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Nicotinic acetylcholine receptors are ligand-gated transmembrane ion channels that are present at the neuromuscular junction and in different locations in the nervous system. The different subtypes of neuronal nicotinic acetylcholine receptors that are found in the brain are thought to be involved in many neurological processes such as pain, cognitive function and depression, as well as in the pathophysiology of numerous neurological diseases and conditions. While the neurotransmitter acetylcholine is an endogenous agonist for all nicotinic receptors subtypes, many drugs that act as agonists and antagonists have also been identified or developed for these receptors. In addition, a novel class of compounds described as allosteric modulators have also been identified or developed for nicotinic acetylcholine receptors. Allosteric modulators are ligands that bind to nicotinic receptors at sites other than the orthosteric site where acetylcholine binds. One such allosteric modulator is desformylflustrabromine. Five chemical analogs along with desformylflustrabromine act as positive allosteric modulator for nAChRs that contain the beta2 subunit in their pentameric structure. Here the discovery and development, medicinal chemistry and pharmacological actions of desformylflustrabromine have been discussed. Desformylflustrabromine and its chemical analogs have the potential to develop into clinically used drugs for neurological diseases and conditions where nicotinic acetylcholine receptors are involved. © 2016 Bentham Science Publishers.

Schipmann C.,International Crops Research Institute for the Semi Arid Tropics ICRISAT | Qaim M.,Rural University
Food Policy | Year: 2011

There is an emerging body of literature analyzing how smallholder farmers in developing countries can be linked to modern supply chains. However, most of the available studies concentrate on farm and farmer characteristics, failing to capture details of institutional arrangements between farmers and traders. Moreover, farmers' preferences have rarely been considered. Here, we address these gaps by analyzing different market channels for sweet pepper in Thailand. Using data from a survey and choice experiment with farmers, we find that there is a general preference for marketing options that do not involve a contract. Additional provision of inputs and credit can increase the attractiveness of contracts. Yet, the most important factor for farmers is to personally know the buyer they deal with, which may be related to issues of trust. Some policy implications are discussed. © 2011 Elsevier Ltd.

Seal C.J.,Northumbria University | Brownlee I.A.,Rural University
Proceedings of the Nutrition Society | Year: 2015

Cereal-based foods are key components of the diet and they dominate most food-based dietary recommendations in order to achieve targets for intake of carbohydrate, protein and dietary fibre. Processing (milling) of grains to produce refined grain products removes key nutrients and phytochemicals from the flour and although in some countries nutrients may be replaced with mandatory fortification, overall this refinement reduces their potential nutritional quality. There is increasing evidence from both observational and intervention studies that increased intake of less-refined, whole-grain (WG) foods has positive health benefits. The highest WG consumers are consistently shown to have lower risk of developing CVD, type 2 diabetes and some cancers. WG consumers may also have better digestive health and are likely to have lower BMI and gain less weight over time. The bulk of the evidence for the benefits of WG comes from observational studies, but evidence of benefit in intervention studies and potential mechanisms of action is increasing. Overall this evidence supports the promotion of WG foods over refined grain foods in the diet, but this would require adoption of standard definitions of 'whole grain' and 'whole-grain foods' which will enable innovation by food manufacturers, provide clarity for the consumer and encourage the implementation of food-based dietary recommendations and public health strategies. Copyright © The Authors 2015.

Odours constitute a problem when they affect the health of those exposed or when their character and intensity cause annoyance. Odour concentration and the hedonic tone of odours are of interest when setback models are used to predict annoyance in the neighbourhood of odour emitting operations. An experiment was made with the objective of studying the relationship between the odour concentration and the hedonic tone of odours from pig, poultry and dairy operations. A further objective was to identify individual factors of importance for rating of the hedonic tone. A panel of 16 persons was engaged to rate the hedonic tone and for each panel member the individual odour threshold for n-butanol was estimated. Odour samples from poultry and livestock buildings were analysed for odour concentration following European guidelines. The panel members rated the hedonic tone of various odour concentrations. Odour concentration explained much of the hedonic tone of odour from pigs, pig manure and laying hens. For Odour from dairy cows, the odour concentration explained comparatively less. On a hedonic scale, where 0 is neutral and -4 is extremely unpleasant, an odour concentration of 14-16 European odour units (ouE) m-3 from pig and poultry houses was rated to -1. On the same scale, an odour concentration of 37 ouE m-3 from a cow shed was rated to -1. Individual odour thresholds were found to be important for rating of the hedonic tone. The rating of the hedonic tone showed similarity to odour intensities reported in other studies. © 2010 IAgrE.

Cumming G.S.,University of Cape Town | Buerkert A.,University of Kassel | Hoffmann E.M.,University of Kassel | Schlecht E.,University of Gottingen | And 2 more authors.
Nature | Year: 2014

Historically, farmers and hunter-gatherers relied directly on ecosystem services, which they both exploited and enjoyed. Urban populations still rely on ecosystems, but prioritize non-ecosystem services (socioeconomic). Population growth and densification increase the scale and change the nature of both ecosystem- and non-ecosystem-service supply and demand, weakening direct feedbacks between ecosystems and societies and potentially pushing social-ecological systems into traps that can lead to collapse. The interacting and mutually reinforcing processes of technological change, population growth and urbanization contribute to over-exploitation of ecosystems through complex feedbacks that have important implications for sustainable resource use. © 2014 Macmillan Publishers Limited. All rights reserved.

Sibhatu K.T.,Rural University | Krishna V.V.,Rural University | Qaim M.,Rural University
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

Undernutrition and micronutrient malnutrition remain problems of significant magnitude in large parts of the developing world. Improved nutrition requires not only better access to food for poor population segments, but also higher dietary quality and diversity. Because many of the poor and undernourished people are smallholder farmers, diversifying production on these smallholder farms is widely perceived as a useful approach to improve dietary diversity. However, empirical evidence on the link between production and consumption diversity is scarce. Here, this issue is addressed with household-level data from Indonesia, Kenya, Ethiopia, and Malawi. Regression models show that on-farm production diversity is positively associated with dietary diversity in some situations, but not in all. When production diversity is already high, the association is not significant or even turns negative, because of foregone income benefits from specialization. Analysis of other factors reveals that market access has positive effects on dietary diversity, which are larger than those of increased production diversity. Market transactions also tend to reduce the role of farm diversity for household nutrition. These results suggest that increasing on-farm diversity is not always the most effective way to improve dietary diversity in smallholder households and should not be considered a goal in itself. Additional research is needed to better understand how agriculture and food systems can be made more nutrition-sensitive in particular situations.

Klumper W.,Rural University | Qaim M.,Rural University
PLoS ONE | Year: 2014

Background: Despite the rapid adoption of genetically modified (GM) crops by farmers in many countries, controversies about this technology continue. Uncertainty about GM crop impacts is one reason for widespread public suspicion. Copyright:Objective: We carry out a meta-analysis of the agronomic and economic impacts of GM crops to consolidate the evidence.Data Sources: Original studies for inclusion were identified through keyword searches in ISI Web of Knowledge, Google Scholar, EconLit, and AgEcon Search.Study Eligibility Criteria: Studies were included when they build on primary data from farm surveys or field trials anywhere in the world, and when they report impacts of GM soybean, maize, or cotton on crop yields, pesticide use, and/or farmer profits. In total, 147 original studies were included.Synthesis Methods: Analysis of mean impacts and meta-regressions to examine factors that influence outcomes.Results: On average, GM technology adoption has reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68%. Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries.Limitations: Several of the original studies did not report sample sizes and measures of variance.Conclusion: The meta-analysis reveals robust evidence of GM crop benefits for farmers in developed and developing countries. Such evidence may help to gradually increase public trust in this technology. © 2014 Klümper, Qaim.

Kouser S.,Rural University | Qaim M.,Rural University
Ecological Economics | Year: 2011

While substantial research on the productivity and profit effects of Bt cotton has been carried out recently, the economic evaluation of positive and negative externalities has received much less attention. Here, we focus on farmer health impacts resulting from Bt-related changes in chemical pesticide use. Previous studies have documented that Bt cotton has reduced the problem of pesticide poisoning in developing countries, but they have failed to account for unobserved heterogeneity between technology adopters and non-adopters. We use unique panel survey data from India to estimate unbiased effects and their developments over time. Bt cotton has reduced pesticide applications by 50%, with the largest reductions of 70% occurring in the most toxic types of chemicals. Results of fixed-effects Poisson models confirm that Bt has notably reduced the incidence of acute pesticide poisoning among cotton growers. These effects have become more pronounced with increasing technology adoption rates. Bt cotton now helps to avoid several million cases of pesticide poisoning in India every year, which also entails sizeable health cost savings. © 2011 Elsevier B.V.

Wolbert-Haverkamp M.,Rural University | Musshoff O.,Rural University
Land Use Policy | Year: 2014

Short rotation coppice (SRC) is intensively discussed as being an economical and ecological advantageous alternative to traditional agricultural land use. In various countries, farmers have been encouraged through incentives to cultivate SRC. Nevertheless, they often do not switch from conventional land use to SRC, even if SRC is relatively beneficial according to the net present value (NPV) rule. Therefore, farmers do not follow the classical investment theory. A relatively new theory is the real options approach (ROA). The ROA takes further aspects like irreversibility of the investment costs, flexibility regarding investment timing, and uncertainty of the investment returns into account, which the NPV rule ignores. In the case of SRC, investment (conversion) triggers when a farmer should switch to SRC following the ROA can be higher than those following the NPV rule. As it is often the case in real options applications, decision makers' possibility to disinvest in general and farmers' possibility to reconvert, in particular within the useful lifetime of SRC, is not considered. We build a model to calculate the conversion triggers for switching from annual crop production to SRC following the ROA. We consider the opportunity to reconvert the land and evaluate the respective effects on the conversion triggers according to the ROA. Furthermore, we analyze the effect of a former governmental incentive, in terms of an investment subsidy, on the conversion triggers of both theories. Our calculations show that following the ROA, a farmer should change land use to SRC more slowly than when following the NPV rule. Furthermore, neglecting the reconversion possibility would cause considerable bias amongst the results. The consideration of investment subsidies diminishes the conversion triggers of both theories. We conclude that the ROA can at least partially explain farmers' inertia of converting to SRC. © 2013 Elsevier Ltd.

Krishna V.V.,International Maize and Wheat Improvement Center | Qaim M.,Rural University
Agricultural Systems | Year: 2012

Studies from different countries show that transgenic Bacillus thuringiensis (Bt) crops can reduce chemical pesticide use with positive economic, environmental, and health effects. However, most of these studies build on cross-section survey data, so that longer term effects have not been analyzed. Bt resistance and secondary pest outbreaks may potentially reduce or eliminate the benefits over time, especially in developing countries where refuge strategies are often not implemented. Here, we use data from a unique panel survey of cotton farmers conducted in India between 2002 and 2008. Accounting for possible selection bias, we show that the Bt pesticide reducing effect has been sustainable. In spite of an increase in pesticide sprays against secondary pests, total pesticide use has decreased significantly over time. Bt has also reduced pesticide applications by non-Bt farmers. These results mitigate the concern that Bt technology would soon become obsolete in small farmer environments. The survey data on actual pesticide use in farmers' fields complement previous entomological research. © 2011 Elsevier Ltd.

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