108 research outputs found

    Insulating and Conducting Phases of RbC60

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    Optical measurements were performed on thin films of Rbx_{x}C60_{60}, identified by X-ray diffraction as mostly x=1x=1 material. The samples were subjected to various heat treatments, including quenching and slow cooling from 400K. The dramatic increase in the transmission of the quenched samples, and the relaxation towards the transmission observed in slow cooled samples provides direct evidence for the existence of a metastable insulating phase. Slow cooling results in a phase transition between two electrically conducting phases.Comment: Minor revisions. Submitted to PRB, RevTeX 3.0 file, 2 postscript figures included, ir_dop

    Infant Attentional Behaviors Are Associated with ADHD Symptomatology and Executive Function in Early Childhood

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    Objective: We explored associations between infant attentional behaviors as measured by the First Year Inventory (FYIv2.0) and dimensional ratings of ADHD symptomatology and executive function (EF) in early childhood. Methods: This study included parents (N = 229) who filled out the FYIv2.0 when their children were 12 months of age. When children were approximately 54 months (4.5 years) of age, parents completed reports of children’s ADHD symptomatology and EF abilities. Correlation and regression analyses were conducted among measures. Results: We found significant associations among the variables of interest, both cross-sectionally and longitudinally, as well as gender differences. Notably, non-social sensory attention (NSA) was significantly related to 54-month ADHD symptom severity. All three 12-month attention variables were significantly related to 54-month EF. Conclusion: Results suggest that infant attentional behaviors predict later ADHD-related behaviors in early childhood. Future research should explore associations using laboratory-based measures and could inform early intervention efforts

    Customer emotions in service failure and recovery encounters

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    Emotions play a significant role in the workplace, and considerable attention has been given to the study of employee emotions. Customers also play a central function in organizations, but much less is known about customer emotions. This chapter reviews the growing literature on customer emotions in employee–customer interfaces with a focus on service failure and recovery encounters, where emotions are heightened. It highlights emerging themes and key findings, addresses the measurement, modeling, and management of customer emotions, and identifies future research streams. Attention is given to emotional contagion, relationships between affective and cognitive processes, customer anger, customer rage, and individual differences

    A Measurement of the Proton Structure Function F ⁣2(x,Q2)F_{\!2}(x,Q^2)

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    A measurement of the proton structure function F ⁣2(x,Q2)F_{\!2}(x,Q^2) is reported for momentum transfer squared Q2Q^2 between 4.5 GeV2GeV^2 and 1600 GeV2GeV^2 and for Bjorken xx between 1.81041.8\cdot10^{-4} and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that F ⁣2F_{\!2} increases significantly with decreasing xx, confirming our previous measurement made with one tenth of the data available in this analysis. The Q2Q^2 dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the "diffractive" contribution to F ⁣2F_{\!2}.Comment: 32 pages, ps, appended as compressed, uuencoded fil

    All-sky search for long-duration gravitational wave transients with initial LIGO

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    We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

    All-sky search for long-duration gravitational wave transients with initial LIGO

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    We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

    Distinct germline genetic susceptibility profiles identified for common non-Hodgkin lymphoma subtypes

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    Lymphoma risk is elevated for relatives with common non-Hodgkin lymphoma (NHL) subtypes, suggesting shared genetic susceptibility across subtypes. To evaluate the extent of mutual heritability among NHL subtypes and discover novel loci shared among subtypes, we analyzed data from eight genome-wide association studies within the InterLymph Consortium, including 10,629 cases and 9505 controls. We utilized Association analysis based on SubSETs (ASSET) to discover loci for subsets of NHL subtypes and evaluated shared heritability across the genome using Genome-wide Complex Trait Analysis (GCTA) and polygenic risk scores. We discovered 17 genome-wide significant loci (P < 5 × 10−8) for subsets of NHL subtypes, including a novel locus at 10q23.33 (HHEX) (P = 3.27 × 10−9). Most subset associations were driven primarily by only one subtype. Genome-wide genetic correlations between pairs of subtypes varied broadly from 0.20 to 0.86, suggesting substantial heterogeneity in the extent of shared heritability among subtypes. Polygenic risk score analyses of established loci for different lymphoid malignancies identified strong associations with some NHL subtypes (P < 5 × 10−8), but weak or null associations with others. Although our analyses suggest partially shared heritability and biological pathways, they reveal substantial heterogeneity among NHL subtypes with each having its own distinct germline genetic architecture

    PI3K signalling in inflammation

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    AbstractPI3Ks regulate several key events in the inflammatory response to damage and infection. There are four Class I PI3K isoforms (PI3Kα,β,γ,δ), three Class II PI3K isoforms (PI3KC2α, C2β, C2γ) and a single Class III PI3K. The four Class I isoforms synthesise the phospholipid ‘PIP3’. PIP3 is a ‘second messenger’ used by many different cell surface receptors to control cell movement, growth, survival and differentiation. These four isoforms have overlapping functions but each is adapted to receive efficient stimulation by particular receptor sub-types. PI3Kγ is highly expressed in leukocytes and plays a particularly important role in chemokine-mediated recruitment and activation of innate immune cells at sites of inflammation. PI3Kδ is also highly expressed in leukocytes and plays a key role in antigen receptor and cytokine-mediated B and T cell development, differentiation and function. Class III PI3K synthesises the phospholipid PI3P, which regulates endosome-lysosome trafficking and the induction of autophagy, pathways involved in pathogen killing, antigen processing and immune cell survival. Much less is known about the function of Class II PI3Ks, but emerging evidence indicates they can synthesise PI3P and PI34P2 and are involved in the regulation of endocytosis.The creation of genetically-modified mice with altered PI3K signalling, together with the development of isoform-selective, small-molecule PI3K inhibitors, has allowed the evaluation of the individual roles of Class I PI3K isoforms in several mouse models of chronic inflammation. Selective inhibition of PI3Kδ, γ or β has each been shown to reduce the severity of inflammation in one or more models of autoimmune disease, respiratory disease or allergic inflammation, with dual γ/δ or β/δ inhibition generally proving more effective. The inhibition of Class I PI3Ks may therefore offer a therapeutic opportunity to treat non-resolving inflammatory pathologies in humans. This article is part of a Special Issue entitled Phosphoinositides
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