5,794 research outputs found
Factors That Influence Self-Reported Health Changes With Caregiving
Objective: This study examined factors associated with the self-reported change in health status as a result of caregiving. Method: Multinomial logistic regression were performed to examine the sociodemographic characteristics, care recipients’ characteristics, and caregiving experiences that affect caregivers’ perceptions of health affected by caregiving using data from 1,087 caregiver respondents in the Caregiving in the U.S. 2015 data set. Data were collected through an online or telephone survey of randomly selected adults in 50 states. Results: Worsened self-reported health with caregiving occurred for caregivers aged 50 to 64, racial/ethnic minorities, those who lived within 20 min of the care recipient’s home, the presence of cognitive deficits, prolonged caregiving, and limited availability of accessible and affordable care services. Importantly, the feeling of choice in taking on care responsibilities was associated with an over fourfold increase in the odds ratio (OR) of better health in response to caregiving (OR = 4.21; confidence interval [CI] = [1.95, 9.08]; p \u3c .001). Discussion: Results suggest that improving accessibility of social service resources to assist caregivers in being better supported and having more choice in caregiving responsibilities may foster a positive change in health status with caregiving
Almost automorphic delayed differential equations and Lasota-Wazewska model
Existence of almost automorphic solutions for abstract delayed differential
equations is established. Using ergodicity, exponential dichotomy and Bi-almost
automorphicity on the homogeneous part, sufficient conditions for the existence
and uniqueness of almost automorphic solutions are given.Comment: 16 page
New patterns in steady-state chemical kinetics: intersections, coincidences, map of events (two-step mechanism)
New patterns of steady-state chemical kinetics for continuously stirred-tank reactors (CSTR) have been found, i.e., intersections, maxima and coincidences, for two-step mechanism ABC. There were found elegant analytical relationships for characteristics of these patterns (space times, values of concentrations and rates) allowing kinetic parameters to be easily determined. It was demonstrated that for the pair of species involved into the irreversible reaction (B and C), the space time of their corresponding concentration dependence intersection is invariant and does not depend on the initial conditions of the system. Maps of patterns are presented for visualization of their combinations and ranking in space time, and values of concentration and rates
A High-Fidelity Realization of the Euclid Code Comparison -body Simulation with Abacus
We present a high-fidelity realization of the cosmological -body
simulation from the Schneider et al. (2016) code comparison project. The
simulation was performed with our Abacus -body code, which offers high force
accuracy, high performance, and minimal particle integration errors. The
simulation consists of particles in a box,
for a particle mass of with $10\
h^{-1}\mathrm{kpc}z=0<0.3\%k<10\
\mathrm{Mpc}^{-1}h0.01\%$. Simulation snapshots are available at
http://nbody.rc.fas.harvard.edu/public/S2016 .Comment: 13 pages, 8 figures. Minor changes to match MNRAS accepted versio
The switching point between kinetic and thermodynamic control
In organic chemistry, the switching point between the kinetic and thermodynamic control regimes of two competitive, parallel reactions is widely studied. A new definition for this switching point is proposed: the time at which the rates of formation of the competing products are equal. According to this definition, the kinetic control regime is present from the beginning of the reaction, and is valid as long as the rate of formation of the kinetic product is larger than the rate of formation of the thermodynamic product. On the switching point, both rates of formation are equal, so, from this switching point the thermodynamic product has a larger rate of formation, and the thermodynamic control remains until the end of the reaction. A closed form expression is given for the proposed time of the switching point, as a function of the direct and inverse kinetic constants of both competing reactions, as well as the initial concentrations of the starting reagent and the competing products. The concept of competing control regimes is extended also to the case where the reactions start from two competitive reagents which decompose to produce a single product. (C) 2016 Elsevier Ltd. All rights reserved
Noise, transient dynamics, and the generation of realistic interspike interval variation in square-wave burster neurons
First return maps of interspike intervals for biological neurons that
generate repetitive bursts of impulses can display stereotyped structures
(neuronal signatures). Such structures have been linked to the possibility of
multicoding and multifunctionality in neural networks that produce and control
rhythmical motor patterns. In some cases, isolating the neurons from their
synaptic network revealsirregular, complex signatures that have been regarded
as evidence of intrinsic, chaotic behavior.
We show that incorporation of dynamical noise into minimal neuron models of
square-wave bursting (either conductance-based or abstract) produces signatures
akin to those observed in biological examples, without the need for fine-tuning
of parameters or ad hoc constructions for inducing chaotic activity. The form
of the stochastic term is not strongly constrained, and can approximate several
possible sources of noise, e.g. random channel gating or synaptic bombardment.
The cornerstone of this signature generation mechanism is the rich,
transient, but deterministic dynamics inherent in the square-wave
(saddle-node/homoclinic) mode of neuronal bursting. We show that noise causes
the dynamics to populate a complex transient scaffolding or skeleton in state
space, even for models that (without added noise) generate only periodic
activity (whether in bursting or tonic spiking mode).Comment: REVTeX4-1, 18 pages, 9 figure
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