403 research outputs found

    Formaldehyde Exposure and Asthma in Children: A Systematic Review

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    Obj e c t i v e: Despite multiple published studies regarding the association between formaldehyde exposure and childhood asthma, a consistent association has not been identified. Here we report the results of a systematic review of published literature in order to provide a more comprehensive picture of this relationship. Data s o u r c e s: After a comprehensive literature search, we identified seven peer-reviewed studies providing quantitative results regarding the association between formaldehyde exposure and asthma in children. Studies were heterogeneous with respect to the definition of asthma (e.g., self-report, physician diagnosis). Most of the studies were cross-sectional

    Childhood Incident Asthma and Traffic-Related Air Pollution at Home and School

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    Background: Traffic-related air pollution has been associated with adverse cardiorespiratory effects, including increased asthma prevalence. However, there has been little study of effects of traffic exposure at school on new-onset asthma. Objectives: We evaluated the relationship of new-onset asthma with traffic-related pollution near homes and schools. Methods: Parent-reported physician diagnosis of new-onset asthma (n = 120) was identified during 3 years of follow-up of a cohort of 2,497 kindergarten and first-grade children who were asthma- and wheezing-free at study entry into the Southern California Children's Health Study. We assessed traffic-related pollution exposure based on a line source dispersion model of traffic volume, distance from home and school, and local meteorology. Regional ambient ozone, nitrogen dioxide (NO2), and particulate matter were measured continuously at one central site monitor in each of 13 study communities. Hazard ratios (HRs) for new-onset asthma were scaled to the range of ambient central site pollutants and to the residential interquartile range for each traffic exposure metric. Results: Asthma risk increased with modeled traffic-related pollution exposure from roadways near homes [HR 1.51; 95% confidence interval (CI), 1.25-1.82] and near schools (HR 1.45; 95% CI, 1.06-1.98). Ambient NO2 measured at a central site in each community was also associated with increased risk (HR 2.18; 95% CI, 1.18-4.01). In models with both NO2 and modeled traffic exposures, there were independent associations of asthma with traffic-related pollution at school and home, whereas the estimate for NO2 was attenuated (HR 1.37; 95% CI, 0.69-2.71). Conclusions: Traffic-related pollution exposure at school and homes may both contribute to the development of asthma. Editor's SummaryTraffic-related air pollution has been associated with adverse cardiorespiratory effects, including increased asthma prevalence. McConnell et al. (p. 1021) evaluated the relationship of new-onset asthma with traffic-related pollution near homes and schools. Parent-reported physician diagnosis of new-onset asthma was identified during 3 years of follow-up of a cohort of kindergarten and first-grade children who were asthma- and wheezing-free at study entry into the Southern California Children's Health Study. Traffic-related pollution exposure was assessed based on a line source dispersion model of traffic volume, distance from home and school, and local meteorology. Regional ambient ozone, nitrogen dioxide (NO2), and particulate matter were measured continuously at one central site monitor in each of 13 study communities. The authors report an increase in asthma risk with modeled traffic-related pollution exposure from roadways near homes and schools. Ambient NO2 was also associated with increased risk. Models that included both NO2 and modeled traffic exposures suggested independent associations of asthma with traffic-related pollution at school and at home, whereas the estimate for NO2 was attenuated. The authors conclude that traffic-related pollution exposure at school and home may both contribute to the development of asthma

    Organizational Support and Contract Fulfillment as Moderators of the Relationship Between Preferred Work Status and Performance

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    Purpose The purpose of this study was to examine organizational context variables as moderators of the relationship between preferred work status and job performance. The moderators were perceived organizational support (POS) and psychological contract fulfillment. Design/Methodology/Approach Survey data was collected from 164 participants working in a health and fitness organization. These participants ranged in age from 18 to 79 years old (M = 40, SD = 12.5) and held various positions including middle managers, clerical workers, maintenance workers, and sports trainers. Findings The relationship between preferred work status and extra-role performance was negative when POS was higher but not when POS was lower. Also, the relationship between preferred work status and extra-role performance was positive when contract fulfillment was lower but not when it was higher. No moderating effects were found when examining in-role performance. Implications Given the large and growing use of part-time workers it is important to understand differences across various subgroups of them in order to better inform human resource policies and practices. Specifically, the results highlight a key role for the management of reciprocity perceptions. Originality/Value The literature on part-time workers suggests there are important differences between employees who work part-time because they prefer it and those who work part-time but prefer to work full-time. Research regarding the relationship between preferred work status and performance has produced mixed results. This study helps reconcile conflicting results regarding the relationship between preferred work status and performance by examining the moderating effects of theoretically relevant variables

    Quality of care for older adults with chronic obstructive pulmonary disease and asthma based on comparisons to practice guidelines and smoking status

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to describe the prevalence of respiratory diseases in older adults and compare the demographic, health and smoking characteristics of those with and without these diseases. Furthermore, we evaluate the association between smoking status and patterns in health care and how concordant this care is with guidelines.</p> <p>Methods</p> <p>Using a nationally representative sample of 29,902 older adults who participated in the Medicare Current Beneficiary Survey (1992–2002), we compared guideline recommendations on the treatment and prevention of chronic obstructive pulmonary disease and asthma with survey utilization data, including the use of bronchodilators, spirometry and influenza vaccine.</p> <p>Results</p> <p>26% to 30% of older adults were diagnosed with or self-reported chronic respiratory diseases; however 69% received no pharmacological treatment and 30% of patients reporting use of pharmacological treatments did not receive short-acting bronchodilator inhalers. Current smokers appeared to receive significantly less care for respiratory diseases than non-smokers or former smokers.</p> <p>Conclusion</p> <p>Disparities between recommended and actual care for older adults with chronic lung disease require further research. The needs of older adults with co-morbidities and nicotine addiction deserve special attention in care as well as guideline development and implementation.</p

    Publication trends in the medical informatics literature: 20 years of "Medical Informatics" in MeSH

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study is to identify publication output, and research areas, as well as descriptively and quantitatively characterize the field of medical informatics through publication trend analysis over a twenty year period (1987–2006).</p> <p>Methods</p> <p>A bibliometric analysis of medical informatics citations indexed in Medline was performed using publication trends, journal frequency, impact factors, MeSH term frequencies and characteristics of citations.</p> <p>Results</p> <p>There were 77,023 medical informatics articles published during this 20 year period in 4,644 unique journals. The average annual article publication growth rate was 12%. The 50 identified medical informatics MeSH terms are rarely assigned together to the same document and are almost exclusively paired with a non-medical informatics MeSH term, suggesting a strong interdisciplinary trend. Trends in citations, journals, and MeSH categories of medical informatics output for the 20-year period are summarized. Average impact factor scores and weighted average impact factor scores increased over the 20-year period with two notable growth periods.</p> <p>Conclusion</p> <p>There is a steadily growing presence and increasing visibility of medical informatics literature over the years. Patterns in research output that seem to characterize the historic trends and current components of the field of medical informatics suggest it may be a maturing discipline, and highlight specific journals in which the medical informatics literature appears most frequently, including general medical journals as well as informatics-specific journals.</p

    Understanding the decomposition reaction mechanism of chrysanthemic acid: a computational study

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    <p>Abstract</p> <p>Background</p> <p>Chrysanthemic acid (<b>CHA</b>) is a major product from the photodecomposition of pyrethrin which is an important class of pesticide compounds.</p> <p>In the following paper, Hybrid density functional theory (DFT) calculations of the potential energy surface (PES) for three possible channels decomposition of chrysanthemic acid <b>(</b>cis-trans isomerization, rearrangement and fragmentation) have been carried at the B3LYP/6-311+G** level of theory. DFT was employed to optimize the geometry parameters of the reactants, transition states, intermediates and products based on detailed potential energy surfaces (PES).</p> <p>Results</p> <p>Our results suggest that all three pathways of <b>CHA </b>are endothermic. DFT calculations revealed that the activation barriers for cis-trans isomerization are low, leading to a thermodynamically favorable process than other two pathways. We also investigated the solvent effect on the PES using the polarizable continuum model (PCM). In addition, time-dependent density functional theory (TDDFT) calculations showed that these reactions occur in the ground state rather than in an excited state.</p> <p>Conclusion</p> <p>The rearrangement process seems to be more favorable than the decomposition of <b>CHA </b>to carbene formation. The solvent effect calculations indicated no changes in the shape of the PES with three continua (water, ethanol and cyclohexane), although the solvents tend to stabilize all of the species.</p

    Promoting mental health in small-medium enterprises: An evaluation of the "Business in Mind" program

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    <p>Abstract</p> <p>Background</p> <p>Workplace mental health promotion (WMHP) aims to prevent and effectively manage the social and economic costs of common mental illnesses such as depression. The mental health of managers and employees within small-medium enterprises (SMEs) is a neglected sector in occupational health research and practice, despite the fact that this sector is the most common work setting in most economies. The availability and propensity of SME staff to attend face-to-face training/therapy or workshop style interventions often seen in corporate or public sector work settings is a widely recognised problem. The 'Business in Mind' program employs a DVD mode of delivery that is convenient for SME managers, particularly those operating in regional and remote areas where internet delivery may not be optimal. The objective of the intervention program is to improve the mental health of SME managers, and examine whether employees of managers' whose mental health improves, report positive change in their psychosocial work environment. The mechanisms via which we aim to improve managers' mental health are through the development of their psychological capital (a higher order construct comprised of hope, self efficacy, resilience and optimism) and their skills and capacities for coping with work stress.</p> <p>Methods/Design</p> <p>The effectiveness of two versions of the program (self administered and telephone facilitated) will be assessed using a randomised trial with an active control condition (psychoeducation only). We aim to recruit a minimum of 249 managers and a sample of their employees. This design allows for 83 managers per group, as power analyses showed that this number would allow for attrition of 20% and still enable detection of an effect size of 0.5. The intervention will be implemented over a three month period and postal surveys will assess managers and employees in each group at baseline, intervention completion, and at 6 month follow up. The intervention groups (managers only) will also be assessed at 12 and 24 month follow-up to examine maintenance of effects. Primary outcomes are managers' levels of psychological capital (hope, resilience, self-efficacy and optimism), coping strategies, anxiety and depression symptoms, self-reported health, job satisfaction and job tension. Secondary outcomes are participating managers subordinates' perceptions of manager support, relational justice, emotional climate and job tension. In order to provide an economic evaluation of the intervention, both employees and manager rates of absenteeism and presenteeism will also be assessed.</p> <p>Discussion</p> <p>The intervention being trialled is expected to improve both primary and secondary outcomes. If proven efficacious, the intervention could be disseminated to reach a much larger proportion of the business community.</p> <p>Trial registration</p> <p>Current controlled trials ISRCTN 62853520</p
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