1,577 research outputs found

    A methodology for setting practice criteria in healthcare

    Get PDF
    Practice criteria are an important part of health care and have taken a new prominence in the trend to address quality-of-care issues. Once an organisation makes a commitment to addressing its quality-of- care, it must define 'quality' in operational terms. Practice criteria do just that. The organisation ensures consistent, high-quality services through the correct application of practice criteria. This paper outlines a methodology that has been used in at least three countries to date. Early indications are that it is useful for helping an organisation begin its quality improvement 'journey'.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Systematic thermal reduction of neutronization in core-collapse supernovae

    Full text link
    We investigate to what extent the temperature dependence of the nuclear symmetry energy can affect the neutronization of the stellar core prior to neutrino trapping during gravitational collapse. To this end, we implement a one-zone simulation to follow the collapse until beta equilibrium is reached and the lepton fraction remains constant. Since the strength of electron capture on the neutron-rich nuclei associated to the supernova scenario is still an open issue, we keep it as a free parameter. We find that the temperature dependence of the symmetry energy consistently yields a small reduction of deleptonization, which corresponds to a systematic effect on the shock wave energetics: the gain in dissociation energy of the shock has a small yet non-negligible value of about 0.4 foe (1 foe = 10^51 erg) and this result is almost independent from the strength of nuclear electron capture. The presence of such a systematic effect and its robustness under changes of the parameters of the one-zone model are significative enough to justify further investigations with detailed numerical simulations of supernova explosions.Comment: 15 pages, 2 tables, 3 figure

    Magnetic dipole probes of the sd and pf shell crossing in the A=36,38 argon isotopes

    Full text link
    We have calculated the M1 strength distributions in the A=36,38 argon isotopes within large-scale shell model studies which consider valence nucleons in the sd and pf shells. While the M1 strength in 36Ar is well reproduced within the sd shell, the experimentally observed strong fragmentation of the M1 strength in 38Ar requires configuration mixing between the sd and the pf shells adding to our understanding of correlations across the N=20 shell gap.Comment: 14 pages, 8 figure

    Peculiarities of the stochastic motion in antiferromagnetic nanoparticles

    Full text link
    Antiferromagnetic (AFM) materials are widely used in spintronic devices as passive elements (for stabilization of ferromangetic layers) and as active elements (for information coding). In both cases switching between the different AFM states depends in a great extent from the environmental noise. In the present paper we derive the stochastic Langevin equations for an AFM vector and corresponding Fokker-Planck equation for distribution function in the phase space of generalised coordinate and momentum. Thermal noise is modeled by a random delta-correlated magnetic field that interacts with the dynamic magnetisation of AFM particle. We analyse in details a particular case of the collinear compensated AFM in the presence of spin-polarised current. The energy distribution function for normal modes in the vicinity of two equilibrium states (static and stationary) in sub- and super-critical regimes is found. It is shown that the noise-induced dynamics of AFM vector has pecuilarities compared to that of magnetisation vector in ferromagnets.Comment: Submitted to EPJ ST, presented at the 4-th Conference on Statistical Physics, Lviv, Ukraine, 201

    Propagator of a Charged Particle with a Spin in Uniform Magnetic and Perpendicular Electric Fields

    Full text link
    We construct an explicit solution of the Cauchy initial value problem for the time-dependent Schroedinger equation for a charged particle with a spin moving in a uniform magnetic field and a perpendicular electric field varying with time. The corresponding Green function (propagator) is given in terms of elementary functions and certain integrals of the fields with a characteristic function, which should be found as an analytic or numerical solution of the equation of motion for the classical oscillator with a time-dependent frequency. We discuss a particular solution of a related nonlinear Schroedinger equation and some special and limiting cases are outlined.Comment: 17 pages, no figure

    The Hyperfine Spin Splittings In Heavy Quarkonia

    Get PDF
    The hyperfine spin splittings in heavy quarkonia are studied using the recently developed renormalization group improved spin-spin potential which is independent of the scale parameter μ\mu. The calculated energy difference between the J/ψJ/\psi and the ηc\eta_c fits the experimental data well, while the predicted energy difference ΔMp\Delta M_p between the center of the gravity of 13P0,1,21^3P_{0,1,2} states and the 11P11^1P_1 state of charmonium has the correct sign but is somewhat larger than the experimental data. This is not surprising since there are several other contributions to ΔMp\Delta M_p, which we discuss, that are of comparable size (1\sim 1 MeV) that should be included, before precise agreement with the data can be expected. The mass differences of the ψηc\psi'-\eta_c', Υ(1S)ηb\Upsilon(1S)-\eta_b, Υ(2S)ηb\Upsilon(2S)-\eta_b', and BcBcB_c^*-B_c are also predicted.Comment: 17 page

    Interleukin-7 deficiency in rheumatoid arthritis: consequences for therapy-induced lymphopenia

    Get PDF
    We previously demonstrated prolonged, profound CD4+ T-lymphopenia in rheumatoid arthritis (RA) patients following lymphocyte-depleting therapy. Poor reconstitution could result either from reduced de novo T-cell production through the thymus or from poor peripheral expansion of residual T-cells. Interleukin-7 (IL-7) is known to stimulate the thymus to produce new T-cells and to allow circulating mature T-cells to expand, thereby playing a critical role in T-cell homeostasis. In the present study we demonstrated reduced levels of circulating IL-7 in a cross-section of RA patients. IL-7 production by bone marrow stromal cell cultures was also compromised in RA. To investigate whether such an IL-7 deficiency could account for the prolonged lymphopenia observed in RA following therapeutic lymphodepletion, we compared RA patients and patients with solid cancers treated with high-dose chemotherapy and autologous progenitor cell rescue. Chemotherapy rendered all patients similarly lymphopenic, but this was sustained in RA patients at 12 months, as compared with the reconstitution that occurred in cancer patients by 3–4 months. Both cohorts produced naïve T-cells containing T-cell receptor excision circles. The main distinguishing feature between the groups was a failure to expand peripheral T-cells in RA, particularly memory cells during the first 3 months after treatment. Most importantly, there was no increase in serum IL-7 levels in RA, as compared with a fourfold rise in non-RA control individuals at the time of lymphopenia. Our data therefore suggest that RA patients are relatively IL-7 deficient and that this deficiency is likely to be an important contributing factor to poor early T-cell reconstitution in RA following therapeutic lymphodepletion. Furthermore, in RA patients with stable, well controlled disease, IL-7 levels were positively correlated with the T-cell receptor excision circle content of CD4+ T-cells, demonstrating a direct effect of IL-7 on thymic activity in this cohort
    corecore