459 research outputs found
An Examination of Caregiving Dyads: Community Dwelling Chronically Ill Older Adults and Their Caregivers
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-receiversâ 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
We perform molecular dynamics simulations of a model glass-forming liquid to
measure the size of kinetic heterogeneities, using a dynamic susceptibility
that quantifies the number of particles whose dynamics
are correlated on the length scale and time scale . By measuring
as a function of both and , we locate local maxima
at distances and times . 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
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
Schiff Theorem and the Electric Dipole Moments of Hydrogen-Like Atoms
The Schiff theorem is revisited in this work and the residual - and
-odd electron--nucleus interaction, after the shielding takes effect, is
completely specified. An application is made to the electric dipole moments of
hydrogen-like atoms, whose qualitative features and systematics have important
implication for realistic paramagnetic atoms.Comment: 3 pages. Contribution to PANIC05, Particles and Nuclei International
Conference, Santa Fe, New Mexico, Oct. 24-28, 200
Nuclear Spin-Isospin Correlations, Parity Violation, and the Problem
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
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 He, 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
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
Effective Interactions for the Three-Body Problem
The three-body energy-dependent effective interaction given by the
Bloch-Horowitz (BH) equation is evaluated for various shell-model oscillator
spaces. The results are applied to the test case of the three-body problem
(triton and He3), where it is shown that the interaction reproduces the exact
binding energy, regardless of the parameterization (number of oscillator quanta
or value of the oscillator parameter b) of the low-energy included space. We
demonstrate a non-perturbative technique for summing the excluded-space
three-body ladder diagrams, but also show that accurate results can be obtained
perturbatively by iterating the two-body ladders. We examine the evolution of
the effective two-body and induced three-body terms as b and the size of the
included space Lambda are varied, including the case of a single included
shell, Lambda hw=0 hw. For typical ranges of b, the induced effective
three-body interaction, essential for giving the exact three-body binding, is
found to contribute ~10% to the binding energy.Comment: 19 pages, 9 figures, submitted to PR
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