13,277 research outputs found
A qualitative study of primary care professionals’ views of case finding for depression in patients with diabetes or coronary heart disease in the UK
<p>Background
Routinely conducting case finding (also commonly referred to as screening) in patients with chronic illness for depression in primary care appears to have little impact. We explored the views and experiences of primary care nurses, doctors and managers to understand how the implementation of case finding/screening might impact on its effectiveness.</p>
<p>Methods
Two complementary qualitative focus group studies of primary care professionals including nurses, doctors and managers, in five primary care practices and five Community Health Partnerships, were conducted in Scotland.</p>
<p>Results
We identified several features of the way case finding/screening was implemented that may lead to systematic under-detection of depression. These included obstacles to incorporating case finding/screening into a clinical review consultation; a perception of replacing individualised care with mechanistic assessment, and a disconnection for nurses between management of physical and mental health. Far from being a standardised process that encouraged detection of depression, participants described case finding/screening as being conducted in a way which biased it towards negative responses, and for nurses, it was an uncomfortable task for which they lacked the necessary skills to provide immediate support to patients at the time of diagnosis.</p>
<p>Conclusion
The introduction of case finding/screening for depression into routine chronic illness management is not straightforward. Routinized case finding/screening for depression can be implemented in ways that may be counterproductive to engagement (particularly by nurses), with the mental health needs of patients living with long term conditions. If case finding/screening or engagement with mental health problems is to be promoted, primary care nurses require more training to increase their confidence in raising and dealing with mental health issues and GPs and nurses need to work collectively to develop the relational work required to promote cognitive participation in case finding/screening.</p>
Kinematic modelling of the Milky Way using the RAVE and GCS stellar surveys
We investigate the kinematic parameters of the Milky Way disc using the RAVE
and GCS stellar surveys. We do this by fitting a kinematic model to the data
taking the selection function of the data into account. For stars in the GCS we
use all phase-space coordinates, but for RAVE stars we use only . Using MCMC technique, we investigate the full posterior distributions
of the parameters given the data. We investigate the `age-velocity dispersion'
relation for the three kinematic components
(), the radial dependence of the velocity
dispersions, the Solar peculiar motion (), the
circular speed at the Sun and the fall of mean azimuthal motion with
height above the mid-plane. We confirm that the Besan\c{c}on-style Gaussian
model accurately fits the GCS data, but fails to match the details of the more
spatially extended RAVE survey. In particular, the Shu distribution function
(DF) handles non-circular orbits more accurately and provides a better fit to
the kinematic data. The Gaussian distribution function not only fits the data
poorly but systematically underestimates the fall of velocity dispersion with
radius. We find that correlations exist between a number of parameters, which
highlights the importance of doing joint fits. The large size of the RAVE
survey, allows us to get precise values for most parameters. However, large
systematic uncertainties remain, especially in and . We
find that, for an extended sample of stars, is underestimated by as
much as if the vertical dependence of the mean azimuthal motion is
neglected. Using a simple model for vertical dependence of kinematics, we find
that it is possible to match the Sgr A* proper motion without any need for
being larger than that estimated locally by surveys like GCS.Comment: 27 pages, 13 figures, accepted for publication in Ap
The phase diagram of the lattice Calogero-Sutherland model
We introduce a {\it lattice} version of the Calogero Sutherland model adapted
to describe pairwise interacting steps with discrete positions on a
vicinal surface. The configurational free energy is obtained within a transfer
matrix method. The full phase diagram for attractive and for repulsive
interaction is deduced. For attraction, critical temperatures of faceting
transitions are found to depend on step density.Comment: latex PRBCalogSuth.tex, 6 files, 4 pages [SPEC-S00/900
Protein for Life: Review of Optimal Protein Intake, Sustainable Dietary Sources and the Effect on Appetite in Ageing Adults
With an ageing population, dietary approaches to promote health and independence later in life are needed. In part, this can be achieved by maintaining muscle mass and strength as people age. New evidence suggests that current dietary recommendations for protein intake may be insufficient to achieve this goal and that individuals might benefit by increasing their intake and frequency of consumption of high-quality protein. However, the environmental effects of increasing animal-protein production are a concern, and alternative, more sustainable protein sources should be considered. Protein is known to be more satiating than other macronutrients, and it is unclear whether diets high in plant proteins affect the appetite of older adults as they should be recommended for individuals at risk of malnutrition. The review considers the protein needs of an ageing population (>40 years old), sustainable protein sources, appetite-related implications of diets high in plant proteins, and related areas for future research
The RAVE survey: the Galactic escape speed and the mass of the Milky Way
We construct new estimates on the Galactic escape speed at various
Galactocentric radii using the latest data release of the Radial Velocity
Experiment (RAVE DR4). Compared to previous studies we have a database larger
by a factor of 10 as well as reliable distance estimates for almost all stars.
Our analysis is based on the statistical analysis of a rigorously selected
sample of 90 high-velocity halo stars from RAVE and a previously published data
set. We calibrate and extensively test our method using a suite of cosmological
simulations of the formation of Milky Way-sized galaxies. Our best estimate of
the local Galactic escape speed, which we define as the minimum speed required
to reach three virial radii , is km/s (90%
confidence) with an additional 5% systematic uncertainty, where is
the Galactocentric radius encompassing a mean over-density of 340 times the
critical density for closure in the Universe. From the escape speed we further
derive estimates of the mass of the Galaxy using a simple mass model with two
options for the mass profile of the dark matter halo: an unaltered and an
adiabatically contracted Navarro, Frenk & White (NFW) sphere. If we fix the
local circular velocity the latter profile yields a significantly higher mass
than the un-contracted halo, but if we instead use the statistics on halo
concentration parameters in large cosmological simulations as a constraint we
find very similar masses for both models. Our best estimate for , the
mass interior to (dark matter and baryons), is M (corresponding to M). This estimate is in good agreement with recently published
independent mass estimates based on the kinematics of more distant halo stars
and the satellite galaxy Leo I.Comment: 16 pages, 15 figures; accepted for publication in Astronomy &
Astrophysic
Single-lined Spectroscopic Binary Star Candidates in the RAVE Survey
Repeated spectroscopic observations of stars in the Radial Velocity
Experiment (RAVE) database are used to identify and examine single-lined binary
(SB1) candidates. The RAVE latest internal database (VDR3) includes radial
velocities, atmospheric and other parameters for approximately quarter million
of different stars with little less than 300,000 observations. In the sample of
~20,000 stars observed more than once, 1333 stars with variable radial
velocities were identified. Most of them are believed to be SB1 candidates. The
fraction of SB1 candidates among stars with several observations is between 10%
and 15% which is the lower limit for binarity among RAVE stars. Due to the
distribution of time spans between the re-observation that is biased towards
relatively short timescales (days to weeks), the periods of the identified SB1
candidates are most likely in the same range. Because of the RAVE's narrow
magnitude range most of the dwarf candidates belong to the thin Galactic disk
while the giants are part of the thick disk with distances extending to up to a
few kpc. The comparison of the list of SB1 candidates to the VSX catalog of
variable stars yielded several pulsating variables among the giant population
with the radial velocity variations of up to few tens of km/s. There are 26
matches between the catalog of spectroscopic binary orbits (SB9) and the whole
RAVE sample for which the given periastron time and the time of RAVE
observation were close enough to yield a reliable comparison. RAVE measurements
of radial velocities of known spectroscopic binaries are consistent with their
published radial velocity curves.Comment: 10 pages, 7 figures, accepted for publication in A
New distances to RAVE stars
Probability density functions are determined from new stellar parameters for
the distance moduli of stars for which the RAdial Velocity Experiment (RAVE)
has obtained spectra with S/N>=10. Single-Gaussian fits to the pdf in distance
modulus suffice for roughly half the stars, with most of the other half having
satisfactory two-Gaussian representations. As expected, early-type stars rarely
require more than one Gaussian. The expectation value of distance is larger
than the distance implied by the expectation of distance modulus; the latter is
itself larger than the distance implied by the expectation value of the
parallax. Our parallaxes of Hipparcos stars agree well with the values measured
by Hipparcos, so the expectation of parallax is the most reliable distance
indicator. The latter are improved by taking extinction into account. The
effective temperature absolute-magnitude diagram of our stars is significantly
improved when these pdfs are used to make the diagram. We use the method of
kinematic corrections devised by Schoenrich, Binney & Asplund to check for
systematic errors for general stars and confirm that the most reliable distance
indicator is the expectation of parallax. For cool dwarfs and low-gravity
giants tends to be larger than the true distance by up to 30 percent. The
most satisfactory distances are for dwarfs hotter than 5500 K. We compare our
distances to stars in 13 open clusters with cluster distances from the
literature and find excellent agreement for the dwarfs and indications that we
are over-estimating distances to giants, especially in young clusters.Comment: 20 pages accepted by MNRAS. Minor changes to the submitted versio
Transporter gene acquisition and innovation in the evolution of Microsporidia intracellular parasites.
The acquisition of genes by horizontal transfer can impart entirely new biological functions and provide an important route to major evolutionary innovation. Here we have used ancient gene reconstruction and functional assays to investigate the impact of a single horizontally transferred nucleotide transporter into the common ancestor of the Microsporidia, a major radiation of intracellular parasites of animals and humans. We show that this transporter provided early microsporidians with the ability to steal host ATP and to become energy parasites. Gene duplication enabled the diversification of nucleotide transporter function to transport new substrates, including GTP and NAD+, and to evolve the proton-energized net import of nucleotides for nucleic acid biosynthesis, growth and replication. These innovations have allowed the loss of pathways for mitochondrial and cytosolic energy generation and nucleotide biosynthesis that are otherwise essential for free-living eukaryotes, resulting in the highly unusual and reduced cells and genomes of contemporary Microsporidia
Exploring the Morphology of RAVE Stellar Spectra
The RAdial Velocity Experiment (RAVE) is a medium resolution R~7500
spectroscopic survey of the Milky Way which already obtained over half a
million stellar spectra. They present a randomly selected magnitude-limited
sample, so it is important to use a reliable and automated classification
scheme which identifies normal single stars and discovers different types of
peculiar stars. To this end we present a morphological classification of
350,000 RAVE survey stellar spectra using locally linear embedding, a
dimensionality reduction method which enables representing the complex spectral
morphology in a low dimensional projected space while still preserving the
properties of the local neighborhoods of spectra. We find that the majority of
all spectra in the database ~90-95% belong to normal single stars, but there is
also a significant population of several types of peculiars. Among them the
most populated groups are those of various types of spectroscopic binary and
chromospherically active stars. Both of them include several thousands of
spectra. Particularly the latter group offers significant further investigation
opportunities since activity of stars is a known proxy of stellar ages.
Applying the same classification procedure to the sample of normal single stars
alone shows that the shape of the projected manifold in two dimensional space
correlates with stellar temperature, surface gravity and metallicity.Comment: 28 pages, 11 figures, accepted for publication in ApJ
Genetically engineered minipigs model the major clinical features of human neurofibromatosis type 1.
Neurofibromatosis Type 1 (NF1) is a genetic disease caused by mutations in Neurofibromin 1 (NF1). NF1 patients present with a variety of clinical manifestations and are predisposed to cancer development. Many NF1 animal models have been developed, yet none display the spectrum of disease seen in patients and the translational impact of these models has been limited. We describe a minipig model that exhibits clinical hallmarks of NF1, including café au lait macules, neurofibromas, and optic pathway glioma. Spontaneous loss of heterozygosity is observed in this model, a phenomenon also described in NF1 patients. Oral administration of a mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor suppresses Ras signaling. To our knowledge, this model provides an unprecedented opportunity to study the complex biology and natural history of NF1 and could prove indispensable for development of imaging methods, biomarkers, and evaluation of safety and efficacy of NF1-targeted therapies
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