184 research outputs found

    Risk factors for nosocomial pneumonia comparing adult critical-care populations

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    The purpose of the study was to examine risk factors for nosocomial pneumonia in the surgical and medical/respiratory intensive care unit (ICU) populations. In a public teaching hospital, all cases of nosocomial pneumonia in the surgical and medical/respiratory ICUs (n = 20, respectively) were identified by prospective surveillance during a 5-yr period from 1987-1991. Each group of ICU cases was compared with 40 ICU control patients who did not acquire pneumonia, and analyzed for 25 potential risk factors. Surgical ICU patients were found to have consistently higher rates of nosocomial pneumonia than medical ICU patients (RR = 2.2). The strongest predictor for nosocomial pneumonia in both the surgical and medical/respiratory ICU groups was found to be prolonged mechanical ventilation (> 1 d) resulting in a 12-fold increase in risk over nonventilated patients. APACHE III score was found to be predictive of nosocomial pneumonia in the surgical ICU population, but not in the medical/respiratory ICU population. We conclude that certain groups deserve special attention for infection control intervention. Surgical ICU patients with high APACHE scores and receiving prolonged mechanical ventilation may be at the greatest risk of acquiring nosocomial pneumonia of all hospitalized patients

    Relativistic Calculation of the Meson Spectrum: a Fully Covariant Treatment Versus Standard Treatments

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    A large number of treatments of the meson spectrum have been tried that consider mesons as quark - anti quark bound states. Recently, we used relativistic quantum "constraint" mechanics to introduce a fully covariant treatment defined by two coupled Dirac equations. For field-theoretic interactions, this procedure functions as a "quantum mechanical transform of Bethe-Salpeter equation". Here, we test its spectral fits against those provided by an assortment of models: Wisconsin model, Iowa State model, Brayshaw model, and the popular semi-relativistic treatment of Godfrey and Isgur. We find that the fit provided by the two-body Dirac model for the entire meson spectrum competes with the best fits to partial spectra provided by the others and does so with the smallest number of interaction functions without additional cutoff parameters necessary to make other approaches numerically tractable. We discuss the distinguishing features of our model that may account for the relative overall success of its fits. Note especially that in our approach for QCD, the resulting pion mass and associated Goldstone behavior depend sensitively on the preservation of relativistic couplings that are crucial for its success when solved nonperturbatively for the analogous two-body bound-states of QED.Comment: 75 pages, 6 figures, revised content

    Đ˜ŃŃ‚ĐŸŃ€ĐžŃ разĐČотоя фОзОчДсĐșĐŸĐč ĐșŃƒĐ»ŃŒŃ‚ŃƒŃ€Ń‹ Đž ŃĐżĐŸŃ€Ń‚Đ° ĐœĐ° УралД ĐČ ĐŽĐŸŃ€Đ”ĐČĐŸĐ»ŃŽŃ†ĐžĐŸĐœĐœŃ‹Đč ĐżĐ”Ń€ĐžĐŸĐŽ

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    На ŃĐ”ĐłĐŸĐŽĐœŃŃˆĐœĐžĐč ĐŽĐ”ĐœŃŒ ŃŃ‚Đ°ĐœĐŸĐČотся чрДзĐČычаĐčĐœĐŸ Đ°ĐșŃ‚ŃƒĐ°Đ»ŃŒĐœŃ‹ĐŒ Ń€Đ°ŃŃĐŒĐŸŃ‚Ń€Đ”ĐœĐžĐ” Ń„Đ”ĐœĐŸĐŒĐ”ĐœĐ° фОзОчДсĐșĐŸĐč ĐșŃƒĐ»ŃŒŃ‚ŃƒŃ€Ń‹ Đž ŃĐżĐŸŃ€Ń‚Đ° сĐșĐČĐŸĐ·ŃŒ ĐżŃ€ĐžĐ·ĐŒŃƒ ĐżŃ€ĐžĐœŃ†ĐžĐżĐ° ĐžŃŃ‚ĐŸŃ€ĐžĐ·ĐŒĐ°. ĐĄŃƒŃ‰Đ”ŃŃ‚ĐČŃƒĐ”Ń‚ ДщД ĐŒĐœĐŸĐłĐŸ ĐœĐ”ĐžĐ·ĐČĐ”ŃŃ‚ĐœĐŸĐłĐŸ ĐČ ĐžŃŃ‚ĐŸŃ€ĐžĐž фОзОчДсĐșĐŸĐč ĐșŃƒĐ»ŃŒŃ‚ŃƒŃ€Ń‹, Ń‡Ń‚ĐŸ Ń‚Ń€Đ”Đ±ŃƒĐ”Ń‚ ĐżĐ”Ń€Đ”ĐŸŃ†Đ”ĐœĐșĐž ŃĐŸĐ±Ń‹Ń‚ĐžĐč, фаĐșŃ‚ĐŸĐČ Ń ĐżĐŸĐ·ĐžŃ†ĐžĐž ŃĐŸĐČŃ€Đ”ĐŒĐ”ĐœĐœĐŸŃŃ‚

    Detector Description and Performance for the First Coincidence Observations between LIGO and GEO

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    For 17 days in August and September 2002, the LIGO and GEO interferometer gravitational wave detectors were operated in coincidence to produce their first data for scientific analysis. Although the detectors were still far from their design sensitivity levels, the data can be used to place better upper limits on the flux of gravitational waves incident on the earth than previous direct measurements. This paper describes the instruments and the data in some detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial change

    Test beam performance measurements for the Phase I upgrade of the CMS pixel detector

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    A new pixel detector for the CMS experiment was built in order to cope with the instantaneous luminosities anticipated for the Phase I Upgrade of the LHC. The new CMS pixel detector provides four-hit tracking with a reduced material budget as well as new cooling and powering schemes. A new front-end readout chip mitigates buffering and bandwidth limitations, and allows operation at low comparator thresholds. In this paper, comprehensive test beam studies are presented, which have been conducted to verify the design and to quantify the performance of the new detector assemblies in terms of tracking efficiency and spatial resolution. Under optimal conditions, the tracking efficiency is (99.95 ± 0.05) %, while the intrinsic spatial resolutions are (4.80 ± 0.25) Όm and (7.99 ± 0.21) Όm along the 100 Όm and 150 Όm pixel pitch, respectively. The findings are compared to a detailed Monte Carlo simulation of the pixel detector and good agreement is found.Peer reviewe

    Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

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    Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale
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