Thesis (Ph. D.)--University of Sydney, 1993. / Includes questionnaires. Bibliography: leaves 423-445. Also available in print form.

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2002. / Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

The thesis Witt Groups of Complex Varieties studies and compares two related cohomology theories that arise in the areas of algebraic geometry and topology: the algebraic theory of Witt groups, and real topological K-theory. Specifically, we introduce comparison maps from the Grothendieck-Witt and Witt groups of a smooth complex variety to the KO-groups of the underlying topological space and analyse their behaviour. We focus on two particularly favourable situations. Firstly, we explicitly compute the Witt groups of smooth complex curves and surfaces. Using the theory of Stiefel-Whitney classes, we obtain a satisfactory description of the comparison maps in these low-dimensional cases. Secondly, we show that the comparison maps are isomorphisms for smooth cellular varieties. This resultapplies in particular to projective homogeneous spaces. By extending knowncomputations in topology, we obtain an additive description of the Witt groups of all projective homogeneous varieties that fall within the class of hermitian symmetric spaces.

The introduction, intentional or otherwise, of plants (both cultivated plants and weeds), animals, and technologies that occurred with Spanish colonization in the Southwest had profound impacts on vegetation and landscape that are reflected in larger changes in indigenous land and resource use, culture, and identity. Archaeological palynology provides information on both the environmental and agricultural impacts of colonialism. Through the study of two sites occupied during the colonial period, in different areas, reflecting different experiences of colonized groups, the range of effects of introductions is investigated. Paa-ko, in New Mexico, was occupied in the early colonial period and was more peripheral to the colonial system than was the second site, Tumacacori, in southern Arizona, the location of a mission that was occupied into the mid-1800s.The identification of introductions, including both new plants and new ways of cultivating and processing plants, in the pollen record is central to this study. The differentiation, using pollen diameters, of grasses is particularly important, although studies of reference pollen show a great overlap between these types. Because of the importance of pollen diameters for the identification of this and other pollen types, factors that could affect pollen size, including processing methods, which did not seem to have much effect, and mounting media (and time since processing), which had rather dramatic effects on diameters, are also important. These and other experimental studies conducted to provide analogs to agricultural and processing areas that would have been seen in the Spanish colonial period, can assist in the interpretation of pollen samples from sites of this period, including the two sites discussed here. While the pollen evidence from Paa-ko demonstrates a continuation of the cultivation of native crops, including maize and squash, and the absence of cultivation of introductions, pollen from Tumacacori demonstrates the absence of cultivation of native crops, particularly maize, and, possibly, cultivation of wheat, in the area closest to the mission and most heavily influenced by missionary control, reflecting, perhaps, the greater integration of Tumacacori into the colonial system and a greater acceptance and use of introduced crops in this later colonial period.

Les Thaïs dont il est question dans cette thèse ont été détachés et cédé avec l'ancien territoire siamois de Patchan Khirikhet ou Ko Kong à la colonie française du Cambodge en 1904. En conséquence, des Thaïs sont restés dans le territoire cambodgien de Ko Kong jusqu'à présent. À plusieurs époques, toutefois, les Thaïs-Ko-Kong ont choisi de traverser la frontière afin de rentrer définitivement dans la terre patrie de Thaïlande ; l'époque des Khmers Rouges tout particulièrement a provoqué la plus grande de ces immigrations et une nouvelle dispersion des Thaïs de Ko Kong. La majorité des immigrants thaïs-Ko-Kong a trouvé refuge dans le district de Khlong Yai, dans la province frontalière de Trat. Aujourd'hui, le district thaïlandais de Khlong Yai et la province cambodgienne de Ko Kong sont ainsi l'espace transfrontalier principal des Thaïs-Ko-Kong. Cette recherche a pour le but de répondre à trois questions principales sur l'ethnogenèse des Thaïs-Ko-Kong, les identités dynamiques des Thaïs-Ko-Kong et l'hégémonie des frontières des Thaïs-Ko-Kong. Les Thaïs-Ko-Kong ne sont pas un groupe ethnique, ils sont une « ethnie-frontières », un pseudo groupe ethnique, qui s'est formé par une histoire commune liée à la délimitation des frontières et par l'expérience des immigrations depuis le Cambodge. / The Thai people studied in this research have been separated with the ancient Siamese territory of Patchan Khirikhet or Ko Kong and given to the French colony of Cambodia in 1904. Consequently, they constitute nowadays a Thai ethnic minority in Ko Kong province of Cambodia. From generation to generation, at many occasions the Thais of Ko Kong have decided to cross the borderline to go back to their ancestor's homeland. But the main immigration, the dispersion and the disappearance of many Thais from Ko Kong occurred during the Khmers Rouges period. A majority of the Thai migrants from Ko Kong province have settled down at Khlong Yai district at the extreme East of Trat province, in Thailand. At the present time, Khlong Yai district of Thailand and Ko Kong province of Cambodia are therefore a core trans-boundary area for the Thais of Ko Kong. The aims of this research are at answering three mains questions concerning the ethnogenesis, the dynamic identities of the Thais of Ko Kong and their hegemonic controls of the borderlines and border areas. The Thais of Ko Kong are not an ethnic group. They are an « border ethnic group », a pseudo-ethnic group, who have been formed by their common history of the delimitation of frontiers in 1904 and their migration experiences from Cambodia.

With increasing development in the oil and gas industry, exploration and production is continuously moving deeper off the continental shelf and onto the continental slopes. This increases the risk of submarine slope failures leading to damage of offshore structures. Thus there is a need to study and understand properties of offshore marine clays on slopes. This study was undertaken in order to understand better the characteristics of a sub-marine clay deposit taken from the Gulf of Mexico. This thesis presents the results of SHANSEP triaxial testing performed on undisturbed samples of Gulf of Mexico clay. Background information is given about the clay, the sampling program and the laboratory testing program. The GEOTAC Truepath automated stress path triaxial apparatus implemented for this research and the laboratory procedures used are described in detail. Data is summarized from the various types of tests run on the clay (CKoU compression and extension, CIU compression and extension tests, consolidations tests) and the stress history of the deposit is evaluated. The SHANSEP reconsolidation technique was used for a comprehensive program of Koconsolidated-undrained (CKoU) triaxial compression and extension tests at overconsolidation ratios (OCR) ranging from one to eight. Eighteen tests were run on jumbo piston core samples from one particular core. The consolidation phase of these SHANSEP tests provided most of the preconsolidation pressure values used to establish the stress history at the two test sites. These tests were used to estimate the in situ Ko and how it varies with OCR. The undrained shear phase of the tests provides detailed information on the values of S and m for use in the SHANSEP undrained strength equation, Su= 0vo = S(OCR)m, effective stress failure envelopes, etc.

No description available.

Os leucotrienos (LTs) são mediadores inflamatórios derivados da via 5- lipoxigenase (5-LO), com contribuição relevante na reabsorção óssea. Neste estudo investigamos o papel dos LTs na diferenciação osteogênica e o seu impacto na osteoclatogênese. Assim, foi avaliado o perfil ósseo dos camundongos 129/Sv (WT) e 5-LO Knockout (5-LO KO) por meio de microtomografia computadorizada, evidenciando maior densidade óssea vertebral e trabéculas mais espessas em machos 5-LO KO. Após isso, osteoblastos primários (OBL) foram isolados e cultivados para determinar a atividade de fosfatase alcalina (ALP) e o potencial de mineralização. Resultados mostraram que OBL KO possui maior atividade de ALP e mineralização, em todos os períodos quando comparados com WT. Em adição, o tratamento com os LTs B4 e D4 inibiu a deposição de cálcio. Os inibidores da síntese de LTs e os antagonistas do BLT1/2 foram efetivos em recuperar a formação dos nódulos mineralizados. A cinética do Alox5 apresentou um aumento da expressão nos períodos de maior diferenciação celular em OBL WT. Além disso, a expressão de OCN, MMPs 2 e 9 e RANKL foram aumentadas em células 5-LO KO em quase todos os períodos avaliados. Em geral, o estímulo com LTs, seus inibidores e antagonistas diminuiu a expressão de Sp7, Col1a1, Opg e MMP-9 e aumentou RANKL em células KO. A sinalização por meio de segundos mensageiros também foi avaliada. Células 5-LO KO apresentam menor concentração de cálcio intracelular (Ca2+i) em relação ao WT. No período de 14 dias, o estímulo com LTD4 inibiu a liberação Ca2+i independente da linhagem, em relação ao controle. Os níveis de cAMP foram menores em OBL 5- LO KO, em todos os grupos tratados ou controle. LTD4 diminuiu a concentração de cAMP, mas não LTB4, em OBL 5-LO KO. O estudo também quantificou a produção de LTB4 e outros eicosanoides em osteoblastos mostrando a sua capacidade de síntese. A análise proteômica revelou 89 proteínas com expressão diminuída em OBL 5-LO KO, de um total de 154, sendo a maioria relacionada ao citoesqueleto e ao metabolismo energético. Também foram identificadas 59 proteínas exclusivas em OBL 5-LO KO e 06 unicamente expressas em células WT, revelando as diferenças intrínsecas de cada animal. O perfil osteoclastogênico de camundongos WT vs. 5-LO KO mostrou diferenças significativas na análise fenotípica, TRAP e na expressão gênica de células derivadas da linhagem monocítica-macrofágica. Após o estímulo com M-CSF e RANKL, as células WT apresentaram osteoclastos gigantes multinucleados, porém, células 5-LO KO apresentaram uma população de células com formas e tamanhos variáveis, e menor grau de maturação. Em adição, os LTsexógenos não modularam a atividade da TRAP. O meio condicionado proveniente dos OBL WT e KO, retardaram o processo de formação dos osteoclastos. A análise da expressão gênica em osteoclastos mostrou diminuição da expressão de Alox5, Il- 1b, Il-6 e TNFa em células 5-LO KO. BLT1/2, CysLt1 e os marcadores da diferenciação Acp5, Ctsk e Nfact1 não apresentaram diferenças entre os animais. Em adição, o LTB4 diminuiu a expressão do Alox5 e a Il-1b foi aumentada em osteoclastos WT. Assim, os resultados demonstram que os LTs são capazes de modular o metabolismo ósseo, e a ausência do gene da 5-LO está relacionada ao maior perfil osteogênico. / Leukotrienes (LTs) are inflammatory mediators derived from the 5-lipoxygenase (5-LO) pathway, with a relevant contribution in bone resorption. In this study we investigated the role of LTs in osteogenic differentiation and its impact on osteoclastogenesis.Thus, the bone profile of the 129/Sv (WT) and 5-LO Knockout mice (5-LO KO) was evaluated by computerized microtomography, showing higher vertebral bone density and thicker trabeculae in 5-LO KO males. After that, primary osteoblasts (OBL) were isolated and cultured to determine alkaline phosphatase activity (ALP) and mineralization potential. Results showed that OBL KO has higher ALP activity and mineralization, in all periods when compared with WT. In addition, the treatment with LTB4 and LTD4 inhibited calcium deposition. Inhibitors of LT synthesis and BLT1/2 antagonists were effective to recover the mineralized nodules formation. The kinetics of Alox5 showed an increase in expression during cellular differentiation period in WT OBL. In addition, expression of OCN, MMPs 2 and 9 and RANKL were increased in 5- LO KO cells in almost all evaluated periods. In general, the stimulation with LTs, their inhibitors and antagonists decreased the expression of Sp7, Col1a1, Opg and MMP- 9. But it increased the RANKL expression in KO cells. The second messengers signaling was also evaluated. 5-LO KO cells showed lower concentration levels of intracellular calcium (Ca2+ i) when compared to WT cells. In the 14-day period, the LTD4 treatment inhibited the Ca2+i independent of the murine lineage, relative to the control. cAMP levels were lower in OBL 5-LO KO, in all treated or control groups. LTD4 decreased the concentration of cAMP, but not LTB4, in KO cells. The study also quantified the production of LTB4 and other eicosanoids in osteoblasts showing their ability to synthesize those metabolites. The proteomic analysis revealed 89 downregulated proteins in OBL KO, out of a total of 154, most of them related to cytoskeleton and energy metabolism. Also 59 identified proteins were unique in OBL 5-LO KO and 06 exclusively expressed in WT cells, revealing the intrinsic differences of each strain. The osteoclastogenic profile of WT vs. 5-LO KO showed significant differences in phenotypic analysis, TRAP and in the gene expression of cells derived from the monocyte-macrophage-lineage. After M-CSF and RANKL stimulation, WT cells showed multinucleated giant osteoclasts. However, 5-LO KO cells presented a population of cells with variable shapes and sizes, and a lower maturation stage. In addition, exogenous LTs did not modulate TRAP activity. The conditioned medium from OBL WT and 5-LO KO delayed the formation process of osteoclasts. Gene expression analysis in osteoclasts showed decreased expression of Alox 5, Il-1b, Il-6 and TNF in 5-LO KO cells. BLT1/2, CysLt1 and the osteoclast differentiation markers Acp5, Ctsk and Nfact1 showed no differences between the strains. In addition, LTB4 decreased the expression of Alox5, and IL-1b was increased in WT osteoclasts. Thus, the results demonstrate that the LTs are able to modulate the bone metabolism, and the absence of the 5-LO gene is related to the greater osteogenic profile.

Os mecanismos pelos quais os agentes infecciosos, independentes ou não de meio ambiente permissivo, podem promover a aterogênese e as manifestações clínicas não estão completamente esclarecidos. Apesar das numerosas publicações demonstrando a presença de antígenos ou DNA de agentes infecciosos nas placas de ateroma, a questão se o agente infeccioso pode iniciar o processo aterosclerótico ou agravá-lo permanece sem resposta, possibilitando o aprofundamento das pesquisas neste assunto. Desta forma, este trabalho tem como objetivo estudar se a infecção experimental, por C.pneumoniae e/ou M.pneumoniae, em camundongos C57BL/6 apoE KO induziria ou afetaria a intensidade e a característica de vulnerabilidade da placa ateromatosa, de acordo com o sexo e/ou a dieta rica em colesterol. Métodos: um grupo de camundongos recebeu dieta enriquecida com 1% de colesterol (hiperlipidêmica), e o outro ração com formulação adequada para espécie (normolipidêmica), desde os dois meses de idade. Aos 8 meses de idade foram subdivididos, inoculados com 106 UFI de C.pneumoniae e/ou 106 UFC de M.pneumoniae, por via intraperitoneal, reinoculados um mês após e sacrificados aos 10 meses de idade. Para análise histopatológica secções transversais das aortas torácicas foram processadas para emblocamento em parafina, cortadas com 5 µm de espessura e coradas pelas técnicas de hematoxilina-eosina e tricrômico de Masson. As medianas das variáveis: altura da placa, área da placa, área de gordura da placa, área da artéria, área da luz e porcentagem de obstrução da luz da artéria dos diferentes grupos foram submetidas ao teste de Mann Whitney, com o nível de rejeição de 5%. Resultados: a infecção por C.pneumoniae e/ou M.pneumoniae causou agravamento da aterosclerose tanto em camundongos C57BL/6 apoE KO machos quanto em fêmeas. No entanto, as fêmeas infectadas somente com M.pneumoniae evoluíram com placas mais instáveis, representadas por maior remodelamento positivo. A co-infecção por C.pneumoniae e M.pneumoniae induziu placas mais estáveis, ou seja, com menor conteúdo de gordura e sem remodelamento, tanto nos machos quanto nas fêmeas. A introdução de dieta rica em colesterol levou ao não desenvolvimento de remodelamento positivo do vaso nas fêmeas infectadas por M.pneumoniae, mas sim nas co-infectadas por C.pneumoniae e M.pneumoniae que apresentaram placas mais instáveis, por serem mais volumosas e com maior conteúdo de gordura. Nos machos houve desenvolvimento de placas mais gordurosas nos infectados por C.pneumoniae. Conclusão: A infecção por C.pneumoniae e/ou M.pneumoniae em camundongos C57BL/6 apoE KO levou ao desenvolvimento ou agravamento de placas de aterosclerose, com diferenças em relação a intensidade e padrões de vulnerabilidade de acordo com o sexo versus o tipo de agente infecciosos. Os subgrupos infectados de fêmeas apresentaram maior agravamento da aterosclerose do que os machos. A dieta rica em colesterol agravou a intensidade da aterosclerose e mudou os padrões de vulnerabilidade dos subgrupos infectados. / Independent of the presence or not a favorable ambient, mechanisms by which infectious agents may boost atherogenesis and clinical aspects are not fully elucidated. In spite of many demonstrations of infeccious agent antigens or DNA, the question if the infection may iniciate or aggravate the atherosclerotic process remains unanswered, requiring further studies. Therefore, the present work studies if the experimental infection of C57BL/6 apoE KO mice by C. pneumoniae and/or M. pneumoniae induces or affects the intensity of atherosclerosis and its characteristics of plaque vulnerability, with regard to the gender and/or the cholesterolrich diet. Methods: a group of mice was fed with 1% cholesterol-enriched diet (hyperlipidemic), from two months of age; the other group received adequately formulated food for the species (normolipidemic). At eight months of age, the mice were subgrouped according to inoculation intra-peritoneally with 106 IFU of C. pneumoniae and/or 106 CFU of M. pneumoniae, and re-inoculation one month later. They were killed at ten months of age. Cross-sectional thoracic aorta fragments were studied in embedded in paraffin block sections stained Hematoxylin-eosin and Masson?s trichromic techniques. Differences in the median of the variables: plaque height, plaque area, area of fat plaque, luminal area and percent obstruction of the lumen searched using the Mann Whitney?s test, with a 5% level of rejection. Results: the infection by C. pneumoniae and/or M. pneumoniae worsened atherosclerosis in both males and females C57BL/6 apoE KO mice. However, the M. pneumoniae inoculated female group presented more unstable plaques represented by positive remodeling of the vessel. The co-infection by both bacteria induced more stable plaque represented by low fat content and absence of vessel remodeling, in both male and female mice. The introduction of cholesterol enriched diet led to lack of positive vessel remodeling in M.pneumoniae inoculated female group, but development of unstable plaques characterized by large plaque are with high content of fat, in co-infected ones. In male groups there was development of plaque with higher fat content in the subgroup inoculated with C.pneumoniae. Conclusion: Infection by M. pneumoniae and/or C. pneumoniae, in C57BL/6 apoE KO mice, led to development or aggravation of atherosclerotic plaques, with differences regarding intensity and pattern of vulnerability according to the gender versus type of infectious agents. The infected female groups presented more aggravation of atherosclerosis than male ones. Cholesterol enriched diet aggravated the intensity of atherosclerosis and changed the patterns of vulnerability of infected subgroups.