958 research outputs found
Vulnerability and Post-Stroke Experiences of Working-Age Survivors During Recovery
Survivors who experience stroke of mild to moderate severity are
typically discharged home quickly, with only minimal referral for rehabilitation
follow-up or support to meet specific needs in recovery. Particular vulnerabilities of
younger, higher functioning stroke survivors have received some recognition in
international literature in recent years. This article reports on findings of a small
Australian qualitative study focusing on recovery and return to work experiences of
young higher functioning female stroke survivors, in particular exploring experiences of
post-stroke vulnerability from participants’ own perspectives. Our research adds depth
and nuance to this developing area of interest and research. Our findings include
survivors’ reflections on the consequences of delayed diagnosis, the impacts of
empowering and disempowering interactions with health care professionals, a general lack
of access to psychosocial rehabilitation, and frustrations of financial hardship.
Implications for health professionals, service systems, and income support provision are
discussed, along with directions for future research
Metropolis simulations of Met-Enkephalin with solvent-accessible area parameterizations
We investigate the solvent-accessible area method by means of Metropolis
simulations of the brain peptide Met-Enkephalin at 300. For the energy
function ECEPP/2 nine atomic solvation parameter (ASP) sets are studied. The
simulations are compared with one another, with simulations with a distance
dependent electrostatic permittivity , and with vacuum
simulations (). Parallel tempering and the biased Metropolis
techniques RM are employed and their performance is evaluated. The measured
observables include energy and dihedral probability densities (pds), integrated
autocorrelation times, and acceptance rates. Two of the ASP sets turn out to be
unsuitable for these simulations. For all other systems selected configurations
are minimized in search of the global energy minima, which are found for the
vacuum and the system, but for none of the ASP models. Other
observables show a remarkable dependence on the ASPs. In particular, we find
three ASP sets for which the autocorrelations at 300K are considerably
smaller than for vacuum simulations.Comment: 10 pages and 8 figure
Analysis of acoustic emission during the melting of embedded indium particles in an aluminum matrix: a study of plastic strain accommodation during phase transformation
Acoustic emission is used here to study melting and solidification of
embedded indium particles in the size range of 0.2 to 3 um in diameter and to
show that dislocation generation occurs in the aluminum matrix to accommodate a
2.5% volume change. The volume averaged acoustic energy produced by indium
particle melting is similar to that reported for bainite formation upon
continuous cooling. A mechanism of prismatic loop generation is proposed to
accommodate the volume change and an upper limit to the geometrically necessary
increase in dislocation density is calculated as 4.1 x 10^9 cm^-2 for the
Al-17In alloy. Thermomechanical processing is also used to change the size and
distribution of the indium particles within the aluminum matrix. Dislocation
generation with accompanied acoustic emission occurs when the melting indium
particles are associated with grain boundaries or upon solidification where the
solid-liquid interfaces act as free surfaces to facilitate dislocation
generation. Acoustic emission is not observed for indium particles that require
super heating and exhibit elevated melting temperatures. The acoustic emission
work corroborates previously proposed relaxation mechanisms from prior internal
friction studies and that the superheat observed for melting of these
micron-sized particles is a result of matrix constraint.Comment: Presented at "Atomistic Effects in Migrating Interphase Interfaces -
Recent Progress and Future Study" TMS 201
Resonant nonlinear magneto-optical effects in atoms
In this article, we review the history, current status, physical mechanisms,
experimental methods, and applications of nonlinear magneto-optical effects in
atomic vapors. We begin by describing the pioneering work of Macaluso and
Corbino over a century ago on linear magneto-optical effects (in which the
properties of the medium do not depend on the light power) in the vicinity of
atomic resonances, and contrast these effects with various nonlinear
magneto-optical phenomena that have been studied both theoretically and
experimentally since the late 1960s. In recent years, the field of nonlinear
magneto-optics has experienced a revival of interest that has led to a number
of developments, including the observation of ultra-narrow (1-Hz)
magneto-optical resonances, applications in sensitive magnetometry, nonlinear
magneto-optical tomography, and the possibility of a search for parity- and
time-reversal-invariance violation in atoms.Comment: 51 pages, 23 figures, to appear in Rev. Mod. Phys. in Oct. 2002,
Figure added, typos corrected, text edited for clarit
Alcohol consumption and sport: a cross-sectional study of alcohol management practices associated with at-risk alcohol consumption at community football clubs
BackgroundExcessive alcohol consumption is responsible for considerable harm from chronic disease and injury. Within most developed countries, members of sporting clubs participate in at-risk alcohol consumption at levels above that of communities generally. There has been limited research investigating the predictors of at-risk alcohol consumption in sporting settings, particularly at the non-elite level. The purpose of this study was to examine the association between the alcohol management practices and characteristics of community football clubs and at-risk alcohol consumption by club members.MethodsA cross sectional survey of community football club management representatives and members was conducted. Logistic regression analysis (adjusting for clustering by club) was used to determine the association between the alcohol management practices (including alcohol management policy, alcohol-related sponsorship, availability of low- and non-alcoholic drinks, and alcohol-related promotions, awards and prizes) and characteristics (football code, size and location) of sporting clubs and at-risk alcohol consumption by club members.ResultsMembers of clubs that served alcohol to intoxicated people [OR: 2.23 (95% CI: 1.26-3.93)], conducted ‘happy hour’ promotions [OR: 2.84 (95% CI: 1.84-4.38)] or provided alcohol-only awards and prizes [OR: 1.80 (95% CI: 1.16-2.80)] were at significantly greater odds of consuming alcohol at risky levels than members of clubs that did not have such alcohol management practices. At-risk alcohol consumption was also more likely among members of clubs with less than 150 players compared with larger clubs [OR:1.45 (95% CI: 1.02-2.05)] and amongst members of particular football codes.ConclusionsThe findings of this study suggest a need and opportunity for the implementation of alcohol harm reduction strategies targeting specific alcohol management practices at community football clubs.<br /
Effect of grain and secondary phase morphologies in the mechanical and damping behavior of Al7075 alloys
The present study evaluates the role of the microstructure in the static and dynamic mechanical behavior of as-cast Al7075 alloy promoted by ultrasonic treatment (US) during solidification. The characterization of samples revealed that US treatment promoted grain and intermetallics refinement, changed the shape of the intermetallic phases (equilibrium phases of soluble M and/or T (Al, Cu, Mg, Zn) and their insoluble Al-Cu-Fe compounds) and lead to their uniform distribution along the grain boundaries. Consequently, the mechanical properties and damping capacity above critical strain values were enhanced by comparison with values obtained for castings produced without US vibration. This results suggest that the grain and secondary phases refinement by US can be a promising solution to process materials to obtain high damping and high strength characteristics.This research was supported by FEDER/COMPETE funds and by national funds through FCT - Portuguese Foundation for Science and Technology and was developed on the aim of the research Post-Doctoral grant SFRH/BPD/76680/2011. Also, this work has been supported by the FCT in the scope of the project: UID/EEA/04436/2013.info:eu-repo/semantics/publishedVersio
Phosphate Monoester Hydrolysis in Cyclohexane
The hydrolysis of simple phosphate monoesters is among the most difficult reactions that are subject to catalysis by enzymes, and it has been suggested that extraction of the substrates from solvent water may contribute to the catalytic effects of phosphohydrolases. Here, we show that the tetrabutylammonium salt of neopentyl phosphate enters wet cyclohexane at concentrations sufficient to allow determination of its rate of hydrolysis. The second-order rate constant for hydrolysis of the phosphomonoester dianion is enhanced approximately 2 x 10(12)-fold by transfer from water to cyclohexane. That rate enhancement arises from an increase in the entropy of activation
The hydrolysis of phosphate diesters in cyclohexane and acetone
The hydrolysis of phosphate diesters is one of the most difficult reactions known. Here we show that in acetone or cyclohexane, at 25 °C, phosphodiesters undergo hydrolysis 5 × 105 and 2 × 109-fold more rapidly than in water, respectively, and that this rate enhancement is achieved by lowering the enthalpy of activation
Trophic Conditions and Planktonic Processes of Semi-arid Floodplain Lakes Inundated with Environmental Flows
Shallow floodplain lakes are critical components of semi-arid floodplain wetland systems. Delivery of environmental flows that aim to sustain ecological processes of semi-arid floodplain wetlands has enhanced inundation of shallow lakes in inland Australia. To maximise environmental flow outcomes to support floodplain productivity and ecosystem functions, environmental managers would benefit from knowing whether semi-arid floodplain lakes function as a sink or source of atmospheric carbon. We investigated abiotic conditions, and rates of planktonic respiration and primary productivity of phytoplankton during summer under environmental flow conditions in three floodplain lakes of the lower Murrumbidgee River, Australia. All lakes showed mesoeutrophic to hypereutrophic characteristics and significant within- and between-lake variability in abiotic conditions, planktonic processes, and associated carbon balance. Nevertheless, the mean net primary productivity of phytoplankton in the lakes (364-1,674 mg C m-2 day-1) were up to about three times greater than in other semi-arid floodplain wetlands of southeast Australia. Therefore, shallow floodplain lakes in semi-arid regions have great potential to function as a sink of atmospheric carbon through planktonic metabolism during summer. A spatial hierarchical framework for lake functional response to inundation is proposed to support decision-making and to maximise the benefits of environmental flow regimes for floodplain lakes
Molecular dynamics simulation studies of the interactions between ionic liquids and amino acids in aqueous solution
Although the understanding of the influence of ionic liquids (ILs) on the solubility behavior of biomolecules in aqueous solutions is relevant for the design and optimization of novel biotechnological processes, the underlying molecular-level mechanisms are not yet consensual or clearly elucidated. In order to contribute to the understanding of the molecular interactions established between amino acids and ILs in aqueous media, classical molecular dynamics (MD) simulations were performed for aqueous solutions of five amino acids with different structural characteristics (glycine, alanine, valine, isoleucine, and glutamic acid) in the presence of 1-butyl-3-methylimidazolium bis(trifluoromethyl)sulfonyl imide. The results from MD simulations enable to relate the properties of the amino acids, namely their hydrophobicity, to the type and strength of their interactions with ILs in aqueous solutions and provide an explanation for the direction and magnitude of the solubility phenomena observed in [IL + amino acid + water] systems by a mechanism governed by a balance between competitive interactions of the IL cation, IL anion, and water with the amino acids
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