130 research outputs found

    Missing OH source in a suburban environment near Beijing: observed and modelled OH and HO2 concentrations in summer 2006

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    Measurements of ambient OH and HO2 radicals were performed by laser induced fluorescence (LIF) during CAREBeijing2006 (Campaigns of Air Quality Research in Beijing and Surrounding Region 2006) at the suburban site Yufa in the south of Beijing in summer 2006. On most days, local air chemistry was influenced by aged air pollution that was advected by a slow, almost stagnant wind from southern regions. Observed daily concentration maxima were in the range of (4–17) × 106 cm−3 for OH and (2–24) × 108 cm−3 for HO2 (including an estimated interference of 25% from RO2). During daytime, OH reactivities were generally high (10–30 s−1) and mainly contributed by observed VOCs and their calculated oxidation products. The comparison of modelled and measured HOx concentrations reveals a systematic underprediction of OH as a function of NO. A large discrepancy of a factor 2.6 is found at the lowest NO concentration encountered (0.1 ppb), whereas the discrepancy becomes insignificant above 1 ppb NO. This study extends similar observations from the Pearl-River Delta (PRD) in South China to a more urban environment. The OH discrepancy at Yufa can be resolved, if NO-independent additional OH recycling is assumed in the model. The postulated Leuven Isoprene Mechanism (LIM) has the potential to explain the gap between modelled and measured OH at Beijing taking into account conservative error estimates, but lacks experimental confirmation. This and the hereby unresolved discrepancy at PRD suggest that other VOCs besides isoprene might be involved in the required, additional OH recycling. Fast primary production of ROx radicals up to 7 ppb h−1 was determined at Beijing which was dominated by the photolysis of O3, HONO, HCHO, and dicarbonyls. For a special case, 20 August, when the plume of Beijing city was encountered, a missing primary HOx source (about 3 ppb h−1) was determined under high NOx conditions similar to other urban areas like Mexico City. CAREBeijing2006 emphasizes the important role of OVOCs as a radical source and sink, and the need for further investigation of the chemical degradation of VOCs in order to better understand radical chemistry in VOC-rich air

    The smoking cessation in pregnancy incentives trial (CPIT): study protocol for a phase III randomised controlled trial

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    Background: Eighty per cent of UK women have at least one baby, making pregnancy an opportunity to help women stop smoking before their health is irreparably compromised. Smoking cessation during pregnancy helps protect infants from miscarriage, still birth, low birth weight, asthma, attention deficit disorder and adult cardiovascular disease. UK national guidelines highlight lack of evidence for effectiveness of financial incentives to help pregnant smokers quit. This includes a research recommendation: within a UK context, are incentives an acceptable, effective and cost-effective way to help pregnant women who smoke to quit? Methods: The Cessation in Pregnancy Incentives Trial (CPIT) III is a pragmatic, 42-month, multi-centre, parallel-group, individually randomised controlled superiority trial of the effect on smoking status of adding to usual Stop Smoking Services (SSS) support, the offer of up to £400 of financial voucher incentives, compared with usual support alone, to quit smoking during pregnancy. Participants (n = 940) are pregnant smokers (age > 16 years, < 24 weeks pregnant, English speaking), who consent via telephone to take part and are willing to be followed-up in late pregnancy and 6 months after birth. The primary outcome is cotinine/anabasine-validated abstinence from smoking in late pregnancy. Secondary outcomes include engagement with SSS, quit rates at 4 weeks from agreed quit date and 6 months after birth, and birth weight. Outcomes will be analysed by intention to treat, and regression models will be used to compare treatment effects on outcomes. A meta-analysis will include data from the feasibility study in Glasgow. An economic evaluation will assess cost-effectiveness from a UK NHS perspective. Process evaluation using a case-study approach will identify opportunities to improve recruitment and learning for future implementation. Research questions include: what is the therapeutic efficacy of incentives; are incentives cost-effective; and what are the potential facilitators and barriers to implementing incentives in different parts of the UK? Discussion: This phase III trial in Scotland, England and Northern Ireland follows a successful phase II trial in Glasgow, UK. The participating sites have diverse SSS that represent most cessation services in the UK and serve demographically varied populations. If found to be acceptable and cost-effective, this trial could demonstrate that financial incentives are effective and transferable to most UK SSS for pregnant women. Trial registration: Current Controlled Trials, ISRCTN15236311. Registered on 9 October 2017

    CASPER plus (CollAborative care in Screen-Positive EldeRs with major depressive disorder): study protocol for a randomised controlled trial

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    Background: Depression accounts for the greatest disease burden of all mental health disorders, contributes heavily to healthcare costs, and by 2020 is set to become the second largest cause of global disability. Although 10% to 16% of people aged 65 years and over are likely to experience depressive symptoms, the condition is under-diagnosed and often inadequately treated in primary care. Later-life depression is associated with chronic illness and disability, cognitive impairment and social isolation. With a progressively ageing population it becomes increasingly important to refine strategies to identity and manage depression in older people. Currently, management may be limited to the prescription of antidepressants where there may be poor concordance; older people may lack awareness of psychosocial interventions and general practitioners may neglect to offer this treatment option. Methods/design: CASPER Plus is a multi-centre, randomised controlled trial of a collaborative care intervention for individuals aged 65 years and over experiencing moderate to severe depression. Selected practices in the North of England identify potentially eligible patients and invite them to participate in the study. A diagnostic interview is carried out and participants with major depressive disorder are randomised to either collaborative care or usual care. The recruitment target is 450 participants. The intervention, behavioural activation and medication management in a collaborative care framework, has been adapted to meet the complex needs of older people. It is delivered over eight to 10 weekly sessions by a case manager liaising with general practitioners. The trial aims to evaluate the clinical and cost effectiveness of collaborative care in addition to usual GP care versus usual GP care alone. The primary clinical outcome, depression severity, will be measured with the Patient Health Questionnaire-9 (PHQ-9) at baseline, 4, 12 and 18 months. Cost effectiveness analysis will assess health-related quality of life using the SF-12 and EQ-5D and will examine cost-consequences of collaborative care. A qualitative process evaluation will be undertaken to explore acceptability, gauge the extent to which the intervention is implemented and to explore sustainability beyond the clinical trial. Discussion: Results will add to existing evidence and a positive outcome may lead to the commissioning of this model of service in primary care. Trial registration: ISRCTN45842879 (24 July 2012)

    Understanding the roles of forests and tree-based systems in food provision

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    Forests and other tree-based systems such as agroforestry contribute to food and nutritional security in myriad ways. Directly, trees provide a variety of healthy foods including fruits, leafy vegetables, nuts, seeds and edible oils that can diversify diets and address seasonal food and nutritional gaps. Forests are also sources of a wider range of edible plants and fungi, as well as bushmeat, fish and insects. Treebased systems also support the provision of fodder for meat and dairy animals, of “green fertiliser” to support crop production and of woodfuel, crucial in many communities for cooking food. Indirectly, forests and tree-based systems are a source of income to support communities to purchase foods and they also provide environmental services that support crop production. There are, however, complexities in quantifying the relative benefits and costs of tree-based systems in food provision. These complexities mean that the roles of tree-based systems are often not well understood. A greater understanding focuses on systematic methods for characterising effects across different landscapes and on key indicators, such as dietary diversity measures. This chapter provides a number of case studies to highlight the relevance of forests and tree-based systems for food security and nutrition, and indicates where there is a need to further quantify the roles of these systems, allowing proper integration of their contribution into national and international developmental policies

    An economic evaluation of Alexander Technique lessons or acupuncture sessions for patients with chronic neck pain : A randomized trial (ATLAS)

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    OBJECTIVES: To assess the cost-effectiveness of acupuncture and usual care, and Alexander Technique lessons and usual care, compared with usual GP care alone for chronic neck pain patients. METHODS: An economic evaluation was undertaken alongside the ATLAS trial, taking both NHS and wider societal viewpoints. Participants were offered up to twelve acupuncture sessions or twenty Alexander lessons (equivalent overall contact time). Costs were in pounds sterling. Effectiveness was measured using the generic EQ-5D to calculate quality adjusted life years (QALYs), as well as using a specific neck pain measure-the Northwick Park Neck Pain Questionnaire (NPQ). RESULTS: In the base case analysis, incremental QALY gains were 0.032 and 0.025 in the acupuncture and Alexander groups, respectively, in comparison to usual GP care, indicating moderate health benefits for both interventions. Incremental costs were £451 for acupuncture and £667 for Alexander, mainly driven by intervention costs. Acupuncture was likely to be cost-effective (ICER = £18,767/QALY bootstrapped 95% CI £4,426 to £74,562) and was robust to most sensitivity analyses. Alexander lessons were not cost-effective at the lower NICE threshold of £20,000/QALY (£25,101/QALY bootstrapped 95% CI -£150,208 to £248,697) but may be at £30,000/QALY, however, there was considerable statistical uncertainty in all tested scenarios. CONCLUSIONS: In comparison with usual care, acupuncture is likely to be cost-effective for chronic neck pain, whereas, largely due to higher intervention costs, Alexander lessons are unlikely to be cost-effective. However, there were high levels of missing data and further research is needed to assess the long-term cost-effectiveness of these interventions

    Does crop diversity contribute to dietary diversity? Evidence from integration of vegetables into maize-based farming systems

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    Background: Maize is the most important staple crop for food security and livelihood of smallholder farmers in many parts of sub-Saharan Africa, but it alone cannot ensure food security. Cropping patterns must be diversified to ensure an adequate supply and economic access to greater variety of foods for smallholder farm households. This study measured the effect of crop diversification on household dietary diversity in a selected study locale using a survey of 300 randomly stratified farm households in 10 villages located in the Babati, Kongwa and Kiteto districts of Tanzania. Results: Based on multiple regression analysis, the study found that simply increasing Simpson’s Index does not influence dietary diversity of farm households due to the presence of interaction effect between Simpson’s Index and crop income. It is much more critical and significant to increase the revenue generated from diversified crops along with other socioeconomic endowment and behavioral characteristics of farm households. This is particularly applicable to poorer smallholder farmers who receive crop income less than US$85 per sales transaction and per season. Particularly, marginal and smallholders might be exposed to the effects of crop diversification and crop income toward increasing in their household dietary diversity score. Conclusion: Under average crop income scenarios, households that diversify their crop production tend to increase their dietary diversity from their existing dietary diversity score at a decreasing rate. However, under below average crop income threshold scenarios, farmers tend to increase their dietary diversity score from their existing score at an increasing rate when they diversify into high-value crops that attract relatively high farm gate values and accrue higher net revenues from the market. Monthly food expenditure also tends to positively influence household dietary diversity, indicating that farm households that spend more on market-purchased food have consistent increases in their dietary diversity scores at the household level. This study concludes that improving economic access to variety of foods at the smallholder household level by diversifying diets through increased crop diversification should be encouraged within maize-based farming systems of the study locale, through integration of micronutrient-rich foods such as vegetables

    Cytisine for smoking cessation in patients with tuberculosis: a multicentre, randomised, double-blind, placebo-controlled phase 3 trial

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    Dogar O, Keding A, Gabe R, et al. Cytisine for smoking cessation in patients with tuberculosis: a multicentre, randomised, double-blind, placebo-controlled phase 3 trial. The Lancet. Global health. 2020;8(11):e1408-e1417.BACKGROUND: Smoking cessation is important in patients with tuberculosis because it can reduce the high rates of treatment failure and mortality. We aimed to assess the effectiveness and safety of cystine as a smoking cessation aid in patients with tuberculosis in Bangladesh and Pakistan.; METHODS: We did a randomised, double-blind, placebo-controlled, trial at 32 health centres in Bangladesh and Pakistan. Eligible patients were adults (aged >18 years in Bangladesh; aged >15 years in Pakistan) with pulmonary tuberculosis diagnosed in the previous 4 weeks, who smoked tobacco on a daily basis and were willing to stop smoking. Patients were randomly assigned (1:1) to receive behavioural support plus either oral cytisine (9 mg on day 0, which was gradually reduced to 1·5 mg by day 25) or placebo for 25 days. Randomisation was done using pregenerated block randomisation lists, stratified by trial sites. Investigators, clinicians, and patients were masked to treatment allocation. The primary outcome was continuous abstinence at 6 months, defined as self-report (of not having used more than five cigarettes, bidis, a water pipe, or smokeless tobacco products since the quit date), confirmed biochemically by a breath carbon monoxide reading of less than 10 parts per million. Primary and safety analysis were done in the intention-to-treat population. This trial is registered with the International Standard Randomised Clinical Trial Registry, ISRCTN43811467, and enrolment is complete.; FINDINGS: Between June 6, 2017, and April 30, 2018, 2472 patients (1527 patients from Bangladesh; 945 patients from Pakistan) were enrolled and randomly assigned to receive cytisine (n=1239) or placebo (n=1233). At 6 months, 401 (32·4%) participants in the cytisine group and 366 (29·7%) participants in the placebo group had achieved continuous abstinence (risk difference 2·68%, 95% CI -0·96 to 6·33; relative risk 1·09, 95% CI 0·97 to 1·23, p=0·114). 53 (4·3%) of 1239 participants in the cytisine group and 46 (3·7%) of 1233 participants in the placebo group reported serious adverse events (94 events in the cytisine group and 90 events in the placebo group), which included 91 deaths (49 in the cytisine group and 42 in the placebo group). None of the adverse events were attributed to the study medication.; INTERPRETATION: Our findings do not support the addition of cytisine to brief behavioural support for the treatment of tobacco dependence in patients with tuberculosis.; FUNDING: European Union Horizon 2020 and Health Data Research UK.; TRANSLATIONS: For the Bengali and Urdu translations of the abstract see Supplementary Materials section. Copyright © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved
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