2,708 research outputs found

    Standards for Analysis of Ce, La, Pb, Rb, Se, Sr, Y, AND Zr in Rock Samples Using Laser-induced Breakdown Spectroscopy and X-ray Fluorescence

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    Analytical geochemistry has long depended on the availability of robust suites of rock standards with well-characterized compositions. Standard rock powders for wet chemistry and x-ray fluorescence were initially characterized and supplied to the community by the U.S. Geological Survey, which continues to distribute a few dozen standards. Many other rock standards have subsequently been developed by organizations such as the Centre de Recherches Ptrographiques et Gochimiques (CRPG) and Brammer Standard Company, Inc

    Integration and continuity of primary care: polyclinics and alternatives - a patient-centred analysis of how organisation constrains care co-ordination

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    Background An ageing population, the increasing specialisation of clinical services and diverse health-care provider ownership make the co-ordination and continuity of complex care increasingly problematic. The way in which the provision of complex health care is co-ordinated produces – or fails to produce – six forms of continuity of care (cross-sectional, longitudinal, flexible, access, informational and relational). Care co-ordination is accomplished by a combination of activities by patients themselves; provider organisations; care networks co-ordinating the separate provider organisations; and overall health-system governance. This research examines how far organisational integration might promote care co-ordination at the clinical level. Objectives To examine (1) what differences the organisational integration of primary care makes, compared with network governance, to horizontal and vertical co-ordination of care; (2) what difference provider ownership (corporate, partnership, public) makes; (3) how much scope either structure allows for managerial discretion and ‘performance’; (4) differences between networked and hierarchical governance regarding the continuity and integration of primary care; and (5) the implications of the above for managerial practice in primary care. Methods Multiple-methods design combining (1) the assembly of an analytic framework by non-systematic review; (2) a framework analysis of patients’ experiences of the continuities of care; (3) a systematic comparison of organisational case studies made in the same study sites; (4) a cross-country comparison of care co-ordination mechanisms found in our NHS study sites with those in publicly owned and managed Swedish polyclinics; and (5) the analysis and synthesis of data using an ‘inside-out’ analytic strategy. Study sites included professional partnership, corporate and publicly owned and managed primary care providers, and different configurations of organisational integration or separation of community health services, mental health services, social services and acute inpatient care. Results Starting from data about patients’ experiences of the co-ordination or under-co-ordination of care, we identified five care co-ordination mechanisms present in both the integrated organisations and the care networks; four main obstacles to care co-ordination within the integrated organisations, of which two were also present in the care networks; seven main obstacles to care co-ordination that were specific to the care networks; and nine care co-ordination mechanisms present in the integrated organisations. Taking everything into consideration, integrated organisations appeared more favourable to producing continuities of care than did care networks. Network structures demonstrated more flexibility in adding services for small care groups temporarily, but the expansion of integrated organisations had advantages when adding new services on a longer term and a larger scale. Ownership differences affected the range of services to which patients had direct access; primary care doctors’ managerial responsibilities (relevant to care co-ordination because of their impact on general practitioner workload); and the scope for doctors to develop special interests. We found little difference between integrated organisations and care networks in terms of managerial discretion and performance. Conclusions On balance, an integrated organisation seems more likely to favour the development of care co-ordination and, therefore, continuities of care than a system of care networks. At least four different variants of ownership and management of organisationally integrated primary care providers are practicable in NHS-like settings. Future research is therefore required, above all to evaluate comparatively the different techniques for coordinating patient discharge across the triple interface between hospitals, general practices and community health services; and to discover what effects increasing the scale and scope of general practice activities will have on continuity of care

    Quality indicators as a tool in improving the introduction of new medicines

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    Quality indicators are increasingly used as a tool to achieve safe and quality clinical care, cost-effective therapy, for professional learning, remuneration, accreditation and financial incentives. A substantial number focus on drug therapy but few address the introduction of new medicines even though this is a burning issue. The objective was to describe the issues and challenges in designing and implementing a transparent indicator framework and evaluation protocol for the introduction of new medicines and to provide guidance on how to apply quality indicators in the managed entry of new medicines. Quality indicators need to be developed early to assess whether new medicines are introduced appropriately. A number of key factors need to be addressed when developing, applying and evaluating indicators including dimensions of quality, suggested testing protocols, potential data sources, key implementation factors such as intended and unintended consequences, budget impact and cost-effectiveness, assuring the involvement of the medical professions, patients and the public, and reliable and easy-to-use computerized tools for data collection and management. Transparent approaches include the need for any quality indicators developed to handle conflict of interests to enhance their validity and acceptance. The suggested framework and indicator testing protocol may be useful in assessing the applicability of indicators for new medicines and may be adapted to healthcare settings worldwide. The suggestions build on existing literature to create a field testing methodology that can be used to produce country-specific quality indicators for new medicines as well as a cross international approach to facilitate access to new medicines

    Measurement of the Forward-Backward Asymmetry in the B -> K(*) mu+ mu- Decay and First Observation of the Bs -> phi mu+ mu- Decay

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    We reconstruct the rare decays B+→K+μ+μ−B^+ \to K^+\mu^+\mu^-, B0→K∗(892)0μ+μ−B^0 \to K^{*}(892)^0\mu^+\mu^-, and Bs0→ϕ(1020)μ+μ−B^0_s \to \phi(1020)\mu^+\mu^- in a data sample corresponding to 4.4fb−14.4 {\rm fb^{-1}} collected in ppˉp\bar{p} collisions at s=1.96TeV\sqrt{s}=1.96 {\rm TeV} by the CDF II detector at the Fermilab Tevatron Collider. Using 121±16121 \pm 16 B+→K+μ+μ−B^+ \to K^+\mu^+\mu^- and 101±12101 \pm 12 B0→K∗0μ+μ−B^0 \to K^{*0}\mu^+\mu^- decays we report the branching ratios. In addition, we report the measurement of the differential branching ratio and the muon forward-backward asymmetry in the B+B^+ and B0B^0 decay modes, and the K∗0K^{*0} longitudinal polarization in the B0B^0 decay mode with respect to the squared dimuon mass. These are consistent with the theoretical prediction from the standard model, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the Bs0→ϕμ+μ−decayandmeasureitsbranchingratioB^0_s \to \phi\mu^+\mu^- decay and measure its branching ratio {\mathcal{B}}(B^0_s \to \phi\mu^+\mu^-) = [1.44 \pm 0.33 \pm 0.46] \times 10^{-6}using using 27 \pm 6signalevents.Thisiscurrentlythemostrare signal events. This is currently the most rare B^0_s$ decay observed.Comment: 7 pages, 2 figures, 3 tables. Submitted to Phys. Rev. Let

    Search for a New Heavy Gauge Boson Wprime with Electron + missing ET Event Signature in ppbar collisions at sqrt(s)=1.96 TeV

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    We present a search for a new heavy charged vector boson W′W^\prime decaying to an electron-neutrino pair in ppˉp\bar{p} collisions at a center-of-mass energy of 1.96\unit{TeV}. The data were collected with the CDF II detector and correspond to an integrated luminosity of 5.3\unit{fb}^{-1}. No significant excess above the standard model expectation is observed and we set upper limits on σ⋅B(W′→eν)\sigma\cdot{\cal B}(W^\prime\to e\nu). Assuming standard model couplings to fermions and the neutrino from the W′W^\prime boson decay to be light, we exclude a W′W^\prime boson with mass less than 1.12\unit{TeV/}c^2 at the 95\unit{%} confidence level.Comment: 7 pages, 2 figures Submitted to PR

    Measurements of the properties of Lambda_c(2595), Lambda_c(2625), Sigma_c(2455), and Sigma_c(2520) baryons

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    We report measurements of the resonance properties of Lambda_c(2595)+ and Lambda_c(2625)+ baryons in their decays to Lambda_c+ pi+ pi- as well as Sigma_c(2455)++,0 and Sigma_c(2520)++,0 baryons in their decays to Lambda_c+ pi+/- final states. These measurements are performed using data corresponding to 5.2/fb of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. Exploiting the largest available charmed baryon sample, we measure masses and decay widths with uncertainties comparable to the world averages for Sigma_c states, and significantly smaller uncertainties than the world averages for excited Lambda_c+ states.Comment: added one reference and one table, changed order of figures, 17 pages, 15 figure

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    X-ray emission from the Sombrero galaxy: discrete sources

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    We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

    Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

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    The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO
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