1,993 research outputs found

    State Primary Stroke Center Policies in the US: Rural Health Issues.

    Get PDF
    Objective: To explore the relationship between state primary stroke center (PSC) designation policy implementation and access to optimal stroke care for residents of rural areas. Materials and Methods: Primary data were collected during the period September 2008–August 2009. Following content analysis of state PSC policies, four case study states were selected for fieldwork, in part for state rural healthcare access challenges. Variables included the barriers and facilitators to PSC designation policy implementation. More than 100 semistructured stakeholder interviews were conducted by teams of researchers. Large-group meetings were also observed. Interview summaries were reviewed by stakeholders for accuracy and completeness. Results: The consistent finding in all study states was that PSC designation and state policy implementation in rural areas are unlikely for a variety of reasons, including lack of financial resources for telemedicine, difficulty maintaining neurology coverage, and emergency departments unable to administer thrombolytics. Findings indicate recognition by states about the need for stroke-care public policy specific to telemedicine in rural areas. Conclusions: Although state PSC designation policies raise awareness of rural issues, designation policy alone cannot overcome the obstacle of rural access to optimal stroke care. States must be technology-ready, and providers need to embrace e-health and telemedicine to ensure coordination of care for stroke victims in rural areas. More important is that state policy makers should provide rules and regulations to encourage PSC hospitals to use telemedicine and “proxy credentialing” to support their affiliated rural facilitie

    Radiative neutron capture on a proton at BBN energies

    Full text link
    The total cross section for radiative neutron capture on a proton, np→dÎłnp \to d \gamma, is evaluated at big bang nucleosynthesis (BBN) energies. The electromagnetic transition amplitudes are calculated up to next-to leading order within the framework of pionless effective field theory with dibaryon fields. We also calculate the dγ→npd\gamma\to np cross section and the photon analyzing power for the dγ⃗→npd\vec{\gamma}\to np process from the amplitudes. The values of low energy constants that appear in the amplitudes are estimated by a Markov Chain Monte Carlo analysis using the relevant low energy experimental data. Our result agrees well with those of other theoretical calculations except for the np→dÎłnp\to d\gamma cross section at some energies estimated by an R-matrix analysis. We also study the uncertainties in our estimation of the np→dÎłnp\to d\gamma cross section at relevant BBN energies and find that the estimated cross section is reliable to within ∌\sim1% error.Comment: 21 pages and 12 eps figures; 6 eps figures and 2 references added, and accepted for publication in Phys. Rev.

    Magnetic properties of pure and Gd doped EuO probed by NMR

    Full text link
    An Eu NMR study in the ferromagnetic phase of pure and Gd doped EuO was performed. A complete description of the NMR lineshape of pure EuO allowed for the influence of doping EuO with Gd impurities to be highlighted. The presence of a temperature dependent static magnetic inhomogeneity in Gd doped EuO was demonstrated by studying the temperature dependence of the lineshapes. The results suggest that the inhomogeneity in 0.6% Gd doped EuO is linked to colossal magnetoresistance. The measurement of the spin-lattice relaxation times as a function of temperature led to the determination of the value of the exchange integral J as a function of Gd doping. It was found that J is temperature independent and spatially homogeneous for all the samples and that its value increases abruptly with increasing Gd doping.Comment: 14 pages, 10 figures, to be published in Physical Review

    The Instanton Molecule Liquid and "Sticky Molasses" Above T_c

    Full text link
    The main objective of this work is to explore the evolution in the structure of the quark-antiquark bound states in going down in the chirally restored phase from the so-called "zero binding points" T_zb to the QCD critical temperature T_c at which the Nambu-Goldstone and Wigner-Weyl modes meet. In doing this, we adopt the idea recently introduced by Shuryak and Zahed for charmed cˉc\bar c c, light-quark qˉq\bar q q mesons π,σ,ρ,A1\pi, \sigma, \rho, A_1 and gluons that at T_zb, the quark-antiquark scattering length goes through infinity at which conformal invariance is restored, thereby transforming the matter into a near perfect fluid behaving hydrodynamically, as found at RHIC. We show that the binding of these states is accomplished by the combination of (i) the color Coulomb interaction, (ii) the relativistic effects, and (iii) the interaction induced by the instanton-anti-instanton molecules. The spin-spin forces turned out to be small. While near T_zb all mesons are large-size nonrelativistic objects bound by Coulomb attraction, near T_c they get much more tightly bound, with many-body collective interactions becoming important and making the σ\sigma and π\pi masses approach zero (in the chiral limit). The wave function at the origin grows strongly with binding, and the near-local four-Fermi interactions induced by the instanton molecules play an increasingly more important role as the temperature moves downward toward T_c.Comment: Contribution to QM2004 proceedings, 4 page

    Radiative Neutron-Proton Capture in Effective Chiral Lagrangians

    Get PDF
    We calculate the cross-section for the thermal n+p→d+Îłn+p\rightarrow d+\gamma process in chiral perturbation theory to next-to-next-to-leading order using heavy-fermion formalism. The exchange current correction is found to be (4.5±0.3) %(4.5\pm 0.3)~\% in amplitude and the chiral perturbation at one-loop order gives the cross section \sigma_{th}^{np}=(334\pm 2)\ {\mbox mb} which is in agreement with the experimental value (334.2\pm 0.5)\ {\mbox mb}. Together with the axial charge transitions, this provides a strong support for the power of chiral Lagrangians for nuclear physics.Comment: 9 pages, revtex, uses epsfig.sty, 2 uuencoded figure

    Low-momentum Pion Enhancement Induced by Chiral Symmetry Restoration

    Full text link
    The thermal and nonthermal pion production by sigma decay and its relation with chiral symmetry restoration in a hot and dense matter are investigated. The nonthermal decay into pions of sigma mesons which are popularly produced in chiral symmetric phase leads to a low-momentum pion enhancement as a possible signature of chiral phase transition at finite temperature and density.Comment: 3 pages, 2 figure

    Exchange Current Corrections to Neutrino--Nucleus Scattering

    Get PDF
    Relativistic exchange current corrections to neutrino--nucleus cross sections are presented assuming non--vanishing strange quark form factors for the constituent nucleons. For charged current processes the exchange current corrections can lower the impulse approximation results by 10\% while these corrections are found to be sensitive to both the nuclear density and the strange quark axial form factor of the nucleon for neutral current processes. Implications on the LSND experiment to determine this form factor are discussed.Comment: 11 pages, 2 figures, revtex 3.0, full postscript version of the file and figures available at http://www.nikhefk.nikhef.nl/projects/Theory/preprints/preprints.html To appear in Phys. Rev. Lett
    • 

    corecore