137 research outputs found
Tailored versus generic knowledge brokering to integrate mood management into smoking cessation interventions in primary care settings : Protocol for a cluster randomized controlled trial
Background: Both tobacco smoking and depression are major public health problems associated with high morbidity and mortality. In addition, individuals with depression are almost twice as likely to smoke and less likely to achieve smoking cessation. In the Smoking Treatment for Ontario Patients program, an established smoking cessation program in Ontario, Canada, 38% of smokers in primary care settings have current or past depression with 6-month quit rates that are significantly lower than those without depression (33% versus 40%, P<.001). Integrating self-help mood management (eg, relaxation exercises and mood monitoring) with smoking cessation treatment increases long-term quit rates by 12%-20%. However, integration in real-world settings has not been reported. It is unclear which knowledge translation strategy would be more effective for motivating clinicians to provide resources on mood management to eligible patients. Objective: The objectives of this study are to investigate the following comparisons among depressed smokers enrolled in a smoking cessation program: 1) the effectiveness of generalized, exclusively email-based prompts versus a personalized knowledge broker in implementing mood management interventions; 2) the effectiveness of the two knowledge translation strategies on smoking quit rates; and 3) the incremental costs of the two knowledge translation strategies on the implementation of mood management interventions. Methods: The study design is a cluster randomized controlled trial of Family Health Teams participating in the Smoking Treatment for Ontario Patients program. Family Health Teams will be randomly allocated 1:1 to receive either generalized messages (related to depression and smoking) exclusively via email (group A) or be assigned a knowledge broker who provides personalized support through phone- and email-based check-ins (group B). The primary outcome, measured at the site level, is the proportion of eligible baseline visits that result in the provision of the mood management intervention to eligible patients. Results: Recruitment for the primary outcome of this study will be completed in 2018/2019. Results will be reported in 2019/2020. Conclusions: This study will address the knowledge gap in the implementation strategies (ie, email-based prompts versus a knowledge broker) of mood management interventions for smokers with depression in primary care settings. Trial Registration: ClinicalTrials.gov NCT03130998; https://clinicaltrials.gov/ct2/show/NCT03130998 (Archived on WebCite at www.webcitation.org/6ylyS6RTe)
Dynamical stability of a thermally stratified intracluster medium with anisotropic momentum and heat transport
In weakly-collisional plasmas such as the intracluster medium (ICM), heat and
momentum transport become anisotropic with respect to the local magnetic field
direction. Anisotropic heat conduction causes the slow magnetosonic wave to
become buoyantly unstable to the magnetothermal instability (MTI) when the
temperature increases in the direction of gravity and to the heat-flux--driven
buoyancy instability (HBI) when the temperature decreases in the direction of
gravity. The local changes in magnetic field strength that attend these
instabilities cause pressure anisotropies that viscously damp motions parallel
to the magnetic field. In this paper we employ a linear stability analysis to
elucidate the effects of anisotropic viscosity (i.e. Braginskii pressure
anisotropy) on the MTI and HBI. By stifling the convergence/divergence of
magnetic field lines, pressure anisotropy significantly affects how the ICM
interacts with the temperature gradient. Instabilities which depend upon the
convergence/divergence of magnetic field lines to generate unstable buoyant
motions (the HBI) are suppressed over much of the wavenumber space, whereas
those which are otherwise impeded by field-line convergence/divergence (the
MTI) are strengthened. As a result, the wavenumbers at which the HBI survives
largely unsuppressed in the ICM have parallel components too small to
rigorously be considered local. This is particularly true as the magnetic field
becomes more and more orthogonal to the temperature gradient. In contrast, the
fastest-growing MTI modes are unaffected by anisotropic viscosity. However, we
find that anisotropic viscosity couples slow and Alfven waves in such a way as
to buoyantly destabilise Alfvenic fluctuations when the temperature increases
in the direction of gravity. Consequently, many wavenumbers previously
considered MTI-stable or slow-growing are in fact maximally unstable.
(abridged)Comment: 15 pages, 7 figures, accepted by MNRAS; typos fixed and minor
corrections made; color figures available at
http://www-thphys.physics.ox.ac.uk/people/kunz/Kunz11_colorfigs.pd
The HBI in a quasi-global model of the intracluster medium
In this paper we investigate how convective instabilities influence heat
conduction in the intracluster medium (ICM) of cool-core galaxy clusters. The
ICM is a high-beta, weakly collisional plasma in which the transport of
momentum and heat is aligned with the magnetic field. The anisotropy of heat
conduction, in particular, gives rise to instabilities that can access energy
stored in a temperature gradient of either sign. We focus on the heat-flux
buoyancy-driven instability (HBI), which feeds on the outwardly increasing
temperature profile of cluster cool cores. Our aim is to elucidate how the
global structure of a cluster impacts on the growth and morphology of the
linear HBI modes when in the presence of Braginskii viscosity, and ultimately
on the ability of the HBI to thermally insulate cores. We employ an idealised
quasi-global model, the plane-parallel atmosphere, which captures the essential
physics -- e.g. the global radial profile of the cluster -- while letting the
problem remain analytically tractable. Our main result is that the dominant HBI
modes are localised to the the innermost (~<20%) regions of cool cores. It is
then probable that, in the nonlinear regime, appreciable field-line insulation
will be similarly localised. Thus, while radio-mode feedback appears necessary
in the central few tens of kpc, heat conduction may be capable of offsetting
radiative losses throughout most of a cool core over a significant fraction of
the Hubble time. Finally, our linear solutions provide a convenient numerical
test for the nonlinear codes that tackle the saturation of such convective
instabilities in the presence of anisotropic transport.Comment: MNRAS, in press; minor modifications from v
Evolution of magnetized, differentially rotating neutron stars: Simulations in full general relativity
We study the effects of magnetic fields on the evolution of differentially
rotating neutron stars, which can form in stellar core collapse or binary
neutron star coalescence. Magnetic braking and the magnetorotational
instability (MRI) both redistribute angular momentum; the outcome of the
evolution depends on the star's mass and spin. Simulations are carried out in
axisymmetry using our recently developed codes which integrate the coupled
Einstein-Maxwell-MHD equations. For initial data, we consider three categories
of differentially rotating, equilibrium configurations, which we label normal,
hypermassive and ultraspinning. Hypermassive stars have rest masses exceeding
the mass limit for uniform rotation. Ultraspinning stars are not hypermassive,
but have angular momentum exceeding the maximum for uniform rotation at the
same rest mass. We show that a normal star will evolve to a uniformly rotating
equilibrium configuration. An ultraspinning star evolves to an equilibrium
state consisting of a nearly uniformly rotating central core, surrounded by a
differentially rotating torus with constant angular velocity along magnetic
field lines, so that differential rotation ceases to wind the magnetic field.
In addition, the final state is stable against the MRI, although it has
differential rotation. For a hypermassive neutron star, the MHD-driven angular
momentum transport leads to catastrophic collapse of the core. The resulting
rotating black hole is surrounded by a hot, massive, magnetized torus
undergoing quasistationary accretion, and a magnetic field collimated along the
spin axis--a promising candidate for the central engine of a short gamma-ray
burst. (Abridged)Comment: 27 pages, 30 figure
Managing Injuries of the Neck Trial (MINT) : design of a randomised controlled trial of treatments for whiplash associated disorders
Background: A substantial proportion of patients with whiplash injuries develop chronic
symptoms. However, the best treatment of acute injuries to prevent long-term problems is
uncertain. A stepped care treatment pathway has been proposed, in which patients are given advice
and education at their initial visit to the emergency department (ED), followed by review at three
weeks and physiotherapy for those with persisting symptoms. MINT is a two-stage randomised
controlled trial to evaluate two components of such a pathway: 1. use of The Whiplash Book versus
usual advice when patients first attend the emergency department; 2. referral to physiotherapy
versus reinforcement of advice for patients with continuing symptoms at three weeks.
Methods: Evaluation of the Whiplash Book versus usual advice uses a cluster randomised design
in emergency departments of eight NHS Trusts. Eligible patients are identified by clinicians in
participating emergency departments and are sent a study questionnaire within a week of their ED
attendance. Three thousand participants will be included. Patients with persisting symptoms three
weeks after their ED attendance are eligible to join an individually randomised study of
physiotherapy versus reinforcement of the advice given in ED. Six hundred participants will be
randomised. Follow-up is at 4, 8 and 12 months after their ED attendance. Primary outcome is the
Neck Disability Index (NDI), and secondary outcomes include quality of life and time to return to
work and normal activities. An economic evaluation is being carried out.
Conclusion: This paper describes the protocol and operational aspects of a complex intervention
trial based in NHS emergency and physiotherapy departments, evaluating two components of a
stepped-care approach to the treatment of whiplash injuries. The trial uses two randomisations,
with the first stage being cluster randomised and the second individually randomised
Kepler eclipsing binary stars. VII. the catalogue of eclipsing binaries found in the entire Kepler data set
The primary Kepler Mission provided nearly continuous monitoring of ~200,000 objects with unprecedented photometric precision. We present the final catalog of eclipsing binary systems within the 105 deg2 Kepler field of view. This release incorporates the full extent of the data from the primary mission (Q0-Q17 Data Release). As a result, new systems have been added, additional false positives have been removed, ephemerides and principal parameters have been recomputed, classifications have been revised to rely on analytical models, and eclipse timing variations have been computed for each system. We identify several classes of systems including those that exhibit tertiary eclipse events, systems that show clear evidence of additional bodies, heartbeat systems, systems with changing eclipse depths, and systems exhibiting only one eclipse event over the duration of the mission. We have updated the period and galactic latitude distribution diagrams and included a catalog completeness evaluation. The total number of identified eclipsing and ellipsoidal binary systems in the Kepler field of view has increased to 2878, 1.3% of all observed Kepler targets
Bridging the gap: disk formation in the Class 0 phase with ambipolar diffusion and Ohmic dissipation
Context: Ideal MHD simulations have revealed catastrophic magnetic braking
(MB) in the protostellar phase, which prevents the formation of a centrifugal
disk around a nascent protostar. Aims: We determine if non-ideal MHD, including
the effects of ambipolar diffusion and Ohmic dissipation determined from a
detailed chemical network model, allows for disk formation at the earliest
stages of star formation (SF). Methods: We employ the axisymmetric thin-disk
approximation in order to resolve a dynamic range of 9 orders of magnitude in
length and 16 in density, while also calculating partial ionization using up to
19 species in a detailed chemical equilibrium model. MB is applied using a
steady-state approximation, and a barotropic relation is used to capture the
thermal evolution. Results: We resolve the formation of the first and second
cores, with expansion waves at the periphery of each, a magnetic diffusion
shock, and prestellar infall profiles at larger radii. Power-law profiles in
each region can be understood analytically. After the formation of the second
core, centrifugal support rises rapidly and a low-mass disk of radius ~10 R_Sun
is formed, when the second core has mass ~0.001 M_Sun. The mass-to-flux ratio
is ~10,000 times the critical value in the central region. Conclusions: A small
centrifugal disk can form in the earliest stage of SF, due to a shut-off of MB
caused by magnetic field dissipation in the first core region. There is enough
angular momentum loss to allow the second collapse to occur directly, and a
low-mass stellar core to form with a surrounding disk. The disk mass and size
will depend upon how the angular momentum transport mechanisms within the disk
can keep up with mass infall onto the disk. We estimate that the disk will
remain <~10 AU, undetectable even by ALMA, in the early Class 0 phase.Comment: 19 pages, 17 figures. Accepted for publication at Astronomy &
Astrophysic
Auditory Spatial Acuity Approximates the Resolving Power of Space-Specific Neurons
The relationship between neuronal acuity and behavioral performance was assessed in the barn owl (Tyto alba), a nocturnal raptor renowned for its ability to localize sounds and for the topographic representation of auditory space found in the midbrain. We measured discrimination of sound-source separation using a newly developed procedure involving the habituation and recovery of the pupillary dilation response. The smallest discriminable change of source location was found to be about two times finer in azimuth than in elevation. Recordings from neurons in its midbrain space map revealed that their spatial tuning, like the spatial discrimination behavior, was also better in azimuth than in elevation by a factor of about two. Because the PDR behavioral assay is mediated by the same circuitry whether discrimination is assessed in azimuth or in elevation, this difference in vertical and horizontal acuity is likely to reflect a true difference in sensory resolution, without additional confounding effects of differences in motor performance in the two dimensions. Our results, therefore, are consistent with the hypothesis that the acuity of the midbrain space map determines auditory spatial discrimination
Using data linkage to electronic patient records to assess the validity of selected mental health diagnoses in English Hospital Episode Statistics (HES)
<div><p>Background</p><p>Administrative data can be used to support research, such as in the UK Biobank. Hospital Episode Statistics (HES) are national data for England that include contain ICD-10 diagnoses for inpatient mental healthcare episodes, but the validity of these diagnoses for research purposes has not been assessed.</p><p>Methods</p><p>250 peoples' HES records were selected based on a HES recorded inpatient stay at the South London and Maudsley NHS Foundation Trust with a diagnosis of schizophrenia, a wider schizophrenia spectrum disorder, bipolar affective disorder or unipolar depression. A gold-standard research diagnosis was made using Clinical Records Interactive Search pseudonymised electronic patient records using, and the OPCRIT+ algorithm.</p><p>Results</p><p>Positive predictive value at the level of lifetime psychiatric disorder was 100%, and at the level of lifetime diagnosis in the four categories of schizophrenia, wider schizophrenia spectrum, bipolar or unipolar depression was 73% (68–79). Agreement varied by diagnosis, with schizophrenia having the highest PPV at 90% (80–96). Each person had an average of five psychiatric HES records. An algorithm that looked at the last recorded psychiatric diagnosis led to greatest overall agreement with the research diagnosis.</p><p>Discussion</p><p>For people who have a HES record from a psychiatric admission with a diagnosis of schizophrenia spectrum disorder, bipolar affective disorder or unipolar depression, HES records appear to be a good indicator of a mental disorder, and can provide a diagnostic category with reasonable certainty. For these diagnoses, HES records can be an effective way of ascertaining psychiatric diagnosis.</p></div
ApoE Receptor 2 Regulates Synapse and Dendritic Spine Formation
Apolipoprotein E receptor 2 (ApoEr2) is a postsynaptic protein involved in long-term potentiation (LTP), learning, and memory through unknown mechanisms. We examined the biological effects of ApoEr2 on synapse and dendritic spine formation-processes critical for learning and memory.In a heterologous co-culture synapse assay, overexpression of ApoEr2 in COS7 cells significantly increased colocalization with synaptophysin in primary hippocampal neurons, suggesting that ApoEr2 promotes interaction with presynaptic structures. In primary neuronal cultures, overexpression of ApoEr2 increased dendritic spine density. Consistent with our in vitro findings, ApoEr2 knockout mice had decreased dendritic spine density in cortical layers II/III at 1 month of age. We also tested whether the interaction between ApoEr2 and its cytoplasmic adaptor proteins, specifically X11α and PSD-95, affected synapse and dendritic spine formation. X11α decreased cell surface levels of ApoEr2 along with synapse and dendritic spine density. In contrast, PSD-95 increased cell surface levels of ApoEr2 as well as synapse and dendritic spine density.These results suggest that ApoEr2 plays important roles in structure and function of CNS synapses and dendritic spines, and that these roles are modulated by cytoplasmic adaptor proteins X11α and PSD-95
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