546 research outputs found

    Measurement of Coherent Elastic Neutrino-Nucleus Scattering from reactor antineutrinos

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    The 96.4 day exposure of a 3 kg ultra-low noise germanium detector to the high flux of antineutrinos from a power nuclear reactor is described. A very strong preference (p<1.2×103p<1.2\times10^{-3}) for the presence of a coherent elastic neutrino-nucleus scattering (CEν\nuNS) component in the data is found, when compared to a background-only model. No such effect is visible in 25 days of operation during reactor outages. The best-fit CEν\nuNS signal is in good agreement with expectations based on a recent characterization of germanium response to sub-keV nuclear recoils. Deviations of order 60\% from the Standard Model CEν\nuNS prediction can be excluded using present data. Standing uncertainties in models of germanium quenching factor, neutrino energy spectrum, and background are examined.Comment: 6 pages, 5 figures. Data release and additional information in ancillary file

    Redefining genomic privacy: trust and empowerment

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    Fulfilling the promise of the genetic revolution requires the analysis of large datasets containing information from thousands to millions of participants. However, sharing human genomic data requires protecting subjects from potential harm. Current models rely on de-identification techniques in which privacy versus data utility becomes a zero-sum game. Instead, we propose the use of trust-enabling techniques to create a solution in which researchers and participants both win. To do so we introduce three principles that facilitate trust in genetic research and outline one possible framework built upon those principles. Our hope is that such trust-centric frameworks provide a sustainable solution that reconciles genetic privacy with data sharing and facilitates genetic research

    Experimental constraints on a dark matter origin for the DAMA annual modulation effect

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    A claim for evidence of dark matter interactions in the DAMA experiment has been recently reinforced. We employ a new type of germanium detector to conclusively rule out a standard isothermal galactic halo of Weakly Interacting Massive Particles (WIMPs) as the explanation for the annual modulation effect leading to the claim. Bounds are similarly imposed on a suggestion that dark pseudoscalars mightlead to the effect. We describe the sensitivity to light dark matter particles achievable with our device, in particular to Next-to-Minimal Supersymmetric Model candidates.Comment: v4: introduces recent results from arXiv:0807.3279 and arXiv:0807.2926. Sensitivity to pseudoscalars is revised in light of the first. Discussion on the subject adde

    Characterization of a photosystem II reaction center complex isolated by exposure of PSII membranes to a non-ionic detergent and high concentrations of NaCl

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    A highly resolved PSII reaction center complex has been prepared by exposure of PSII membranes to the detergent octylglucopyranoside at elevated ionic strengths; oxygen evolution activity is about 1,000 μmoles O 2 /hr/mg Chl in the presence of CaCl 2 . A Mn quantitation and a kinetic study of Z, the donor to P 680 , reveals that on a Chl basis this new preparation shows an almost four-fold enrichment in Mn and the electron transport components of PSII.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43532/1/11120_2004_Article_BF00118314.pd

    Portable, field-based neuroimaging using high-density diffuse optical tomography

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    Behavioral and cognitive tests in individuals who were malnourished as children have revealed malnutrition-related deficits that persist throughout the lifespan. These findings have motivated recent neuroimaging investigations that use highly portable functional near-infrared spectroscopy (fNIRS) instruments to meet the demands of brain imaging experiments in low-resource environments and enable longitudinal investigations of brain function in the context of long-term malnutrition. However, recent studies in healthy subjects have demonstrated that high-density diffuse optical tomography (HD-DOT) can significantly improve image quality over that obtained with sparse fNIRS imaging arrays. In studies of both task activations and resting state functional connectivity, HD-DOT is beginning to approach the data quality of fMRI for superficial cortical regions. In this work, we developed a customized HD-DOT system for use in malnutrition studies in Cali, Colombia. Our results evaluate the performance of the HD-DOT instrument for assessing brain function in a cohort of malnourished children. In addition to demonstrating portability and wearability, we show the HD-DOT instrument\u27s sensitivity to distributed brain responses using a sensory processing task and measurements of homotopic functional connectivity. Task-evoked responses to the passive word listening task produce activations localized to bilateral superior temporal gyrus, replicating previously published work using this paradigm. Evaluating this localization performance across sparse and dense reconstruction schemes indicates that greater localization consistency is associated with a dense array of overlapping optical measurements. These results provide a foundation for additional avenues of investigation, including identifying and characterizing a child\u27s individual malnutrition burden and eventually contributing to intervention development
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