1,455 research outputs found

    Wind tunnel testing of low-drag airfoils

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    Results are presented for the measured performance recently obtained on several airfoil concepts designed to achieve low drag by maintaining extensive regions of laminar flow without compromising high-lift performance. The wind tunnel results extend from subsonic to transonic speeds and include boundary-layer control through shaping and suction. The research was conducted in the NASA Langley 8-Ft Transonic Pressure Tunnel (TPT) and Low Turbulence Pressure Tunnel (LTPT) which have been developed for testing such low-drag airfoils. Emphasis is placed on identifying some of the major factors influencing the anticipated performance of low-drag airfoils

    Research and Critical Thinking : An Important Link for Exercise Science Students Transitioning to Physical Therapy

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    Int J Exerc Sci 5(2) : 93-96, 2012. Critical thinking skills are increasingly necessary for success in professional health care careers. Changes in the contemporary healthcare system in the United States arguably make these critical thinking skills more important than they have ever been, as clinicians are required on a daily basis to evaluate multiple bits of information about patients with multiple-systemic health concerns and make appropriate treatment decisions based on this information. We believe the IJES, with its emphasis on engaging undergraduate and graduate students in research and scholarly activity, is a valuable resource for promoting the higher-order critical thinking skills necessary for preparing exercise science students with an interest in professional healthcare careers such as physical therapy

    Neurophysiology

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    Contains research objectives and summary of research on sixteen research projects.National Institutes of Health (Grant 5 TO1 EY00090-03)National Institutes of Health (Grant 3 RO1 EY01149-03S1)Bell Laboratories (Grant)National Institutes of Health (Grant 5 RO1 NS12307-02)National Institutes of Health (Grant K04 NS00010

    Neurophysiology

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    Contains research objectives and summary of research on seventeen research projects and reports on four research projects.National Institutes of Health (Grant 5 TOl EY00090-02)Bell Telephone Laboratories, Inc. (Grant)National Institutes of Health (Grant 5 ROI EY01149-03)National Institutes of Health (Grant NS 12307-01)National Institutes of Health (Grant 1 K04 NS00010

    Identifying the genetic basis of antigenic change in influenza A(H1N1)

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    Determining phenotype from genetic data is a fundamental challenge. Influenza A viruses undergo rapid antigenic drift and identification of emerging antigenic variants is critical to the vaccine selection process. Using former seasonal influenza A(H1N1) viruses, hemagglutinin sequence and corresponding antigenic data were analyzed in combination with 3-D structural information. We attributed variation in hemagglutination inhibition to individual amino acid substitutions and quantified their antigenic impact, validating a subset experimentally using reverse genetics. Substitutions identified as low-impact were shown to be a critical component of influenza antigenic evolution and by including these, as well as the high-impact substitutions often focused on, the accuracy of predicting antigenic phenotypes of emerging viruses from genotype was doubled. The ability to quantify the phenotypic impact of specific amino acid substitutions should help refine techniques that predict the fitness and evolutionary success of variant viruses, leading to stronger theoretical foundations for selection of candidate vaccine viruses

    Neurophysiology

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    Contains reports on twenty research projects.Bell Laboratories (Grant)National Institutes of Health (Grant 5 R01 EY01149-03S2)National Institutes of Health (Grant 5 TO1 EY00090-04)National Institutes of Health (Grant 5 RO1 NS12307-03)National Institutes of Health (Grant K04 NS00010)National Multiple Sclerosis Society (Grant RG-1133-A-1)Health Sciences Fund (Grant 78-10

    Lack of Effect of Induction of Hypothermia after Acute Brain Injury

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    Background Induction of hypothermia in patients with brain injury was shown to improve outcomes in small clinical studies, but the results were not definitive. To study this issue, we conducted a multicenter trial comparing the effects of hypothermia with those of normothermia in patients with acute brain injury. Methods The study subjects were 392 patients 16 to 65 years of age with coma after sustaining closed head injuries who were randomly assigned to be treated with hypothermia (body temperature, 33°C), which was initiated within 6 hours after injury and maintained for 48 hours by means of surface cooling, or normothermia. All patients otherwise received standard treatment. The primary outcome measure was functional status six months after the injury. Results The mean age of the patients and the type and severity of injury in the two treatment groups were similar. The mean (±SD) time from injury to randomization was 4.3±1.1 hours in the hypothermia group and 4.1±1.2 hours in the normothermia group, and the mean time from injury to the achievement of the target temperature of 33°C in the hypothermia group was 8.4±3.0 hours. The outcome was poor (defined as severe disability, a vegetative state, or death) in 57 percent of the patients in both groups. Mortality was 28 percent in the hypothermia group and 27 percent in the normothermia group (P=0.79). The patients in the hypothermia group had more hospital days with complications than the patients in the normothermia group. Fewer patients in the hypothermia group had high intracranial pressure than in the normothermia group. Conclusions Treatment with hypothermia, with the body temperature reaching 33°C within eight hours after injury, is not effective in improving outcomes in patients with severe brain injury. (N Engl J Med 2001; 344:556-63.

    Two‐nucleon processes in pion‐induced double charge exchange in 4He: A coincidence measurement of the 4He(π+,π− p)3p reaction

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    Inclusive measurements of pion double‐charge‐exchange in 3He[1] and 4He[2] in the Δ(1232) resonance region suggest the dominance of a two‐step sequential single‐charge‐exchange mechanism involving quasi‐free nucleons. To investigate this reaction mechanism, we have observed protons in coincidence with the outgoing pion in π++4He→π−+4p at Tπ+=240 MeV. Pions were detected in a magnetic spectrometer at θπ−=32°, while protons were detected in a close‐packed array of plastic scintillator telescopes covering θp=67.5°–157.5° on the same side of the beam as the spectrometer, and θp=22.5°–157.5° on the opposite side. We will present preliminary results for the distributions in energy and angle of the coincident protons. © 1995 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87562/2/542_1.pd

    Geons with spin and charge

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    We construct new geon-type black holes in D>3 dimensions for Einstein's theory coupled to gauge fields. A static nondegenerate vacuum black hole has a geon quotient provided the spatial section admits a suitable discrete isometry, and an antisymmetric tensor field of rank 2 or D-2 with a pure F^2 action can be included by an appropriate (and in most cases nontrivial) choice of the field strength bundle. We find rotating geons as quotients of the Myers-Perry(-AdS) solution when D is odd and not equal to 7. For other D we show that such rotating geons, if they exist at all, cannot be continuously deformed to zero angular momentum. With a negative cosmological constant, we construct geons with angular momenta on a torus at the infinity. As an example of a nonabelian gauge field, we show that the D=4 spherically symmetric SU(2) black hole admits a geon version with a trivial gauge bundle. Various generalisations, including both black-brane geons and Yang-Mills theories with Chern-Simons terms, are briefly discussed.Comment: 26 pages, 1 figure. LaTeX with amssymb, amsmath. (v2: References and a figure added.

    Bartonella seropositivity in children with Henoch-Schonlein purpura

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    BACKGROUND: An association between Henoch-Schonlein purpura (HSP) and seropositivity for Bartonella henselae (BH) has been described. The objective of this study was to see if such an association exists in northern Alberta. METHODS: Immunofluorescent antibody testing utilizing an antigen prepared from B. henselae was undertaken on sera from six children with current HSP, 22 children with remote HSP, and 28 controls that were matched for age. Blood from the six children with current HSP was analysed by polymerase chain reaction (PCR) assay with primers derived from the citrate synthase (gltA) gene for the detection of Bartonella DNA. RESULTS: The seropositivity rate for BH was 61% in cases versus 21% in controls (p < 0.03). The PCR assay was negative in all six current cases. CONCLUSION: There is an increased seropositivity rate for BH in children with HSP. However, it is not clear if infection with B. henselae or a related Bartonella species can result in HSP, or if the increased seropositivity is from non-specific or cross-reacting antibodies
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