6,680 research outputs found

    CPT Results from KTeV

    Get PDF
    I present several preliminary measurements from KTeV of the fundamental neutral kaon parameters, and their implications for CPT violation. A new limit is given on the sidereal time dependence of ϕ+\phi_{+-}. The results are based on data collected in 1996-97.Comment: 10 pages, 5 figures, Contribution to the CPT01 Conference, Bloomington, Indiana, August 2001. V. A. Kostelecky organize

    Quantized Thermoelectric Hall Effect Induces Giant Power Factor in a Topological Semimetal

    Get PDF
    Thermoelectrics are promising by directly generating electricity from waste heat. However, (sub-)room-temperature thermoelectrics have been a long-standing challenge due to vanishing electronic entropy at low temperatures. Topological materials offer a new avenue for energy harvesting applications. Recent theories predicted that topological semimetals at the quantum limit can lead to a large, non-saturating thermopower and a quantized thermoelectric Hall conductivity approaching a universal value. Here, we experimentally demonstrate the non-saturating thermopower and quantized thermoelectric Hall effect in the topological Weyl semimetal (WSM) tantalum phosphide (TaP). An ultrahigh longitudinal thermopower Sxx= 1.1x10^3 muV/K and giant power factor ~525 muW/cm/K^2 are observed at ~40K, which is largely attributed to the quantized thermoelectric Hall effect. Our work highlights the unique quantized thermoelectric Hall effect realized in a WSM toward low-temperature energy harvesting applications.Comment: 54 pages total, 5 main figures + 22 supplementary figures. To appear in Nature Communications (2020

    Automated electronic medical record sepsis detection in the emergency department

    Get PDF
    Background. While often first treated in the emergency department (ED), identification of sepsis is difficult. Electronic medical record (EMR) clinical decision tools offer a novel strategy for identifying patients with sepsis. The objective of this study was to test the accuracy of an EMR-based, automated sepsis identification system.Methods. We tested an EMR-based sepsis identification tool at a major academic, urban ED with 64,000 annual visits. The EMR system collected vital sign and laboratory test information on all ED patients, triggering a “sepsis alert” for those with ≥2 SIRS (systemic inflammatory response syndrome) criteria (fever, tachycardia, tachypnea, leukocytosis) plus ≥1 major organ dysfunction (SBP ≤ 90 mm Hg, lactic acid ≥2.0 mg/dL). We confirmed the presence of sepsis through manual review of physician, nursing, and laboratory records. We also reviewed a random selection of ED cases that did not trigger a sepsis alert. We evaluated the diagnostic accuracy of the sepsis identification tool.Results. From January 1 through March 31, 2012, there were 795 automated sepsis alerts. We randomly selected 300 cases without a sepsis alert from the same period. The true prevalence of sepsis was 355/795 (44.7%) among alerts and 0/300 (0%) among non-alerts. The positive predictive value of the sepsis alert was 44.7% (95% CI [41.2–48.2%]). Pneumonia and respiratory infections (38%) and urinary tract infection (32.7%) were the most common infections among the 355 patients with true sepsis (true positives). Among false-positive sepsis alerts, the most common medical conditions were gastrointestinal (26.1%), traumatic (25.7%), and cardiovascular (20.0%) conditions. Rates of hospital admission were: true-positive sepsis alert 91.0%, false-positive alert 83.0%, no sepsis alert 5.7%.Conclusions. This ED EMR-based automated sepsis identification system was able to detect cases with sepsis. Automated EMR-based detection may provide a viable strategy for identifying sepsis in the ED

    Observing the Evolution of the Universe

    Full text link
    How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed measurements one may address everything from the physics of the birth of the universe to the history of star formation and the process by which galaxies formed. One may in addition track the evolution of the dark energy and discover the net neutrino mass. We are at the dawn of a new era in which hundreds of square degrees of sky can be mapped with arcminute resolution and sensitivities measured in microKelvin. Acquiring these data requires the use of special purpose telescopes such as the Atacama Cosmology Telescope (ACT), located in Chile, and the South Pole Telescope (SPT). These new telescopes are outfitted with a new generation of custom mm-wave kilo-pixel arrays. Additional instruments are in the planning stages.Comment: Science White Paper submitted to the US Astro2010 Decadal Survey. Full list of 177 author available at http://cmbpol.uchicago.ed

    Search for the Higgs boson in lepton, tau and jets final states

    Get PDF
    We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with two or more jets using 9.7 fb^{-1} of Run II Fermilab Tevatron Collider data collected with the D0 detector. The analysis is sensitive to Higgs boson production via gluon fusion, associated vector boson production, and vector boson fusion, followed by the Higgs boson decay to tau lepton pairs or to W boson pairs. The ratios of 95% C.L. upper limits on the cross section times branching ratio to those predicted by the standard model are obtained for orthogonal subsamples that are enriched in either H -> tau tau decays or H -> WW decays, and for the combination of these subsample limits. The observed and expected limit ratios for the combined subsamples at a Higgs boson mass of 125 GeV are 11.3 and 9.0 respectively

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

    Get PDF
    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

    Get PDF
    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Influence of syllable-coda voicing on the acoustic properties of syllable-onset /l/ in English

    No full text
    International audienceProperties of syllable onset /l/ that depend on the voicing of the syllable coda were measured for four speakers, representing different nonrhotic British English accents that differ in their phonetic realization of onset /l/ and in their system of phonological contrast involving onset /l/ and /r/. Onset /l/ was longer before voiced than voiceless codas for all four speakers, and darker for two of them as measured by lower F2 frequency, and for these two and one other as measured by spectral center of gravity (COG). There were no coda-dependent differences in f0 in the /l/, and F1 frequency differed only for the fourth speaker. The vowel was also longer for all four speakers when the coda was voiced (as expected), while F1 was lower and F2 normally higher. One speaker provided data with fricative or affricate onsets: fricated segments were longer before voiced codas, but no coda-dependent COG differences were found. At least when the onset includes /l/, phonological voicing of the coda seems to be reflected in complex acousticphonetic properties distributed across the whole syllable, some properties being localized, others not. We describe these properties as variations in a brightsomber dimension. In most accents, when the coda is voiceless, the syllable is relatively bright: small proportions of periodic energy which is relatively high frequency at the syllable edges, and a high proportion of silence or aperiodic energy. When the coda is voiced, the syllable is relatively somber: a high proportion of periodic energy which is relatively low frequency at the syllable edges, and relatively small amounts of silence and aperiodic energy. Other accents use other combinations, dependent on the phonetic and phonological properties of liquids in the particular accent. The association of onset darkness and coda voicing does not seem to be ascribable to anticipatory coarticulation of features essential to voicing itself; this observation provides support for nonsegmental models of speech perception in which fine phonetic detail is mapped directly to linguistic structure without reference to phoneme-sized segments
    corecore