49 research outputs found

    Event-based processing of neutron scattering data at the Spallation Neutron Source

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    The Spallation Neutron Source at Oak Ridge National Laboratory, USA, ushered in a new era of neutron scattering experiments through the use of event-based data. Tagging each neutron event allows pump–probe experiments, measurements with a parameter asynchronous to the source, measurements with continuously varying parameters and novel ways of testing instrument components. This contribution will focus on a few examples. A pulsed magnet has been used to study diffraction under extreme fields. Continuous ramping of temperature is becoming standard on the POWGEN diffractometer. Battery degradation and phase transformations under heat and stress are often studied on the VULCAN diffractometer. Supercooled Al2O3 was studied on NOMAD. A study of a metallic glass through its glass transition was performed on the ARCS spectrometer, and the effect of source variation on chopper stability was studied for the SEQUOIA spectrometer. Besides a summary of these examples, an overview is provided of the hardware and software advances to enable these and many other event-based measurements

    Event-based processing of neutron scattering data at the Spallation Neutron Source

    Get PDF
    The Spallation Neutron Source at Oak Ridge National Laboratory, USA, ushered in a new era of neutron scattering experiments through the use of event-based data. Tagging each neutron event allows pump–probe experiments, measurements with a parameter asynchronous to the source, measurements with continuously varying parameters and novel ways of testing instrument components. This contribution will focus on a few examples. A pulsed magnet has been used to study diffraction under extreme fields. Continuous ramping of temperature is becoming standard on the POWGEN diffractometer. Battery degradation and phase transformations under heat and stress are often studied on the VULCAN diffractometer. Supercooled Al2O3 was studied on NOMAD. A study of a metallic glass through its glass transition was performed on the ARCS spectrometer, and the effect of source variation on chopper stability was studied for the SEQUOIA spectrometer. Besides a summary of these examples, an overview is provided of the hardware and software advances to enable these and many other event-based measurements

    Speaker- versus listener-oriented disfluency: A re-examination of arguments and assumptions from autism spectrum disorder

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    We re-evaluate conclusions about disfluency production in high-functioning forms of autism spectrum disorder (HFA). Previous studies examined individuals with HFA to address a theoretical question regarding speaker- and listener-oriented disfluencies. Individuals with HFA tend to be self-centric and have poor pragmatic language skills, and should be less likely to produce listener-oriented disfluency. However, previous studies did not account for individual differences variables that affect disfluency. We show that both matched and unmatched controls produce fewer repairs than individuals with HFA. For silent pauses, there was no difference between matched controls and HFA, but both groups produced more than unmatched controls. These results identify limitations in prior research and shed light on the relationship between autism spectrum disorders and disfluent speech

    Neonatal Colonisation Expands a Specific Intestinal Antigen-Presenting Cell Subset Prior to CD4 T-Cell Expansion, without Altering T-Cell Repertoire

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    Interactions between the early-life colonising intestinal microbiota and the developing immune system are critical in determining the nature of immune responses in later life. Studies in neonatal animals in which this interaction can be examined are central to understanding the mechanisms by which the microbiota impacts on immune development and to developing therapies based on manipulation of the microbiome. The inbred piglet model represents a system that is comparable to human neonates and allows for control of the impact of maternal factors. Here we show that colonisation with a defined microbiota produces expansion of mucosal plasma cells and of T-lymphocytes without altering the repertoire of alpha beta T-cells in the intestine. Importantly, this is preceded by microbially-induced expansion of a signal regulatory protein α-positive (SIRPα+) antigen-presenting cell subset, whilst SIRPα−CD11R1+ antigen-presenting cells (APCs) are unaffected by colonisation. The central role of intestinal APCs in the induction and maintenance of mucosal immunity implicates SIRPα+ antigen-presenting cells as orchestrators of early-life mucosal immune development

    The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Introduction of Ophiobolus graminis into new polders and its decline

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    Articulatory duration in single-word speech production.

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