176,876 research outputs found

    Search for Eccentric Binary Neutron Star Mergers in the first and second observing runs of Advanced LIGO

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    We present a search for gravitational waves from merging binary neutron stars which have non-negligible eccentricity as they enter the LIGO observing band. We use the public Advanced LIGO data which covers the period from 2015 through 2017 and contains 164\sim164 days of LIGO-Hanford and LIGO-Livingston coincident observing time. The search was conducted using matched-filtering using the PyCBC toolkit. We find no significant binary neutron star candidates beyond GW170817, which has previously been reported by searches for binaries in circular orbits. We place a 90% upper limit of 1700\sim1700 mergers Gpc3Yr1\textrm{Gpc}^{-3} \textrm{Yr}^{-1} for eccentricities 0.43\lesssim 0.43 at a dominant-mode gravitational-wave frequency of 10 Hz. The absence of a detection with these data is consistent with theoretical predictions of eccentric binary neutron star merger rates. Using our measured rate we estimate the sensitive volume of future gravitational-wave detectors and compare this to theoretical rate predictions. We find that, in the absence of a prior detection, the rate limits set by six months of Cosmic Explorer observations would constrain all current plausible models of eccentric binary neutron star formation

    Phonographic neighbors, not orthographic neighbors, determine word naming latencies

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    The orthographic neighborhood size (N) of a word—the number of words that can be formed from that word by replacing one letter with another in its place—has been found to have facilitatory effects in word naming. The orthographic neighborhood hypothesis attributes this facilitation to interactive effects. A phonographic neighborhood hypothesis, in contrast, attributes the effect to lexical print-sound conversion. According to the phonographic neighborhood hypothesis, phonographic neighbors (words differing in one letter and one phoneme, e.g., stove and stone) should facilitate naming, and other orthographic neighbors (e.g., stove and shove) should not. The predictions of these two hypotheses are tested. Unique facilitatory phonographic N effects were found in four sets of word naming mega-study data, along with an absence of facilitatory orthographic N effects. These results implicate print-sound conversion—based on consistent phonology—in neighborhood effects rather than word-letter feedback

    Encontrando la Comida Saludable: Identifying Food Access Barriers for the Adams County, Pennsylvania Latino Community

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    Overwhelming research indicates that recent national trends in U.S. food systems have led to the increased prevalence of processed foods and associated diet-related diseases. The effects of unhealthy diets have been distributed unevenly across the country’s socioeconomic and ethnic groups. Certain socioeconomic and ethnic groups face greater geographic, financial and cultural barriers to healthy food access. In Adams County, Pennsylvania, Latinos comprise 5.6% of the population, making them the county’s largest minority group, yet little is known about the food access barriers they face. In this study, we used a combination of surveys and focus groups with Latino residents and personal interviews with community leaders to identify the geographic, financial, and cultural barriers to food access for the county’s Latino community. We found that, though geographic and financial barriers had little effect on the community’s access to healthy food, cultural barriers presented a significant obstacle that needs to be addressed. We hope this study will inform the Adams County Food Policy Council in proposing policy measures that address specific food access issues in the county

    Signalling C-Type Lectins in Antimicrobial Immunity

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    Funding: This work was funded by the Wellcome Trust, Medical Research Council and the University of Aberdeen. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    SSX MHD Plasma Wind Tunnel

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    A new turbulent plasma source at the Swarthmore Spheromak Experiment (SSX) facility is described. The MHD wind tunnel configuration employs a magnetized plasma gun to inject high-beta plasma into a large, well-instrumented, vacuum drift region. This provides unique laboratory conditions approaching that in the solar wind: there is no applied background magnetic field in the drift region and has no net axial magnetic flux; the plasma flow speed is on the order of the local sound speed (M ~ 1), so flow energy density is comparable to thermal energy density; and the ratio of thermal to magnetic pressure is of order unity (plasma β ~ 1) so thermal energy density is also comparable to magnetic energy density. Results presented here and referenced within demonstrate the new capabilities and show how the new platform is proving useful for fundamental plasma turbulence studies

    A laser Doppler velocimeter approach for near-wall three-dimensional turbulence measurements

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    A near-wall laser Doppler velocimeter approach is described that relies on a beam-turning probe which makes possible the direct measurement of the crossflow velocity at a grazing incident and the placement of optical components close to the flow region of interest regardless of test facility size. Other important elements of the approach are the use of digital frequency processing, an optically smooth measurement surface, and observation of the sensing volume at 90 degrees. The combination was found to dramatically reduce noise-in-signal effects caused by surface light scattering. Turbulent boundary-layer data to within 20 microns (y(sup+) approximately equal to 1) of the surface are presented which illustrate the potential of the approach
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