25,974 research outputs found
Mission impossible? Identity based incompatibilities amongst academic job roles relate to wellbeing and turnover.
Academic staff experience high levels of work-related stress and poor mental health. As a result, many institutions face high staff turnover. These outcomes may be driven by the complexity and, at times, apparently oppositional objectives academics need to meet around research and teaching. These factors may present both practical and social identity-based incompatibilities. The current study tested the role of these incompatibilities upon mental well-being and turnover. A sample of 141 UK resident academics completed scales measuring levels of social identification with being an academic, an educator and a researcher, identity based and practical incompatibility, mental health, experience of the workplace and turnover intention. No direct links were found between practical incompatibility and outcomes. However, higher identity incompatibility was related to poorer mental health. Identity incompatibility was also related to turnover intention, mediated by both mental health and workplace experience. Contrary to predictions, these effects were not moderated by identity difference or identity strength. The current findings present evidence that role-based incompatibilities have both practical and identity-based foundations and highlight important caveats to the benefits of multiple identities on well-being observed in other domains. The findings also suggest practical steps through which complex occupational roles can be best structured to improve mental health and reduce turnover
Comparison of Allen Carr's Easyway programme with a specialist behavioural and pharmacological smoking cessation support service: a randomized controlled trial.
BACKGROUND AND AIMS: A combination of behavioural and pharmacological support is judged to be the optimal approach for assisting smoking cessation. Allen Carr's Easyway (ACE) is a single-session pharmacotherapy-free programme that has been in operation internationally for 38 years. We compared the effectiveness of ACE with specialist behavioural and pharmacological support delivered to the national standard in England. DESIGN: A two-arm, parallel-group, single-blind, randomized controlled trial. SETTING: London, UK, between February 2017 and May 2018. PARTICIPANTS: A total of 620 participants (310 in ACE and 310 in the combined behavioural and pharmacological support condition) were included in the analysis. Adult (≥ 18 years) smokers wanting to quit were randomized in a 1 : 1 ratio. Mean age for the total sample was 40.8 years, with 53.4% being male. Participant baseline characteristics (ethnicity, educational level, number of previous quit attempts, nicotine dependence) were evenly balanced between treatment groups. INTERVENTION AND COMPARATOR: The intervention was the ACE method of stopping smoking. This centres on a 4.5-6-hour session of group-based support, alongside subsequent text messages and top-up sessions if needed. It aims to make it easy to stop smoking by convincing smokers that smoking provides no benefits for them. The comparator was a specialist stop smoking service (SSS) providing behavioural and pharmacological support in accordance with national standards. MEASUREMENTS: The primary outcome was self-reported continuous abstinence for 26 weeks from the quit/quit re-set date verified by exhaled breath carbon monoxide measurement < 10 parts per million (p.p.m.). Primary analysis was by intention to treat. Secondary outcomes were: use of pharmacotherapy, adverse events and continuous abstinence up to 4 and 12 weeks. FINDINGS: A total of 468 participants attended treatment (255 ACE versus 213 SSS, P < 0.05). Of those who did attend treatment, 100 completed 6-month measures (23.7% ACE versus 20.7% SSS). Continuous abstinence to 26 weeks was 19.4% (60 of 310) in the ACE intervention and 14.8% (46 of 310) in the SSS intervention [risk difference for ACE versus SSS 4.5% (95% confidence interval (CI) = -1.4 to 10.4%, odds ratio (OR) = 1.38)]. The Bayes factor for superiority of the ACE condition was 1.24. CONCLUSION: There was no clear evidence of a difference in the efficacies of the Allen Carr's Easyway (ACE) and specialist smoking cessation support involving behavioural support and pharmacotherapy
Exoplanet Transit Variability: Bow Shocks and Winds Around HD 189733b
By analogy with the solar system, it is believed that stellar winds will form
bow shocks around exoplanets. For hot Jupiters the bow shock will not form
directly between the planet and the star, causing an asymmetric distribution of
mass around the exoplanet and hence an asymmetric transit. As the planet orbits
thorough varying wind conditions, the strength and geometry of its bow shock
will change, thus producing transits of varying shape. We model this process
using magnetic maps of HD 189733 taken one year apart, coupled with a 3D
stellar wind model, to determine the local stellar wind conditions throughout
the orbital path of the planet. We predict the time-varying geometry and
density of the bow shock that forms around the magnetosphere of the planet and
simulate transit light curves. Depending on the nature of the stellar magnetic
field, and hence its wind, we find that both the transit duration and ingress
time can vary when compared to optical light curves. We conclude that
consecutive near-UV transit light curves may vary significantly and can
therefore provide an insight into the structure and evolution of the stellar
wind.Comment: 9 Pages, 7 figures. Accepted for publication in Monthly Notices of
The Royal Astronomical Societ
Spectropolarimetry of the H-alpha line in Herbig Ae/Be stars
Using the HiVIS spectropolarimeter built for the Haleakala 3.7m AEOS
telescope, we have obtained a large number of high precision spectropolarimetrc
observations (284) of Herbig AeBe stars collected over 53 nights totaling more
than 300 hours of observing. Our sample of five HAeBe stars: AB Aurigae,
MWC480, MWC120, MWC158 and HD58647, all show systematic variations in the
linear polarization amplitude and direction as a function of time and
wavelength near the H-alpha line. In all our stars, the H-alpha line profiles
show evidence of an intervening disk or outflowing wind, evidenced by strong
emission with an absorptive component. The linear polarization varies by 0.2%
to 1.5% with the change typically centered in the absorptive part of the line
profile. These observations are inconsistent with a simple disk-scattering
model or a depolarization model which produce polarization changes centered on
the emmissive core. We speculate that polarized absorption via optical pumping
of the intervening gas may be the cause.Comment: Accepted for publication in ApJ Letter
The lead discrepancy in intrinsically s-process enriched post-AGB stars in the Magellanic Clouds
Context: Our understanding of the s-process nucleosynthesis in asymptotic
giant branch (AGB) stars is incomplete. AGB models predict, for example, large
overabundances of lead (Pb) compared to other s-process elements in metal-poor
low-mass AGB stars. This is indeed observed in some extrinsically enhanced
metal-poor stars, but not in all. An extensive study of intrinsically s-process
enriched objects is essential for improving our knowledge of the AGB third
dredge-up and associated s-process nucleosynthesis. Aims: We compare the
spectral abundance analysis of the SMC post-AGB star J004441.04-732136.4 with
state-of-the-art AGB model predictions with a main focus on Pb. The low S/N in
the Pb line region made the result of our previous study inconclusive. We
acquired additional data covering the region of the strongest Pb line. Methods:
By carefully complementing re-reduced previous data, with newly acquired UVES
optical spectra, we improve the S/N of the spectrum around the strongest Pb
line. Therefore, an upper limit for the Pb abundance is estimated from a merged
weighted mean spectrum using synthetic spectral modeling. We then compare the
abundance results from the combined spectra to predictions of tailored AGB
evolutionary models from two independent evolution codes. In addition, we
determine upper limits for Pb abundances for three previously studied LMC
post-AGB objects. Results: Although theoretical predictions for
J004441.04-732136.4 match the s-process distribution up to tungsten (W), the
predicted very high Pb abundance is clearly not detected. The three additional
LMC post-AGB stars show a similar lack of a very high Pb abundance. Conclusion:
From our study, we conclude that none of these low-mass, low-metallicity
post-AGB stars of the LMC and SMC are strong Pb producers. This conflicts with
current theoretical predictions.Comment: 4 pages, 3 figure
Do Employees From Less-Healthy Communities Use More Care and Cost More? Seeking to Establish a Business Case for Investment in Community Health.
INTRODUCTION: Few studies have examined the impact of community health on employers. We explored whether employed adults and their adult dependents living in less-healthy communities in the greater Philadelphia region used more care and incurred higher costs to employers than employees from healthier communities.
METHODS: We used a multi-employer database to identify adult employees and dependents with continuous employment and mapped them to 31 zip code regions. We calculated community health scores at the regional level, by using metrics similar to the Robert Wood Johnson Foundation (RWJF) County Health Rankings but with local data. We used descriptive analyses and multilevel linear modeling to explore relationships between community health and 3 outcome variables: emergency department (ED) use, hospital use, and paid claims. Business leaders reviewed findings and offered insights on preparedness to invest in community health improvement.
RESULTS: Poorer community health was associated with high use of ED services, after controlling for age and sex. After including a summary measure of racial composition at the zip code region level, the relationship between community health and ED use became nonsignificant. No significant relationships between community health and hospitalizations or paid claims were identified. Business leaders expressed interest in further understanding health needs of communities where their employees live.
CONCLUSION: The health of communities in which adult employees and dependents live was associated with ED use, but similar relationships were not seen for hospitalizations or paid claims. This finding suggests a need for more primary care access. Despite limited quantitative evidence, business leaders expressed interest in guidance on investing in community health improvement
Use of Desulfovibrio and Escherichia coli Pd-nanocatalysts in reduction of Cr(VI) and hydrogenolytic dehalogenation of polychlorinated biphenyls and used transformer oil
BACKGROUND Desulfovibrio spp. biofabricate metallic nanoparticles (e.g. ‘Bio-Pd’) which catalyse the reduction of Cr(VI) to Cr(III) and dehalogenate polychlorinated biphenyls (PCBs). Desulfovibrio spp. are anaerobic and produce H2S, a potent catalyst poison, whereas Escherichia coli can be pre-grown aerobically to high density, has well defined molecular tools, and also makes catalytically-active ‘Bio-Pd’. The first aim was to compare ‘Bio-Pd’ catalysts made by Desulfovibrio spp. and E. coli using suspended and immobilised catalysts. The second aim was to evaluate the potential for Bio-Pd-mediated dehalogenation of PCBs in used transformer oils, which preclude recovery and re-use.\ud
RESULTS Catalysis via Bio-PdD. desulfuricans and Bio-PdE. coli was compared at a mass loading of Pd:biomass of 1:3 via reduction of Cr(VI) in aqueous solution (immobilised catalyst) and hydrogenolytic release of Cl- from PCBs and used transformer oil (catalyst suspensions). In both cases Bio-PdD. desulfuricans outperformed Bio-Pd E. coli by ~3.5-fold, attributable to a ~3.5-fold difference in their Pd-nanoparticle surface areas determined by magnetic measurements (Bio-PdD. desulfuricans) and by chemisorption analysis (Bio-PdE. coli). Small Pd particles were confirmed on D. desulfuricans and fewer, larger ones on E. coli via electron microscopy. Bio-PdD. desulfuricans-mediated chloride release from used transformer oil (5.6 0.8 g mL-1 ) was comparable to that observed using several PCB reference materials. \ud
CONCLUSIONS At a loading of 1:3 Pd: biomass Bio-PdD. desulfuricans is 3.5-fold more active than Bio-PdE. coli, attributable to the relative catalyst surface areas reflected in the smaller nanoparticle sizes of the former. This study also shows the potential of Bio-PdD. desulfuricans to remediate used transformer oil
Near-bandgap wavelength-dependent studies of long-lived traveling coherent longitudinal acoustic phonon oscillations in GaSb/GaAs systems
We report first studies of long-lived oscillations in optical pump-probe
measurements on GaSb-GaAs heterostructures. The oscillations arise from a
photogenerated coherent longitudinal acoustic phonon wave, which travels from
the top surface of GaSb across the interface into the GaAs substrate, providing
information on the optical properties of the material as a function of
time/depth. Wavelength-dependent studies of the oscillations near the bandgap
of GaAs indicate strong correlations to the optical properties of GaAs.Comment: 11 pages, 4 figure
Osculating and neighbour-avoiding polygons on the square lattice
We study two simple modifications of self-avoiding polygons. Osculating
polygons are a super-set in which we allow the perimeter of the polygon to
touch at a vertex. Neighbour-avoiding polygons are only allowed to have nearest
neighbour vertices provided these are joined by the associated edge and thus
form a sub-set of self-avoiding polygons. We use the finite lattice method to
count the number of osculating polygons and neighbour-avoiding polygons on the
square lattice. We also calculate their radius of gyration and the first
area-weighted moment. Analysis of the series confirms exact predictions for the
critical exponents and the universality of various amplitude combinations. For
both cases we have found exact solutions for the number of convex and
almost-convex polygons.Comment: 14 pages, 5 figure
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