University of Texas at Arlington

About: University of Texas at Arlington is a education organization based out in Arlington, Texas, United States. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 11758 authors who have published 28598 publications receiving 801626 citations. The organization is also known as: UT Arlington & University of Texas-Arlington.

When are phylogenetic analyses misled by convergence? A case study in Texas cave salamanders.

Abstract: Convergence, i.e., similarity between organisms that is not the direct result of shared phylogenetic history (and that may instead result from independent adaptations to similar environments), is a fundamental issue that lies at the interface of systematics and evolutionary biology. Although convergence is often cited as an important problem in morphological phylogenetics, there have been few well-documented examples of strongly supported and misleading phylogenetic estimates that result from adaptive convergence in morphology. In this article, we propose criteria that can be used to infer whether or not a phylogenetic analysis has been misled by convergence. We then apply these criteria in a study of central Texas cave salamanders (genus Eurycea). Morphological characters (apparently related to cave-dwelling habitat use) support a clade uniting the species E. rathbuni and E. tridentifera, whereas mitochondrial DNA sequences and allozyme data show that these two species are not closely related. We suggest that a likely explanation for the paucity of examples of strongly misleading morphological convergence is that the conditions under which adaptive convergence is most likely to produce strongly misleading results are limited. Specifically, convergence is most likely to be problematic in groups (such as the central Texas Eurycea) in which most species are morphologically very similar and some of the species have invaded and adapted to a novel selective environment.

Search for High-energy Neutrinos from Binary Neutron Star Merger GW170817 with ANTARES, IceCube, and the Pierre Auger Observatory

Abstract: The Advanced LIGO and Advanced Virgo observatories recently discovered gravitational waves from a binary neutron star inspiral. A short gamma-ray burst (GRB) that followed the merger of this binary was also recorded by the Fermi Gamma-ray Burst Monitor (Fermi-GBM), and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), indicating particle acceleration by the source. The precise location of the event was determined by optical detections of emission following the merger. We searched for high-energy neutrinos from the merger in the GeV–EeV energy range using the Antares, IceCube, and Pierre Auger Observatories. No neutrinos directionally coincident with the source were detected within ±500 s around the merger time. Additionally, no MeV neutrino burst signal was detected coincident with the merger. We further carried out an extended search in the direction of the source for high-energy neutrinos within the 14 day period following the merger, but found no evidence of emission. We used these results to probe dissipation mechanisms in relativistic outflows driven by the binary neutron star merger. The non-detection is consistent with model predictions of short GRBs observed at a large off-axis angle.

Nurses’ Implementation of Guidelines for Ventilator-Associated Pneumonia From the Centers for Disease Control and Prevention

Abstract: • BACKGROUND Ventilator-associated pneumonia accounts for 47% of infections in patients in intensive care units. Adherence to the best nursing practices recommended in the 2003 guidelines for the prevention of ventilator-associated pneumonia from the Centers for Disease Control and Prevention should reduce the risk of ventilator-associated pneumonia. • OBJECTIVE To evaluate the extent to which nurses working in intensive care units implement best practices when managing adult patients receiving mechanical ventilation. • METHODS Nurses attending education seminars in the United States completed a 29-item questionnaire about the type and frequency of care provided. • RESULTS Twelve hundred nurses completed the questionnaire. Most (82%) reported compliance with hand-washing guidelines, 75% reported wearing gloves, half reported elevating the head of the bed, a third reported performing subglottic suctioning, and half reported having an oral care protocol in their hospital. Nurses in hospitals with an oral care protocol reported better compliance with hand washing and maintaining head-of-bed elevation, were more likely to regularly provide oral care, and were more familiar with rates of ventilator-associated pneumonia and the organisms involved than were nurses working in hospitals without such protocols. • CONCLUSIONS The guidelines for the prevention of ventilator-associated pneumonia from the Centers for Disease Control and Prevention are not consistently or uniformly implemented. Practices of nurses employed in hospitals with oral care protocols are more often congruent with the guidelines than are practices of nurses employed in hospitals without such protocols. Significant reductions in rates of ventilatorassociated pneumonia may be achieved by broader implementation of oral care protocols. (American Journal of Critical Care. 2007;16:28-38)

Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using 4.7 fb − 1 of s = 7 TeV proton-proton collision data

Abstract: A search for squarks and gluinos in final states containing jets, missing transverse momentum and no high-p(T) electrons or muons is presented. The data represent the complete sample recorded in 2011 by the ATLAS experiment in 7 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 4.7 fb(-1). No excess above the Standard Model background expectation is observed. Gluino masses below 860 GeV and squark masses below 1320 GeV are excluded at the 95% confidence level in simplified models containing only squarks of the first two generations, a gluino octet and a massless neutralino, for squark or gluino masses below 2 TeV, respectively. Squarks and gluinos with equal masses below 1410 GeV are excluded. In minimal supergravity/constrained minimal supersymmetric Standard Model models with tan beta = 10, A(0) = 0 and mu > 0, squarks and gluinos of equal mass are excluded for masses below 1360 GeV. Constraints are also placed on the parameter space of supersymmetric models with compressed spectra. These limits considerably extend the region of supersymmetric parameter space excluded by previous measurements with the ATLAS detector.