13,162 research outputs found

    Fourier Mukai Transforms for Gorenstein Schemes

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    We extend to singular schemes with Gorenstein singularities or fibered in schemes of that kind Bondal and Orlov's criterion for an integral functor to be fully faithful. We also contemplate a criterion for equivalence. We offer a proof that is new even if we restrict to the smooth case. In addition, we prove that for locally projective Gorenstein morphisms, a relative integral functor is fully faithful if and only if its restriction to each fibre also is it. These results imply the invertibility of the usual relative Fourier-Mukai transform for an elliptic fibration as a direct corollary.Comment: Final version. To appear in Advances in Mathematic

    A virtual object-location task for children: Gender and videogame experience influence navigation; age impacts memory and completion time

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    The use of virtual reality-based tasks for studying memory has increased considerably. Most of the studies that have looked at child population factors that influence performance on such tasks have been focused on cognitive variables. However, little attention has been paid to the impact of non-cognitive skills. In the present paper, we tested 52 typically-developing children aged 5-12 years in a virtual object-location task. The task assessed their spatial short-term memory for the location of three objects in a virtual city. The virtual task environment was presented using a 3D application consisting of a 120" stereoscopic screen and a gamepad interface. Measures of learning and displacement indicators in the virtual environment, 3D perception, satisfaction, and usability were obtained. We assessed the children's videogame experience, their visuospatial span, their ability to build blocks, and emotional and behavioral outcomes. The results indicate that learning improved with age. Significant effects on the speed of navigation were found favoring boys and those more experienced with videogames. Visuospatial skills correlated mainly with ability to recall object positions, but the correlation was weak. Longer paths were related with higher scores of withdrawal behavior, attention problems, and a lower visuospatial span. Aggressiveness and experience with the device used for interaction were related with faster navigation. However, the correlations indicated only weak associations among these variables

    A Comparison of Fluorescence and ETR Between Malosma laurina and Rhus integrifolia

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    Malosma laurina and Rhus integrifolia are both native species to the Santa Monica Mountains and belong to the same family, Anacardiaceae. The two natives have lived alongside each other but in recent years M. laurina has been heavily affected by the prolonged drought. The Malosma laurina population in the Santa Monica Mountains has withstood wildfires and droughts, and has remained relatively stable and healthy up until recently. A recent Pepperdine graduate published her findings explaining the high levels of dieback in Malosma laurina and attributed it to the fungus, B. dothidea. We hypothesized that Rhus integrifolia would have higher fluorescence and ETR rates because there have been no recorded cases of Rhus integrifolia being infected by the fungus or that it would physiologically outperform M. laurina. We concluded that there was no significant difference in light and dark adapted fluorescence rates between both plants. However, Malosma laurina proved to have a significanty higher electron transport rate

    Engage D2.6 Annual combined thematic workshops progress report (series 2)

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    The preparation, organisation and conclusions from the thematic challenge workshops, two ad hoc technical workshops, a technical session on data and a MET/ENV workshop held in 2019 and 2020 are described. Partly due to Covid-19, two of the 2020 thematic challenge workshops scheduled to take place at the end of 2020 were re-scheduled to January 2021. We also report on the preparation for these two workshops, while the conclusions will be included in the next corresponding deliverable
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