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La inhibición en la actividad de ciertas enzimas esenciales puede generar disturbios en la fisiología de algunos organismos como insectos, plantas y microorganismos y en muchos casos puede conducir a su muerte. Por otro lado, la inhibición de estas proteínas logra modificar factores implicados en la manifestación de determinadas enfermedades. Entre las enzimas que muestran estas características podemos mencionar a tirosinasa, p-hidroxifenilpiruvato dioxigenasa (HPPD) y acetilcolinesterasa (AChE). Debido a la necesidad de nuevas drogas con acción inhibidora de las mencionadas enzimas,los investigadores están explorando el mundo vegetal con el fin de obtenerlas,ya que se ha comprobado que las plantas son capaces de sintetizar esta clase de moléculas. Plantas nativas de nuestra región presentan esta propiedad. Continuando con la búsqueda de compuestos bioactivos obtenidos de plantas, se propone en este proyecto obtener nuevos agentes naturales altamente efectivos en inhibir las nombradas enzimas a partir de 100 plantas nativas de la región central de Argentina. Los compuestos aislados pueden ser utilizados directamente o servir como modelo para la síntesis de análogos. En primer lugar se determinará la efectividad de los extractos obtenidos a partir de las plantas seleccionadas como inhibidores de HPPD (utilizando el método del enol-borato) con el fin de seleccionar el más potente. A partir de este extracto y de aquellos seleccionados como más potentes en inhibir tirosinasa y AChE se aislarán, mediante aislamiento bioguiado, e identificarán el/los compuesto/s responsables. Este proceso será llevado a cabo por técnicas cromatográficas y espectroscópicas y el seguimiento de actividad se realizará mediante el método de enol-borato, dopacromo y Ellman para HPPD, tirosinasa y AChE,respectivamente. Posterior a determinar el nivel de actividad (IC50) de cada compuesto aislado se estudiará el posible efecto sinergista que pudieran ejercer al combinarlos entre ellos (si más de un compuesto es aislado de una planta) y con compuestos comerciales. Si los resultados muestran que los extractos ensayados y los metabolitos activos presentes en ellos exhiben alta efectividad en inhibir las enzimas, ellos pueden surgir como agentes terapéuticos eficaces para el tratamiento de ciertas enfermedades que las involucran y de esta manera mejorar la calidad de vida de los pacientes afectados. Estos productos pueden dar lugar a las compañías farmaceúticas a producir drogas no convencionales como nuevas alternativas medicinales. Por otro lado estas sustancias pueden derivar en novedosos herbicidas, antimicrobianos o insecticidas.Dado que todas las plantas propuestas crecen fácilmente en Argentina, la producción de estos medicamentos significaría nuevas fuentes laborales para nuestro país. El hecho de poder obtener y posteriormente utilizar estos productos aumenta en forma sustancial el aprovechamiento que podemos darle a nuestra rica flora nativa.
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This research uses the textile/text axis concept as a conceptual tool to investigate the role of textile and text in contemporary women’s art practice and theorizing, investigating textile as a largely hitherto unacknowledged element in women’s art practice of the late 20th and early 21st centuries. Textile and text share a common etymological root, from the Latin textere to weave, textus a fabric. The thesis illuminates the pathways whereby textile and text played an important role in women reclaiming a speaking voice as creators of culture and signification during a revolutionary period of renewal in women’s cultural contribution and positioning. The methodological approach used in the research consisted of a comprehensive literature review, the compilation of an inventory of relevant women artists, developing a classificatory system differentiating types of approaches, concerns and concepts underpinning women’s art practice vis a vis the textile/text axis and a series of three in-depth case studies of artists Tracey Emin, Louise Bourgeois and Faith Ringgold. The thesis points to the fact that contemporary women artists and theorists have rounded their art practice and aesthetic discourse in textile as prime visual metaphor and signifier, turning towards the ancient language of textile not merely to reclaim a speaking voice but to occupy a ground breaking locus of signification and representation in contemporary culture. The textile/text axis facilitated women artists in powerfully countering a culturally inscribed status of Lacanian ‘no-woman’ (a position of abjection, absence and lack in the phallocentric symbolic). Turning towards a language of aeons, textile as fertile wellspring, the thesis identifies the methodologies and strategies whereby women artists have inserted their webs of subjectivities and deepest concerns into the records and discourses of contemporary culture. Presenting an anatomy of the textile/text axis, the thesis identifies nine component elements manifesting in contemporary women’s aesthetic practice and discourse. In this cultural renaissance, the textile/text axis, the thesis suggests, served as a complex lexicon, a system of labyrinthine references and signification, a site of layered meanings and ambiguities, a body proxy and a corporeal cartography, facilitating a revolution in women’s aesthetic praxis.
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This thesis describes a search for very high energy (VHE) gamma-ray emission from the starburst galaxy IC 342. The analysis was based on data from the 2003 — 2004 observing season recorded using the Whipple 10-metre imaging atmospheric Cherenkov telescope located on Mount Hopkins in southern Arizona. IC 342 may be classed as a non-blazar type galaxy and to date only a few such galaxies (M 87, Cen A, M 82 and NGC 253) have been detected as VHE gamma-ray sources. Analysis of approximately 24 hours of good quality IC 342 data, consisting entirely of ON/OFF observations, was carried out using a number of methods (standard Supercuts, optimised Supercuts, scaled optimised Supercuts and the multivariate kernel analysis technique). No evidence for TeV gamma-ray emission from IC 342 was found. The significance was 0.6 a with a nominal rate of 0.04 ± 0.06 gamma rays per minute. The flux upper limit above 600 GeV (at 99.9 % confidence) was determined to be 5.5 x 10-8 m-2 s-1, corresponding to 8 % of the Crab Nebula flux in the same energy range.
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Machine learning, inductive logic programming, search
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Gastrointestinal cancers, HCC, ectopeptidases, differential display, gasdermin-like
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Magdeburg, Univ., Fak. für Informatik, Diss., 2012
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Magdeburg, Univ., Fak. für Informatik, Diss., 2015
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We provide some guidelines for deriving new projective hash families of cryptographic interest. Our main building blocks are so called group action systems; we explore what properties of this mathematical primitives may lead to the construction of cryptographically useful projective hash families. We point out different directions towards new constructions, deviating from known proposals arising from Cramer and Shoup's seminal work.
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We accomplish two goals. First, we provide a non-cooperative foundation for the use of the Nash bargaining solution in search markets. This finding should help to close the rift between the search and the matching-and-bargaining literature. Second, we establish that the diversity of quality offered (at an increasing price-quality ratio) in a decentralized market is an equilibrium phenomenon - even in the limit as search frictions disappear.
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We study pair-wise decentralized trade in dynamic markets with homogeneous, non-atomic, buyers and sellers that wish to exchange one unit. Pairs of traders are randomly matched and bargaining a price under rules that offer the freedom to quit the match at any time. Market equilbria, prices and trades over time, are characterized. The asymptotic behavior of prices and trades as frictions (search costs and impatience) vanish, and the conditions for (non) convergence to walrasian prices are explored. As a side product of independent interest, we present a self-contained theory of non-cooperative bargaining with two-sided, time-varying, outside options.