Zugl.: Bratislava, Univ., Diss., 2004

This thesis concerns the viability of the 'Yin-Yang grid' for future generations of atmospheric models. The 'Yin-Yang grid’, is an overset grid in which two segments of the classical latitude-longitude grid, with the poles excised, are rotated relative to each other and fit together rather like the surface of a tennis ball. We investigate whether wave propagation can be accurately modelled across the overlap regions and whether transport of air mass properties, such as entropy or water content, can be modelled accurately and conservatively across the overlap regions, without significant 'grid imprinting' on the solution. The wave propagation results demonstrate that the overlapping regions support computational/spurious wave modes and methods for controlling these wave modes are discussed. Transport schemes are investigated in one dimension using the Chesshire and Henshaw conservative interpolation scheme [Chesshire and Henshaw 1984] and the new 'Zerroukat mass fixer' scheme. The Zerroukat mass fixer scheme is extended to the (two-dimensional) Yin-Yang grid. The results demonstrate that the Zerroukat mass fixer scheme is successful in conserving mass. However, the Zerroukat scheme has an effect on flux limiter schemes, overshoots can occur. The Zerroukat scheme also reduces convergence rates by 2 orders of accuracy. Therefore if 2nd order convergence is required a 4th order scheme would need to be used.

Thesis (Th. M.)--Western Seminary, Portland, OR, 2003. / Abstract. Includes bibliographical references (leaves 171-185).

There is no abstract available for this thesis.

Thesis--Guo li Taiwan da xue zhong wen yan jiu suo. / On double leaves. Bibliography: p. 157-167.

Thesis (Th. M.)--Western Seminary, Portland, OR, 2003. / Abstract. Includes bibliographical references (leaves 171-185).

Thesis (Th. M.)--Western Seminary, Portland, OR, 2003. / Abstract. Includes bibliographical references (leaves 171-185).

This research aims to suggest a means of creating a closer relationship between technological artwork and its viewers through applying 'naturalising' technology in art using the theory of Yin-Yang O-Hang. The questions are raised : 1/. What are the vital factors of technological artworks? 2/. What sorts of methods can make using technology in arts more effective? 3/. How to overcome the difficulties in getting an intimate relationship between viewers and technological artworks? In order to optimise the aesthetic use of technology in art, the research is thus focused on 'naturalising' technology as a possible solution to overcome the negative aspects of technological artworks through the application of the theory of Yin-Yang O-Hang.Throughout this research, the author has discussed the fundamental concerns of the theory and its applications in Western and Eastern art. Furthermore, in investigating a number of artworks, the trends have been explored in technological art which are compatible with nature and humanity. The author has tried to find a way of applying the theory of Yin-Yang O-Hang to make technological art more intimate and accessible to viewers / Master of Arts (Hons)

Thesis (M.A.P.S.)--Associated Mennonite Biblical Seminaries, 1983. / Includes bibliographical references (leaves [74]-77).

Em mamíferos, a espermatogênese é mantida pela autorrenovação e diferenciação das células-tronco espermatogoniais (SSC). Apesar da grande importância do SSC para a fertilidade masculina, em Bos taurus pouco se sabe sobre a sua identificação e biologia celular. Para roedores, mais de 30 marcadores para células germinativas indiferenciadas já foram descritos. No entanto, ainda não é conhecido um marcador específico apenas para SSC. Quase todos são também expressos por gonócitos, espermatogônias mais diferenciadas ou mesmo células somáticas. Yin Yang 2 (YY2) é um factor de transcrição expresso nas células com a morfologia de gonócitos e SSC, sendo um candidato a marcador de SSC. Assim, a identificação de novos marcadores para SSC e factores que afectam a sua expressão, tais como a idade, são fundamentais para o desenvolvimento da biotecnologia como transgenia e tratamento de infertilidade, nos quais as SSC poderiam ser ferramentas biológicos importantes. Assim, nesta tese temos duas hipóteses principais: 1) a idade do dador afeta a expressão de marcadores moleculares específicos de SSC bovinas assim como potencial de células-tronco dessas células e que as sequências de DNA em que se associa YY2 regulam a expressão génica de SSC em camundongos. Os objetivos específicos, organizados em 4 artigos científicos, foram: identificar a melhor plaqueamento diferencial para enriquecer SSC bovina (artigo 1), verificar se a expressão de marcadores moleculares de SSC bovina difere entre adultos pré-púberes (artigo 2 e 3), identificar novos marcadores específicos para SSC em Bos taurus (artigo 3), verificar que a idade afeta o potencial de célula-tronco de SSC bovinas (artigo 3), descrever YY2 como um marcador específico para SSC em camundongos e verificar se as sequências DNA associadas YY2 são loci de importância para SSC. Assim, definimos o melhor plaqueamento diferencial para o enriquecimento de SSC bovinas, que idade afeta a expressão marcadores já estabelecidos assim como genes específicos do transcriptoma de SSC bovinas e que idade também afeta o seu potencial de células-tronco (ensaio de repopulação). Concluímos também que YY2 é um marcador para SSC de camundongo em cultivo, em animais adultos e que as sequências do genoma que se associam YY2 possivelmente tem capacidade de regulação génica em SSC murina. / Mammalian spermatogenesis is sustained by self-renewal and differentiation of spermatogonial stem cells (SSC). Despite the importance of the SSC for male fertility, in Bos taurus líttle is known about their identification identity and cell biology. For rodents, more than thirty markers for undifferentiated germ cells have already been described. However, none of these represents a marker specific for SSC, as most are also expressed in gonocytes, differentiated spermatogonia or even somatic cells. Yin Yang 2 (YY2) is a transcription factor specifically expressed in cells with the morphology of gonocytes and SSC in the mouse, being a candidate marker for SSC. For the use of SSC as an important biological tool in the development of biotechnology such as transgenesis and the treatment of infertility, it is important to identify new markers for SSC and factors that affect their expression, such as the age of donors. Therefore, the experimental work described in this thesis was based on two main hypothesis: (1) the donor age affects the expression of specific molecular markers in SSC as well their potential as stem cells and 2) YY2 exerts important functions in SSC and genomic targets correspond to loci relevant for gene regulation or genome management in SSC. The specific goals have been organized in 4 manuscripts as follows: optimization of differential plating to enrich for bovine SSC (Article 1), check if the expression of molecular markers of bovine SSCs differs between prepubertal and adult donors (Article 2 and 3), identify new markers specific for SSC in Bos taurus (Article 3), continuation of the initial description of YY2 as a specific marker for SSC in mice and check if sequences bound by YY2 in vivo harbor the capacity to influence gene expression in SSC. As conclusions, we present an optimized differential plating protocol for the enrichment of bovine SSC, we conclude that age effects the expression of SSC markers, the expression of specific genes of bovine SSC and that age also affects their potential as stem cells (measured in repopulation assays). We also contribute to the description of the restricted expression of YY2 in prepuberal and adult SSC in mice and we show that YY2 binding sites represent genomic sequences relevant for control of gene expression.