594 research outputs found

    Association of Primary Care Physician Supply with Population Mortality in the United States, 2005-2015

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    Importance: Recent US health care reforms incentivize improved population health outcomes and primary care functions. It remains unclear how much improving primary care physician supply can improve population health, independent of other health care and socioeconomic factors. Objectives: To identify primary care physician supply changes across US counties from 2005-2015 and associations between such changes and population mortality. Design, Setting, and Participants: This epidemiological study evaluated US population data and individual-level claims data linked to mortality from 2005 to 2015 against changes in primary care and specialist physician supply from 2005 to 2015. Data from 3142 US counties, 7144 primary care service areas, and 306 hospital referral regions were used to investigate the association of primary care physician supply with changes in life expectancy and cause-specific mortality after adjustment for health care, demographic, socioeconomic, and behavioral covariates. Analysis was performed from March to July 2018. Main Outcomes and Measures: Age-standardized life expectancy, cause-specific mortality, and restricted mean survival time. Results: Primary care physician supply increased from 196014 physicians in 2005 to 204419 in 2015. Owing to disproportionate losses of primary care physicians in some counties and population increases, the mean (SD) density of primary care physicians relative to population size decreased from 46.6 per 100000 population (95% CI, 0.0-114.6 per 100000 population) to 41.4 per 100000 population (95% CI, 0.0-108.6 per 100000 population), with greater losses in rural areas. In adjusted mixed-effects regressions, every 10 additional primary care physicians per 100000 population was associated with a 51.5-day increase in life expectancy (95% CI, 29.5-73.5 days; 0.2% increase), whereas an increase in 10 specialist physicians per 100000 population corresponded to a 19.2-day increase (95% CI, 7.0-31.3 days). A total of 10 additional primary care physicians per 100000 population was associated with reduced cardiovascular, cancer, and respiratory mortality by 0.9% to 1.4%. Analyses at different geographic levels, using instrumental variable regressions, or at the individual level found similar benefits associated with primary care supply. Conclusions and Relevance: Greater primary care physician supply was associated with lower mortality, but per capita supply decreased between 2005 and 2015. Programs to explicitly direct more resources to primary care physician supply may be important for population health

    A 31-day time to surgery compliant exercise training programme improves aerobic health in the elderly

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    Background: Over 41,000 people were diagnosed with colorectal cancer (CRC) in the UK in 2011. The incidence of CRC increases with age. Many elderly patients undergo surgery for CRC, the only curative treatment. Such patients are exposed to risks, which increase with age and reduced physical fitness. Endurance-based exercise training programmes can improve physical fitness, but such programmes do not comply with the UK, National Cancer Action Team 31-day time-to-treatment target. High-intensity interval training (HIT) can improve physical performance within 2–4 weeks, but few studies have shown HIT to be effective in elderly individuals, and those who do employ programmes longer than 31 days. Therefore, we investigated whether HIT could improve cardiorespiratory fitness in elderly volunteers, age-matched to a CRC population, within 31 days. Methods: This observational cohort study recruited 21 healthy elderly participants (8 male and 13 female; age 67 years (range 62–73 years)) who undertook cardiopulmonary exercise testing before and after completing 12 sessions of HIT within a 31-day period. Results: Peak oxygen consumption (VO2 peak) (23.9 ± 4.7 vs. 26.2 ± 5.4 ml/kg/min, p = 0.0014) and oxygen consumption at anaerobic threshold (17.86 ± 4.45 vs. 20.21 ± 4.11 ml/kg/min, p = 0.008) increased after HIT. Conclusions: It is possible to improve cardiorespiratory fitness in 31 days in individuals of comparable age to those presenting for CRC surgery

    Absolute Calibration of a 200 MeV Proton Polarimeter for Use with the Brookhaven Linac

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    This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit

    An ansatz for the nonlinear Demkov-Kunike problem for cold molecule formation

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    We study nonlinear mean-field dynamics of ultracold molecule formation in the case when the external field configuration is defined by the level-crossing Demkov-Kunike model, characterized by a bell-shaped coupling and finite variation of the detuning. Analyzing the fast sweep rate regime of the strong interaction limit, which models a situation when the peak value of the coupling is large enough and the resonance crossing is sufficiently fast, we construct a highly accurate ansatz to describe the temporal dynamics of the molecule formation in the mentioned interaction regime. The absolute error of the constructed approximation is less than 3*10^-6 for the final transition probability while at certain time points it might increase up to 10^-3. Examining the role of the different terms in the constructed approximation, we prove that in the fast sweep rate regime of the strong interaction limit the temporal dynamics of the atom-molecule conversion effectively consists of the process of resonance crossing, which is governed by a nonlinear equation, followed by atom-molecular coherent oscillations which are basically described by a solution of the linear problem, associated with the considered nonlinear one.Comment: Accepted for publication in J. Contemp. Phys. (Armenian National Academy of Sciences) 8 pages, 4 figure

    Stakeholder Theory and Marketing: Moving from a Firm-Centric to a Societal Perspective

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    This essay is inspired by the ideas and research examined in the special section on “Stakeholder Marketing” of the Journal of Public Policy & Marketing in 2010. The authors argue that stakeholder marketing is slowly coalescing with the broader thinking that has occurred in the stakeholder management and ethics literature streams during the past quarter century. However, the predominant view of stakeholders that many marketers advocate is still primarily pragmatic and company centric. The position advanced herein is that stronger forms of stakeholder marketing that reflect more normative, macro/societal, and network-focused orientations are necessary. The authors briefly explain and justify these characteristics in the context of the growing “prosociety” and “proenvironment” perspectives—orientations that are also in keeping with the public policy focus of this journal. Under the “hard form” of stakeholder theory, which the authors endorse, marketing managers must realize that serving stakeholders sometimes requires sacrificing maximum profits to mitigate outcomes that would inflict major damage on other stakeholders, especially society

    From nonwetting to prewetting: the asymptotic behavior of 4He drops on alkali substrates

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    We investigate the spreading of 4He droplets on alkali surfaces at zero temperature, within the frame of Finite Range Density Functional theory. The equilibrium configurations of several 4He_N clusters and their asymptotic trend with increasing particle number N, which can be traced to the wetting behavior of the quantum fluid, are examined for nanoscopic droplets. We discuss the size effects, inferring that the asymptotic properties of large droplets correspond to those of the prewetting film

    Effective theory of the Delta(1232) in Compton scattering off the nucleon

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    We formulate a new power-counting scheme for a chiral effective field theory of nucleons, pions, and Deltas. This extends chiral perturbation theory into the Delta-resonance region. We calculate nucleon Compton scattering up to next-to-leading order in this theory. The resultant description of existing γ\gammap cross section data is very good for photon energies up to about 300 MeV. We also find reasonable numbers for the spin-independent polarizabilities αp\alpha_p and βp\beta_p.Comment: 29 pp, 9 figs. Minor revisions. To be published in PR

    Impact of the calcium form of β-hydroxy-β-methylbutyrate upon human skeletal muscle protein metabolism

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    Background & aims: β-hydroxy-β-methylbutyrate (HMB) is purported as a key nutritional supplement for the preservation of muscle mass in health, disease and as an ergogenic aid in exercise. Of the two available forms of HMB (calcium (Ca-HMB) salt or free acid (FA-HMB)) – differences in plasma bioavailability have been reported. We previously reported that ∼3 g oral FA-HMB increased muscle protein synthesis (MPS) and reduced muscle protein breakdown (MPB). The objective of the present study was to quantify muscle protein metabolism responses to oral Ca-HMB. Methods: Eight healthy young males received a primed constant infusion of 1,2 13C2 leucine and 2H5 phenylalanine to assess MPS (by tracer incorporation in myofibrils) and MPB (via arterio-venous (A-V) dilution) at baseline and following provision of ∼3 g of Ca-HMB; muscle anabolic (MPS) and catabolic (MPB) signalling was assessed via immunoblotting. Results: Ca-HMB led a significant and rapid (<60 min) peak in plasma HMB concentrations (483.6 ± 14.2 μM, p < 0.0001). This rise in plasma HMB was accompanied by increases in MPS (PA: 0.046 ± 0.004%/h, CaHMB: 0.072 ± 0.004%/h, p < 0001) and suppressions in MPB (PA: 7.6 ± 1.2 μmol Phe per leg min−1, Ca-HMB: 5.2 ± 0.8 μmol Phe per leg min−1, p < 0.01). Increases in the phosphorylation of mTORc1 substrates i.e. p70S6K1 and RPS6 were also observed, with no changes detected in the MPB targets measured. Conclusions: These findings support the pro-anabolic properties of HMB via mTORc1, and show that despite proposed differences in bioavailability, Ca-HMB provides a comparable stimulation to MPS and suppression of MPB, to FA-HMB, further supporting its use as a pharmaconutrient in the modulation of muscle mass

    To wet or not to wet: that is the question

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    Wetting transitions have been predicted and observed to occur for various combinations of fluids and surfaces. This paper describes the origin of such transitions, for liquid films on solid surfaces, in terms of the gas-surface interaction potentials V(r), which depend on the specific adsorption system. The transitions of light inert gases and H2 molecules on alkali metal surfaces have been explored extensively and are relatively well understood in terms of the least attractive adsorption interactions in nature. Much less thoroughly investigated are wetting transitions of Hg, water, heavy inert gases and other molecular films. The basic idea is that nonwetting occurs, for energetic reasons, if the adsorption potential's well-depth D is smaller than, or comparable to, the well-depth of the adsorbate-adsorbate mutual interaction. At the wetting temperature, Tw, the transition to wetting occurs, for entropic reasons, when the liquid's surface tension is sufficiently small that the free energy cost in forming a thick film is sufficiently compensated by the fluid- surface interaction energy. Guidelines useful for exploring wetting transitions of other systems are analyzed, in terms of generic criteria involving the "simple model", which yields results in terms of gas-surface interaction parameters and thermodynamic properties of the bulk adsorbate.Comment: Article accepted for publication in J. Low Temp. Phy

    Signals for Lorentz Violation in Electrodynamics

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    An investigation is performed of the Lorentz-violating electrodynamics extracted from the renormalizable sector of the general Lorentz- and CPT-violating standard-model extension. Among the unconventional properties of radiation arising from Lorentz violation is birefringence of the vacuum. Limits on the dispersion of light produced by galactic and extragalactic objects provide bounds of 3 x 10^{-16} on certain coefficients for Lorentz violation in the photon sector. The comparative spectral polarimetry of light from cosmologically distant sources yields stringent constraints of 2 x 10^{-32}. All remaining coefficients in the photon sector are measurable in high-sensitivity tests involving cavity-stabilized oscillators. Experimental configurations in Earth- and space-based laboratories are considered that involve optical or microwave cavities and that could be implemented using existing technology.Comment: 23 pages REVTe
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