322 research outputs found

    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

    Self-rated health of primary care house officers and its relationship to psychological and spiritual well-being

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    <p/> <p>Background</p> <p>The stress associated with residency training may place house officers at risk for poorer health. We sought to determine the level of self-reported health among resident physicians and to ascertain factors that are associated with their reported health.</p> <p>Methods</p> <p>A questionnaire was administered to house officers in 4 residency programs at a large Midwestern medical center. Self-rated health was determined by using a health rating scale (ranging from 0 = death to 100 = perfect health) and a Likert scale (ranging from "poor" health to "excellent" health). Independent variables included demographics, residency program type, post-graduate year level, current rotation, depressive symptoms, religious affiliation, religiosity, religious coping, and spirituality.</p> <p>Results</p> <p>We collected data from 227 subjects (92% response rate). The overall mean (SD) health rating score was 87 (10; range, 40–100), with only 4 (2%) subjects reporting a score of 100; on the Likert scale, only 88 (39%) reported excellent health. Lower health rating scores were significantly associated (P < 0.05) with internal medicine residency program, post-graduate year level, depressive symptoms, and poorer spiritual well-being. In multivariable analyses, lower health rating scores were associated with internal medicine residency program, depressive symptoms, and poorer spiritual well-being.</p> <p>Conclusion</p> <p>Residents' self-rated health was poorer than might be expected in a cohort of relatively young physicians and was related to program type, depressive symptoms, and spiritual well-being. Future studies should examine whether treating depressive symptoms and attending to spiritual needs can improve the overall health and well-being of primary care house officers.</p

    Spiritual Well-Being and Depression in Patients with Heart Failure

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    BACKGROUND: In patients with chronic heart failure, depression is common and associated with poor quality of life, more frequent hospitalizations, and higher mortality. Spiritual well-being is an important, modifiable coping resource in patients with terminal cancer and is associated with less depression, but little is known about the role of spiritual well-being in patients with heart failure. OBJECTIVE: To identify the relationship between spiritual well-being and depression in patients with heart failure. DESIGN: Cross-sectional study. PARTICIPANTS: Sixty patients aged 60 years or older with New York Heart Association class II–IV heart failure. MEASUREMENTS: Spiritual well-being was measured using the total scale and 2 subscales (meaning/peace, faith) of the Functional Assessment of Chronic Illness Therapy—Spiritual Well-being scale, depression using the Geriatric Depression Scale—Short Form (GDS-SF). RESULTS: The median age of participants was 75 years. Nineteen participants (32%) had clinically significant depression (GDS-SF > 4). Greater spiritual well-being was strongly inversely correlated with depression (Spearman’s correlation −0.55, 95% confidence interval −0.70 to −0.35). In particular, greater meaning/peace was strongly associated with less depression (r = −.60, P < .0001), while faith was only modestly associated (r = −.38, P < .01). In a regression analysis accounting for gender, income, and other risk factors for depression (social support, physical symptoms, and health status), greater spiritual well-being continued to be significantly associated with less depression (P = .05). Between the 2 spiritual well-being subscales, only meaning/peace contributed significantly to this effect (P = .02) and accounted for 7% of the variance in depression. CONCLUSIONS: Among outpatients with heart failure, greater spiritual well-being, particularly meaning/peace, was strongly associated with less depression. Enhancement of patients’ sense of spiritual well-being might reduce or prevent depression and thus improve quality of life and other outcomes in this population

    Axial and Radial Forces of Cross-Bridges Depend on Lattice Spacing

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    Nearly all mechanochemical models of the cross-bridge treat myosin as a simple linear spring arranged parallel to the contractile filaments. These single-spring models cannot account for the radial force that muscle generates (orthogonal to the long axis of the myofilaments) or the effects of changes in filament lattice spacing. We describe a more complex myosin cross-bridge model that uses multiple springs to replicate myosin's force-generating power stroke and account for the effects of lattice spacing and radial force. The four springs which comprise this model (the 4sXB) correspond to the mechanically relevant portions of myosin's structure. As occurs in vivo, the 4sXB's state-transition kinetics and force-production dynamics vary with lattice spacing. Additionally, we describe a simpler two-spring cross-bridge (2sXB) model which produces results similar to those of the 4sXB model. Unlike the 4sXB model, the 2sXB model requires no iterative techniques, making it more computationally efficient. The rate at which both multi-spring cross-bridges bind and generate force decreases as lattice spacing grows. The axial force generated by each cross-bridge as it undergoes a power stroke increases as lattice spacing grows. The radial force that a cross-bridge produces as it undergoes a power stroke varies from expansive to compressive as lattice spacing increases. Importantly, these results mirror those for intact, contracting muscle force production

    Projected Loss of a Salamander Diversity Hotspot as a Consequence of Projected Global Climate Change

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    Background: Significant shifts in climate are considered a threat to plants and animals with significant physiological limitations and limited dispersal abilities. The southern Appalachian Mountains are a global hotspot for plethodontid salamander diversity. Plethodontids are lungless ectotherms, so their ecology is strongly governed by temperature and precipitation. Many plethodontid species in southern Appalachia exist in high elevation habitats that may be at or near their thermal maxima, and may also have limited dispersal abilities across warmer valley bottoms. Methodology/Principal Findings: We used a maximum-entropy approach (program Maxent) to model the suitable climatic habitat of 41 plethodontid salamander species inhabiting the Appalachian Highlands region (33 individual species and eight species included within two species complexes). We evaluated the relative change in suitable climatic habitat for these species in the Appalachian Highlands from the current climate to the years 2020, 2050, and 2080, using both the HADCM3 and the CGCM3 models, each under low and high CO 2 scenarios, and using two-model thresholds levels (relative suitability thresholds for determining suitable/unsuitable range), for a total of 8 scenarios per species. Conclusion/Significance: While models differed slightly, every scenario projected significant declines in suitable habitat within the Appalachian Highlands as early as 2020. Species with more southern ranges and with smaller ranges had larger projected habitat loss. Despite significant differences in projected precipitation changes to the region, projections did no

    Motor signatures of emotional reactivity in frontotemporal dementia

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    Automatic motor mimicry is essential to the normal processing of perceived emotion, and disrupted automatic imitation might underpin socio-emotional deficits in neurodegenerative diseases, particularly the frontotemporal dementias. However, the pathophysiology of emotional reactivity in these diseases has not been elucidated. We studied facial electromyographic responses during emotion identification on viewing videos of dynamic facial expressions in 37 patients representing canonical frontotemporal dementia syndromes versus 21 healthy older individuals. Neuroanatomical associations of emotional expression identification accuracy and facial muscle reactivity were assessed using voxel-based morphometry. Controls showed characteristic profiles of automatic imitation, and this response predicted correct emotion identification. Automatic imitation was reduced in the behavioural and right temporal variant groups, while the normal coupling between imitation and correct identification was lost in the right temporal and semantic variant groups. Grey matter correlates of emotion identification and imitation were delineated within a distributed network including primary visual and motor, prefrontal, insular, anterior temporal and temporo-occipital junctional areas, with common involvement of supplementary motor cortex across syndromes. Impaired emotional mimesis may be a core mechanism of disordered emotional signal understanding and reactivity in frontotemporal dementia, with implications for the development of novel physiological biomarkers of socio-emotional dysfunction in these diseases

    Influence of country and city images on students’ perception of host universities and their satisfaction with the assigned destination for their exchange programmes

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    ABSTRACT: This research focuses on the effect that country image, city image and university image has on students’ a priori satisfaction with the assigned destination for their international exchange programme (Bachelor and Master). In particular, this study establishes six hypotheses related to the causal relationships among the different typologies of image and their effects on students’ satisfaction with the assigned destination to study at least one semester in a host university. In order to contrast these hypotheses, a quantitative research was carried out in the Spanish city of Santander (Spain), by obtaining a sample of 245 international students who participated in an exchange programme at the University of Cantabria. The research findings are: (1) students’ satisfaction with the assigned destination is positively influenced by the university image; (2) the university image is positively influenced by the city image; and (3) the city image is positively influenced by the country image

    Search for supersymmetry in events with opposite-sign dileptons and missing transverse energy using an artificial neural network

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    In this paper, a search for supersymmetry (SUSY) is presented in events with two opposite-sign isolated leptons in the final state, accompanied by hadronic jets and missing transverse energy. An artificial neural network is employed to discriminate possible SUSY signals from a standard model background. The analysis uses a data sample collected with the CMS detector during the 2011 LHC run, corresponding to an integrated luminosity of 4: 98 fb(-1) of proton-proton collisions at the center-of-mass energy of 7 TeV. Compared to other CMS analyses, this one uses relaxed criteria on missing transverse energy (E-T > 40 GeV) and total hadronic transverse energy (HT > 120 GeV), thus probing different regions of parameter space. Agreement is found between standard model expectation and observations, yielding limits in the context of the constrained minimal supersymmetric standard model and on a set of simplified models. DOI: 10.1103/PhysRevD.87.07200

    Search for new physics in events with same-sign dileptons and b jets in pp collisions at root s=8 TeV

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    A search for new physics is performed using events with isolated same-sign leptons and at least two bottom-quark jets in the final state. Results are based on a sample of proton-proton collisions collected at a center-of-mass energy of 8TeV with the CMS detector and corresponding to an integrated luminosity of 10.5 fb(-1). No excess above the standard model background is observed. Upper limits are set on the number of events from non-standard-model sources and are used to constrain a number of new physics models. Information on acceptance and efficiencies is also provided so that the results can be used to confront an even broader class of new physics models
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