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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
941

Random processes in truncated and ordinary Weyl chambers: Random processes in truncated and ordinary Weylchambers

Schmid, Patrick 03 September 2011 (has links)
The work consists of two parts. In the first part which is concerned with random walks, we construct the conditional versions of a multidimensional random walk given that it does not leave the Weyl chambers of type C and of type D, respectively, in terms of a Doob h-transform. Furthermore, we prove functional limit theorems for the rescaled random walks. This is an extension of recent work by Eichelsbacher and Koenig who studied the analogous conditioning for the Weyl chamber of type A. Our proof follows recent work by Denisov and Wachtel who used martingale properties and a strong approximation of random walks by Brownian motion. Therefore, we are able to keep minimal moment assumptions. Finally, we present an alternate function that is amenable to an h-transform in the Weyl chamber of type C. In the second part which is concerned with Brownian motion, we examine the non-exit probability of a multidimensional Brownian motion from a growing truncated Weyl chamber. Different regimes are identified according to the growth speed, ranging from polynomial decay over stretched-exponential to exponential decay. Furthermore we derive associated large deviation principles for the empirical measure of the properly rescaled and transformed Brownian motion as the dimension grows to infinity. Our main tool is an explicit eigenvalue expansion for the transition probabilities before exiting the truncated Weyl chamber.
942

A study of local color in New England short stories written between 1860 and 1900 by Harriet Beacher Stowe, Rose Terry Cooke, Sarah Orne Jewett, Mary Wilkins Freeman and Alice Brown

Howard, Lois Elda. January 1938 (has links)
Call number: LD2668 .T4 1938 H63
943

Influence of waterfalls on patterns of association between trout and Natal cascade frog Hadromophryne natalensis tadpoles in two headwaterstreams of the Ukhahlamba Drakensberg Park World Heritage Site

Karssing, Jeffery Robert 06 1900 (has links)
Current literature suggests that little, if any, research has been conducted in South Africa to determine the impact of alien invasive trout on indigenous amphibian biodiversity. The primary aim of the research project was to establish whether waterfalls are seasonally important in protecting the indigenous Natal Cascade Frog Hadromophryne natalensis tadpole populations from predation by alien rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta at two sampling areas located at Injesuthi and Monk‟s Cowl Nature Reserve within the uKhahlamba Drakensberg Park World Heritage Site (UDPWHS). The dissertation argues in favour of a biotic rationale, namely trout predation, as being the primary cause for the decline of H. natalensis tadpoles below the waterfalls and systematically negates the influence of geo-physical (abiotic) environmental factors on tadpole abundance. Habitat isolation and fragmentation is identified as a latent threat to the continued persistence of H. natalensis populations in the UDPWHS. / Environmental Sciences / M. Sc. (Environmental Science)
944

Investigation of the Pre to Post Peak Strength State and Behaviour of Confined Rock Masses Using Mine Induced Microseismicity

Coulson, Adam Lee 01 March 2010 (has links)
As hard rock mining progresses into higher stress mining conditions through either late stage extraction or mining at depth, the rock mass is driven not just to the peak strength, but often well into the post-peak until complete ‘failure’ occurs and easier mining conditions become evident. Limited research has been accomplished in identifying the transition of the rock mass and its behaviour into the post-peak and this research investigates this behaviour in detail. As the rock mass progressively fails, fractures are initiated through intact rock and extension and shear failure of these and pre-existing features occurs. Associated with this failure are microseismic events, which can be used to give an indication of the strength state of the rock mass. Based on an analogy to laboratory testing of intact rock and measurement of acoustic emissions, the microseismicity can be used to identify, fracture initiation, coalescence of fractures (yield), localization (peak-strength), accumulation of damage (post-peak) and ultimate failure (residual strength) leading to aseismic behaviour. The case studies presented in this thesis provide an opportunity to examine and analyse rock mass failure into the post-peak, through the regional and confined failures at the Williams and the Golden Giant mines, both in the Hemlo camp in Northern Ontario, Canada. At the Williams mine, the progressive failure of a sill pillar region into the post-peak was analysed; relating the seismic event density, combined with numerical modelling and a spatial and temporal examination of the principal components analysis (PCA), to characterize the extent, trend and state of the yielding zone, which formed a macrofracture shear structure. Observations of conventional displacement instrumentation, indicates regional dilation or shear of the rock mass occurs at or prior to the point of ‘disassociation’ (breakdown of stable PCA trends) when approaching the residual strength. At the Golden Giant mine, the complete process from initiation to aseismic behaviour is monitored in a highly stressed and confined pendent pillar. The PCA technique, numerical modelling and focal mechanism studies are used to define significant stages of the failure process, in which a similar macrofracture structure was formed. Temporal observations of key source parameters show significant changes prior to and at the point of coalescence and localization.
945

L'Effet Hanbury Brown et Twiss pour les Atomes Froids

Schellekens, Martijn 10 May 2007 (has links) (PDF)
Cette thèse détaille la mesure des corrélations d'intensité quantiques dans des gaz d'hélium métastable. La mesure s'est opérée sur des gaz thermiques bosoniques 4He et fermioniques 3He, ainsi que sur des condensats de Bose-Einstein.<br /><br />En 1956, Robert Hanbury Brown et Richard Twiss ont mesuré la corrélation entre des photons provenant d'une même source thermique. Ils avaient ainsi mis en évidence que les photons emis par une telle source arrivaient préférentiellement groupés sur le détecteur. Ce groupement charactérise les bosons provenant d'une source non-cohérente. Les fermions manifestent un anti-groupement dans les mêmes conditions.<br /><br />En utilisant des atomes d'hélium métastables, dont l'utilisation de galettes de micro-canuax facilite la détection individuelle, nous avons pu mettre en évidence un regroupement similaire des bosons 4He provenant de sources thermiques de l'ordre du microkelvin. La cohérence des condensats de Bose-Einstein n'a pas permis de dégager une corrélation particulière, comme attendue. Une mesure sur des gaz thermiques des fermions 3He a permis de mettre en évidence leur anti-groupement. Un soin particulier a été pris pour décrire le détecteur à base de galettes de microcanaux et de lignes à retard, une des clés de la réussite de la mesure.
946

The sacramentality of the Word : through the lens of the annunciation to Mary

Genig, Joshua Dale January 2012 (has links)
This thesis seeks to demonstrate that, in failing to take the sacramentality of the Word seriously, the preaching of the Church has suffered negative consequences. In short, preaching has often become, at best, a form of instruction or, at worst, an incantation of sorts, rather than an integral part of deepening our relationship with Christ by functioning sacramentally to bring about divine participation with Jesus' corporeal humanity in his living Word. Moreover, this trouble has had a profoundly negative effect on my own Lutheran Church – Missouri Synod due, in part, to our Reformation heritage as Christians who believe, teach, and confess the sole authority and divine inspiration of Holy Scripture. Yet, what has been lost over the past 500 years since the Reformation began is the reality of Christ's ongoing corporeal presence in and for the Church, particularly as he is present in the viva vox of preaching. In order to recover that reality, I propose that one should consider the annunciation to Mary where, with a sermon of sorts, the corporeal Christ took up residence in the flesh of his hearer. In addition to granting Mary a son, however, this tangible presence of Jesus also delivered to her precisely what was contained within his own flesh: the fullness of the Godhead (Col 2:9). When understood as a biblical paradigm for the Church, it becomes clear that what happened to Mary can, indeed, happen to Christians of the present day. To that end, I propose that preaching today, when understood sacramentally, can deliver the fullness of the person of Christ, who continues to come in corporeality, with humanity and divinity, in the viva vox of preaching.
947

Potrava vydry říční (Lutra lutra) v závisloti na vysazení potoční formy pstruha obecného (Salmo trutta m. fario) a lipana podhorního (Thymallus thymallus) / Diet of Eurasian otter (Lutra lutra) in relation to the stocking of brown trout (Salmo trutta m. fario) and grayling (Thymallus thymallus)

Lyach, Roman January 2014 (has links)
This study aimed to evaluate otter predation on stocked trout and grayling. The diet composition of piscivorous Eurasian otters (Lutra lutra) was studied on the stream Chotýšanka in central Bohemia using spraint (otter faeces) analysis during one winter period (90 days). Stocking took place mostly in the second half of 2005. Around 5000 hatchery-reared brown trouts (Salmo trutta m. fario) of size about 10 cm, 600 graylings (Thymallus thymallus) of the same size and 480 rainbow trouts (Oncorhynchus mykiss) of size about 30 cm were stocked into the stream. Spraints were collected in December 2005 and January 2006. We found and identified 1531 fish in the spraints. The primary food source of otters was fish (almost 85 % of biomass). The main fish prey was small - sized, below 20 g in weight and 13 cm in length. The bulk of otter's diet consisted of less - valued species, especially the gudgeon (Gobio gobio). Other frequently consumed fish species were the European chub (Squalius cephalus), the common carp (Cyprinus carpio), the European perch (Perca fluviatilis), the brown trout and the rainbow trout. Consumption of stocked brown trout was 1,80 %, while cosumption of stocked rainbow trout was 10,90 % of biomass. Otters in this area consumed about 723 - 1446 brown trouts and 72 - 144 rainbow trouts...
948

Obraz televizního novináře v amerických televizních seriálech (od Mary Tyler Moore Show po Newsroom) / The image of television journalist in american television series (from Mary Tyler Moore Show to Newsroom)

Pavelková, Eva January 2015 (has links)
The objective of this master thesis The image of television journalist in American television series is to unveil personality traits of main characters in five selected American series during five decades (from the beginning of the 1970s to present) by means of combination of interpretative reading and semiotic (visual) analysis, and by that interpret representation of journalists. Subsequently the typologies of journalistic characters by Brian McNair and Joe Saltzman are used to categorize 27 central figures to types or stereorypes. Majority of characters combined more different types but it could be stated that all images of journalists were positive - possibly due to bigger popularity among viewers. Simultaneously it is neccesary to point out that characters across analysed series classified to same categories are not fully identical - characters show enough resemblance for type identification but similarities are outweighed by differences.
949

Beginning all over again : a metaxological natural theology of the arts

Brewer, Christopher R. January 2015 (has links)
Following Russell Re Manning, I acknowledge the diversity and persistence of natural theology. Going further than Re Manning, however, I propose a 5-type taxonomy stretching from natural theology as natural religion to natural theology as theology of nature. Having met this descriptive responsibility, I then turn in a second chapter to prescriptive possibility in dialogue with the Anglican theologian Howard E. Root (1926–2007). An early advocate of natural theology and the arts, Root called in his 1962 essay, “Beginning All Over Again,” for awareness (i.e., of the arts) rather than formal argument. Critiqued by E.L. Mascall and others, Root responded in his 1972 Bampton Lectures, “The Limits of Radicalism.” Never published, I discovered these lectures in an uncatalogued box at Lambeth Palace Library, London. Drawing upon these lectures, as well as other archival materials, I consider Root's contribution to a natural theology of the arts. That said, Root's work requires further development, and so in an effort to recover Root I have supplemented his contribution with the more recent work of David Brown, his unacknowledged theological heir. In an effort to recover Root more fully I turn in a third chapter to consider the philosopher William Desmond, the result of which is a metaxologically reformulated Root-Brown hybrid. In a fourth and final chapter, I consider the American contemporary artist Jonathan Borofsky and several others in order to see how this theoretical frame might be applied in practice as a metaxological natural theology of the arts.
950

O papel da melatonina na regulação do tecido adiposo marrom / The role of melatonin in the regulation of brown adipose tissue

Halpern, Bruno 27 August 2018 (has links)
O tecido adiposo marrom (TAM), caracterizado pela presença da proteína termogênica UCP-1, é conhecido há muitas décadas como um tecido termogênico em mamíferos, porém sua significância clínica em humanos era considerada pequena, com exceção de neonatos, até que o desenvolvimento e uso de métodos de PET-FDG terem demonstrado que humanos adultos também possuem TAM ativo, especialmente após exposição ao frio. Essa descoberta levou a um enorme aumento nas pesquisas sobre o assunto, já que sua ativação, levando a um aumento do gasto energético, poderia, pelo menos na teoria, ser uma possível arma no tratamento da obesidade e diabetes tipo 2 e sua redução ou ausência ser uma causa de ganho de peso. Muitos compostos vêm sendo estudados como possíveis recrutadores e ativdadores desse tecido. A melatonina é um deles, embora nenhum estudo tenha sido feito em humanos. A melatonina, um hormônio pineal sintetizado à noite com um papel crítico na sincronização do ritmo circadiano, é estudado há várias décadas como um regulador chave do metabolismo energético em diversas espécies animais. Ratos pinealectomizados ganham peso e tem distúrbios metabólicos durante sua vida, e a suplementação noturna de melatonina, reverte estas alterações, sem redução da ingesta alimentar. Devido a isso, uma hipótese é que o papel central da melatonina no metabolismo energético inclui sua função no gasto energético, possivelmente relacionado à ativação do TAM. Muitos modelos experimentais, a maioria em animais hibernantes, demonstraram o papel da melatonina no recrutamento do TAM. Nesse estudo, o objetivo é determinar se a suplementação de melatonina para indivíduos e animais de experimentação (ratos Wistar) deficientes de melatonina aumenta sua ativação. Foi encontrado que, em ratos Wistar, animais pinelaectomizados possuem uma capacidade termogênica do TAM reduzida após exposição ao frio comparado com a temperatura ambiente, e a suplementação de melatonina normaliza essa capacidade termogênica. Esse dado sugere um papel da melatonina na resposta máxima de ativação do TAM após um desafio ao frio agudo. Também foi observado um aumento de expressão de UCP-1 (RNA) em animais repostos com melatonina, tanto em controles como em pinealectomizados, e animais pinealectomizados não repostos apresentam uma expressão de UCP-1 menor que um grupo controle. Em humanos, a suplementação de melatonina aumenta o volume e atividade do TAM em quatro indivíduos pinealectomizados (por tumores pineais) com baixo nível de melatonina no basal, analisado por tomografia de emissão de prótons acoplada a ressonância magnética (PET-RM). Embora a análise do TAM em ambos os protocolos tenha sido distinta, seus resultados apontam para a mesma regulação positiva do TAM pela melatonina. A termografia infravermelha (TIV) foi também realizada em humanos, com aumento de atividade de TAM após exposição ao frio, poréma correlação entre as respostas com a TIV e o PET-RM foi moderada e não significativa. Diferenças entre o protocolo frio e limitação da TIV em indivíduos mais obesos podem ter contribuído para esses resultados. Uma relação positiva da suplementação de melatonina nos lípides (principalmente colesterol e triglicérides) também foi encontrada, porém sem impacto na gordura hepática / Brown adipose tissue (BAT), characterized by the presence of the thermogenic protein UCP-1 have long been known as a thermogenic tissue in mammals, however its significance in humans was considered minor, with the exception of newborns, until FDG-PET exams demonstrated that human adults still have active BAT, especially after cold exposure. This prompted to an incredible increase in research on the field, since its activation, leading to increased energy expenditure could, at least theoretically, be a possible tool for the treatment of obesity and type 2 diabetes and its reduction or absence be a cause of weight gain. Many compounds aiming to recruit and activate BAT have been studied. Melatonin has been one of them, although no study has been performed in humans. Melatonin, a pineal hormone synthetized at night with a critical role in the synchronization of circadian rhythms, has long been studied as a key regulator of energy metabolism in many animal species. Pinealectomized rats gain weight and have metabolic disturbances during life, and the circadian supplementation of melatonin, at night, reverts these alterations, without decrease in energy intake. Due to that, it is hypothesized that a main role of melatonin in energy metabolism includes its action on energy expenditure, possibly related to activation of BAT. Many experimental models, mainly in hibernating animals, have shown a role of melatonin on BAT recruitment. In the present study, we ought to determine if the supplementation of melatonin for melatonin deficient subjects and experimental animals (Wistar rats) increases BAT activation. We found, in Wistar rats, that pinealectomized animals have a reduced BAT thermogenic capacity after acute cold exposure compared with ambient temperature, and melatonin supplementation in this animals leads to normalization of BAT thermogenic capacity. This data suggests a role of melatonin in improving the maximal response of BAT after an acute challenge. We also found that melatonin supplementation increases UCP-1 RNA expression both in control and pinealectomized rats, and pinealectomized rats without supplementation have a reduced UCP-1 expression compared with controls. In humans, we found that melatonin supplementation increased BAT volume and activity in four pinealectomized (due to pineal tumors) individuals with low melatonin at baseline, analyzed by Positron Emission Tomography associated with magnetic resonance (PET-MR). Although the analysis of BAT in both studies was different, their results point to the same positive regulation of BAT by melatonin. We also performed infrared termography (IRT) in humans, but the results were not conclusive since although we also found an increase in BAT activity measured in Watts, the correlation between the methods was moderate. The difference may be due to different protocols of cold exposure between methods, probably inadequate in IRT, as well as maybe to a limitation of IRT in more obese individuals. We also found that melatonin supplementation in melatonin deficient humans may have a positive impact on blood lipid concentrations, (mainly total cholesterol and triglycerides) but, at least for the time studied, does not appear to have an impact on liver fat

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