678 research outputs found

    Validation of Phonon Physics in the CDMS Detector Monte Carlo

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    The SuperCDMS collaboration is a dark matter search effort aimed at detecting the scattering of WIMP dark matter from nuclei in cryogenic germanium targets. The CDMS Detector Monte Carlo (CDMS-DMC) is a simulation tool aimed at achieving a deeper understanding of the performance of the SuperCDMS detectors and aiding the dark matter search analysis. We present results from validation of the phonon physics described in the CDMS-DMC and outline work towards utilizing it in future WIMP search analyses.Comment: 6 Pages, 5 Figures, Proceedings of Low Temperature Detectors 14 Conferenc

    Outbreak of Rift Valley fever affecting veterinarians and farmers in South Africa, 2008

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    Background. During 2008, Rift Valley fever (RVF) virus re-emerged in South Africa as focal outbreaks in several provinces. Aims. To investigate an outbreak affecting cattle farmers and farm workers, and the staff and students of a veterinary school, assess the prevalence of infection during the outbreak, document the clinical presentation of cases, and identify potential risk factors. Methods. We conducted a cross-sectional serological survey of exposed veterinarians and farmers, who were examined to determine the presence of current or recent illness. Blood specimens were collected for virus isolation, nucleic acid detection and serology. A subset was interviewed using a standardised questionnaire to obtain data on recent exposures and risk factors for infection. Results. Of 53 participants potentially exposed to infected domestic ruminants, 15% had evidence of recent infection and 4% evidence of past exposure to the RVF virus. The prevalence of acute infection was 21% in veterinarians compared with 9% in farmers and farm workers. After a mean incubation period of 4.3 days, the most frequent symptoms experienced included myalgia (100%), headache (88%) and malaise (75%). No asymptomatic cases were identified. Transmission by direct contact with infected animals was the major risk factor in these professional groups. Performing animal autopsies was significantly associated with acute infection (risk ratio 16.3, 95% confidence interval 2.3 - 114.2). Conclusions. Increased risks associated with veterinary practices highlight a need for the use of personal protective equipment, and identify veterinarians as a primary target group for future vaccination

    Quasi-static penetration behavior of plain woven kenaf/aramid reinforced polyvinyl butyral hybrid laminates

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    Owing to the high cost of synthetic aramid fibers and the necessity for environmentally friendly alternatives, a portion of aramid was replaced by plain woven kenaf fiber, with different lay arrangements and thicknesses. The obtained hybrid composites with aramid and kenaf fibers were used to produce prototypes of army helmet shells. A hybrid composite material was produced using a hot press technique and comprises 19 layers of plain woven kenaf and aramid of various configurations and alternation. The behavior of this composite material on a quasi-static penetration test was studied and was found positive in terms of maximum load carried, energy absorbed in impact, and damage mechanisms. Consequently, a helmet armour was developed that was less costly and more readily available and that which could also be produced by reducing the potential harmful effects of petroleum products, without compromising the ballistic-resistant capability of the material

    Expressing coherence of musical perception in formal logic

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    Formal logic can be used for expressing certain aspects of musical coherence. In this paper, a framework is developed which aims at linking. expressions in the formal language to an underlying interpretation in terms of musical images and image transformations. Such an interpretation characterizes truth within a framework of spatio-temporal representations and perception-based musical information processing. The framework provides a way for defining a semantics for the coherence of musical perception

    Genome mapping and characterization of the Anopheles gambiae heterochromatin

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    <p>Abstract</p> <p>Background</p> <p>Heterochromatin plays an important role in chromosome function and gene regulation. Despite the availability of polytene chromosomes and genome sequence, the heterochromatin of the major malaria vector <it>Anopheles gambiae </it>has not been mapped and characterized.</p> <p>Results</p> <p>To determine the extent of heterochromatin within the <it>An. gambiae </it>genome, genes were physically mapped to the euchromatin-heterochromatin transition zone of polytene chromosomes. The study found that a minimum of 232 genes reside in 16.6 Mb of mapped heterochromatin. Gene ontology analysis revealed that heterochromatin is enriched in genes with DNA-binding and regulatory activities. Immunostaining of the <it>An. gambiae </it>chromosomes with antibodies against <it>Drosophila melanogaster </it>heterochromatin protein 1 (HP1) and the nuclear envelope protein lamin Dm<sub>0 </sub>identified the major invariable sites of the proteins' localization in all regions of pericentric heterochromatin, diffuse intercalary heterochromatin, and euchromatic region 9C of the 2R arm, but not in the compact intercalary heterochromatin. To better understand the molecular differences among chromatin types, novel Bayesian statistical models were developed to analyze genome features. The study found that heterochromatin and euchromatin differ in gene density and the coverage of retroelements and segmental duplications. The pericentric heterochromatin had the highest coverage of retroelements and tandem repeats, while intercalary heterochromatin was enriched with segmental duplications. We also provide evidence that the diffuse intercalary heterochromatin has a higher coverage of DNA transposable elements, minisatellites, and satellites than does the compact intercalary heterochromatin. The investigation of 42-Mb assembly of unmapped genomic scaffolds showed that it has molecular characteristics similar to cytologically mapped heterochromatin.</p> <p>Conclusions</p> <p>Our results demonstrate that <it>Anopheles </it>polytene chromosomes and whole-genome shotgun assembly render the mapping and characterization of a significant part of heterochromatic scaffolds a possibility. These results reveal the strong association between characteristics of the genome features and morphological types of chromatin. Initial analysis of the <it>An. gambiae </it>heterochromatin provides a framework for its functional characterization and comparative genomic analyses with other organisms.</p

    Monte Carlo Simulation of Massive Absorbers for Cryogenic Calorimeters

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    There is a growing interest in cryogenic calorimeters with macroscopic absorbers for applications such as dark matter direct detection and rare event search experiments. The physics of energy transport in calorimeters with absorber masses exceeding several grams is made complex by the anisotropic nature of the absorber crystals as well as the changing mean free paths as phonons decay to progressively lower energies. We present a Monte Carlo model capable of simulating anisotropic phonon transport in cryogenic crystals. We have initiated the validation process and discuss the level of agreement between our simulation and experimental results reported in the literature, focusing on heat pulse propagation in germanium. The simulation framework is implemented using Geant4, a toolkit originally developed for high-energy physics Monte Carlo simulations. Geant4 has also been used for nuclear and accelerator physics, and applications in medical and space sciences. We believe that our current work may open up new avenues for applications in material science and condensed matter physics.United States. Dept. of Energy (SLAC National Accelerator Laboratory. Contract DE-AC02-76SF00515

    The mechanical performance of sugar palm fibres (Ijuk) reinforced phenolic composites

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    Sugar palm fibres are one of the natural fibres which have many features and need further study to understand their properties. The aim of this work is to investigate the flexural, compressive and impact properties of sugar palm fibres reinforced phenolic composites. Sugar palm fibres were used as a filler (particle size 150 μm) and with loading of 0, 10, 20, 30, and 40 vol.%. The fibres were treated by sea water and then fabricated into composites by hot press technique. Flexural, compressive, and impact tests were carried out as per ASTM D790, ASTM D695-08a, and ASTM D256 standards, respectively. Scanning electron microscopy (SEM) was used to investigate the morphology and the interfacial bonding of the fibres-matrix in composites. The results show that the mechanical properties of the composites improve with the incorporation of fibres. The composite of 30 vol.% particle loading exhibit optimum values which are 32.23 MPa, 61.66 MPa, and 4.12 kJ/m2 for flexural, compressive, and impact strength, respectively. This was because good compatibility of fibre-matrix bonding. Consequently, sugar palm fibre is one of the prospective fibres and could be used as a potential resource to reinforcement polymer composite

    The sulfa residue problem in swine

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    1 online resource (PDF, 2 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

    Analysis of the low-energy electron-recoil spectrum of the CDMS experiment

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    We report on the analysis of the low-energy electron-recoil spectrum from the CDMS II experiment using data with an exposure of 443.2 kg-days. The analysis provides details on the observed counting rate and possible background sources in the energy range of 2 - 8.5 keV. We find no significant excess in the counting rate above background, and compare this observation to the recent DAMA results. In the framework of a conversion of a dark matter particle into electromagnetic energy, our 90% confidence level upper limit of 0.246 events/kg/day at 3.15 keV is lower than the total rate above background observed by DAMA by 8.9σ\sigma. In absence of any specific particle physics model to provide the scaling in cross section between NaI and Ge, we assume a Z^2 scaling. With this assumption the observed rate in DAMA differs from the upper limit in CDMS by 6.8σ\sigma. Under the conservative assumption that the modulation amplitude is 6% of the total rate we obtain upper limits on the modulation amplitude a factor of ~2 less than observed by DAMA, constraining some possible interpretations of this modulation.Comment: 4 pages, 3 figure

    Improving psychological science: further thoughts, reflections and ways forward

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    Cogent Psychology is a pioneering and dynamic Open Access journal for the psychology community, publishing original research, reviews, and replications that span the full spectrum of psychological inquiry. In 2021, it relaunched with a new Editor-in-Chief and Section Editors with an exciting vision to combine open access publishing with open research practices. As such, the journal welcomes traditional and new article formats, including Registered Reports, Brief Replication Reports, Review Articles, and Brief Reports. This broader range of formats is designed to reflect the evolving nature of psychological research and open science approaches. To the best of our knowledge, no other psychology journal offers such a distinctive combination of article publishing formats. Moreover, we welcome submissions in nine key areas of psychological science: Clinical Psychology, Cognitive & Experimental Psychology, Developmental Psychology, Educational Psychology, Health Psychology, Neuropsychology, Personality & Individual Differences, Social Psychology and Work, Industrial & Organisational Psychology
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