391 research outputs found

    Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

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    Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

    Outcomes of Early Versus Late Tracheostomy in Patients With COVID-19: A Multinational Cohort Study

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    Objectives:. Timing of tracheostomy in patients with COVID-19 has attracted substantial attention. Initial guidelines recommended delaying or avoiding tracheostomy due to the potential for particle aerosolization and theoretical risk to providers. However, early tracheostomy could improve patient outcomes and alleviate resource shortages. This study compares outcomes in a diverse population of hospitalized COVID-19 patients who underwent tracheostomy either “early” (within 14 d of intubation) or “late” (more than 14 d after intubation). Design:. International multi-institute retrospective cohort study. Setting:. Thirteen hospitals in Bolivia, Brazil, Spain, and the United States. Patients:. Hospitalized patients with COVID-19 undergoing early or late tracheostomy between March 1, 2020, and March 31, 2021. Interventions:. Not applicable. Measurements and Main Results:. A total of 549 patients from 13 hospitals in four countries were included in the final analysis. Multivariable regression analysis showed that early tracheostomy was associated with a 12-day decrease in time on mechanical ventilation (95% CI, −16 to −8; p < 0.001). Further, ICU and hospital lengths of stay in patients undergoing early tracheostomy were 15 days (95% CI, −23 to −9 d; p < 0.001) and 22 days (95% CI, −31 to −12 d) shorter, respectively. In contrast, early tracheostomy patients experienced lower risk-adjusted survival at 30-day post-admission (hazard ratio, 3.0; 95% CI, 1.8−5.2). Differences in 90-day post-admission survival were not identified. Conclusions:. COVID-19 patients undergoing tracheostomy within 14 days of intubation have reduced ventilator dependence as well as reduced lengths of stay. However, early tracheostomy patients experienced lower 30-day survival. Future efforts should identify patients most likely to benefit from early tracheostomy while accounting for location-specific capacity

    Outcomes of Early Versus Late Tracheostomy in Patients With COVID-19: A Multinational Cohort Study.

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    UNLABELLED: Timing of tracheostomy in patients with COVID-19 has attracted substantial attention. Initial guidelines recommended delaying or avoiding tracheostomy due to the potential for particle aerosolization and theoretical risk to providers. However, early tracheostomy could improve patient outcomes and alleviate resource shortages. This study compares outcomes in a diverse population of hospitalized COVID-19 patients who underwent tracheostomy either early (within 14 d of intubation) or late (more than 14 d after intubation). DESIGN: International multi-institute retrospective cohort study. SETTING: Thirteen hospitals in Bolivia, Brazil, Spain, and the United States. PATIENTS: Hospitalized patients with COVID-19 undergoing early or late tracheostomy between March 1, 2020, and March 31, 2021. INTERVENTIONS: Not applicable. MEASUREMENTS AND MAIN RESULTS: A total of 549 patients from 13 hospitals in four countries were included in the final analysis. Multivariable regression analysis showed that early tracheostomy was associated with a 12-day decrease in time on mechanical ventilation (95% CI, -16 to -8; p \u3c 0.001). Further, ICU and hospital lengths of stay in patients undergoing early tracheostomy were 15 days (95% CI, -23 to -9 d; p \u3c 0.001) and 22 days (95% CI, -31 to -12 d) shorter, respectively. In contrast, early tracheostomy patients experienced lower risk-adjusted survival at 30-day post-admission (hazard ratio, 3.0; 95% CI, 1.8-5.2). Differences in 90-day post-admission survival were not identified. CONCLUSIONS: COVID-19 patients undergoing tracheostomy within 14 days of intubation have reduced ventilator dependence as well as reduced lengths of stay. However, early tracheostomy patients experienced lower 30-day survival. Future efforts should identify patients most likely to benefit from early tracheostomy while accounting for location-specific capacity

    Multiplicity dependence of light (anti-)nuclei production in p–Pb collisions at sNN=5.02 TeV

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    The measurement of the deuteron and anti-deuteron production in the rapidity range −1 < y < 0 as a function of transverse momentum and event multiplicity in p–Pb collisions at √sNN = 5.02 TeV is presented. (Anti-)deuterons are identified via their specific energy loss dE/dx and via their time-of- flight. Their production in p–Pb collisions is compared to pp and Pb–Pb collisions and is discussed within the context of thermal and coalescence models. The ratio of integrated yields of deuterons to protons (d/p) shows a significant increase as a function of the charged-particle multiplicity of the event starting from values similar to those observed in pp collisions at low multiplicities and approaching those observed in Pb–Pb collisions at high multiplicities. The mean transverse particle momenta are extracted from the deuteron spectra and the values are similar to those obtained for p and particles. Thus, deuteron spectra do not follow mass ordering. This behaviour is in contrast to the trend observed for non-composite particles in p–Pb collisions. In addition, the production of the rare 3He and 3He nuclei has been studied. The spectrum corresponding to all non-single diffractive p-Pb collisions is obtained in the rapidity window −1 < y < 0 and the pT-integrated yield dN/dy is extracted. It is found that the yields of protons, deuterons, and 3He, normalised by the spin degeneracy factor, follow an exponential decrease with mass number

    Abstracts of International Conference on Innovations in Business Management

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    This book contains abstracts of the various research ideas of the academic community and practitioners of management presented at the International Conference on Innovations in Business Management (ICIBM 2020). The researchers have contributed toward various themes of the conference such as sustainable economy, supply chain, women-empowerment, export-import, microfinance, government policies, etc. We strongly believe that it will open up further scope for in-depth research in various disciplines of business management. Best wishes to the participants to have detailed discussions on the above-said wide range of areas. Conference Title: International Conference on Innovations in Business ManagementConference Acronym: ICIBM 2020Conference Date: 16-17 January 2020Conference Location: ICFAI University, Dehradun, IndiaConference Organizers: ICFAI Business School, ICFAI University, Dehradun, India &amp; University of Derby, United Kingdo

    Abstracts of National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020

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    This book presents the abstracts of the papers presented to the Online National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020 (RDMPMC-2020) held on 26th and 27th August 2020 organized by the Department of Metallurgical and Materials Science in Association with the Department of Production and Industrial Engineering, National Institute of Technology Jamshedpur, Jharkhand, India. Conference Title: National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020Conference Acronym: RDMPMC-2020Conference Date: 26–27 August 2020Conference Location: Online (Virtual Mode)Conference Organizer: Department of Metallurgical and Materials Engineering, National Institute of Technology JamshedpurCo-organizer: Department of Production and Industrial Engineering, National Institute of Technology Jamshedpur, Jharkhand, IndiaConference Sponsor: TEQIP-

    Analysis of the apparent nuclear modification in peripheral Pb–Pb collisions at 5.02 TeV

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    International audienceCharged-particle spectra at midrapidity are measured in Pb–Pb collisions at the centre-of-mass energy per nucleon–nucleon pair sNN=5.02 TeV and presented in centrality classes ranging from most central (0–5%) to most peripheral (95–100%) collisions. Possible medium effects are quantified using the nuclear modification factor ( RAA ) by comparing the measured spectra with those from proton–proton collisions, scaled by the number of independent nucleon–nucleon collisions obtained from a Glauber model. At large transverse momenta ( 8<pT<20GeV/c ), the average RAA is found to increase from about 0.15 in 0–5% central to a maximum value of about 0.8 in 75–85% peripheral collisions, beyond which it falls off strongly to below 0.2 for the most peripheral collisions. Furthermore, RAA initially exhibits a positive slope as a function of pT in the 8–20 GeV/c interval, while for collisions beyond the 80% class the slope is negative. To reduce uncertainties related to event selection and normalization, we also provide the ratio of RAA in adjacent centrality intervals. Our results in peripheral collisions are consistent with a PYTHIA-based model without nuclear modification, demonstrating that biases caused by the event selection and collision geometry can lead to the apparent suppression in peripheral collisions. This explains the unintuitive observation that RAA is below unity in peripheral Pb–Pb, but equal to unity in minimum-bias p–Pb collisions despite similar charged-particle multiplicities

    Anisotropic flow of identified particles in Pb-Pb collisions at sNN=5.02 {\sqrt{s}}_{\mathrm{NN}}=5.02 TeV

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    The elliptic (v2_{2}), triangular (v3_{3}), and quadrangular (v4_{4}) flow coefficients of π±^{±}, K±^{±}, p+p,Λ+Λ,KS0 \mathrm{p}+\overline{\mathrm{p}},\kern0.5em \Lambda +\overline{\Lambda},\kern0.5em {\mathrm{K}}_{\mathrm{S}}^0 , and the ϕ-meson are measured in Pb-Pb collisions at sNN=5.02 {\sqrt{s}}_{\mathrm{NN}}=5.02 TeV. Results obtained with the scalar product method are reported for the rapidity range |y| < 0.5 as a function of transverse momentum, pT_{T}, at different collision centrality intervals between 0–70%, including ultra-central (0–1%) collisions for π±^{±}, K±^{±}, and p+p \mathrm{p}+\overline{\mathrm{p}} . For pT_{T} < 3 GeV/c, the flow coefficients exhibit a particle mass dependence. At intermediate transverse momenta (3 < pT_{T} < 8–10 GeV/c), particles show an approximate grouping according to their type (i.e., mesons and baryons). The ϕ-meson v2_{2}, which tests both particle mass dependence and type scaling, follows p+p \mathrm{p}+\overline{\mathrm{p}} v2_{2} at low pT_{T} and π±^{±} v2_{2} at intermediate pT_{T}. The evolution of the shape of vn_{n}(pT_{T}) as a function of centrality and harmonic number n is studied for the various particle species. Flow coefficients of π±^{±}, K±^{±}, and p+p \mathrm{p}+\overline{\mathrm{p}} for pT_{T} < 3 GeV/c are compared to iEBE-VISHNU and MUSIC hydrodynamical calculations coupled to a hadronic cascade model (UrQMD). The iEBE-VISHNU calculations describe the results fairly well for pT_{T} < 2.5 GeV/c, while MUSIC calculations reproduce the measurements for pT_{T} < 1 GeV/c. A comparison to vn_{n} coefficients measured in Pb-Pb collisions at sNN=2.76 \sqrt{s_{\mathrm{NN}}}=2.76 TeV is also provided

    Jet fragmentation transverse momentum distributions in pp and p-Pb collisions at s \sqrt{s} , sNN \sqrt{s_{\mathrm{NN}}} = 5.02 TeV

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    Jet fragmentation transverse momentum (jT_{T}) distributions are measured in proton-proton (pp) and proton-lead (p-Pb) collisions at sNN \sqrt{s_{\mathrm{NN}}} = 5.02 TeV with the ALICE experiment at the LHC. Jets are reconstructed with the ALICE tracking detectors and electromagnetic calorimeter using the anti-kT_{T} algorithm with resolution parameter R = 0.4 in the pseudorapidity range |η| < 0.25. The jT_{T} values are calculated for charged particles inside a fixed cone with a radius R = 0.4 around the reconstructed jet axis. The measured jT_{T} distributions are compared with a variety of parton-shower models. Herwig and Pythia 8 based models describe the data well for the higher jT_{T} region, while they underestimate the lower jT_{T} region. The jT_{T} distributions are further characterised by fitting them with a function composed of an inverse gamma function for higher jT_{T} values (called the “wide component”), related to the perturbative component of the fragmentation process, and with a Gaussian for lower jT_{T} values (called the “narrow component”), predominantly connected to the hadronisation process. The width of the Gaussian has only a weak dependence on jet transverse momentum, while that of the inverse gamma function increases with increasing jet transverse momentum. For the narrow component, the measured trends are successfully described by all models except for Herwig. For the wide component, Herwig and PYTHIA 8 based models slightly underestimate the data for the higher jet transverse momentum region. These measurements set constraints on models of jet fragmentation and hadronisation

    Production of charged pions, kaons, and (anti-)protons in Pb-Pb and inelastic pppp collisions at sNN\sqrt {s_{NN}} = 5.02 TeV

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    International audienceMid-rapidity production of π±\pi^{\pm}, K±\rm{K}^{\pm} and (pˉ\bar{\rm{p}})p measured by the ALICE experiment at the LHC, in Pb-Pb and inelastic pp collisions at sNN\sqrt{s_{\rm{NN}}} = 5.02 TeV, is presented. The invariant yields are measured over a wide transverse momentum (pTp_{\rm{T}}) range from hundreds of MeV/cc up to 20 GeV/cc. The results in Pb-Pb collisions are presented as a function of the collision centrality, in the range 0-90%. The comparison of the pTp_{\rm{T}}-integrated particle ratios, i.e. proton-to-pion (p/π\pi) and kaon-to-pion (K/π\pi) ratios, with similar measurements in Pb-Pb collisions at sNN\sqrt{s_{\rm{NN}}} = 2.76 TeV show no significant energy dependence. Blast-wave fits of the pTp_{\rm{T}} spectra indicate that in the most central collisions radial flow is slightly larger at 5.02 TeV with respect to 2.76 TeV. Particle ratios (p/π\pi, K/π\pi) as a function of pTp_{\rm{T}} show pronounced maxima at pTp_{\rm{T}} \approx 3 GeV/cc in central Pb-Pb collisions. At high pTp_{\rm{T}}, particle ratios at 5.02 TeV are similar to those measured in pp collisions at the same energy and in Pb-Pb collisions at sNN\sqrt{s_{\rm{NN}}} = 2.76 TeV. Using the pp reference spectra measured at the same collision energy of 5.02 TeV, the nuclear modification factors for the different particle species are derived. Within uncertainties, the nuclear modification factor is particle species independent for high pTp_{\rm{T}} and compatible with measurements at sNN\sqrt{s_{\rm{NN}}} = 2.76 TeV. The results are compared to state-of-the-art model calculations, which are found to describe the observed trends satisfactorily
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