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Producing electricity from marine renewable resources is a research area that develops continuously. The field of tidal energy is on the edge to progress from the prototype stage to the commercial stage. However, tidal resource characterization, and the effect of tidal turbines on the flow, is still an ongoing research area in which this thesis aims to contribute.
In this thesis, measurements of flow velocities have been performed at three kinds of sites. Firstly, a tidal site has been investigated for its resource potential in a fjord in Norway. Measurements have been performed with an acoustic Doppler current profiler to map the spatial and temporal characteristics of the flow. Results show that currents are in the order of 2 m/s in the center of the channel. Furthermore, the flow is highly bi-directional between ebb and flood flows. The site thus has potential for in-stream energy conversion. Secondly, a river site serves as an experimental site for a marine current energy converter that has been designed at Uppsala University and deployed in Dalälven, Söderfors. The flow rate at the site is regulated by an upstream hydro power plant, making the site suitable for experiments on the performance of the vertical axis turbine in a natural environment. The turbine was run in steady discharge flows and measurements were performed to characterize the extent of the wake. Lastly, at an ocean current site, the effect that transiting ferries may have on submerged devices was investigated. Measurements were conducted with two sonar systems to obtain an underwater view of the wake caused by a propeller and a water jet thruster respectively.
Furthermore, the variability of the intermittent renewable sources wind, solar, wave and tidal energy was investigated for the Nordic countries. All of the sources have distinctly different variability features, which is advantageous when combining power generated from them and introducing it on the electricity grid. Tidal variability is mainly due to four aspects: the tidal regime, the tidal cycle, local bathymetry causing turbulence, asymmetries etc. and weather effects. Models of power output from the four sources was set up and combined in different energy mixes for a "highly renewable" and a "fully renewable" scenario. By separating the resulting power time series into different frequency bands (long-, mid-, mid/short-, and short-term components) it was possible to minimize the variability on different time scales. It was concluded that a wise combination of intermittent renewable sources may lower the variability on short and long time scales, but increase the variability on mid and mid/short time scales.
The tidal power variability in Norway was then investigated separately. The predictability of tidal currents has great advantages when planning electricity availability from tidal farms. However, the continuously varying tide from maximum power output to minimum output several times per day increases the demand for backup power or storage. The phase shift between tidal sites introduces a smoothing effect on hourly basis but the tidal cycle, with spring and neap tide simultaneously in large areas, will inevitably affect the power availability.
Measurements of tidal current water velocities is an important first step in evaluating the potential for a tidal site to be used as a renewable energy resource. For this reason, on site measurements are performed at the inlet of a fjord situated at the coast of Norway. The site has an average width of 580 m and adepth of 10-15 m which is narrow and shallow enough to give rise to water velocities that can be of use for energy conversion. With the use of an Acoustic Doppler Current Profiler (ADCP) cross-section measurements are conducted along four transects. The measurements covered flood and ebb currents around one tide and the data give a first approximation of the magnitude and distribution of the flow field. Depth averaged mean current velocities are calculated along the transects for horizontal bins with sizes in the order of 50 x 50 m. Maximum mean velocity for the flood currents were 1.31 m/s and 1.46 m/s for the ebb currents. The measurements show that even a small amount of data can give an indication of the potential and characteristics ofthe site.
For tidal-stream energy industry to be fully realized, lower velocity sites and fjords should be developed. Finding new prospective sites for in-stream energy extraction from tidal currents is an area of ongoing research. In this paper, the tidal flow at a fjord inlet has been characterized using acoustic Doppler current profiler (ADCP) measurements. This work is based on two survey measurement techniques: transect measurements to map the spatial variability, and seabed measurements to map the temporal variability. The data was analyzed in terms of characterizing metrics, to ensure they are comparable with other resource assessments. Results show that currents exceed 1 m/s for 38% of the time with peak currents of 2.06 m/s at hub height (middle of the water column) and the directional asymmetry is less than 1° between ebb and flood, indicating a truly bi-directional flow. A simple prediction model is proposed which allows peak current speeds to be accurately predicted in the channel center from tidal range data using a linear relationship. The relationship is shown to be strong, with a correlation coefficient of 0.98 at hub height, and a standard variation typically less than 10 cm/s. Furthermore, it is show that a minimum of 9 days of measurements are required to set up the model, although it takes 29 days to reduce the error in peak speed to less than 1%. However, the error is expected to vary depending on where in the monthly tidal cycle the survey begins, it is thus recommended to measure around spring tide if the measurement period is short.
The Division of Electricity at Uppsala University recently deployed an experimental hydrokinetic power station for in-stream experiments at a site in a river. This paper briefly describes the deployment process and reports some initial results from measurements made at the test site.
Wake characteristics of marine current turbines are of significant importance to the development of the marine current power source. Turbine wake recovery determines spacing of turbines in arrays, and environmental impact on e.g. the seabed is heavily influenced by wake behaviour. The majority of previous studies on wakes has been performed on flow-aligned (horizontal) axis turbines and mainly carried out as scale model experiments or numerical simulations.
This paper describes the performance of wake measurements at the Söderfors test site, where an experimental marine current power station is operated in a river. The turbine is of the cross-flow (vertical) axis type, and the measurements are performed using an Acoustic Doppler Current Profiler (ADCP) towed on the surface by a boat. Positioning data is taken from a high-accuracy Global Navigation Satellite System. The paper discusses various aspects of the methodology employed and provides examples of taken measurements.
Increasing the share of intermittent renewable energy (IRE) resources such as solar, wind, wave and tidal energy in a power system poses a challenge in terms of increased net load variability. Fully renewable power systems have previously been analysed, but more systematic analyses are needed that explore the effect of different IRE mixes on system-wide variability across different timescales and the optimal combinations of IRE for reducing variability on a given timescale. Here we investigate these questions for the Nordic power system. We show that the optimal mix of IRE is dependent on the frequency band considered. Long-term (>4 months) and short-term (<2 days) fluctuations can be similar to today's, even for a fully renewable system. However, fluctuations with periods in between will inevitably increase significantly. This study indicates that, from a variability point of view, a fossil- and nuclear-free Nordic power system is feasible if properly balanced by hydropower.
Tidal currents provide an intermittent source of renewable energy. A high degree of intermittency is unfavorable in the existing power system. However, by aggregating tidal power from sites with variable tidal phase a more firm power outpu tmay be achieved. In this paper, the tidal current phasing between 114 potential tidal energy sites along the Norwegian coast is investigated. Time series of tidal currents are generated with a model that considers the variation in current strength due to the variability in the semi-diurnal tidal cycle (spring to neap, flood to ebb, first to second daily tide etc.). From these, available kinetic energy in the natural flow is calculated. A constant conversion rate is then applied to give the power output at each site. Three scenarios, with varying number of sites and energy extraction, are investigated. The variability in each scenario is quantified on different time scales by filtering the aggregated power and calculate standard deviation and step change. It is found that the variability can be lowered by choosing sites with an advantageous time lag and limit the power output from the most energetic sites. As expected, smoothing is most distinct on short time scales.
Symbiosis brought important evolutionary novelties to life on Earth. Lichens, the symbiotic entities formed by fungi, photosynthetic organisms and bacteria, represent an example of a successful adaptation in surviving hostile environments. Yet many aspects of the lichen symbiosis remain unexplored. This thesis aims at bringing insights into lichen biology and the importance of symbiosis in adaptation. I am using as model system a successful colonizer of tundra and alpine environments, the worm lichens Thamnolia, which seem to only reproduce vegetatively through symbiotic propagules. When the genetic architecture of the mating locus of the symbiotic fungal partner was analyzed with genomic and transcriptomic data, a sexual self-incompatible life style was revealed. However, a screen of the mating types ratios across natural populations detected only one of the mating types, suggesting that Thamnolia has no potential for sexual reproduction because of lack of mating partners. Genetic data based on molecular markers revealed the existence of three morphologically cryptic Thamnolia lineages. One lineage had a clear recombination structure and was found in the tundra region of Siberia, shorelines of Scandinavia, and Aleutian Islands. The other lineage was allopatric with the previous, and was highly clonal; only two haplotypes were found across the alpine region of central and southeastern Europe. However, the third lineage was sympatric with the other two, had a worldwide distribution, and although highly clonal, showed a recombinant population structure. Our data could not reveal whether the signs of recombination resulted from rare recombination events due to the extreme low frequency of the other mating type or ancestral variation before the loss of sexual reproduction. However, investigation of Thamnolia's green algal population showed that in different localities, different algal genotypes were associated with the same fungal genotype. Furthermore, data suggest that Thamnolia carried several algal genotypes within its thalli and shared them with other distantly related but ecologically similar fungal species.
Thamnolia is a lichenized fungus with an extremely wide distribution, being encountered in arctic and alpine environments in most continents. In this study, we used molecular markers to investigate the population structure of the fungal symbiont and the associated photosynthetic partner of Thamnolia. By analyzing molecular, morphological, and chemical variation among 253 specimens covering the species distribution range, we revealed the existence of three mycobiont lineages. One lineage (Lineage A) is confined to the tundra region of Siberia and the Aleutian Islands, a second (Lineage B) is found in the high alpine region of the Alps and the Carpathians Mountains, and a third (Lineage C) has a worldwide distribution and covers both the aforementioned ecosystems. Molecular dating analysis indicated that the split of the three lineages is older than the last glacial maximum, but the distribution ranges and the population genetic analyses suggest an influence of last glacial period on the present-day population structure of each lineage. We found a very low diversity of Lineage B, but a higher and similar one in Lineages A and C. Demographic analyses suggested that Lineage C has its origin in the Northern Hemisphere, possibly Scandinavia, and that it has passed through a bottleneck followed by a recent population expansion. While all three lineages reproduce clonally, recombination tests suggest rare or past recombination in both Lineages A and C. Moreover, our data showed that Lineage C has a comparatively low photobiont specificity, being found associated with four widespread Trebouxia lineages (three of them also shared with other lichens), while Lineages A and B exclusively harbor T. simplex s. lat. Finally, we did not find support for the recognition of taxa in Thamnolia based on either morphological or chemical characters.
Safety and reliability are one of the key objectives for future Generation IV nuclear energy systems. The neutron flux monitoring system forms an integral part of the safety design of a nuclear reactor and must be able to detect any irregularities during all states of reactor operation. The work in this thesis mainly concerns the detection of in-core perturbations arising from unwanted movements of control rods with in-vessel neutron detectors in a sodium-cooled fast reactor. Feasibility study of self-powered neutron detectors (SPNDs) with platinum emitters as in-core power profile monitors for SFRs at full power is performed. The study shows that an SPND with a platinum emitter generates a prompt current signal induced by neutrons and gammas of the order of 600 nA/m, which is large enough to be measurable. Therefore, it is possible for the SPND to follow local power fluctuations at full power operation. Ex-core and in-core detector locations are investigated with two types of detectors, fission chambers and self-powered neutron detectors (SPNDs) respectively, to study the possibility of detection of the spatial changes in the power profile during two different transient conditions, i.e. inadvertent withdrawal of control rods (IRW) and one stuck rod during reactor shutdown (OSR). It is shown that it is possible to detect the two simulated transients with this set of ex-core and in-core detectors before any melting of the fuel takes place. The detector signal can tolerate a noise level up to 5% during an IRW and up to 1% during an OSR.
The neutron flux monitoring system forms an integral part of the safety design of a Generation IV sodium-cooled fast reactor. During the initial design phase of the neutron flux monitoring system, one needs to explore various detector locations and configurations. Diverse possibilities of the detector system installation should be studied for different locations in the reactor vessel in order to detect any perturbations in the core. In this paper, we investigate the possibility of placing fission chambers beyond the lateral neutron shield, ex-core but in-vessel and study the detectability of an inadvertent control rod withdrawal with these fission chambers. A generic core design of a Generation IV 1500 MWth French sodium-cooled fast reactor is used for the study, and calculations are performed with the Monte Carlo code SERPENT2. We propose certain design changes that are needed to be incorporated, w.r.t. the facilitation of neutron transport to this ex-core location.
We are able to show that there is a detectable signature in the fission chambers following an inadvertent control rod withdrawal in the core. The equally-spaced azimuthal detectors are able to follow changes in the neutron flux distribution in the core. This study helps us to analyze multiple detector locations and give the general trends for monitoring indications to detect any perturbations in the core.
Safety and reliability are essential requirements for development and operation of SodiumcooledFast Reactors. Development of a neutron flux monitoring system (NFMS) for the FrenchSFR is one of the key R&D areas identified. Diverse possibilities of detector system installationshould be studied for different locations in the reactor vessel in order to detect any perturbations inthe core. In this paper, we aim to explore two calculation routes available for neutron flux monitoring,assess them for their efficiency to detect fission rate variation at Above-core structure (ACS)location and discuss the associated pros and cons. The two calculational approaches we refer hereare criticality mode and external source mode. We discuss the feasibility of choosing this locationfor detecting in-core perturbations and evaluate the methodology needed to achieve it. The paperfocuses on the difficulties associated with neutron detection when the detectors are located at far-offdistances from the source. We found that for a difficult case such as ours where the detectors arelocated far-away from the source, criticality mode doesn't work. Variance reduction techniques,employed in the external source mode are indispensable to drive neutrons to areas of interest.
The neutron flux monitoring system of the FrenchGEN-IV sodium-cooled fast reactor will rely on hightemperaturefission chambers installed in the reactor vessel andcapable of operating over a wide-range neutron flux. Thedefinition of such a system is presented and the technologicalsolutions are justified with the use of simulation andexperimental results.
This thesis aims to provide insight into the fundamental electrochemical processes taking place when cycling SnO2 in lithium-ion batteries (LIBs). Special attention was paid to the partial reversibility of the tin oxide conversion reaction and how to enhance its reversibility. Another main effort was to pinpoint which limitations play a role in tin based electrodes besides the well-known volume change effect in order to develop new strategies for their improvement. In this aspect, Li+ mass transport within the electrode particles and the large first cycle charge transfer resistance were studied. Li+ diffusion was proven to be an important issue regarding the electrochemical cycling of SnO2. It was also shown that it is the Li+ transport inside the SnO2 particles which represents the largest limitation. In addition, the overlap between the potential regions of the tin oxide conversion and the alloying reaction was investigated with photoelectron spectroscopy (PES) to better understand if and how the reactions influence each other`s reversibility.
The fundamental insights described above were subsequently used to develop strategies for the improvement of the performance and the cycle life for SnO2 electrodes in LIBs. For instance, elevated temperature cycling at 60 oC was employed to alleviate the Li+ diffusion limitation effects and, thus, significantly improved capacities could be obtained. Furthermore, an ionic liquid electrolyte was tested as an alternative electrolyte to cycle at higher temperatures than 60 oC which is the thermal stability limit for the conventional LP40 electrolyte. In addition, cycled SnO2 nanoparticles were characterized with transmission electron microscopy (TEM) to determine the effects of long term high temperature cycling. Also, the effect of vinylene carbonate (VC) as an electrolyte additive on the cycling behavior of SnO2 nanoparticles was studied in an effort to improve the capacity retention. In this context, a recently introduced intermittent current interruption (ICI) technique was employed to measure and compare the development of internal cell resistances with and without VC additive.
As tin based electrodes are of significant interest in the development of improved lithium-ion batteries it is important to understand the associated electrochemical reactions. In this work it is shown that the electrochemical behavior of SnO2 coated tin electrodes can be described based on the SnO2 and SnO conversion reactions, the lithium tin alloy formation and the oxidation of tin generating SnF2. The CV, XPS and SEM data, obtained for electrodeposited tin crystals on gold substrates, demonstrates that the capacity loss often observed for SnO2 is caused by the reformed SnO2 layer serving as a passivating layer protecting the remaining tin. Capacities corresponding up to about 80 % of the initial SnO2 capacity could, however, be obtained by cycling to 3.5 V vs. Li+/Li. It is also shown that the oxidation of the lithium tin alloy is hindered by the rate of the diffusion of lithium through a layer of tin with increasing thickness and that the irreversible oxidation of tin to SnF2 at potentials larger than 2.8 V vs. Li+/Li is due to the fact that SnF2 is formed below the SnO2 layer. This improved electrochemical understanding of the SnO2/Sn system should be valuable in the development of tin based electrodes for lithium-ion batteries.
The performance of lithium-ion batteries (LIBs) comprising SnO2 electrodes and an ionic liquid (IL) based electrolyte, i.e., 0.5 MLiTFSI in Pip14TFSI, has been studied at room temperature (i.e., 22◦C) and 80◦C. While the high viscosity and low conductivity ofthe electrolyte resulted in high overpotentials and low capacities at room temperature, the SnO2 performance at 80◦C was found to beanalogous to that seen at room temperature using a standard LP40 electrolyte (i.e., 1MLiPF6 dissolved in 1:1 ethylene carbonate anddiethyl carbonate). Significant reduction of the IL was, however, found at 80◦C, which resulted in low coulombic efficiencies duringthe first 20 cycles, most likely due to a growing SEI layer and the formation of soluble IL reduction products. X-ray photoelectronspectroscopy studies of the cycled SnO2 electrodes indicated the presence of an at least 10 nm thick solid electrolyte interphase (SEI)layer composed of inorganic components such as lithium fluoride, sulfates, and nitrides as well as organic species containing C-H,C-F and C-N bonds.
In-house and synchrotron-based photoelectron spectroscopy (XPSand HAXPES) evidence is presented for an overlap between the conversion andalloying reaction during the cycling of SnO2 electrodes in lithium-ion batteries(LIBs). This overlap resulted in an incomplete initial reduction of the SnO2 as wellas the inability to regenerate the reduced SnO2 on the subsequent oxidative scan.The XPS and HAXPES results clearly show that the SnO2 conversion reactionoverlaps with the formation of the lithium tin alloy and that the conversion reactiongives rise to the formation of a passivating Sn layer on the SnO2 particles. The latterlayer renders the conversion reaction incomplete and enables lithium tin alloy toform on the surface of the particles still containing a core of SnO2. The results alsoshow that the reoxidation of the lithium tin alloy is incomplete when the formationof tin oxide starts. It is proposed that the rates of the electrochemical reactions andhence the capacity of SnO2-based electrodes are limited by the lithium masstransport rate through the formed layers of the reduction and oxidations products.In addition, it is shown that a solid electrolyte interphase (SEI) layer is continuously formed at potentials lower than about 1.2 VLi+/Li during the first scan and that a part of the SEI dissolves on the subsequent oxidative scan. While the SEI was found tocontain both organic and inorganic species, the former were mainly located at the SEI surface while the inorganic species werefound deeper within the SEI. The results also indicate that the SEI dissolution process predominantly involves the organic SEIcomponents.
Large resources are invested in healthcare research, but despite this there is a wide gap between research knowledge and healthcare practice. Implementation researchers have addressed this gap, focusing mostly on the role of healthcare practitioners. However, a narrow focus on implementation does not take into consideration the preceding stages and the roles of different actors during the whole innovation process, which starts from research and ends with implementation. The aim of this thesis is to examine the behaviors of three key actors during an innovation process and to explore the influence of selected contextual factors on their behavior.
Study I (n=10 funders) identifies several facilitative roles for funders and suggests that implementation risks becoming no one's responsibility as the funders identify six different actors responsible for implementation, the majority of whom embody a collective or an organization. Study II finds that the implementation knowledge of Swedish funding managers (n=18) is mostly based on experience-based knowledge. The majority of the funding managers define implementation as a process and express limited knowledge of implementation. The findings of Study III (n=4 innovation cases) show that the roles and involvement of academic inventors and ISAs (innovation-supporting actors) are more connected to intellectual property (IP) nature than to intellectual property rights (IPR) ownership. Study IV (n=4 innovation cases) identifies three different logics that influence the behavior of academic inventors: market, academic and care logics. A pattern emerges where the behavior of academic inventors is guided by a unique logic and there is no interaction between logics, despite the existence of multiple logics. The individual strategies to handle multiple logics coincide with the influence of logics. In addition, IP nature, distinguishing between high-tech and low-tech innovations, is connected to the influence of institutional logics: low-tech connected to the care logic and high-tech connected to the market logic.
This thesis has three main theoretical and practical implications relevant for practitioners, policymakers and researchers. First, implementation responsibility is an important issue to study and discuss, because without clearly defined responsibilities and management of responsibilities, responsibility might become no one's responsibility. Second, the finding that experience-based implementation knowledge contributes heavily to policymakers' knowledge encourages further studies and discussions regarding this relatively neglected issue. Third, the importance of IP nature in shaping innovation processes should be considered and further examined, not only as a factor influencing inventors and ISAs' roles and involvement, but also as influencing the prevalence of different institutional logics. Further, the relevance of a distinction between low-tech and high-tech IP should be reflected on.
Implementation of clinical research results is challenging, yet the responsibility for implementation is seldom addressed. The process from research to the use of clinical research results in health care can be facilitated by research funders. In this paper, we report the roles of ten Swedish research funders in relation to implementation and their views on responsibilities in implementation.
Ten cases were studied and compared using semi-structured interviews. In addition, websites and key documents were reviewed. Eight facilitative roles for research funders in relation to the implementation of clinical research results were identified. Three of them were common for several funders: "Advocacy work," "Monitoring implementation outcomes," and "Dissemination of knowledge." Moreover, the research funders identified six different actors responsible for implementation, five of which belonged to the healthcare setting. Collective and organizational responsibilities were the most common forms of responsibilities among the identified actors responsible for implementation.
The roles commonly identified by the Swedish funders, "Advocacy work," "Monitoring implementation outcomes," and "Dissemination of knowledge," seem feasible facilitative roles in relation to the implementation of clinical research results. However, many actors identified as responsible for implementation together with the fact that collective and organizational responsibilities were the most common forms of responsibilities entail a risk of implementation becoming no one's responsibility.
In Cu(In,Ga)Se2 (CIGS) solar cells the CIGS layer serves as the light absorber, growing naturally p-type. Together with an n-type buffer layer they form a p-n heterojunction. Typically, CdS is used as a buffer, although other, less toxic materials are investigated as alternatives. The intrinsic p-type doping of CIGS layers is the result of complex defect physics. Defect formation energies in CIGS are very low or even negative, which results in extremely high defect concentrations. This leads to many unusual electrical phenomena that can be observed in CIGS devices. This thesis mostly focuses on three of these phenomena: light-soaking, light-on-bias, and light-enhanced reverse breakdown.
Light-soaking is a treatment that involves illuminating the investigated device for an extended period of time. In most CIGS solar cells it results in an improvement of open-circuit voltage, fill factor, and efficiency that can persist for hours, if not days. The interplay between light-soaking and the remaining two phenomena was studied. It was found that light-soaking has a strong effect on light-on-bias behavior, while the results for light-enhanced breakdown were inconclusive, suggesting little to no impact.
Light-on-bias is a treatment which combines simultaneous illumination and application of reverse bias to the studied sample. Illuminating CdS-based samples with red light while applying a reverse bias results in a significant increase in capacitance due to filling of traps. In many cases, this is accompanied by a decrease in device performance under red illumination. Complete recovery is possible by illuminating the treated sample with blue light, which causes hole injection from the CdS buffer. In samples with alternative buffer layers, there is little distinction between red and blue illumination, and the increase in capacitance is milder. At the same time, there is little effect on device performance.
Reverse breakdown can occur when a sufficiently large reverse bias is applied to a p-n junction, causing a large reverse current to flow through the device. In CIGS solar cells, the voltage at which breakdown occurs in darkness decreases in the presence of blue illumination. A model explaining the breakdown in darkness was proposed as a part of this thesis. The model assumes that all voltage drops on the buffer layer in darkness and on the CIGS layer under blue illumination. The high electric field in the buffer facilitates Poole-Frenkel conduction and Fowler-Nordheim tunneling between the absorber and the buffer.
Partial shading of solar modules can subject shaded cells to significant reverse bias, often large enough toforce them into electrical breakdown, possibly resulting in irreversible damage. Therefore, better understandingof reverse current–voltage characteristics might lead to improvements in the design of solar modules. Thefocus of this study is the breakdown behavior of Cu(In,Ga)Se2 (CIGS) cells in darkness and under illumination.Two series of CIGS cells were investigated, with CdS and Zn–Sn–O buffer layers of varying thickness. Electricalbreakdown was found to be highly dependent on the buffer layer. Under blue illumination a remarkable decreasein breakdown voltage was observed for both buffer types. Metastable defects in the buffer/CIGS interfaceregion are tentatively proposed as the source of this effect and tunnelling is suggested as the mainmechanism responsible for breakdowns.
Cu(In,Ga)Se-2 thin-film solar cells with Ga-graded absorber layers and a [Cu]/([In] + [Ga]) ratio varying between 0.5 and 1.0 were prepared by coevaporation and investigated. Except for the sample with a final [Cu]/([In] + [Ga]) ratio of 1.0, the samples were Cu-poor at all times during the evaporation. The variation in copper was found to influence the material properties in several ways: 1) Changing the Cu content had a strong impact on In and Ga interdiffusion, resulting in decreased Ga gradients in samples with large Cu deficiency; 2) the Cu-poor Cu(In, Ga)(3)Se-5 phase was detected in absorbers with [Cu]/([In] + [Ga]) ratios of 0.65 and below; and 3) the grain size changed significantly with the Cu variation. We observe a trend of reduced solar cell efficiencies for [Cu]/([In] + [Ga]) ratios of 0.65 and below, with an efficiency of 13.4% for the sample with a [Cu]/([In] + [Ga]) ratio of only 0.5, i.e., far from stoichiometry. We tentatively attribute the efficiency loss to a high concentration of point defects caused by the Cu deficiency.
The chemical properties of calcium phosphate cements (CPCs) are very similar to the mineral phase of bone. CPCs are, consequently, very effective substrates (scaffolds) for tissue engineering; bone and stem cells attach readily, and can proliferate and differentiate to form new bone tissue. Unlike other CPCs that may remain largely unchanged in the body for years, such as hydroxyapatite, dicalcium phosphates are remodelled by the body and rapidly converted to new bone. Unfortunately, the dicalcium phosphates are also typically too weak to support load bearing in the human body. Our laboratory has recently developed a novel, high strength brushite CPC, (hsCPC), which can reach 10-50 fold higher failure strength than many commercially available CPCs. The aim of this thesis was to investigate the physical, chemical and biological performance of hsCPCs in physiologically relevant model of drug release, load bearing, osteoconductivity, and as a scaffold for bone tissue engineering.
Multiple CPCs were compared in a model of screw augmentation to determine whether the physical properties of the cement, such as bulk strength and porosity, affected orthopaedic screw holding strength. In an in vitro model of bone regeneration stem cells were grown on macroporous scaffolds that were fabricated from hsCPC. Drug releasing scaffolds were fabricated to examine whether the low porosity of hsCPC impeded drug release during a 4-week incubation period. The biological activity of an incorporated drug, Rebamipide, was examined after acute and chronic incubation periods. In the drug release study it was noted that the biological response to hsCPC was significantly greater than tissue culture grade polystyrene, even in scaffold groups without drug. The mechanism underlying this biological response was further investigated by testing the effect of pyrophosphate, a common cement additive, on bone cell proliferation and differentiation. This thesis concludes that a high strength cement can produce significant improvement in screw augmentation strength, if there is sufficient cortical bone near the augmentation site. The hsCPC is also cytocompatible, and can support bone and stem cell proliferation and differentiation. hsCPC scaffolds stimulated osteogenic gene expression comparable to native bone scaffolds. hsCPC scaffolds are also capable of delivering drug for up to 4 weeks, in vitro. Finally, a cement additive, pyrophosphate, stimulated differentiation but not proliferation of bone cells.
Disease and injuries that affect the skeletal system may require surgical intervention and internal fixation, i.e. orthopedic plate and screw insertion, to stabilize the injury and facilitate tissue repair. If the surrounding bone quality is poor the screws may migrate, or the bone may fail, resulting in screw pull-out. Though numerous studies have shown that cement augmentation of the interface between bone and implant can increase screw holding strength in bone, the physical properties of cement that influence pull-out force have not been investigated. The present study sought to determine how the physical properties of calcium phosphate cements (CPCs), and the strength of the biological or synthetic material surrounding the augmented screw, affected the corresponding orthopedic screw pull-out force in urethane foam models of healthy and osteoporotic bone (Sawbones). In the simplest model, where only the bond strength between screw thread and cement (without Sawbone) was tested, the correlation between pull-out force and cement compressive strength (R2 = 0.79) was weaker than correlation with total cement porosity (R2 = 0.89). In open pore Sawbone that mimics "healthy" cancellous bone density the stronger cements produced higher pull-out force (50-60% increase). Higher strength, lower porosity, cements also produced higher pull-out forces (50-190% increase) in Sawbones with cortical fixation if the failure strength of the cortical material was similar to (bovine tibial bone), or greater than (metal shell), actual cortical bone. This result is of particular clinical relevance where fixation with a metal plate implant is indicated, as the nearby metal can simulate a thicker cortical shell and, thereby, increase the pull-out force of screws augmented with stronger cements. The improvement in pull-out force was apparent even at low augmentation volumes of 0.5 ml (50% increase), which suggest that in clinical situations where augmentation volume is limited the stronger, lower porosity CPCs may still produce a significant improvement in screw holding strength. When correlations of all the tested models were compared both cement porosity and compressive strength accurately predicted pull-out force (R2=1.00, R2=0.808), though prediction accuracy depended upon the strength of the material surrounding the Sawbone. The correlations strength was low for bone with no, or weak, cortical fixation. Higher strength and lower porosity CPCs also produced greater pull-out force (1-1.5 kN) than commercial CPC (0.2-0.5kN), but lower pull-out force than PMMA (2-3 kN). The results of this study suggest that the likelihood of screw fixation failure may be reduced by selecting calcium phosphate cements with lower porosity and higher bulk strength, in patients with healthy bone mineral density and/or sufficient cortical thickness. This is of particular clinical relevance when fixation with metal plates is indicated, or where the augmentation volume is limited.
Pyrophosphate is a potent mitogen, capable of stimulating proliferation in multiple cell types, and a critical participant in bone mineralization. Pyrophosphate can also affect the resorption rate and bioactivity of orthopedic ceramics. The present study investigated whether calcium pyrophosphate affected proliferation, differentiation and gene expression in early (MC3T3 pre-osteoblast) and late stage (SAOS-2 osteosarcoma) osteoblasts. Pyrophosphate stimulated peak alkaline phosphatase activity by 50% and 150% at 100 mu M and 0.1 mu M in MC3T3, and by 40% in SAOS-2. The expression of differentiation markers collagen 1 (COL1), alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCN) were increased by an average of 1.5, 2, 2 and 3 fold, by high concentrations of sodium pyrophosphate (100 mu M) after 7 days of exposure in MC3T3. COX-2 and ANK expression did not differ significantly from controls in either treatment group. Though both high and low concentrations of pyrophosphate stimulate ALP activity, only high concentrations (100 mu M) stimulated osteogenic gene expression. Pyrophosphate did not affect proliferation in either cell type. The results of this study confirm that chronic exposure to pyrophosphate exerts a physiological effect upon osteoblast differentiation and ALP activity, specifically by stimulating osteoblast differentiation markers and extracellular matrix gene expression.
Many of the bioactive agents capable of stimulating osseous regeneration, such as bone morphogenetic protein-2 (BMP-2) or prostaglandin E2 (PGE2), are limited by rapid degradation, a short bioactive half-life at the target site in vivo, or are prohibitively expensive to obtain in large quantities. Rebamipide, an amino acid modified hydroxylquinoline, can alter the expression of key mediators of bone anabolism, cyclo-oxygenase 2 (COX-2), BMP-2 and vascular endothelial growth factor (VEGF), in diverse cell types such as mucosal and endothelial cells or chondrocytes. The present study investigates whether Rebamipide enhances proliferation and differentiation of osteoblasts when delivered from brushite cement. The reactive oxygen species (ROS) quenching ability of Rebampide was tested in macrophages as a measure of bioactivity following drug release incubation times, up to 14 days. Rebamipide release from brushite occurrs via non-fickian diffusion, with a rapid linear release of 9.70%+/- 0.37% of drug per day for the first 5 days, and an average of 0.5%-1% per day thereafter for 30 days. Rebamipide slows the initial and final cement setting time by up to 3 and 1 minute, respectively, but does not significantly reduce the mechanical strength below 4% (weight percentage). Pre-osteoblast proliferation increases by 24% upon exposure to 0.4uM Rebamipide, and by up to 73% when Rebamipide is delivered via brushite cement. Low doses of Rebamipide do not adversely affect peak alkaline phosphatase activity in differentiating pre-osteoblasts. Rebamipide weakly stimulates proliferation in macrophages at low concentrations (118 +/- 7.4% at 1uM), and quenches ROS by 40-60%. This is the first investigation of Rebamipide in osteoblasts.
Calcium phosphate cements (CPCs) have been extensively used in reconstructive dentistry and orthopedics, but it is only recently that CPCs have been combined with stem cells to engineer biological substitutes with enhanced healing potential. In the present study, macroporous CPC scaffolds with defined composition were fabricated using an easily reproduced synthesis method, with minimal fabrication and processing steps. Scaffold pore size and porosity, essential for cell infiltration and tissue ingrowth, were tuned by varying the content and size of polyethylene glycol (PEG) particles, resulting in 9 groups with different architectural features. The scaffolds were characterized for chemical composition, porosity and mechanical properties, then tested in vitro with human mesenchymal progenitors derived from induced pluripotent stem cells (iPSC-MPs). Biomimetic decellularized bone scaffolds were used as reference material in this study. Our manufacturing process resulted in the formation of macroporous monetite scaffolds with no residual traces of PEG. The size and content of PEG particles was found to affect scaffold porosity, and thus mechanical properties. Irrespective of pore size and porosity, the CPC scaffolds fabricated in this study supported adhesion and viability of human iPSC-MPs similarly to decellularized bone scaffolds. However, the architectural features of the scaffolds were found to affect the expression of bone specific genes, suggesting that specific scaffold groups could be more suitable to direct human iPSC-MPs in vitro toward an osteoblastic phenotype. Our simplistic fabrication method allows rapid, inexpensive and reproducible construction of macroporous CPC scaffolds with tunable architecture for potential use in dental and orthopedic applications.
Cerebral small vessel disease (SVD) is identifiable by clinical, neuroimaging, neuropathological and cognitive findings.
The aim of this thesis was to assess SVD and cerebral perfusion on magnetic resonance imaging (MRI) in a 75-year-old population and compare the findings with scars of myocardial infarctions, cardiovascular risk markers and cognitive function. In addition, the evolution of SVD over 5 years was studied.
The study population included subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. The subjects had been chosen in a randomized manner from the register of the municipality. MRI of the brain and the heart, cognitive tests and blood tests for cardiovascular risk factors were performed in 406 subjects at age 75 years and 250 of them were re-examined 5 years later at the age of 80.
Paper 1 showed that unrecognized myocardial infarctions (UMIs) were found in 120 subjects (30%) and recognized myocardial infarctions (RMIs) in 21 (5%). Men with RMIs displayed an increased prevalence of cortical and lacunar cerebral infarctions, whereas women with UMIs more frequently had cortical cerebral infarctions.
Paper 2 showed that one or more brain infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts and 2% had both). Hypertension and obesity were significantly associated with an increased risk of infarction. The newer risk markers investigated were not significantly associated with brain infarcts.
Paper 3 showed that MRI manifestations of SVD progressed over 5 years. Relative cerebral blood flow (rCBF) was not associated with WMH volume or progression of WMH volume.
Paper 4 showed that moderate to severe WMHs and incident lacunar infarcts on brain MRI were associated with a mild impairment of executive function.
In conclusion, this longitudinal population based study compares MRI manifestations of SVD with clinical data, providing knowledge that may be used in further investigations of preventive interventions and for identification of disease in early stages.
OBJECTIVES: The purpose of this study was to investigate the prevalence of unrecognized myocardial infarction (UMI) detected with magnetic resonance imaging (MRI) and whether it is related to cerebral ischemic lesions on MRI in an elderly population-based cohort.
BACKGROUND: There is a correlation between stroke and recognized myocardial infarction (RMI) and between stroke and UMI detected with electrocardiography, whereas the prevalence of stroke in subjects with MRI-detected UMI is unknown.
METHODS: Cerebral MRI and cardiac late-enhancement MRI were performed on 394 randomly selected 75-year-old subjects (188 women, 206 men). Images were assessed for cerebral ischemic lesions and myocardial infarction (MI) scars. Medical records were scrutinized. Subjects with MI scars, with or without a hospital diagnosis of MI, were classified as RMI or UMI, respectively.
RESULTS: UMIs were found in 120 subjects (30%) and RMIs in 21 (5%). The prevalence of UMIs (p = 0.004) and RMIs (p = 0.02) was greater in men than in women. Men with RMI displayed an increased prevalence of cortical and lacunar cerebral infarctions, whereas women with UMI more frequently had cortical cerebral infarctions (p = 0.003).
CONCLUSIONS: MI scars are more frequent in men than in women at 75 years of age. The prevalence of RMI is related to that of cerebral infarctions.
Established cardiovascular risk markers, such as hypertension, are associated with increased risk of brain infarcts. The newer markers N-terminal pro-brain natriuretic peptide, troponin I, C-reactive protein, and cystatin C may affect the risk of cardiovascular events and potentially, thereby, also stroke. We investigated the association between established and new risk markers for cardiovascular disease and brain infarcts detected by magnetic resonance imaging (MRI) at age 75.
Four hundred six randomly selected subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors study were examined with MRI of the brain at age 75. Blood samples, measurements, and dedicated questionnaires at age 70 were used for analysis of risk markers. A history of diseases had been obtained at age 70 and 75. MRI was evaluated regarding lacunar and cortical infarcts. Univariate associations between outcomes and risk markers were assessed with logistic regression models.
One or more infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts, and 2% had both). Hypertension (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.4, 4.7) and obesity (OR 1.3; CI 1.0, 1.8) were significantly associated with increased risk of brain infarction. The newer risk markers were not significantly associated with the brain infarcts.
The new markers were not associated with the predominantly lacunar infarcts in our 75-year-old population, why troponin I and NT-proBNP may be associated mainly with cardioembolic infarcts as shown recently.
During the last decades, Swedish policy makers have implemented various marketization reforms into the public welfare sector in order to make it more cost-efficient and to improve its quality. The aim of this dissertation is to investigate what implications this marketization trend has had for the organization of Swedish eldercare. In particular, the research question addressed is how marketization reforms such as privatized provision, increased competition, and user choice have transformed the relationship between the service users, the professionals, and the state. To answer the research question, four articles are presented in the dissertation, each corresponding to a separate empirical investigation. Together, the articles demonstrate that the increased reliance on marketization in Swedish eldercare has made it more difficult for the local authorities to directly control the quality of the services, since it reduces their ability to allocate public resources and expects them to govern the provision of eldercare through the entering of contracts. This development has also implied that service users themselves become increasingly responsible for ensuring that the quality of their care is high. Moreover, the articles show that the increased reliance on audit by the national government and its agencies has tended to undermine the professionalization of eldercare staff, thereby limiting their autonomy and ability to ensure service quality. As a whole, the dissertation contributes with a more comprehensive understanding of how marketization has altered the organization of Swedish eldercare and under what conditions it might undermine the goals of social equality and ensuring that all citizens have equal access to good quality care.
Proponents of user choice argue that this type of policy arrangement improves the quality of public social services since users are expected to select the most highly performing providers. In order for users to make informed choices, however, they need quality information about the services offered by different providers. In this article, we carry out a case study, investigating whether information about service quality was presented to users of home-based elderly care in Sweden. The analysis is based on unique data regarding the information of 223 providers in 10 municipalities. The results suggest that the information was poor and lacking in important quality dimensions. This indicates a lack of real user power since it is virtually impossible for users to make informed choices without relevant information. It also makes it less likely that the general quality level of home-based services will increase as a result of the user choice.
The objective of this article is to analyse whether the increased reliance on marketisation in the provision of social care challenges the universality of eldercare in Sweden, Denmark, Finland and Norway. The study focuses on national reforms for contracting out and user choice of provider, analysing their consequences for four universalistic dimensions: (i) equal inclusion, (ii) public funding, (iii) public provision and (iv) comprehensive usage. The findings suggest that, although need-based inclusion and public funding remain key principles in all four countries, there is an increased reliance on private provision in Sweden, Denmark and Finland. In addition, the introduction of topping-up services challenges the dimension of comprehensive usage by enabling users with economic resources to turn to the private market to increase the comprehensiveness and quality of their care.
The objective of this article is to analyze whether the audit processes adopted in Swedish eldercare and childcare support or undermine the professionalization of the occupations working there, that is, nurses, nursing assistants, pre-school teachers and child minders. In particular we investigate whether the three main forms of audit; standard-setting, inspections and quality measurements, support or undermine the occupations' ability to achieve professional closure and enhance their external and internal autonomy. The paper finds that the audit process adapted in eldercare is non-supportive of the professionalization of both nurses and nursing assistants. In childcare, however, it appears to support professional development, particularly for pre-school teachers. These findings suggest that audit processes do not have to be detrimental to professionalization. Instead, it appears that the state can design them in such a way that they make visible and close the work tasks of specific staff groups and thereby support, rather than undermine, their professional development
This article aims to analyze how the policy makers who crafted the Swedish choice reform in eldercare reasoned with regard to the tension between user choice and citizens' right to quality care. To answer this question, three dimensions are addressed in the paper: (i) what role did the choice reform assign to the users and how did the policy makers view their ability to make informed choices? (ii) How did the policy makers view the role of the public authorities and what tools were they given to ensure citizens' equal access to good quality eldercare? (iii) Did the policies entail a new form of social citizenship for the elderly? The findings suggest that while Swedish policy makers introduced a system where eldercare users were encouraged to make free choices between providers, thereby allocating resources among these, the users also became more responsible to ensure service quality through their choices. In addition, the choice reform altered the regulatory role of local authorities who no longer had full control over the resource distribution and also become more restricted in their regulatory abilities. Furthermore, the paper argues that the Swedish choice reform entails a more libertarian notion of social citizenship, implying that users are to take on greater responsibility for their own well-being and protection against social risks.
Background: Insufficient exposure assessment is a suggested contributing factor to the current lack of clearly characterised relationships between occupational biomechanical risk factors and musculoskeletal disorders. Minimal attention has been paid to the potential bias of measurement tools from expected true values (i.e. accuracy) or between measurement tools, and empirical data on the magnitudes of variance contributed by methodological factors for measurement tool precision are lacking.
Aim: The aim of this thesis was to quantify aspects of bias and precision in three commonly employed biomechanical risk factor assessment tools - inclinometry, observation, and electromyography (EMG) - and provide recommendations guiding their use.
Methods: Upper arm elevation angles (UAEAs) were assessed using inclinometers (INC) and by computer-based posture-matching observation, and bias relative to true angles was calculated. Calibration models were developed for INC data, and their efficacy in correcting measurement bias was evaluated. The total variance of trapezius and erector spinae (ES) EMG recordings during cyclic occupational work was partitioned into biological and methodological sources, including the variance uniquely attributable to sub-maximal normalisation. Using algorithms to estimate the precision of a group mean, the efficacy of different trapezius EMG study designs was evaluated. Using precision criteria, the efficacy of different normalisation methods was assessed for ES EMG recordings.
Results and Discussion: Inclinometer measured UAEAs were biased from true angles, with increasing bias at higher angles. In contrast, computer based posture-matching observations were not biased from true angles. Calibration models proved effective at minimizing INC data bias. The dispersion of estimates between- and within- observers at any given set angle underlined the importance of repeated observations when estimating UAEAs. For EMG, a unique but relatively small component of the total variance was attributable to the methodological process of normalisation. Performing three repeats of the trapezius EMG normalisation task proved optimal at minimizing variance for one-day EMG studies, while two repeats sufficed for multi-day EMG studies. A prone normalisation task proved superior for maximizing normalised lumbar ES EMG precision.
Conclusion: Key aspects of measurement tool accuracy, bias between tools, and tool precision were quantified, and recommendations were made to guide future research study design.
Previous research suggests inclinometers (INC) underestimate upper arm elevation. This study was designed to quantify possible bias in occupationally relevant postures, and test whether INC performance could be improved using calibration. Participants were meticulously positioned in set arm flexion and abduction angles between 0 degrees and 150 degrees. Different subject-specific and group-level regression models comprising linear and quadratic components describing the relationship between set and INC-registered elevation were developed using subsets of data, and validated using additional data. INC measured arm elevation showed a downward bias, particularly above 600. INC data adjusted using the regression models were superior to unadjusted data; a subject-specific, two-point calibration based on measurements at 0 and 900 gave results closest to the 'true' set angles. Thus, inclinometer measured arm elevation data required calibration to arrive at 'true' elevation angles. Calibration to a common measurement scale should be considered when comparing arm elevation data collected using different methods.
Selecting a suitable body posture measurement method requires performance indices of candidate tools. Such data are lacking for observational assessments made at a high degree of resolution. The aim of this study was to determine the performance (bias and between- and within-observer variance) of novice observers estimating upper arm elevation postures assisted by posture matching software to the nearest degree from still images taken under ideal conditions. Estimates were minimally biased from true angles: the mean error across observers was less than 2. Variance between observers was minimal. Considerable variance within observers, however, underlined the risk of relying on single observations. Observers were more proficient at estimating 0 and 90 postures, and less proficient at 60. Thus, under ideal visual conditions observers, on average, proved proficient at high resolution posture estimates; further investigation is required to determine how non-optimal image conditions, as would be expected from occupational data, impact proficiency.
OBJECTIVES: To quantify the variance introduced to trapezius electromyography (EMG) through normalization by sub-maximal reference voluntary exertions (RVE), and to investigate the effect of increased normalization efforts as compared to other changes in data collection strategy on the precision of occupational EMG estimates.
METHODS: Women performed four RVE contractions followed by 30 min of light, cyclic assembly work on each of two days. Work cycle EMG was normalized to each of the RVE trials and seven exposure parameters calculated. The proportions of exposure variance attributable to subject, day within subject, and cycle and normalization trial within day were determined. Using this data, the effect on the precision of the exposure mean of altering the number of subjects, days, cycles and RVEs during data collection was simulated.
RESULTS: For all exposure parameters a unique component of variance due to normalization was present, yet small: less than 4.4% of the total variance. The resource allocation simulations indicated that marginal improvements in the precision of a group exposure mean would occur above three RVE repeats for EMG collected on one day, or beyond two RVEs for EMG collected on two or more days.
Aim: The object of this study was to quantify the contribution of sub-maximal normalisation to the overall variance of exposure parameters describing erector spinae (ES) activity, and to provide guidelines for task selection which minimize methodological variance. Methods: ES EMG was measured from three locations (T9, L1 and L5 levels) on fifteen men performing a manual materials handling task in the laboratory on three separate days. Four repeats of each of eleven sub-maximal normalisation tasks (eight static, three dynamic) were collected, work data were normalised to each task and repeat, and exposure parameters calculated. The unique contribution of normalisation to the overall variance was determined for each task and exposure parameter using variance component analyses. Normalisation tasks were scored according to their relative contributions to the overall variance and coefficients of variation.
Results: A prone task, similar to the Biering-Sørensen test posture, was the most repeatable for all electrode locations and across all exposure parameters. Thoracic level normalisation typically showed poorer repeatability than lumbar normalisation.
Discussion: We recommend that future ES EMG studies employing sub-maximal normalisation utilise said prone task. An alternate normalisation task specific to thoracic level ES muscles may be warranted.
The Extended Evolutionary Synthesis (EES) is currently emerging as a theoretical alternative to the Modern Synthesis (MS) in which to frame evolutionary observations and interpretations. These alternative frameworks differ fundamentally in their understanding of the relative roles of the genotype, phenotype, development and environment in evolutionary processes and patterns. While the MS represents a gene-centred view of evolution, the EES instead emphasizes the interactions between organism, development and environment. This novel theoretical framework has generated a number of evolutionary predictions that are mutually incompatible with the equivalent of the MS. While research and empirical testing has begun on a number of these in a neontological context, the field of palaeontology has yet to contribute meaningfully to this endeavour. One of the reasons for this is a lack of methodological approaches capable of investigating relevant evolutionary patterns in the fossil record. In this thesis morphometric methods capable of providing relevant data are developed and employed in the analysis of Cambrian fossils. Results of these analyses provide empirical support for the process of evolution through phenotypic plasticity and genetic assimilation hypothesized by the EES. Furthermore, theoretical revision to the species concept in a palaeontological context is suggested. Finally, predictions of the EES specific to the fossil record are made explicit and promising directions of future research are outlined.
The study of evolution in a palaeontological context is chiefly the study of change in shape and form. This requires data sets that quantify morphology and morphological variation. Historically morphology has been described using discrete characters or more recently using various morphometric approaches. Elliptical Fourier analysis (EFA) is an approach to quantifying morphology that results in the production of large data sets of elliptical Fourier descriptors (EFDs), which are highly suitable to multivariate analysis. EFA is used in this paper to quantify the shape and describe the ontogeny of Agnostus pisiformis (Wahlenberg 1818: Nova Acta Regiae Societatis Scientiarum Upsaliensis 8, 1), a trilobite-like arthropod of Cambrian Series 3, from three coeval localities in Sweden. An ontogenetic difference was detected between geographically distant populations from Västergötland and Skåne in Sweden. These differences are probably the result of environmental dysoxic stress leading to increasing phenotypic variation. These findings illustrate the utility of EFA applied to the study of fossil organisms; permitting studies of such high resolution that multiple assemblages of the same species can be comparatively studied to achieve a more detailed understanding of their morphological and ontogenetic variation.
Phylogenetic relationships within the helcionelloids have been difficult to establish. One of the reasons for this is that qualitative approaches to investigating morphological variation in this group have struggled to identify clear patterns. An alternative method of identifying these patterns is to study these organisms quantitatively. Here we exemplify this approach by employing morphometric methods to investigate patterns of subtle morphological variation in two species of Mackinnonia Runnegar in Bengtson et al. Specifically, we conduct a combination of elliptical Fourier and multivariate analyses to study intra- and interspecific variation in protoconch form and variation in ontogenetic trajectory of two species of Mackinnonia. The material we use consists of two assemblages of Mackinnonia rostrata (Zhou & Xiao), from the Shackleton Limestone of Antarctica and Ajax Limestone of Australia, and an assemblage of Mackinnonia taconica (Landing & Bartowski) from the Bastion Formation of Greenland. Results of our study show significant (p=<0.0001) differences in protoconch shape between all three groups. Ontogenetic sequences of outline curves truncated at successive rugae significantly (p=<0.05) discriminate between M. rostrata and M. taconica. We discuss the uncovered significant intraspecific morphological variation of disparate assemblages of M. rostrata despite shared qualitative features and develop a conceptual framework for understanding such patterns of variation. We define the incipient species concept using Mackinnonia as an empirical example.
Genetic assimilation is a hypothesised process in which an initially plastic developmental phenotypic response of an organism to the environment is fixed genetically, i.e. assimilated into its genome 1,2. One central prediction of genetic assimilation is that "phenotypic accommodation can precede, rather than follow, genetic change, in adaptive evolution"3. Here we test this prediction in the fossil record. Agnostus pisiformis, a Cambrian Series 3 trilobite-like arthropod, has been shown to exhibit subtly different patterns of pygidial morphological variation across coeval assemblages4, varying chiefly in the degree to which the axial lobe dominates the pygidium. We demonstrate that this morphological variation as well as that of the slightly younger closely related Homagnostus obesus is significantly correlated with geochemical indicators of dysoxia/euxinia and thus stressed environments5-7. In addition, the variances of high and low-stress assemblages also differ significantly, suggesting that the morphological variability of the different assemblages is induced by environmental stress and can be understood as a reaction norm8. We include in our analysis the younger relative Trilobagnostus holmi and interpret its morphology, which has a strongly reduced variance, as representing a more canalized9 or stabilized1 stage of the assimilation process. Thus our data contain all stages of adaptation via phenotypic plasticity and genetic assimilation10 and support the main predictions of the 'Extended Evolutionary Synthesis'3.
The Extended Evolutionary Synthesis (EES) has recently emerged as a theoretical alternative or complement to the Modern Synthesis (MS) in which to frame evolutionary observations and interpretations. The theoretical framework of the EES places a greater evolutionary significance on a number of controversial hypotheses and processes, such as phenotypic plasticity and genetic assimilation, and makes a number of empirical predictions based thereon. Investigation and empirical exploration of these predictions has begun in a neontological context yet the field of palaeontology has not yet been instrumental in developing or testing these predictions. Here the hypothetical process of evolution via phenotypic plasticity and genetic assimilation is explained and contextualised to the fossil record. A prediction of the EES specific to palaeontological data is formulated and methods suitable for its empirical testing are suggested.
This thesis presents experimental results on strongly interacting γ-Fe2O3 magnetic nanoparticles and their collective properties. The main findings are that very dense randomly packed (≈60%) γ-Fe2O3 nanoparticles form a replica of a spin glass. The magnetic properties of the nanoparticle system are in most regards the same as those of an atomic spin glass. The system is therefore proposed as a model superspin glass. In superspin glasses the interacting building blocks that form the collective state are single domain nanoparticles, superspins with a magnetic moment of about 10000 μB, which can be compared to the atomic magnetic moment in spin glasses of approximately 1 μB. It was found that the relaxation time of the individual nanoparticles impacts the collective properties and governs the superspin dimensionality. Several dense compacts, each prepared with nanoparticles of a specific size, with diameters 6, 8, 9 and 11.5 nm, were studied. All the studied compacts were found to form a superspin glass state. Non-interacting reference samples, consisting of the same particles but coated with a silica shell, were synthesized to determine the single particle magnetic properties. It was also found that the effects of the nanoparticle size distribution, which lead to a variation of the magnetic properties, can be mitigated by having strong enough interparticle interactions. The majority of the work was carried out using SQUID magnetometry.
Magnetization dynamics of a model superspin glass system consisting of nearly monodispersed close-packed maghemite particles of diameter 8 nm is investigated. The observed non-equilibrium features of the dynamics are qualitatively similar to those of atomic spin glass systems. The intrinsic relaxation function, as observed in zero-field-cooled magnetization relaxation experiments, depends on the time the sample has been kept at constant temperature (ageing). Accompanying low-field experiments show that the archetypal spin glass characteristics -ageing, memory and rejuvenation- are reproduced in this dense system of dipolar-dipolar interacting superspins.
The question of the dominant interparticle magnetic interaction type in random closely packed assemblies of different diameter (6.2-11.5 nm) bare maghemite nanoparticles (NPs) is addressed. Single-particle magnetic properties such as particle anisotropy and exchange bias field are first of all studied in dilute (reference) systems of these same NPs, where interparticle interactions are neglible. Substantial surface spin disorder is revealed in all particles except the smallest, viz. for diameters d = 8-11.5 nm but not for d = 6.2-6.3 nm. X-ray diffraction analysis points to a crystallographic origin of this effect. The study of closely packed assemblies of the d >= 8 nm particles observes collective (superspin) freezing that clearly appears to be governed by interparticle dipole interactions. However, the dense assemblies of the smallest particles exhibit freezing temperatures that are higher than expected from a simple (dipole) extrapolation of the corresponding temperatures found in the d >= 8 nm assemblies. It is suggested that the nature of the dominant interparticle interaction in these smaller particle assemblies is superexchange, whereby the lack of significant surface spin disorder allows this mechanism to become important at the level of interacting superspins.
Dense random assemblies made from highly monodisperse gamma-Fe2O3 nanoparticles with sizes ranging from 6.2 to 11.5 nm have been investigated by DC and AC magnetometry. It is found that all assemblies undergo superspin glass phase transitions. The superspin glass phase transition temperature is strongly dependent on the particle size and the nature of the interparticle interaction. However the transition from superparamagnet to superspin glass, as evidenced by the shape of the ac-susceptibility curves and the dynamic critical exponents associated with the transition, is similar in all systems.
The low temperature dynamic magnetic properties of two dense magnetic nanoparticle assemblies with similar superspin glass transition temperatures T-g similar to 140 K are compared. The two samples are made from batches of 6 and 8 nm monodisperse gamma-Fe2O3 nanoparticles, respectively. The properties of the individual particles are extracted from measurements on reference samples where the particles have been covered with a thick silica coating. The blocking temperatures of these dilute assemblies are found at 12.5 K for the 6 nm particles and at 35 K for the 8 nm particles, which implies different anisotropy energy barriers of the individual particles and vastly different temperature evolution of their relaxation times. The results of the measurements on the concentrated particle assemblies suggest a strong influence of the particle energy barrier on the details of the aging dynamics, memory behavior, and apparent superspin dimensionality of the particles.
We highlight the relevance of demagnetizing-field corrections in the characterization of dense magnetic nanoparticle assemblies. By an analysis that employs in-plane and out-of-plane magnetometry on cylindrical assemblies, we demonstrate the suitability of a simple analytical formula-based correction method. This allows us to identify artifacts of the demagnetizing field in temperature-dependent susceptibility curves (e.g., shoulder peaks in curves from a disordered assembly of essentially bare magnetic nanoparticles). The same analysis approach is shown to be a straightforward procedure for determining the magnetic nanoparticle packing fraction in dense, disordered assemblies.
This dissertation examines young people's reading of fiction in the digital age, with a special focus on the aspects of attitude and competence. The literary reading of respondents in their upper teens is considered from several perspectives—especially those of the respondents themselves. The discussion is based on three larger empirical studies of the reading attitudes and practices of 18-year-olds. These studies build on and complement each other in relation to the overarching research questions through a triangulating process combining qualitative and quantitative methods. The studies are, however, freestanding and were conducted using different empirical methods.
The first study is diachronic in that it compares national test essays on the topic of reading from the year 2000 with essays written according to the same instructions twelve years later. The main aim of this study is to reveal possible differences between the two generations in terms of attitudes and approaches to reading fiction, and to relate them to issues of literary legitimization and competence. The second study consists of a questionnaire about a short story read by the respondents, as well as about their general reading and media habits. A connection is drawn between media habits and reading frequency, on the one hand, and the results of the essay study, on the other. The respondents' reception and understanding of the story is analyzed separately. A summary of the first two studies reveals several complex issues with contradictory patterns. The third study, which examines these issues more closely, was conducted through focus-group interviews. All three studies have been carried out among groups of pupils in the third year of upper secondary school in Sweden.
The final part of the dissertation summarizes the results of the three studies, applying a pedagogical perspective to literature pedagogy within the subject of Swedish at the upper secondary level. This discussion points out several opportunities for literature teachers today.
The theoretical studies of several magnetic materials are presented in this thesis. To each of them, it was investigated the electronic structure, by means of density functional theory calculations, and/or magnetization dynamics, in the context of atomistic spin dynamics (ASD). For bulk properties, we evaluate the magnon spectra of the heavy rare earths (Gd, Tb, Dy, Ho, Er, and Tm), using the exchange parameters and magnetic moments from first-principles calculations in ASD simulations. Additionally, we performed Monte Carlo simulations that nicely reproduced the qualitative trend of lowering of the critical temperatures across the series. Next, we discuss about the microscopic mechanism of the vanishingly low magnetic anisotropy of Permalloy using the concept of the orbital moment anisotropy for Fe and Ni atoms in the alloy. Turning to surface magnetism, we discuss the use of exchange parameters computed by a noncollinear formalism for 6 monolayers of Fe on the Ir(001) substrate, in order to have a more accurate description of magnons at finite temperature and to obtain good comparison with experimental data. Besides that, we also studied surface magnons on 3 and 9 Ni monolayers on Cu(001) and Cu(111) in order to track the significant surface and/or interface effects and contrast it to properties that are fcc Ni bulk-like. Likewise, we used the Monte Carlo method to estimate the critical temperatures of Ni surfaces and compared with experimental data. Finally, in the field of low dimensional magnetism, we present the ab-initio calculations for the electronic structure of Cr nanostructures of diverse geometries adsorbed on the Pd(111) surface, with focus on the formation of non-collinear spin configurations, either due to geometric frustration or the spin-orbit coupling provided by the substrate.
We evaluate how thermal effects soften the magnon dispersion in 6 layers of Fe(001) on top of Ir(001). We perform a systematic study considering noncollinear spin arrangement and calculate configuration-dependent exchange parameters J(ij)(nc) following the methodology described by Szilva et al. [Phys. Rev. Lett. 111, 127204 (2013)]. In addition, Monte Carlo simulations were performed in order to estimate the noncollinear spin arrangement as a function of temperature. Hence the J(ij)(nc)'s related to these configurations were calculated and used in an atomistic spin dynamics approach to evaluate the magnon spectra. Our results show good agreement with recent room-temperature measurements, and highlights how thermal effects produce magnon softening in this, and similar, systems.
We report on the electronic structure, magnetic moments and exchange interactions of one-and two-dimensional Cr clusters on a Pd(1 1 1) substrate, using a real-space method based on density functional theory in the local spin density approximation. We find in general that for the investigated clusters, the magnetic moments are sizeable and almost entirely of spin-character. We demonstrate that the interactions in general are dominated by nearest-neighbor antiferromagnetic Heisenberg form, which implies that Cr on Pd(1 1 1) forms an ideal model system, in which clusters of almost any shape and size can be investigated from a Heisenberg Hamiltonian, using a nearest-neighbor exchange model. We have also found that complex magnetic structures can be realized for linear chains of Cr, due to a competition between exchange interaction and a weaker Dzyaloshinskii-Moriya interaction.
This thesis is about 16 newly arrived students from Iraq enrolled in the introductory programme for newcomers, in two Swedish upper secondary schools during the academic year 2010/11. The study focuses on the newly arrived students' possession of cultural, social, educational and linguistic capital and their migration experience as well as their plans for future studies. The theoretical framework is based on the sociology of Pierre Bourdieu and research in International Migration and Ethnic Relations (IMER). Of crucial importance is the sociologist Abdelmalek Sayad, who bridges Bourdieu and migration studies. Also, general sociological concepts like class, gender and ethnicity are used. Traditional ethnographic approaches such as observations, informal conversations and interviews are the main methods.
The empirical results show that the newly arrived students have varying degrees of inherited assets, although the majority came from more affluent backgrounds. They also differed with regard to their school background. The ones who went to public schools in Iraq described the Iraqi educational system as authoritarian institution in which they had to conform to collective norms and values. Those who went to private international schools reported that their schools were similar to those in Sweden, but significantly more demanding. The youths also had assets that had little value in the Swedish educational system. One example is the ability to speak several languages like Arabic, Kurdish, Syriac and Chaldean.
Newly arrived students usually have no experience of the Swedish school system and cannot speak Swedish. This limitation defines them as a disadvantaged group when they enter the Swedish educational system, in programmes specially designed for them. Furthermore, the newly arrived students are spatially and symbolically segregated from other students and are thus poorly integrated in into the schools' ordinary activities. The newly arrived students quickly become aware of that they do not master the language and that they are not familiar with the study norms and roles in Sweden. However, the students express high educational aspirations and emphasize education as a key factor in achieving respectability. Or, in Bourdieu's sense, success in the Swedish educational system represents symbolic capital, for the Swedish born population as well as for as members of their own ethnic group.
Chlorins, as the core structures of chlorophylls, have been extensively studied for harvesting solar energy, fluorescent imaging and photodynamic therapy against cancer. This thesis is concerned with design and synthesis of novel chlorins as antennae for harvesting light and sensitising near infrared lanthanide luminescence.
In the first part, a series of chlorin monomers, dimers and polymers were synthesised and their photophysical properties were characterised. The chlorin monomers were substituted with five-membered heterocycles, such as thiophenes and furans. These heterocycles function as auxochromes analogous to the natural ones in chlorophylls, and extend chlorin absorption and emission strongly to the red (up to λem = 680 nm). A borylation method was developed to prepare borylated chlorins, which gave access to directly linked chlorin dimers through Suzuki coupling reaction. Different regioisomers of chlorin dimer were prepared, including β-meso homodimers, meso-meso homodimers and heterodimers. The dimerisation resulted in red-shifted absorption and emission. Chlorin polymerisations were performed both electrochemically and chemically. Bis-thienylchlorins yielded chlorin films and an organic solvent soluble copolymer with hexylthiophene, respectively. These polymers from both polymerisations have red absorptions beyond 700 nm, and might be used as light-harvesting antennae.
In the second part, chlorins were used as chromophores to sensitise near infrared lanthanide luminescence. Two types of chlorin-lanthanide dyads were prepared through lanthanide coordination with cyclen derivatives and dipicolinic acids (DPA). The cyclen-based dyads were poorly soluble in water, thus their near infrared emissions were not observed. The other type of complexes was fully soluble in H2O and THF. Both Nd and Yb emission were recorded even upon excitation into the Q bands of chlorins. In the dyads with free base chlorins, the singlet state of chlorins might be involved in the sensitisation of lanthanide luminescence. These DPA-based dyads presented two-color emission based on one chlorin and two-color excitation based on one lanthanide ion. These dyads would enable in theory 4-color imaging.
In the last part, a microwave-assisted two-step synthesis was described to prepare dipyrromethanes, which are the key intermediates in the chlorin synthesis. This mild method took advantage of the nucleophilicity of pyrrole and the electrophilicity of N,N-dimethylaminomethyl pyrroles. The usually used acid catalysis is detrimental to many functionalities, thus our methods enable the synthesis of dipyrromethanes with acid sensitive groups or a formyl group.
The de novo syntheses of chemically stable chlorins with five-membered heterocyclic (furane, thiophene, formylfurane and formylthiophene) substituents in selected meso- and beta-positions are reported. Heterocycle incorporation in the 3- and 13-positions shifted the chlorin absorption and emission to the red (up to lambdaem =680 nm), thus these readily incorporated substituents function analogously to auxochromes present in chlorophylls, for example, formyl and vinyl groups. Photophysical, theoretical and X-ray crystallographic experiments revealed small but significant differences between the behavior of the furan- and the thiophene-based auxochromes. Four regioisomeric bis-thienylchlorins (3,10; 3,13, 3,15 and 10,15) were oxidatively electropolymerized; the chlorin monomer geometry had a profound impact on the polymerization efficiency and the electrochemical properties of the resulting material. Chemical co-polymerization of 3,13-bis-thienylchlorin with 3-hexylthiophene yielded an organic-soluble red-emitting polymer.
Directly linked hydroporphyrin (chlorin) dimers were accessed regioselectively from bromochlorins. Versatile 15-borylated chlorins were prepared in excellent yield via Miyaura borylation. Suzuki coupling yielded meso-beta-linked homo- and heterodimers, and meso-blinked dimers. The photophysical and electrochemical properties of the dimers are reported.
Fluorescence spectroscopy is in many ways the ideal tool for the interrogation of complex biological systems, as it is non-invasive, sensitive, and offers high spatiotemporal resolution. For biomedical imaging luminescent probes absorbing and emitting in the red-to-near infrared (NIR) region are best suited to maximise tissue penetration and minimise damage to cellular components. NIR-emitting lanthanides (Ln) sensitised with red-absorbing antennae are promising candidates for these applications, assuming the challenges of poor photophysical properties and tedious syntheses of the complexes are overcome. Chlorins are porphyrin-type tetrapyrroles with intense red absorption. Recently chlorins have been shown to sensitise Yb and Nd emission when incorporated into Ln-complexes. Here we expand on our previous work, and explore the effect of chlorin structure, metallation state, chlorin-Ln-complex linker length and mode of attachment on the properties of chlorin-Ln complexes. As chlorin absorption bands are approximately 20 nm fwhm and readily tunable, a deeper understanding of structure-property relationships would enable the use of chlorin-Ln complexes in multicolour imaging using antenna-specific excitation. A detailed description of antenna and complex syntheses and photophysical characterisation is given. A number of challenges were identified, which will have to be addressed in future studies to enable multicolour imaging using the NIR-emitting lanthanides.
: Multiplex luminescence imaging in the red and near infrared (NIR) should be an enabling tool for the real-time investigation of complex biological systems. Current probes have numerous limitations including low photostability, short luminescent lifetime, overlapping absorption and emission bands, and small Stokes shift, the combination of which limits multiplexing in this region to two colors. Here we report emitters based on near infrared (NIR) emitting luminescent lanthanides (Ln) sensitized by hydroporphyin antennae. The narrow and intense absorption bands of hydroporphyrins are in the red, and their porisiotns are readily tunable. These dyads enable both emission- and excitation-based multiplexing; the former by combining either the same antenna with different Ln's, the latter by attaching chlorin antennae with non-overlapping absorptions to the same Ln-complex. Up to 4 different species could be discerned without tedious data manipulation.
The Mannich reaction between pyrroles or indoles and Eschenmoser's salt (dimethylmethylideneammonium iodide) forms N,N-dimethylamino-methylated derivatives in good to excellent yields. The reaction is highly regioselective, and for pyrroles both 2- and 3-sub- stituted derivatives could be obtained. The N,N-dimethylaminometh- ylpyrroles and indoles underwent substitution with pyrrole under mi- crowave irradiation, affording the appropriate dipyrromethanes, N- confused, and indolo-dipyrromethanes in moderate to excellent overall yield.
This thesis investigates the multiple and contested spaces of belonging that may be evoked by ritualised musical performance. It makes an ethnographic case study of the Zorn Badge Auditions in Sweden, in which musicians play before a jury in the hope of being awarded a Zorn Badge and a prestigious but also contested title: Riksspelman.
Building on theories of ritual and performance in combination with Sara Ahmed's theorisation of orientation, the thesis attends to sensory ways of experiencing and knowing music while tracing the various ways in which Swedish traditional music is performed, felt, heard, sensed and understood in audition spaces. It draws on interviews with players and jury members, participant observations of music auditions and the jury's deliberations, showing how musical value is negotiated through processes of inclusion and exclusion of repertoires, instruments and performance practices. The study also illuminates how anxiety and uncertainties are felt on both sides of the adjudication table. The auditions trigger feelings of belonging and harmony, but also rupture and distance. A brimming of felt qualities contributes to the sensing of history, tradition, memory, place and geography, as well as close emotional connections between music and individual performers. The thesis reveals how gradual adaptation, and the lived experiences of time within tradition, allow the Zorn institution to negotiate change and thereby maintain its position within Swedish society.
This thesis presents genetic studies aiming at enlarging our knowledge regarding the genetic factors underlying two immune-mediated diseases, hypothyroidism and autoimmune Addison's disease (AAD), in dogs and humans, respectively.
Genetic and environmental factors are indicated to contribute to canine hypothyroidism, which can be considered a model for human Hashimoto's thyroiditis (HT). In Paper I we performed the first genome-wide association (GWA) study of this disease in three high-risk dog breeds (Gordon Setter, Hovawart and Rhodesian Ridgeback). Using an integrated GWA and meta-analysis strategy, we identified a novel hypothyroidism risk haplotype located on chromosome 12 being shared by the three breeds. The identified haplotype, harboring three genes previously not associated with hypothyroidism, is independent of the dog leukocyte antigen region and significantly enriched across the affected dogs. In Paper II we performed a GWA study in another high-risk breed (Giant Schnauzer) and detected an associated locus located on chromosome 11 and conferring protection to hypothyroidism. After whole genome resequencing of a subset of samples with key haplotypes, we fine mapped the region of association that was subsequently screened for the presence of structural variants. We detected a putative copy number variant overlapping with the upstream region of the IFNA7 gene, which is located in a region of high genomic complexity. Remarkably, perturbed activities of type I Interferons have been extensively associated with HT and general autoimmunity.
In Paper III we performed the first large-scale genetic study of human AAD, a rare autoimmune disorder characterized by dysfunction and ultimately destruction of the adrenal cortex. We resequenced 1853 immune-related genes comprising of their coding sequences, untranslated regions, as well as conserved intronic and intergenic regions in extensively characterized AAD patients and control samples, all collected in Sweden. We identified BACH2 gene as a novel risk locus associated with AAD, and we showed its independent association with isolated AAD. In addition, we confirmed the previously established AAD association with the human leukocyte antigen complex.
The results of these studies will hopefully help increasing the understanding of such diseases in dogs and humans, eventually promoting their well-being.


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The 4th Symposium on Riordan Arrays and Related Topics (4RART) will be held at Universidad Complutense de Madrid in Madrid on 17-20 July 2017.
The aims of this meeting are to share ideas and results related to Riordan matrices developed by researchers all around the world and to gather together specialists in different areas where the Riordan group or any of its elements is or could be involved.
This symposium follows the line established by the three previous ones.
Web pages of previous symposia:
Scientific committee
Local organizing committee

subset: commoncrawl


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|Jennifer Blanc
|Kierston Wareing
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|Tom Wilkinson
|Michael Fairman
|Chris Young
|Ross Thomas
|Courtney Peldon
|Jack Riley
|Jon Glaser
|Lisa Cholodenko
|Todd Louiso
|Afton Williamson
There either is or is not, that's the way things are. The colour of the day. The way it felt to be a child. The saltwater on your sunburnt legs. Sometimes the water is yellow, sometimes it's red. But what colour it may be in memory, depends on the day. I'm not going to tell you the story the way it happened. I'm going to tell it the way I remember it.
The Lizzie Bennet Diaries is an innovative, original episodic video and social media series produced for the web. Adapting Pride and Prejudice to the modern era, Lizzie Bennet tells the classic Jane Austen tale from the point of view of an Elizabeth "Lizzie" Bennet who grew up in a world of cell phones, video cameras, and social media. The series was created by popular YouTube personality Hank Green and Streamy Award winning web video writer Bernie Su.
The holiday season is bringing more than cheer for actress Jessica Capshaw. The Grey's Anatomy star announced on Monday that she and her husband, Honest Company co-founder Christopher Gavigan, are expecting their fourth child. "The holidays have certainly arrived … All of our lives are being added to by the lights, the music and cheer!!" she captioned a photo of her family at a Christmas tree farm on Instagram. "This year our family has reason to further broaden our smile … baby number four is on the way!! I am a lucky, lucky girl…"
The quickest way to tell whether an actor is serious about his or her career is to look at their "headshot".Is it a professional photo? Or is it a snapshot taken on prom night? If you're using a snapshot, it's like showing up to race the Indy 500 in a VW Beetle. Nobody is going to take you seriously. I'm sorry, people… you can send me as much angry e-mail as you want about this, but it's true! Don't tell me you're destined to be a major Hollywood star but you cannot scrape together the cash to get professional headshots.
The Grinch from Dr. Seuss' How the Grinch Stole Christmas! The Musical stole the spotlight at the Empire State Building's 86th Floor Observatory December 14, 2012, to promote the musical's limited holiday engagement. Discover the magic of Dr. Seuss' classic holiday tale as it comes to life on stage. Featuring the hit songs "You're A Mean One, Mr. Grinch" and "Welcome Christmas," The Grinch discovers there's more to Christmas then he bargained for in this heart-warming holiday classic.
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