2,867 research outputs found

    ASWA Highlights of the Year

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    Simon-Task Reveals Balanced Visuomotor Control in Experienced Video-Game Players

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    Both short and long-term video-game play may result in superior performance on visual and attentional tasks. To further these findings, we compared the performance of experienced male video-game players (VGPs) and non-VGPs on a Simon-task. Experienced-VGPs began playing before the age of 10, had a minimum of 8 years of experience and a minimum play time of over 20 h per week over the past 6 months. Our results reveal a significantly reduced Simon-effect in experienced-VGPs relative to non-VGPs. However, this was true only for the right-responses, which typically show a greater Simon-effect than left-responses. In addition, experienced-VGPs demonstrated significantly quicker reaction times and more balanced left-versus-right-hand performance than non-VGPs. Our results suggest that experienced-VGPs can resolve response-selection conflicts more rapidly for right-responses than non-VGPs, and this may in part be underpinned by improved bimanual motor control

    Rubber friction: role of the flash temperature

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    When a rubber block is sliding on a hard rough substrate, the substrate asperities will exert time-dependent deformations of the rubber surface resulting in viscoelastic energy dissipation in the rubber, which gives a contribution to the sliding friction. Most surfaces of solids have roughness on many different length scales, and when calculating the friction force it is necessary to include the viscoelastic deformations on all length scales. The energy dissipation will result in local heating of the rubber. Since the viscoelastic properties of rubber-like materials are extremely strongly temperature dependent, it is necessary to include the local temperature increase in the analysis. At very low sliding velocity the temperature increase is negligible because of heat diffusion, but already for velocities of order 0.01 m/s the local heating may be very important. Here I study the influence of the local heating on the rubber friction, and I show that in a typical case the temperature increase results in a decrease in rubber friction with increasing sliding velocity for v > 0.01 m/s. This may result in stick-slip instabilities, and is of crucial importance in many practical applications, e.g., for the tire-road friction, and in particular for ABS-breaking systems.Comment: 22 pages, 27 figure

    Permafrost - physical aspects and carbon cycling, databases and uncertainties

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    Permafrost is defined as ground that remains below 0°C for at least 2 consecutive years. About 24% of the northern hemisphere land area is underlain by permafrost. The thawing of permafrost has the potential to influence the climate system through the release of carbon (C) from northern high latitude terrestrial ecosystems, but there is substantial uncertainty about the sensitivity of the C cycle to thawing permafrost. Soil C can be mobilized from permafrost in response to changes in air temperature, directional changes in water balance, fire, thermokarst, and flooding. Observation networks need to be implemented to understand responses of permafrost and C at a range of temporal and spatial scales. The understanding gained from these observation networks needs to be integrated into modeling frameworks capable of representing how the responses of permafrost C will influence the trajectory of climate in the future

    Efficient wide-field radio interferometry response

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    Radio interferometers do not measure the sky brightness distribution directly but rather a modified Fourier transform of it. Imaging algorithms, thus, need a computational representation of the linear measurement operator and its adjoint, irrespective of the specific chosen imaging algorithm. In this paper, we present a C++ implementation of the radio interferometric measurement operator for wide-field measurements which is based on "improved ww-stacking". It can provide high accuracy (down to 1012\approx 10^{-12}), is based on a new gridding kernel which allows smaller kernel support for given accuracy, dynamically chooses kernel, kernel support and oversampling factor for maximum performance, uses piece-wise polynomial approximation for cheap evaluations of the gridding kernel, treats the visibilities in cache-friendly order, uses explicit vectorisation if available and comes with a parallelisation scheme which scales well also in the adjoint direction (which is a problem for many previous implementations). The implementation has a small memory footprint in the sense that temporary internal data structures are much smaller than the respective input and output data, allowing in-memory processing of data sets which needed to be read from disk or distributed across several compute nodes before.Comment: 13 pages, 8 figure

    Gene Deletion of the Kinin Receptor B1 Attenuates Cardiac Inflammation and Fibrosis During the Development of Experimental Diabetic Cardiomyopathy

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    Objective: Diabetic cardiomyopathy is associated with increased mortality in patients with diabetes mellitus. The underlying pathology of this disease is still under discussion. We studied the role of the kinin B1 receptor on the development of experimental diabetic cardiomyopathy. Research Design and Methods: We utilized B1 receptor knockout mice and investiged cardiac inflammation, fibrosis and oxidative stress after induction of streptozotocin (STZ)-induced diabetes mellitus. Furthermore, the left ventricular function was measured by pressure-volume loops after 8 weeks of diabetes mellitus. Results: B1 receptor knockout mice showed an attenuation of diabetic cardiomyopathy with improved systolic and diastolic function in comparison with diabetic control mice. This was associated with a decreased activation state of the MAP kinase p38, less oxidative stress as well as normalized cardiac inflammation, shown by fewer invading cells and, no increase in matrix metalloproteinase-9 as well as the chemokine CXCL-5. Furthermore, the pro-fibrotic connective tissue growth factor was normalized, leading to a reduction in cardiac fibrosis despite severe hyperglycemia in mice lacking the B1 receptor. Conclusion: These findings suggest that the B1 receptor is detrimental in diabetic cardiomyopathy in that it mediates inflammatory and fibrotic processes. These insights might have useful implications on future studies utilizing B1 receptor antagonists for treatment of human diabetic cardiomyopathy
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