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Untersuchungen zur Prävalenz von Rotaviren der Gruppe A bei Katzen und Hunden mit Durchfall sowie zur antiviralen Wirksamkeit von rekombinantem felinen Interferon OmegaNeumann, Stefanie 18 September 2012 (has links)
In der Veterinärmedizin verursachen Rotaviren als Jungtiererkrankung vor allem in der Nutztierpraxis hohe ökonomische Verluste. Über die Prävalenz von Rotavirusinfektionen bei Hunden und Katzen ist sehr wenig bekannt, obwohl von den in der Literatur als wechselseitig zwischen Mensch und Tier übertragbaren Viren ein nicht zu unterschätzendes Risiko ausgehen kann. Zunächst wurden retrospektiv Prävalenzdaten über den Nachweis von Rotaviren bei Hunden und Katzen mit Durchfall im Vergleich zu Coronaviren und Parvoviren erhoben. Dazu wurden Kotproben von 2055 Hunden und 1481 Katzen quantitativ auf das Vorhandensein von Rota-, Corona- und Parvovirus untersucht. Desweiteren wurden Aspekte der geographischen Verteilung, der Altersverteilung, mögliche Rasseprädispositionen und das Auftreten saisonaler Erkrankungsgipfel untersucht und ausgewertet. Für Rotavirusinfektionen beträgt die statistische Prävalenz 7% bei Hunden und 8% bei Katzen. Bei Hunden und Katzen konnten signifikant häufiger Dreifachinfektionen nachgewiesen werden. Bei einer Infektion mit Rota- und Coronavirus liegt beim Hund zu 100% auch eine Infektion mit Parvovirus vor. Zweifachinfektionen kamen weniger häufig vor als Monoinfektionen. Alle drei Virusinfektionen kamen bei Hunden statistisch signifikant häufiger in der Altersgruppe ≤ 1 Jahr vor. Ein statistisch signifikant häufiger Rotavirusnachweis konnte bei der Katzenrasse Siam nachgewiesen werden, während keine Hunderasse besonders hervortrat. Im Postleitzahlengebiet 3 konnten im Beobachtungszeitraum von 2000 bis 2006 statistisch signifikant häufiger Rotavirusinfektionen bei Hunden nachvollzogen werden. Es konnte sowohl für Hunde, als auch für Katzen der Trend belegt werden, dass bei steigenden Lufttemperaturen, die Anzahl der Rotavirusinfektionen sinkt. Es kann somit von einer bedingten Saisonalität ausgegangen werden. Im zweiten Teil der Arbeit wurde die Empfänglichkeit von Rotaviren gegenüber kommerziell erhältlichem Typ I Interferon (rFeIFN-ω) in vitro getestet. Zunächst wurde zum Nachweis der Aktivität der Typ I Interferone (rFeIFN-ω, rBoIFN-α, rHuIFN-α) die Expression des Mx Proteins auf Zelllinien felinen, caninen, bovinen und humanen Ursprungs, sowie auf Affenzelllinien untersucht. Es konnte gezeigt werden, dass rBoIFN-α ausschließlich auf Zellen bovinen Ursprungs eine konzentrationsabhängige Expression des Mx Proteins induziert. Das rFeIFN-ω induziert auf Zellen felinen und bei höheren Konzentrationen auch auf Zellen caninen Ursprungs die Expression des Mx Proteins. Das rHuIFN-α zeigt eine konzentrationsabhängige Induktion des Mx Proteins in Zellen humanen, caninen, felinen und bovinen Ursprunges, sowie in Affenzelllinien. Somit konnte in vitro eine Kreuz-Speziesspezifität für rekombinantes humanes Interferon nachgewiesen werden. Zum Nachweis einer immunmodulatorischen Wirkung wurde die Expression der MHC I Oberflächenrezeptoren nach Behandlung mit rFeIFN-ω und rHuIFN-α untersucht. Die Behandlung mit rFeIFN-ω führte ausschließlich in felinen Zellen zu einer konzentrationsabhängigen signifikanten Erhöhung der Rezeptordichte. Die Behandlung mit rHuIFN-α führte zu einer konzentrationsabhängigen signifikanten Erhöhung der Rezeptordichte auf felinen Zellen und in der Affenzelllinie MA104. Die Empfänglichkeit von Rotaviren gegenüber rFeIFN-ω wurde auf der embryonalen felinen Fibroblastenzelllinie (KE-R) und auf der embryonalen felinen Gehirnzelllinine (KG-R) unter steigender Interferonkonzentration (101-104 Einheiten/ml) untersucht. Beide Zelllinien zeigten eine deutliche Reduktion der infizierten Zellen bei steigender Interferonkonzentration. Die antivirale Wirkung war in KE-R Zellen deutlicher ausgeprägt. Dort konnten bereits bei einer Interferonkonzentration von 103 Einheiten/ml keine sichtbar infizierten Zellen mehr nachgewiesen werden, während KG-R Zellen erst bei einer Konzentration von 104 Einheiten/ml keine sichtbar infizierten Zellen mehr nachzuweisen waren. Abschließend wird deutlich, dass Infektionen mit Rotaviren ein vielmals vernachlässigtes Problem in der Veterinärmedizin darstellt, vor allem, wenn man von einer Vergesellschaftung mit den für Hund und Katze pathogenen Viren Corona- und Parvovirus ausgeht. Mit dem rFeIFN-ω steht in vitro eine wirksame antivirale Substanz gegen Rotavirusinfektionen zur Verfügung.
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Rôle des acides gras polyinsaturés essentiels dans l'infarctus du myocardeGilbert, Kim 05 1900 (has links)
No description available.
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Investigation of Meson Production at COSY-TOF Using the Analysis Framework TofRootSchulte-Wissermann, Martin 14 July 2004 (has links)
The TOF-spectrometer located at the proton accelerator COSY (Juelich) stands out for experimental versatility. This is due to its modular setup: about ten subdetectors can be be arranged to satisfy the individual requirements of specific experiments. However, this flexibility hampers the calibration and the data analysis, since for each new detector setup the software has to be adjusted as well. Therefore, a new analysis framework (TofRoot) has been developed. A set of concepts is used that enables teamwork and leads to an efficient data-analysis, even for different beamtimes. Using TofRoot, three reactions are analyzed - each for two different beam momenta (2950 MeV/c, 3200 MeV/c): Firstly, the elastic proton-proton scattering. It is used to determine the luminosity and to extract benchmark results for the detector performance. Secondly, the reaction pp->deutoron-piplus is studied. Total as well as differential cross sections are presented, which nicely fit into the word data set. Finally, the vector-meson production (omega) is investigated which is the scientific focus of this work. Here, the theoretical and experimental knowledge is presently rather scarce. However, the elementary reaction dynamics is needed as an inevitable prerequisite in many fields of physics; e.g. the short range part of the nucleon-nucleon force, the description of extremely dense matter, the strangeness content of nucleons. After a detailed description of the analysis strategies, total cross sections, angular distributions, and invariant-mass spectra are presented. Some of the findings are completely new, and all provide smaller experimental uncertainties with respect to the available word data set. Finally, the results are embedded into the existing body of data and their implication on the theoretical models is discussed. / Das TOF-Spektrometer am Protonen-Beschleunigerring COSY (Juelich) besticht durch seine experimentelle Vielseitigkeit, da der modulare Aufbau aus ca.~zehn Subdetektoren eine individuelle Anpassung an spezifische experimentelle Erfordernisse ermoeglicht. Diese Flexibilitaet erschwert jedoch die Kalibrierung und die Datenauswertung, da die Software nach jedem Umbau angepasst werden muss. Daher wurde das Analyseframework TofRoot entwickelt, welches durch einen Satz von Strategien eine effiziente und teamorientierte Auswertung ermoeglicht, sogar fuer verschiedene Strahlzeiten. Mit Hilfe von TofRoot wurden drei Reaktionskanaele analysiert, jeweils fuer zwei Strahlimpulse (2950 MeV/c, 3200 MeV/c): Zuerst die elastische Proton-Proton Streuung, welche der Luminositaetsbestimmung dient und an Hand derer die Guete des Detektorsystems und der Kalibration veranschaulicht wird. Anschliessend folgt die Reaktion pp->deuteron-piplus, bei der die extrahierten Winkelverteilungen und totalen Wirkungsquerschnitte sich widerspruchsfrei in die vorhandene Datenbasis einordnen. Schliesslich wird die Vektormesonenproduktion (omega) untersucht, die den wissenschaftlichen Fokus dieser Arbeit darstellt. In diesem Kanal ist die experimentelle Datenbasis duenn und die theoretische Beschreibung bislang unvollstaendig. Ein gutes Verstaendnis der omega-Produktionsdynamik ist aber unabdingbar fuer die theoretische Beschreibung vieler Felder moderner Physik, z.B. des kurzreichweitigen Teils der Nukleon-Nukleon-Wechselwirkung, extrem dichter Materie und des Strangenessanteils im Nukleon. Nach einer detailierten Beschreibung der Analysestrategien werden totale Wirkungsquerschnitte, Winkelverteilungen und Spektren invarianter Massen vorgestellt. Verglichen mit vorhandenen Daten sind alle Angaben mit kleineren experimentellen Unsicherheiten behaftet, und zum Teil erschliessen sie zuvor nicht zugaengliche Groessen. Abschliessend werden die Ergebnisse in die vorhandene experimentelle Datenbasis eingeordnet, und ihre Auswirkung auf theoretische Modelle wird diskutiert.
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Effects of omega-3 fatty acids on rodent models of bipolar disorder and alcoholismCase, Natalie J. 20 July 2010 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Our laboratory has previously identified the clock gene D-box Binding Protein (DBP) as a candidate gene for bipolar disorder and alcoholism using a Convergent Functional Genomics (CFG) approach. In subsequent work, we established mice with a homozygous deletion of DBP as a stress-reactive genetic animal model of bipolar disorder and co-morbid alcoholism. In the present study, we found that the omega-3 fatty acid, DHA, may have mood stabilizing capabilities in stressed DBP knockout mice, and reduces alcohol consumption in these mice as well as in the alcohol preferring (P) rats. Given their potential health benefits and their relative lack of negative side-effects, omega-3 fatty acids may become an important supplement for bipolar patients and co-morbid alcoholics, a potential that warrants continued research.
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Treatment of Hypertriglyceridemia with Omega-3 Fatty Acids: A Systematic ReviewLewis, Amanda Gloria 29 June 2004 (has links) (PDF)
Purpose: To 1) critically appraise available randomized controlled trials (RTCs) addressing the efficacy of long-chain ω-3 fatty acids as a secondary prevention agent of hypertriglyceridemia, and 2) make recommendations for clinical practice.
Data Sources: All RCTs identified from several databases from 1993-2003 were reviewed by two independent reviewers who extracted data from each study and used the previously tested Boyack and Lookinland Methodological Quality Index (MQI) to determine study quality.
Results: Ten studies reported long-chain ω-3 fatty acids to be effective in the treatment of hypertriglyceridemia. The average decrease in triglycerides (TG) was 29%, total cholesterol (TC) 11.6%, very low density lipoprotein (VLDL) 30.2%, and low-density lipoprotein (LDL) 32.5%. One study found LDLs to increase by 25%. The average increase in high-density lipoprotein (HDL) was 10%. The overall average MQI score was 36% (26%-54%). Many of the RCTs had serious shortcomings including short duration, lack of a power analysis, no intention to treat analysis, no report of blind assessment of outcome, and lack of dietary control as a confounding variable.
Conclusions/Implications: Overall study methodology was weak. Although the evidence supporting the use of long-chain ω-3 fatty acids in the secondary prevention of hypertriglyceridemia is reasonably strong, until there are larger RCTs of stronger methodological quality, it is not recommended to treat hypertriglyceridemia with ω-3 fatty acid supplementation in lieu of lipid lowering medications.
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Fatty Acids and Risk of Fracture in Postmenopausal WomenOrchard, Tonya Sue 25 July 2011 (has links)
No description available.
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[en] ANALYSIS OF EXTREME VALUES THEORY AND MONTE CARLO SIMULATION FOR THE CALCULATION OF VALUE-AT-RISK IN STOCK PORTFOLIOS / [pt] ANÁLISE DA TEORIA DOS VALORES EXTREMOS E DA SIMULAÇÃO DE MONTE CARLO PARA O CÁLCULO DO VALUE-AT-RISK EM CARTEIRAS DE INVESTIMENTOS DE ATIVOS DE RENDA VARIÁVELGUSTAVO JARDIM DE MORAIS 16 July 2018 (has links)
[pt] Após as recentes crises financeiras que se abateram sobre os mercados financeiros de todo o mundo, com mais propriedade a de 2008/2009, mas ainda a crise no Leste Europeu em Julho/2007, a moratória Russa em Outubro/1998, e, no âmbito nacional, a mudança no regime cambial brasileiro, em Janeiro/1999, as instituições financeiras incorreram em grandes perdas em cada um desses eventos e uma das principais questões levantadas acerca dos modelos financeiros diziam respeito ao gerenciamento de risco. Os diversos métodos de cálculo do Value-atrisk, bem como as simulações e cenários traçados por analistas não puderam prever sua magnitude nem tampouco evitar que a crise se agravasse. Em função disso, proponho-me à questão de estudar os sistemas de gerenciamento de risco financeiro, na medida em que este pode e deve ser aprimorado, sob pena de catástrofes financeiras ainda maiores. Embora seu conteúdo se mostre tão vasto na literatura, as metodologias para cálculo de valor em risco não são exatas e livres de falhas. Nesse contexto, coloca-se necessário o desenvolvimento e aprimoramento de ferramentas de gestão de risco que sejam capazes de auxiliar na melhor alocação dos recursos disponíveis, avaliando o nível de risco à que um investimento está exposto e sua compatibilidade com seu retorno esperado. / [en] After recent financial crisis that have hit financial markets all around the world, with more property on 2008/2009 periods, the Eastern Europe crisis in 2007, the Russian moratorium on October/1998, and with Brazilian national exchange rate regime change on January/1999, financial institutions have incurred
in large losses on each of these events and one of the main question raised about the financial models related to risk management. The Value-at-Risk management and its many forms to calculate it, as well as the simulations and scenarios predicted by analysts could not predict its magnitude or prevent crisis worsened. As a result, I intent to study the question of financial systems management, in order to improve the existing methods, under the threat that even bigger financial disasters are shall overcome. Although it s content is vast on scientific literature, the Value-at-Risk calculate is not exact and free of flaws. In this context, there is need for the development and improvement of risk management tools that are able to assist in a better asset equities allocation of resources, equalizing the risk level of an investment and it s return.
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Comparing different exchange traded funds in South Africa based on volatility and returns / Wiehan Henri PeyperPeyper, Wiehan Henri January 2014 (has links)
Increasing sophistication of exchange traded fund (ETF) indexation methods required that a comparison be drawn between various methodologies. A performance and risk evaluation of four pre-selected ETF indexation categories were conducted to establish the diversification benefits that each contain. Fundamentally weighted, equally weighted and leveraged ETFs were compared to traditional market capitalisation weighted ETFs on the basis of risk and return. While a literature review presented the theory on ETFs and the various statistical measures used for this study, the main findings were obtained empirically from a sample of South African and American ETFs. Several risk-adjusted performance measures were employed to assess the risk and return of each indexation category. Special emphasis was placed on the Omega ratio due to the unique interpretation of the return series‟ distribution characteristics. The risk of each ETF category was evaluated using the exponentially weighted moving average (EWMA), while the diversification potential was determined by means of a regression analysis based on the single index model. According to the findings, fundamentally weighted ETFs perform the best during an upward moving market when compared by standard risk-adjusted performance measures. However, the Omega ratio analysis revealed the inherent unsystematic risk of alternatively indexed ETFs and ranked market capitalisation weighted ETFs as the best performing category. Equal weighted ETFs delivered consistently poor rankings, while leveraged ETFs exhibited a high level of risk associated with the amplified returns of this category. The diversification measurement concurred with the Omega ratio analysis and highlighted the market capitalisation weighted ETFs to be the most diversified ETFs in the selection. Alternatively indexed ETFs consequently deliver higher absolute returns by incurring greater unsystematic risk, while simultaneously reducing the level of diversification in the fund. / MCom (Risk Management), North-West University, Vaal Triangle Campus, 2014
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Comparing different exchange traded funds in South Africa based on volatility and returns / Wiehan Henri PeyperPeyper, Wiehan Henri January 2014 (has links)
Increasing sophistication of exchange traded fund (ETF) indexation methods required that a comparison be drawn between various methodologies. A performance and risk evaluation of four pre-selected ETF indexation categories were conducted to establish the diversification benefits that each contain. Fundamentally weighted, equally weighted and leveraged ETFs were compared to traditional market capitalisation weighted ETFs on the basis of risk and return. While a literature review presented the theory on ETFs and the various statistical measures used for this study, the main findings were obtained empirically from a sample of South African and American ETFs. Several risk-adjusted performance measures were employed to assess the risk and return of each indexation category. Special emphasis was placed on the Omega ratio due to the unique interpretation of the return series‟ distribution characteristics. The risk of each ETF category was evaluated using the exponentially weighted moving average (EWMA), while the diversification potential was determined by means of a regression analysis based on the single index model. According to the findings, fundamentally weighted ETFs perform the best during an upward moving market when compared by standard risk-adjusted performance measures. However, the Omega ratio analysis revealed the inherent unsystematic risk of alternatively indexed ETFs and ranked market capitalisation weighted ETFs as the best performing category. Equal weighted ETFs delivered consistently poor rankings, while leveraged ETFs exhibited a high level of risk associated with the amplified returns of this category. The diversification measurement concurred with the Omega ratio analysis and highlighted the market capitalisation weighted ETFs to be the most diversified ETFs in the selection. Alternatively indexed ETFs consequently deliver higher absolute returns by incurring greater unsystematic risk, while simultaneously reducing the level of diversification in the fund. / MCom (Risk Management), North-West University, Vaal Triangle Campus, 2014
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Drowning in Data, Starving for Knowledge OMEGA Data EnvironmentCoble, Keith 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The quantity T&E data has grown in step with the increase in computing power and digital storage.
T&E data management and exploitation technologies have not kept pace with this exponential
growth. New approaches to the challenges posed by this data explosion must provide for continued
growth while providing seamless integration with the existing body of work. Object Oriented Data
Management provides the framework to handle the continued rapid growth in computer speed and
the amount of data gathered and legacy integration. The OMEGA Data Environment is one of the
first commercially available examples of this emerging class of OODM applications.
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