13,131 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>
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
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 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
Symbiotic starburst-black hole AGN -- I. Isothermal hydrodynamics of the mass-loaded ISM
Compelling evidence associates the nuclei of active galaxies and massive
starbursts. The symbiosis between a compact nuclear starburst stellar cluster
and a massive black hole can self-consistently explain the properties of active
nuclei. The young stellar cluster has a profound effect on the most important
observable properties of active galaxies through its gravity, and by mass
injection through stellar winds, supernovae and stellar collisions. Mass
injection generates a nuclear ISM which flows under gravitational and radiative
forces until it leaves the nucleus or is accreted onto the black hole or
accretion disc.
The radiative force exerted by the black hole--accretion disc radiation field
is not spherically symmetric. This results in complex flows in which regions of
inflow can coexist with high Mach number outflowing winds and hydrodynamic
jets. We present two-dimensional hydrodynamic models of such nISM flows, which
are highly complex and time variable. Shocked shells, jets and explosive
bubbles are produced, with bipolar winds driving out from the nucleus. Our
results graphically illustrate why broad emission line studies have
consistently failed to identify any simple, global flow geometry. The real
structure of the flows is _inevitably_ yet more complex.Comment: 51 pages, 85 postscript figures, Latex, using MNRAS macros, to be
published in MNRAS. Postscript will full resolution pictures and mpeg
simulations available via http://ast.leeds.ac.uk/~rjrw/agn.htm
A combined XAS and XRD Study of the High-Pressure Behaviour of GaAsO4 Berlinite
Combined X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD)
experiments have been carried out on GaAsO4 (berlinite structure) at high
pressure and room temperature. XAS measurements indicate four-fold to six-fold
coordination changes for both cations. The two local coordination
transformations occur at different rates but appear to be coupled. A reversible
transition to a high pressure crystalline form occurs around 8 GPa. At a
pressure of about 12 GPa, the system mainly consists of octahedral gallium
atoms and a mixture of arsenic in four-fold and six-fold coordinations. A
second transition to a highly disordered material with both cations in six-fold
coordination occurs at higher pressures and is irreversible.Comment: 8 pages, 5 figures, LaTeX2
The Intermediate Filament Cytoskeleton of Macrophages
This study characterizes two-and three-dimensional ultrastructure and surface topography of polymerized networks of intermediate filaments (IF) isolated from mouse peritoneal macrophages. Isolated IF bound to monoclonal anti-IF antibodies in enzyme-linked immunosorbent assays. Immunogold labeling of IF with specific antibodies revealed that epitopes are distributed along filaments particularly at junctions where filaments interconnect. Networks of IF, viewed by scanning electron microscopy, organized as ropelike groups of interconnecting filaments which swirl and encircle each other to form three-dimensional lattices containing ellipsoidal-, circular-, and vacuole-shaped cavities. Cavity diameters were similar in size to organelles and vacuoles; diameters were grouped as small (12-288 nm), medium (0.3-1.7 μm), and large (2-3 μm). The walls of the cavities appeared as beaded structures with alternating globular and linear regions. Linear regions were 14 nm. Repeat distances taken from the central axis of globular regions were 23-27 nm. The lattice organization of IF observed in vitro was similar to images seen in vivo in Triton-insoluble cytoskeletons immunofluorescently labeled with specific antibodies. In whole cells processed for TEM, swirling bundles of IF were found encircling membranous vacuoles. Based on the lattice architecture of IF, cavity dimensions, and IF location, we postulate that intermediate filaments may function in the mechanical and spatial distribution of vacuoles in the cell cytoplasm
The RAVE Survey: Constraining the Local Galactic Escape Speed
We report new constraints on the local escape speed of our Galaxy. Our
analysis is based on a sample of high velocity stars from the RAVE survey and
two previously published datasets. We use cosmological simulations of disk
galaxy formation to motivate our assumptions on the shape of the velocity
distribution, allowing for a significantly more precise measurement of the
escape velocity compared to previous studies. We find that the escape velocity
lies within the range 498\kms < \ve < 608 \kms (90 per cent confidence), with
a median likelihood of 544\kms. The fact that \ve^2 is significantly
greater than 2\vc^2 (where \vc=220\kms is the local circular velocity)
implies that there must be a significant amount of mass exterior to the Solar
circle, i.e. this convincingly demonstrates the presence of a dark halo in the
Galaxy. For a simple isothermal halo, one can calculate that the minimum radial
extent is kpc. We use our constraints on \ve to determine the mass
of the Milky Way halo for three halo profiles. For example, an adiabatically
contracted NFW halo model results in a virial mass of
and virial radius of
kpc (90 per cent confidence). For this model the circular
velocity at the virial radius is 142^{+31}_{-21}\kms. Although our halo
masses are model dependent, we find that they are in good agreement with each
other.Comment: 19 pages, 9 figures, MNRAS (accepted). v2 incorporates minor cosmetic
revisions which have no effect on the results or conclusion
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
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