1,750 research outputs found

    Wildlife collisions with aircraft: A missing component of land-use planning for airports

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    Projecting risks posed to aviation safety by wildlife populations is often overlooked in airport land-use planning. However, the growing dependency on civil aviation for global commerce can require increases in capacity at airports which affect land use, wildlife populations, and perspectives on aviation safety. Our objectives were to (1) review legislation that affects airports and surrounding communities relative to managing and reducing wildlife hazards to aviation; (2) identify information gaps and future research needs relative to regulated land uses on and near airports, and the effects on wildlife populations; and (3) demonstrate how information regarding wildlife responses to land-use practices can be incorporated into wildlife-strike risk assessments.We show that guidelines for land-use practices on and near airports with regard to wildlife hazards to aviation can be vague, conflicting, and scientifically ill-supported. We discuss research needs with regard to management of storm water runoff; wildlife use of agricultural crops and tillage regimens relative to revenue and safety; the role of an airport in the landscape matrix with regard to its effects on wildlife species richness and abundance; and spatial and temporal requirements of wildlife species that use airports, relative to implementing current and novel management techniques. We also encourage the development and maintenance of data sets that will allow realistic assessment of wildlife-strike risk relative to current airport conditions and anticipated changes to capacity. Land uses at airports influence wildlife populations, and understanding and incorporating these effects into planning will reduce risks posed to both aviation safety and wildlife species

    Genetic mechanisms of critical illness in COVID-19.

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    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

    Search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at s \sqrt{\mathrm{s}} = 13 TeV

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    Results are reported from a search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at s \sqrt{\mathrm{s}} = 13 TeV. The data sample corresponds to an integrated luminosity of 33.2 fb1^{-1} recorded by the CMS experiment at the LHC in 2016. The search exploits τ leptons produced in both W boson and heavy-flavor hadron decays. No significant excess above the expected background is observed. An upper limit on the branching fraction B(τ → 3μ) of 8.0 x 108^{-8} at 90% confidence level is obtained, with an expected upper limit of 6.9 x 108^{-8}

    Erratum to: Search for dark matter produced in association with a leptonically decaying Z{\mathrm{Z}} boson in proton–proton collisions at s=13TeV\sqrt{s}=13\,\text {Te}\text {V}

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    Search for invisible decays of the Higgs boson produced via vector boson fusion in proton-proton collisions at s\sqrt{s} = 13 TeV

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    A search for invisible decays of the Higgs boson produced via vector boson fusion (VBF) has been performed with 101  fb1^{-1} of proton-proton collisions delivered by the LHC at s\sqrt{s} =13  TeV and collected by the CMS detector in 2017 and 2018. The sensitivity to the VBF production mechanism is enhanced by constructing two analysis categories, one based on missing transverse momentum and a second based on the properties of jets. In addition to control regions with Z and W boson candidate events, a highly populated control region, based on the production of a photon in association with jets, is used to constrain the dominant irreducible background from the invisible decay of a Z boson produced in association with jets. The results of this search are combined with all previous measurements in the VBF topology, based on data collected in 2012 (at s\sqrt{s} =8  TeV), 2015, and 2016, corresponding to integrated luminosities of 19.7, 2.3, and 36.3  fb1^{-1}, respectively. The observed (expected) upper limit on the invisible branching fraction of the Higgs boson is found to be 0.18 (0.10) at the 95% confidence level, assuming the standard model production cross section. The results are also interpreted in the context of Higgs-portal models

    Observation of the Bc+_\mathrm{c}^+ Meson in Pb-Pb and pp Collisions at sNN\sqrt{s_{\mathrm{NN}}} = 5.02 TeV and Measurement of its Nuclear Modification Factor

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    The Bc+_\mathrm{c}^+ meson is observed for the first time in heavy ion collisions. Data from the CMS detector are used to study the production of the Bc+_\mathrm{c}^+ meson in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a center-of-mass energy per nucleon pair of sNN\sqrt{s_{\mathrm{NN}}} = 5.02 TeV , via the Bc+_\mathrm{c}^+ → (J/ψ → μ+^+μ^−+^+νμ decay. The Bc+_\mathrm{c}^+ nuclear modification factor, derived from the PbPb-to-pp ratio of production cross sections, is measured in two bins of the trimuon transverse momentum and of the PbPb collision centrality. The Bc+_\mathrm{c}^+meson is shown to be less suppressed than quarkonia and most of the open heavy-flavor mesons, suggesting that effects of the hot and dense nuclear matter created in heavy ion collisions contribute to its production. This measurement sets forth a promising new probe of the interplay of suppression and enhancement mechanisms in the production of heavy-flavor mesons in the quark-gluon plasma

    First Search for Exclusive Diphoton Production at High Mass with Tagged Protons in Proton-Proton Collisions at √s = 13 TeV

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    Measurement of the B0^{0}s_{s} → μ+^{+} μ^{-} decay properties and search for the B0^{0} → μ+^{+}μ^{-} decay in proton-proton collisions at √s = 13 TeV

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    Search for top squarks in the four-body decay mode with single lepton final states in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A search for the pair production of the lightest supersymmetric partner of the top quark, the top squark (t∼1), is presented. The search targets the four-body decay of the t∼1, which is preferred when the mass difference between the top squark and the lightest supersymmetric particle is smaller than the mass of the W boson. This decay mode consists of a bottom quark, two other fermions, and the lightest neutralino (χ∼01), which is assumed to be the lightest supersymmetric particle. The data correspond to an integrated luminosity of 138 fb−1 of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC. Events are selected using the presence of a high-momentum jet, an electron or muon with low transverse momentum, and a significant missing transverse momentum. The signal is selected based on a multivariate approach that is optimized for the difference between m(t∼1) and m(χ∼01). The contribution from leading background processes is estimated from data. No significant excess is observed above the expectation from standard model processes. The results of this search exclude top squarks at 95% confidence level for masses up to 480 and 700 GeV for m(t∼1) − m(χ∼01) = 10 and 80 GeV, respectively

    Search for a massive scalar resonance decaying to a light scalar and a Higgs boson in the four b quarks final state with boosted topology

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