726 research outputs found

    Historical Notes on German Press Coverage of Technology

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    Professor Kepplinger accounts for increased negativism in German media coverage of technology by pointing to changes in journalists\u27 role definitions and attitudes

    Age-related increase of kynurenic acid in human cerebrospinal fluid-IgG and beta(2)-microglobulin changes

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    Kynurenic acid (KYNA) is an endogenous metabolite in the kynurenine pathway of tryptophan degradation and is an antagonist at the glycine site of the N-methyl-D-aspartate as well as at the alpha 7 nicotinic cholinergic receptors. In the brain tissue KYNA is synthesised from L-kynurenine by kynurenine aminotransferases (KAT) I and II. A host of immune mediators influence tryptophan degradation. In the present study, the levels of KYNA in cerebrospinal fluid (CSF) and serum in a group of human subjects aged between 25 and 74 years were determined by using a high performance liquid chromatography method. In CSF and serum KAT I and II activities were investigated by radioenzymatic assay, and the levels of ÎČ2-microglobulin, a marker for cellular immune activation, were determined by ELISA. The correlations between neurochemical and biological parameters were evaluated. Two subject groups with significantly different ages, i.e. 50 years, p < 0.001, showed statistically significantly different CSF KYNA levels, i.e. 2.84 ± 0.16 fmol/ÎŒl vs. 4.09 ± 0.14 fmol/ÎŒl, p < 0.001, respectively; but this difference was not seen in serum samples. Interestingly, KYNA is synthesised in CSF principally by KAT I and not KAT II, however no relationship was found between enzyme activity and ageing. A positive relationship between CSF KYNA levels and age of subjects indicates a 95% probability of elevated CSF KYNA with ageing (R = 0.6639, p = 0.0001). KYNA levels significantly correlated with IgG and ÎČ2-microglobulin levels (R = 0.5244, p = 0.0049; R = 0.4253, p = 0.043, respectively). No correlation was found between other biological parameters in CSF or serum. In summary, a positive relationship between the CSF KYNA level and ageing was found, and the data would suggest age-dependent increase of kynurenine metabolism in the CNS. An enhancement of CSF IgG and ÎČ2-microglobulin levels would suggest an activation of the immune system during ageing. Increased KYNA metabolism may be involved in the hypofunction of the glutamatergic and/or nicotinic cholinergic neurotransmission in the ageing CNS

    Violation-mitigation-based method for PV hosting capacity quantification in low voltage grids

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    Hosting capacity knowledge is of great importance for distribution utilities to assess the amount of PV capacity possible to accommodate without troubling the operation of the grid. In this paper, a novel method to quantify the hosting capacity of low voltage grids is presented. The method starts considering a state of fully exploited building rooftop solar potential. A downward process is proposed—from the starting state with expected violations on the grid operation to a state with no violations. In this process, the installed PV capacity is progressively reduced. The reductions are made sequentially and selectively aiming to mitigate specific violations: nodes overvoltage, lines overcurrent and transformer overloading. Evaluated on real data of fourteen low voltage grids from Austria, the method proposed exhibits benefits in terms of higher hosting capacities and lower computational costs compared to stochastic methods. Furthermore, it also quantifies hosting capacity expansions achievable by overcoming the effect of the violations. The usage of a potential different from solar rooftops is also presented, demonstrating that a user-defined potential allows to quantify the hosting capacity in a more general setting with the method proposed.publishedVersionPaid open acces

    Endogenous Kynurenine Aminotransferases Inhibitor is Proposed to Act as “Glia Depressing Factor” (GDF)

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    The endogenous neuroinhibitory amino acid receptor antagonist kynurenic acid (KYNA) has been hypothetically linked to physiological processes and to the pathogenesis of several brain disorders. The aim of this study was to search KYNA metabolism i.e. KYNA levels and enzymes synthesising KYNA kynurenine aminotransferase I and II (KAT I and II) in the central nervous system (CNS) and in the peripheral nervous system. Within the investigated species we found a remarkably low KYNA content (3.4 nM) in piglet’s serum compared to rat and human serum. Furthermore, in contrast to high KAT activity present in rat and human livers, a lack of KAT I and KAT II activity was found in piglet liver and other piglet peripheral organs. Therefore we attempted to find a reason for the absence of KYNA formation in piglet peripheral tissue and we researched to find if KYNA formation in rat liver homogenate (measured under standard assay conditions for KAT activity) can be influenced by the application of piglet tissue homogenates and other body fluids. KYNA formation in rat liver homogenate was investigated in the presence of piglet liver, piglet brain, rat brain and human brain homogenates, and also in the presence of cerebrospinal fluid (CSF) of the control and of Multiple Sclerosis patients. We found a significant and dose dependent reduction of rat liver KAT I and KAT II activities in the presence of piglet brain, piglet liver, and human brain, but not in the presence of rat brain homogenate. Interestingly, CSF of the human control subjects significantly lowered rat liver KAT I activity. Furthermore, the inhibitory effect of CSF of Multiple Sclerosis (MS) patients was significantly weaker when compared to the CSF of control subjects. Our data, for the first time, indicated the presence of active component(s)—depressing factor—in the body, which was able to block KYNA formation. Reduced KAT inhibitory effect by CSF of MS patients would suggest a lowered “depressing factor” level in CSF of MS patients and is possibly responsible for an enhancement of KYNA formation and for glia activation and gliosis in the CNS. Subsequently, two fractions obtained after centrifugation of CSF from patients with Neuroborreliosis showed a significantly different ability to block KAT I activity. The CSF-sediment fraction exerts a stronger inhibitory activity than the CSF-supernatant fraction, supporting further the presence of a depressing factor. For the first time, data revealed and demonstrated the ability of endogenous components to block KYNA’s synthesis. We propose that a glia depressing factor (GDF), which is abundantly present in the body, might simultaneously control glia cell’s KAT activity, respectively KYNA synthesis and also glia proliferation. The mechanism(s) of action, the composition and structure of this factor needs to be further elaborated

    Stochastic Resonance Activity Influences Serum Tryptophan Metabolism in Healthy Human Subjects

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    Background Stochastic resonance therapy (SRT) is used for rehabilitation of patients with various neuropsychiatric diseases. An alteration in tryptophan metabolism along the kynurenine pathway has been identified in the central and peripheral nervous systems in patients with neuroinflammatory and neurodegenerative diseases and during the aging process. This study investigated the effect of SRT as an exercise activity on serum tryptophan metabolites in healthy subjects. Methods Serum L-tryptophan, L-kynurenine, kynurenic acid, and anthranilic acid levels were measured one minute before SRT and at one, 5, 15, 30, and 60 minutes after SRT. We found that SRT affected tryptophan metabolism. Serum levels of L-tryptophan, L-kynurenine, and kynurenic acid were significantly reduced for up to 60 minutes after SRT. Anthranilic acid levels were characterized by a moderate, non significant transient decrease for up to 15 minutes, followed by normalization at 60 minutes. Tryptophan metabolite ratios were moderately altered, suggesting activation of metabolism after SRT. Lowering of tryptophan would generally involve activation of tryptophan catabolism and neurotransmitter, protein, and bone biosynthesis. Lowering of kynurenic acid by SRT might be relevant for improving symptoms in patients with neuropsychiatric disorders, such as Parkinson's disease, Alzheimer's disease, schizophrenia, and depression, as well as certain pain conditions

    Polyphone Sprachkompositionen

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    Mit der vorliegenden Arbeit wird der Versuch unternommen, Elfriede Jelineks „akustische Literatur“ in einen literaturtheoretischen Kontext zu stellen, der diese Texte nicht als eine Literatur der Schrift reklamiert, sondern im Gegenteil ihre mediale Offenheit und DurchlĂ€ssigkeit kenntlich macht. Eine Fokussierung erfolgt ĂŒber die Begriffe der Partitur, der Realisierung, der Polyphonie und der medienspezifischen Dramaturgie. Als Grundlage fĂŒr die Hörspielrealisierungen liegen polyphone Multifunktionstexte vor, die aufgrund der ihnen eingeschriebenen QualitĂ€ten fĂŒr Bearbeitungen im Rundfunk aufgegriffen wurden. Diese Texte geben keine Regeln fĂŒr ihre mediale Ausformulierung vor. Von großem Interesse fĂŒr den Rundfunk waren im jĂŒngsten Zeitraum monologisch umsetzbare Texte, deren Stimmen durch technische Möglichkeiten des Mediums zum Ausdruck gebracht wurden. Im Monologhörspiel wie auch in anderen Umsetzungsformen besteht eine Herausforderung fĂŒr die Regie wie fĂŒr die Rezeption, denn das Subjekt der Schreibweise geht auf SprecherInnen und Regisseure, die Co-AutorInnen Elfriede Jelineks, ĂŒber, denen es selbst obliegt, eine Ebene der „anderen Texte“ hörbar umzusetzen, bestimmte Stimmen semantisch neu zu verketten und eigene Verbindungslinien im Text zu ziehen. Die Zahl der Möglichkeiten wird unendlich, und dies liegt in den beiden Grundparametern IntermedialitĂ€t und IntertextualitĂ€t begrĂŒndet. Durch diese laufen Jelineks Texte nicht mehr Gefahr, Teil eines hierarchischen, vom Autor bestimmten und fest vorgegebenen WerkgefĂŒges zu werden. Eine auktoriale FĂ€rbung und ein Kokettieren mit dem immer wieder aufblitzenden Autorinnen-Ich in verschiedenen Textbearbeitungen sind nicht von der Hand zu weisen, sind jedoch Teil eines Öffentlichkeits-Diskurses, der im Falle Jelineks unentwegt mitlĂ€uft. Die Personifizierung der Autorin ist ein Intertext unter vielen möglichen, der in ihr Schreiben einbezogen ist, der die Ebene des Radiophonen ebenso durchlĂ€uft wie die medial weit aktuellere Ebene des Online-Bloggings. Nichtsdestotrotz spielt auch auf diesen Ebenen die fĂŒr die Hörspiele sehr wichtige Schaffung einer medialen KĂŒnstlichkeit eine große Rolle. Schnitt, Montage, De- und Rekomposition, die Umschichtung von SprachklĂ€ngen und die Konstruktion eines Hörraums sind Mittel, um eine Entfremdung der realen, mit dem Körper verbundenen SprachĂ€ußerung zu bewirken. Die Gegebenheiten und das Potenzial des akustischen Mediums Rundfunk sind bestens geeignet, um dem „Mosaik aus Zitaten“ (Kristeva), wie es in Jelineks Texten durchaus offen zu Tage tritt, eine stimmliche oder klangliche Entsprechung auf formaler und Ă€sthetischer Ebene zu bieten und dabei kompromisslos wie die Texte selbst zu bleiben

    A simulation approach for multilocus aelection-migration models

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    Diese Diplomarbeit stellt eine Implementierung eines Software-Packets zur Simulation von Migrations-Selektionsmodellen vor. Die deterministische, diskrete Simulation iteriert die zugrunde liegende Differenzengleichung, um die Gleichgewichte des dynamischen Systems zu finden. Als Anwendungsfall wird die Gleichgewichtsstruktur einer Population unter quadratisch-stabilisierender Selektion untersucht. Zuerst wird das zugrunde liegende mathematische Modell eingefĂŒhrt und die getroffenen biologischen Annahmen erklĂ€rt. Das untersuchte dynamische System wird definiert, Fitnessfunktionen, Rekombination und Migrationsmodelle werden abgehandelt. Weiters definieren wir wichtige GrĂ¶ĂŸen, die erlauben die genetische Zusammensetzung und die Differenzierung in Gleichgewichten zu messen. Danach werden relevante Publikationen besprochen, die Simulationen vorwĂ€rts in der Zeit und quadratisch stabilisierende Selektion betreffen. Weiters wird der Grenzfall starker Migration betrachtet. Dem folgt eine detailierte Beschreibung der Implementierung. Dies umfasst das Objekt-Modell, die Datenbankarchitektur und eine Diskussion algorithmischer Belange. Schließlich werden die Resultate duch Anwendung der vorgestellten Simulation auf den Fall quadratisch stabilisierender Selektion vorgestellt. Zuerst wird der Fall einer panmiktischen Population mit zwei Allelen auf zwei Loci untersucht, wobei das Optimum der Fitnessfunktion beliebig ist. Anschließend werden zwei Deme mit symmetrisch verschobenen Optima behandelt, um Migration anhand des Deakin-Modells zu untersuchen.In this diploma thesis, the implementation of a software package is presented, which facilitates the simulation and analysis of multilocus migration-selection models. The deterministic, discrete simulation iterates the underlying difference equation to find the equilibria of the dynamical system. As an application, the equilibrium structure of a population under quadratic stabilizing selection is investigated. First, we state the biological assumptions and introduce the mathematical model. We define the investigated dynamical system and introduce fitness functions, recombination, and migration models. Furthermore, we define important quantities to measure properties of the genetic composition and of differentiation at equilibrium. Then, we review related work concerning forward-time simulations and quadratic stabilizing selection. Moreover, we discuss the limiting case of strong migration. This is followed by a discussion of the implementation of the developed software. This comprises the object model, the database architecture, and a discussion of algorithmic issues. Finally, the results obtained by the application of the program to the case of quadratic stabilizing selection are presented. First, the case of a diallelic two-locus panmictic population is investigated, allowing for arbitrary optimum position. Then, two demes are considered, displacing the optima symmetrically within the demes, and assuming the Deakin migration model

    QualitĂ€tstaxonomie fĂŒr skalierbare Algorithmen von Free Viewpoint Video Objekten

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    Diese Dissertation beabsichtigt einen Beitrag zur QualitĂ€tsbeurteilung von Algorithmen fĂŒr Bildanalyse und Bildsynthese im Anwendungskontext Videokommunikationssysteme zu leisten. In der vorliegenden Arbeit werden Möglichkeiten und Hindernisse der nutzerzentrierten Definition von subjektiver QualitĂ€tswahrnehmung in diesem speziellen Anwendungsfall untersucht. QualitĂ€tsbeurteilung von aufkommender Visualisierungs-Technologie und neuen Verfahren zur Erzeugung einer dreidimensionalen ReprĂ€sentation unter der Nutzung von Bildinformation zweier Kameras fĂŒr Videokommunikationssysteme wurde bisher noch nicht umfangreich behandelt und passende AnsĂ€tze dazu fehlen. Die Herausforderungen sind es qualitĂ€tsbeeinflussende Faktoren zu definieren, passende Maße zu formulieren, sowie die QualitĂ€tsevaluierung mit den Erstellungsalgorithmen, welche noch in Entwicklung sind, zu verbinden. Der Vorteil der Verlinkung von QualitĂ€tswahrnehmung und ServicequalitĂ€t ist die UnterstĂŒtzung der technischen Realisierungsprozesse hinsichtlich ihrer AnpassungsfĂ€higkeit (z.B. an das vom Nutzer verwendete System) und Skalierbarkeit (z.B. Beachtung eines Aufwands- oder Ressourcenlimits) unter BerĂŒcksichtigung des Endnutzers und dessen QualitĂ€tsanforderungen. Die vorliegende Arbeit beschreibt den theoretischen Hintergrund und einen Vorschlag fĂŒr eine QualitĂ€tstaxonomie als verlinkendes Modell. Diese Arbeit beinhaltet eine Beschreibung des Projektes Skalalgo3d, welches den Rahmen der Anwendung darstellt. PrĂ€sentierte Ergebnisse bestehen aus einer systematischen Definition von qualitĂ€tsbeeinflussenden Faktoren inklusive eines Forschungsrahmens und EvaluierungsaktivitĂ€ten die mehr als 350 Testteilnehmer inkludieren, sowie daraus heraus definierte QualitĂ€tsmerkmale der evaluierten QualitĂ€t der visuellen ReprĂ€sentation fĂŒr Videokommunikationsanwendungen. Ein darauf basierendes Modell um diese Ergebnisse mit den technischen Erstellungsschritten zu verlinken wird zum Schluss anhand eines formalisierten QualitĂ€tsmaßes prĂ€sentiert. Ein Flussdiagramm und ein Richtungsfeld zur grafischen AnnĂ€herung an eine differenzierbare Funktion möglicher ZusammenhĂ€nge werden daraufhin fĂŒr weitere Untersuchungen vorgeschlagen.The thesis intends to make a contribution to the quality assessment of free viewpoint video objects within the context of video communication systems. The current work analyzes opportunities and obstacles, focusing on users' subjective quality of experience in this special case. Quality estimation of emerging free viewpoint video object technology in video communication has not yet been assessed and adequate approaches are missing. The challenges are to define factors that influence quality, to formulate an adequate measure of quality, and to link the quality of experience to the technical realization within an undefined and ever-changing technical realization process. There are two advantages of interlinking the quality of experience with the quality of service: First, it can benefit the technical realization process, in order to allow adaptability (e.g., based on systems used by the end users). Second, it provides an opportunity to support scalability in a user-centered way, e.g., based on a cost or resources limitation. The thesis outlines the theoretical background and introduces a user-centered quality taxonomy in the form of an interlinking model. A description of the related project Skalalgo3d is included, which offered a framework for application. The outlined results consist of a systematic definition of factors that influence quality, including a research framework, and evaluation activities involving more than 350 participants. The thesis includes the presentation of quality features, defined by evaluations of free viewpoint video object quality, for video communication application. Based on these quality features, a model that links these results with the technical creation process, including a formalized quality measure, is presented. Based on this, a flow chart and slope field are proposed. These intend the visualization of these potential relationships and may work as a starting point for further investigations thereon and to differentiate relations in form of functions

    § 871 ABGB, res integra and Redintegration

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    Der Gesetzgeber der III. TN hat die römischrechtliche res integra-Lehre ins Irrtumsrecht des ABGB ĂŒbernommen. Seither wird im Schrifttum unter dem Schlagwort ‚Redintegration‘ das Problem erörtert, ob bzw in welchen Konstellationen die Möglichkeit besteht, ein RechtsgeschĂ€ft durch Ersatz des negativen Vertragsinteresses in den Zustand re integra zurĂŒckzuversetzen. Die Untersuchung beleuchtet diese Frage dogmengeschichtlich, und will zugleich einen Beitrag zur KlĂ€rung jener Fragen leisten, die der OGH in diesem Zusammenhang explizit offengelassen hat.The legislator of the ‚III. Teilnovelle‘ of the ABGB adopted the Roman law doctrine of res integra. Since then, the problem of whether or in which constellations it is possible to restore a contract that has entered the run-off stage to the state of ‚re integra‘ has been discussed in the literature under the catchword 'redintegration'. The work examines this question in historical terms, and aims to clarify two problems that the Austrian Supreme Court of Justice has explicitly left open in this context
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