5,354 research outputs found
Off-Campus Library Services in Higher Education in the United Kingdom
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A prospective, double-blind, pilot, randomized, controlled trial of an "embodied" virtual reality intervention for adults with low back pain
Adults with chronic low back pain, disability, moderate-to-severe pain, and high fear of movement and reinjury were recruited into a trial of a novel, automated, digital therapeutics, virtual reality, psychological intervention for pain (DTxP). We conducted a 3-arm, prospective, double-blind, pilot, randomized, controlled trial comparing DTxP with a sham placebo comparator and an open-label standard care. Participants were enrolled for 6 to 8 weeks, after which, the standard care control arm were rerandomized to receive either the DTxP or sham placebo. Forty-two participants completed assessments at baseline, immediately posttreatment (6-8 weeks), 9-week, and 5-month follow-up. We found that participants in the DTxP group reported greater reductions in fear of movement and better global impression of change when compared with sham placebo and standard care post treatment. No other group differences were noted at posttreatment or follow-up. When compared with baseline, participants in the DTxP group reported lower disability at 5-month follow-up, lower pain interference and fear of movement post treatment and follow-up, and lower pain intensity at posttreatment. The sham placebo group also reported lower disability and fear of movement at 5-month follow-up compared with baseline. Standard care did not report any significant changes. There were a number of adverse events, with one participant reporting a serious adverse event in the sham placebo, which was not related to treatment. No substantial changes in medications were noted, and participants in the DTxP group reported positive gaming experiences
Different Transport Pathways of Individual Precursor Proteins in Mitochondria
Transport of mitochondrial precursor proteins into mitochondria of Neurospora crassa was studied in a cellfree reconstituted system. Precursors were synthesized in a reticulocyte lysate programmed with Neurospora mRNA and transported into isolated mitochondria in the absence of protein synthesis. Uptake of the following precursors was investigated: apocytochrome c, ADP/ATP carrier and subunit 9 of the oligomycin-sensitive ATPase.
Addition of high concentrations of unlabelled chemically prepared apocytochrome c (1–10 μM) inhibited the appearance in the mitochondrial of labelled cytochrome c synthesized in vitro because the unlabelled protein dilutes the labelled one and because the translocation system has a limited capacity [apparent V is 1–3 pmol × min−1× (mg mitochondrial protein)−1]. Concentrations of added apocytochrome c exceeding the concentrations of precursor proteins synthesized in vitro by a factor of about 104 did not inhibit the transfer of ADP/ATP carrier or ATPase subunit 9 into mitochondria. Carbonylcyanide m-chlorophenylhydrazone, an uncoupler of oxidative phosphorylation, inhibited transfer in vitro of ADP/ATP carrier and of ATPase subunit 9, but not of cytochrome c.
These findings suggest that cytochrome c and the other two proteins have different import pathways into mitochondria. It can be inferred from the data presented that different 'receptors' on the mitochondrial surface mediate the specific recognition of precursor proteins by mitochondria as a first step in the transport process
Sensitivity of solar off-limb line profiles to electron density stratification and the velocity distribution anisotropy
The effect of the electron density stratification on the intensity profiles
of the H I Ly- line and the O VI and Mg X doublets formed in solar
coronal holes is investigated. We employ an analytical 2-D model of the large
scale coronal magnetic field that provides a good representation of the corona
at the minimum of solar activity. We use the mass-flux conservation equation to
determine the outflow speed of the solar wind at any location in the solar
corona and take into account the integration along the line of sight (LOS). The
main assumption we make is that no anisotropy in the kinetic temperature of the
coronal species is considered. We find that at distances greater than 1 Rsun
from the solar surface the widths of the emitted lines of O VI and Mg X are
sensitive to the details of the adopted electron density stratification.
However, Ly-, which is a pure radiative line, is hardly affected. The
calculated total intensities of Ly- and the O VI doublet depend to a
lesser degree on the density stratification and are comparable to the observed
ones for most of the considered density models. The widths of the observed
profiles of Ly- and Mg X are well reproduced by most of the considered
electron density stratifications, while for the O VI doublet only few
stratifications give satisfying results. The densities deduced from SOHO data
result in O VI profiles whose widths and intensity ratio are relatively close
to the values observed by UVCS although only isotropic velocity distributions
are employed. These density profiles also reproduce the other considered
observables with good accuracy. Thus the need for a strong anisotropy of the
velocity distribution (i.e. a temperature anisotropy) is not so clear cut as
previous investigations of UVCS data suggested. ...Comment: 11 pages; 11 figure
Pearling and Pinching: Propagation of Rayleigh Instabilities
A new category of front propagation problems is proposed in which a spreading
instability evolves through a singular configuration before saturating. We
examine the nature of this front for the viscous Rayleigh instability of a
column of one fluid immersed in another, using the marginal stability criterion
to estimate the front velocity, front width, and the selected wavelength in
terms of the surface tension and viscosity contrast. Experiments are suggested
on systems that may display this phenomenon, including droplets elongated in
extensional flows, capillary bridges, liquid crystal tethers, and viscoelastic
fluids. The related problem of propagation in Rayleigh-like systems that do not
fission is also considered.Comment: Revtex, 7 pages, 4 ps figs, PR
Kondo engineering : from single Kondo impurity to the Kondo lattice
In the first step, experiments on a single cerium or ytterbium Kondo impurity
reveal the importance of the Kondo temperature by comparison to other type of
couplings like the hyperfine interaction, the crystal field and the intersite
coupling. The extension to a lattice is discussed. Emphasis is given on the
fact that the occupation number of the trivalent configuration may be the
implicit key variable even for the Kondo lattice. Three phase
diagrams are discussed: CeRuSi, CeRhIn and SmS
Non linear sigma models and quantum spin systems
Microscopic models of quantum antiferromagnets are investigated on the basis
of a mapping onto effective low energy hamiltonians. Lattice effects are
carefully taken into account and their role is discussed. We show that the
presence of an external staggered magnetic field modifies in a non trivial way
the usual mapping onto the non linear sigma model, leading to the appearance of
new terms, neglected in previous works. Our analysis is compared with Lanczos
diagonalizations of S=1 Heisenberg chains in a staggered field, confirming the
validity of the single mode approximation for the evaluation of the dynamical
structure factor. The results are relevant for the interpretation of
experiments in quasi-one dimensional compounds. Microscopic realizations of
SU(4) spin chains are also discussed in the framework of spin-orbital lattice
systems. The low energy physics is shown to be described by sigma models with
topological angle in one dimension. This mapping strongly suggests
that the one dimensional CP model (with ) undergoes a second
order phase transition as a function of the coupling.Comment: 11 pages, 5 figures, Corrected typos. To appear in Phys. Rev.
A prospective, double-blind, pilot, randomized, controlled trial of an "embodied" virtual reality intervention for adults with low back pain
Adults with chronic low back pain, disability, moderate-to-severe pain, and high fear of movement and reinjury were recruited into a trial of a novel, automated, digital therapeutics, virtual reality, psychological intervention for pain (DTxP). We conducted a 3-arm, prospective, double-blind, pilot, randomized, controlled trial comparing DTxP with a sham placebo comparator and an open-label standard care. Participants were enrolled for 6 to 8 weeks, after which, the standard care control arm were rerandomized to receive either the DTxP or sham placebo. Forty-two participants completed assessments at baseline, immediately posttreatment (6-8 weeks), 9-week, and 5-month follow-up. We found that participants in the DTxP group reported greater reductions in fear of movement and better global impression of change when compared with sham placebo and standard care post treatment. No other group differences were noted at posttreatment or follow-up. When compared with baseline, participants in the DTxP group reported lower disability at 5-month follow-up, lower pain interference and fear of movement post treatment and follow-up, and lower pain intensity at posttreatment. The sham placebo group also reported lower disability and fear of movement at 5-month follow-up compared with baseline. Standard care did not report any significant changes. There were a number of adverse events, with one participant reporting a serious adverse event in the sham placebo, which was not related to treatment. No substantial changes in medications were noted, and participants in the DTxP group reported positive gaming experiences
Local fluctuations in quantum critical metals
We show that spatially local, yet low-energy, fluctuations can play an
essential role in the physics of strongly correlated electron systems tuned to
a quantum critical point. A detailed microscopic analysis of the Kondo lattice
model is carried out within an extended dynamical mean-field approach. The
correlation functions for the lattice model are calculated through a
self-consistent Bose-Fermi Kondo problem, in which a local moment is coupled
both to a fermionic bath and to a bosonic bath (a fluctuating magnetic field).
A renormalization-group treatment of this impurity problem--perturbative in
, where is an exponent characterizing the spectrum
of the bosonic bath--shows that competition between the two couplings can drive
the local-moment fluctuations critical. As a result, two distinct types of
quantum critical point emerge in the Kondo lattice, one being of the usual
spin-density-wave type, the other ``locally critical.'' Near the locally
critical point, the dynamical spin susceptibility exhibits scaling
with a fractional exponent. While the spin-density-wave critical point is
Gaussian, the locally critical point is an interacting fixed point at which
long-wavelength and spatially local critical modes coexist. A Ginzburg-Landau
description for the locally critical point is discussed. It is argued that
these results are robust, that local criticality provides a natural description
of the quantum critical behavior seen in a number of heavy-fermion metals, and
that this picture may also be relevant to other strongly correlated metals.Comment: 20 pages, 12 figures; typos in figure 3 and in the main text
corrected, version as publishe
Smoking among Young Rural to Urban Migrant Women in China: A Cross-Sectional Survey
Rural-to-urban migrant women may be vulnerable to smoking initiation as they are newly exposed to risk factors in the urban environment. We sought to identify correlates of smoking among rural-to-urban migrant women in China.A cross-sectional survey of rural-to-urban migrant women working in restaurants and hotels (RHW) and those working as commercial sex workers (CSW) was conducted in ten provincial capital cities in China. Multiple logistic regression was conducted to identify correlates of smoking. We enrolled 2229 rural-to-urban migrant women (1697 RHWs aged 18–24 years and 532 CSWs aged 18–30 years). Of these, 18.4% RHWs and 58.3% CSWs reported ever tried smoking and 3.2% RHWs and 41.9% CSWs reported current smoking. Participants who first tried smoking after moving to the city were more likely to be current smokers compared to participants who first tried smoking before moving to the city (25.3% vs. 13.8% among RHWs, p = 0.02; 83.6% vs. 58.6% among CSWs, p = <0.01). Adjusting for other factors, “tried female cigarette brands” had the strongest association with current smoking (OR 5.69, 95%CI 3.44 to 9.41) among participants who had ever tried smoking.Exposure to female cigarette brands may increase the susceptibility to smoking among rural-to-urban migrant women. Smoke-free policies and increased taxes may be effective in preventing rural-to-urban migrant women from smoking initiation
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