8,912 research outputs found
Spectrum of topics for world congresses and other activities of the International Society for Physical and Rehabilitation Medicine (ISPRM) : a first proposal
Background: One of the objectives of the International Society for Physical and Rehabilitation Medicine is to improve the continuity of World Congresses. This requires the development of an abstract topic list for use in congress announcements and abstract submissions.
Methods: An abstract topic list was developed on the basis of the definitions of human functioning and rehabilitation research, which define 5 main areas of research (biosciences in rehabilitation, biomedical rehabilitation sciences and engineering, clinical Physical and Rehabilitation Medicine (PRM) sciences, integrative rehabilitation sciences, and human functioning sciences). For the abstract topic list, these research areas were grouped according to the proposals of congress streams. In a second step, the first version of the list was systematically compared with the topics of the 2003 ISPRM World Congress.
Results: The resulting comprehensive abstract topic list contains 5 chapters according to the definition of human functioning and rehabilitation research. Due to the high significance of clinical research, clinical PRM sciences were placed at the top of the list, comprising all relevant health conditions treated in PRM services. For congress announcements a short topic list was derived.
Discussion: The ISPRM topic list is sustainable and covers a full range of topics. It may be useful for congresses and elsewhere in structuring research in PRM
Oral Administration of Levo-Tetrahydropalmatine Attenuates Reinstatement of Extinguished Cocaine Seeking by Cocaine, Stress or Drug-Associated Cues in Rats
Cocaine addiction is characterized by a persistently heightened susceptibility to drug relapse. For this reason, the identification of medications that prevent drug relapse is a critical goal of drug abuse research. Drug re-exposure, the onset of stressful life events, and exposure to cues previously associated with drug use have been identified as determinants of relapse in humans and have been found to reinstate extinguished cocaine seeking in rats. This study examined the effects of acute oral (gavage) administration of levo-tetrahydropalmatine (l-THP), a tetrahydroprotoberberine isoquinoline with a pharmacological profile that includes antagonism of D1, D2 and D3 dopamine receptors, on the reinstatement of extinguished cocaine seeking by a cocaine challenge (10 mg/kg, ip), a stressor (uncontrollable electric footshock [EFS]) or response-contingent exposure to a stimulus (tone and light complex) previously associated with drug delivery in male Sprague–Dawley rats. Extinguished drug seeking was reinstated by ip cocaine, EFS, or response-contingent presentation of drug-associated cues in vehicle-pretreated rats following extinction of iv cocaine self-adminisration. Oral administration of either 3.0 or 10.0 mg/kg l-THP 1 h prior to reinstatement testing significantly attenuated reinstatement by each of the stimuli. Food-reinforced responding and baseline post-extinction responding were significantly attenuated at the 10.0, but not the 3.0 mg/kg, l-THP dose, indicating that the effects of 3 mg/kg l-THP on reinstatement were likely independent of non-specific motor impairment. These findings further suggest that l-THP may have utility for the treatment of cocaine addiction
Influence of intrinsic decoherence on nonclassical properties of the output of a Bose-Einstein condensate
We investigate nonclassical properties of the output of a Bose-Einstein
condensate in Milburn's model of intrinsic decoherence. It is shown that the
squeezing property of the atom laser is suppressed due to decoherence.
Nevertheless, if some very special conditions were satisfied, the squeezing
properties of atom laser could be robust against the decoherence.Comment: 17 pages, 5 figures, Late
The Distribution and Excitation of CH₃CN in a Solar Nebula Analog
Cometary studies suggest that the organic composition of the early Solar Nebula was rich in complex nitrile species such CH3CN. Recent ALMA detections in protoplanetary disks suggest that these species may be common during planet and comet formation, but connecting gas-phase measurements to cometary abundances first requires constraints on formation chemistry and distributions of these species. We present here the detection of seven spatially resolved transitions of CH3CN in the protoplanetary disk around the T-Tauri star TW Hya. Using a rotational diagram analysis, we find a disk-averaged column density of cm−2 and a rotational temperature of K. A radially resolved rotational diagram shows the rotational temperature to be constant across the disk, suggesting that the CH3CN emission originates from a layer at z/r ~ 0.3. Through comparison of the observations with predictions from a disk chemistry model, we find that grain-surface reactions likely dominate CH3CN formation and that in situ disk chemistry is sufficient to explain the observed CH3CN column density profile without invoking inheritance from the protostellar phase. However, the same model fails to reproduce a solar system cometary abundance of CH3CN relative to H2O in the midplane, suggesting that either vigorous vertical mixing or some degree of inheritance from interstellar ices occurred in the Solar Nebula
Widespread recombination, reassortment, and transmission of unbalanced compound viral genotypes in natural arenavirus infections.
Arenaviruses are one of the largest families of human hemorrhagic fever viruses and are known to infect both mammals and snakes. Arenaviruses package a large (L) and small (S) genome segment in their virions. For segmented RNA viruses like these, novel genotypes can be generated through mutation, recombination, and reassortment. Although it is believed that an ancient recombination event led to the emergence of a new lineage of mammalian arenaviruses, neither recombination nor reassortment has been definitively documented in natural arenavirus infections. Here, we used metagenomic sequencing to survey the viral diversity present in captive arenavirus-infected snakes. From 48 infected animals, we determined the complete or near complete sequence of 210 genome segments that grouped into 23 L and 11 S genotypes. The majority of snakes were multiply infected, with up to 4 distinct S and 11 distinct L segment genotypes in individual animals. This S/L imbalance was typical: in all cases intrahost L segment genotypes outnumbered S genotypes, and a particular S segment genotype dominated in individual animals and at a population level. We corroborated sequencing results by qRT-PCR and virus isolation, and isolates replicated as ensembles in culture. Numerous instances of recombination and reassortment were detected, including recombinant segments with unusual organizations featuring 2 intergenic regions and superfluous content, which were capable of stable replication and transmission despite their atypical structures. Overall, this represents intrahost diversity of an extent and form that goes well beyond what has been observed for arenaviruses or for viruses in general. This diversity can be plausibly attributed to the captive intermingling of sub-clinically infected wild-caught snakes. Thus, beyond providing a unique opportunity to study arenavirus evolution and adaptation, these findings allow the investigation of unintended anthropogenic impacts on viral ecology, diversity, and disease potential
Ideal magnetohydrodynamic simulations of unmagnetized dense plasma jet injection into a hot strongly magnetized plasma
We present results from three-dimensional ideal magnetohydrodynamic
simulations of unmagnetized dense plasma jet injection into a uniform hot
strongly magnetized plasma, with the aim of providing insight into core fueling
of a tokamak with parameters relevant for ITER and NSTX (National Spherical
Torus Experiment). Unmagnetized dense plasma jet injection is similar to
compact toroid injection but with much higher plasma density and total mass,
and consequently lower required injection velocity. Mass deposition of the jet
into the background appears to be facilitated via magnetic reconnection along
the jet's trailing edge. The penetration depth of the plasma jet into the
background plasma is mostly dependent on the jet's initial kinetic energy, and
a key requirement for spatially localized mass deposition is for the jet's
slowing-down time to be less than the time for the perturbed background
magnetic flux to relax due to magnetic reconnection. This work suggests that
more accurate treatment of reconnection is needed to fully model this problem.
Parameters for unmagnetized dense plasma jet injection are identified for
localized core deposition as well as edge localized mode (ELM) pacing
applications in ITER and NSTX-relevant regimes.Comment: 16 pages, 8 figures and 2 tables; accepted by Nuclear Fusion (May 11,
2011
UV+IR Star Formation Rates: Hickson Compact Groups with Swift and Spitzer
We present Swift UVOT (1600-3000A) 3-band photometry for 41 galaxies in 11
nearby (<4500km/s) Hickson Compact Groups (HCGs) of galaxies. We use the
uvw2-band (2000A) to estimate the dust-unobscured component, SFR_UV, of the
total star-formation rate, SFR_T. We use Spitzer MIPS 24-micron photometry to
estimate SFR_IR, the dust-obscured component of SFR_T. We obtain
SFR_T=SFR_UV+SFR_IR. Using 2MASS K_s band based stellar mass, M*, estimates, we
calculate specific SFRs, SSFR=SFR_T/M*. SSFR values show a clear and
significant bimodality, with a gap between low (<~3.2x10^-11 / yr) and high
SSFR (>~1.2x10^-10 / yr) systems. All galaxies with MIR activity index a_IRAC
0) are in the high- (low-) SSFR locus, as expected if high levels of
star-formation power MIR emission from polycyclic aromatic hydrocarbon
molecules and a hot dust continuum. All elliptical/S0 galaxies are in the
low-SSFR locus, while 22 out of 24 spirals/irregulars are in the high-SSFR
locus, with two borderline cases. We divide our sample into three subsamples
(I, II and III) according to decreasing HI-richness of the parent galaxy group
to which a galaxy belongs. Consistent with the SSFR and a_IRAC bimodality, 12
out of 15 type-I (11 out of 12 type-III) galaxies are in the high- (low-) SSFR
locus, while type II galaxies span almost the full range of SSFR values. Unlike
HCG galaxies, galaxies in a comparison quiescent SINGS sub-sample are
continuously distributed both in SSFR and a_IRAC. Any uncertainties can only
further enhance the SSFR bimodality. These results suggest that an environment
characterized by high galaxy number-densities and low galaxy
velocity-dispersions, such as the one found in compact groups, plays a key role
in accelerating galaxy evolution by enhancing star-formation processes in
galaxies and favoring a fast transition to quiescence.(abridged)Comment: Accepted by ApJ. [8 Tables, 16 Figures. Color figures have reduced
size for ArXiv - emulateapj v. 2/16/10
Structure and thermal behavior of nanocrystalline boehmite
First, the structural features of nanocrystalline boehmite synthesized by hydrolysis of aluminum sec-butoxide according to the Yoldas method are reported. The nanosized boehmite consists of rectangular platelets averaging 8 by 9 nm and 2–3 nm in thickness which contain a large excess of water. Dehydration by heating under vacuum induced an increase in the specific surface area, down to a minimum water content ( 0.2 H2O per Al2O3); values up to 470 m2/g can be reached. However this enlargement of specific surface area only results from water loss, the surface area remaining constant. The particle morphology, the excess of water,
as well as the specific surface area, depend on the amount of acid used for the peptization during the synthesis. Second, a comprehensive investigation of the dehydration kinetics is presented. The simulations of the non-isothermal experiments at constant heating rates show that thermally stimulated transformation of nanocrystalline boehmite into alumina can be accurately modeled by a 4-reaction mechanism involving: (I) the loss of physisorbed water, (II) the loss of chemisorbed water, (III) the conversion of boehmite into transition alumina, (IV) the dehydration of transition alumina (loss of residual hydroxyl groups). The activation energy of each step is found to be very similar for experiments done in various conditions (heating rate, atmosphere, kind of sample,…)
Non-spherical core collapse supernovae III. Evolution towards homology and dependence on the numerical resolution
(abridged) We study the hydrodynamic evolution of a non-spherical
core-collapse supernova in two spatial dimensions. We find that our model
displays a strong tendency to expand toward the pole. We demonstrate that this
expansion is a physical property of the low-mode, SASI instability. The SASI
leaves behind a large lateral velocity gradient in the post shock layer which
affects the evolution for minutes and hours later. This results in a prolate
deformation of the ejecta and a fast advection of Ni-rich material from
moderate latitudes to the polar regions. This effect might actually be
responsible for the global asymmetry of the nickel lines in SN 1987A. The
simulations demonstrate that significant radial and lateral motions in the
post-shock region, produced by convective overturn and the SASI during the
early explosion phase, contribute to the evolution for minutes and hours after
shock revival. They lead to both later clump formation, and a significant
prolate deformation of the ejecta which are observed even as late as one week
after the explosion. As pointed out recently by Kjaer et al., such an ejecta
morphology is in good agreement with the observational data of SN 1987A.
Systematic future studies are needed to investigate how the SASI-induced
late-time lateral expansion depends on the dominant mode of the SASI, and to
which extent it is affected by the dimensionality of the simulations. The
impact on and importance of the SASI for the distribution of iron group nuclei
and the morphology of the young SNR argues for future three-dimensional
explosion and post-explosion studies on singularity-free grids that cover the
entire sphere. Given the results of our 2D resolution study, present 3D
simulations must be regarded as underresolved, and their conclusions must be
verified by a proper numerical convergence analysis in three dimensions.Comment: 16 pages, 20 figures, accepted for publication in Astronomy &
Astrophysic
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