512 research outputs found

    The Curious Case of Abell 2256

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    Abell 2256 is a rich, nearby (z=0.0594) galaxy cluster that has significant evidence of merger activity. We present new radio and X-ray observations of this system. The low-frequency radio images trace the diffuse synchrotron emission of the Mpc-scale radio halo and relics as well as a number of recently discovered, more compact, steep spectrum sources. The spectral index across the relics steepens from the north-west toward the south-east. Analysis of the spectral index gradients between low and and high-frequencies shows spectral differences away from the north-west relic edge such that the low-frequency index is significantly flatter than the high frequency spectral index near the cluster core. This trend would be consistent with an outgoing merger shock as the origin of the relic emission. New X-ray data from XMM-Newton reveal interesting structures in the intracluster medium pressure, entropy and temperature maps. The pressure maps show an overall low pressure core co-incident with the radio halo emission, while the temperature maps reveal multiple regions of cool emission within the central regions of Abell 2256. The two cold fronts in Abell 2256 both appear to have motion in similar directions.Comment: 4 pages, 3 figures, proceedings of contributed talk at "Non-Thermal Phenomena in Colliding Galaxy Clusters", held in Nice, 15-18 November 2010. To be published in Mem. S.A.I

    Using Deep Learning and 360 Video to Detect Eating Behavior for User Assistance Systems

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    The rising prevalence of non-communicable diseases calls for more sophisticated approaches to support individuals in engaging in healthy lifestyle behaviors, particularly in terms of their dietary intake. Building on recent advances in information technology, user assistance systems hold the potential of combining active and passive data collection methods to monitor dietary intake and, subsequently, to support individuals in making better decisions about their diet. In this paper, we review the state-of-the-art in active and passive dietary monitoring along with the issues being faced. Building on this groundwork, we propose a research framework for user assistance systems that combine active and passive methods with three distinct levels of assistance. Finally, we outline a proof-of-concept study using video obtained from a 360-degree camera to automatically detect eating behavior from video data as a source of passive dietary monitoring for decision support

    Children as covert human intelligence sources: spies first, children second

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    The Covert Human Intelligence Sources (Criminal Conduct) Act 2021 empowers the police, and other authorities, throughout the UK to use children as Covert Human Intelligence Sources (CHIS) and to authorise these children to engage in criminality, with no criminal liability, in return for information. In this paper we analyse the risk of severe physical and emotional harm that children face when acting as a CHIS and engaging in criminal behaviour to preserve their cover. This practice of using a child as a CHIS and encouraging children to engage in criminal conduct also runs counter to the Youth Justice Board for England and Wales’ ‘Child First’ vision of a youth justice system that respects children rights and operates in children’s best interests. Throughout the article we argue that, despite the existing safeguards, the emphasis should be on helping children to escape a criminal lifestyle, rather than entrenching them further in a life of criminality by encouraging them to act as a CHIS

    Desiccation rates of Rana sylvatica, Rana clamitans, and Bufo americanus in a fragmented forest

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    Abstract only availableHabitat loss and fragmentation are the primary causes in the declines of amphibian populations. Farming, urban sprawl, and logging have created a mosaic of developed and undeveloped land that may create barriers between aquatic breeding sites and terrestrial refuges. While ponds and wetlands are important in early development and breeding, many species spend their adult lives foraging in the terrestrial environment surrounding a breeding site. An amphibian's ability to move and forage in a terrestrial environment is determined by their capacity to remain hydrated. We compared desiccation rates of wood frogs (Rana sylvatica), green frogs (Rana clamitans), and American toads (Bufo americanus) juveniles in different microhabitats of a forest and a clear-cut to determine how they might affect the terrestrial activity of amphibians. Using the experimental arrays created by LEAP (Land use Effects on Amphibian Populations) at Daniel Boone Conservation Area we set up cylindrical wire mesh enclosures in forest drainages, forest ridges, brush piles in clear cuts, and open areas in clear cuts at two ponds. Animals were placed in the enclosures during the evening and weighed every six hours for twenty-four hours. Soil moisture, and soil temperature were also measured every six hours. Analysis of variance with repeated measures was used to compare percent water loss in the habitat treatments. All frogs lost water; however, water loss was greater in the day compared to night. Brush piles within the clear cut slowed water loss compared to open areas in the clear cuts, and animals on forest ridges lost more water than those in forest drainages. Our results reinforce the need to protect forest drainages as terrestrial refuges and illustrate that clear cutting, even with brush piles as cover, may negatively affect the delicate balance of mortality and survivorship in juveniles, therefore threatening the future of a population.Life Sciences Undergraduate Research Opportunity Progra

    Cosmology and Fermion Confinement in a Scalar-Field-Generated Domain Wall Brane in Five Dimensions

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    We consider a brane generated by a scalar field domain wall configuration in 4+1 dimensions, interpolating, in most cases, between two vacua of the field. We study the cosmology of such a system in the cases where the effective four-dimensional brane metric is de Sitter or anti de Sitter, including a discussion of the bulk coordinate singularities present in the de-Sitter case. We demonstrate that a scalar field kink configuration can support a brane with dS4_4 cosmology, despite the presence of coordinate singularities in the metric. We examine the trapping of fermion fields on the domain wall for nontrivial brane cosmology.Comment: 29 pages, 12 figures; minor changes, accepted by JHE

    Impact of smoking status and chronic obstructive pulmonary disease on pulmonary complications post lung cancer surgery

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    Introduction Smoking and chronic obstructive pulmonary disease (COPD) are associated with an increased risk of post-operative pulmonary complications (PPCs) following lung cancer resection. It remains unclear whether smoking cessation reduces this risk. Methods Retrospective review of a large, prospectively collected database of over 1000 consecutive resections for lung cancer in a quaternary lung cancer centre over a 23-year period. Results One thousand and thirteen patients underwent curative-intent lobectomy or pneumonectomy between 1995 and 2018. Three hundred and sixty-two patients (36%) were ex-smokers, 314 (31%) were current smokers and 111 (11%) were never smokers. A pre-operative diagnosis of COPD was present in 57% of current smokers, 57% of ex-smokers and 20% of never smokers. Just over 25% of patients experienced a PPC. PPCs were more frequent in current smokers compared to never smokers (27% vs 17%, p = 0.036), however, no difference was seen between current and ex-smokers (p = 0.412) or between never and ex-smokers (p = 0.113). Those with a diagnosis of COPD, independent of smoking status, had a higher frequency of both PPCs (65% vs 35%, p<0.01) and overall complications (60% vs 40%, p<0.01) as well as a longer length of hospital stay (10 vs 9 days, p<0.01). Conclusion Smoking and COPD are both associated with a higher rate of PPCs post lung cancer resection. COPD, independent of smoking status, is also associated with an increased overall post-operative complication rate and length of hospital stay. An emphasis on COPD treatment optimisation, rather than smoking cessation in isolation, may help improve postoperative outcomes. © 2022 Jeganathan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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