677 research outputs found

    An Analysis Of Theoni Aldredge\u27s Life And Career

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    This thesis examines the life and career of costume designer Theoni Aldredge. Using her extensive career and connections to the theatrical field observations will be made regarding some interactions fashion and technology have with costuming, as well as defining qualities of performance genres

    Geochemistry of volcanic rocks from the Sunda Arc

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    Geochemical analyses of igneous rocks can provide valuable information about processes, element fluxes, and rock lithologies not evident at the surface. This is particularly important in subduction zone settings where complex interactions between the subducting plate, mantle wedge and arc crust cannot yet be measured by alternative methods. The Sunda arc, in SE Asia, provides an ideal opportunity to study the effects of subduction in a complex tectonic setting where the basement is poorly exposed and understood. However, in order to do so, magma compositions modified during differentiation in the arc crust must be effectively distinguished from those modified at the source. This study includes a detailed major- and trace element and isotopic (Sr-Nd-Hf-Pb) examination of volcanoes from west Java (Papandayan, Patuha and Galunggung), Central Java (Sumbing), east Java (Kelut) and Bali (Agung), the result of which provides greater insights into petrogenesis both across and along the arc. Contamination in the arc crust is more extensive than previously recognised, particularly in west and central Java where few volcanoes can be used in order to identify subduction and source contributions. In west Java, volcanoes such as Papandayan and Patuha show significant enrichments in isotope ratios above mantle values (e.g. 87Sr/86Sr ~ 0.706, 143Nd/144Nd ~ 0.5125, 208Pb/204Pb ~ 18.91 and 176Hf/177Hf ~ 0.2827) which indicates a terrigneous crustal contaminant. At Sumbing volcano, most magma compositions are similar to those at Merapi and Merbabu, and show strong evidence for the assimilation of carbonate-rich lithologies with some magmas becoming enriched in CaO, Sr and 87Sr/86Sr. Differentiation in volcanoes from east Java and the western part of the Lesser Sunda Islands (Bali, Lombok and Sumbawa) is dominantly controlled by fractional crystallisation, which provides better controls on source compositions. At Kelut, one group of samples show the most ‘depleted’ magma compositions yet discovered on Java, which contain MORB-like values for 143Nd/144Nd and 176Hf/177Hf (0.5130 and 0.2831 respectively). These samples represent the depleted (asthenospheric) mantle and are situated towards the front of the arc in east Java. It is likely that the progressive enrichment further back on the arc (i.e. Leucititic compositions at Ringgit-Besar) include more of an enriched (lithospheric) mantle (SCLM) component derived from the NW margin of Australia during the breakup of Gondwana

    Intercellular Bridges in Vertebrate Gastrulation

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    The developing zebrafish embryo has been the subject of many studies of regional patterning, stereotypical cell movements and changes in cell shape. To better study the morphological features of cells during gastrulation, we generated mosaic embryos expressing membrane attached Dendra2 to highlight cellular boundaries. We find that intercellular bridges join a significant fraction of epiblast cells in the zebrafish embryo, reaching several cell diameters in length and spanning across different regions of the developing embryos. These intercellular bridges are distinct from the cellular protrusions previously reported as extending from hypoblast cells (1–2 cellular diameters in length) or epiblast cells (which were shorter). Most of the intercellular bridges were formed at pre-gastrula stages by the daughters of a dividing cell maintaining a membrane tether as they move apart after mitosis. These intercellular bridges persist during gastrulation and can mediate the transfer of proteins between distant cells. These findings reveal a surprising feature of the cellular landscape in zebrafish embryos and open new possibilities for cell-cell communication during gastrulation, with implications for modeling, cellular mechanics, and morphogenetic signaling

    Historia Successorum Regum Britanniae: A Study in Medieval and Early Modern English Historico-Legal Argument

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    This thesis is a longue-duree intellectual history that takes as its subject a form of historico-legal argument, which, for the sake of analytical convenience, will be termed the 'succession claim'. Employing the serial contextualist method pioneered by David Armitage, the dissertation constructs a transtemporal narrative that ranges across some three-and-a-half centuries in order to trace the trajectory of a single intellectual tradition through time. It seeks to prove that numerous periods of English history which are usually considered discrete and are ordinarily analysed synchronically were in fact linked by a common diachronic context. The succession claim was a form of English historico-legal argument invented at the turn of the thirteenth century. It was predicated on the idea that the kings of England were the juristic successors to the kings of Britain, and, as such, were entitled to preserve or recover -- as the case may be -- the rights and lands which had once been enjoyed by their eminent predecessors. In other words, the succession claim assumed that the various forms of regalian property which had been accumulated (and subsequently lost) between the reign of the first British monarch, Brutus, and that of the last, Cadualadrus, belonged de jure -- if not de facto -- to the kings of England. According to this logic, if certain British rulers had once enjoyed overlordship of the island then it followed that the English were subsequently entitled to recover these territories at their pleasure. Likewise, if certain British rulers had once wielded caesaropapal power then it followed that their English successors were entitled to restore this authority at will. It did not matter that the English were not the British, nor that decades, centuries, and even millennia might have passed since such rights or lands had last been possessed. The succession claim consisted of two key elements. Its historical component was grounded in the English appropriation of Geoffrey of Monmouth's Historia Regum Britanniae (c. 1138). Initially suspicious of the Historia for political and historiographical reasons, the English began incorporating Geoffrey's legendary epic into accounts of their own history from the late twelfth century. The constitutional component of the succession claim presupposed the inalienability of regalian property. It assumed that that which belonged to the realm -- as opposed to the king in his private capacity -- could never truly be lost. Even those rights and lands which had been forfeited in the conventional sense of the term were said to remain the kingdom's on a de jure basis. A potent and highly versatile form of historico-legal argument, the succession claim was episodically deployed throughout the medieval and early modern periods in support of a wide range of political programmes. The English thinkers who used it did so, almost invariably, in order to portray revolutionary goals as attempts either to conserve the status quo or to restore the status quo ante. This thesis does not purport to document every instance in which identifiable historical agents utilised the succession claim; it is intended to be a selective -- though representative -- account of the intellectual tradition. The dissertation reconstructs four synchronic "moments" -- two from the medieval period and two from the early modern -- against the backdrop of the diachronic succession claim. Looking in particular at baronial resistance to John's kingship, Edward I's overlordship of Scotland, Henry VIII's break with the Roman Church, and Lord Protector Somerset's campaign for Anglo-Scottish union, the thesis demonstrates that historical actors from each of these periods were engaged in a transtemporal dialogue with one another, a dialogue which was made possible in large part by England's sophisticated record-keeping practices

    Intragranular Nanocomposite Powders As Building Blocks For Ceramic Nanocomposites

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    A powder-based bottom-up processing scheme is introduced for the production of ceramic nanocomposites. Internal displacement reactions between solid solution powders and metallic reactants proceeding via gaseous intermediates are utilized to generate nanostructured building blocks for the synthesis of ceramic nanocomposites. Subsequent rapid sintering results in ceramic nanocomposites, whose microstructures are inherited from the building blocks. This processing scheme is demonstrated for the production of titanium carbide nanocomposites featuring up to 28 wt.% intragranular tungsten inclusions derived from titanium-tungsten mixed carbide powders. Heat treatment of mixed carbide powders in evacuated ampoules containing titanium sponge and iodine at 1000°C for 24 h resulted in nanocomposite powders featuring tungsten precipitates within titanium carbide grains that were subsequently consolidated via spark plasma sintering at 1300°C for 10 min to produce titanium carbide/metallic tungsten nanocomposites. Transformation of mixed titanium–tungsten carbide powders to titanium carbide/metallic tungsten nanocomposite powders was analyzed via X-ray diffraction. Electron microscopy observations of microstructures pre- and post- sintering showed that the intragranular character of nanocomposite powders can be retained in sintered ceramic nanocomposites. The building block approach demonstrated in this work represents an improved method to make ceramic nanocomposites with majority intragranular character

    Apparent oxygen utilization rates calculated from tritium and helium-3 profiles at the Bermuda Atlantic Time-series Study site

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    © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeosciences 9 (2012): 1969-1983, doi:10.5194/bg-9-1969-2012.We present three years of Apparent Oxygen Utilization Rates (AOUR) estimated from oxygen and tracer data collected over the ocean thermocline at monthly resolution between 2003 and 2006 at the Bermuda Atlantic Time-series Study (BATS) site. We estimate water ages by calculating a transit time distribution from tritium and helium-3 data. The vertically integrated AOUR over the upper 500 m, which is a regional estimate of export, during the three years is 3.1 ± 0.5 mol O2 m−2 yr−1. This is comparable to previous AOUR-based estimates of export production at the BATS site but is several times larger than export estimates derived from sediment traps or 234Th fluxes. We compare AOUR determined in this study to AOUR measured in the 1980s and show AOUR is significantly greater today than decades earlier because of changes in AOU, rather than changes in ventilation rates. The changes in AOU are likely a methodological artefact associated with problems with early oxygen measurements.Support from this work came from the National Science Foundation (OCE-0221247, OCE-0623034, and OCE-1029676) and from the WHOI Penzance Endowed Fund in Support of Assistant Scientists

    Expectations and changing attitudes of bar workers before and after the implementation of smoke-free legislation in Scotland

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    BACKGROUND: In Scotland on March 26, 2006 a comprehensive prohibition on smoking in all enclosed public places was introduced. This study examines bar workers' attitudes towards a smoke-free working environment. METHODS: An intervention study comparing bar workers' opinions before and after the implementation of the smoke-free legislation. Bars were randomly selected in three Scottish cities (Glasgow, Edinburgh & Aberdeen) and towns (Aberdeenshire & Borders). Bar workers were recruited from 72 bars that agreed to participate from 159 approached. Pre- and post-implementation attitudes towards legislation, second-hand smoke and smoke-free working environments were compared. RESULTS: Initially the majority of bar workers agreed with the proposed legislation on smoking (69%) and the need for it to protect the health of workers (80%), although almost half (49%) thought the legislation would damage business. In 266 bar workers seen at both surveys, a significant positive attitudinal change towards the legislation was seen. Post-implementation, support for the legislation rose to 79%, bar workers continued to believe it was needed to protect health (81%) and concerns about the impact on business were expressed by fewer than 20%. Only the statement that the legislation would encourage smokers to quit showed reduced support, from 70% pre-implementation to fewer than 60% post-implementation. Initial acceptance was greater among younger bar workers; older workers, initially more sceptical, became less so with experience of the legislation's effects. CONCLUSION: This study shows that bar workers had generally positive attitudes towards the legislation prior to implementation, which became stronger after implementation. The affirmative attitudes of these key stakeholders are likely to contribute towards the creation of 'smoke-free' as the new social norm

    Patient experience of care in a student-faculty collaborative practice

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    Student Run Clinics (SRCs) are a popular means of caring for the underserved while providing valuable medical education opportunities. Reports of patient experience surveys are rare in this setting. This is troublesome because it is possible that underserved patients, who are more likely to receive care at SRCs, are not receiving the same level of care as at more traditional medical practices. The purpose of this research was to measure patient experience in a student-led medical clinic. The method included the use of patient experience surveys, which were self-administered pre-visit and self- and interviewer administered post-visit. The key results, 100% of patients felt treated with respect. 81.4% of patients would “definitely” and 16.3% would “somewhat” refer their family and friends to the clinic. 87% reported being seen within 15 minutes of their appointment time; 60% reported that they knew they would be seen by medical students and a doctor. This data has been useful to our student-led clinic in streamlining clinic flow, reducing wait times and building awareness of our structure. Our hope is this study will encourage others SRCs to adopt similar student-faculty collaborative research based practices to enhance care for SRC patients while teaching students to use patient feedback to improve quality of care

    A new era of wide-field submillimetre imaging: on-sky performance of SCUBA-2

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    SCUBA-2 is the largest submillimetre wide-field bolometric camera ever built. This 43 square arc-minute field-of-view instrument operates at two wavelengths (850 and 450 microns) and has been installed on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. SCUBA-2 has been successfully commissioned and operational for general science since October 2011. This paper presents an overview of the on-sky performance of the instrument during and since commissioning in mid-2011. The on-sky noise characteristics and NEPs of the 450 and 850 micron arrays, with average yields of approximately 3400 bolometers at each wavelength, will be shown. The observing modes of the instrument and the on-sky calibration techniques are described. The culmination of these efforts has resulted in a scientifically powerful mapping camera with sensitivities that allow a square degree of sky to be mapped to 10 mJy/beam rms at 850 micron in 2 hours and 60 mJy/beam rms at 450 micron in 5 hours in the best weather.Comment: 18 pages, 15 figures.SPIE Conference series 8452, Millimetre, Submillimetre and Far-infrared Detectors and Instrumentation for Astronomy VI 201

    Dopaminergic systems create reward seeking despite adverse consequences

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    Resource-seeking behaviours are ordinarily constrained by physiological needs and threats of danger, and the loss of these controls is associated with pathological reward seeking1. Although dysfunction of the dopaminergic valuation system of the brain is known to contribute towards unconstrained reward seeking2,3, the underlying reasons for this behaviour are unclear. Here we describe dopaminergic neural mechanisms that produce reward seeking despite adverse consequences in Drosophila melanogaster. Odours paired with optogenetic activation of a defined subset of reward-encoding dopaminergic neurons become cues that starved flies seek while neglecting food and enduring electric shock punishment. Unconstrained seeking of reward is not observed after learning with sugar or synthetic engagement of other dopaminergic neuron populations. Antagonism between reward-encoding and punishment-encoding dopaminergic neurons accounts for the perseverance of reward seeking despite punishment, whereas synthetic engagement of the reward-encoding dopaminergic neurons also impairs the ordinary need-dependent dopaminergic valuation of available food. Connectome analyses reveal that the population of reward-encoding dopaminergic neurons receives highly heterogeneous input, consistent with parallel representation of diverse rewards, and recordings demonstrate state-specific gating and satiety-related signals. We propose that a similar dopaminergic valuation system dysfunction is likely to contribute to maladaptive seeking of rewards by mammals
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