742 research outputs found

    Charge Symmetry Breaking in 500 MeV Nucleon-Trinucleon Scattering

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    Elastic nucleon scattering from the 3He and 3H mirror nuclei is examined as a test of charge symmetry violation. The differential cross-sections are calculated at 500 MeV using a microsopic, momentum-space optical potential including the full coupling of two spin 1/2 particles and an exact treatment of the Coulomb force. The charge-symmetry-breaking effects investigated arise from a violation within the nuclear structure, from the p-nucleus Coulomb force, and from the mass-differences of the charge symmetric states. Measurements likely to reveal reliable information are noted.Comment: 5 page

    Reductions in cardiovascular, cerebrovascular, and respiratory mortality following the national Irish smoking ban: Interrupted time-series analysis

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    Copyright @ 2013 Stallings-Smith et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Previous studies have shown decreases in cardiovascular mortality following the implementation of comprehensive smoking bans. It is not known whether cerebrovascular or respiratory mortality decreases post-ban. On March 29, 2004, the Republic of Ireland became the first country in the world to implement a national workplace smoking ban. The aim of this study was to assess the effect of this policy on all-cause and cause-specific, non-trauma mortality. Methods: A time-series epidemiologic assessment was conducted, utilizing Poisson regression to examine weekly age and gender-standardized rates for 215,878 non-trauma deaths in the Irish population, ages ≥35 years. The study period was from January 1, 2000, to December 31, 2007, with a post-ban follow-up of 3.75 years. All models were adjusted for time trend, season, influenza, and smoking prevalence. Results: Following ban implementation, an immediate 13% decrease in all-cause mortality (RR: 0.87; 95% CI: 0.76-0.99), a 26% reduction in ischemic heart disease (IHD) (RR: 0.74; 95% CI: 0.63-0.88), a 32% reduction in stroke (RR: 0.68; 95% CI: 0.54-0.85), and a 38% reduction in chronic obstructive pulmonary disease (COPD) (RR: 0.62; 95% CI: 0.46-0.83) mortality was observed. Post-ban reductions in IHD, stroke, and COPD mortalities were seen in ages ≥65 years, but not in ages 35-64 years. COPD mortality reductions were found only in females (RR: 0.47; 95% CI: 0.32-0.70). Post-ban annual trend reductions were not detected for any smoking-related causes of death. Unadjusted estimates indicate that 3,726 (95% CI: 2,305-4,629) smoking-related deaths were likely prevented post-ban. Mortality decreases were primarily due to reductions in passive smoking. Conclusions: The national Irish smoking ban was associated with immediate reductions in early mortality. Importantly, post-ban risk differences did not change with a longer follow-up period. This study corroborates previous evidence for cardiovascular causes, and is the first to demonstrate reductions in cerebrovascular and respiratory causes

    Viewing Nature Scenes Positively Affects Recovery of Autonomic Function Following Acute-Mental Stress

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    A randomized crossover study explored whether viewing different scenes prior to a stressor altered autonomic function during the recovery from the stressor. The two scenes were (a) nature (composed of trees, grass, fields) or (b) built (composed of man-made, urban scenes lacking natural characteristics) environments. Autonomic function was assessed using noninvasive techniques of heart rate variability; in particular, time domain analyses evaluated parasympathetic activity, using root-mean-square of successive differences (RMSSD). During stress, secondary cardiovascular markers (heart rate, systolic and diastolic blood pressure) showed significant increases from baseline which did not differ between the two viewing conditions. Parasympathetic activity, however, was significantly higher in recovery following the stressor in the viewing scenes of nature condition compared to viewing scenes depicting built environments (RMSSD; 50.0 ± 31.3 vs 34.8 ± 14.8 ms). Thus, viewing nature scenes prior to a stressor alters autonomic activity in the recovery period. The secondary aim was to examine autonomic function during viewing of the two scenes. Standard deviation of R-R intervals (SDRR), as change from baseline, during the first 5 min of viewing nature scenes was greater than during built scenes. Overall, this suggests that nature can elicit improvements in the recovery process following a stressor. © 2013 American Chemical Society

    Pion interaction with the trinucleon up to the eta production threshold

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    Pion elastic, charge exchange scattering and induced eta production on the trinucleon systems are investigated in a coupled-channels approach in momentum space with Fadeev wave functions. The channel πNηN\pi N \rightarrow \eta N is included using an isobar model with S-, P-, and D-wave resonances. While the coherent reactions like 3^3He(π,π)3\pi,\pi)^3He can be reasonably well reproduced up to TπT_{\pi}=500 MeV, large discrepancies appear for the incoherent processes, 3^3He(π,π0)3\pi^-,\pi^0)^3H and 3^3He(π,η)3\pi^-,\eta)^3H at backward angles and energies above Δ\Delta-resonance. In the forward direction the (π,η)(\pi,\eta) calculations underestimate the experimental measurements very close to threshold but agreement with the data improves with increasing pion energy. Predictions are made for the asymmetries of the various reactions on polarized 3^3He.Comment: 40 pages, 12 figures (available from the authors), Mainz preprint MKPH-T-92-1

    Walks4work: Rationale and study design to investigate walking at lunchtime in the workplace setting

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    Background: Following recruitment of a private sector company, an 8week lunchtime walking intervention was implemented to examine the effect of the intervention on modifiable cardiovascular disease risk factors, and further to see if walking environment had any further effect on the cardiovascular disease risk factors. Methods. For phase 1 of the study participants were divided into three groups, two lunchtime walking intervention groups to walk around either an urban or natural environment twice a week during their lunch break over an 8week period. The third group was a waiting-list control who would be invited to join the walking groups after phase 1. In phase 2 all participants were encouraged to walk during their lunch break on self-selecting routes. Health checks were completed at baseline, end of phase 1 and end of phase 2 in order to measure the impact of the intervention on cardiovascular disease risk. The primary outcome variables of heart rate and heart rate variability were measured to assess autonomic function associated with cardiovascular disease. Secondary outcome variables (Body mass index, blood pressure, fitness, autonomic response to a stressor) related to cardiovascular disease were also measured. The efficacy of the intervention in increasing physical activity was objectively monitored throughout the 8-weeks using an accelerometer device. Discussion. The results of this study will help in developing interventions with low researcher input with high participant output that may be implemented in the workplace. If effective, this study will highlight the contribution that natural environments can make in the reduction of modifiable cardiovascular disease risk factors within the workplace. © 2012 Brown et al.; licensee BioMed Central Ltd

    Neutron structure function and inclusive DIS from H-3 and He-3 at large Bjorken-x

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    A detailed study of inclusive deep inelastic scattering (DIS) from mirror A = 3 nuclei at large values of the Bjorken variable x is presented. The main purpose is to estimate the theoretical uncertainties on the extraction of the neutron DIS structure function from such nuclear measurements. On one hand, within models in which no modification of the bound nucleon structure functions is taken into account, we have investigated the possible uncertainties arising from: i) charge symmetry breaking terms in the nucleon-nucleon interaction, ii) finite Q**2 effects neglected in the Bjorken limit, iii) the role of different prescriptions for the nucleon Spectral Function normalization providing baryon number conservation, and iv) the differences between the virtual nucleon and light cone formalisms. Although these effects have been not yet considered in existing analyses, our conclusion is that all these effects cancel at the level of ~ 1% for x < 0.75 in overall agreement with previous findings. On the other hand we have considered several models in which the modification of the bound nucleon structure functions is accounted for to describe the EMC effect in DIS scattering from nuclei. It turns out that within these models the cancellation of nuclear effects is expected to occur only at a level of ~ 3%, leading to an accuracy of ~ 12 % in the extraction of the neutron to proton structure function ratio at x ~ 0.7 -0.8$. Another consequence of considering a broad range of models of the EMC effect is that the previously suggested iteration procedure does not improve the accuracy of the extraction of the neutron to proton structure function ratio.Comment: revised version to appear in Phys. Rev. C; main modifications in Section 4; no change in the conclusion

    Market Work, Home Production, Consumer Demand and Unemployment among the Unskilled

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    We develop a general equilibrium model in which longer working time and higher labor force participation lead to a fall in unemployment. Longer working hours and higher labor force participation have two direct effects: People have higher incomes and less (leisure) time. This has implications for the composition of consumer demand, since people spend less time on home production. Instead, they outsource more domestic tasks to the market. Consumer demand shifts toward unskill-intensive goods. The relative demand for unskilled labor rises and unemployment falls. We provide empirical evidence for our theoretical predictions in several ways: We study the link between labor market participation, home production and the demand for household and similar services using the German time use survey conducted in 1991/92. In addition, we use panel data for 23 OECD countries between 1980 and 2003 to directly examine the link between labor force participation and the unemployment rate. The empirical results corroborate the predictions from the theoretical model

    Intergenerational mobility of housework time in the United Kingdom

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    This paper analyzes the relationship between parents’ time devoted to housework and the time devoted to housework by their children. Using data from the Multinational Time Use Study for the UK, we find positive intergenerational correlations in housework for both parents, indicating that the more time parents devote to housework, the more time their children will devote to housework. Using data from the British Household Panel Survey, we find that a higher father–mother housework ratio is positively related to a higher child–mother housework ratio, even after allowing for individual fixed-effects. In order to address the potential exacerbation of errors-in-variables arising from the fixed-effects specification, we instrument the father–mother ratio of housework using father’s and mother’s lagged weekly working hours. The Instrumental-Variable estimates fully support the fixed-effects estimates, and suggest that the latter should be regarded as a lower bound. We also present evidence of the link between housework during adolescence and duringadulthood, which may indicate that housework time during adulthood depends on the housework time during childhood, which may also be affected by parents’ housework time. Our results contribute to the field of the intergenerational mobility of behaviors

    Assessing Client Progress Session by Session in the Treatment of Social Anxiety Disorder: The Social Anxiety Session Change Index

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    Frequent assessment during therapy can improve treatments and provide accountability. However, clinicians often do not monitor progress because of the time it takes to administer and score assessments. In response, the Social Anxiety Session Change Index (SASCI) was developed. The SASCI is a short, easily administered rating of subjective improvement that asks clients with social anxiety disorder how much they have changed since the beginning of therapy. Change on the SASCI was related to change in fear of negative evaluation, a core aspect of social anxiety, and to clinician-rated improvement, but not to ratings of anxiety sensitivity or depression. Because it is brief and easily interpretable, the SASCI can be used in a variety of clinical settings to monitor change across therapy. The SASCI is presented along with examples of how the information gathered from frequent administration can inform clinical practice
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