Secondary School Athletic Trainers’ Perceived Confidence In Providing Independent Medical Care Within Differing Healthcare Delivery Models

ABSTRACT Purpose: The aim of this study was to evaluate athletic trainers’ confidence and ability to deliver independent medical care in the secondary school setting. Methods: A cross-sectional survey design was used with open- and closed-ended questions using a tool that was modified from a previously validated tool used within the collegiate setting; the tool was adapted through content expert validation. Results: Athletic trainers perceived themselves as confident in providing independent medical care through the school district healthcare delivery model (n=109/121, 90%) more often than those functioning within the hospital/clinic outreach model (n=85/130, 65%). Conclusions: Despite not having nationalized legislation and having variable support structures in place, secondary school athletic trainers are confident in providing independent medical care even when their direct supervisor may not be a healthcare provider. This is contradictory to similar findings within the collegiate setting governed by National Collegiate Athletics Association legislation enforcing independent medical care

A γ\gamma-ray determination of the Universe's star-formation history

The light emitted by all galaxies over the history of the Universe produces the extragalactic background light (EBL) at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for $\gamma$ rays via photon-photon interactions, leaving an imprint in the spectra of distant $\gamma$-ray sources. We measure this attenuation using {739} active galaxies and one gamma-ray burst detected by the {\it Fermi} Large Area Telescope. This allows us to reconstruct the evolution of the EBL and determine the star-formation history of the Universe over 90\% of cosmic time. Our star-formation history is consistent with independent measurements from galaxy surveys, peaking at redshift $z\sim2$. Upper limits of the EBL at the epoch of re-ionization suggest a turnover in the abundance of faint galaxies at $z\sim 6$.Comment: Published on Science. This is the authors' version of the manuscrip

Background model systematics for the Fermi GeV excess

The possible gamma-ray excess in the inner Galaxy and the Galactic center (GC) suggested by Fermi-LAT observations has triggered a large number of studies. It has been interpreted as a variety of different phenomena such as a signal from WIMP dark matter annihilation, gamma-ray emission from a population of millisecond pulsars, or emission from cosmic rays injected in a sequence of burst-like events or continuously at the GC. We present the first comprehensive study of model systematics coming from the Galactic diffuse emission in the inner part of our Galaxy and their impact on the inferred properties of the excess emission at Galactic latitudes $2^\circ<|b|<20^\circ$ and 300 MeV to 500 GeV. We study both theoretical and empirical model systematics, which we deduce from a large range of Galactic diffuse emission models and a principal component analysis of residuals in numerous test regions along the Galactic plane. We show that the hypothesis of an extended spherical excess emission with a uniform energy spectrum is compatible with the Fermi-LAT data in our region of interest at $95\%$ CL. Assuming that this excess is the extended counterpart of the one seen in the inner few degrees of the Galaxy, we derive a lower limit of $10.0^\circ$ ($95\%$ CL) on its extension away from the GC. We show that, in light of the large correlated uncertainties that affect the subtraction of the Galactic diffuse emission in the relevant regions, the energy spectrum of the excess is equally compatible with both a simple broken power-law of break energy $2.1\pm0.2$ GeV, and with spectra predicted by the self-annihilation of dark matter, implying in the case of $\bar{b}b$ final states a dark matter mass of $49^{+6.4}_{-5.4}$ GeV.Comment: 65 pages, 28 figures, 7 table

Constraining Very Heavy Dark Matter Using Diffuse Backgrounds of Neutrinos and Cascaded Gamma Rays

We consider multi-messenger constraints on very heavy dark matter (VHDM) from recent Fermi gamma-ray and IceCube neutrino observations of isotropic background radiation. Fermi data on the diffuse gamma-ray background (DGB) shows a possible unexplained feature at very high energies (VHE), which we have called the "VHE Excess" relative to expectations for an attenuated power law extrapolated from lower energies. We show that VHDM could explain this excess, and that neutrino observations will be an important tool for testing this scenario. More conservatively, we derive new constraints on the properties of VHDM for masses of 10^3-10^10 GeV. These generic bounds follow from cosmic energy budget constraints for gamma rays and neutrinos that we developed elsewhere, based on detailed calculations of cosmic electromagnetic cascades and also neutrino detection rates. We show that combining both gamma-ray and neutrino data is essential for making the constraints on VHDM properties both strong and robust. In the lower mass range, our constraints on VHDM annihilation and decay are comparable to other results; however, our constraints continue to much higher masses, where they become relatively stronger.Comment: 33 pages, 21 figures, accepted for publication in JCA

Fundamental physics in space with the Fermi Gamma-ray Space Telescope

Successfully launched in June 2008, the Fermi Gamma-ray Space Telescope, formerly named GLAST, has been observing the high-energy gamma-ray sky with unprecedented sensitivity for more than two years, opening a new window on a wide variety of exotic astrophysical objects. This paper is a short overview of the main science highlights, aimed at non-specialists, with emphasis on those which are more directly connected with the study of fundamental physics---particularly the search for signals of new physics in the diffuse gamma-ray emission and in the cosmic radiation and the study of Gamma-Ray Burst as laboratories for testing possible violations of the Lorentz invariance.Comment: 12 pages, 7 figures, submitted for the proceedings of DICE 201

A bound on Planck-scale modifications of the energy-momentum composition rule from atomic interferometry

High sensitivity measurements in atomic spectroscopy were recently used in Amelino-Camelia et. al. to constraint the form of possible modifications of the energy-momentum dispersion relation resulting from Lorentz invariance violation (LIV). In this letter we show that the same data can be used successfully to set experimental bounds on deformations of the energy-momentum composition rule. Such modifications are natural in models of deformed Lorentz symmetry which are relevant in certain quantum gravity scenarios. We find the bound for the deformation parameter $\kappa$ to be a few orders of magnitude below the Planck scale and of the same magnitude as the next-to-leading order effect found in Amelino-Camelia et. al. We briefly discuss how it would be possible to distinguish between these two scenarios.Comment: 5 pages, some comments and references adde

Annihilation of NMSSM neutralinos in the Sun and neutrino telescope limits

We investigate neutralino dark matter in the framework of NMSSM performing a scan over its parameter space and calculating neutralino capture and annihilation rates in the Sun. We discuss the prospects of searches for neutralino dark matter in neutrino experiments depending on neutralino content and its main annihilation channel. We recalculate the upper limits on neutralino-proton elastic cross sections directly from neutrino telescopes upper bounds on annihilation rates in the Sun. This procedure has advantages as compared with corresponding recalcalations from the limits on muon flux, namely, it is independent on details of the experiment and the recalculation coefficients are universal for any kind of WIMP dark matter models. We derive 90% c.l. upper limits on neutralino-proton cross sections from the results of the Baksan Underground Scintillator Telescope.Comment: 28 pages, 16 figures, accepted for publication in JCAP, references adde