Gut drauf durch Sport? Geschlechtsspezifisches Erleben von Körper und Gesundheit sportlich aktiver Jugendlicher

Das Untersuchungsinteresse der hier zu berichtenden Studie zielt auf die Frage, ob sich Jugendliche hinsichtlich ihrer sportlichen Aktivität in verhaltensrelevanten Aspekten ihrer subjektiven Gesundheitskonzepte unterscheiden. Vor dem Hintergrund des theoretischen Bezugsrahmens der Selbstkonzeptforschung, des aktuellen Forschungsstandes zum subjektiven Gesundheitsverständnis und zum Gesundheitsstatus werden die Daten der Jugendsportstudie NRW einer quantitativen Sekundäranalyse unterzogen: Im Zusammenhang mit der sportlichen Aktivität von Jugendlichen geht es zum einen um deren Selbsteinschätzungen von Gesundheit, zum anderen darum, auf welchem Verständnis und Erleben von Gesundheit diese Einschätzungen beruhen. Zunächst wird der Forschungsstand zur sportlichen Aktivität und zu subjektiven Gesundheitskonzepten im Jugendalter skizziert, anschließend werden zentrale Ergebnisse der eigenen Sekundärauswertung der NRW-Jugendsportstudie vorgestellt. (DIPF/Orig.

Risk-sensitive capital requirements and pro-cyclicality in lending

Risk-sensitive capital requirements aim at enforcing appropriate minimum amounts of capital to absorb losses resulting from credit defaults and other risk sources. These requirements are considered to be important as they are supposed to strengthen financial stability. Nevertheless, practitioners and scholars have worried about negative side effects arising from capital-based regulation such as the reinforcement of cyclicality in lending. These concerns are based upon the notion that regulatory rules, which become tighter in downturns, restrict the bank's total lending. As a consequence, valuable projects are not financed during recessions, which may enhance the cyclical downturns. A situation commonly known as credit crunch arises. In this thesis, we address the question of if and how bank capital regulation may enhance cyclical patterns in lending. We analyze the sensitivity of the lending volume to changes of fundamental economic variables, called shocks, under a Value-at-Risk approach, under approaches with fixed risk weights, and under a laissez-faire economy. We endogenize the bank's risk-allocation and size decision. In particular, the deposit volume and the deposit interest rate are based on decisions made by the household and the bank. The deposit interest rate and the deposit volume reflect the bank's risk-taking and the regulatory constraints. Our results concerning pro-cyclicality lead to the conclusion that the effect of a given shock should be distinguished according to the type of the shock. Regulation effectively constrains bank lending after realized losses. Thus, equity shocks lead to pro-cyclical effects on lending. This observation is in line with common fears. The effects of expectation shocks, that is the effects of changes of distribution parameters or of borrowers' productivity, are dampened by regulation. More precisely, regulation effectively constrains bank lending when expectations turn more favorable. Thus, regulation may hamper economic recovery. In this respect, regulation is identified as non-pro-cyclical. We can observe counter-cyclical effects through regulation on the level of single loan volumes. These insights can be found regardless of the degree of risk sensitivity of the respective capital adequacy rule. Furthermore, a bank may grant higher loan volumes to less risky firms under risk-sensitive capital requirements than it would do under fixed requirements or under a laissez-faire regime. Including two periods shows that total loan volumes react to expectation shocks as in the one-period setting when the very period is considered at whose beginning the shock occurred. Likewise, the expected or average reaction of total loan volumes in the second period to the shifts thus implied in the bank's equity are in the same order of magnitude as in the one-period model. There is by no means an acceleration of sensitivities as such. Furthermore, this work emphasizes that enhanced risk-taking may occur under capital regulation without any interplay with other regulatory measures, such as deposit insurance schemes. Rather, the degree of risk-taking can be directly aligned with the sort of capital rules considered. A flat capital requirement always induces the bank to take more risk than under any other regime considered. The reduction in size is always compensated by taking more risk since this is the only possibility to raise the bank's expected final wealth. However, as capital requirements become risk-sensitive, our models yield mixed results. If loan repayments are normally distributed, the Value-at-Risk approach generally has no impact on risk-taking compared to the laissez-faire equilibrium

Entwicklungsförderung im außerschulischen Kinder- und Jugendsport: Evaluation der Programmwirksamkeit der Interventionsstudie PRimus

Zusammenfassung: Das Konzept "Psychosoziale Ressourcen im Sport" (Sygusch, Ein sportartenorientiertes Förderkonzept für Schule und Verein. Schorndorf: Hofmann, 2007) begründet methodische Maßnahmen zur systematischen Förderung der Ressourcen Selbstkonzept, Selbstwirksamkeit, Gruppenzusammenhalt und soziale Kompetenz. In der PRimus-Studie wurde dieses Konzept in den Sportarten Handball und Gerätturnen über 7 Monate im Trainingsalltag von 29 Trainingsgruppen (Alter: 12-16 Jahre) implementiert. Untersucht wurde u.a., ob das Konzept im außerschulischen Kinder- und Jugendsport wirksam ist. Hierfür wurde ein triangulativer Ansatz gewählt, indem die Veränderungen der Ressourcen mittels qualitativer Trainerbefragung (n = 39) sowie quantitativer Sportlerbefragung (IG: n = 374; KG: n = 270) zu je 3 Messzeitpunkten erfasst wurden. Die qualitativen Traineraussagen zeigen, dass durch die Interventionsmaßnahmen ressourcenstärkende Prozesse angeregt werden konnten, welche auf eine Förderung der Ressourcen deuten. In den quantitativ erfassten Ressourcen der Sportler liegen im Interventionsverlauf dagegen keine bedeutsamen Veränderungen vor, während Verhaltensänderungen der Trainer und der Mitsportler - unabhängig von den Interventionsmaßnahmen - einen Einfluss auf die Ressourcenentwicklung besitzen. Insgesamt bleibt festzuhalten, dass das - zugunsten der Umsetzbarkeit - breit angelegte Interventionskonzept den Nachweis der Wirkungen und der Wirksamkeit erschwert

Glycolytic and Non-glycolytic Functions of Mycobacterium tuberculosis Fructose-1,6-bisphosphate Aldolase, an Essential Enzyme Produced by Replicating and Non-replicating Bacilli

The search for antituberculosis drugs active against persistent bacilli has led to our interest in metallodependent class II fructose- 1,6-bisphosphate aldolase (FBA-tb), a key enzyme of gluconeogenesis absent from mammalian cells. Knock-out experiments at the fba-tb locus indicated that this gene is required for the growth of Mycobacterium tuberculosis on gluconeogenetic substrates and in glucose-containing medium. Surface labeling and enzymatic activity measurements revealed that this enzyme was exported to the cell surface of M. tuberculosis and produced under various axenic growth conditions including oxygen depletion and hence by non-replicating bacilli. Importantly, FBA-tb was also produced in vivo in the lungs of infected guinea pigs and mice. FBA-tb bound human plasmin(ogen) and protected FBA-tb-bound plasmin from regulation by α 2-antiplasmin, suggestive of an involvement of this enzyme in host/pathogen interactions. The crystal structures of FBA-tb in the native form and in complex with a hydroxamate substrate analog were determined to 2.35- and 1.9-Å resolution, respectively. Whereas inhibitor attachment had no effect on the plasminogen binding activity of FBA-tb, it competed with the natural substrate of the enzyme, fructose 1,6-bisphosphate, and substantiated a previously unknown reaction mechanism associated with metallodependent aldolases involving recruitment of the catalytic zinc ion by the substrate upon active site binding. Altogether, our results highlight the potential of FBA-tb as a novel therapeutic target against both replicating and non-replicating bacilli.Fil: Santangelo, María de la Paz. State University of Colorado - Fort Collins; Estados Unidos. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gest, Petra M.. State University of Colorado - Fort Collins; Estados UnidosFil: Guerin, Marcelo E.. Universidad del País Vasco; EspañaFil: Coinçon, Mathieu. University of Montreal; CanadáFil: Pham, Ha. State University of Colorado - Fort Collins; Estados UnidosFil: Ryan, Gavin. State University of Colorado - Fort Collins; Estados UnidosFil: Puckett, Susan E.. Cornell University; Estados UnidosFil: Spencer, John S.. State University of Colorado - Fort Collins; Estados UnidosFil: Gonzalez Juarrero, Mercedes. State University of Colorado - Fort Collins; Estados UnidosFil: Daher, Racha. Universite de Paris XI. Institut de Chimie Moléculaire et des Matériaux d'Orsay; FranciaFil: Lenaerts, Anne J.. State University of Colorado - Fort Collins; Estados UnidosFil: Schnappinger, Dirk. Cornell University; Estados UnidosFil: Therisod, Michel. Universite de Paris XI. Institut de Chimie Moléculaire et des Matériaux d'Orsay; FranciaFil: Ehrt, Sabine. Cornell University; Estados UnidosFil: Sygusch, Jurgen. University of Montreal; CanadáFil: Jackson, Mary. State University of Colorado - Fort Collins; Estados Unido

A conserved lysine residue of plant Whirly proteins is necessary for higher order protein assembly and protection against DNA damage

All organisms have evolved specialized DNA repair mechanisms in order to protect their genome against detrimental lesions such as DNA double-strand breaks. In plant organelles, these damages are repaired either through recombination or through a microhomology-mediated break-induced replication pathway. Whirly proteins are modulators of this second pathway in both chloroplasts and mitochondria. In this precise pathway, tetrameric Whirly proteins are believed to bind single-stranded DNA and prevent spurious annealing of resected DNA molecules with other regions in the genome. In this study, we add a new layer of complexity to this model by showing through atomic force microscopy that tetramers of the potato Whirly protein WHY2 further assemble into hexamers of tetramers, or 24-mers, upon binding long DNA molecules. This process depends on tetramer–tetramer interactions mediated by K67, a highly conserved residue among plant Whirly proteins. Mutation of this residue abolishes the formation of 24-mers without affecting the protein structure or the binding to short DNA molecules. Importantly, we show that an Arabidopsis Whirly protein mutated for this lysine is unable to rescue the sensitivity of a Whirly-less mutant plant to a DNA double-strand break inducing agent

Resolving polymorphs and radiation-driven effects in microcrystals using fixed-target serial synchrotron crystallography

The ability to determine high-quality, artefact-free structures is a challenge in micro-crystallography, and the rapid onset of radiation damage and requirement for a high-brilliance X-ray beam mean that a multi-crystal approach is essential. However, the combination of crystal-to-crystal variation and X-ray-induced changes can make the formation of a final complete data set challenging; this is particularly true in the case of metalloproteins, where X-ray-induced changes occur rapidly and at the active site. An approach is described that allows the resolution, separation and structure determination of crystal polymorphs, and the tracking of radiation damage in microcrystals. Within the microcrystal population of copper nitrite reductase, two polymorphs with different unit-cell sizes were successfully separated to determine two independent structures, and an X-ray-driven change between these polymorphs was followed. This was achieved through the determination of multiple serial structures from microcrystals using a high-throughput high-speed fixed-target approach coupled with robust data processing