Die Thematik der Arbeit ist in der Schuranalysis angesiedelt. Angeregt durch die Bedurfnisse von Elektrotechnik und Signalubertragungstechnik entwickelte sich dieses mathematische Gebiet, welches Matrix- und Operatorversionen von Interpolations- und Momentenproblemen behandelt. Die vorliegende Dissertation beschafgt sich mit dem "J{Potapovproblem\, einem Interpolationsproblem furFu ntionen der J{Potapovklasse, welche in einer Umgebung von Null holomorph sind. Eine nahere Untersuchung dieser Funktionenklasse zeigt, dass deren Taylorkoe zientenfolgen zur Klasse der J{Potapovfolgen gehoren. Diese Folgen sind der Ausgangspunkt fur die Konstruktion von Matrixpolynomen, mit deren Hilfe sich die Losungsmenge des J{Potapovproblems als gebrochenlineare Transformation darstellen lasst. In Kapitel 1 werden zunachst J{Potapovfolgen und J{Potapovfunktion eingefuhrt sowie das J{Potapovproblem formuliert. Dabei werden wichtige Eigenschaften und Resulate vorgestellt sowie verdeutlicht, dass das J{Potapovproblem eine Verallgemeinerung des in der Literatur ausgiebig behandelten Schurproblems ist. Daraus entsteht die Zielstellung, wohlbekannte, aus Schurfolgen gebildete, Matrixpolynome auf den J{Potapovfall zu ubertragen. Eine besondere Rolle in der Losungsmenge des J{Potapovproblems spielt die zentrale J{ Potapovfunktion, denn eine Quotientendarstellung zentraler J{Potapovfunktionen ermoglicht auch eine Analyse der allgemeinen Losung. In Kapitel 2 erfolgt die Herleitung einer solchen Darstellung sowie die Untersuchung der damit verbundenen Folgen und Matrixpolynome. Dabei werden wichtige Identitaten und Beziehungen bewiesen, welche bei der Behandlung des J{Potapovproblems eine Schlusselrolle spielen. In Kapitel 3 erfolgt eine Verallgemeinerung der Arov{Krein{Matrixpolynome des Schurproblems auf die J{Potapovklasse. Dabei wird zunachst der nichtdegenerierte Fall untersucht, bevor eine Erweiterung der Ergebnisse auf den degenerierten Fall vorgenommen wird. Ausgangspunkt fur die Untersuchungen des vierten Kapitels ist die Beobachtung, dass mit den gegebenen Daten eines J{Potapovproblems ein spezielles Stein-Tripel und damit im nichtdegenerierten Fall ein J (:= diag(J;

Ulm, Univ., Diss., 2008.

Zugl.: Augsburg, Univ., Diss., 2007.

published_or_final_version / Mathematics / Master / Master of Philosophy

Das Syndrom der polyzystischen Ovarien (PCO-Syndrom) gehört zu den häufigsten endokrinen Erkrankungen junger erwachsener Frauen. Es ist in erster Linie durch eine Hyperandrogenämie charakterisiert. Eine der wichtigsten Quellen für die weibliche Androgenproduktion ist das Nebennierenrindensteroid Dehydroepiandrosteron (DHEA). DHEA kann durch das Enzym Hydroxysteroid-Sulfotransferase (SULT2A1) insbesondere in der Leber rasch zu Dehydroepiandrosteronsulfat (DHEAS) inaktiviert werden, jedoch findet die Rückaktivierung von DHEAS zu biologisch aktivem DHEA in den meisten Geweben nur in einem vernachlässigbaren Umfang statt. Somit spielt das Enzym SULT2A1 die entscheidende Rolle in der Regulation des Verhältnisses von biologisch aktivem DHEA und inaktivem DHEAS. In dieser Arbeit wurde untersucht, ob das Verhältnis von DHEA zu DHEAS bei Patientinnen mit PCO-Syndrom gestört ist. Hierzu wurden Patientinnen mit PCO-Syndrom (n=89) und ein korrespondierendes gesundes Kollektiv untersucht. Die Serumkonzentrationen von DHEA, DHEAS und der periphere Androgenmetabolit Androstandiolglukuronid (ADG) wurden untersucht. Die mittleren Serumkonzentrationen von DHEAS und ADG unterschieden sich nicht signifikant zwischen den Patientinnen mit PCO-Syndrom und dem Kontrollkollektiv. Dagegen war die mittlere Serumkonzentration des aktiven DHEA und somit auch der DHEA/DHEAS-Quotient bei PCOS-Patientinnen gegenüber dem Kontrollkollektiv signifikant erhöht. Es konnte eine Subkohorte an PCOS-Patientinnen identifiziert werden, die knapp ein Drittel des PCOS-Gesamtkollektives ausmachte, bei denen der DHEA/DHEAS-Quotient über der 90. Perzentile des Kontrollkollektivs lag. Auch die mittlere ADG Serumkonzentration war in dieser Subkohorte gegenüber dem Kontrollkollektiv signifikant erhöht. Klinisch (BMI, Taillenumfang, Serumlipide, Blutzucker) unterschieden sich die Patientinnen der neu identifizierten Kohorte nicht von den übrigen Patientinnen. Aus den Analysen kann geschlussfolgert werden, dass eine reduzierte Aktivität des Enzyms SULT2A1 ein bedeutsamer Mechanismus in der Pathogenese des Androgenexzesses bei einem Teil der PCOS-Patientinnen sein könnte. Es bleibt zu klären, worauf die verminderte Aktivität der SULT2A1 zurückzuführen ist. / Polycystic ovary syndrome is one of the most common endocrine disorders of women in reproductive age. It is predominantly characterized by hyperandrogenemia. One of the most important sources for female androgen production is the adrenal steroid dehydroepiandrosterone (DHEA). DHEA can be rapidly inactivated to dehydroepiandrosterone sulfate (DHEAS) particularly in the liver by the enzyme hydroxysteroid-sulfotransferase (SULT2A1). Conversion from inactive DHEAS to active DHEA occurs in the most tissues to a negligible degree. The enzyme SULT2A1 plays the crucial role in the regulation of the ratio of active DHEA and inactive DHEAS. In this study we examined, if the ratio between DHEA and DHEAS is disturbed in patients with polycystic ovary syndrome. We examined patients with polycystic ovary syndrome (n=89) and a correspondent healthy cohort. We measured the serum concentrations of DHEA, DHEAS and of androstanediolglucoronide (ADG). There was no significant difference in the serum concentrations of DHEAS and ADG between both cohorts. The serum concentration of DHEA and the DHEA/DHEAS ratio was significant elevated in patients with polycystic ovary syndrome. We identified a subcohort of patients with polycystic ovary syndrome, where the DHEA/DHEAS ratio was over the 90. percentile of the control cohort. In this subcohort, the serum concentration of ADG was significant elevated. There were no clinical differences in both groups. We suggest, that a reduced activity of the enzyme SULT2A1 is responsible for the androgen excess in some of the patients with polycystic ovary syndrome. Further studies have to show, what is the cause for the reduced activity of the enzyme SULT2A1.

This thesis is an examination of the ways in which, in what Bourdieu theorises as the 'space of literary or artistic position-takings', Gertrude Stein has been continually positioned and repositioned, constructed and reconstructed: by writers in her own period, in modernism scholarship, and, particularly, by writers staking their claim as the literary avant-garde of the late 20th and early 21st Centuries.1 Since her recuperation by the Language Poets in the 1970s, and in the literary histories proposed by Marjorie Perloff and others, Stein has been positioned as the originator of an alternative avant-garde genealogy which has resisted the 'institutionalised' modernism of the New Critics. This legacy continues to the present day in claims by writers like Kenneth Goldsmith that she is a precursor for Conceptual Writing. Because they are predicated on Stein's resistance to the institution of modernism, and hinge on her removal from its history, none of these arguments discuss in any detail Stein's relationship to the historical movement which is the immediate context for her work - to the institution of modernism itself or to the institutions with which it engages. My thesis challenges the removal of Stein from her milieu by showing how her textual production must be read alongside her activity on her contemporary scene and her representation of and by other modernists. In the thesis, I re-read Stein's work as a series of explicit interventions in the institutions which form the context of the cultural production of the early 20th Century. In doing so, I consider the motivations for the reconstructions and repositionings of Stein, tracing the historiography of her presentation as an exceptional figure dislocated from her context.

Orientador: Anaglória Pontes / Resumo: Resistência Insulínica (IR) e Hiperandrogenismo (HA) na Síndrome dos Ovários Policísticos (SOP), acompanhada de Acantose Nigricans (AN), denomina-se síndrome de HAIR-AN. Tem sido relacionada com risco aumentado para diabetes mellitus e doença cardiovascular. Estudam-se agentes que melhoram a resistência insulínica na SOP. OBJETIVO: Avaliar a eficácia da metformina em mulheres obesas com síndrome de HAIR-AN. PACIENTES/MÉTODOS: 16 mulheres receberam metformina (850mg/duas vezes ao dia/seis meses). Avaliaram-se: padrão do ciclo menstrual, Índice de Massa Corpórea (IMC), Relação Cintura Quadril, Índice de Ferriman e Gallwey (IFG), acantose nigricans, Teste de Tolerância à Glicose Oral, Área Sob a Curva de Glicemia (ASCG) e Insulina (ASCI), Glicemia/Insulina, Índice de Sensibilidade à Insulina (ISI), Testosterona total e livre, Globulina Carreadora dos Hormônios Sexuais (SHBG), Índice de Androgênios Livres (IAL), Androstenediona, Sulfato de Deidroepiandrosterona, Hormônio Luteinizante/Folículo Estimulante, Prolactina, Estradiol, Estrona, Perfil lipídico e Ultra-sonografia transvaginal. RESULTADOS: Houve melhora dos ciclos menstruais, redução significativa do IMC, IFG, glicemia (jejum e 120min), ASCI, testosterona livre e colesterol total.Os níveis de testosterona total, androstenediona e IAL diminuíram significativamente aos quatro meses de tratamento mas retornaram aos valores basais com seis meses. Aumentou (p<0,05) o ISI e a relação glicemia/insulina. CONCLUSÃO: A metformina é eficaz na síndrome de HAIR-AN: reduz o peso, a resistência insulínica, melhora a intolerância à glicose, os ciclos menstruais e o hiperandrogenismo. / Abstract: Insulin Resistance (GO) and Hyperandrogenism (HA) in Polycystic Ovary Syndrome (PCOS), accompanied of Acanthosis Nigricans (A), it denominates HAIR-AN syndrome. It has been related with risk increased for diabetes mellitus and cardiovascular disease. They study agents that improve insuline resistance in PCOS. OBJECTIVE: Evaluate metformin effectiveness in obese women with HAIR-AN syndrome. PATIENTS/METHODS: 16 women received metformin (850mg/two times a day/6 months). They evaluated: menstrual cycle standard, Corporal Mass Index (CMI), Waist Hip Ratio, Ferriman's Index and Gallwey (FIG), acanthosis nigricans, Oral Glucose Tolerance Test, Area under the curves for Glycemia (ASCG) and Insulin (ASCI), Glycemia/Insulin, Insulin Sensitivity Index (ISI), Total and free Testosterone, sex hormone-binding globulin (SHBG), Free Androgens Index (FAI), Androstenedione, Deidroepiandrosterona's Sulfate, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), Prolactine, Estradiol, Estrone, lipidic profile and transvaginal Ultrasonographic. RESULTS: There was menstrual cycles improvement, significant reduction of IMC and IFG, of glycemia of fast and at 120 min, of ASCI, of free testosterone, androstenedione and total cholesterol. The levels of total testosterona, IAL decreased significantly at four treatment months but they returned to the basal values with six months. It increased (p<0,05) ISI and glycemia/insulin. CONCLUSION: Metformin is effective in HAIR-AN syndrome: it reduces the weight, the insulin resistance, improvement the intolerance to the glucose, the menstrual cycles and hyperandrogenism. / Mestre

This thesis reopens the question of subject/object relations in the works of Gertrude Stein, to argue that the fetishisms theorised by Karl Marx, Sigmund Freud, and later Walter Benjamin and Michael Taussig, and problematised by feminist critics such as Elizabeth Grosz, are central to the structure of those relations. My contribution to Stein scholarship is twofold, and is reflected in the division of my thesis into Part One and Part Two. Part One of this thesis establishes a model for reading the interconnections between subjects and objects in Stein???s work; it identifies a tension between two related yet different structures. The first is a fetishistic relation of subjects to objects, associated by Stein with materiality and nineteenth-century Europe, and the identity categories of the ???genius??? and the ???collector???. The second is a ???new??? figuration of late modernity in which the processual and tacility are central. This latter is associated by Stein with America and the twentieth century, and was a structure that she, along with other modernist artists, was developing. Further, Part One shows how these competing structures of subject/object relations hinge on Stein???s problematic formulations of self, nation, and artistic production. Part Two uses the model established in Part One to examine the detailed playing-out of the tensions and dilemmas of subject/object relations within several major Stein texts. First considered is the category of the object as it is constructed in Tender Buttons, and second the category of the subject as it is represented in the nexus of those competing structures in The Making of Americans and ???Melanctha???. The readings of Part Two engage with the major strands of Stein criticism of materiality, sexuality, and language in Tender Buttons, Stein???s famous study of objects. The critical areas engaged with in her biggest and most controversial texts respectively ??? The Making of Americans and ???Melanctha??? ??? include typology, ???genius???, and Stein???s methodologies of writing such as repetition/iteration, intersubjectivity, and ???daily living???. This thesis contends that the dilemma of subject/object relations identified and examined in detail is never resolved, indeed, its ongoing reverberations are productive up until and including her final work.

Context : The expression of androgen receptors ( AR ) in follicular granulosa cells ( GC ) of mammals suggests a role for direct AR - mediated androgen activity in the regulation of folliculogenesis, however this role and the mechanistic pathways involved have not been fully characterised. In women, excess androgen is a characteristic feature of polycystic ovary syndrome ( PCOS ), but AR - mediated activity has not been widely investigated in relation to the pathophysiology of this disorder. Hypotheses : The current thesis tested two general hypotheses related to AR activity in PCOS : 1 ) The polymorphic ( CAG ) n repeat region in the AR gene, which has functional implications for receptor activity, influences the manifestation of PCOS and 2 ) AR signalling is disrupted in GC from women with PCOS. Results : In a cross - sectional population analysis, this thesis reports an association between PCOS and long CAG repeat tracts in the AR gene, which functionally represent reduced androgen sensitivity. The association was further enhanced by compensating for the influence of X chromosome inactivation ( XCI ) on expression of specific AR alleles. Preferential expression of long CAG repeat tracts positively correlated with serum testosterone levels in PCOS patients. In an analysis of sister pairs with the same CAG repeat genotype at the AR locus, different patterns of XCI were evident when sisters had a different clinical manifestation of PCOS. Collectively, these results provide evidence that supports the hypothesis that the ( CAG ) n polymorphism in the AR influences the manifestation of PCOS, the effects of which are modulated by variable allele expression via a mechanism involving XCI. These findings accord with the concept that both genetic and environmental factors are determinants of this disorder. At the level of the ovary, AR - mediated signalling in follicular GC was influenced by proximity to the oocyte in both pigs and humans. In particular, the ability of androgen to directly induce porcine GC proliferation in vitro was dependent upon presence of the oocyte or the oocyte mitogen, growth differentiation 9 ( GDF9 ). This finding provides a potential mechanism to explain how androgens may enhance early follicle growth. Granulosa cells from women with PCOS had normal mRNA expression for AR signalling molecules, but GC surrounding the oocyte in vivo had reduced AR protein content and diminished responses to androgen in culture as compared to those from normal ovaries. GC from women with PCOS also expressed mRNA for an androgen - regulated serine protease ( hKLK3 ), which did not occur in normal GC. Therefore, follicular GC from women with PCOS have evidence of perturbed AR - mediated signalling which is likely to contribute to the pathophysiology of this disorder. As AR - mediated signalling is influenced by the oocyte, the differences in AR - mediated signalling in GC from women with PCOS may be indicative of dysregulated signals emanating from the oocyte. Conclusion : The results of this thesis indicate that abnormal AR action occurs in PCOS, but further investigation is required to determine whether this phenomenon represents a primary disruption or a secondary consequence of another primary disruption in the sequence of events that leads to aberrant folliculogenesis in this disorder. / Thesis (Ph.D.)--School of Paediatrics and Reproductive Health, 2006.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.