84 research outputs found

    Spin pumping and magnetization dynamics in metallic multilayers

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    We study the magnetization dynamics in thin ferromagnetic films and small ferromagnetic particles in contact with paramagnetic conductors. A moving magnetization vector causes \textquotedblleft pumping\textquotedblright of spins into adjacent nonmagnetic layers. This spin transfer affects the magnetization dynamics similar to the Landau-Lifshitz-Gilbert phenomenology. The additional Gilbert damping is significant for small ferromagnets, when the nonmagnetic layers efficiently relax the injected spins, but the effect is reduced when a spin accumulation build-up in the normal metal opposes the spin pumping. The damping enhancement is governed by (and, in turn, can be used to measure) the mixing conductance or spin-torque parameter of the ferromagnet--normal-metal interface. Our theoretical findings are confirmed by agreement with recent experiments in a variety of multilayer systems.Comment: 10 pages, 6 figure

    Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study

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    A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4

    Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000–17 : analysis for the Global Burden of Disease Study 2017

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    Background Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea. Methods We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates. Findings The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage. Interpretation By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health

    Measurement of the tt¯ production cross-section in pp collisions at s√ = 5.02 TeV with the ATLAS detector

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    The inclusive top-quark pair (tt¯) production cross-section σtt¯ is measured in proton–proton collisions at a centre-of-mass energy s√ = 5.02 TeV, using 257 pb−1 of data collected in 2017 by the ATLAS experiment at the LHC. The tt¯ cross-section is measured in both the dilepton and single-lepton final states of the tt¯ system and then combined. The combination of the two measurements yields σtt¯=67.5±0.9(stat.)±2.3(syst.)±1.1(lumi.)±0.2(beam)pb, where the four uncertainties reflect the limited size of the data sample, experimental and theoretical systematic effects, and imperfect knowledge of both the integrated luminosity and the LHC beam energy, giving a total uncertainty of 3.9%. The result is in agreement with theoretical quantum chromodynamic calculations at next-to-next-to-leading order in the strong coupling constant, including the resummation of next-to-next-to-leading logarithmic soft-gluon terms, and constrains the parton distribution functions of the proton at large Bjorken-x

    Measurement of the Higgs boson mass in the H → ZZ⁎ → 4ℓ decay channel using 139 fb−1 of √s = 13 TeV pp collisions recorded by the ATLAS detector at the LHC

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    The mass of the Higgs boson is measured in the H → Z Z∗ → 4 decay channel. The analysis uses proton– proton collision data from the Large Hadron Collider at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector between 2015 and 2018, corresponding to an integrated luminosity of 139 fb−1. The measured value of the Higgs boson mass is 124.99 ± 0.18(stat.) ± 0.04(syst.) GeV. In final states with muons, this measurement benefits from an improved momentum-scale calibration relative to that adopted in previous publications. The measurement also employs an analytic model that takes into account the invariant-mass resolution of the four-lepton system on a per-event basis and the output of a deep neural network discriminating signal from background events. This measurement is combined with the corresponding measurement using 7 and 8 TeV pp collision data, resulting in a Higgs boson mass of 124.94 ± 0.17(stat.) ± 0.03(syst.) GeV

    Search for a new Z′ gauge boson in 4μ events with the ATLAS experiment

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    This paper presents a search for a new Z′ vector gauge boson with the ATLAS experiment at the Large Hadron Collider using pp collision data collected at s√ = 13 TeV, corresponding to an integrated luminosity of 139 fb−1. The new gauge boson Z′ is predicted by Lμ − Lτ models to address observed phenomena that can not be explained by the Standard Model. The search examines the four-muon (4μ) final state, using a deep learning neural network classifier to separate the Z′ signal from the Standard Model background events. The di-muon invariant masses in the 4μ events are used to extract the Z′ resonance signature. No significant excess of events is observed over the predicted background. Upper limits at a 95% confidence level on the Z′ production cross-section times the decay branching fraction of pp → Z′μμ → 4μ are set from 0.31 to 4.3 fb for the Z′ mass ranging from 5 to 81 GeV. The corresponding common coupling strengths, gZ′, of the Z′ boson to the second and third generation leptons above 0.003 – 0.2 have been excluded

    A search for heavy Higgs bosons decaying into vector bosons in same-sign two-lepton final states in pp collisions at s√ = 13 TeV with the ATLAS detector

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    A search for heavy Higgs bosons produced in association with a vector boson and decaying into a pair of vector bosons is performed in final states with two leptons (electrons or muons) of the same electric charge, missing transverse momentum and jets. A data sample of proton–proton collisions at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018 is used. The data correspond to a total integrated luminosity of 139 fb−1. The observed data are in agreement with Standard Model background expectations. The results are interpreted using higher-dimensional operators in an effective field theory. Upper limits on the production cross-section are calculated at 95% confidence level as a function of the heavy Higgs boson’s mass and coupling strengths to vector bosons. Limits are set in the Higgs boson mass range from 300 to 1500 GeV, and depend on the assumed couplings. The highest excluded mass for a heavy Higgs boson with the coupling combinations explored is 900 GeV. Limits on coupling strengths are also provided

    Counselling work in normal general practice: An analysis of Australian consultations.

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    As counselling is potentially an area of overlap between the functions of medical practitioners and of clinical health psychologists, it is important to know exactly what counselling encompasses in primary health care. A set of 68 counselling consultations were identified from collected transcripts of normal general practice work; seven representative examples are described and analysed in this article. The major purpose of three consultations was for the general practitioner (GP) to help the patient with psychological illness or behaviour disorder, and the question of most interest was how the parties negotiated this topic and how the GPs provided help. In four other consultations the major purpose was for the GP to answer the patient's questions. The results have implications for the delivery of primary health care and the work satisfaction of GPs, as well as for the collaborative relationships which may develop between GPs and clinical health psychologists
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