45 research outputs found

    Top-down constraints on atmospheric mercury emissions and implications for global biogeochemical cycling

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    We perform global-scale inverse modeling to constrain present-day atmospheric mercury emissions and relevant physiochemical parameters in the GEOS-Chem chemical transport model. We use Bayesian inversion methods combining simulations with GEOS-Chem and ground-based Hg[superscript 0] observations from regional monitoring networks and individual sites in recent years. Using optimized emissions/parameters, GEOS-Chem better reproduces these ground-based observations and also matches regional over-water Hg[superscript 0] and wet deposition measurements. The optimized global mercury emission to the atmosphere is ~ 5.8 Gg yr[superscript −1]. The ocean accounts for 3.2 Gg yr[superscript −1] (55% of the total), and the terrestrial ecosystem is neither a net source nor a net sink of Hg[superscript 0]. The optimized Asian anthropogenic emission of Hg[superscript 0] (gas elemental mercury) is 650–1770 Mg yr[superscript −1], higher than its bottom-up estimates (550–800 Mg yr[superscript −1]). The ocean parameter inversions suggest that dark oxidation of aqueous elemental mercury is faster, and less mercury is removed from the mixed layer through particle sinking, when compared with current simulations. Parameter changes affect the simulated global ocean mercury budget, particularly mass exchange between the mixed layer and subsurface waters. Based on our inversion results, we re-evaluate the long-term global biogeochemical cycle of mercury, and show that legacy mercury becomes more likely to reside in the terrestrial ecosystem than in the ocean. We estimate that primary anthropogenic mercury contributes up to 23 % of present-day atmospheric deposition.National Science Foundation (U.S.). Atmospheric Chemistry Program (1053648

    Impact of maternal education on response to lifestyle interventions to reduce gestational weight gain: Individual participant data meta-Analysis

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    Objectives To identify if maternal educational attainment is a prognostic factor for gestational weight gain (GWG), and to determine the differential effects of lifestyle interventions (diet based, physical activity based or mixed approach) on GWG, stratified by educational attainment. Design Individual participant data meta-Analysis using the previously established International Weight Management in Pregnancy (i-WIP) Collaborative Group database (https://iwipgroup.wixsite.com/collaboration). Preferred Reporting Items for Systematic reviews and Meta-Analysis of Individual Participant Data Statement guidelines were followed. Data sources Major electronic databases, from inception to February 2017. Eligibility criteria Randomised controlled trials on diet and physical activity-based interventions in pregnancy. Maternal educational attainment was required for inclusion and was categorised as higher education ( 65tertiary) or lower education ( 64secondary). Risk of bias Cochrane risk of bias tool was used. Data synthesis Principle measures of effect were OR and regression coefficient. Results Of the 36 randomised controlled trials in the i-WIP database, 21 trials and 5183 pregnant women were included. Women with lower educational attainment had an increased risk of excessive (OR 1.182; 95% CI 1.008 to 1.385, p =0.039) and inadequate weight gain (OR 1.284; 95% CI 1.045 to 1.577, p =0.017). Among women with lower education, diet basedinterventions reduced risk of excessive weight gain (OR 0.515; 95% CI 0.339 to 0.785, p = 0.002) and inadequate weight gain (OR 0.504; 95% CI 0.288 to 0.884, p=0.017), and reduced kg/week gain (B-0.055; 95% CI-0.098 to-0.012, p=0.012). Mixed interventions reduced risk of excessive weight gain for women with lower education (OR 0.735; 95% CI 0.561 to 0.963, p=0.026). Among women with high education, diet based interventions reduced risk of excessive weight gain (OR 0.609; 95% CI 0.437 to 0.849, p=0.003), and mixed interventions reduced kg/week gain (B-0.053; 95% CI-0.069 to-0.037,p<0.001). Physical activity based interventions did not impact GWG when stratified by education. Conclusions Pregnant women with lower education are at an increased risk of excessive and inadequate GWG. Diet based interventions seem the most appropriate choice for these women, and additional support through mixed interventions may also be beneficial

    Establishing a 'Corstonian continuous care pathway for drug using female prisoners: Linking Drug Recovery Wings and Womens Community Services

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    This article outlines the findings from a rapid assessment of pilot Drug Recovery Wings (DRWs) in two women’s prisons and compares the DRW approach with work undertaken in Women’s Community Services (WCSs) commended by the Corston Report. The findings indicate that DRW1 was working more successfully in providing a ‘Corstonian’ approach than DRW2 and the reasons behind this are explored. The article argues that, while pockets of good practice such as WCSs and ‘Corstonian’ DRWs are to be commended, unless there is a continuous care pathway, modelled on Corston’s ideas for working with vulnerable female offenders such as recovering drug users, such work will be limited in its effectiveness. Ideas for how such a systematic approach might work will be outlined

    Sources of atmospheric mercury in the tropics: continuous observations at a coastal site in Suriname

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    Mercury measurements at a coastal site in Nieuw Nickerie (5°56' N, 56°59' W), Suriname, provide the only continuous records of atmospheric mercury in the tropics. Here we evaluate observations of total gaseous mercury (TGM) during 2007. Nieuw Nickerie typically samples marine air from the Atlantic Ocean, with occasional influence from continental South America. Over the year, average concentrations are 1.40 ng m<sup>−3</sup>. As the intertropical convergence zone passes over Suriname twice each year, the site samples both northern and southern hemispheric air masses. We use back trajectories to classify each measurement by hemisphere, as well as continental or ocean. For air passing over ocean before sampling, TGM concentrations are 10% higher in air coming from the Northern Hemisphere (1.45 ng m<sup>−3</sup>) than from the Southern Hemisphere (1.32 ng m<sup>−3</sup>). Air from the South American continent also carries higher TGM (1.43 ng m<sup>−3</sup>) than air from the South Atlantic Ocean, with most of these trajectories occurring in August and September. Biomass burning in Brazil peaks in the same months and likely contributes significantly to elevated concentrations seen in Nickerie. We also compare the observed seasonal cycle to two atmospheric mercury chemistry and transport models (GRAHM and GEOS-Chem). Both models simulate transition between northern and southern hemispheric air, thus capturing the seasonal cycle; however the models overestimate the TGM concentrations during months when Nickerie samples Northern Hemisphere air. It is difficult to determine whether the models' sources or sinks in the Northern Hemisphere tropics are responsible

    Urban mercury pollution in the City of Paramaribo, Suriname

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    Religious Intent and the Art of Courteous Pleasantry: A Few Letters from Englishwomen to Heinrich Bullinger (1543-1562)

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    "Religious Intend and the Art of Courteous Pleasantry" explores the possibility of gender inclusive Reformations-narrative in light of the exchanges between Heinrich Bullinger and English women from the perspective of microhistory and the history of culture. Particularly the linguistic, historical, and theological content of the thirteen-letter correspondence between Heinrich Bullinger and Anna Hilles, Lady Jane Grey, Anne Hooper and Margaret Parkhurst is considered. Inserting the women's letters and Bullinger's replies into the larger Reformation context reveals English women of remarkable independence and dedication to the religious and political Reformation of England. The women's religious and political language signifies a collective identity of co-combatants in a missionary struggle to reform England influenced by Zurich
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