3,362 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)
Renormalized field theory and particle density profile in driven diffusive systems with open boundaries
We investigate the density profile in a driven diffusive system caused by a
plane particle source perpendicular to the driving force. Focussing on the case
of critical bulk density we use a field theoretic renormalization
group approach to calculate the density as a function of the distance
from the particle source at first order in (: spatial
dimension). For we find reasonable agreement with the exact solution
recently obtained for the asymmetric exclusion model. Logarithmic corrections
to the mean field profile are computed for with the result for .Comment: 32 pages, RevTex, 4 Postscript figures, to appear in Phys. Rev.
(In)finiteness of Spherically Symmetric Static Perfect Fluids
This work is concerned with the finiteness problem for static, spherically
symmetric perfect fluids in both Newtonian Gravity and General Relativity. We
derive criteria on the barotropic equation of state guaranteeing that the
corresponding perfect fluid solutions possess finite/infinite extent. In the
Newtonian case, for the large class of monotonic equations of state, and in
General Relativity we improve earlier results
Time-ordering and a generalized Magnus expansion
Both the classical time-ordering and the Magnus expansion are well-known in
the context of linear initial value problems. Motivated by the noncommutativity
between time-ordering and time derivation, and related problems raised recently
in statistical physics, we introduce a generalization of the Magnus expansion.
Whereas the classical expansion computes the logarithm of the evolution
operator of a linear differential equation, our generalization addresses the
same problem, including however directly a non-trivial initial condition. As a
by-product we recover a variant of the time ordering operation, known as
T*-ordering. Eventually, placing our results in the general context of
Rota-Baxter algebras permits us to present them in a more natural algebraic
setting. It encompasses, for example, the case where one considers linear
difference equations instead of linear differential equations
Locating the minimum : Approach to equilibrium in a disordered, symmetric zero range process
We consider the dynamics of the disordered, one-dimensional, symmetric zero
range process in which a particle from an occupied site hops to its nearest
neighbour with a quenched rate . These rates are chosen randomly from the
probability distribution , where is the lower cutoff.
For , this model is known to exhibit a phase transition in the steady
state from a low density phase with a finite number of particles at each site
to a high density aggregate phase in which the site with the lowest hopping
rate supports an infinite number of particles. In the latter case, it is
interesting to ask how the system locates the site with globally minimum rate.
We use an argument based on local equilibrium, supported by Monte Carlo
simulations, to describe the approach to the steady state. We find that at
large enough time, the mass transport in the regions with a smooth density
profile is described by a diffusion equation with site-dependent rates, while
the isolated points where the mass distribution is singular act as the
boundaries of these regions. Our argument implies that the relaxation time
scales with the system size as with for and
suggests a different behaviour for .Comment: Revtex, 7 pages including 3 figures. Submitted to Pramana -- special
issue on mesoscopic and disordered system
A Parsec-Scale Study of the 5/15 GHz Spectral Indices of the Compact Radio Sources in M82
Observations of the starburst galaxy, M82, have been made with the VLA in its
A-configuration at 15 GHz and MERLIN at 5 GHz enabling a spectral analysis of
the compact radio structure on a scale of < 0.1'' (1.6 pc). Crucial to these
observations was the inclusion of the Pie Town VLBA antenna, which increased
the resolution of the VLA observations by a factor of ~2. A number of the
weaker sources are shown to have thermal spectra and are identified as HII
regions with emission measures ~10^7 cm^-6 pc. Some of the sources appear to be
optically thick at 5 GHz implying even higher emission measures of ~10^8 cm^-6
pc. The number of compact radio sources in M82 whose origin has been determined
is now 46, of which 30 are supernova related and the remaining 16 are HII
regions. An additional 15 sources are noted, but have yet to be identified,
meaning that the total number of compact sources in M82 is at least 61. Also,
it is shown that the distribution of HII regions is correlated with the
large-scale ionised gas distribution, but is different from the distribution of
supernova remnants. In addition, the brightest HII region at (B1950) 09h 51m
42.21s +69 54' 59.2'' shows a spectral index gradient across its resolved
structure which we attribute to the source becoming optically thick towards its
centre.Comment: Accepted for publication in MNRAS. 15 pages, 9 figure
A deep Chandra observation of the Perseus cluster: shocks and ripples
We present preliminary results from a deep observation lasting almost 200 ks,
of the centre of the Perseus cluster of galaxies around NGC 1275. The X-ray
surface brightness of the intracluster gas beyond the inner 20 kpc, which
contains the inner radio bubbles, is very smooth apart from some low amplitude
quasi-periodic ripples. A clear density jump at a radius of 24 kpc to the NE,
about 10 kpc out from the bubble rim, appears to be due to a weak shock driven
by the northern radio bubble. A similar front may exist round both inner
bubbles but is masked elsewhere by rim emission from bright cooler gas. The
continuous blowing of bubbles by the central radio source, leading to the
propagation of weak shocks and viscously-dissipating sound waves seen as the
observed fronts and ripples, gives a rate of working which balances the
radiative cooling within the inner 50 kpc of the cluster core.Comment: Accepted for publication in MNRAS (minor changes) Higher picture
quality available from http://www-xray.ast.cam.ac.uk/papers/per_200ks.pd
Birkhoff type decompositions and the Baker-Campbell-Hausdorff recursion
We describe a unification of several apparently unrelated factorizations
arisen from quantum field theory, vertex operator algebras, combinatorics and
numerical methods in differential equations. The unification is given by a
Birkhoff type decomposition that was obtained from the Baker-Campbell-Hausdorff
formula in our study of the Hopf algebra approach of Connes and Kreimer to
renormalization in perturbative quantum field theory. There we showed that the
Birkhoff decomposition of Connes and Kreimer can be obtained from a certain
Baker-Campbell-Hausdorff recursion formula in the presence of a Rota-Baxter
operator. We will explain how the same decomposition generalizes the
factorization of formal exponentials and uniformization for Lie algebras that
arose in vertex operator algebra and conformal field theory, and the even-odd
decomposition of combinatorial Hopf algebra characters as well as to the Lie
algebra polar decomposition as used in the context of the approximation of
matrix exponentials in ordinary differential equations.Comment: accepted for publication in Comm. in Math. Phy
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