3,621 research outputs found

    Some Problems in Blood Testing and Grouping

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    Contemplating Mindfulness at Work: An Integrative Review

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    Mindfulness research activity is surging within organizational science. Emerging evidence across multiple fields suggests that mindfulness is fundamentally connected to many aspects of workplace functioning, but this knowledge base has not been systematically integrated to date. This review coalesces the burgeoning body of mindfulness scholarship into a framework to guide mainstream management research investigating a broad range of constructs. The framework identifies how mindfulness influences attention, with downstream effects on functional domains of cognition, emotion, behavior, and physiology. Ultimately, these domains impact key workplace outcomes, including performance, relationships, and well-being. Consideration of the evidence on mindfulness at work stimulates important questions and challenges key assumptions within management science, generating an agenda for future research

    K2 Variable Catalogue: Variable Stars and Eclipsing Binaries in K2 Campaigns 1 and 0

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    We have created a catalogue of variable stars found from a search of the publicly available K2 mission data from Campaigns 1 and 0. This catalogue provides the identifiers of 8395 variable stars, including 199 candidate eclipsing binaries with periods up to 60d and 3871 periodic or quasi-periodic objects, with periods up to 20d for Campaign 1 and 15d for Campaign 0. Lightcurves are extracted and detrended from the available data. These are searched using a combination of algorithmic and human classification, leading to a classifier for each object as an eclipsing binary, sinusoidal periodic, quasi periodic, or aperiodic variable. The source of the variability is not identified, but could arise in the non-eclipsing binary cases from pulsation or stellar activity. Each object is cross-matched against variable star related guest observer proposals to the K2 mission, which specifies the variable type in some cases. The detrended lightcurves are also compared to lightcurves currently publicly available. The resulting catalogue is made available online via the MAST archive at https://archive.stsci.edu/prepds/k2varcat/, and gives the ID, type, period, semi-amplitude and range of the variation seen. We also make available the detrended lightcurves for each object.Comment: Accepted by A&A. 6 pages, 6 figures. Catalogue and lightcurves are available online via MAST at https://archive.stsci.edu/prepds/k2varcat

    K2 Variable Catalogue II: Machine Learning Classification of Variable Stars and Eclipsing Binaries in K2 Fields 0-4

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    We are entering an era of unprecedented quantities of data from current and planned survey telescopes. To maximise the potential of such surveys, automated data analysis techniques are required. Here we implement a new methodology for variable star classification, through the combination of Kohonen Self Organising Maps (SOM, an unsupervised machine learning algorithm) and the more common Random Forest (RF) supervised machine learning technique. We apply this method to data from the K2 mission fields 0-4, finding 154 ab-type RR Lyraes (10 newly discovered), 377 Delta Scuti pulsators, 133 Gamma Doradus pulsators, 183 detached eclipsing binaries, 290 semi-detached or contact eclipsing binaries and 9399 other periodic (mostly spot-modulated) sources, once class significance cuts are taken into account. We present lightcurve features for all K2 stellar targets, including their three strongest detected frequencies, which can be used to study stellar rotation periods where the observed variability arises from spot modulation. The resulting catalogue of variable stars, classes, and associated data features are made available online. We publish our SOM code in Python as part of the open source PyMVPA package, which in combination with already available RF modules can be easily used to recreate the method.Comment: Accepted for publication in MNRAS, 16 pages, 13 figures. Updated with proof corrections. Full catalogue tables available at https://www2.warwick.ac.uk/fac/sci/physics/research/astro/people/armstrong/ or at the CD

    Langevin Simulation of Thermally Activated Magnetization Reversal in Nanoscale Pillars

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    Numerical solutions of the Landau-Lifshitz-Gilbert micromagnetic model incorporating thermal fluctuations and dipole-dipole interactions (calculated by the Fast Multipole Method) are presented for systems composed of nanoscale iron pillars of dimension 9 nm x 9 nm x 150 nm. Hysteresis loops generated under sinusoidally varying fields are obtained, while the coercive field is estimated to be 1979 ±\pm 14 Oe using linear field sweeps at T=0 K. Thermal effects are essential to the relaxation of magnetization trapped in a metastable orientation, such as happens after a rapid reversal of an external magnetic field less than the coercive value. The distribution of switching times is compared to a simple analytic theory that describes reversal with nucleation at the ends of the nanomagnets. Results are also presented for arrays of nanomagnets oriented perpendicular to a flat substrate. Even at a separation of 300 nm, where the field from neighboring pillars is only ∼\sim 1 Oe, the interactions have a significant effect on the switching of the magnets.Comment: 19 pages RevTeX, including 12 figures, clarified discussion of numerical technique

    Semiclassical Double-Pomeron Production of Glueballs and η′\eta'

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    A semiclassical theory of high energy scattering based on interrupted tunneling (instantons) or QCD sphaleron production has been recently developed to describe the growing hadronic cross section and properties of the soft Pomeron. In this work we address double-pomeron processes in this framework for the first time. We specifically derive the cross section for central production of parity even and odd clusters, scalar and pseudoscalar glueballs, and η′\eta' in parton-parton scattering at high energy. We show that the specific dependence of the production cross section on all its kinematical variables compares favorably with the UA8 data on inclusive cluster production, as well as the WA102 data on exclusive central production of scalar glueball and η′\eta', in double-pomeron exchange pppp scattering. The magnitude of the cross section and its dependece on kinematic variables is correct, explaining in particular a large deviation from the Pomeron factorization at cluster masses in the range MX<8M_X<8 GeV reported by UA8

    Prophylactic methylprednisolone to reduce inflammation and improve outcomes from one lung ventilation in children: a randomized clinical trial.

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    BACKGROUND: One lung ventilation (OLV) results in inflammatory and mechanical injury, leading to intraoperative and postoperative complications in children. No interventions have been studied in children to minimize such injury. OBJECTIVE: We hypothesized that a single 2-mg·kg(-1) dose of methylprednisolone given 45-60 min prior to lung collapse would minimize injury from OLV and improve physiological stability. METHODS: Twenty-eight children scheduled to undergo OLV were randomly assigned to receive 2 mg·kg(-1) methylprednisolone (MP) or normal saline (placebo group) prior to OLV. Anesthetic management was standardized, and data were collected for physiological stability (bronchospasm, respiratory resistance, and compliance). Plasma was assayed for inflammatory markers related to lung injury at timed intervals related to administration of methylprednisolone. RESULTS: Three children in the placebo group experienced clinically significant intraoperative and postoperative respiratory complications. Respiratory resistance was lower (P = 0.04) in the methylprednisolone group. Pro-inflammatory cytokine IL-6 was lower (P = 0.01), and anti-inflammatory cytokine IL-10 was higher (P = 0.001) in the methylprednisolone group. Tryptase, measured before and after OLV, was lower (P = 0.03) in the methylprednisolone group while increased levels of tryptase were seen in placebo group after OLV (did not achieve significance). There were no side effects observed that could be attributed to methylprednisolone in this study. CONCLUSIONS: Methylprednisolone at 2 mg·kg(-1) given as a single dose prior to OLV provides physiological stability to children undergoing OLV. In addition, methylprednisolone results in lower pro-inflammatory markers and higher anti-inflammatory markers in the children\u27s plasma
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