376 research outputs found
Predictors of Readiness to Quit Among a Diverse Sample of Sexual Minority Male Smokers
ABSTRACT
Introduction: Readiness to quit smoking - a pattern of attitudes, intentions, and behaviors that reflect a likelihood of engaging in cessation activitiesâis a useful heuristic for understanding smoking disparities based on sexual orientation. This study examined demographic, tobacco-use patterns, psychosocial and cognitive factors associated with readiness to quit among gay and bisexual male smokers.
Methods: A cross-sectional survey was conducted as part of a larger Tobacco Elimination and Control Collaboration (Q-TECC) initiative in the lesbian, gay, bisexual, and transgender (LGBT) community. Readiness to quit was measured by a composite score created from four variables (motivation to quit, importance of quitting, plan to quit, and confidence in quitting) (alpha=.87, M=3.42, SD=.96, range 1-5).
Results: The sexual minority smokers in the sample (N=208; M=33 years) were racially/ethnically diverse. Latino men had significantly lower levels of readiness to quit compared to African American and White men. Hierarchical linear regression analyses were performed to explore the relative contributions of sociodemographic, tobacco-use patterns, psychosocial and cognitive factors on Readiness to Quit. In the final model, the following variables were associated with readiness to quit scores: Latino ethnicity, fewer quit attempts, positive expectancies for the beneficial effects of smoking, and lower perceived importance of smoking as an important LGBT health issue. None of the psychosocial factors were associated with readiness to quit.
Discussion: Readiness to quit scores were largely predicted by modifiable attitudes, behaviors, and expectancies. Study findings have implications for improving outreach and awareness and for the development of effective treatment approaches
Time Delay Effects on Coupled Limit Cycle Oscillators at Hopf Bifurcation
We present a detailed study of the effect of time delay on the collective
dynamics of coupled limit cycle oscillators at Hopf bifurcation. For a simple
model consisting of just two oscillators with a time delayed coupling, the
bifurcation diagram obtained by numerical and analytical solutions shows
significant changes in the stability boundaries of the amplitude death, phase
locked and incoherent regions. A novel result is the occurrence of amplitude
death even in the absence of a frequency mismatch between the two oscillators.
Similar results are obtained for an array of N oscillators with a delayed mean
field coupling and the regions of such amplitude death in the parameter space
of the coupling strength and time delay are quantified. Some general analytic
results for the N tending to infinity (thermodynamic) limit are also obtained
and the implications of the time delay effects for physical applications are
discussed.Comment: 20 aps formatted revtex pages (including 13 PS figures); Minor
changes over the previous version; To be published in Physica
TGF beta 1 and biglycan, decorin, and fibromodulin metabolism in canine cartilage
AbstractObjective: Small proteoglycans (PGs) may accumulate in late stage osteoarthritis even as aggrecan is lost. It is not clear what role transforming growth factor (TGF) beta has in this accumulation. Our goal was to investigate the ability of TGF beta 1 to modulate the synthesis and accumulation of decorin, biglycan, and fibromodulin in cartilage explants cultured under conditions in which aggrecan synthesis remains relatively constant.Design: Articular cartilage was cultured in the presence or absence of 4ng/ml TGF beta 1 for up to 16 days. Material extracted from cartilage was assayed for 35SO4-large and small PGs and for total endogenous decorin, biglycan and fibromodulin.Results: The synthesis of 35SO4-small PGs increased during the 16 days in culture in response to TGF beta 1, but declined in control cultures. The difference in 35SO4-decorin between TGF beta 1 and control samples reached nine-fold after 16 days, while the difference in total endogenous decorin was less than 1.5-fold. 35SO4-decorin, which was present in TGF beta 1-treated cultures had an identical core protein, but a longer glycosaminoglycan chain than that of decorin in control cultures. No significant differences in endogenous biglycan were detected, but accumulation of fibromodulin in TGF beta 1 explants exceeded fibromodulin in controls, on average, by 3.8-fold. Fibromodulin was present in cartilage in both keratan sulfate- and non-sulfated oligosaccharide-substituted forms.Conclusions: The accumulation of each of the three small PGs was affected to a different extent in response to TGF beta 1. Of the three, fibromodulin content was most rapidly augmented in response to TGF beta 1
Dynamics of a Limit Cycle Oscillator under Time Delayed Linear and Nonlinear Feedbacks
We study the effects of time delayed linear and nonlinear feedbacks on the
dynamics of a single Hopf bifurcation oscillator. Our numerical and analytic
investigations reveal a host of complex temporal phenomena such as phase slips,
frequency suppression, multiple periodic states and chaos. Such phenomena are
frequently observed in the collective behavior of a large number of coupled
limit cycle oscillators. Our time delayed feedback model offers a simple
paradigm for obtaining and investigating these temporal states in a single
oscillator.We construct a detailed bifurcation diagram of the oscillator as a
function of the time delay parameter and the driving strengths of the feedback
terms. We find some new states in the presence of the quadratic nonlinear
feedback term with interesting characteristics like birhythmicity, phase
reversals, radial trapping, phase jumps and spiraling patterns in the amplitude
space. Our results may find useful applications in physical, chemical or
biological systems.Comment: VERSION 4: Fig. 10(d) added, an uncited reference removed; (To appear
in Physica D) (17 pages, 21 figures, two column, aps RevTeX); VERSION 3:
Revised. In Section 2, small tau approximation added; Section 3 is divided
into subsections; periodic solution discussed in detail; Figs. 7 and 11
discarded; Figs. 12 and 14 altered; three new figures (now Figs. 10, 11 and
21) added. VERSION 2: Figs. 1 and 2 replace
Promotion of tobacco use cessation for lesbian, gay, bisexual, and transgender people: A systematic review
Lesbian, gay, bisexual, and transgender (LGBT) people are at increased risk for the adverse effects of tobacco use given their high prevalence of use, especially smoking. Evidence regarding cessation is limited. To determine if efficacious interventions are available and to aid the development of interventions, a systematic review was conducted of gray and peer-reviewed literature describing clinical, community, and policy interventions as well as knowledge, attitudes, and behaviors regarding tobacco use cessation among LGBT people
Numerical semigroups with large embedding dimension satisfy Wilf's conjecture
We give an affirmative answer to Wilf's conjecture for numerical semigroups
satisfying 2 \nu \geq m, where \nu and m are respectively the embedding
dimension and the multiplicity of a semigroup. The conjecture is also proved
when m \leq 8 and when the semigroup is generated by a generalized arithmetic
sequence.Comment: 13 page
Analysing livestock network data for infectious disease control: an argument for routine data collection in emerging economies
Livestock movements are an important mechanism of infectious disease transmission. Where these are well recorded, network analysis tools have been used to successfully identify system properties, highlight vulnerabilities to transmission, and inform targeted surveillance and control. Here we highlight the main uses of network properties in understanding livestock disease epidemiology and discuss statistical approaches to infer network characteristics from biased or fragmented datasets. We use a âhurdle modelâ approach that predicts (i) the probability of movement and (ii) the number of livestock moved to generate synthetic âcompleteâ networks of movements between administrative wards, exploiting routinely collected government movement permit data from northern Tanzania. We demonstrate that this model captures a significant amount of the observed variation. Combining the cattle movement network with a spatial between-ward contact layer, we create a multiplex, over which we simulated the spread of âfastâ (R0 = 3) and âslowâ (R0 = 1.5) pathogens, and assess the effects of random versus targeted disease control interventions (vaccination and movement ban). The targeted interventions substantially outperform those randomly implemented for both fast and slow pathogens. Our findings provide motivation to encourage routine collection and centralization of movement data to construct representative networks.
This article is part of the theme issue âModelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and controlâ. This theme issue is linked with the earlier issue âModelling infectious disease outbreaks in humans, animals and plants: approaches and important themesâ
SRAO CO Observation of 11 Supernova Remnants in l = 70 to 190 deg
We present the results of 12CO J = 1-0 line observations of eleven Galactic
supernova remnants (SNRs) obtained using the Seoul Radio Astronomy Observatory
(SRAO) 6-m radio telescope. The observation was made as a part of the SRAO CO
survey of SNRs between l = 70 and 190 deg, which is intended to identify SNRs
interacting with molecular clouds. The mapping areas for the individual SNRs
are determined to cover their full extent in the radio continuum. We used
halfbeam grid spacing (60") for 9 SNRs and full-beam grid spacing (120") for
the rest. We detected CO emission towards most of the remnants. In six SNRs,
molecular clouds showed a good spatial relation with their radio morphology,
although no direct evidence for the interaction was detected. Two SNRs are
particularly interesting: G85.4+0.7, where there is a filamentary molecular
cloud along the radio shell, and 3C434.1, where a large molecular cloud appears
to block the western half of the remnant. We briefly summarize the results
obtained for individual SNRs.Comment: Accepted for publication in Astrophysics & Space Science. 12 pages,
12 figures, and 3 table
Tune in to your emotions: a robust personalized affective music player
The emotional power of music is exploited in a personalized affective music player (AMP) that selects music for mood enhancement. A biosignal approach is used to measure listenersâ personal emotional reactions to their own music as input for affective user models. Regression and kernel density estimation are applied to model the physiological changes the music elicits. Using these models, personalized music selections based on an affective goal state can be made. The AMP was validated in real-world trials over the course of several weeks. Results show that our models can cope with noisy situations and handle large inter-individual differences in the music domain. The AMP augments music listening where its techniques enable automated affect guidance. Our approach provides valuable insights for affective computing and user modeling, for which the AMP is a suitable carrier application
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