25 research outputs found

    Indirect contact predicts direct contact : longitudinal evidence and the mediating role of intergroup anxiety

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    While the effects of direct and indirect forms of contact on intergroup relations are well documented, little is known about their longitudinal co-development. Based on the social-psychological literature, we hypothesize that indirect contact predicts future direct contact by reducing intergroup anxiety. Across five longitudinal studies (Study 1: German adults, N = 560; Study 2: German, Dutch, and Swedish school students, N = 6,600; Study 3: Northern Irish children, N = 1,593; Study 4: Northern Irish adults, N = 404; Study 5: German adults, N = 735), we systematically examined this effect, and further tested the mediating role of intergroup anxiety in Studies 3 to 5. Cross-lagged models provided consistent evidence for the positive effect of indirect contact on future direct contact, while a reduction in intergroup anxiety mediates this effect in most models. Results highlight the importance of indirect contact, which has the potential to increase direct contact, and thus promote social cohesion in diverse contexts, over time.PostprintPeer reviewe

    A Soft Robotic Actuator System for in vivo Modeling of Normal Pressure Hydrocephalus

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    OBJECTIVE: The intracranial pressure (ICP) affects the dynamics of cerebrospinal fluid (CSF) and its waveform contains information that is of clinical importance in medical conditions such as hydrocephalus. Active manipulation of the ICP waveform could enable the investigation of pathophysiological processes altering CSF dynamics and driving hydrocephalus. METHODS: A soft robotic actuator system for intracranial pulse pressure amplification was developed to model normal pressure hydrocephalus in vivo. Different end actuators were designed for intraventricular implantation and manufactured by applying cyclic tensile loading on soft rubber tubing. Their mechanical properties were investigated, and the type that achieved the greatest pulse pressure amplification in an in vitro simulator of CSF dynamics was selected for application in vivo. A hydraulic actuation device based on a linear voice coil motor was developed to enable automated and fast operation of the end actuators. The combined system was validated in an acute ovine pilot in vivo study. RESULTS: In vitro results show that variations in the used materials and manufacturing settings altered the end actuator's dynamic properties, such as the pressure-volume characteristics. In the in vivo model, a cardiac-gated actuation volume of 0.125 mL at a heart rate of 62 bpm caused an increase of 205% in mean peak-to-peak amplitude but only an increase of 1.3% in mean ICP. CONCLUSION: The introduced soft robotic actuator system is capable of ICP waveform manipulation. SIGNIFICANCE: Continuous amplification of the intracranial pulse pressure could enable in vivo modeling of normal pressure hydrocephalus and shunt system testing under pathophysiological conditions to improve therapy for hydrocephalus

    The Interplay Between Host Genetic Variation, Viral Replication, and Microbial Translocation in Untreated HIV-Infected Individuals

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    Systemic immune activation, a major determinant of human immunodeficiency virus (HIV) disease progression, is the result of a complex interplay between viral replication, dysregulation of the immune system, and microbial translocation due to gut mucosal damage. Although human genetic variants influencing HIV load have been identified, it is unknown how much the host genetic background contributes to interindividual differences in other determinants of HIV pathogenesis such as gut damage and microbial translocation. Using samples and data from 717 untreated participants in the Swiss HIV Cohort Study and a genome-wide association study design, we searched for human genetic determinants of plasma levels of intestinal fatty acid-binding protein (I-FABP/FABP2), a marker of gut damage, and of soluble CD14 (sCD14), a marker of lipopolysaccharide bioactivity and microbial translocation. We also assessed the correlations between HIV load, sCD14, and I-FABP. Although we found no genome-wide significant determinant of the tested plasma markers, we observed strong associations between sCD14 and both HIV load and I-FABP, shedding new light on the relationships between processes that drive progression of untreated HIV infectio

    Toward a methodical framework for comprehensively assessing forest multifunctionality

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    Biodiversity-ecosystem functioning (BEF) research has extended its scope from communities that are short-lived or reshape their structure annually to structurally complex forest ecosystems. The establishment of tree diversity experiments poses specific methodological challenges for assessing the multiple functions provided by forest ecosystems. In particular, methodological inconsistencies and nonstandardized protocols impede the analysis of multifunctionality within, and comparability across the increasing number of tree diversity experiments. By providing an overview on key methods currently applied in one of the largest forest biodiversity experiments, we show how methods differing in scale and simplicity can be combined to retrieve consistent data allowing novel insights into forest ecosystem functioning. Furthermore, we discuss and develop recommendations for the integration and transferability of diverse methodical approaches to present and future forest biodiversity experiments. We identified four principles that should guide basic decisions concerning method selection for tree diversity experiments and forest BEF research: (1) method selection should be directed toward maximizing data density to increase the number of measured variables in each plot. (2) Methods should cover all relevant scales of the experiment to consider scale dependencies of biodiversity effects. (3) The same variable should be evaluated with the same method across space and time for adequate larger-scale and longer-time data analysis and to reduce errors due to changing measurement protocols. (4) Standardized, practical and rapid methods for assessing biodiversity and ecosystem functions should be promoted to increase comparability among forest BEF experiments. We demonstrate that currently available methods provide us with a sophisticated toolbox to improve a synergistic understanding of forest multifunctionality. However, these methods require further adjustment to the specific requirements of structurally complex and long-lived forest ecosystems. By applying methods connecting relevant scales, trophic levels, and above? and belowground ecosystem compartments, knowledge gain from large tree diversity experiments can be optimized

    Similar estimates of temperature impacts on global wheat yield by three independent methods

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    The potential impact of global temperature change on global crop yield has recently been assessed with different methods. Here we show that grid-based and point-based simulations and statistical regressions (from historic records), without deliberate adaptation or CO2 fertilization effects, produce similar estimates of temperature impact on wheat yields at global and national scales. With a 1 °C global temperature increase, global wheat yield is projected to decline between 4.1% and 6.4%. Projected relative temperature impacts from different methods were similar for major wheat-producing countries China, India, USA and France, but less so for Russia. Point-based and grid-based simulations, and to some extent the statistical regressions, were consistent in projecting that warmer regions are likely to suffer more yield loss with increasing temperature than cooler regions. By forming a multi-method ensemble, it was possible to quantify ‘method uncertainty’ in addition to model uncertainty. This significantly improves confidence in estimates of climate impacts on global food security.<br/

    Indirect contact predicts direct contact:longitudinal evidence and the mediating role of intergroup anxiety

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    While the effects of direct and indirect forms of contact on intergroup relations are well documented, little is known about their longitudinal co-development. Based on the social-psychological literature, we hypothesize that indirect contact predicts future direct contact by reducing intergroup anxiety. Across five longitudinal studies (Study 1: German adults, N = 560; Study 2: German, Dutch, and Swedish school students, N = 6,600; Study 3: Northern Irish children, N = 1,593; Study 4: Northern Irish adults, N = 404; Study 5: German adults, N = 735), we systematically examined this effect, and further tested the mediating role of intergroup anxiety in Studies 3 to 5. Cross-lagged models provided consistent evidence for the positive effect of indirect contact on future direct contact, while a reduction in intergroup anxiety mediates this effect in most models. Results highlight the importance of indirect contact, which has the potential to increase direct contact, and thus promote social cohesion in diverse contexts, over time
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