155 research outputs found

    search.bioPreprint: A discovery tool for cutting edge, preprint biomedical research articles

    Get PDF
    The time it takes for a completed manuscript to be published traditionally can be extremely lengthy. Article publication delay, which occurs in part due to constraints associated with peer review, can prevent the timely dissemination of critical and actionable data associated with new information on rare diseases or developing health concerns such as Zika virus. Preprint servers are open access online repositories housing preprint research articles that enable authors (1) to make their research immediately and freely available and (2) to receive commentary and peer review prior to journal submission. There is a growing movement of preprint advocates aiming to change the current journal publication and peer review system, proposing that preprints catalyze biomedical discovery, support career advancement, and improve scientific communication. While the number of articles submitted to and hosted by preprint servers are gradually increasing, there has been no simple way to identify biomedical research published in a preprint format, as they are not typically indexed and are only discoverable by directly searching the specific preprint server websites. To address this issue, we created a search engine that quickly compiles preprints from disparate host repositories and provides a one-stop search solution. Additionally, we developed a web application that bolsters the discovery of preprints by enabling each and every word or phrase appearing on any web site to be integrated with articles from preprint servers. This tool, search.bioPreprint, is publicly available at http://www.hsls.pitt.edu/resources/preprint

    NDM-505: DEVELOPMENT OF THE ASCE/SEI STANDARD FOR THE ESTIMATION OF TORNADO WIND SPEEDS

    Get PDF
    Development of the new ASCE/SEI consensus standard for wind speed estimation in tornadoes began in 2014 and is currently underway. The intent of the new standard is to standardize the methods used to estimate the wind speeds in tornadoes including improvements and expansions for the damaged-based Enhanced Fujita Scale (EF Scale), with potential to extend the scope of the standard to include other windstorms. The standard will include sections on the EF Scale, radar measurements, tree fall pattern analysis, data archives, forensic engineering analysis, in-situ measurements (anemometry), and remote-sensing applications. Users of the standard will include wind, structural and forensic engineers, meteorologists, climatologists, forest biologists, risk analysts, hazards modellers, emergency managers, building and infrastructure designers, the insurance industry, and the media. The standard is intended for adoption by the National Weather Service and for use by storm study teams and researchers as a guide for conducting storm surveys and analysis of storm data. Development of the standard highlights the current state-of-the art in wind speed estimation and also identifies areas where new research is needed. Development of the standard will include a public ballot period. The standard is scheduled to be completed in 2019

    Vestibulo-oculomotor Function Following a Competitive Season Versus a Non-competitive Season in Collegiate Football Players

    Get PDF
    Introduction Background Football athletes experience a high number of head impacts during competitive play that do not cause immediate observable signs or symptoms. Research shows that exposure to repeated subconcussive impacts has a negative effect on the vestibulo-oculomotor (V-O) system and can result in long term neurologic dysfunction. Little is known about the ability of the V-O system to recover if an athlete is given an extended time away from subconcussive impacts. Purpose To investigate the difference in V-O function following a non-competitive (due to COVID-19) vs. a competitive season in cleared-to-play football players. Methods Participants 32 Division II football players from Concordia University, St. Paul ages 19-23. Data was collected in 2021 following a non-competitive season and in 2022 following a competitive season. V-O Tests Dynamic Visual Acuity (DVA) Near-Point Convergence (NPC) Results No statistically significant differences in V-O test results were found between the non-competitive and competitive season. Nearly 60% of the athletes had at least one positive V-O test after the competitive season. Conclusion Time away from subconcussive impacts due to a non-competitive season does not appear to have significantly influenced V-O function in collegiate football players. However, of concern is the large number of cleared-to-play athletes testing positive in at least one assessment tool. Clinical Relevance The vestibular system has the opportunity to recover, yet we are still unable to draw firm conclusions about the amount of time away from head impacts that is necessary for full recovery For many of our participants, a single season away from head impacts was not enough time to recover It is recommended that there be further investigation into time away from contact sports and return-to-play protocols in season

    Measurements of the Decay KLe+eγK_L \to e^+e^-\gamma

    Full text link
    The E799-II (KTeV) experiment at Fermilab has collected 83262 KLe+eγK_L \to e^+e^-\gamma events above a background of 79 events. We measure a decay width, normalized to the KLπ0π0πD0K_L \to \pi^0\pi^0\pi^0_D (\pi^0 \to \gamma\gamma, \pi^0 to \gamma\gamma, \pi^0_D \to e^+e^-\gamma) decay width, of Γ(\Gamma(K_L \to e^+e^-\gamma)/Γ(KLπ0π0πD0)=(1.3302±0.0046stat±0.0102syst)×103)/\Gamma(K_L \to \pi^0\pi^0\pi^0_D) = (1.3302 \pm 0.0046_{stat} \pm 0.0102_{syst}) \times 10^{-3}. We also measure parameters of two KLγγK_L \gamma^{\ast}\gamma form factor models. In the Bergstrom, Masso, and Singer (BMS) parametrization, we find \caks = -0.517 \pm 0.030_{stat} \pm 0.022_{syst}. We separately fit for the first parameter of the D'Ambrosio, Isidori, and Portoles (DIP) model and find \adip = -1.729 \pm 0.043_{stat} \pm 0.028_{syst}.Comment: 5 pages, 3 figures, submitted to PR

    Precise Measurements of Direct CP Violation, CPT Symmetry, and Other Parameters in the Neutral Kaon System

    Full text link
    We present precise tests of CP and CPT symmetry based on the full dataset of K to pipi decays collected by the KTeV experiment at Fermi National Accelerator Laboratory during 1996, 1997, and 1999. This dataset contains 16 million K to 2pi0 and 69 million K to pi+pi- decays. We measure the direct CP violation parameter Re(epsilon'/epsilon) = (19.2 pm 2.1)x10-4. We find the KL-KS mass difference Deltam = (5270 pm 12)x10^6 hbar/s and the KS lifetime tauS = (89.62 pm 0.05)x10-12 s. We also measure several parameters that test CPT invariance. We find the difference between the phase of the indirect CP violation parameter, epsilon, and the superweak phase, phi_epsilon - phi_SW = (0.40 pm 0.56) degrees. We measure the difference of the relative phases between the CP violating and CP conserving decay amplitudes for K to pi+pi- (phi+-) and for K to 2pi0 (phi00), Delta phi = (0.30 pm 0.35) degrees. From these phase measurements, we place a limit on the mass difference between K0 and K0bar, DeltaM < 4.8 x 10-19 GeV/c^2 at 95% C.L. These results are consistent with those of other experiments, our own earlier measurements, and CPT symmetry.Comment: 28 pages, 30 figures; removed extra figur

    Search for the Rare Decay KL --> pi0 ee

    Full text link
    The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay KL--> pi0ee. This mode is expected to have a significant CP violating component. The measurement of its branching ratio could support the Standard Model or could indicate the existence of new physics. This letter reports new results from the 1999-2000 data set. One event is observed with an expected background at 0.99 +/- 0.35 events. We set a limit on the branching ratio of 3.5 x 10^(-10) at the 90% confidence level. Combining the results with the dataset taken in 1997 yields the final KTeV result: BR(KL --> pi0 ee) < 2.8 x 10^(-10) at 90% CL.Comment: 4 pages, three figure

    Search for Light Gluinos via the Spontaneous Appearance of pi+pi- Pairs with an 800 GeV/c Proton Beam at Fermilab

    Get PDF
    We searched for the appearance of pi+pi- pairs with invariant mass greater than 648 MeV in a neutral beam. Such an observation could signify the decay of a long-lived light neutral particle. We find no evidence for this decay. Our null result severely constrains the existence of an R0 hadron, which is the lightest bound state of a gluon and a light gluino, and thereby also the possibility of a light gluino. Depending on the photino mass, we exclude the R0 in the mass and lifetime ranges of 1.2 -- 4.6 GeV and 2E-10 -- 7E-4 seconds, respectively. (To Appear in Phys. Rev. Lett.)Comment: Documentstyle aps,epsfig,prl (revtex), 6 pages, 7 figure

    Measurements of KL Branching Fractions and the CP Violation Parameter |eta+-|

    Full text link
    We present new measurements of the six largest branching fractions of the KL using data collected in 1997 by the KTeV experiment (E832) at Fermilab. The results are B(KL -> pi e nu) = 0.4067 +- 0.0011 B(KL -> pi mu nu) = 0.2701 +- 0.0009 B(KL -> pi+ pi- pi0) = 0.1252 +- 0.0007 B(KL -> pi0 pi0 pi0) = 0.1945 +- 0.0018 B(KL -> pi+ pi-) = (1.975 +- 0.012)E-3, and B(KL -> pi0 pi0) = (0.865 +- 0.010)E-3, where statistical and systematic errors have been summed in quadrature. We also determine the CP violation parameter |eta+-| to be (2.228 +- 0.010)E-3. Several of these results are not in good agreement with averages of previous measurements.Comment: Submitted to Phys. Rev. D; 20 pages, 22 figure

    First Observation of the decay KL -> pi0 e e gamma

    Full text link
    We report on the first observation of the decay KL -> pi0 ee gamma by the KTeV E799 experiment at Fermilab. Based upon a sample of 48 events with an estimated background of 3.6 +/- 1.1 events, we measure the KL -> pi0 ee gamma branching ratio to be (2.34 +/- 0.35 +/- 0.13)x10^{-8}. Our data agree with recent O(p^6) calculations in chiral perturbation theory that include contributions from vector meson exchange through the parameter a_V. A fit was made to the KL -> pi0 ee gamma data for a_V with the result -0.67 +/- 0.21 +/- 0.12, which is consistent with previous results from KTeV.Comment: Submitted to Physical Review Letters, 5 pages, 5 figure

    Observation of CP Violation in K(L)->pi+pi-e+e- Decays

    Full text link
    We report the first observation of a manifestly CP violating effect in the K(L)->pi+pi-e+e- decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle phi between the decay planes of the e+e- and pi+pi- pairs in the K(L) center of mass system. After acceptance corrections, the overall asymmetry is found to be 13.6+-2.5 (stat) +-1.2 (syst)%. This is the largest CP-violating effect yet observed integrating over the entire phase space of a mode and the first such effect observed in an angular variable.Comment: 4 pages 4 figures submitted to pr
    corecore