Contact binaries with additional components. III. The adaptive optics detections

We present results of the CFHT adaptive optics search for companions of a homogeneous group of contact binary stars, as a contribution to our attempts to prove a hypothesis that these binaries require a third star to become so close as observed. In addition to companions directly discovered at separations of >=1", we introduced a new method of AO image analysis utilizing distortions of the AO diffraction ring pattern at separations of 0.07"-1". Very close companions, with separations in the latter range were discovered in systems HV Aqr, OO Aql, CK Boo, XY Leo, BE Scl, and RZ Tau. More distant companions were detected in V402 Aur, AO Cam, V2082 Cyg. Our results provide a contribution to the mounting evidence that the presence of close companions is a very common phenomenon for very close binaries with orbital periods <1 day.Comment: Full Figs.4 and 5 are in http://www.astro.utoronto.ca/~rucinski/Triples3

The dynamical evolution of the circumstellar gas around low-and intermediate-mass stars I: the AGB

We have investigated the dynamical interaction of low- and-intermediate mass stars (from 1 to 5 Msun) with their interstellar medium (ISM). In this first paper, we examine the structures generated by the stellar winds during the Asymptotic Giant Branch (AGB) phase, using a numerical code and the wind history predicted by stellar evolution. The influence of the external ISM is also taken into account. We find that the wind variations associated with the thermal pulses lead to the formation of transient shells with an average lifetime of 20,000 yr, and consequently do not remain recorded in the density or velocity structure of the gas. The formation of shells that survive at the end of the AGB occurs via two main processes: shocks between the shells formed by two consecutive enhancements of the mass-loss or via continuous accumulation of the material ejected by the star in the interaction region with the ISM. Our models show that the mass of the circumstellar envelope increases appreciably due to the ISM material swept up by the wind (up to 70 % for the 1 Msun stellar model). We also point out the importance of the ISM on the deceleration and compression of the external shells. According to our simulations, large regions (up to 2.5 pc) of neutral gas surrounding the molecular envelopes of AGB stars are expected. These large regions of gas are formed from the mass-loss experienced by the star during the AGB evolution.Comment: 43 pages, 15 figures. Accepted for publication in the Astrophysical Journa

Non-specific interstitial pneumonia in cigarette smokers: a CT study

The goal of this study was to seek indirect evidence that smoking is an aetiological factor in some patients with non-specific interstitial pneumonia (NSIP). Ten current and eight ex-smokers with NSIP were compared to controls including 137 current smokers with no known interstitial lung disease and 11 non-smokers with NSIP. Prevalence and extent of emphysema in 18 smokers with NSIP were compared with subjects meeting GOLD criteria for chronic obstructive pulmonary disease (COPD; group A; n = 34) and healthy smokers (normal FEV1; group B; n = 103), respectively. Emphysema was present in 14/18 (77.8%) smokers with NSIP. Emphysema did not differ in prevalence between NSIP patients and group A controls (25/34, 73.5%), but was strikingly more prevalent in NSIP patients than in group B controls (18/103, 17.5%, P < 0.0005). On multiple logistic regression, the likelihood of emphysema increased when NSIP was present (OR = 18.8; 95% CI = 5.3–66.3; P < 0.0005) and with increasing age (OR = 1.04; 95% CI = 0.99–1.11; P = 0.08). Emphysema is as prevalent in smokers with NSIP as in smokers with COPD, and is strikingly more prevalent in these two groups than in healthy smoking controls. The association between NSIP and emphysema provides indirect support for a smoking pathogenesis hypothesis in some NSIP patients

Multi-ancestry study of blood lipid levels identifies four loci interacting with physical activity.

Many genetic loci affect circulating lipid levels, but it remains unknown whether lifestyle factors, such as physical activity, modify these genetic effects. To identify lipid loci interacting with physical activity, we performed genome-wide analyses of circulating HDL cholesterol, LDL cholesterol, and triglyceride levels in up to 120,979 individuals of European, African, Asian, Hispanic, and Brazilian ancestry, with follow-up of suggestive associations in an additional 131,012 individuals. We find four loci, in/near CLASP1, LHX1, SNTA1, and CNTNAP2, that are associated with circulating lipid levels through interaction with physical activity; higher levels of physical activity enhance the HDL cholesterol-increasing effects of the CLASP1, LHX1, and SNTA1 loci and attenuate the LDL cholesterol-increasing effect of the CNTNAP2 locus. The CLASP1, LHX1, and SNTA1 regions harbor genes linked to muscle function and lipid metabolism. Our results elucidate the role of physical activity interactions in the genetic contribution to blood lipid levels

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

Productivity of Malaria Vectors from Different Habitat Types in the Western Kenya Highlands

BACKGROUND: Mosquito Larval Source Management (LSM) could be a valuable additional tool for integrated malaria vector control especially in areas with focal transmission like the highlands of western Kenya if it were not for the need to target all potential habitats at frequent intervals. The ability to determine the productivity of malaria vectors from identified habitats might be used to target LSM only at productive ones. METHODS: Each aquatic habitat within three highland sites in western Kenya was classified as natural swamp, cultivated swamp, river fringe, puddle, open drain or burrow pit. Three habitats of each type were selected in each site in order to study the weekly productivity of adult malaria vectors from February to May 2009 using a sweep-net and their habitat characteristics recorded. RESULTS: All surveyed habitat types produced adult malaria vectors. Mean adult productivity of Anopheles gambiae sensu lato in puddles (1.8/m(2)) was 11-900 times higher than in the other habitat types. However, puddles were the most unstable habitats having water at 43% of all sampling occasions and accounted for 5% of all habitats mapped in the study areas whereas open drains accounted for 72%. Densities of anopheline late instars larvae significantly increased with the presence of a biofilm but decreased with increasing surface area or when water was flowing. Taking stability and frequency of the habitat into account, puddles were still the most productive habitat types for malaria vectors but closely followed by open drains. CONCLUSION: Even though productivity of An. gambiae s.l. was greatest in small and unstable habitats, estimation of their overall productivity in an area needs to consider the more stable habitats over time and their surface extension. Therefore, targeting only the highly productive habitats is unlikely to provide sufficient reduction in malaria vector densities

Self-perceived stress reactivity is an indicator of psychosocial impairment at the workplace

BACKGROUND: Work related stress is associated with a range of debilitating health outcomes. However, no unanimously accepted assessment tool exists for the early identification of individuals suffering from chronic job stress. The psychological concept of self-perceived stress reactivity refers to the individual disposition of a person to answer stressors with immediate as well as long lasting stress reactions, and it could be a valid indicator of current as well as prospective adverse health outcomes. The aim of this study was to determine the extent to which perceived stress reactivity correlates with various parameters of psychosocial health, cardiovascular risk factors, and parameters of chronic stress and job stress in a sample of middle-aged industrial employees in a so-called "sandwich-position". METHODS: In this cross-sectional study, a total of 174 industrial employees were assessed for psychosocial and biological stress parameters. Differences between groups with high and low stress reactivity were analysed. Logistic regression models were applied to identify which parameters allow to predict perceived high versus low stress reactivity. RESULTS: In our sample various parameters of psychosocial stress like chronic stress and effort-reward imbalance were significantly increased in comparison to the normal population. Compared to employees with perceived low stress reactivity, those with perceived high stress reactivity showed poorer results in health-related complaints, depression, anxiety, sports behaviour, chronic stress, and effort-reward imbalance. The educational status of employees with perceived low stress reactivity is higher. Education, cardiovascular complaints, chronic stress, and effort-reward imbalance were moderate predictors for perceived stress reactivity. However, no relationship was found between stress reactivity and cardiovascular risk factors in our sample. CONCLUSIONS: Job stress is a major burden in a relevant subgroup of industrial employees in a middle management position. Self-perceived stress reactivity seems to be an appropriate concept to identify employees who experience psychosocial stress and associated psychological problems at the workplace