113 research outputs found

    DM Plans for Blended Objects

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    LSST Data Management baseline plan for measurements of blended objects and crowded field photometry

    Safety of Lithium Nickel Cobalt Aluminum Oxide Battery Packs in Transit Bus Applications

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    The future of mass transportation is clearly moving toward the increased efficiency and greenhouse gas reduction of hybrid and electric vehicles. With the introduction of high-power/high-energy storage devices such as lithium ion battery systems serving as a key element in the system, valid safety and security concerns emerge. This is especially true when the attractive high-specific-energy and power-chemistry lithium nickel cobalt aluminum oxide (NCA) is used. This chemistry provides great performance but presents a safety and security risk when used in large quantities, such as for a large passenger bus. If triggered, the cell can completely fuel its own fire, and this triggering event occurs more easily than one may think. To assist engineers and technicians in this transfer from the use of primarily fossil fuels to battery energy storage on passenger buses, the Battery Application Technology Testing and Energy Research Laboratory (BATTERY) of the Thomas D. Larson Pennsylvania Transportation Institute (LTI) in the College of Engineering at The Pennsylvania State University partnered with advanced chemistry battery and material manufacturers to study the safety concerns of an NCA battery chemistry for use in transit buses. The research team ran various experiments on cells and modules, studying rarely considered thermal events or venting events. Special considerations were made to gather supporting information to help better understand what happens, and most importantly how to best mitigate these events and/or manage them when they occur on a passenger bus. The research team found that the greatest safety concern when using such a high-energy chemistry is ensuring passenger safety when a cell’s electrolyte boils and causes the ventilation of high-temperature toxic material. A cell-venting event can be triggered by a variety of scenarios with differing levels of likelihood. Also, though the duration of a venting event is relatively short, on the order of just a few seconds, the temperature of the venting material and cell is extremely high. During a venting event, the high-pressure, burning gases tend to burn holes in nearby packaging materials. Most interestingly, the team discovered that following a venting event the large-format cells tested immediately reached and remained at extremely high external skin temperatures for very long periods, on the order of hours. The majority of this report covers the testing designed to better understand how high-energy cells of this chemistry fail and what materials can be used to manage these failures in a way that increases passenger survivability

    Study of the Spectral and Temporal Characteristics of X-Ray Emission of the Gamma-Ray Binary LS 5039 with Suzaku

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    We report on the results from Suzaku broadband X-ray observations of the galactic binary source LS5039. The Suzaku data, which have continuous coverage of more than one orbital period, show strong modulation of the X-ray emission at the orbital period of this TeV gamma-ray emitting system.The X-ray emission shows a minimum at orbital phase ~ 0.1, close to the so-called superior conjunction of the compact object, and a maximum at phase ~0.7, very close to the inferior conjunction of the compact object. The X-ray spectral data up to 70 keV are described by a hard power-law with a phase-dependent photon index which varies within Gamma ~1.45 - 1.61. The amplitude of the flux variation is a factor of 2.5, but is significantly less than that of the factor ~8 variation in the TeV flux. Otherwise the two light curves are similar, but not identical. Although periodic X-ray emission has been found from many galactic binary systems, the Suzaku result implies a phenomenon different from the "standard" origin of X-rays related to the emission of the hot accretion plasma formed around the compact companion object. The X-ray radiation of LS5039is likely to be linked to very-high-energy electrons which are also responsible for the TeV gamma-ray emission. While the gamma-rays are the result of inverse Compton scattering by electrons on optical stellar photons, X-rays are produced via synchrotron radiation. Yet, while the modulation of the TeV gamma-ray signal can be naturally explained by the photon-photon pair production and anisotropic inverse Compton scattering, the observed modulation of synchrotron X-rays requires an additional process, the most natural one being adiabatic expansion in the radiation production region.Comment: 9 pages, 7 figures, Accepted for publication in ApJ, references fixed, a few typos correcte

    Executive function does not predict coping with symptoms in stable patients with a diagnosis of schizophrenia

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    <p>Abstract</p> <p>Background</p> <p>Associations between coping with and control over psychotic symptoms were examined using the Maastricht Assessment of Coping Strategies-24, testing the hypothesis that the cognitive domain of executive functioning predicted quality and quantity of coping.</p> <p>Methods</p> <p>MACS-24 was administered to 32 individuals with a diagnosis of schizophrenia. For each of 24 symptoms, experience of distress, type of coping and the resulting degree of perceived control were assessed. Coping types were reduced to two contrasting coping categories: symptomatic coping (SC) and non-symptomatic coping (NSC; combining active problem solving, passive illness behaviour, active problem avoiding, and passive problem avoiding). Cognitive functioning was assessed using the GIT (Groninger Intelligence Test), the Zoo map (BADS: Behavioural Assessment of Dysexecutive function), Stroop-test and Trail making.</p> <p>Results</p> <p>Cognitive function was not associated with frequency of coping, nor did cognitive function differentially predict SC or NSC. Cognitive function similarly was not associated with symptom distress or level of perceived control over the symptom.</p> <p>Conclusion</p> <p>There was no evidence that cognitive function predicts quantity or quality of coping with symptoms in people with a diagnosis of schizophrenia. Variation in the realm of emotion regulation and social cognition may be more predictive of coping with psychotic symptoms.</p

    Transcription Factors Bind Thousands of Active and Inactive Regions in the Drosophila Blastoderm

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    Identifying the genomic regions bound by sequence-specific regulatory factors is central both to deciphering the complex DNA cis-regulatory code that controls transcription in metazoans and to determining the range of genes that shape animal morphogenesis. We used whole-genome tiling arrays to map sequences bound in Drosophila melanogaster embryos by the six maternal and gap transcription factors that initiate anterior–posterior patterning. We find that these sequence-specific DNA binding proteins bind with quantitatively different specificities to highly overlapping sets of several thousand genomic regions in blastoderm embryos. Specific high- and moderate-affinity in vitro recognition sequences for each factor are enriched in bound regions. This enrichment, however, is not sufficient to explain the pattern of binding in vivo and varies in a context-dependent manner, demonstrating that higher-order rules must govern targeting of transcription factors. The more highly bound regions include all of the over 40 well-characterized enhancers known to respond to these factors as well as several hundred putative new cis-regulatory modules clustered near developmental regulators and other genes with patterned expression at this stage of embryogenesis. The new targets include most of the microRNAs (miRNAs) transcribed in the blastoderm, as well as all major zygotically transcribed dorsal–ventral patterning genes, whose expression we show to be quantitatively modulated by anterior–posterior factors. In addition to these highly bound regions, there are several thousand regions that are reproducibly bound at lower levels. However, these poorly bound regions are, collectively, far more distant from genes transcribed in the blastoderm than highly bound regions; are preferentially found in protein-coding sequences; and are less conserved than highly bound regions. Together these observations suggest that many of these poorly bound regions are not involved in early-embryonic transcriptional regulation, and a significant proportion may be nonfunctional. Surprisingly, for five of the six factors, their recognition sites are not unambiguously more constrained evolutionarily than the immediate flanking DNA, even in more highly bound and presumably functional regions, indicating that comparative DNA sequence analysis is limited in its ability to identify functional transcription factor targets

    Does Corruption Erode Trust in Government? Evidence from a Recent Surge of Local Scandals in Spain

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    Bypassing Progressive Taxation: Fraud and Base Erosion in the Spanish Income Tax (1970-2001)

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    Decomposing the Impact of Immigration on House Prices

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