15 research outputs found

    Validation of an Asian cerebrovascular risk prediction model in multiethnic country population

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    Objective: The importance of using risk prediction instruments to control cerebrovascular risk factors has been emphasized in most of the latest evidenced-based stroke prevention guidelines. The value of inclusion of stroke in cardiovascular risk prediction instruments are increasingly recognized as part of the outcome cluster. However, the lacking of validation of these cerebrovascular risk models in a multiethnic population limits its use in primary stroke prevention, particular in a multiethnic country. This study aimed to evaluate the validity of the Chinese Adults 10-Year Risk of Fatal and Non-fatal Ischemic Cardiovascular Diseases Risk Score. Design and method: Patients aged 35–59 were randomly selected and included in this 10-year retrospective cohort study. Patient medical records such as baseline demographic characteristics, comorbidities and cerebrovascular risk parameters were documented. The 10-Year risk scores according to Chinese Adults 10-Year Risk of Fatal and Non-fatal Ischemic Cardiovascular Diseases Risk Score were computed. Results: A total of 622 patients were studied. The actual number of stroke that occurred in the 10 years was 20 (20/662 = 3.0%) whereas the predicted was 21 (3.2%). The actual event in the low-risk group (20%); the actual event and the predicted event were 0 (0%) and 2 (29.7%) respectively. The Chinese 10-Year risk score has a poor discrimination index in this studied population as the area under the curve (AUC) is 0.43, with p value of 0.310. There was good calibration with Hosmer-Lemeshow test X2 = 4.48, P = 0.48. Conclusions: The risk score appears to underestimate stroke risk in low-risk group whereas it appears overestimate in the intermediate and high risk group. The results suggest that this risk model is unlikely to provide an appropriate stroke risk estimation. Future validation study with a larger population sample size is therefore advised

    Basis for a wireless network for eMC measurements in electric substations

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    Switching operations of power equipment such as disconnect switch and circuit breakers in high voltage substations produce high frequency transient currents, which propagate along the busbars. The busbars then act as antennae, producing transient electromagnetic fields in the switchyards. In electromagnetic compatibility (EMC) considerations, the resulting fields are important sources of electromagnetic interference (EMI); moreover, highly sophisticated,. new technology equipment are being introduced into substation environment for measurement, control, protection and communication purposes. These equipment are located close to other switching equipment in switchyards. Hence, to establish the electromagnetic compatibility of the electronic equipment, it is desirable to quantify the high voltage environment. This paper describes a new digital wireless measurement system that is based on Bluetooth technology and which could be used in power stations or other similar harsh environment. It comprises a Remote Acquisition Unit (RAU), a Wireless Data Communication Network (WDCN) and a PC-based Control Platform. The performance and capability of the system was assessed against another measurement system based on fiber optics technology and was found to be more portable, easier to install and cheaper. The limitations of the wireless system are considered and ways of addressing them in the future are discussed

    Precision luminosity measurement in proton-proton collisions at root S=13 TeV in 2015 and 2016 at CMS

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    The measurement of the luminosity recorded by the CMS detector installed at LHC interaction point 5, using proton-proton collisions at root S = 13 TeV in 2015 and 2016, is reported. The absolute luminosity scale is measured for individual bunch crossings using beam-separation scans (the van der Meer method), with a relative precision of 1.3 and 1.0% in 2015 and 2016, respectively. The dominant sources of uncertainty are related to residual differences between the measured beam positions and the ones provided by the operational settings of the LHC magnets, the factorizability of the proton bunch spatial density functions in the coordinates transverse to the beam direction, and the modeling of the effect of electromagnetic interactions among protons in the colliding bunches. When applying the van der Meer calibration to the entire run periods, the integrated luminosities when CMS was fully operational are 2.27 and 36.3 fb(-1) in 2015 and 2016, with a relative precision of 1.6 and 1.2%, respectively. These are among the most precise luminosity measurements at bunched-beam hadron colliders.Peer reviewe

    Summer Diapause as a Special Seasonal Adaptation in Insects: Diversity of Forms, Control Mechanisms, and Ecological Importance

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    Measurement of inclusive and differential cross sections for single top quark production in association with a W boson in proton-proton collisions at s \sqrt{s} = 13 TeV

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    International audienceMeasurements of the inclusive and normalised differential cross sections are presented for the production of single top quarks in association with a W boson in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data used were recorded with the CMS detector at the LHC during 2016–2018, and correspond to an integrated luminosity of 138 fb1^{−1}. Events containing one electron and one muon in the final state are analysed. For the inclusive measurement, a multivariate discriminant, exploiting the kinematic properties of the events is used to separate the signal from the dominant tt \textrm{t}\overline{\textrm{t}} background. A cross section of 79.2±0.9(stat)8.0+7.7(syst)±1.2(lumi) 79.2\pm 0.9{\left(\textrm{stat}\right)}_{-8.0}^{+7.7}\left(\textrm{syst}\right)\pm 1.2\left(\textrm{lumi}\right) pb is obtained, consistent with the predictions of the standard model. For the differential measurements, a fiducial region is defined according to the detector acceptance, and the requirement of exactly one jet coming from the fragmentation of a bottom quark. The resulting distributions are unfolded to particle level and agree with the predictions at next-to-leading order in perturbative quantum chromodynamics.[graphic not available: see fulltext

    Search for pair production of vector-like quarks in leptonic final states in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A search is presented for vector-like T \mathrm{T} and B \mathrm{B} quark-antiquark pairs produced in proton-proton collisions at a center-of-mass energy of 13 TeV. Data were collected by the CMS experiment at the CERN LHC in 2016-2018, with an integrated luminosity of 138 fb1 ^{-1} . Events are separated into single-lepton, same-sign charge dilepton, and multilepton channels. In the analysis of the single-lepton channel a multilayer neural network and jet identification techniques are employed to select signal events, while the same-sign dilepton and multilepton channels rely on the high-energy signature of the signal to distinguish it from standard model backgrounds. The data are consistent with standard model background predictions, and the production of vector-like quark pairs is excluded at 95% confidence level for T \mathrm{T} quark masses up to 1.54 TeV and B \mathrm{B} quark masses up to 1.56 TeV, depending on the branching fractions assumed, with maximal sensitivity to decay modes that include multiple top quarks. The limits obtained in this search are the strongest limits to date for TT \mathrm{T} \overline{\mathrm{T}} production, excluding masses below 1.48 TeV for all decays to third generation quarks, and are the strongest limits to date for BB \mathrm{B} \overline{\mathrm{B}} production with B \mathrm{B} quark decays to tW.A search is presented for vector-like T and B quark-antiquark pairs produced in proton-proton collisions at a center-of-mass energy of 13 TeV. Data were collected by the CMS experiment at the CERN LHC in 2016–2018, with an integrated luminosity of 138 fb1^{−1}. Events are separated into single-lepton, same-sign charge dilepton, and multi-lepton channels. In the analysis of the single-lepton channel a multilayer neural network and jet identification techniques are employed to select signal events, while the same-sign dilepton and multilepton channels rely on the high-energy signature of the signal to distinguish it from standard model backgrounds. The data are consistent with standard model background predictions, and the production of vector-like quark pairs is excluded at 95% confidence level for T quark masses up to 1.54 TeV and B quark masses up to 1.56 TeV, depending on the branching fractions assumed, with maximal sensitivity to decay modes that include multiple top quarks. The limits obtained in this search are the strongest limits to date for TT \textrm{T}\overline{\textrm{T}} production, excluding masses below 1.48 TeV for all decays to third generation quarks, and are the strongest limits to date for BB \textrm{B}\overline{\textrm{B}} production with B quark decays to tW.[graphic not available: see fulltext]A search is presented for vector-like T and B quark-antiquark pairs produced in proton-proton collisions at a center-of-mass energy of 13 TeV. Data were collected by the CMS experiment at the CERN LHC in 2016-2018, with an integrated luminosity of 138 fb1^{-1}. Events are separated into single-lepton, same-sign charge dilepton, and multilepton channels. In the analysis of the single-lepton channel a multilayer neural network and jet identification techniques are employed to select signal events, while the same-sign dilepton and multilepton channels rely on the high-energy signature of the signal to distinguish it from standard model backgrounds. The data are consistent with standard model background predictions, and the production of vector-like quark pairs is excluded at 95% confidence level for T quark masses up to 1.54 TeV and B quark masses up to 1.56 TeV, depending on the branching fractions assumed, with maximal sensitivity to decay modes that include multiple top quarks. The limits obtained in this search are the strongest limits to date for TT\mathrm{T\overline{T}} production, excluding masses below 1.48 TeV for all decays to third generation quarks, and are the strongest limits to date for BB\mathrm{B\overline{B}} production with B quark decays to tW

    Measurement of the Higgs boson inclusive and differential fiducial production cross sections in the diphoton decay channel with pp collisions at s \sqrt{s} = 13 TeV

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    International audienceThe measurements of the inclusive and differential fiducial cross sections of the Higgs boson decaying to a pair of photons are presented. The analysis is performed using proton-proton collisions data recorded with the CMS detector at the LHC at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 137 fb1^{−1}. The inclusive fiducial cross section is measured to be σfid=73.45.3+5.4(stat)2.2+2.4(syst) {\sigma}_{\textrm{fid}}={73.4}_{-5.3}^{+5.4}{\left(\textrm{stat}\right)}_{-2.2}^{+2.4}\left(\textrm{syst}\right) fb, in agreement with the standard model expectation of 75.4 ± 4.1 fb. The measurements are also performed in fiducial regions targeting different production modes and as function of several observables describing the diphoton system, the number of additional jets present in the event, and other kinematic observables. Two double differential measurements are performed. No significant deviations from the standard model expectations are observed.[graphic not available: see fulltext
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