2,814 research outputs found

    Decoupled Lithospheric Folding, Lower Crustal Flow Channels, and the Growth of Tibetan Plateau

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    The growth mechanism of the Tibetan Plateau, postulated by a number of hypotheses, remains under intense debate. Our analysis of recent satellite-based gravity model reveals that Tibetan lithosphere has been decoupled and folded. It is further evidenced by the existence of crustal melts and channel flow that have been observed by seismic and magnetotelluric explorations. Based on 3D geodynamic simulations, we elucidate the exact buckling structures in the upper crust and lithospheric mantle: at mixed wavelengths between āˆ¼240 and āˆ¼400 km, the lower crustal viscosity is smaller than āˆ¼10 19 PaĀ·s, implicating weak lower crustal flow beneath the Plateau. This mixed wavelength is consistent with the result of our inverse gravity modeling. Our results facilitate a new plausible hypothesis that the decoupled lithospheric folding mechanism can explain the growth mechanism of the anomalously thick and wide Tibetan Plateau by conflating our idea and contemporary hypothesized scientific findings

    Harnessing inter-disciplinary collaboration to improve emergency care in low- and middle-income countries (LMICs): results of research prioritisation setting exercise

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    Background More than half of deaths in low- and middle-income countries (LMICs) result from conditions that could be treated with emergency care - an integral component of universal health coverage (UHC) - through timely access to lifesaving interventions. Methods The World Health Organization (WHO) aims to extend UHC to a further 1 billion people by 2023, yet evidence supporting improved emergency care coverage is lacking. In this article, we explore four phases of a research prioritisation setting (RPS) exercise conducted by researchers and stakeholders from South Africa, Egypt, Nepal, Jamaica, Tanzania, Trinidad and Tobago, Tunisia, Colombia, Ethiopia, Iran, Jordan, Malaysia, South Korea and Phillipines, USA and UK as a key step in gathering evidence required by policy makers and practitioners for the strengthening of emergency care systems in limited-resource settings. Results The RPS proposed seven priority research questions addressing: identification of context-relevant emergency care indicators, barriers to effective emergency care; accuracy and impact of triage tools; potential quality improvement via registries; characteristics of people seeking emergency care; best practices for staff training and retention; and cost effectiveness of critical care ā€“ all within LMICs. Conclusions Convened by WHO and facilitated by the University of Sheffield, the Global Emergency Care Research Network project (GEM-CARN) brought together a coalition of 16 countries to identify research priorities for strengthening emergency care in LMICs. Our article further assesses the quality of the RPS exercise and reviews the current evidence supporting the identified priorities

    Systematic review and meta-analysis of intravascular temperature management vs. surface cooling in comatose patients resuscitated from cardiac arrest

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    Objective: To systematically review the effectiveness and safety of intravascular temperature management (IVTM) vs. surface cooling methods (SCM) for induced hypothermia (IH). Methods: Systematic review and meta-analysis. English-language PubMed, Embase and the Cochrane Database of Systematic Reviews were searched on May 27, 2019. The quality of included observational studies was graded using the Newcastle-Ottawa Quality Assessment tool. The quality of included randomized trials was evaluated using the Cochrane Collaboration's risk of bias tool. Random effects modeling was used to calculate risk differences for each outcome. Statistical heterogeneity and publication bias were assessed using standard methods. Eligibility: Observational or randomized studies comparing survival and/or neurologic outcomes in adults aged 18 years or greater resuscitated from out-of-hospital cardiac arrest receiving IH via IVTM vs. SCM were eligible for inclusion. Results: In total, 12 studies met inclusion criteria. These enrolled 1573 patients who received IVTM; and 4008 who received SCM. Survival was 55.0% in the IVTM group and 51.2% in the SCM group [pooled risk difference 2% (95% CI - 1%, 5%)] Good neurological outcome was achieved in 40.9% in the IVTM and 29.5% in the surface group [pooled risk difference 5% (95% CI 2%, 8%)]. There was a 6% (95% CI 11%, 2%) lower risk of arrhythmia with use of IVTM and 15% (95% CI 22%, 7%) decreased risk of overcooling with use of IVTM vs. SCM. There was no significant difference in other evaluated adverse events between groups. Conclusions: IVTM was associated with improved neurological outcomes vs. SCM among survivors resuscitated following cardiac arrest. These results may have implications for care of patients in the emergency department and intensive care settings after resuscitation from cardiac arrest.Peer reviewe

    Measurement of Ļ‡ c1 and Ļ‡ c2 production with sāˆš = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the Ļ‡ c1 and Ļ‡ c2 charmonium states are measured in pp collisions at sāˆš = 7 TeV with the ATLAS detector at the LHC using 4.5 fbāˆ’1 of integrated luminosity. The Ļ‡ c states are reconstructed through the radiative decay Ļ‡ c ā†’ J/ĻˆĪ³ (with J/Ļˆ ā†’ Ī¼ + Ī¼ āˆ’) where photons are reconstructed from Ī³ ā†’ e + e āˆ’ conversions. The production rate of the Ļ‡ c2 state relative to the Ļ‡ c1 state is measured for prompt and non-prompt Ļ‡ c as a function of J/Ļˆ transverse momentum. The prompt Ļ‡ c cross-sections are combined with existing measurements of prompt J/Ļˆ production to derive the fraction of prompt J/Ļˆ produced in feed-down from Ļ‡ c decays. The fractions of Ļ‡ c1 and Ļ‡ c2 produced in b-hadron decays are also measured

    Measurement of the production of a W boson in association with a charm quark in pp collisions at āˆšs = 7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fbāˆ’1 of pp collision data at sāˆš = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26āˆ’0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio Ļƒ(W + +cĀÆĀÆ)/Ļƒ(W āˆ’ + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the sāˆ’sĀÆĀÆĀÆ quark asymmetry

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

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    A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

    Standalone vertex ļ¬nding in the ATLAS muon spectrometer

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    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at āˆšs = 7 TeV collected with the ATLAS detector at the LHC during 2011

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

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    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H ā†’Ī³ Ī³, H ā†’ Z Zāˆ— ā†’4l and H ā†’W Wāˆ— ā†’lĪ½lĪ½. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of āˆšs = 7 TeV and āˆšs = 8 TeV, corresponding to an integrated luminosity of about 25 fbāˆ’1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined ļ¬ts probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson
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