774 research outputs found
The influence of psychiatric morbidity on return to paid work after stroke in younger adults: The auckland regional community stroke (ARCOS) study, 2002 to 2003
BACKGROUND AND PURPOSE-: Few data exist on the determinants of return to paid work after stroke, yet participation in employment is vital to a person's mental well-being and role in society. This study aimed to determine the frequency and determinants of return to work, in particular the effect of early psychiatric morbidity, in a population-based study of stroke survivors. METHODS-: The third Auckland Regional Community Stroke (ARCOS) study was a prospective, population-based, stroke incidence study undertaken in Auckland, New Zealand during 2002 to 2003. After a baseline assessment early after stroke, data were collected on all survivors at 1 and 6 months follow-up. Multiple variable logistic regression was used to determine predictors of return to paid work. Data are reported with odds ratios (OR) and 95% confidence intervals (CI). RESULTS-: Among 1423 patients registered with first-ever strokes, there were 210 previously in paid employment who survived to 6 months, of whom 155 (74%) completed the GHQ-28 and 112 (53%) had returned to paid work. Among those cognitively competent, psychiatric morbidity at 28 days was a strong independent predictor of not returning to work (Odds Ratio 0.39; 95% CI 0.22 to 0.80). Non-New Zealand European ethnicity (OR 0.40; 95% CI 0.17 to 0.91), prior part-time, as opposed to full-time, employment 0.36 (0.15 to 0.89), and not being functionally independent soon after the stroke 0.28 (0.13 to 0.59) were the other independent age- and gender-adjusted predictors of not successfully returning to paid work. CONCLUSIONS-: About half of previously employed people return to paid employment after stroke, with psychiatric morbidity and physical disability being independent, yet potentially treatable, determinants of this outcome. Appropriate management of both emotional and physical sequelae would appear necessary for optimizing recovery and return to work in younger adults after stroke
Influence of typical environments on quantum processes
We present the results of studying the influence of different environmental
states on the coherence of quantum processes. We choose to discuss a simple
model which describe two electronic reservoirs connected through tunneling via
a resonant state. The model could, e.g., serve as an idealization of inelastic
resonant tunneling through a double barrier structure. We develop Schwinger's
closed time path formulation of non-equilibrium quantum statistical mechanics,
and show that the influence of the environment on a coherent quantum process
can be described by the value of a generating functional at a specific force
value, thereby allowing for a unified discussion of destruction of phase
coherence by various environmental states: thermal state, classical noise, time
dependent classical field, and a coherent state. The model allows an extensive
discussion of the influence of dissipation on the coherent quantum process, and
expressions for the transmission coefficient are obtained in the possible
limits.Comment: 46 pages, 11 post script figures. Accepted for publication in
Physical Review
Fish Indicators of Ecosystem Health: Upper Mississippi River System
Following the UMRRAnalysis Team’s recommendations, our reportdescribesthe development of backwater assemblage and migratory fish indicators and their responsessince the beginning of the UMRR LTRMdata collection. The data used for these indicators are summarized aspool-wide totalsfrom the UMRR LTRMelement. In addition, we also present a practical solution to the problem of determining reference condition in the absence of true reference sites in navigable rivers by using an internal quantitative baseline condition determined by a long-term
UMRR Fish Indicators data trend at the reach-scale.Lastly, we outline our recommendation for the development of indicator that evaluates the young-of-the-year fish assemblage.United States Geological Survey (USGS)U.S. Army Corps of Engineersunpublishednot peer reviewedOpe
Charge and spin configurations in the coupled quantum dots with Coulomb correlations induced by tunneling current
We investigated the peculiarities of non-equilibrium charge states and spin
configurations in the system of two strongly coupled quantum dots (QDs) weakly
connected to the electrodes in the presence of Coulomb correlations. We
analyzed the modification of non-equilibrium charge states and different spin
configurations of the system in a wide range of applied bias voltage and
revealed well pronounced ranges of system parameters where negative tunneling
conductivity appears due to the Coulomb correlations.Comment: 10 pages, 6 figure
Sociocultural considerations in aging men's health: implications and recommendations for the clinician
http://dx.doi.org/10.1016/j.jomh.2009.07.00
Probing the innermost regions of AGN jets and their magnetic fields with radioastron. I. Imaging BL LACERTAE at 21 μm as resolution
We present the first polarimetric space very long baseline interferometry (VLBI) imaging observations at 22 GHz. BL Lacertae was observed in 2013 November 10 with the RadioAstron space VLBI mission, including a ground array of 15 radio telescopes. The instrumental polarization of the space radio telescope is found to be less than 9%, demonstrating the polarimetric imaging capabilities of RadioAstron at 22 GHz. Ground-space fringes were obtained up to a projected baseline distance of 7.9 Earth diameters in length, allowing us to image the jet in BL Lacertae with a maximum angular resolution of 21 μas, the highest achieved to date. We find evidence for emission upstream of the radio core, which may correspond to a recollimation shock at about 40 μas from the jet apex, in a pattern that includes other recollimation shocks at approximately 100 and 250 μas from the jet apex. Polarized emission is detected in two components within the innermost 0.5 mas from the core, as well as in some knots 3 mas downstream. Faraday rotation analysis, obtained from combining RadioAstron 22 GHz and ground-based 15 and 43 GHz images, shows a gradient in rotation measure and Faraday-corrected polarization vector as a function of position angle with respect to the core, suggesting that the jet in BL Lacertae is threaded by a helical magnetic field. The intrinsic de-boosted brightness temperature in the unresolved core exceeds K, suggesting, at the very least, departure from equipartition of energy between the magnetic field and radiating particles.This research has been supported by the Spanish Ministry of Economy and Competitiveness grant AYA2013-40825-P, by the Russian Foundation for Basic Research (projects 13-02-12103, 14-02-31789, and 15-02-00949), and St. Petersburg University research grant 6.38.335.2015. The research at Boston University (BU) was funded in part by NASA Fermi Guest Investigator grant NNX14AQ58G. Y.M. acknowledges support from the ERC Synergy Grant >BlackHoleCam-Imaging the Event Horizon of Black Holes> (Grant 610058). Part of this work was supported by the COST Action MP1104 >Polarization as a tool to study the Solar System and beyond.> The RadioAstron project is led by the Astro Space Center of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the Russian Federal Space Agency, in collaboration with partner organizations in Russia and other countries.Peer Reviewe
Kondo effect in systems with dynamical symmetries
This paper is devoted to a systematic exposure of the Kondo physics in
quantum dots for which the low energy spin excitations consist of a few
different spin multiplets . Under certain conditions (to be
explained below) some of the lowest energy levels are nearly
degenerate. The dot in its ground state cannot then be regarded as a simple
quantum top in the sense that beside its spin operator other dot (vector)
operators are needed (in order to fully determine its quantum
states), which have non-zero matrix elements between states of different spin
multiplets . These "Runge-Lenz"
operators do not appear in the isolated dot-Hamiltonian (so in some sense they
are "hidden"). Yet, they are exposed when tunneling between dot and leads is
switched on. The effective spin Hamiltonian which couples the metallic electron
spin with the operators of the dot then contains new exchange terms,
beside the ubiquitous ones . The operators and generate a
dynamical group (usually SO(n)). Remarkably, the value of can be controlled
by gate voltages, indicating that abstract concepts such as dynamical symmetry
groups are experimentally realizable. Moreover, when an external magnetic field
is applied then, under favorable circumstances, the exchange interaction
involves solely the Runge-Lenz operators and the corresponding
dynamical symmetry group is SU(n). For example, the celebrated group SU(3) is
realized in triple quantum dot with four electrons.Comment: 24 two-column page
Nonequilibrium Transport through a Kondo Dot in a Magnetic Field: Perturbation Theory
Using nonequilibrium perturbation theory, we investigate the nonlinear
transport through a quantum dot in the Kondo regime in the presence of a
magnetic field. We calculate the leading logarithmic corrections to the local
magnetization and the differential conductance, which are characteristic of the
Kondo effect out of equilibrium. By solving a quantum Boltzmann equation, we
determine the nonequilibrium magnetization on the dot and show that the
application of both a finite bias voltage and a magnetic field induces a novel
structure of logarithmic corrections not present in equilibrium. These
corrections lead to more pronounced features in the conductance, and their form
calls for a modification of the perturbative renormalization group.Comment: 16 pages, 7 figure
Strangeness Enhancement in and Interactions at SPS Energies
The systematics of strangeness enhancement is calculated using the HIJING and
VENUS models and compared to recent data on , and
collisions at CERN/SPS energies (). The HIJING model is used to
perform a {\em linear} extrapolation from to . VENUS is used to
estimate the effects of final state cascading and possible non-conventional
production mechanisms. This comparison shows that the large enhancement of
strangeness observed in collisions, interpreted previously as possible
evidence for quark-gluon plasma formation, has its origins in non-equilibrium
dynamics of few nucleon systems. % Strangeness enhancement %is therefore traced
back to the change in the production dynamics %from to minimum bias
and central collisions. A factor of two enhancement of at
mid-rapidity is indicated by recent data, where on the average {\em one}
projectile nucleon interacts with only {\em two} target nucleons. There appears
to be another factor of two enhancement in the light ion reaction relative
to , when on the average only two projectile nucleons interact with two
target ones.Comment: 29 pages, 8 figures in uuencoded postscript fil
Neutron Knockout Reactions at Medium Energies
Supported by the National Science Foundation and Indiana Universit
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