978 research outputs found

    Managing emerging challenges of Coronavirus disease 2019 (COVID-19) in dentistry

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    Dental centers have been referred to as a hub or reservoir for infection, where healthcare professionals and other staff, patients and the public together may potentially spread pathogenic microorganisms. This may occur via saliva, skin or indirectly through air, water, and contaminated surfaces or instruments. Everyone should therefore be considered as potential sources of infection. During a pandemic, limiting unnecessary care has been adopted as a clinical measure for some patient’s, to reduce the risk of cross-infection in the short term. However, in order to enable continuation of necessary and qualified care, dental processes need to follow specific infection control strategies in order to prevent transmission of emerging pandemic risks following COVID19. In this article, we develop a tool with practical recommendations to mitigate infection risks before, during and following pandemics to enable ongoing dental care provision in primary and secondary care based on national and global recommendations

    Video fire detection - Review

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    Cataloged from PDF version of article.This is a review article describing the recent developments in Video based Fire Detection (VFD). Video surveillance cameras and computer vision methods are widely used in many security applications. It is also possible to use security cameras and special purpose infrared surveillance cameras for fire detection. This requires intelligent video processing techniques for detection and analysis of uncontrolled fire behavior. VFD may help reduce the detection time compared to the currently available sensors in both indoors and outdoors because cameras can monitor “volumes” and do not have transport delay that the traditional “point” sensors suffer from. It is possible to cover an area of 100 km2 using a single pan-tiltzoom camera placed on a hilltop for wildfire detection. Another benefit of the VFD systems is that they can provide crucial information about the size and growth of the fire, direction of smoke propagation. © 2013 Elsevier Inc. All rights reserve

    Beautiful Mirrors at the LHC

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    We explore the "Beautiful Mirrors" model, which aims to explain the measured value of AFBbA^b_{FB}, discrepant at the 2.9σ2.9\sigma level. This scenario introduces vector-like quarks which mix with the bottom, subtly affecting its coupling to the ZZ. The spectrum of the new particles consists of two bottom-like quarks and a charge -4/3 quark, all of which have electroweak interactions with the third generation. We explore the phenomenology and discovery reach for these new particles at the LHC, exploring single mirror quark production modes whose rates are proportional to the same mixing parameters which resolve the AFBbA_{FB}^b anomaly. We find that for mirror quark masses 500GeV,a14TeVLHCwith300fb1\lesssim 500 GeV, a 14 TeV LHC with 300 {\rm fb}^{-1} is required to reasonably establish the scenario and extract the relevant mixing parameters.Comment: version to be published in JHE

    A search for resonant production of ttˉt\bar{t} pairs in $4.8\ \rm{fb}^{-1}ofintegratedluminosityof of integrated luminosity of p\bar{p}collisionsat collisions at \sqrt{s}=1.96\ \rm{TeV}$

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    We search for resonant production of tt pairs in 4.8 fb^{-1} integrated luminosity of ppbar collision data at sqrt{s}=1.96 TeV in the lepton+jets decay channel, where one top quark decays leptonically and the other hadronically. A matrix element reconstruction technique is used; for each event a probability density function (pdf) of the ttbar candidate invariant mass is sampled. These pdfs are used to construct a likelihood function, whereby the cross section for resonant ttbar production is estimated, given a hypothetical resonance mass and width. The data indicate no evidence of resonant production of ttbar pairs. A benchmark model of leptophobic Z \rightarrow ttbar is excluded with m_{Z'} < 900 GeV at 95% confidence level.Comment: accepted for publication in Physical Review D Sep 21, 201

    Measurement of branching ratio and Bs0 lifetime in the decay Bs0 -> J/psi f0(980) at CDF

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    We present a study of Bs0 decays to the CP-odd final state J/psi f0(980) with J/psi -> mu+ mu- and f0(980) -> pi+ pi-. Using ppbar collision data with an integrated luminosity of 3.8/fb collected by the CDF II detector at the Tevatron we measure a Bs0 lifetime of tau(Bs0 -> J/psi f0(980)) = 1.70 -0.11+0.12(stat) +-0.03(syst) ps. This is the first measurement of the Bs0 lifetime in a decay to a CP eigenstate and corresponds in the standard model to the lifetime of the heavy Bs0 eigenstate. We also measure the product of branching fractions of Bs0 -> J/psi f0(980) and f0(980) -> pi+ pi- relative to the product of branching fractions of Bs0 -> J/psi phi and phi -> K+ K- to be R_f0/phi = 0.257 +_0.020(stat) +-0.014(syst), which is the most precise determination of this quantity to date.Comment: accepted by Phys. Rev.

    Evidence for t\bar{t}\gamma Production and Measurement of \sigma_t\bar{t}\gamma / \sigma_t\bar{t}

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    Using data corresponding to 6.0/fb of ppbar collisions at sqrt(s) = 1.96 TeV collected by the CDF II detector, we present a cross section measurement of top-quark pair production with an additional radiated photon. The events are selected by looking for a lepton, a photon, significant transverse momentum imbalance, large total transverse energy, and three or more jets, with at least one identified as containing a b quark. The ttbar+photon sample requires the photon to have 10 GeV or more of transverse energy, and to be in the central region. Using an event selection optimized for the ttbar+photon candidate sample we measure the production cross section of, and the ratio of cross sections of the two samples. Control samples in the dilepton+photon and lepton+photon+\met, channels are constructed to aid in decay product identification and background measurements. We observe 30 ttbar+photon candidate events compared to the standard model expectation of 26.9 +/- 3.4 events. We measure the ttbar+photon cross section to be 0.18+0.08 pb, and the ratio of the cross section of ttbar+photon to ttbar to be 0.024 +/- 0.009. Assuming no ttbar+photon production, we observe a probability of 0.0015 of the background events alone producing 30 events or more, corresponding to 3.0 standard deviations.Comment: 9 pages, 3 figure

    Precision Top-Quark Mass Measurements at CDF

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    We present a precision measurement of the top-quark mass using the full sample of Tevatron s=1.96\sqrt{s}=1.96 TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb1fb^{-1}. Using a sample of ttˉt\bar{t} candidate events decaying into the lepton+jets channel, we obtain distributions of the top-quark masses and the invariant mass of two jets from the WW boson decays from data. We then compare these distributions to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with {\it in situ} calibration. The likelihood fit of the templates from signal and background events to the data yields the single most-precise measurement of the top-quark mass, \mtop = 172.85 \pm0.71(stat) 0.71 (stat) \pm0.85(syst)GeV/c2. 0.85 (syst) GeV/c^{2}.Comment: submitted to Phys. Rev. Let
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