Ein Schulprogramm demokratisch entwickeln. OSZ II - Wirtschaft und Verwaltung Potsdam, Brandenburg

Zur Profilierung als ein zukunftsorientiertes und gefragtes Oberstufenzentrum entschloss sich das OSZ II Wirtschaft und Verwaltung Potsdam, sein Schulprogramm auf demokratischer Basis zu entwickeln. Die Schule fragte alle Beteiligten nach den Stärken und Schwächen des OSZ. Auf dieser Grundlage erarbeiteten die Lehrer/-innen in einem längeren Diskussionsprozess die konkreten Ziele für ihre Schulentwicklung

Effects of Progesterone and Its Antagonist Mifepristone on Progesterone Receptor A Expression in Human Umbilical Vein Endothelial Cells

Effects of female steroid hormones on endothelial cells are gaining increased importance due to several studies on the effects of hormonal treatment on cardiovascular risk. Recent data argue for an improvement of endothelium-derived relaxation and impaired vascular contraction by estradiol, whereas progesterone and testosterone might entail contrary effects. So far, gestagenic influence on endothelial cell physiology is poorly understood. Human umbilical vein endothelial cells (HUVECs) exposed to the female sex hormones estradiol and progesterone show expression of estrogen receptor-beta (ER beta) and progesterone receptor A (PR-A), and are negative for ER alpha and PR-B. The aim of this study was to analyze the expression and stimulation of PR-A and -B in HUVECs after stimulation with progesterone and PR antagonists that are commercially available. PR-B expression or upregulation was abrogated after application of progesterone or antagonists to HUVECs. Expression of PR-A could be significantly upregulated with progesterone and mifepristone. Unexpectedly, stimulation with the progesterone antagonist RU486 (mifepristone) was accomplished by an upregulation of PR-A expression in our study. We conclude that gestagenic effects on HUVECs independent of modulators are mediated via the PR-A. Copyright (C) 2009 S. Karger AG, Base

Learning about German farmers’ willingness to cooperate from public goods games and expert predictions

There is a growing interest in collective contracts to address agri-environmental policy goals at landscape scales. Yet, little is known about farmers’ general willingness to cooperate. We developed four treatments of a linear public goods game to investigate farmers’ willingness to cooperate: (1) heterogeneous endowments, (2) leading-by-example, (3) social norms, and (4) pinpointing the socially optimal solution. Based on a sample of 358 German farmers, we find that contributions reach more than twothirds of the initial endowment across different treatments on average. Nudging the socially optimal solution is the most effective treatment. In addition to the experiment, we elicited incentivized predictions on experimental outcomes from 212 experts. Expert beliefs on treatment effects appear to be calibrated on laboratory studies, highlighting the need to conduct, communicate, and discuss experimental studies outside the laboratory. Young female academics with an Economics background most accurately predict farmers’ behaviour in the experiment

Viewpoints on Cooperative Peatland Management: Expectations and Motives of Dutch Farmers

The European Union (EU) is globally the second highest emitter of greenhouse gases from drained peatlands. On the national level, 15% of agricultural peat soils in the Netherlands are responsible for 34% of agricultural emissions. Crucial to any successful policy is a better understanding of the behavioral change it will bring about among the target groups. Thus, we aim to explore farmers’ differing viewpoints to discuss how policy and planning can be improved to ensure landscape-scale climate mitigation on agriculturally used peatlands. Q methodology was used to interview fifteen farmers on Dutch peat soils, whereby 37 statements were ranked in a grid according to their level of agreement. Factor analysis revealed three main viewpoints: farmers with a higher peat proportion show an urgency in continuing to use their land (‘cooperative businesspeople’), while ‘independent opportunists’ are wary of cooperation compromising their sense of autonomy. Farmers who are ‘conditional land stewards’ are open to agriculture without drainage but require appropriate payments to do so. Future policy design must focus on providing support to farmers that go beyond compensation payments by providing information about funding sources as well as potential business models for peatland uses with raised water tables

Using farmers' ex ante preferences to design agri-environmental contracts: A systematic review

Ensuring that farmers' ex ante preferences are accounted for is crucial for the design of effective agri-environmental contracts. We present a systematic review of 127 discrete choice experiment (DCE) studies of farmers' preferences with respect to agri-environmental contracts. DCE studies evaluate two central features of farmers' behaviour: (1) their willingness to accept land use prescriptions, such as fertiliser use, application of pesticides, restrictions on cropping, livestock management, integration of silvopasture, maintaining soil health or water use restrictions; and (2) their responses to variations in incentive and commitment criteria, such as reward schemes, monitoring regimes, technical assistance, flexibility of agreements, administrative burden and collaborative implementation. Our analysis considers how these different elements are interlinked and applied in experiments to simulate farmers' decision-making processes. We examine recent methodological improvements in explaining farmer behaviour, including the accommodation of preference heterogeneity, the combining of discrete (enrolment) and continuous decisions, and the incorporation of farmers' sense of identity. DCEs have been applied for the ex ante analysis of different policy instruments to inform the European Common Agricultural Policy and agri-environmental schemes outside the EU. The results of this systematic review may be useful in informing the future design of such agri-environmental programmes. The database underpinning this systematic literature review may help peer scientists to (a) compare, validate and triangulate their own findings with respect to other experimental approaches, (b) use previous willingness-to-accept (WTA) measures as priors for their own study design, and (c) identify research gaps regarding farmers' preferences for agri-environmental measures

Prohibitin-mediated lifespan and mitochondrial stress implicate SGK-1, insulin/IGF and mTORC2 in C. elegans

This is an open-access article distributed under the terms of the Creative Commons Attribution License.Lifespan regulation by mitochondrial proteins has been well described, however, the mechanism of this regulation is not fully understood. Amongst the mitochondrial proteins profoundly affecting ageing are prohibitins (PHB-1 and PHB-2). Paradoxically, in C. elegans prohibitin depletion shortens the lifespan of wild type animals while dramatically extending that of metabolically compromised animals, such as daf-2-insulin-receptor mutants. Here we show that amongst the three kinases known to act downstream of daf-2, only loss of function of sgk-1 recapitulates the ageing phenotype observed in daf-2 mutants upon prohibitin depletion. Interestingly, signalling through SGK-1 receives input from an additional pathway, parallel to DAF-2, for the prohibitin-mediated lifespan phenotype. We investigated the effect of prohibitin depletion on the mitochondrial unfolded protein response (UPRmt). Remarkably, the lifespan extension upon prohibitin elimination, of both daf-2 and sgk-1 mutants, is accompanied by suppression of the UPRmtinduced by lack of prohibitin. On the contrary, gain of function of SGK-1 results in further shortening of lifespan and a further increase of the UPRmtin prohibitin depleted animals. Moreover, SGK-1 interacts with RICT-1 for the regulation of the UPRmtin a parallel pathway to DAF-2. Interestingly, prohibitin depletion in rict-1 loss of function mutant animals also causes lifespan extension. Finally, we reveal an unprecedented role for mTORC2-SGK-1 in the regulation of mitochodrial homeostasis. Together, these results give further insight into the mechanism of lifespan regulation by mitochondrial function and reveal a cross-talk of mitochondria with two key pathways, Insulin/IGF and mTORC2, for the regulation of ageing and stress response.This work was funded by grants from the European Research Council (ERC-2011-StG-281691) and the Spanish Ministerio de Economía y Competitividad (BFU2012-35509) to M.A.S. The study was also supported by grants from the Deutsche Forschungsgemeinschaft DFG (SFB746, SFB850) to R.B. and from BIOSS Centre for Biological Signalling Studies to R.B and M.A.S.Peer Reviewe

Combined flow cytometry and high-throughput image analysis for the study of essential genes in Caenorhabditis elegans

Background: Advances in automated image-based microscopy platforms coupled with high-throughput liquid workflows have facilitated the design of large-scale screens utilising multicellular model organisms such as Caenorhabditis elegans to identify genetic interactions, therapeutic drugs or disease modifiers. However, the analysis of essential genes has lagged behind because lethal or sterile mutations pose a bottleneck for high-throughput approaches, and a systematic way to analyse genetic interactions of essential genes in multicellular organisms has been lacking. Results: In C. elegans, non-conditional lethal mutations can be maintained in heterozygosity using chromosome balancers, commonly expressing green fluorescent protein (GFP) in the pharynx. However, gene expression or function is typically monitored by the use of fluorescent reporters marked with the same fluorophore, presenting a challenge to sort worm populations of interest, particularly at early larval stages. Here, we develop a sorting strategy capable of selecting homozygous mutants carrying a GFP stress reporter from GFP-balanced animals at the second larval stage. Because sorting is not completely error-free, we develop an automated high-throughput image analysis protocol that identifies and discards animals carrying the chromosome balancer. We demonstrate the experimental usefulness of combining sorting of homozygous lethal mutants and automated image analysis in a functional genomic RNA interference (RNAi) screen for genes that genetically interact with mitochondrial prohibitin (PHB). Lack of PHB results in embryonic lethality, while homozygous PHB deletion mutants develop into sterile adults due to maternal contribution and strongly induce the mitochondrial unfolded protein response (UPR mt ). In a chromosome-wide RNAi screen for C. elegans genes having human orthologues, we uncover both known and new PHB genetic interactors affecting the UPR mt and growth. Conclusions: The method presented here allows the study of balanced lethal mutations in a high-throughput manner. It can be easily adapted depending on the user's requirements and should serve as a useful resource for the C. elegans community for probing new biological aspects of essential nematode genes as well as the generation of more comprehensive genetic networks.European Research Council ERC-2011-StG-281691Ministerio de Economía y Competitividad BFU2012–3550

Kreisverkehre an Landstraßen

Kreisverkehre außerhalb bebauter Gebiete weisen im Vergleich zu Knotenpunkten mit und ohne LSA eine hohe Verkehrssicherheit auf. Von dem Merkblatt für die Anlage von Kreisverkehren abweichende Entwurfsvorgaben einzelner Bundesländer und ein hoher Anteil Fahrunfälle (insbesondere bei Dunkelheit), weisen jedoch auf ein Potential zur Erhöhung der Verkehrssicherheit durch bessere Erkennbarkeit der Kreisverkehre hin. Im Rahmen des Forschungsprojektes wurde das Unfallgeschehen in Deutschland und drei ausgewählten Bundesländern hinsichtlich der Unfallstruktur an außerörtlichen Kreisverkehren analysiert. Es zeigte sich, dass sich 60 % der Unfälle an außerörtlichen Kreisverkehren während Dämmerung und Dunkelheit ereignen und dass 40 % der Unfälle Alleinunfälle sind. Die Alleinunfälle wiesen dabei die höchste Unfallschwere auf und führen häufig zum Auffahren auf die Kreisinsel. In einer Detailanalyse wurden für 109 Kreisverkehre Lage-, Höhen-, Beschilderungs- und Markierungspläne sowie Verkehrs- und Unfalldaten recherchiert. Unter Verwendung generalisierter linearer Modelle wurde der Einfluss verschiedener Ge¬staltungselemente auf das Unfallgeschehen untersucht. Dabei wurden u. a. folgende Einflussfaktoren identifiziert: • Zufahrten mit Abkröpfung und Verschwenkung im Annäherungsbereich weisen geringere Unfallraten als Zufahrten mit gestreckter Linienführung auf. • Zufahrten mit großem Ablenkungswinkel haben höhere Unfallraten als Zufahrten mit mittlerem Ablenkungswinkel. • Zufahrten mit breitem Fahrbahnteiler in dreieckiger Form weisen geringere Unfallraten als Zufahrten mit schmalem Fahrbahnteiler mit gerader Bordführung auf. Ergänzend wurden Fahrverhaltensanalysen und lichttechnische Untersuchungen an mehr als 30 Kreisverkehrszufahrten durchgeführt. Das beobachtete Geschwindigkeits- und Spurverhalten bestätigt die Erkenntnisse der Unfallanalyse im Hinblick auf die Linienführung im Annäherungsbereich und die Form des Fahrbahnteilers. Anhand der lichttechnischen Analysen (Leuchtdichtemessungen) konnte gezeigt werden, dass durch retroreflektierende Markierungsnägel auf den Bordsteinen der Fahrbahnteiler und der Kreisinsel die Erkennbarkeit von außerörtlichen Kreisverkehren bei Dunkelheit verbessert werden kann.Literature consistently finds a higher level of safety at roundabouts compared to other types of intersections. However, some studies indicate that there is still a lack of safety on rural roundabouts. Particularly high approaching speeds combined with insufficient perceptibility of roundabouts can cause accidents when drivers lose control of their vehicle (especially during nighttime). The goal of this study is to analyze correlates of safety at rural roundabouts in Germany and to investigate opportunities to improve their safety. The analysis of accident characteristics in data from official statistics shows that 60% of all accidents happen in twilight and at night time and that four out of ten accidents are single-vehicle accidents. Single-vehicle accidents have the highest severity and usually end up on the central island of roundabouts. For detailed accident analysis of 109 roundabouts, information on road design, signage, traffic volumes, and accidents was collected for each approach. Using generalized linear models, the following effects of roundabout design on accident risk were found: • Approaches with a curvilinear alignment or a chicane have significant lower accident rates than approaches with straight alignment. • Approaches with high angles of deflection have higher accident rates than approaches with moderate angles of deflection. • Wide splitter islands with triangle shape provide lower accident rates than narrow splitter islands with straight curb.4 Finally, observations of driving behavior and photometric studies were conducted at more than 30 approaches of rural roundabouts. The influence of approach alignment on speed behavior and the shape of splitter islands on track behavior proved the results obtained by the accident analysis. Photometric studies showed that the usage of retroreflective elements on the curb of the splitter island increase the visibility of rural roundabouts during the night