185 research outputs found
Bromide and other ions in the snow, firn air, and atmospheric boundary layer at Summit during GSHOX
Measurements of gas phase soluble bromide in the boundary layer and in firn air, and Br− in aerosol and snow, were made at Summit, Greenland (72.5° N, 38.4° W, 3200 m a.s.l.) as part of a larger investigation into the influence of Br chemistry on HOx cycling. The soluble bromide measurements confirm that photochemical activation of Br− in the snow causes release of active Br to the overlying air despite trace concentrations of Br− in the snow (means 15 and 8 nmol Br− kg−1 of snow in 2007 and 2008, respectively). Mixing ratios of soluble bromide above the snow were also found to be very small (mean \u3c1 ppt both years, with maxima of 3 and 4 ppt in 2007 and 2008, respectively), but these levels clearly oxidize and deposit long-lived gaseous elemental mercury and may perturb HOx partitioning. Concentrations of Br− in surface snow tended to increase/decrease in parallel with the specific activities of the aerosol-associated radionuclides 7Be and 210Pb. Earlier work has shown that ventilation of the boundary layer causes simultaneous increases in 7Be and 210Pb at Summit, suggesting there is a pool of Br in the free troposphere above Summit in summer time. Speciation and the source of this free tropospheric Br− are not well constrained, but we suggest it may be linked to extensive regions of active Br chemistry in the Arctic basin which are known to cause ozone and mercury depletion events shortly after polar sunrise. If this hypothesis is correct, it implies persistence of the free troposphere Br− for several months after peak Br activation in March/April. Alternatively, there may be a ubiquitous pool of Br− in the free troposphere, sustained by currently unknown sources and processes
Evaluation and management implications of uncertainty in a multispecies size-structured model of population and community responses to fishing
1. Implementation of an ecosystem approach to fisheries requires advice on trade-offs among fished species and between fisheries yields and biodiversity or food web properties. However, the lack of explicit representation, analysis and consideration of uncertainty in most multispecies models has limited their application in analyses that could support management advice. 2. We assessed the consequences of parameter uncertainty by developing 78 125 multispecies size-structured fish community models, with all combinations of parameters drawn from ranges that spanned parameter values estimated from data and literature. This unfiltered ensemble was reduced to 188 plausible models, the filtered ensemble (FE), by screening outputs against fish abundance data and ecological principles such as requiring species' persistence. 3. Effects of parameter uncertainty on estimates of single-species management reference points for fishing mortality (FMSY, fishing mortality rate providing MSY, the maximum sustainable yield) and biomass (BMSY, biomass at MSY) were evaluated by calculating probability distributions of estimated reference points with the FE. There was a 50% probability that multispecies FMSY could be estimated to within ±25% of its actual value, and a 50% probability that BMSY could be estimated to within ±40% of its actual value. 4. Signal-to-noise ratio was assessed for four community indicators when mortality rates were reduced from current rates to FMSY. The slope of the community size spectrum showed the greatest signal-to-noise ratio, indicating that it would be the most responsive indicator to the change in fishing mortality F. Further, the power of an ongoing international monitoring survey to detect predicted responses of size spectrum slope was higher than for other size-based metrics. 5. Synthesis and applications: Application of the ensemble model approach allows explicit representation of parameter uncertainty and supports advice and management by (i) providing uncertainty intervals for management reference points, (ii) estimating working values of reference points that achieve a defined reduction in risk of not breaching the true reference point, (iii) estimating the responsiveness of population, community, food web and biodiversity indicators to changes in F, (iv) assessing the performance of indicators and monitoring programmes and (v) identifying priorities for data collection and changes to model structure to reduce uncertainty
Incorporating health literacy in education for socially disadvantaged adults: an Australian feasibility study.
BACKGROUND: Adult education institutions have been identified as potential settings to improve health literacy and address the health inequalities that stem from limited health literacy. However, few health literacy interventions have been tested in this setting. METHODS: Feasibility study for an RCT of the UK Skilled for Health Program adapted for implementation in Australian adult education settings. Implementation at two sites with mixed methods evaluation to examine feasibility, test for change in participants' health literacy and pilot test health literacy measures. RESULTS: Twenty-two socially disadvantaged adults with low literacy participated in the program and received 80-90 hours of health literacy instruction. The program received institutional support from Australia's largest provider of vocational education and training and was feasible to implement (100 % participation; >90 % completion; high teacher satisfaction). Quantitative results showed improvements in participants' health literacy skills and confidence, with no change on a generic measure of health literacy. Qualitative analysis identified positive student and teacher engagement with course content and self-reported improvements in health knowledge, attitudes, and communication with healthcare professionals. CONCLUSIONS: Positive feasibility results support a larger RCT of the health literacy program. However, there is a need to identify better, multi-dimensional measures of health literacy in order to be able to quantify change in a larger trial. This feasibility study represents the first step in providing the high quality evidence needed to understand the way in which health literacy can be improved and health inequalities reduced through Australian adult education programs
Learners' experience and perceived impact of a health literacy program in adult basic education: a qualitative study.
Objectives and importance of the study: Adult literacy programs aim to empower learners to participate more effectively in everyday life. This includes programs with health content embedded in curricula to target health literacy. Adult learners who attend these programs represent a heterogeneous population, but include a high proportion of hard-to-reach or socially disadvantaged groups in terms of age, ethnicity, educational background, language and prevalence of learning disabilities. In 2014, we conducted a cluster-randomised controlled trial of a health literacy program in adult basic education classes across New South Wales, Australia. This paper reports findings from a qualitative study exploring learners' experience of the course and its perceived impact on their lives, as well as their understanding and confidence about health. STUDY TYPE:Qualitative interview study. METHOD:We conducted semistructured interviews as part of the evaluation of the 18-week health literacy program, with participants purposively recruited from six health literacy classes (n = 22). Researchers trained in qualitative methods interviewed adult learners either face to face or over the phone using a topic guide. Data was analysed using the Framework method, a matrix-based approach to thematic analysis. RESULTS:The majority of interviewees were female, lived in metropolitan areas and were from non-English-speaking backgrounds. Most had existing self-reported health problems and inadequate functional health literacy. Most participants described positive impacts of the health literacy course on their language, literacy and numeracy skills, functional health literacy skills, and health knowledge. They also reported being able to translate this into health actions including interacting with providers, accessing and using healthcare, and managing health and illness (e.g. making healthier food choices). Learners also described positive social outcomes of the course, including feelings of connectedness and interpersonal trust within a new network of learners, and reported sharing new knowledge with others in their communities. CONCLUSIONS:The findings add value to existing limited evidence that has demonstrated the untapped potential of adult basic education to develop health literacy skills among socially disadvantaged groups. Learners valued the opportunity to share experiences in structured group learning, and reported confidence to transfer new knowledge into their home and wider social network
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Effect of pressure treatment with coal-tar creosote on the strength of Douglas-fir structural timbers
Biochemistry Instructors’ Views toward Developing and Assessing Visual Literacy in Their Courses
Biochemistry instructors are inundated with various representations from which to choose to depict biochemical phenomena. Because of the immense amount of visual know-how needed to be an expert biochemist in the 21st century, there have been calls for instructors to develop biochemistry students’ visual literacy. However, visual literacy has multiple aspects, and determining which area to develop can be quite daunting. Therefore, the goals of this study were to determine what visual literacy skills biochemistry instructors deem to be most important and how instructors develop and assess visual literacy skills in their biochemistry courses. In order to address these goals, a needs assessment was administered to a national sample of biochemistry faculty at four-year colleges and universities. Based on the results of the survey, a cluster analysis was conducted to group instructors into categories based on how they intended to develop visual literacy in their courses. A misalignment was found between the visual literacy skills that were most important and how instructors developed visual literacy. In addition, the majority of instructors assumed these skills on assessments rather than explicitly testing them. Implications focus on the need for better measures to assess visual literacy skills directly
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Bayesian approach to determining penetrance of pathogenic SDH variants.
BACKGROUND: Until recently, determining penetrance required large observational cohort studies. Data from the Exome Aggregate Consortium (ExAC) allows a Bayesian approach to calculate penetrance, in that population frequencies of pathogenic germline variants should be inversely proportional to their penetrance for disease. We tested this hypothesis using data from two cohorts for succinate dehydrogenase subunits A, B and C (SDHA-C) genetic variants associated with hereditary pheochromocytoma/paraganglioma (PC/PGL). METHODS: Two cohorts were 575 unrelated Australian subjects and 1240 unrelated UK subjects, respectively, with PC/PGL in whom genetic testing had been performed. Penetrance of pathogenic SDHA-C variants was calculated by comparing allelic frequencies in cases versus controls from ExAC (removing those variants contributed by The Cancer Genome Atlas). RESULTS: Pathogenic SDHA-C variants were identified in 106 subjects (18.4%) in cohort 1 and 317 subjects (25.6%) in cohort 2. Of 94 different pathogenic variants from both cohorts (seven in SDHA, 75 in SDHB and 12 in SDHC), 13 are reported in ExAC (two in SDHA, nine in SDHB and two in SDHC) accounting for 21% of subjects with SDHA-C variants. Combining data from both cohorts, estimated lifetime disease penetrance was 22.0% (95% CI 15.2% to 30.9%) for SDHB variants, 8.3% (95% CI 3.5% to 18.5%) for SDHC variants and 1.7% (95% CI 0.8% to 3.8%) for SDHA variants. CONCLUSION: Pathogenic variants in SDHB are more penetrant than those in SDHC and SDHA. Our findings have important implications for counselling and surveillance of subjects carrying these pathogenic variants
Bayesian approach to determining penetrance of pathogenic SDH variants.
BACKGROUND: Until recently, determining penetrance required large observational cohort studies. Data from the Exome Aggregate Consortium (ExAC) allows a Bayesian approach to calculate penetrance, in that population frequencies of pathogenic germline variants should be inversely proportional to their penetrance for disease. We tested this hypothesis using data from two cohorts for succinate dehydrogenase subunits A, B and C (SDHA-C) genetic variants associated with hereditary pheochromocytoma/paraganglioma (PC/PGL). METHODS: Two cohorts were 575 unrelated Australian subjects and 1240 unrelated UK subjects, respectively, with PC/PGL in whom genetic testing had been performed. Penetrance of pathogenic SDHA-C variants was calculated by comparing allelic frequencies in cases versus controls from ExAC (removing those variants contributed by The Cancer Genome Atlas). RESULTS: Pathogenic SDHA-C variants were identified in 106 subjects (18.4%) in cohort 1 and 317 subjects (25.6%) in cohort 2. Of 94 different pathogenic variants from both cohorts (seven in SDHA, 75 in SDHB and 12 in SDHC), 13 are reported in ExAC (two in SDHA, nine in SDHB and two in SDHC) accounting for 21% of subjects with SDHA-C variants. Combining data from both cohorts, estimated lifetime disease penetrance was 22.0% (95% CI 15.2% to 30.9%) for SDHB variants, 8.3% (95% CI 3.5% to 18.5%) for SDHC variants and 1.7% (95% CI 0.8% to 3.8%) for SDHA variants. CONCLUSION: Pathogenic variants in SDHB are more penetrant than those in SDHC and SDHA. Our findings have important implications for counselling and surveillance of subjects carrying these pathogenic variants
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