661 research outputs found

    Is being competitive always an advantage? Competitiveness, gender, and labour market success

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    Competitiveness is increasingly discussed in behavioural economics as a personality trait that potentially relates to various labour market outcomes, such as career choices or compensation. This paper studies the association between individual competitiveness and premature employment and training contract termination from apprenticeships. We combine an incentivized measure of students’ competitiveness, elicited almost two years before the start of an apprenticeship, with administrative data on premature contract terminations. We find that not only the propensity towards competition depends on gender, but also that competitiveness is related differently to premature contract termination for men and women. For competitive men, we observe no correlation or, depending on the measure of competitiveness, that they are more successful in their apprenticeships. Competitive women, in contrast, are more likely to terminate their contract prematurely compared to non-competitive women, mostly due to a higher risk of conflicts with their employers

    The potential of transgenic legumes in integrated bruchid management: assessing the impact on bruchid parasitoids

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    Leguminous seeds are an important staple food and source of nutrition in many countries. Bruchid beetles (Coleoptera: Bruchidae) are responsible for the greatest post-harvest losses to stored legumes. A powerful strategy to control bruchid infestations is the combination of plant resistance factors and biological control provided by parasitoids. Potent resistance factors are α-amylase inhibitors (αAI) which inhibit the starch metabolism in sensitive insects. Genetic engineering has been used to transfer αAI-1 from the common bean (Phaseolus vulgaris) to other leguminous plants which are subsequently protected from the attack by several bruchid species. However, there are concerns regarding the effects that the expressed insecticidal protein might have on non-target organisms. Here, we present an approach to assess the impact of αAI-1 genetically modified legumes on bruchid parasitoids. Keywords: Risk assessment, Genetically modified plants, Non-target organisms; α-amylase inhibitor; αAI-

    European summer climate variability in a heterogeneous multi-model ensemble

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    Recent results from an enhanced greenhouse-gas scenario over Europe suggest that climate change might not only imply a general mean warming at the surface, but also a pronounced increase in interannual surface temperature variability during the summer season (Schär etal., Nature 427:332-336, 2004). It has been proposed that the underlying physical mechanism is related to land surface-atmosphere interactions. In this study we expand the previous analysis by including results from a heterogeneous ensemble of 11 high-resolution climate models from the PRUDENCE project. All simulations considered comprise 30-year control and enhanced greenhouse-gas scenario periods. While there is considerable spread in the models' ability to represent the observed summer variability, all models show some increase in variability for the scenario period, confirming the main result of the previous study. Averaged over a large-scale Central European domain, the models simulate an increase in the standard deviation of summer mean temperatures between 20 and 80%. The amplification occurs predominantly over land points and is particularly pronounced for surface temperature, but also evident for precipitation. It is also found that the simulated changes in Central European summer conditions are characterized by an emergence of dry and warm years, with early and intensified depletion of root-zone soil moisture. There is thus some evidence that the change in variability may be linked to the dynamics of soil-moisture storage and the associated feedbacks on the surface energy balance and precipitatio

    Clostridium difficile assoziierter Durchfall: "An emerging infection"

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    Zusammenfassung: Die Clostridium difficile assoziierte Diarrhö (CDAD) wird häufig als lästige und relativ banale Nebenwirkung einer Antibiotikatherapie angesehen. Während schon in den 1980er und 90er Jahren Morbidität, Mortalität und entsprechend auch die Kosten von CDAD beträchtlich waren, sind diese aufgrund des Aufkommens eines hochvirulenten Stamms von Clostridium difficile (C.difficile) Anfang2000 deutlich angestiegen. Die pathogenetischen Schlüsselereignisse sind Veränderungen der Darmflora nach Antibiotikagabe, Kolonisation mit einem toxinbildenden C.difficile und dessen intraluminale Vermehrung. Die Therapie besteht bei milden Formen im Absetzen der angeschuldigten Medikamente, bei mäßig bis schwer ausgeprägten Erkrankungen erfolgt die Gabe von Metronidazol oder Vancomycin per os. Als ultima ratio bei toxischem Megakolon muss die subtotale Hemikolektomie erwogen werden. Der verantwortungsvolle Einsatz von Antibiotika ("antibiotic stewardship") in Kombination mit spitalhygienischen Maßnahmen sind essenziell, um Ausbrüchen vorzubeugen und sie einzudämme

    Suppression of Sleep Spindle Rhythmogenesis in Mice with Deletion of CaV3.2 and CaV3.3 T-type Ca(2+) Channels.

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    STUDY OBJECTIVES: Low-threshold voltage-gated T-type Ca(2+) channels (T-channels or CaV3 channels) sustain oscillatory discharges of thalamocortical (TC) and nucleus Reticularis thalami (nRt) cells. The CaV3.3 subtype dominates nRt rhythmic bursting and mediates a substantial fraction of spindle power in the NREM sleep EEG. CaV3.2 channels are also found in nRt, but whether these contribute to nRt-dependent spindle generation is unexplored. We investigated thalamic rhythmogenesis in mice lacking this subtype in isolation (CaV3.2KO mice) or in concomitance with CaV3.3 deletion (CaV3.double-knockout (DKO) mice). METHODS: We examined discharge characteristics of thalamic cells and intrathalamic evoked synaptic transmission in brain slices from wild-type, CaV3.2KO and CaV3.DKO mice through patch-clamp recordings. The sleep profile of freely behaving CaV3.2KO and CaV3.DKO mice was assessed by polysomnographic recordings. RESULTS: CaV3.2 channel deficiency left nRt discharge properties largely unaltered, but additional deletion of CaV3.3 channels fully abolished low-threshold whole-cell Ca(2+) currents and bursting, and suppressed burst-mediated inhibitory responses in TC cells. CaV3.DKO mice had more fragmented sleep, with shorter NREM sleep episodes and more frequent microarousals. The NREM sleep EEG power spectrum displayed a relative suppression of the σ frequency band (10-15 Hz), which was accompanied by an increase in the δ band (1-4 Hz). CONCLUSIONS: Consistent with previous findings, CaV3.3 channels dominate nRt rhythmogenesis, but the lack of CaV3.2 channels further aggravates neuronal, synaptic, and EEG deficits. Therefore, CaV3.2 channels can boost intrathalamic synaptic transmission, and might play a modulatory role adjusting the relative presence of NREM sleep EEG rhythms

    A steerable UV laser system for the calibration of liquid argon time projection chambers

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    A number of liquid argon time projection chambers (LAr TPC's) are being build or are proposed for neutrino experiments on long- and short baseline beams. For these detectors a distortion in the drift field due to geometrical or physics reasons can affect the reconstruction of the events. Depending on the TPC geometry and electric drift field intensity this distortion could be of the same magnitude as the drift field itself. Recently, we presented a method to calibrate the drift field and correct for these possible distortions. While straight cosmic ray muon tracks could be used for calibration, multiple coulomb scattering and momentum uncertainties allow only a limited resolution. A UV laser instead can create straight ionization tracks in liquid argon, and allows one to map the drift field along different paths in the TPC inner volume. Here we present a UV laser feed-through design with a steerable UV mirror immersed in liquid argon that can point the laser beam at many locations through the TPC. The straight ionization paths are sensitive to drift field distortions, a fit of these distortion to the linear optical path allows to extract the drift field, by using these laser tracks along the whole TPC volume one can obtain a 3D drift field map. The UV laser feed-through assembly is a prototype of the system that will be used for the MicroBooNE experiment at the Fermi National Accelerator Laboratory (FNAL)

    NR2A at CA1 synapses is obligatory for the susceptibility of hippocampal plasticity to sleep loss.

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    A loss in the necessary amount of sleep alters expression of genes and proteins implicated in brain plasticity, but key proteins that render neuronal circuits sensitive to sleep disturbance are unknown. We show that mild (4-6 h) sleep deprivation (SD) selectively augmented the number of NR2A subunits of NMDA receptors on postsynaptic densities of adult mouse CA1 synapses. The greater synaptic NR2A content facilitated induction of CA3-CA1 long-term depression in the theta frequency stimulation range and augmented the synaptic modification threshold. NR2A-knock-out mice maintained behavioral response to SD, including compensatory increase in post-deprivation resting time, but hippocampal synaptic plasticity was insensitive to sleep loss. After SD, the balance between synaptically activated and slowly recruited NMDA receptor pools during temporal summation was disrupted. Together, these results indicate that NR2A is obligatory for the consequences of sleep loss on hippocampal synaptic plasticity. These findings could advance pharmacological strategies aiming to sustain hippocampal function during sleep restriction

    Elevation gradients of European climate change in the regional climate model COSMO-CLM

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    A transient climate scenario experiment of the regional climate model COSMO-CLM is analyzed to assess the elevation dependency of 21st century European climate change. A focus is put on near-surface conditions. Model evaluation reveals that COSMO-CLM is able to approximately reproduce the observed altitudinal variation of 2m temperature and precipitation in most regions and most seasons. The analysis of climate change signals suggests that 21st century climate change might considerably depend on elevation. Over most parts of Europe and in most seasons, near-surface warming significantly increases with elevation. This is consistent with the simulated changes of the free-tropospheric air temperature, but can only be fully explained by taking into account regional-scale processes involving the land surface. In winter and spring, the anomalous high-elevation warming is typically connected to a decrease in the number of snow days and the snow-albedo feedback. Further factors are changes in cloud cover and soil moisture and the proximity of low-elevation regions to the sea. The amplified warming at high elevations becomes apparent during the first half of the 21st century and results in a general decrease of near-surface lapse rates. It does not imply an early detection potential of large-scale temperature changes. For precipitation, only few consistent signals arise. In many regions precipitation changes show a pronounced elevation dependency but the details strongly depend on the season and the region under consideration. There is a tendency towards a larger relative decrease of summer precipitation at low elevations, but there are exceptions to this as wel

    Bayesian multi-model projection of climate: bias assumptions and interannual variability

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    Current climate change projections are based on comprehensive multi-model ensembles of global and regional climate simulations. Application of this information to impact studies requires a combined probabilistic estimate taking into account the different models and their performance under current climatic conditions. Here we present a Bayesian statistical model for the distribution of seasonal mean surface temperatures for control and scenario periods. The model combines observational data for the control period with the output of regional climate models (RCMs) driven by different global climate models (GCMs). The proposed Bayesian methodology addresses seasonal mean temperatures and considers both changes in mean temperature and interannual variability. In addition, unlike previous studies, our methodology explicitly considers model biases that are allowed to be time-dependent (i.e. change between control and scenario period). More specifically, the model considers additive and multiplicative model biases for each RCM and introduces two plausible assumptions ("constant bias” and "constant relationship”) about extrapolating the biases from the control to the scenario period. The resulting identifiability problem is resolved by using informative priors for the bias changes. A sensitivity analysis illustrates the role of the informative prior. As an example, we present results for Alpine winter and summer temperatures for control (1961-1990) and scenario periods (2071-2100) under the SRES A2 greenhouse gas scenario. For winter, both bias assumptions yield a comparable mean warming of 3.5-3.6°C. For summer, the two different assumptions have a strong influence on the probabilistic prediction of mean warming, which amounts to 5.4°C and 3.4°C for the "constant bias” and "constant relation” assumptions, respectively. Analysis shows that the underlying reason for this large uncertainty is due to the overestimation of summer interannual variability in all models considered. Our results show the necessity to consider potential bias changes when projecting climate under an emission scenario. Further work is needed to determine how bias information can be exploited for this tas
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