Thesis (Ph. D.)--University of Wisconsin--Madison, 1955. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 121-123).

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Le sommet du Frasnien est une époque difficile pour la biodiversité sur la Terre, en particulier pour les organismes d’eaux chaudes et peu profondes. Cette étude vise à établir un lien entre l’activité tectonique et la crise biologique. Trois coupes d’Amérique du Nord, de la marge ouest du paléocontinent Laurentia, liées au front orogénique Antler ont été étudiées pour leurs rapports isotopiques 87Sr/86Sr dans les carbonates. La coupe de Devils Gate dans le centre Nevada (USA) présente au sommet du Frasnien des faciès de turbidites carbonatées de bassin. Trois pics successifs de 87Sr/86Sr s’observent au sommet du Frasnien, entre le deux niveaux anoxiques Kellwasser. Le dernier pic est le plus élevé, il est contemporain du début du second Kellwasser et présente un rapport isotopique de 0,7094. La coupe de North Antelope Range proche de celle de Devils Gate, présente des dépôts extrêmement homogènes et réguliers de “debris-flow” carbonatés dans un bassin d’avant-pays. Un pic du 87Sr/86Sr plus modéré y est enregistré. La coupe de Mount Cinquefoil est située dans l’Alberta (Canada), dans un contexte de rampe formant une transition entre un important complexe récifal et un bassin. A nouveau un pic de 87Sr/86Sr est enregistré au début de l’événement anoxique alors que le reste de la coupe est fort homogène. Un autre pic important du 87Sr/86Sr est présent dans la partie inférieure de la coupe à la base du premier niveau Kellwasser identifié par l’étude sédimentologique. Les différents pics du 87Sr/86Sr enregistrés dans la Zone à conodontes linguiformis sur les trois coupes présentent des points communs. D’une part ils occupent la même position par rapport à la courbe de susceptibilité magnétique enregistrée dans les trois coupes, ce qui tend à montrer qu’ils sont contemporains. D’autre part ils sont systématiquement liés à des teneurs plus fortes en éléments (Al, Ti, Si, ...) de la phase détritique dans les roches, ce qui permet d’établir un lien direct entre l’activité tectonique régionale, l’érosion continentale accentuée et les rapports isotopiques élevés du Sr. De plus ces pics du 87Sr/86Sr semblent liés à la mise en place des périodes d’anoxie des horizons Kellwasser par eutrophisation des eaux. La chemostratigraphie permet de reconnaître des phases bien distinctes de la sédimentologie détritique, en lien avec le contexte tectonique de chaque coupe. Enfin, la comparaison avec d’autres données de la littérature pose la question de la simultanéité des événements à la surface de la Terre.

The Semi-gods and the Semi-devils is one of Jin Yong¡¦s most popular Martial-arts novels. Strange adventures of the main characters: Hsiao feng, Tuan yu, Hsu-chu are analogous to those of mythic heroes. This paper uses the archetypal approach to illustrate the main characters, the heroes¡¦journeys, for archetypes are universal patterns from which myths derive. My intention is that the theory of archetypes would enable us to see the literary work differently and give fresh insights to the novel in which important elements and meanings might otherwise go unnoticed.

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Made available in DSpace on 2014-06-11T19:30:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-05-17Bitstream added on 2014-06-13T18:40:48Z : No. of bitstreams: 1 statella_t_dr_prud.pdf: 3750237 bytes, checksum: 5e7d05a021f74eef1040300825e464e5 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Dust Devils são vórtices convectivos formados por correntes de ar quente instáveis, próximas à superfície planetária. Inúmeros pesquisadores têm estudado dust devils marcianos na tentativa de melhor entender o fenômeno. Em geral, as áreas de pesquisa compreendem a simulação numérica e mecânica de dust devils em laboratório, metodologias para reconhecimento de vórtices por robôs pousados na superfície de Marte e a detecção de vórtices e rastros em imagens orbitais. A despeito do grande número de artigos relacionados ao assunto, nenhum deles aborda a detecção automática de rastros de dust devils, tarefa que ganha especial importância quando a quantidade de imagens da superfície de Marte cresce a uma taxa maior que a capacidade humana de analisá-las em um curto período de tempo. Esta Tese descreve um método inédito para detecção automática de rastros de dust devils. O banco de imagens utilizado contém 200 imagens (90 MOC e 110 HiRISE), distribuídas pelas regiões Aeolis, Noachis, Argyre, Eridania e Hellas. O método é fortemente baseado na Morfologia Matemática e usa transformações como abertura e fechamento por área morfológicos, fechamento por caminho morfológico, método de Otsu... / Dust devils are vortices caused by unstable wind convection processes near the planetary surfaces, due to solar heat. Many researchers have being studying Martian dust devils in an attempt to better understand the phenomena. Generally, the research fields comprise mechanic and numerical simulation of dust devils in laboratories, methodologies for recognition of dust devils plumes from rovers on Mars surface, detection of plumes and tracks from orbital images. Despite the number of papers regarding the subject, none of them addresses the automatic detection of dust devil tracks which is an important issue as the amount of images taken grows at a rate greater than the human capability to analyze them. This Thesis describes a novel method to detect Martian dust devil tracks automatically. The dataset comprises 200 images (90 MOC and 110 HiRISE), distributed over the regions of Aeolis, Noachis, Argyre, Eridania and Hellas. The method is strongly based on Mathematical Morphology and uses transformations such as morphological surface area closing and opening, morphological path closing and Otsu's method for automatic image binarization, among others. The method was applied to the dataset and results were compared... (Complete abstract click electronic access below)

Orientador: Erivaldo Antônio da Silva / Coorientador: Pedro Miguel Berardo Duarte Pina / Banca: Ana Lucia Bezerra Candeias / Banca: João Rodrigues Tavares Júnior / Banca: José Roberto Nogueira / Banca: Maurício Araújo Dias / Resumo: Dust Devils são vórtices convectivos formados por correntes de ar quente instáveis, próximas à superfície planetária. Inúmeros pesquisadores têm estudado dust devils marcianos na tentativa de melhor entender o fenômeno. Em geral, as áreas de pesquisa compreendem a simulação numérica e mecânica de dust devils em laboratório, metodologias para reconhecimento de vórtices por robôs pousados na superfície de Marte e a detecção de vórtices e rastros em imagens orbitais. A despeito do grande número de artigos relacionados ao assunto, nenhum deles aborda a detecção automática de rastros de dust devils, tarefa que ganha especial importância quando a quantidade de imagens da superfície de Marte cresce a uma taxa maior que a capacidade humana de analisá-las em um curto período de tempo. Esta Tese descreve um método inédito para detecção automática de rastros de dust devils. O banco de imagens utilizado contém 200 imagens (90 MOC e 110 HiRISE), distribuídas pelas regiões Aeolis, Noachis, Argyre, Eridania e Hellas. O método é fortemente baseado na Morfologia Matemática e usa transformações como abertura e fechamento por área morfológicos, fechamento por caminho morfológico, método de Otsu... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Dust devils are vortices caused by unstable wind convection processes near the planetary surfaces, due to solar heat. Many researchers have being studying Martian dust devils in an attempt to better understand the phenomena. Generally, the research fields comprise mechanic and numerical simulation of dust devils in laboratories, methodologies for recognition of dust devils plumes from rovers on Mars surface, detection of plumes and tracks from orbital images. Despite the number of papers regarding the subject, none of them addresses the automatic detection of dust devil tracks which is an important issue as the amount of images taken grows at a rate greater than the human capability to analyze them. This Thesis describes a novel method to detect Martian dust devil tracks automatically. The dataset comprises 200 images (90 MOC and 110 HiRISE), distributed over the regions of Aeolis, Noachis, Argyre, Eridania and Hellas. The method is strongly based on Mathematical Morphology and uses transformations such as morphological surface area closing and opening, morphological path closing and Otsu's method for automatic image binarization, among others. The method was applied to the dataset and results were compared... (Complete abstract click electronic access below) / Doutor

In keeping abreast of current gang phenomena, this study seeks to comparatively examine structural processes and characteristics of gangs in chronic gang city, San Antonio, and an emerging gang city that would be more likely to have "hybrid" gangs, Orlando. Hybrid gangs have been identified as having organizational processes that differ from traditional gangs; thus, this work will examine these processes that consist of a range of non-traditional phenomena, including cooperation between gangs, members switching gang affiliations, as well as gang initiations, and members leaving gangs. Additional characteristics uniquely associated with hybrid gangs consist of the notable presence of white, middle-class, and female gang members. Evidence suggests that the hybrid gang is more of a socially constructed moral panic than a reality. A limited number of recent studies have indicated that some gangs may better fit into a social network framework rather than a solid organizational analysis. Whe

Little is known about the role of microbial biofilms in nutrient cycling and ecosystem processes within desert springs. Furthermore, the difference between nutrient limitation of biofilms in desert springs and other ecosystems is unknown. Biofilms produce micro-scale physicochemical variation important to ecosystem function. We measured the variation in microscale physicochemical heterogeneity in biofilms of Devils Hole, Nevada. Microelectrodes were used to measure micro-scale chemical gradients of temperature, pH, O2, and H2S in addition to water column and pore water nutrient measurements in Spirogyra, cyanobacteria, and Beggiatoa biofilms over one year. Biofilm physicochemical gradients were used to calculate diffusion and metabolic rates. The rate of O2 and H2S diffusion ranged over two orders of magnitude. Biofilm production and respiration were influenced by biofilm type, light exposure, and sample month. Maximum O2 production occurred in spring and summer during direct light exposure. Oxygen production and consumption varied with light exposure and season. The H2S production and consumption varied with biofilm type. Higher concentrations of SO4 in Beggiatoa suggested that H2S production in Beggiatoa was quickly oxidized in the ecosystem. Spirogyra and cyanobacteria followed similar physicochemical trends; however, Spirogyra had more pronounced diurnal and seasonal variation. The differences between cyanobacteria and Spirogyra have implications on the ecosystem function of Devils Hole as well as other ecosystems with diverse biofilm communities. The heterogeneous physicochemistry of microbial biofilms and the differences in biofilm nutrient limitation suggests that a change in microbial biofilms or nutrient concentrations could alter ecosystem biogeochemical dynamics. Additionally, we assessed the nutrient limitation of two desert springs in comparison with a temperate stream. A nutrient diffusing substrata experiment was used to measure chlorophyll a, respiration, and biomass with phosphorus, nitrogen, and sulfide treatments. Autotrophic and heterotrophic biofilms responded differently to treatments and the temperate stream had higher chlorophyll a biofilm accrual but lower respiration relative to the desert springs. / Spatial and temporal variation of microbial biofilm biogeochemistry in a desert spring, Devils Hole, Nevada -- Autotrophic and heterotrophic nutrient limitation across biomes. / Department of Biology

Thesis (M.S.)--Brigham Young University. Dept. of Geological Sciences, 2008. / Includes bibliographical references.