375 research outputs found

    An Examination of Caregiving Dyads: Community Dwelling Chronically Ill Older Adults and Their Caregivers

    Get PDF
    Increases in life expectancy among older adults raise important concerns about the availability of resources for an aging population living with chronic and debilitating illnesses. Living longer is complicated by the fact that many elders prefer to reside in their homes until medical or other conditions require an alternative living arrangement. The strong desire to remain at home expressed by older persons in the United States has in turn created an increased demand on informal caregiving. Consequently, adult children often bear the burden of providing care to their aging parents. In view of this demand it is critical that research be conducted to identify the conditions that may threaten the stability of long-term caregiving arrangements. The purpose of this study was to examine the nature of interpersonal dynamics between caregivers and carereceivers during the care process. Specifically, the study aimed to investigate the relationship between role engagement and quality of commitment among caregivers and care-receivers and to assess how these two processes impact the psychological well-being of such dyads. A sample of caregiver and care-receiver dyads as well as additional caregivers were identified through Colorado agencies that administer home and community-based Medicaid programs and used to evaluate relationships between dyad members. Higher caregiver personal commitment to their care-receiver was related to care-receivers‘ experience of dyad strain. Caregiver perception of care-receiver competence had a negative relationship with care-receiver depression. Higher personal commitment in care-receivers was positively related to caregiver autonomy. Higher care-receiver relational coping was related to lower levels of caregiver dyad strain and depression. Personal commitment and perceived role competence of the care-receiver were significantly related to depression in caregivers. Like care-receivers, caregivers with higher levels of personal commitment also had lower levels of depression and lower dyad strain, higher positive interaction, and higher perception of care-receiver competence. Caregiver personal commitment and perceived role competence of care-receivers were significantly associated with depression in caregivers. Results indicate that personal and moral commitment may be important predictors of psychological well-being. Study findings that inform existing practice and policy strategies for older adults and their caregivers are discussed

    Kinetic Heterogeneities at Dynamical Crossovers

    Full text link
    We perform molecular dynamics simulations of a model glass-forming liquid to measure the size of kinetic heterogeneities, using a dynamic susceptibility χss(a,t)\chi_{\rm ss}(a, t) that quantifies the number of particles whose dynamics are correlated on the length scale aa and time scale tt. By measuring χss(a,t)\chi_{\rm ss}(a, t) as a function of both aa and tt, we locate local maxima χ\chi^\star at distances aa^\star and times tt^\star. Near the dynamical glass transition, we find two types of maxima, both correlated with crossovers in the dynamical behavior: a smaller maximum corresponding to the crossover from ballistic to sub-diffusive motion, and a larger maximum corresponding to the crossover from sub-diffusive to diffusive motion. Our results indicate that kinetic heterogeneities are not necessarily signatures of an impending glass or jamming transition.Comment: 6 pages, 4 figure

    Atomic Parity Nonconservation and Nuclear Anapole Moments

    Get PDF
    Anapole moments are parity-odd, time-reversal-even moments of the E1 projection of the electromagnetic current. Although it was recognized, soon after the discovery of parity violation in the weak interaction, that elementary particles and composite systems like nuclei must have anapole moments, it proved difficult to isolate this weak radiative correction. The first successful measurement, an extraction of the nuclear anapole moment of 133Cs from the hyperfine dependence of the atomic parity violation, was obtained only recently. An important anapole moment bound in Tl also exists. We discuss these measurements and their significance as tests of the hadronic weak interaction, focusing on the mechanisms that operate within the nucleus to generate the anapole moment. The atomic results place new constraints on weak meson-nucleon couplings, ones we compare to existing bounds from a variety of p-p and nuclear tests of parity nonconservation.Comment: 35 pages; 8 figures; late

    Nuclear Spin-Isospin Correlations, Parity Violation, and the fπf_\pi Problem

    Get PDF
    The strong interaction effects of isospin- and spin-dependent nucleon-nucleon correlations observed in many-body calculations are interpreted in terms of a one-pion exchange mechanism. Including such effects in computations of nuclear parity violating effects leads to enhancements of about 10%. A larger effect arises from the one-boson exchange nature of the parity non-conserving nucleon- nucleon interaction, which depends on both weak and strong meson-nucleon coupling constants. Using values of the latter that are constrained by nucleon-nucleon phase shifts leads to enhancements of parity violation by factors close to two. Thus much of previously noticed discrepancies between weak coupling constants extracted from different experiments can be removed.Comment: 8 pages 2 figures there should have been two figures in v

    Beyond the Shell Model: The Canonical Nuclear Many-Body Problem as an Effective Theory

    Get PDF
    We describe a strategy for attacking the canonical nuclear structure problem ---bound-state properties of a system of point nucleons interacting via a two-body potential---which involves an expansion in the number of particles scattering at high momenta, but is otherwise exact. The required self-consistent solutions of the Bloch-Horowitz equation for effective interactions and operators are obtained by an efficient Green's function method based on the Lanczos algorithm. We carry out this program for the simplest nuclei, d and 3^3He, to contrast a rigorous effective theory with the shell model, thereby illustrating several of the uncontrolled approximations in the latter.Comment: Revtex; two columns; four pages; two figures; submitted to Phys. Rev. Let

    Anapole Moment and Other Constraints on the Strangeness Conserving Hadronic Weak Interaction

    Get PDF
    Standard analyses of low-energy NN and nuclear parity-violating observables have been based on a pi-, rho-, and omega-exchange model capable of describing all five independent s-p partial waves. Here a parallel analysis is performed for the one-body, exchange-current, and nuclear polarization contributions to the anapole moments of 133Cs and 205Tl. The resulting constraints are not consistent, though there remains some degree of uncertainty in the nuclear structure analysis of the atomic moments.Comment: Revtex, 10 pages, 1 figur

    Measuring the νμ\nu_{\mu} to νμˉ\bar{\nu_{\mu}} Ratio in a High Statistics Atmospheric Neutrino Experiment

    Full text link
    By exploiting differences in muon lifetimes it is possible to distinguish νμ\nu_{\mu} from νμˉ\bar{\nu_{\mu}} charged current interactions in underground neutrino detectors. Such observations would be a useful tool in understanding the source of the atmospheric neutrino anomaly.Comment: 6 pages no figure

    Constraints on Parity-Even Time Reversal Violation in the Nucleon-Nucleon System and Its Connection to Charge Symmetry Breaking

    Full text link
    Parity-even time reversal violation (TRV) in the nucleon-nucleon interaction is reconsidered. The TRV ρ\rho-exchange interaction on which recent analyses of measurements are based is necessarily also charge-symmetry breaking (CSB). Limits on its strength gˉρ\bar{g}_\rho relative to regular ρ\rho-exchange are extracted from recent CSB experiments in neutron-proton scattering. The result gˉρ6.7×103\bar{g}_\rho\le 6.7\times 10^{-3} (95% CL) is considerably lower than limits inferred from direct TRV tests in nuclear processes. Properties of a1a_1-exchange and limit imposed by the neutron EDM are briefly discussed.Comment: RevTex, 8 pages. Factor ten error in cited neutron EDM corrected, discussion and two references adde
    corecore