720.
The prime pairs conjecture is a special case of this for the 1-tuple (2).
For example, the 3-tuple N, N+1, N+2 will assuredly have members divisible by 2 and by 3, and if N is divisible by 2, then either N or N+2 will be divisible by 4.
I find it curious that Dickson's Conjecture appeared in 1904, eighteen years previous to 1922, when (I believe) Hardy and Littlewood's article appeared.
The conjecture I will assume is a generalization of Dirichlet's primes in arithmetic progression, and is very similar to the Hardy- Littlewood conjecture.
Therefore, *if we assume the Hardy-Littlewood conjecture is true*, then there exists a set of k consecutive primes such that the sum of every two of them produces a distinct number.
D is not divisible by 67, 137, 277, or 557, so by the Hardy-Littlewood conjecture and its generalization, there are an infinite number of x values for which all four of these numbers are prime.
The study of prime numbers is part of number theory, the branch of mathematics which encompasses the study of natural numbers.
Prime numbers have been the subject of intense research, yet some fundamental questions remain such as the Riemann hypothesis or the Goldbach conjecture, which have been open for more than a century.
The problem of modeling the distribution of prime numbers is a popular subject of investigation for number theorists: When looking at individual numbers, the primes seem to be randomly distributed, but the "global" distribution of primes follows well-defined laws.
English mathematician who, in collaboration with G. Hardy, produced an acclaimed body of work, including contributions to pure mathematics and the theory of series and functions.
Littlewood became a Fellow of the Royal Society in 1915 and received the organization's Royal Medal (1929), Sylvester Medal (1943), and Copley Medal (1958).
John Edensor Littlewood at the MacTutor History of Mathematics archive.
He began research under the supervision of Ernest William Barnes, working on entire functions.
In his other work Littlewood collaborated with Raymond Paley in Fourier theory, and with Offord in combinatorial work on random sums, in developments that opened up fields still intensively studied.
See also: Littlewood's conjecture, Littlewood's three principles of real analysis, Littlewood-Offord problem.
Thomas J Engelsma has found many admissible prime tuplet patterns which will each give infinitely many counter examples if the k-tuple conjecture is true.
p(n) > 467473 it is necessary first to check the conjecture from n = 39017 to 19508 and i from 1 to 19508.
It appears conceivable (but unlikely in my opinion) that (2) is true and the second Hardy-Littlewood conjecture is false.
In particular we will give a proof of the Oppenheim conjecture (we may also present Margulis' original proof which does not rely on Ratner's theorem).
The emergence of the Lagrangian flag was shown to be a consequence of the Zorich-Kontsevich conjecture, that the Lyapunov spectrum of this cocycle is simple.
The rest of the minicourse will be devoted to proving a recent result, joint with Stephane Nonnenmacher, giving a positive (and explicit) lower bound for the entropy of the limit measures.
We further discuss the Littlewood conjecture for pairs of algebraic power series.
Citation coverage and analysis is incomplete and hit coverage and analysis is both incomplete and noisy.
B. Adamczewski and Y. Bugeaud, On the Littlewood conjecture in simultaneous Dio phantine approximation, J. London Math.
I will highlight a few steps of this proof and sketch in greater detail the connection to Littlewood's conjecture, and how to the deduce that the set of exceptions has Hausdorff dimension zero.
This conjecture was proved by Margulis using the methods of topological dynamics on homogeneous spaces of Lie group.
I give a gentle introduction to the ideas of the proof, derive a generalization of the Oppenheim conjecture for pairs consisting of linear and quadratic forms, and discuss open problems in the area.
This goes far beyond what was known earlier about Littlewood's conjecture, and spectacularly confirms the high promise of themethods of ergodic theory in studying previously intractable problems of diophantine approximation.
Okounkov gave the first proof of the celebrated Baik-Deift-Johansson conjecture, which states that the asymptotics of random partitions distributed according to the Plancherel measure coincides with that of the eigenvalues of large Hermitian matrices.
Venjakob's work applies quite generally to towers of number fields whose Galois group is an arbitrary compact p-adic Lie group (which is not, in general, commutative), and has done much to show that a rich theory is waiting to be developed.
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0.985787 |
The motion picture has always been useful for propaganda purposes, and in the United Kingdom especially they were handy tools for keeping morale up and spreading information that would be counter to the enemy's efforts, but once the Second World War was over, a curious thing happened: the propaganda movies continued. In fact, they continued well into the early nineteen-sixties, arguably beyond that as well, because now that the battles had been won there was the problem of what to do next that pressed on the authorities and public alike. The debts the war had run up were astronomical, and the nation was suffering from lack of resources and rationing, leaving many wondering what happened to the bright future they were promised once the Nazis were beaten.
Therefore the entertainment at the local picture palace was hugely important, both as a reminder of what they were suffering for, and a morale booster for time of peace, helpful when the British Empire was crumbling. There were countless British war films produced, some higher profile than others and some with a more lasting impression too, but among the most celebrated was 1955's The Dam Busters, the tale of the mission to destroy the German dams in the Ruhr Valley as conducted in 1943. This was an operation established with incredible speed, as the scientist Barnes Wallis devised his bouncing bombs and within weeks they were deployed against the targets, the bomber crews given the shortest possible time to learn the ropes.
The debate about how effective the mission was continues to this day: the Germans repaired much of the damage within months, and the leader of the British bombers Sir Arthur Harris was unconvinced it had contributed much of value to the war effort, the suspicion this was an ego trip for Wallis apparently not too far from the sceptics' minds. The film portrays him sympathetically, however, essayed by Michael Redgrave in one of his finest screen performances, though he, as a typical boffin, appears unaware of anything outside of succeeding in his inventions until the night of the raid, whereupon it all sinks in. The entire tone of the piece was one of the stereotypical stiff upper lip, but it would take a heart of stone not to have that lip tremble a little.
What made The Dam Busters so effective was that it never lost sight of the humanity behind the endeavours of the war. A Hollywood movie from the same decade would have been relentlessly gung ho, and less impressive for that, but director Michael Anderson and his team opted for a quieter, more considered approach that skilfully builds from Wallis experimenting with his model missiles in the back garden to the eventual realisation of his concept as the planes make their raid on the German constructions, at great risk to the pilots' own lives. That idea of sacrifice was not one that every war movie was prepared to land so strongly, but here we were never allowed to forget that not only the crews here, but the war dead across the world, gave up their lives for peace.
Richard Todd played the leader of the crews, Guy Gibson, the most decorated British flyer of World War II, with upbeat flair, coming across as a cliché to modern eyes, that is until Todd delivered the emotional scenes with understated importance. The real Gibson was apparently a colder, no-nonsense man, only twenty-four years old at the time of the Ruhr raid and would die in a crash before the war had ended, but as long as The Dam Busters plays on Sunday afternoon television in the British Isles, he will be remembered for his bravery and Todd's sympathetic portrayal of what we would like our war heroes to be, not some ultraviolent, jingoistic maniac, but someone who recognises the profundity of what they are asked to carry out, and does not relish it.
The film may have been an exponent of a very identifiable genre of the fifties, the sober but informative and compassionate war movie, adhering to some degree to the facts but not afraid to emphasise the derring-do should that arise, but not everyone was agreeing with that approach. Although George Lucas appropriated the Ruhr attack as a template for his finale to Star Wars, an assuredly pro-war film with little irony, during 1957 David Lean was releasing The Bridge Over the River Kwai, which despite being held up as one of the great examples of this style was far more cynical and questioning of that sacrifice its contemporaries took for granted. That would turn out to inform the new breed of conflict on the silver screen as the sixties arrived.
You could blame the popularity of Joseph Heller's 1961 novel Catch-22, which depicted World War II as an era of global insanity in humorous and tragic fashion, or more likely you could blame the crisis in Vietnam that erupted and went right out of control during that decade, but soon the younger generation who had gone to see all these flagwavers were growing cynical about the whole business of war, and Richard Lester, an American in Britain, sought to convey that in his comedy How I Won the War in 1967. Out at the same period as another scathing take on the British military class The Charge of the Light Brigade, Lester received horrified reviews that anyone should take the nobility of dying in a just war less than seriously, and the results were vilified.
Naturally, it became a cult movie, and for some in '67 it struck a chord; it could be the director made the mistake in comparing the battle against fascism of over two decades before with the far more contentious and controversial Vietnam War, yet you could not say he was failing to be provocative. Throughout his career, from the sixties to his ultimate retirement in the late eighties, Lester displayed a distrust of unquestioned heroism and romanticism, therefore setting him loose on the theatre of war was bound to cause trouble. Michael Crawford, his leading man from the no less purposefully problematic The Knack …and how to use it, was our guide, taking us through the war years of his officer character who as we quickly surmise, is a complete idiot.
An idiot who Britain won the war despite of, not because of, and the film indicates in its determinedly wacky style the top brass were less caring of the troops than using them as a means to and end, and expendable at that - on both sides of the combat. There were jokes all the way through this, but it wasn't especially funny, preferring to score points against its targets, which were as much the war movies like The Dam Busters, or In Which We Serve, or Dunkirk, as they were the international politics that drive countries to go to fight one another. With a cast including Beatle John Lennon, comedian Roy Kinnear and respected stage thespian Michael Hordern, this was as much offputting as it was captivating, hammering its points home unsubtly.
But who said an anti-war movie had to be subtle? Looking forward to such works as Spike Milligan's bestselling semi-autobiography Adolf Hitler: My Part in His Downfall, or indeed the movie version of Heller's Catch-22, or the decidedly less profound Kelly's Heroes of the early seventies, How I Won the War summed up a certain mood among the young that these days would not be a popular choice for a war project. Now, The Dam Busters plays better because it takes the cost of the situation so deadly seriously, and no matter how much Lester was employing his philosophy of smuggling serious topics into his humour, his efforts merely look disrespectful. With wars still raging across the planet, we may be more likely to blame the generals, politicians and religious leaders as Lester would have preferred, but The Dam Busters offers the opportunity to claw back some respectability, some worth, from a terrible set of circumstances, Eric Coates' classic orchestral theme and all.
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0.964538 |
Which software is the best to use to know the heat distribution.
Here is the text from Wikipedia.
High Frequency welding, also known as Dielectric Sealing or Radio Frequency Heat Sealing is a very mature technology that has been around since the 1940s. High frequency electromagnetic waves in the range of Radio Frequencies can heat certain polymers up to softening the plastics for joining. Heated plastics, under pressure weld together. Heat is generated within the polymer by the rapid reorientation of some chemicals dipoles of the polymer, which means that the heating can be localized, and the process can be continuous.
Only certain polymers, which contain dipoles can be heated by RF waves, in particular polymers with high loss power. Among these, PVC, polyamides and acetates are commonly welded with this technology. In practice, two pieces of material are placed on a table press that applies pressure to both surface areas. Dies are used to direct the welding process. When the press comes together, high frequency waves (usually 27.120 MHz) are passed through the small area between the die and the table where the weld takes place. This high frequency, radio frequency heat the plastic, that under pressure welds taking the shape of the die.
RF welding is fast and relatively easy to perform, produces a limited degradation of the polymer even welding thick layers, does not create fumes, requires a moderate amount of energy and can produces water-, air-, and bacteria-proof welds. Welding parameters are Welding Power, heating and cooling time and pressure, while temperature is generally not controlled directly.
If you used a Transient Thermal system, you would need to assign an internal heat generation thermal load to a small volume of the body, since the heat is generated by the dipoles in the plastic itself. You could slice the body and assign different values of internal heat generation.
I don't know HFSS or much more that I just read above about RF welding, so can you provide a value for internal heat generation to the sliced pieces near the die?
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0.986094 |
How do you establish a valuation for a new or startup company? The more common approaches follow.
The owner(s) sets the value based upon his prior experience with similar companies.
The initial capital is usually raised from the three F's – family, friends, and fools. The owner(s) decide how much (or little) of the company to grant these early investors in the form of a percentage of equity. For example, if this capital represents equity or a position which converts to equity at 10% of the total equity, then the overall enterprise value is 10 times the amount of the capital.
A secondary capital infusion from an outside source, often in the form of preferred shares. These infusions are classified Series A, Series B, Series C, etc. The amount of money provided to the company by each investor round is negotiated as to the initial outlay; future commitments based on performance criteria; and the equity (or conversion to common) percentage. This agreed upon equity percentage sets the overall valuation.
Based upon early Company results and financial projections, we develop a discounted cash flow model to estimate Company enterprise and per share values. This actual valuation is then compared to market transactions (outright sales of similar companies), to determine reasonable ranges of multiples for both projected revenues and EBITDA.
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0.973427 |
Please read and complete the following Non-Disclosure and Confidentiality Agreement.
That information provided on businesses is sensitive and confidential and that its disclosure to others would be damaging to the businesses.
That I will not disclose any Information regarding this business to any other person who has not also signed and dated this agreement, except to secure their advice and counsel, in which case I agree to obtain their consent to maintain such confidentiality.
“Information” shall include the fact that the business is for sale plus other data. The term Information does not include any information which is, or becomes, generally available to the public or is already in your possession.
All Information provided to review the business will be returned to Seller without retaining copies, summaries, analyses or extracts thereof in the event the review is terminated.
That I will not contact Seller’s employees, suppliers or customers except with written permission of Seller.
That, prior to finalizing an agreement to purchase a business, it is my responsibility to make an independent verification of all Information.
That, should I enter into an agreement to purchase the business Seller offers for sale, I grant to Seller the right to obtain, through standard reporting agencies, financial and credit information concerning myself or the companies or other parties I represent and understand that this information will be held confidential by Seller and will only be used for the purpose of Seller extending credit to me.
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0.997883 |
Why can't Emacs running in a terminal distinguish Ctrl+; from “;”?
This question arose from my previous question on emacs beta. In short I want to bind C-; to an Emacs functions in a terminal, but it seems that something captures this key before it reaches Emacs: Emacs thinks I pressed ;.
The obvious suspect is the terminal emulator, but I've checked many of them (xterm, gnome-terminal, terminator, terminology) and none of them works. Most probably I can exclude window manager, because in the GUI version of Emacs, the key C-; works just fine. I tried also two different shells: bash and zsh, but again without success.
Perhaps your confusion arises from not having used an actual terminal. Back when serious computers were the size of several upright refrigerators, a terminal communicated with a central computer over a serial cable using characters and characters only. The characters were part of some standardized character set, e.g. ASCII or EBCDIC, but typically ASCII. ASCII has 33 control characters and the terminal operator sent them by pressing a special key (such as DEL) or by holding down the CTRL key and pressing another key. The central computer only saw the resulting control character; it did not know what keys were pressed to produce the character.
A terminal emulation program such as xterm mimics that behavior. The terminal emulator provides a way to send all 33 ASCII control characters and Emacs will receive those characters if they are sent. But Emacs is like the central computer in the above description--- it has no way of knowing what keys were actually pressed when you run it under a terminal emulator. So if you press CTRL and semicolon, unless the terminal emulation program has mapped those keypresses to some ASCII character, Emacs will not know that anything has been typed.
Note that CTRL+; does not appear in that list. Terminals will usually just send the printable character assigned to key if CTRL+key isn't mapped to a control character. So what your terminal emulator is telling you by sending ; alone is that it doesn't know what to do when you press CTRL+;.
All this applies only if you're using a terminal or a terminal emulation program. If you're running Emacs as a native application under some window system, then Emacs has full access to the keystroke events and not just characters. So Emacs can see that you pressed CTRL and semicolon together and allow you to assign an action to that keystroke pair.
†Terminals often have function keys and arrow keys that also generate sequences of characters that include control characters. These sequences typically begin with ASCII code 27 (ESCAPE).
Terminals transmit characters (more precisely: bytes), not keys. When you press a key or a keychord like Ctrl+;, this information has to be encoded into a sequence of bytes. Keychords that represent a character, like A or Shift+A or À, are sent as that character: a, A, à (the last one being one or two bytes depending on the terminal's character encoding).
Keychords involving function keys have no corresponding character, so they are sent as escape sequences: a sequence of bytes beginning with the escape character (\e in an Emacs string, appearing as cyan ^[ if entered literally in a buffer). A few function keys have corresponding bytes which are control characters.
The keychord Ctrl+; has no standard escape sequence, so most terminal emulators generate the character ;. This loses the information that the Ctrl modifier was pressed.
In order to define a binding for Ctrl+;, you'll need to configure your terminal emulator to send a different escape sequence. I don't think you can do this with Gnome terminal (Gnome is rarely configurable). You can do it with Xterm. See Are there any linux terminals which can handle all key combinations? for instructions.
The shell that you may run in the terminal is not involved. A GUI Emacs has no problem because the GUI (X11) transmits input events in a form that encodes keys and modifiers, not as a mere sequence of characters.
See How do keyboard input and text output work? for more detailed background on how input gets from your keyboard to your application.
Not the answer you're looking for? Browse other questions tagged terminal keyboard-shortcuts emacs terminal-emulator or ask your own question.
Are there any linux terminals which can handle all key combinations?
How do I remap Caps_lock to Ctrl from inside emacs?
Open emacs from terminal like vim?
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0.986444 |
What are different types of Private Equity Funds?
Private equity funds are the pools of capital to be invested in organizations that speak to an open door for a high rate of return. They accompany a settled venture skyline, usually running from 4 to 7 years, and soon after that, the PE firms leave the speculation. Exit strategies incorporate IPOs and offer of the business to another private value firm or strategic purchaser. Institutional funds and certified financial specialists usually make up the vital source of equity funds, as they can give capital to expanded time frames. A group of investments experts from a specific PE firm raise and deal with the assets.
Venture capital funds are the groups of capital that regularly put resources into small, beginning the period and rising organizations that are relied upon to have excellent development potential yet have constrained access to different types of capital. From the perspective of small new businesses with aspiring offers and developments, VC funds are a fundamental source to raise money as they need access to obligation. From the perspective of a financial specialist, even though venture capital funds have risks from putting resources into unconfirmed developing organizations, they can create abnormal returns. Venture capital alludes to ventures made in new businesses and new organizations with practically no reputation for productivity. Funding speculations are made with the objective of producing outsized returns by recognizing and putting resources into the most profitable business and benefiting from a fruitful exit.
Core: Investments are made in generally safe/low-return systems with predictable money streams.
Core Plus: Moderate-risk/direct return interests in the core properties that require some significant worth included component.
Value Added: A medium-to-high-hazard/medium-to-exceptional yield methodology which includes the acquiring of property to enhance and offer a profit. Value-added strategies regularly apply to features that have operational or administration issues, require physical changes or experience the ill effects of capital imperatives.
Opportunistic: A high return or high-risk strategy, resourceful investments in properties require large measures of upgrades.
Growth capital funds are made in developed organizations with demonstrated plans of action that are searching for funding to grow or rebuild their operations, enter new markets, or finance a major acquisition. Commonly, these are minority speculations, and organizations that go up against development capital are more develop than venture funded organizations. Such organizations produce income and benefits that may not be sufficient to support huge expansions, acquisitions or different ventures.
While a few organizations may go up for growth capital for funding their growths, mezzanine financing is a substitute way. This comprises both obligation and value financing used to support an organization's extension. With the mezzanine financing, organizations take on debt capital that gives the moneylender the privilege to change over to a proprietorship or value enthusiasm for the organization if the credit isn't reimbursed in full and promptly.
Special circumstances finance mainly target organizations that need rebuilding, turnaround, or are in some other irregular conditions. Speculations ordinarily benefit from a change in the organization's valuation because of the extraordinary circumstance. Besides private value reserves; mutual funds likewise actualize this sort of venture.
A reserve of funds is a venture methodology whereby speculations are made in different funds as opposed to straightforwardly in securities, stocks, or bonds. By putting resources into a fund of funds, financial specialists are granted expansion and the capacity to hedge their risk by putting resources into different strategies of funds. Funds of funds might be exorbitant because financial specialists are liable to an extra layer of expenses. Along with the performance fee and management fees, financial specialists need to acquire additional costs at the FoF level.
When choosing to exit, Private equity funds firms take both of the two ways: add up to exit or fractional exit. As far as a discount exit from the business, there can be a trade deal to another purchaser, LBO by another private value firm, or an offer repurchase. As far as an incomplete exit, there could be a private arrangement, where another financial specialist buys a bit of the business. Another plausibility is corporate rebuilding, where the external financial specialists get included and enhance their position in the market by somewhat procuring the private value company's stake. At long last, corporate venturing could happen, in which the administration builds their proprietorship in the market.
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0.965047 |
What's the difference between an agency account and university-related event account?
An agency account is used to record activity performed on behalf of an external entity.
A university-related event account is used to record activity performed on behalf of the university.
For example, if XYZ company wants a UC Davis faculty member to host a conference and the company will pay for all of the expenses, then use an agency account. However, if it's an event the university is putting on, whether or not an outside entity is sponsoring some of the activity, then use a university-related event account.
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0.999997 |
It's the email, the email. What? What? The email!
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0.963463 |
The steadily increasing demand on transportation fuels calls for renewable fuel replacements. This has attracted a growing amount of research to develop advanced biofuels that have similar physical, chemical, and combustion properties with petroleum-derived fossil fuels. Early generations of biofuels, such as ethanol, butanol, and straight-chain fatty acid-derived esters or hydrocarbons suffer from various undesirable properties and can only be blended in limited amounts. Recent research has shifted to the production of branched-chain biofuels that, compared to straight-chain fuels, have higher octane values, better cold flow, and lower cloud points, making them more suitable for existing engines, particularly for diesel and jet engines. This review focuses on several types of branched-chain biofuels and their immediate precursors, including branched short-chain (C4–C8) and long-chain (C15–C19)-alcohols, alkanes, and esters. We discuss their biosynthesis, regulation, and recent efforts in their overproduction by engineered microbes.
High petroleum prices and increasing concerns over energy security and climate change are driving the development of renewable biofuels in recent years [1, 2]. Bioethanol has been commercially used as a gasoline replacement in major markets of the world. However, this early generation of biofuel has several problems, such as low energy density and high hygroscopicity, leading to storage and transportation problems . Recent development in microbial engineering has enabled the bioproduction of a suite of biofuel molecules, such as 1-butanol, isobutanol, limonene, hydrogenated farnesene, and fatty acid-derived alkanes, alkenes, alcohols, and esters [4, 5, 6, 7, 8, 9, 10, 11]. Based on the chain length or the number of carbon atoms in their molecules, biofuels can be divided into short-chain (C4-C8), medium-chain (C9-C14), and long-chain (C15–C20) fuels. Based on their chain structures, biofuels can be divided into straight-chain or branched-chain biofuels. Compared to straight-chain biofuels, their branched-chain counterparts often have better physical and combustion properties. Branched short-chain alcohols such as isobutanol and 3-methyl-1-butanol have higher octane values than their linear-chain counterparts [3, 12]. Branched long-chain fuels offer improved properties such as lower freezing point, better cold flow, and lower cloud point, compared with their straight-chain counterparts [13, 14], which are vital to practical biofuel use at low temperature and high altitude, particularly for jet fuels.
While production of straight-chain biofuels has been extensively reviewed [15, 16], this review targets recent progress in the microbial synthesis and overproduction of branched biofuels and their immediate precursors. Current branched fuels mostly contain only methyl branches. Ethyl and higher branched structures are relatively rare in nature and have not been extensively engineered for energy applications. Branched short-chain alcohols and esters, such as isopentenol, isobutanol, 2-methyl-1-butanol, and 3-methyl-1-butanol, are mostly derived from branched α-keto acids. Branched long-chain fuels are mostly derived from lipid fatty acids. These two types of biofuels are the major focus of this review. Branched medium-chain biofuels can be derived by engineering the isoprenoid pathway, which has been excellently reviewed elsewhere [16, 17] thus will not be discussed here. Medium-chain biofuels can also be biosynthesized by truncating the intermediates during lipid fatty acid biosynthesis [18, 19], which will be discussed together with short- and long-chain fuels. Among the branched long-chain fuels, the position of the branch can be either at the terminus or the middle of the chain. These two types of compounds were synthesized by different routes of the lipid metabolic pathway and thus are discussed separately. For each pathway, we briefly discuss the natural function of the branched compounds that lead to the synthesis of biofuels, followed by an introduction of the pathway, its regulation, and recent engineering efforts in the overproduction of branched biofuels. General metabolic engineering strategies to improve titers, yields, and productivities have been reviewed elsewhere and will not be discussed [20, 21, 22, 23]. Many of the advanced biofuels are in their early developmental stage; therefore, their scalable production and real-world application will not be the focus of this review.
In recent years, considerable advances have been achieved by engineering microorganisms to produce branched short-chain (C4–C8) alcohols and esters. These compounds were originally identified as flavor compounds in the food industry and are derived from branched-chain α-keto acids or amino acids via a pathway proposed by Ehrlich . Because of the broad substrate range of the enzymes in the last two steps of the Ehrlich pathway, the pathway becomes the basis for production of a wide range of branched short-chain compounds, including branched biofuels . Key genes in the Ehrlich pathway together with genes in the biosynthesis of α-keto acids have been engineered to improve titers and yields of branched short-chain compounds in various microorganisms, such as Escherichia coli , Bacillus subtilis , Saccharomyces cerevisiae and Ralstonia eutropha . Similar to straight short-chain alcohols, branched short-chain alcohols interfere with cell membrane’s function as a barrier, thus usually exhibiting cellular toxicity when produced in microbial hosts .
In the Ehrlich pathway (Fig. 1a), branched-chain amino acids (valine, leucine, and isoleucine) serve as the precursors and are first converted to the corresponding α-keto acids (3-methyl-oxopentanoic acid, 4-methyl-oxopentanoic acid and 3-methyl-oxobutyric acid) by transaminase (TA). Branched-chain α-keto acids can be also synthesized from carbohydrate feedstock, such as glucose, via pyruvate. Subsequently, these α-keto acids are decarboxylated by α-keto acid decarboxylase (KDC) to form the corresponding aldehydes (2-methylbutanal, isopentanal, and isobutanal). Finally, these aldehydes are oxidized by aldehyde dehydrogenase (ALDH) to branched short-chain fatty acids (2-methylbutyric acid, isovaleric acid, and isobutyric acid) or reduced by alcohol dehydrogenases (ADH) or aldehyde reductase (ALR) to branched short-chain alcohols (2-methylbutanol, isoamyl alcohol, and isobutanol). The alcohols can be combined with acyl-CoAs by alcohol acetyltransferases (ATFs) to form various esters.
Both pathway-specific activators and general regulatory mechanisms participate in the regulation of higher alcohol production in the context of the Ehrlich pathway (Fig. 1b).
Iaqui et al. first identified Aro80p as a pathway-specific transcriptional activator involved in the induction of ARO9 transaminase and ARO10 α-keto acid decarboxylase genes in the presence of the aromatic amino acid tryptophan, phenylalanine, and tyrosine. A WRCCGWSATTTRCCG motif in the aro10 and aro9 promoters was needed for the binding of Aro80p . Then, Lee et al. found that aro9 and aro10 transcription also requires the GATA activators (Gat1 and Gln3), which mediate the nitrogen catabolite repression by activating GATA genes in low nitrogen conditions. The result shows that Aro80p not only induces its target genes aro10 and aro9 by binding to their promoters, but also by the recruitment of the GATA activators. In addition, another activator War1p was identified to induce the transcription of the transporter Pdr12 encoding gene pdr12. The activator has a cis-acting element in the promoter of pdr12 and becomes active upon phosphorylation in response to the nonphysiological substrates benzoate and sorbate .
In addition, the culture conditions would also regulate the Ehrlich pathway. Lee et al. found that the heat shock stress was able to affect aro10 and aro9 transcription. The expression level of the aro10 and aro9 genes in an aro80 knockdown strain suggests that their transcription is activated by Aro80 under heat shock stress in S. cerevisiae. Furthermore, the Ehrlich pathway is also regulated in a carbon and nitrogen source-dependent manner. For example, constitutive overexpression of the ARO10 decarboxylase gene does not increase the 3-phenylpyruvate decarboxylase activity during growth on a medium supplemented with glucose and ammonium sulfate. However, the replacement of either the ammonium sulfate with phenylalanine or glucose with ethanol results in an obvious increase of 3-phenylpyruvate decarboxylase activity .
Current overproduction of branched short-chain biofuels is mainly focused on the optimization and/or modification of the Ehrlich pathways, the improvement of precursor pool, and the optimization of cofactor availability. S. cerevisiae has the natural ability to produce fatty alcohols. However, titers of branched short-chain biofuel in wild-type S. cerevisiae are very low [25, 36]. To enhance the flux through the Ehrlich pathway, Kondo et al. overexpressed α-keto acid decarboxylase (KDC) from Lactococcus lactis and an alcohol dehydrogenase Adh6p from S. cerevisiae (Fig. 1a). Subsequently, the acetolactate synthase Ilv2, which catalyzes the first step of the valine synthetic pathway, was overexpressed to enhance the flux to 2-keto-3-methylvalerate. Meanwhile, the pyruvate decarboxylase PDC1 was eliminated to reduce the flux from pyruvate to ethanol. The resulting strain produced isobutanol at a titer of 143 mg/L, which was 13-fold higher than that of the wild-type strain. Built upon this work, Matsuda et al. further eliminated a competing pathway by deletion of the pyruvate dehydrogenase complex LPD1 and enhanced the cellular NADPH content by overexpression of the malate dehydrogenase MAE1, reaching an isobutanol titer of 1.62 g/L.
Besides producing branched short-chain alcohols and esters from their natural pathways in S. cerevisiae, the Ehrlich pathway has also been engineered in a series of heterologous hosts that lack the Ehrlich pathway but offer other fermentative advantages. These heterologous hosts include E. coli, B. subtilis, Corynebacterium glutamicum, Brevibacterium flavum R. eutropha, and Synechococcus elongatus 7942. One common strategy is reconstruction of the Ehrlich pathway in a heterologous host via combinatorial gene overexpression and optimization by deletion of key competing genes. For example, Atsumi et al. constructed the Ehrlich pathway by expressing one of the five α-keto acid decarboxylases (Pdc6p, Aro10p and Thi3p from S. cerevisiae, KIVD from L. lactics and PDC from Clostridium acetobutylicum) along with an alcohol dehydrogenases Adh2 from S. cerevisiae to produce isobutanol in E. coli. The engineered Ehrlich pathway uses endogenous α-keto acids as precursors in E. coli, whose cellular pool was enhanced by deleting multiple competing pathways/enzymes, including an aldehyde-alcohol dehydrogenase (encoded by adhE), a lactate dehydrogenase A (encoded by ldhA), a fumarate reductase (encoded by frdAB), a regulator of fumarate and nitrate reduction (encoded by fnr), and a phosphate acetyltransferase (encoded by pta) that contributes to by-product formation. In combination with the overexpression of the ilvIHCD genes for 2-ketoisovalerate biosynthesis, isobutanol was produced at a titer of 22 g/L. Similarly, 2.62 g/L of isobutanol was produced in B. subtilis by engineering an Ehrlich pathway together with the overexpression of the acetolactate synthase genes (alsS, ilvC, and ilvD as shown in Fig. 1) responsible for the synthesis of 2-ketoisovalerate . C. glutamicum, the most widely used branched-chain amino acid producer in fermentation industry, has a natural ability to accumulate 2-ketoisovalerate and 2-keto-3-methylvalerate at high intracellular concentrations . By overexpressing an α-keto acid decarboxylase (encoded by aro10 from S. cerevisiae) and an alcohol dehydrogenase (encoded by yqhD from E. coli) and reducing the activity of the branched-chain amino acid transaminase, 3-methyl-1-butanol was produced at 2.76 g/L . The Ehrlich pathway has also been engineered in R. eutropha , leading to the production of 3-methyl-1-butanol and isobutanol at 140 mg/L using CO2 as the carbon source and electricity as reducing power, and in B. flavum , leading to the production of isobutanol, 2-methyl-1-butanol, and 3-methyl-1-butanol using duckweed as feedstock. In addition, branched short-chain alcohols can be produced in engineered cyanobacteria using CO2 as the carbon source and sunlight energy. In S. elongatus 7942, a 5-step heterologous biosynthetic pathway was engineered, leading to the production of isobutanol at 450 mg/L . Table 1 summarizes the theoretical yields of the above-mentioned biofuels, and their reported yields and titers in different hosts.
In addition, by overexpressing the endogenous alcohol acyltransferase (encoded by atf1) that catalyzes the condensation step of branched-chain alcohols with acetyl-CoA , isobutanol, 3-methyl-1-butanol, and 2-methyl-1-butanol were converted to isobutyl acetate, 3-methyl-1-butylacetate, and 2-methyl-1-butyl acetate with a titer of 260.2 mg/L, 296.1 mg/L, and 289.6 mg/L, respectively. For the biosynthesis of branched short-chain esters, Rodriguez et al. engineered E. coli using the alcohol O-acyltransferase (ATF) from S. cerevisiae. By combining different acyl-CoA molecules found in nature with various alcohol biosynthetic pathways, a multitude of esters were obtained. In particular, they achieved high-level production of isobutyl acetate from glucose (17.2 g/L). Wax ester synthase/acyl-coenzyme A: diacylglycerol acyltransferase (WS/DGAT), which catalyzes the esterification of fatty acyl-CoAs and short-chain alcohols, was also introduced into E. coli for the biosynthesis of fatty acid short-chain esters (FASE). A titer of 209 ± 2.6 mg/L FASEs, 50% of which being fatty acid branched-chain esters (FABCEs), was obtained .
Long-chain fatty acids (LCFAs) in the range of C14–C20 are the major membrane component for almost all organisms except for a few archaea species, which have isoprenoid-derived membranes . While the most common LCFAs have straight chains, some Gram-positive organisms, such as the Bacilli, Staphylococci, and Streptomycetes, produce terminally methyl-branched LCFAs as the acyl constituents of membrane lipids. The methyl branch is usually found at either the ω-2 or ω-3 position of the acyl group and is called iso- or anteiso-branched fatty acids, respectively . These terminally branched LCFAs are believed to increase the fluidity and lower the phase transition temperature of their lipid components . Similarly, branched LCFA-derived biofuels have significantly lower melting temperatures than their straight-chain counterparts, offering improved cold flow properties .
The biosynthetic pathway of terminally branched LCFAs in B. subtilis is well characterized [47, 48, 49] as shown in Fig. 2. This pathway used branched-chain α-keto acids as the precursors , which are first activated to short-chain acyl-CoAs by branched-chain α-keto acid dehydrogenases (BKD, encoded by the bkd operon). C4 and C5 branched-chain acyl-CoAs are the primer for the biosynthesis of terminally branched LCFAs, and malonyl-CoA is the chain extender of the primer. β-ketoacyl-acyl carrier protein synthase III (FabH) catalyzes the first condensation step by condensing branched-chain acyl-CoAs with malonyl-acyl carrier protein (malonyl-ACP). The resulting β-ketoacyl-ACP is then elongated through repeated cycles of reactions catalyzed by the multienzyme fatty acid type II biosynthesis system (FASII) to yield terminally branched long-chain acyl-ACPs. Thioesterase can hydrolyze long-chain acyl-ACPs to produce free terminally branched LCFAs. Depending on the α-keto acid precursor, different terminally branched LCFA species can be formed . For example, 3-methyl-oxobutyric acid can be converted to isobutyryl-CoA, which yields even-numbered iso-C14:0 and iso-C16:0 fatty acids. Precursors 4-methyl-oxopentanoic acid and 3-methyl-oxopentanoic acid will yield odd-numbered iso-branched and anteiso-branched C15:0 and C17:0 fatty acids, respectively .
The plasma membrane of some Gram-positive bacteria contains a mixture of straight- and branched-chain lipids. Cells vary the proportion of branched-chain fatty acids to modulate membrane fluidity. Thus, regulating the biosynthesis of terminally branched LCFAs become important to cell fitness. In these bacteria, at least three layers of regulation of their LCFA composition are identified: (1) control the α-keto acid precursor pools, (2) selective expression of the bkd operon, and (3) control FabH substrate preferences (Fig. 2).
The ilvB operon involved in the biosynthesis of α-keto acids is regulated by CodY, a global transcriptional repressor . Activation of CodY by guanosine triphosphate (GTP) and branched-chain amino acids allows CodY to bind to the promoter region of ilvB, leading to inhibition of α-keto acid biosynthesis . In addition, the ilvB operon can also be transcriptionally activated by CcpA in response to glucose and repressed by TnrA in response to nitrogen .
The B. subtilis bkd operon is also regulated by several factors . The promoter of the bkd operon is regulated by the sigma factor SigL, a member of the sigma 54 family. Transcription initiation from the bkd operon requires an activator protein BkdR, which interacts with an upstream activating sequence. The DNA binding activity of BkdR can be further enhanced by branched-chain amino acids as demonstrated in Pseudomonas putida, . Additionally, cold shock can effectively stabilize bkd mRNAs, increasing the content of branched-chain fatty acids .
When exposed to cold temperatures, some Gram-positive bacteria predominantly increase the proportion of low-freezing anteiso-branched LCFAs relative to iso- and straight LCFAs in its membrane . For example, the Listeria monocytogenes FabH showed a higher preference for 2-methylbutyryl-CoA, the precursor of odd-numbered anteiso-LCFAs, at 10 °C than that at 30 °C. The temperature-dependent substrate selectivity of FabH underlies the increased formation of anteiso-LCFAs during low-temperature adaptation .
Recent advances in metabolic engineering have enabled the overproduction of terminally branched LCFAs in microbial hosts that naturally do not produce branched lipids. These engineering efforts have largely expanded the capability to bioproduce advanced biofuels in microbial hosts that have more attractive features than the native host . By overexpressing the B. subtilis fabH2 and its bkd operon, a terminally branched LCFA biosynthetic pathway was first constructed in E. coli (Fig. 3) . However, the initially engineered strain only produced 2.5 mg/L of branched-chain LCFAs. Instead, a high proportion of straight-chain fatty acids were co-produced . To increase the proportion of terminally branched LCFAs in total free fatty acids, Jiang et al. replaced the acetyl-CoA-specific E. coli FabH with a branched-chain-acyl-CoA-specific FabH and found that this replacement directed the flux to the synthesis of terminally branched LCFAs and increased the terminally branched LCFAs titer by 48-fold. Later, it was found that overexpression of the bkd operon depleted the cellular lipoylation capability of the host, preventing the proper lipoylation of two E. coli native α-keto acid dehydrogenases, including the essential 2-oxoacid dehydrogenase (OADH) and the pyruvate dehydrogenase (PDH), thus inhibiting cell growth and terminally branched LCFAs production . To solve this problem, an endogenous protein lipoylation pathway was engineered (Fig. 3). This pathway contains a lipoyl (octanoyl) transferase (LipB, encoded by lipB) that transfers an octanoyl moiety from octanoyl-ACP to the E2 subunit of α-keto acid dehydrogenases and a lipoyl synthase (LipA, encoded by lipA) that inserts two sulfur atoms into the octanoyl side chain of the octanoylated E2 subunit, forming a lipoyl group. The engineered protein lipoylation pathway not only restored the function of all α-keto acid dehydrogenases, but also increased the terminally branched LCFA titer to 207 mg/L . Incorporation of the terminally branched LCFAs into the lipid membrane is expected to affect membrane fluidity and permeability, resulting in cellular stress. However, analysis of previously engineered LCFA-producing strains showed little incorporation of branched LCFAs into cell membrane .
While most Gram-positive bacteria produce both iso- and anteiso-LCFAs as a mixture, for practical applications, it is desirable to engineer strains that can specifically produce one type of terminally branched LCFAs. This has been achieved mostly by controlling the supply of α-keto acid precursors. When overexpressing the B. subtilis alsS and the E. coli ilvCD (Fig. 3), flux through 3-methyl-2-oxobutyric acid was enhanced, leading to even-chain-iso-fatty acid as the major terminally branched LCFA species (65%) . When the leuABCD operon containing a feedback-resistant mutant of leuA was overexpressed, biosynthesis of 4-methyl-2-oxopentanoic acid was enhanced (Fig. 3), making the odd-chain-iso-fatty acids the predominant terminally branched LCFA products (89%) .
In addition, anteiso-branched LCFAs were produced as the major branched LCFA species by overexpressing the Salmonella typhimurium ilvGMCD, the C. glutamicum ilvA, and the E. coli thrABC to enhance the flux through 3-methyl-oxopentanoic acids and by dynamically regulating fabH expression (Fig. 3). The resulting strain produced anteiso-branched fatty acids up to 20.4% of total free fatty acids . Overall, by engineering α-ketoacid biosynthetic pathways, compositions of terminally branched LCFAs can also be controlled.
Besides the overproduction of terminally branched LCFAs, some metabolic engineering works on the production of branched alkanes, alcohols, and esters have also been reported [7, 8]. Branched alkanes, as ideal biofuels, are structurally and chemically similar to fossil fuels. Howard et al. introduced the fatty acid reductase complex from Photorhabdus luminescens and an aldehyde decarbonylase from Nostoc punctiforme into E. coli with a terminally branched LCFA biosynthetic pathway, yielding methyl pentadecane. The results clearly demonstrate the feasibility of engineering artificial pathways for branched alkane biosynthesis in a microbial host. Branched long-chain fatty alcohols (BLFLs) in the range of C12 to C18 are more suitable as diesel fuel replacements than their straight-chain counterparts. Jiang et al. constructed and tested the efficiencies of four different biosynthetic pathways that convert branched acyl-ACPs to BLFLs in E. coli. A modular engineering approach was then used to balance the flux between α-keto acid synthesis, acyl-ACP generation, and alcohol formation. The best performing strain produced BLFLs at 350 mg/L, where 75% of the produced fatty alcohols were BLFLs. In addition, Tao et al. combined the branched short-chain alcohol and the branched LCFA biosynthetic pathways in E. coli, and produced LCFA esters containing methyl branches at both acid and alcohol moieties at 35 mg/L with a yield of 1.9 mg/g glycerol.
Compared to straight and terminally branched LCFAs, internally branched LCFAs are relatively rare in nature. Thermophilic bacterium Rubrobacter xylanophilus produces 12-methylhexadecanoic acid and 14-methyloctadecanoic acid as the major fatty acid species in its lipids . 13-Methylhexadecanoic acid was identified in Leptogorgia piccolo , and 9- and 12-methyltetradecanoic acids were found in cyanobacterium Scytonema sp. . The best characterized internally branched LCFA is tuberculostearic acid (TSBA, 10-methylstearic acid) that is produced by Mycobacterium tuberculosis and related species . TSBA is used as a clinical marker for the diagnosis of tuberculous and may play an important role in the persistent phase of infection . Similarly, cyclopropane fatty acids (CFAs) that contain a cyclopropane ring represent another class of internally methyl-branched LCFAs. CFAs are major lipid components of many bacteria, such as E. coli, S. typhimurium, and M. tuberculosis. They are also found in the seed oils of some higher plants including Malvales, Fabales, and Sapindales . The position of the methyl group has strong effects to physical properties of branched LCFAs and their derived biofuels, with the greatest effect occurring at the mid of the acyl chain . For example, internally branched LCFAs have even lower freezing points compared with terminally branched LCFAs . Therefore, internally branched LCFA-derived biofuels are more promising than those derived from terminally branched LCFAs. Until now, there has not been much engineering work toward the overproduction of internally branched LCFAs. Thus, we will focus on the recent developments on the understanding of their biosynthesis.
In M. tuberculosis and related species, TSBA has been found in multiple phospholipids such as phosphatidylethanolamine (PE), phosphatidylinositol (PI), and diphosphatidylglycerol (DPG), and glycolipids such as phosphatidylinositol mannosides and lipoarabinomannans . These glycolipids are virulence determinants associated with M. tuberculosis and are likely involved in subverting the immune system . Only small amounts of TBSA can be detected in purified triglycerides (TAGs) , indicating that the TSBA pathway enzymes recognize specific phospholipid substrates (Fig. 4a).
The mechanism for TSBA synthesis is still not fully understood. It was hypothesized that the biosynthesis of TSBA involves two reaction steps (Fig. 4b). The first step is the methylenation of the oleic acid (18:1Δ9) moiety of phospholipids by a methyltransferase using S-adenosyl-l-methionine (SAM) as the methyl donor. The second step is the reduction of the intermediates, which are believed to be 10-methylene-octadecanoyl phospholipids, by a reductase using NADPH as the cofactor . Meena et al. demonstrated that a methyltransferase encoded by umaA from M. tuberculosis H37Rv is capable of converting the oleoyl-phosphatidylcholine (PC) to TSBA-PC in vitro. Meena et al. also showed that another methyltransferase encoded by ufaA1 can also catalyze the formation of TSBA. Purified recombinant UfaA1 protein can convert oleoyl-phosphatidylcholine and oleoyl-PE to TSBA-PC and TSBA-PE in the presence of SAM and NADPH. However, neither umaA nor ufaA1 has any functional domain associated with redox reactions. Machida et al. later identified a gene cluster from Mycobacterium chlorophenolicum that is responsible for TSBA production. In this cluster, the bfaB gene encodes a SAM-dependent methyltransferase, and the bfaA gene encodes a FAD-dependent oxidoreductase. Heterologous expression of these two genes in E. coli produced TSBA from oleic acid, confirming their functions. These two enzymes, BfaA and BfaB, were found to have surprisingly high regioselectivity, only converting 18:1Δ9, but not 16:1Δ9 nor 18:1Δ11 to branched fatty acids when tested in E. coli. Furthermore, it is not clear which phospholipids can be the substrates of the TSBA enzymes. Additionally, because unsaturated fatty acids (UFAs) are usually located at the sn-2 position of phospholipids in E. coli, TSBAs produced in E. coli are likely located at sn-2 position . Meanwhile, in mycobacteria, TSBA is usually found at the sn-1 position of phospholipids. These results suggest that BfaA and BfaB might be able to convert UFAs at both sn-1 and sn-2 positions of phospholipids [77, 78]. Further studies are needed to illuminate their substrate specificities.
Similar to other branched LCFAs, CFAs are also believed to modulate the fluidity and stability of cell membranes. CFAs are important to improve cell survival when microbes are subjected to environmental stresses such as high osmotic pressure , high (low) temperature [79, 80], low pH , and organic solvent conditions . Specifically, an increased level of CFAs was observed in E. coli after exposure to pH 4 for 16 h . Deletion of CFA biosynthetic genes in P. putida results in decreased cell tolerance to organic solvents . Additionally, CFAs also play an important role in bacterial virulence and persistence. For example, deletion of the M. tuberculosis pcaA gene, which encodes a CFA synthase and acts on α-mycolates, inhibits M. tuberculosis from killing infected mice .
Biosynthesis of CFAs is catalyzed by cyclopropane fatty acid synthase (Cfa), which transfers a methylene group from SAM to the double bond of UFAs, creating a cyclopropane ring on the alkyl chain (Fig. 5). CFAs are typically produced from preexisting cis-UFAs of phospholipids through the Kennedy pathway (Fig. 4a). Therefore, most natural CFAs retain the cis configuration . An in vitro study of the E. coli Cfa indicates that this enzyme has activities on different types of phospholipids including PE, phosphatidylglycerol (PG), cardiolipin (CL), and PC. In addition, the E. coli Cfa was reported to prefer preferentially act the sn-2 position of phospholipids , whereas Cfa from Sterculia foetida acts on sn-1 position .
The formation of CFAs occurs at the onset of the stationary phase in the cell growth cycle and continues until all of the cis-UFAs of the membrane phospholipid bilayers are converted into CFAs. This growth phase-depended regulation of CFA synthesis is caused by a RpoS-dependent promoter, which is activated only when cells enter stationary phase. In addition, the activity of the Cfa protein is also believed to be controlled by an unidentified energy-independent protease that is transcribed by a RpoH-dependent promoter .
Although CFAs has not been currently used as biofuels, their lower melting temperature compared to straight LCFAs and improved stability against oxidation compared to unsaturated FAs have made them promising biofuel targets as recently explored . By introducing the cfa gene from E. coli into cyanobacterium Synechocystis sp. PCC 6803, CFAs were produced in engineered cells with up to 30% of total fatty acids . In addition, engineering their biosynthesis could improve the tolerance of bacterial host to harsh conditions. For example, overexpression of cfa in C. acetobutylicum ATCC 824 showed an increased butanol tolerance , while a cfa-deficient E. coli or S. typhimurium was very sensitive to acid stress. Yu et al. expressed the E. coli cfa gene in the seeds of Arabidopsis and resulted the accumulation of CFAs up to 9.1%. By coexpressing a Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT), the CFA content was further increased to 35%.
We reviewed the progress of branched-chain biofuels, including branched short- and long-chain alcohols, alkanes, and esters. As we understand more about the biochemistry and regulation of lipid biosynthesis, novel metabolic pathways have been continuously developed, leading to new generations of biofuels with structures and properties highly similar to or identical with existing petroleum-derived fuels. The reviewed studies have proved the concept of producing advanced biofuels from engineered microorganisms; however, current titers and yields are still too low for economically viable production. These challenges demand efficient metabolic engineering tools to improve pathway yields, titers, and production stability of engineered microbial strains. Fortunately, some tools are already emerging and used for biofuel production, for example, modeling-guided pathway optimization , metabolite biosensor-enabled high-throughput screening and dynamic pathway regulation , and microbial population control tools to improve ensemble production . Additionally, there is a clear trend to move these pathways and engineering strategies into industry-relevant microbial hosts. Hopefully, these current and future efforts will enable the conversion of various low-cost, abundant and environmental-friendly feedstock into advanced branched-chain fuels at high titers, yields, and productivities in industry-relevant scales.
WB wrote the introduction, terminally branched long-chain fuels and conclusion sections. SW wrote internally branched fatty acid-derived fuels section. WG wrote branched short-chain biofuels section. FZ designed, conceived, and critically revised it. All authors read and approved the final manuscript.
This work was supported by the Department of Energy (DESC0018324) and the National Science Foundation (MCB1453147).
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The Eighth and Ninth Streets Crosstown is a public transit line in Manhattan, New York City, United States, running mostly along Eighth Street, Ninth Street, Tenth Street, and Christopher Street through the West Village, Greenwich Village, and East Village. Originally a streetcar line, it is now the M8 bus route, operated by the New York City Transit Authority.
The M8 begins at the intersection of Christopher and West Streets, on the west side of Manhattan. From West Street to Greenwich Avenue, the bus runs west along Christopher Street and east along West 10th Street. At Greenwich Avenue, the bus runs west along West 9th Street and east along West 8th Street. These become East 9th and East 8th Streets, respectively, east of Fifth Avenue (east of Third Avenue, East 8th Street is known as St. Mark's Place). At Avenue A, both directions cross over to East 10th Street to avoid Tompkins Square Park. The route terminates on East 10th Street, just east of Avenue D.
The Christopher and Tenth Street Railroad was chartered on April 25, 1873 and opened soon after (other sources give August 6, 1873 as the incorporation date). It traveled across the island between the Christopher Street Ferry on the Hudson River and the East Tenth Street Ferry on the East River. Tracks were built east from the Christopher Street Ferry dock to West Street, where it crossed the West Belt Line. Eastbound trains continued east on Christopher Street, while the westbound track curved north in West Street after crossing the West Belt Line and turned east on Tenth Street. The one-way pair continued to Greenwich Avenue, through which the Seventh Avenue Line ran; cars turned southeast on Greenwich Avenue and east on Eighth Street along the Seventh Avenue Line tracks. The Seventh Avenue Line turned south at Macdougal Street, while the Eighth Street Crosstown continued along Eighth Street to Cooper Square. There the westbound track split to the northeast on Astor Place/Stuyvesant Street to reach Ninth Street, and the tracks were separated in Eighth and Ninth Streets to Avenue A. Trains turned north in Avenue A for two blocks (eastbound) or one block (westbound), along Forty-Second Street and Grand Street Ferry Railroad trackage, to Tenth Street, and then turned east again for the rest of the line to the East River. The trackage in Tenth Street east of Avenue C had been built by the Houston, West Street and Pavonia Ferry Railroad.
On May 28, 1890, the Central Crosstown Railroad, which owned the 17th and 18th Streets Crosstown Line from the Christopher Street Ferry east-northeast to the East 23rd Street Ferry, leased the Christopher and Tenth Street Railroad. The growing Metropolitan Street Railway acquired a majority of stock of the Central Crosstown in May 1897, and leased the companies on April 1, 1904. Two months after the Williamsburg Bridge opened, on February 16, 1904, a second service pattern was added, taking some trains south on Avenue A and the one-way pair of Essex Street and Clinton Street (the latter via 1st Street) to reach Delancey Street and the Williamsburg Bridge, ending at a loop on the Brooklyn side. Due to the Metropolitan's bankruptcy, their lines over the bridge were replaced in 1911 by a single one, the Seventh Avenue-Brooklyn Line, which shared trackage with the Seventh Avenue Line from Central Park to Greenwich Village, turning east on the Eighth Street Crosstown Line and over the bridge to Brooklyn. That service was discontinued in 1919.
Buses were substituted for streetcars by the New York City Omnibus Corporation on March 3, 1936. That company changed its name to Fifth Avenue Coach Lines in 1956; the Manhattan and Bronx Surface Transit Operating Authority took over operations in 1962.
Because of economic troubles facing the MTA in 2008–2009, the M8 bus was proposed for elimination. However, after community protests, the proposal was withdrawn in May 2009. But in June 2010, further budget cuts took away weekend and overnight service on this line. Weekend service was reinstated on April 6, 2014, as part of the MTA's 2013-14 Service Enhancements Program.
^ Google (May 8, 2017). "M8" (Map). Google Maps. Google. Retrieved May 8, 2017.
^ Jackson, Kenneth, ed. (1995). The Encyclopedia of New York City. Yale University Press. p. 978.
^ Sarah Kramer (May 6, 2009). "M8 Bus Riders Say "Hallelujah!"". WNYC. Archived from the original on July 23, 2011. Retrieved July 18, 2009.
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A former US Air Force intelligence officer has been charged with helping Iran target ex-colleagues with cyberattacks after defecting to the country in what was dubbed a 'betrayal' of America. Monica Witt, 39, was accused of switching sides after more than a decade of US military service and identifying American intelligence officers and their personal Facebook accounts for the Iranian regime. Messages quoted in an indictment unsealed yesterday showed Witt saying that she wanted to 'put the training I received to good use instead of evil' around the time of her defection. Four Iranians said to have been involved in the cyber-attacks were also charged along with two Iran-based businesses, New Horizon Organization and Net Peygard Samavat Company. The five individuals charged are all at large, meaning the chances of a successful prosecution remain unclear. The investigation to uncover the alleged crimes was being run for years. John Demers, the US assistant attorney general, said: 'This case underscores the dangers to our intelligence professionals and the lengths our adversaries will go to identify them, expose them, target them, and, in a few rare cases, ultimately turn them against the nation they swore to protect." Image released on February 13, 2019 showing the missing person page of the FBI website for Monica Witt Credit: HO/AFP/Getty Images Witt, a US citizen, worked for the US Air Force as an intelligence specialist and special agent between 1997 and 2008. She worked with the Defence Department as a contractor until 2010. During her service she was given access to secret and top secret information relating to counterintelligence, including material that contained the true names of secret agents and sources. Early in her career she was taught the Farsi language and was deployed in a number of overseas locations, carrying out missions to counter America's enemies. Witt repeatedly promised to act in America's interests and not share classified information she accessed, according to US prosecutors ' pledges which she is accused of flagrantly breaking. The first signs of Witt's alleged defection came when she attended the Iranian New Horizon Organization's 'Hollywoodism' conference in February 2012. The gathering was sponsored by the Islamic Revolutionary Guard Corps, a branch of Iran's armed forces which was recently sanctioned by the Trump administration for its 'malign' activities. The conference was partly aimed at 'condemning American moral standards and promoting anti-US propaganda', US prosecutors said. By August 2013, just 18 months later, Witt had fled to Iran. Messages between Witt and an unnamed Iranian-American who helped arrange the trip which were published in the indictment give an insight into her thinking before the defection. 'Should i thank the sec of defense . . u were well trained,' the unnamed individual allegedly wrote to Witt in one message before her trip, appearing to reference the US defence secretary, her old boss. Witt responded: 'LOL thank the sec of defense' For me' Well, I loved the work, and I am endeavoring to put the training I received to good use instead of evil.' She added a smiling emoji and the words: 'Thanks for giving me the opportunity.' In another message Witt wrote 'If all else fails, I just may go public with a program and do like Snowden :)'. The apparent reference is Edward Snowden, the former CIA employee who leaked classified material in 2013 and then fled to Russia. Once Witt was in Iran she was given housing and computer equipment by Iranian government officials, according to US prosecutors. She is then accused of disclosing classified information about secret US projects and combing Facebook under an alias to identify former colleagues, putting together 'target packages' that would help the Iranians find, track and 'neutralize' the threat posed. The four Iranians charged in the indictment then began a 'malicious' campaign of targeting Witt's former colleagues, according to US prosecutors. The allegations included using fictitious or imposter Facebook accounts to send messages with links that would compromise their computers once clicked. The Iranian nationals charged with computer intrusion and aggravated identity theft are Mojtaba Masoumpour, Behzad Mesri, Hossein Parvar and Mohamad Paryar. Terry Phillips, a US special agent with the Air Force, said: 'The alleged actions of Monica Witt in assisting a hostile nation are a betrayal of our nation's security, our military, and the American people. 'While violations like this are extremely rare, her actions as alleged are an affront to all who have served our great nation.' It is not known how those charged will plead if the case came to court. The five individuals charged had not commented publicly in the hours immediately after the indictment was unsealed.
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0.933893 |
Changing regirock's name back to English X/Y?
I have received a regirock via the GTS however it has a Japanese name and i'm not really too keen on having that, is there any way at all that I can change the name?
i'm fairly certain that regirock is hacked.
How can you say that when all we know is that the Regirock has a Japanese name?
Because regirock isn't available in normal gameplay andpoketransfer isn't available yet, unless the japanese person was one of the few people who was able to get pokemon bank and poketransfer.
Since you cannot breed another Regirock, no.
However, if you can breed another Pokemon, the offspring will have an English name.
If you have a Pokemon you can breed and breed it with a Pokemon of another country (like Korean Sylveon with English Glaceon), the offspring has a x6 probability of being shiny!
If you absolutely need a Regirock with an English name, catch it in Ruby/Sapphire/Emerald, Platinum, or Black/White 2 and migrate it to X & Y.
If you caught it in R/S/E, transfer it via Pal Park to a Gen4 game, then transfer it via Poke Transfer to B/W or B2/W2, and then migrate it to X & Y via Poke Bank.
If you caught it in Platinum, transfer it to B/W or B2/W2 via Poke Transfer, then migrate it to X & Y via Poke Bank.
If you caught it in B2/W2, migrate it to X & Y via Poke Bank.
Source: Korean Sylveon on my team and English Eevee in PC Box, and experience.
However, don't get down on having a Japanese Regirock, it's more authentic to receive a Pokemon from the country it's idea was conceived in!
How do you even get a non English named pokémon?
The only way to get a Pokemon to change its language is by evolving it or by hacking. Since Regirock can't evolve, you can only hack to change its name.
If you really just want a Regirock with an English name, catch one in B2W2 and transfer it via Pokebank or trade for another one.
If Pokemon X and Y are being releast at the same time worldwide then are the Pokemon names already in english?
What are all of the names that you can't name your Pokemon in X/Y/OR/AS?
What is the name of the Route Transition / Rest Stop music in PKM X+Y?
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0.999988 |
A: I went to a restaurant yesterday.
B: That sounds nice. How was the restaurant?
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0.993817 |
Did big projects used to get finished on time and on budget?
Big projects (software, engineering, architecture etc.) are plagued by cost and time overruns, or so it is widely thought.
But the puzzle was that such underestimation did not seem to exist in the past century or so, though we were dealing with the very same humans, endowed with the same biases. Many large-scale projects a century and a half ago were completed on time; many of the tall buildings and monuments we see today are not just more elegant than modernistic structures but were completed within, and often ahead of, schedule. These include not just the Empire State Building (still standing in New York), but the London Crystal Palace, erected for the Great Exhibition of 1851, the hallmark of the Victorian reign, based on the inventive ideas of a gardener.
Is this just because we remember the successful ones are is his generalization right? Did we used to do a better job of delivering big projects on time and on budget?
In fact almost all projects will fail to meet some of the criteria they originally started with. Sometimes they don't make it on time or others fall short on budget. That is the idea most engineers have, and many times they do plan knowing that at some point they won't be able to deliver what was originally intended. Now the reason that they do fail is due to unrealistic expectations from the executive management, or in general people who make the calls without actually having any expertise on the subject, unrealistic planing (sometimes due to pressure), human errors (accidents etc), and a a rather huge reason according to myself is the lack of proper communication (the requirements are not stated clearly so we end up with many time consuming errors). In fact only a third of all projects were successfully completed on time and on budget over the past year according to CHAOS. Please read this for a better analysis.
Also have a look at some notable project failures here.
Continuing on you question on if things are getting worst or not we can safely assume that in fact project success rates are rising rather than falling, according to surveys at least (Have a look here). Personally i do believe this is the case if we exclude IT project. All the factors stated before do apply here as well, and there are just so many project with unrealistic expectations that are deemed to fail in some way (Have a look at this article too).
Summarizing i have to say that project failure rates were dropping over the period from 1994 until 2011, with a high rise last year. Have a look at the tables below for more info.
Standish Findings By Year. Updated for 2009 report.
Not the answer you're looking for? Browse other questions tagged history engineering .
Did Robin Hood exist and get buried here?
Was torture and execution commonly used by the Spanish Inqusition?
Did Al-Aqsa Mosque exist when it was used as a praying direction?
Did the Britons stop growing crops in the time between 3300BC & 1500 BC?
Did Babylonians in BCE used geometrical methods in mathematical astronomy to calculate planet positions and its motions?
Did lightning strike Major Summerford three times and his gravestone too?
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0.999999 |
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0.999775 |
The first is the difficulty of measuring anything underneath kilometers of ice. Typically geoscientists gain a better understanding of the Earth's inner workings by sending sound waves into the ground and measuring the time and angle at which they return to the surface. Using complex mathematical algorithms, geophysicists are able to reconstruct a three-dimensional picture of the subsurface. However, this was difficult to do when any acoustic signal has to travel through kilometers of chaotic ice, causing significant noise in the subsurface "picture" beneath Antarctica.
The second is the counterintuitive nature of having a massive heat source underneath an area that is covered with kilometers of ice. With an average ice sheet thickness of 2.16 km and a maximum thickness of around 4.7 km, it's hard to believe there is a massive heat source similar to the one in Yellowstone sitting beneath the ice. How has the heat source not prevented ice build up?
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0.998513 |
Why did japan open its ports to european trade after centuries of isolationism?
Position:Home>History> Why did japan open its ports to european trade after centuries of isolationism?
Question: Why did japan open its ports to european trade after centuries of isolationism!? 10 POINTS!!!?
A) Mt!. Fuji erupted and Japan needed assistance!.
B) A flood of foreigners entered the country, demanding more trade!.
C) A chinese invasion forced Japan to end its isolationism!.
Did you get these multiple choice questions from a Japanese History textbook!? The choices given are so absurd, they almost appear to be written by the Japanese 70 years ago!
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0.999997 |
What does “up she rises” mean in the sea shanty “Drunken Sailor”?
It's early in the morning, so perhaps the sailor in question is rousing from his drunken stupor. But sailors were traditionally all men, so why "up she rises"? Is the sailor being mocked, or does it refer to something else entirely?
An additional gold doubloon will be awarded for an explanation of the odd pronunciation of early (earl-aye /ˈɜːlaɪ/).
Capstan shanties: Sung while raising anchor. Also known as "stamp and go chanties" because sailors would stomp the deck while turning the capstan.
Halyard shanties (Long Drag Shanty): Sung to the raising and lowering of sails. The crew would rest during the verse and haul during the chorus.
Windlass and pumping shanties: the windlass is also used to raise the anchor. Sailors would pump handles up and down, making the barrel of the windlass rotate to bring the anchor chain up. There were several different types of pumps, which accounts for the variation in the timing of pumping shanties.
Ceremonial shanties and forecastle songs: songs were those sung by sailors on their time off (of which they didn't have a great deal). Ceremonial shanties were for times of celebration, such as when the sailor paid off his debt to the ship or when they crossed the equator.
The capstan shanty was a moderate tune sung to raising the anchor. In order to raise the anchor bars were inserted into the capstan and sailors would walk around it, turning the capstan to raise the anchor. Sailors would stamp on the deck on the words "Way Hay and Up She Rises."
This takes place early in the morning, so she could be the rising sun. But sea shanties are work songs so it is more likely to refer to raising the very heavy main sail and the gaff (cross beam) that would require the whole crew to heave it up.
Stamp-'n'-Go Shanties: were used only on ships with large crews. Many hands would take hold of a line with their backs to the fall (where the line reaches the deck from aloft) and march away along the deck singing and stamping out the rhythm. Alternatively, with a larger number of men, they would create a loop—marching along with the line, letting go at the 'end' of the loop and marching back to the 'top' of the loop to take hold again for another trip. These songs tend to have longer choruses similar to capstan shanties. Examples: "Drunken Sailor", "Roll the Old Chariot". Stan Hugill, in his Shanties from the Seven Seas writes: "["Drunken Sailor"] is a typical example of the stamp-'n'-go song or walkaway or runaway shanty, and was the only type of work-song allowed in the King's Navee (sic). It was popular in ships with big crews when at halyards; the crowd would seize the fall and stamp the sail up. Sometimes when hauling a heavy boat up the falls would be 'married' and both hauled on at the same time as the hands stamped away singing this rousing tune."
As to the earl-aye pronunciation, Colin Fine commented this is sometimes used by traditional folk-singers today. I expect this is done to give it rhythm.
To "weigh anchor" means to lift it up from the seabed and return it to its 'stowed' configuration on the ship. So when you "weigh-heigh", up the anchor (which, being a part of the ship, is naturally also a "she") rises from the sea.
I always had the impression that "she" refers to the boat rising and falling with the waves on the sea the boat is sailing.
I would guess the earl-aye pronunciation is (at least in part) an elision, particularly since "early" is followed by "in". This may have been done for the sake of "rhythm" (although I believe the more proper term here would be "meter").
The pronunciation may also have been affected by the ethnicity of the naval crews (it was fairly common for, say, young Irish males to be kidn-, ahem, conscripted into naval service).
But that's just a (semi-)educated guess.
I think it's the ship itself. They had female names.
“Up she rises” is a whaling term. The lookouts would shout “Up she (or there she) rises” when the whale is about to break the surface of the water. “There she steams” or “there she blows” meant that the whale was exhaling and a signal for the crew on deck to look for the water and vapor from the breathing.
I'm amazed that nobody has noted the transparent crudity of this shanty. The "drunken sailor" refers to a member of the crew suffereing erectile disfunction as a result of over indulgence and shanty suggests methods of solving it - hence "Hooray and up she rises"
Not the answer you're looking for? Browse other questions tagged pirate-english or ask your own question.
What does a phrase “Plunder for all!” mean?
What are the many meanings of the suffix -ship and can it reasonably be applied to the end of most all words?
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0.999999 |
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0.982185 |
What could be a simpler networking concept than TCP's RST packet? It just crudely closes down a connection, nothing subtle about it. Due to some odd RST behavior we saw at work, I went digging in RFCs to check what's the technically correct behavior and in different TCP implementations to see what's actually done in practice.
RCV.NXT + RCV.WND - The sequence number of the last byte of data the receiver is willing to accept at the moment.
SND.UNA - The first sequence number that the sender has not yet seen the receiver acknowledge.
SND.NXT - The sequence number of the next byte of payload data the sender would transmit.
An RST is accepted if the sequence number is in the receiver's window (i.e. RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND). The effect of the RST is to immediately close the connection. This is slightly different from a FIN, which just says that the other endpoint will no longer be transmitting any new data but can still receive some.
There are two types of event that cause a RST to be emitted. A) the connection is explicitly aborted by the endpoint, e.g. the process holding the socket being killed (just closing the socket normally is not grounds for RST, even if there is still unreceived data). B) the TCP stack receiving certain kinds of invalid packets, e.g. a non-RST packet for a connection that doesn't exist or has already been closed.
The RST packet that should be generated is slightly different for these two cases. For case A the sequence number for the RST packet should be SND.NXT of the connection. For case B the sequence number should be set to the sequence number ACKed by the received packet. In the latter case the ACK bit will not be set in the RST. (Where the distiction matters, I'll call the first one RST-ABORT, the second a RST-REPLY).
The RCV.NXT state variable is doing double duty in the original RFC 793. It's defined as "next sequence number expected on an incoming connection", but it's also implied that it's the most recent acknowledgement number sent out. This was true early on, but not after the introduction of delayed ACKs (RFC 1122). Which of these two interpretations should be used for checking whether the RST is in window?
Linux goes with the latter one, and splits the two roles out. RCV.NXT is strictly defined as the next expected sequence number, and RCV.WUP is the highest sequence number for which an ACK has actually been sent. RST handling is done using RCV.WUP, and in fact the following comment implies that RSTs are the main reason for this mechanism.
* delayed ACK, so that hisSND.UNA<=ourRCV.WUP.
The use of RCV.NXT instead of RCV.WUP for the second subexpression is a clever ruse; due to the way tcp_receive_window() is defined, the final result is relative to RCV.WUP instead of RCV.NXT. But it is a slightly mysterious piece of code. Why is SND.UNA relevant? It should be SND.NXT that matters.
But that's extremely contrived, and would be easily broken by delays (all that needs to happen is for that delayed ACK to actually get emitted before the second RST is received, and it would get rejected).
* we should test against last_ack_sent instead of rcv_nxt.
The bit I bolded does make it appear that the motivation for the change was specifically RST-REPLYs, not RST-ABORTs. If you're looking for an exact match with some ACK you've sent, it'd be insane to try to match an ACK that had never been sent. But if the other kind of RST had been considered, it would have been obvious that in the presence of delayed ACKs a valid RST could have a sequence number higher than last_ack_sent.
This rule of exact match was indeed later changed in various ways; first reverted to accepting all RSTs in window (so just moving the window), then re-enabled while socket is in ESTABLISHED state but being less strict in other states, then loosened to accepting either RCV.NXT or last_ack_sent, or accepting either of those ± 1, etc.
If you're already tracking last_ack_sent / RCV.WUP, doing the window checks on that instead of RCV.NXT seems sensible. But it does feel like an optional thing, rather than one of those pieces of necessary TCP behavior that were only standardized in folklore.
RST in-window but not RCV.NXT, send an ACK (if the RST was genuine, the other endpoint will send a new one but this time with the correct sequence number).
This means that even for the above contrived case using a RST.WUP as the start of the window doesn't make a substantial difference. One extra round-trip is required no matter what; whether the ACK is the delayed ACK or the challenge ACK to a semi-bogus RST is immaterial.
That's pretty fertile ground for different implementations. One standard, one ambiguity that appears to have never been officially clarified, and one proposed standard. I could go into more detail on the archaeology or on how to perform the experiments for if the source code isn't available. But that'd get tedious, so here's a summary of my best understanding of how various operating systems work for RSTs received in the ESTABLISHED state (the picture assumes a last ACK sent of 12, last sequence number received of 17, and a window of 10).
Yes, seven operating systems and no two even agree on what an acceptable RST looks like! And there's still some scope for other reasonable but different implementations beyond those. RFC 5961 handling but with the window based on RCV.NXT, and RFC 5961 handling that accepts both RCV.WUP and RCV.NXT as the sequence number would be obvious examples. (To be fair, some of these differences will collapse away if no ACKs are currently being delayed when the RST is received).
The one data point in that table that seems particularly strange is RCV.NXT + 1 in OpenBSD. If you're going to widen the window of acceptable sequence numbers by 1, I would have thought that adjusting it downwards rather than up would be the obvious choice. The commit message is pretty spartan, just blaming Windows.
You could get into some further complications with the window handling for RSTs that include data (sigh, the awesome idea in RFC 1122 to embed the reason for the RST as ASCII payload), but AFAIK those don't exist in the wild so maybe this is enough for now.
The above was just considering RST handling from the point of view of the endpoints, where the main question is whether to react to an RST, not how you react to it. Things get different yet again for middlebox. The middlebox might not actually have the same understanding of the state variables as either of the endpoints. If the reaction of the middlebox to the RST is somehow destructive, the middlebox has to be careful. As a trivial example, imagine a firewall that blocks all packets for unknown connections. It would be quite bad for that firewall to react to a RST packet that the actual endpoint rejects.
What if the middlebox is not just TCP aware, but an active participant in the connection? At work we do a fully transparent non-terminating TCP optimizer for mobile networks (see previous post for more technical details if that's your kind of thing). Despite not terminating the connections, we still ACK data and thus take responsibility for delivering it. How should a device like that react to a RST if we still have undelivered but ACKed data? It actually depends on which directions we've seen a valid RST in. To a first approximation we should stop sending new data to the direction that we've gotten RSTs from, but not close the connection or forward the RST packet until all data that we've acknowledged has been delivered to the destination of the RST. (With the edge case of valid RSTs in both directions forcing connection closure even with undelivered data).
So there are a bunch of different ways to process a RST, but surely sending RSTs is trivial? The rules on that are simple, unambiguous, and unlike for processing an incoming RST there should be no motivation to deviate from the rules. There are good reasons to be stricter about accepting RSTs, there should be no reason to send RSTs that will get rejected.
First, what does SND.NXT really mean? RFC 793 only describes it as the "next sequence number to be sent". On the face of it this could mean two things; either it's the highest sequence number that has never been sent. Or it could be the next sequence number to be transmitted including retransmissions. The latter interpretation seems morally bankrupt. The RFC describes a mechanism by which SND.NXT increases, but not one by which it decreases. The glossary also explicitly mentions retransmissions as falling between SND.UNA and SND.NXT, which implies SND.NXT should not decrease.
In this example when the client sends the RST, SND.UNA should be 973095334 and SND.NXT should be 973096882 - highest sequence number sent, and in fact selectively acked. The RST is not generated with either of those, but the in-between sequence number of 973096734.
The first RST has the same sequence number as the FIN. That's the correct behavior, since that RST was sent in reply to a packet that was already in flight to the client by the time the server received the packet. Apperently OS X had the RST get triggered by an incoming packet before it got around to sending an RST with a useful sequence number. So there's an extra round trip's delay, and possibly an extra round trip's worth of packets. But that's not a huge deal.
We get a single RST, which for an active connection almost guaranteed to have a sequence number that will be rejected. Without at least one valid RST, the server has to keep the connection open, and data gets wastefully retransmitted over and over. This lasts until the server times out the connection, which might take anything from ten seconds to two minutes.
And just to be clear, the phone was still connected and functional for the full duration of that trace. There were other active connections to it, and those continued happily along. It's just the closed sockets that become total black holes.
Note that the RCV.WUP trickery discussed in the earlier section alone would not be sufficient to handle this kind of a situations. In addition you need to either delay ACKs to FINs (OS X), be more forgiving about RSTs after receiving a FIN (OSX, FreeBSD 10.2), or have a small amount of slack in the sequence number check (±1 in FreeBSD 10.2; OpenBSD has slack but in the wrong direction).
To see how much of a difference these different variations have, I ran some simulations against a trace from a varied real world traffic mix and looked at what percentage of first RSTs received by the server would have been accepted, vs been dropped or caused a challenge ACK. (I grouped challenge ACKs together with dropping packets, since the point here is to see which policy is the most efficient at actually closing the connection as soon as possible. It's not to see which ones manage to do it eventually. Either they'll all manage to do it later since some packets will be sent eventually, or none of them will do it since the other device isn't properly sending followup RSTs. Also, an after the fact simulation can't possibly tell anything about the efficiency of the challenge ACKs).
The data was filtered such that we only looked at connections matching the following criteria. This was about 35k connections after the filtering, so not a huge data set. This was almost exactly 1/3 RST-ABORTs and 2/3 RST-REPLYs.
Also not that this is only comparing the different policies for RST acceptance, not for example the effects of different delayed ACK behavior in different TCP implementations.
Illumos is the only implementation here using the standard check against the massive full window (tens or hundreds of kilobytes, vs. 1-6 bytes for everything else. So it's not much of a surprise that it's more effective than the others at closing the connection on just about every RST-ABORT it receives. The tradeoff is that it's a lot more susceptible to RST spoofing attacks.
FreeBSD 10.2 accepts a superset of what OpenBSD does.
OpenBSD accepts superset of what Linux and Windows do.
When there is no FIN, checking RCV.NXT is more predictive of the sequence number of a RST-ABORT than RCV.WUP would be, so anything not checking RCV.NXT loses out.
OS X relaxes the checks after receiving FIN, FreeBSD CURRENT no longer does.
For RST-REPLY, practically everyone gets the case of no FIN right. But if there's a FIN (like in the iOS example above), FreeBSD 10.2 is vastly more effective than anything else thanks to accepting RCV.NXT - 1. There's not much of a tradeoff. It's a good idea, and I'm a bit surprised that not only did it never spread outside of FreeBSD, but has now been removed from there too.
The other results are boring, with just the RCV.WUP vs. RCV.NXT difference (with the opposite results compared to RST-ABORTs).
Almost every time I talk about TCP optimization to the general development public, the reaction is something along the lines of "ah, you're one of the guys who breaks the standard?". That's technically true but useless; nobody actually implements all the standards exactly as written. Hopefully this dive into just one relatively simple aspect shows a) everyone doesn't interpret the standards the same way, b) there are reasons to intentionally deviate from the standards, and c) everybody does it. You just can't be abusive when deviating from the standards.
Oh, and I'd already implemented accepting RSTs with sequence number RCV.NXT - 1 before looking at these details (resetting the connections promptly is kind of important for us due to reasons that I can't go into here). But this investigation did make me feel a lot better about that change.
Wow, your posts are so good! I hope to know the rules well enough to someday know exactly when and how to bend them.
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0.998802 |
I'm modifying an old power amp, which has a very sophisticated speaker protection circuitry To make things easy with my modifications, I would like to place a relay at the amplifier output.
Does anyone have experience with SSRs as speaker on/off switch?
Or do you see any problems using these (apart from heat dissipation)?
The SSR such as you mention use triacs and are unsuitable for use as a speaker relay because they would generate massive non linear distortion around the zero crossing point.
SSR's made using two power FET's and a floating photovoltaic coupler are the way to go and many have used these successfully. I would never go back to mechanical relays now.
Do you think, I can use the 4N35 right away or would you recommend to replace them with the PVI1050A optos?
If you are unsure of anything then just ask.
I would have thought they might introduce some cross over distortion as the phase changes as one transistor turns off and the other on.
You mean, the red trace in the second picture corresponds to a circuit like posted here ?
Thank you, LKA, for sharing this information!
But how to interpret these measurements? With my naive perspective, I'd say: There is no difference between parallel and serial optos.
As I already have a fault detection circuit in place which provides an open collector driver, I will only need the optos, the two MOSFETs, and a serial resistor to adjust the LED current - less is more And for the optos, I will probably go for the serial configuration to be on the very safe side with the voltage.
Or did I miss something with the interpretation of the measurements?
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0.959467 |
Here is a step by step tutorial showing you how to make a beautiful chocolate cake.
25 grams or 1 oz Cocoa powder.
I use a 6 inch tin that is 3 inches deep, however this could be used to make a 7 or 8 inch cake with a smaller depth. If you use an wider and thinner tin reduce the baking time by around 15 minutes, as thinner cakes take less time to bake.
1. Weigh out your margarine or butter and sugar and place in a mixing bowl.
2. Mix them together using an electric whisk, then add your eggs in to the mix one at a time, whisking after each one.
3. If using a ‘light’ margarine then your mixture will look like this, if you have used butter it will be thicker in texture.
4. Now weigh out your flour and cocoa powder and sieve into the mixture.
5. I would now fold the wet and dry ingredients together using a spatula just to help combine them a little. This is so that when you whisk the ingredients they do not fire up onto you and your work surface.
6. Whisk the ingredients together until fully combined, make sure you scrape down the sides of the bowl with a spatula and mix in. Now taste test the mixture by scooping a little out with a spoon, if the mixture tastes floury or bitty then whisk a little longer until all the ingredients have combined, if you re check the mix again then ensure to use a new clean spoon, if it tastes smooth it can now be transferred to the tin.
7. You will now need some baking parchment and your tin. Take your tin and place it on a piece of baking parchment.
8. Draw around the base of the tin with a pen or pencil and then cut out the circle ensuring you cut off all the pencil marks on the baking sheet. If you do not then the pencil marks can transfer onto the cake.
9. Now grease your tin using either butter or cake release. I use a Bake Easy spray.
Spray the Bake Easy on the base and up all the sides of the tin, I spray the tin over my sink so that the spray does not go all over the kitchen sides.
10. Now place the pre cut baking parchment into the base of your tin pushing it around the edges and ensuring all the base is covered.
11. If you wish you may add a little more spray to the baking parchment.
12. Now slowly pour your chocolate cake mixture into the tin.
13. Fill the tin about ¾ full.
14. Place on the middle shelf of the oven and bake for approx 50-55 mins. You may wish to check your cake at around 45 mins depending on your oven. Check the cake by inserting a skewer into it. If the skewer comes out clean the cake is baked if there is still a gooey mixture attached to it then the cake needs to be baked for a little longer. Repeat the skewer process in five minute intervals until fully baked. Once baked remove from the oven and place the tin on a wire rack. Leave the cake in the tin for approx 10 minutes before removing so that it can shrink away from the edges and will remove from the cake tin easier.
15. Carefully tip the cake onto the wire rack, remove the baking parchment by slowly peeling it away from the cake, now leave to cool fully, you may wish to place the cake back up right after about 30 mins.
16. This cake can now be level, filled and covered with icing or simply filled with chocolate buttercream.
This cake was also used as the top tier of my Frozen Cake.
PrevPrevWhat is a double ended ball tool?
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0.959635 |
Canada Goose sale Assume for the moment that this data Chief Justice Roberts is looking for is available and it supports a continuation of Section 4, updated to accommodate the new information. Given that, what is a possible, or maybe even probable outcome? In my considered opinion, the outcome will not be good for at least three years. For the next two years, until Dec 2014, Congress will probably do nothing other than argue with itself, if they do anything Canada Goose sale.
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0.928304 |
I am a scientific researcher, and my job is to study DNA. DNA is pretty cool because it contains the instructions for growth, development, functioning, and reproduction of all known living organisms, including humans! I am studying DNA to figure out how it ultimately influences human traits and diseases, such as cardiovascular disease.
I am motivated by the big question, “How does our genetic information contribute to our health?”, so every day, I try to make one small step towards answering that question. In my current position, I am a “dry lab” scientist, which means that I often analyze data that other people have generated in order to answer this question. This means that I spend a lot of time on the computer, doing things like writing code to compare genetic information between multiple individuals or even multiple species. I write and also read papers from other people about how our genetic information influences human health and disease. In order to complete my PhD, I need to complete 3 major projects (that each take 1-2 years).
A stereotype of scientists is that we work alone, but that isn’t true at all! We are asking (and trying to answer) really big, complications questions, which means that we have to work together. Usually, this means working with people with different skill sets than us, or more experience working on a particular topic. For each of my projects, I work closely with usually 3-5 other researchers, plus my boss, who oversees the projects. It is extremely important that we communicate with our teammates fairly often about the project. Additionally, I really like everyone that I am working with, so we will also talk about stuff other than science! We eat lunch together everyday, which helps build a good sense of community.
grades in my high school STEM classes, and have a chronic illness. In fact, during my first two years of college, I dealt with a severe, undiagnosed disease and had to take a long leave of absence in between my sophomore and junior years of college. This time off tested whether I wanted to continue to pursue science or do to something else. Ultimately, my love of discovering new things pulled me back to undergraduate research and also to graduate school.
What advice would you give a high school student looking to go into your field?
If your school or district has a high school science fair, consider getting involved, particularly if there are topics or questions that you want to dive into deeply. I’ve seen some amazing projects about all sorts of topics, including the resiliency of swimsuit fabrics (researched by a student who was a swimmer), the physiological impact of video games, and the optimal design of pet products.
Even if your school doesn’t have a high school science fair, you can still build up skills that are useful for research. For example, one of the most in-demand skills right now, even for biological research, is coding skills. There are lots of online tutorials and classes for you to teach yourself a coding language. One way to demonstrate the coding skills that you have learned is to put your scripts or projects up on github.com.
During college, you can get involved with research in a laboratory (it is possible to do this during high school like I did, but more difficult). To do so, I recommend looking at the research pages of different professors, including the professors that you are taking classes with. From there, you can narrow down which research programs interest you. For example, you might be interested in professors that do research on cancer. You can also look at their recent publications, either on their lab websites or through sites like pubmed.gov. After you have selected a handful of professors, I would recommend emailing the professor with information about why you are interested in doing research in their lab and your previous research. Be sure to attach a resume. Hopefully they will email you back asking for an interview!
Do you have any "asks" for the reader? Things they should check out or think about?
Much of the research currently being done in university biology or biomedical departments has important implications for human development, evolution, and health but is too preliminary to be funded by pharmaceutical or healthcare companies. Instead, these companies will build on early findings from universities to make their products. Consequently, a lot of university research (and researchers like me) is funded by tax revenue.
If you think the scientific research that my colleagues and I do is important, please call your Senators and House of Representatives annually and urge them to increase the budget for scientific research and development. This can include increasing the budget for the National Science Foundation (NSF) and National Institutes of Health (NIH).
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0.999913 |
A nice little bit of 'Magpieing' to start you off on what is a wonderfully descriptive setting! - Well done Anna.
Anna I love the complex sentence you had - Beneath the cystal chandelier, rows of wooden, polished tables stood with shadowy black chairs tucked underneath.
I like the way you ended the story in elipses.Keep up the good work!
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0.999999 |
May I be the first to wish your granddaughter an early Happy Birthday! I would imagine getting to spend her special day at Walt Disney World and having breakfast with princesses sounds like a perfect celebration.
While I don't think cake with breakfast is a typical experience for most people, having it once a year to celebrate a birthday is something that I think would bring joy to many people. To help you know if it would be worthwhile for your family, I'd first take a look at the breakfast menu at Akershus Royal Banquet Hall. If it looks like your family will have some room leftover after breakfast, a birthday cake could be a nice way to start your granddaughter's birthday. To order a specialized cake, you can call (407) 827-2253. It may also be helpful for you to talk with a cake specialist about different options and costs to make a more educated decision.
If you prefer not to order one, but change your mind once you arrive at the restaurant, there are generic ones available without previous notice. Just let your server know you'd like to have one for your granddaughter's birthday. Also, throughout the parks, there are lots of other treats and cupcakes that you could use to celebrate her birthday later in the day, too.
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0.644359 |
Rabbi Yeruchem Halevi Levovitz (Hebrew: ירוחם ליבוביץ; ca. 1873-1936), also known by his hundreds of students simply as The Mashgiach, was a famous mashgiach ruchani and baal mussar (Jewish Ethics) at the Mir yeshiva in Belarus.
He was born in 1873 (5633 in the Jewish calendar) in Lyuban, Minsk Voblast, Belarus (near Slutsk) to Avraham and Chasya Levovitz. He received his education in the yeshivas of Slobodka and Kelm.
He was a disciple of Rabbi Nosson Tzvi Finkel, and Rabbi Simcha Zissel Ziv of Kelm.
He was the spiritual leader of the Mir Yeshiva in Belarus until his death in 1936. His disciples were said to have followed his every word, never doing anything that they "felt" he would not want them to do. Most of the leaders of the yeshivas of inter-war Poland were Rabbi Yeruchom's disciples. They would come on occasion to visit him and seek his advice.
After World War II, much of orthodox Jewry in Europe was wiped out, along with their many yeshivas (Jewish schools of higher learning). One of the only yeshivas to survive as a whole body was the Mir Yeshiva, which managed to escape miraculously to Shanghai, China, and then on to America.
Some of his better known disciples include Rabbi Shlomo Wolbe, Rabbi Chaim Shmuelevitz, Rabbi Aryeh Leib Malin, Rabbi Dovid Povarsky, Rabbi Abba Berman, Rabbi Zelik Epstein and Rabbi Shimon Schwab.
His many discourses and lectures are preserved for posterity in the following sefarim: "Daas Torah," "Daas Chochma U'Mussar," "Shvivai Daas," and "Sifsai Daas on Pirkei Avos" which are a staple of many yeshiva libraries today, as well as many Orthodox Jewish households.
He died on the 18th of Sivan in the year 1936 at the age of sixty-three. He is buried in the town of Mir, Belarus. His grave site (recently rebuilt by his family) is a common destination for the many Jewish tourists who visit the decimated cities of pre-war eastern Europe.
Most of his family escaped the Nazis and made it to America where they were pioneers of the rebuilding of Orthodox Jewry in the United States. His son, Rabbi Simcha Zissel Halevi Levovitz, was the founder of a yeshiva in Boro Park, Brooklyn, and was responsible for publishing the writings of his father, as well as publishing the writings of Rabbi Simcha Zissel Ziv. His son in law Rabbi Yisroel Chaim Kaplan, former rosh yeshiva in Brisk, Lithuania, came to America and served as rosh yeshiva in Beth Medrash Elyon in Monsey, NY. Reb Yeruchom Levovitz's grandson then went on to open the famous Beth Hatalmud yeshiva. Reb Leib Maalin served as the rosh yeshiva until his passing, when the leadership of the yeshiva was passed to Rabbi Chaim Visokier. After Rabbi Visokier's passing, Reb Naftali Kaplan became the rosh yeshiva along with Rabbis Sholom Menashe Gotlieb, Binyomin Zeilberger and Yisroel Perkowsky.
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0.932552 |
How do you prevent eye strain while gaming?
If only Sarif Industries were real.
There are! But let's get the disclaimer out of the way: if you're having serious headaches, consult a doctor. I am not a doctor, but I do know someone who knows an ophthalmologist, Dr. Michael Hawkeswood, and I consulted with him while writing this. Dr. Hawkeswood is more of a doctor than I'll ever be, because I am not at all a doctor. I am zero percent a doctor.
That settled, the common advice for avoiding eye strain (which Dr. Hawkeswood confirms) is to look away from your display now and then and focus on a distant object. You've got to stretch out those eye-focusing ciliary muscles! (Note: 'stretch out' is probably not the term a doctor would use.) If you're playing a multiplayer game, the easy thing to do is to look away after every match. Study the most distant object in the room, or silently peer out your window, with the bonus effect of creeping out anyone outside.
And while you're stretching your eyeballs, take a look at your lighting situation. It's good idea to keep your room evenly lit while avoiding screen glare as much as possible. You don't want light coming from directly behind your display (I say, with a window behind my desk) or pointed directly at it. And though it's unlikely that you have florescent lights above your desk, avoid those.
"On average, a person going through his or her daily routine blinks about 18 times per minute. However, spending significant amounts of time staring at a screen causes blink rates to reduce, resulting in dry, itchy or burning eyes."
Eye drops may help, or you could put a Blink-182 poster above your display to remind yourself (may backfire as Mark Hoppus's smirk is known to cause bewildered, unblinking staring).
If everything but the game and your glasses is black and white, I'm not sure what's going on with your eyes.
If just taking eye breaks and reminding yourself that pop punk was a thing isn't helpful, one option is to try a product like Gunnar glasses, which filter artificial blue light and are said to help relax the ciliary muscles. I'm skeptical of all health products marketed to me on the internet, but I know people who swear by them. Ars Technica had a pretty good experience with the glasses, and confirmed with an optometrist that they are beneficial, but also noted that you may be able to find a cheaper pair that does the same thing. Dr. Hawkeswood was more skeptical. I say: if they work for you, that's great! They're at least worth a try if you have constant eye strain problems, though it is a lot of money to spend when better lighting and more breaks may be all you need.
But before buying special glasses, go to an optometrist. You may need corrective lenses, and you should be getting regular check ups anyway (like, more than once every five years, which I have a terrible habit of doing). It doesn't matter if you've had perfect vision your whole life—I can say from experience that my astigmatism has altered my vision into my late 20s.
But assuming your eyes are healthy and you're only experiencing minor headaches (if you're taking medication for headaches more than twice a week, Mayo Clinic suggests that you see a physician), here's one last tip: try f.lux. It isn't exactly designed to alleviate eye strain, but it feels worth mentioning anyway. F.lux is a lightweight program that adjusts the color temperature of your screen according to the time of day, mimicking daylight during the day, and warming it to the temperature indoor lighting at night. It's primarily said to benefit sleep, as recent research suggests that looking at blue light before bed can keep you up, but I find it makes my screen generally easier to look at. It may not help with gaming (you'd want to warm up your display's color settings for that), but I love it when I'm working.
As for gaming alone, here's the recap: keep your room evenly lit (ideally not with florescent lights), but not so bright as to cause glare. Look away from your display every 20 minutes or so and focus on something distant. Don't forget to blink. And see an optometrist—if the optometrist looks blurry, you probably need corrective lenses. Ask the optometrist about that once you find her.
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