311 research outputs found

    Helping smallholder farmers mitigate climate change

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    Key messages - Smallholder farmers can contribute significantly to climate change mitigation but will need incentives to adapt their practices. - Incentives from selling carbon credits are limited by low returns to farmers, high transaction costs, and the need for farmers to invest in mitigation activities long before they receive payments. - Improved food security, economic benefits and adaptation to climate change are more fundamental incentives that should accompany mitigation. - Designing agricultural investment and policy to provide up-front finance and longer term rewards for mitigation practices will help reach larger numbers of farmers than specialized mitigation interventions

    Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Sweden 2000–2003, increasing incidence and regional differences

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    BACKGROUND: The occurrence of methicillin-resistant Staphylococcus aureus (MRSA) has gradually become more frequent in most countries of the world. Sweden has remained one of few exceptions to the high occurrence of MRSA in many other countries. During the late 1990s, Sweden experienced a large health-care associated outbreak which with resolute efforts was overcome. Subsequently, MRSA was made a notifiable diagnosis in Sweden in 2000. METHODS: From the start of being a notifiable disease in January 2000, the Swedish Institute for Infectious Disease Control (SMI) initiated an active surveillance of MRSA. RESULTS: The number of reported MRSA-cases in Sweden increased from 325 cases in 2000 to 544 in 2003, corresponding to an overall increase in incidence from 3.7 to 6.1 per 100000 inhabitants. Twenty five per cent of the cases were infected abroad. The domestic cases were predominantly found through cultures taken on clinical indication and the cases infected abroad through screening. There were considerable regional differences in MRSA-incidence and age-distribution of cases. CONCLUSION: The MRSA incidence in Sweden increased over the years 2000–2003. Sweden now poises on the rim of the same development that was seen in the United Kingdom some ten years ago. A quarter of the cases were infected abroad, reflecting that international transmission is now increasingly important in a low-endemic setting. To remain in this favourable situation, stepped up measures will be needed, to identify imported cases, to control domestic outbreaks and to prevent transmission within the health-care sector

    Differential modes of DNA binding by mismatch uracil DNA glycosylase from Escherichia coli: implications for abasic lesion processing and enzyme communication in the base excision repair pathway

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    Mismatch uracil DNA glycosylase (Mug) from Escherichia coli is an initiating enzyme in the base-excision repair pathway. As with other DNA glycosylases, the abasic product is potentially more harmful than the initial lesion. Since Mug is known to bind its product tightly, inhibiting enzyme turnover, understanding how Mug binds DNA is of significance when considering how Mug interacts with downstream enzymes in the base-excision repair pathway. We have demonstrated differential binding modes of Mug between its substrate and abasic DNA product using both band shift and fluorescence anisotropy assays. Mug binds its product cooperatively, and a stoichiometric analysis of DNA binding, catalytic activity and salt-dependence indicates that dimer formation is of functional significance in both catalytic activity and product binding. This is the first report of cooperativity in the uracil DNA glycosylase superfamily of enzymes, and forms the basis of product inhibition in Mug. It therefore provides a new perspective on abasic site protection and the findings are discussed in the context of downstream lesion processing and enzyme communication in the base excision repair pathway

    A comparative study of uracil-DNA glycosylases from human and herpes simplex virus type 1

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    Uracil-DNA glycosylase (UNG) is the key enzyme responsible for initiation of base excision repair. We have used both kinetic and binding assays for comparative analysis of UNG enzymes from humans and herpes simplex virus type 1 (HSV-1). Steady-state fluorescence assays showed that hUNG has a much higher specificity constant (kcat/Km) compared with the viral enzyme due to a lower Km. The binding of UNG to DNA was also studied using a catalytically inactive mutant of UNG and non-cleavable substrate analogs (2′-deoxypseudouridine and 2′-α-fluoro-2′-deoxyuridine). Equilibrium DNA binding revealed that both human and HSV-1 UNG enzymes bind to abasic DNA and both substrate analogs more weakly than to uracil-containing DNA. Structure determination of HSV-1 D88N/H210N UNG in complex with uracil revealed detailed information on substrate binding. Together, these results suggest that a significant proportion of the binding energy is provided by specific interactions with the target uracil. The kinetic parameters for human UNG indicate that it is likely to have activity against both U·A and U·G mismatches in vivo. Weak binding to abasic DNA also suggests that UNG activity is unlikely to be coupled to the subsequent common steps of base excision repair

    Affective cognition in bipolar disorder: A systematic review by the ISBD targeting cognition task force

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    Background: Impairments in affective cognition are part of the neurocognitive profile and possible treatment targets in bipolar disorder (BD), but the findings are heterogeneous. The International Society of Bipolar Disorder (ISBD) Targeting Cognition Task Force conducted a systematic review to (i) identify the most consistent findings in affective cognition in BD, and (ii) provide suggestions for affective cognitive domains for future study and meta‐analyses.Methods: The review included original studies reporting behavioral measures of affective cognition in BD patients vs controls following the procedures of the Preferred Reporting Items for Systematic reviews and Meta‐Analysis (PRISMA) statement. Searches were conducted on PubMed/MEDLINE, EMBASE, and PsychInfo from inception until November 2018.Results: A total of 106 articles were included (of which nine included data for several affective domains); 41 studies assessed emotional face processing; 23 studies investigated reactivity to emotional words and images; 3 investigated explicit emotion regulation; 17 assessed implicit emotion regulation; 31 assessed reward processing and affective decision making. In general, findings were inconsistent. The most consistent findings were trait‐related difficulties in facial emotion recognition and implicit emotion regulation, and impairments in reward processing and affective decision making during mood episodes. Studies using eye‐tracking and facial emotion analysis revealed subtle trait‐related abnormalities in emotional reactivity.Conclusion: The ISBD Task Force recommends facial expression recognition, implicit emotion regulation, and reward processing as domains for future research and meta‐analyses. An important step to aid comparability between studies in the field would be to reach consensus on an affective cognition test battery for BD

    Importance and controls of anaerobic ammonium oxidation influenced by riverbed geology

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    Rivers are an important global sink for excess bioavailable nitrogen: they convert approximately 40% of terrestrial N runoff per year (∼47 Tg) to biologically unavailable N 2 gas and return it to the atmosphere. At present, riverine N 2 production is conceptualized and modelled as denitrification. Anaerobic ammonium oxidation, known as anammox, is an alternative pathway of N 2 production important in marine environments, but its contribution to riverine N 2 production is not well understood. Here we use in situ and laboratory measurements of anammox activity using 15 N tracers and molecular analyses of microbial communities to evaluate anammox in clay-, sand-and chalk-dominated river beds in the Hampshire Avon catchment, UK during summer 2013. Abundance of the hzo gene, which encodes an enzyme central to anammox metabolism, varied across the contrasting geologies. Anammox rates were similar across geologies but contributed different proportions of N 2 production because of variation in denitrification rates. In spite of requiring anoxic conditions, anammox, most likely coupled to partial nitrification, contributed up to 58% of in situ N 2 production in oxic, permeable riverbeds. In contrast, denitrification dominated in low-permeability clay-bed rivers, where anammox contributes roughly 7% to the production of N 2 gas. We conclude that anammox can represent an important nitrogen loss pathway in permeable river sediments

    Transnational Investments of the Tunisian Diaspora: Trajectories, Skills Accumulation and Constraints

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    This chapter is based on recent empirical data on Tunisians living in Switzerland. It focuses on their migration pathways and experiences, and it examines their propensity to engage in entrepreneurial and business activities in their home country. Despite the hopes generated by the revolution of 2011, there are many people in Tunisia, especially young males from disadvantaged regions, who have not enjoyed the positive changes in employment opportunities and professional prospects. This has led them to them emigrate to Europe to ensure an income for themselves and their families back in Tunisia. An online survey accompanied by follow-up interviews enabled us to observe the experiences of Tunisian diaspora entrepreneurs and their current and potential future transnational business and investment activities. This chapter shows how the internationalization and accumulation of networks and skills by Tunisians, resulting from the multiple destinations they traversed before arriving to Switzerland, has influenced their professional capacities and their business and entrepreneurial projects in Tunisia. Tunisians feel a strong motivation to contribute to the development process in their home country, and they tend to invest and open businesses in their villages of origin. Several enablers and obstacles that influence their actions are observed. A number of policy recommendations based on the experiences and aspirations of these Tunisians are included in the conclusions
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