Despite its theoretical prominence and sound principles, integrated pest management (IPM) continues to suffer from anemic adoption rates in developing countries. To shed light on the reasons, we surveyed the opinions of a large and diverse pool of IPM professionals and practitioners from 96 countries by using structured concept mapping. The first phase of this method elicited 413 open-ended responses on perceived obstacles to IPM. Analysis of responses revealed 51 unique statements on obstacles, the most frequent of which was "insufficient training and technical support to farmers." Cluster analyses, based on participant opinions, grouped these unique statements into six themes: research weaknesses, outreach weaknesses, IPM weaknesses, farmer weaknesses, pesticide industry interference, and weak adoption incentives. Subsequently, 163 participants rated the obstacles expressed in the 51 unique statements according to importance and remediation difficulty. Respondents from developing countries and high-income countries rated the obstacles differently. As a group, developing-country respondents rated "IPM requires collective action within a farming community" as their top obstacle to IPM adoption. Respondents from high-income countries prioritized instead the "shortage of well-qualified IPM experts and extensionists." Differential prioritization was also evident among developing-country regions, and when obstacle statements were grouped into themes. Results highlighted the need to improve the participation of stakeholders from developing countries in the IPM adoption debate, and also to situate the debate within specific regional contexts. sustainable agriculture | technology adoption | collective action dilemma

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A series of novel 2-arylbenzoxazoles that upregulate the production of utrophin in murine H2K cells, as assessed using a luciferase reporter linked assay, have been identified. This compound class appears to hold considerable promise as a potential treatment for Duchenne muscular dystrophy. Following the delineation of structure-activity relationships in the series, a number of potent upregulators were identified, and preliminary ADME evaluation is described. These studies have resulted in the identification of 1, a compound that has been progressed to clinical trials.

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A mathematical model was developed of the dynamics of a plant virus disease within a spatially-referenced lattice of fields of a host crop. The model can be applied to crops in continuous, contiguous cultivation such as tropical irrigated rice. Disease progress in each field of the host crop was assumed to be logistic and determined by incidence within the field itself as well as incidence in neighbouring fields, depending on the gradient of disease spread. The frequency distribution of planting dates (represented by the proportion of the total number of fields planted in successive months) was assumed to follow a normal distribution and the variance of planting date was used as a measure of cropping asynchrony. Analysis of the model revealed that disease incidence within the lattice (i.e. mean incidence over all fields) depended upon the infection efficiency, the slope of the dispersal gradient, and the variance in planting date. Disease endemicity depended mainly on planting date variance and disease persisted in the lattice if this variance exceeded a certain threshold. Above the threshold for persistence, the response of mean disease incidence to planting date variance was non-linear and the region of greatest sensitivity was closest to the threshold. Thus, disease systems that show moderate rather than high cropping asynchrony are more likely to be influenced by changes in the variance of planting date. Implications for the area-wide management of rice tungro virus disease are discussed.

A dynamic cropping system was represented by a square lattice of ®elds in which crops were successively harvested and replanted. A spectrum of crop ages existed at any one time and the virus disease persisted by spread of inoculum between crops. Such a situation is typical of many areas of tropical irrigated rice cultivation in which rice tungro virus disease (RTVD) occurs. Using a mathematical model of the epidemiology of RTVD in the cropping system, the deployment of ®elds of a genotype expressing some resistance to the disease was investigated. Previous studies on the effect of genotype mixtures on disease progress within a single crop have shown that both the rate of disease increase and the rate of focus expansion were proportional to the logarithm of the fraction of susceptible plants in the mixture. Here, looking at long-term disease incidence in a dynamic cropping system, it was found that this same`logarithmic rule' applied, provided that resistant crop deployment was spatially random. A relatively large proportion of ®elds had to be planted with resistant varieties in order to have suf®cient area-wide impact on inoculum to reduce disease incidence in ®elds of susceptible varieties. In many rice cropping systems there are two growing seasons per year and the modelling indicated that the best strategy was to concentrate deployment of resistant varieties in the season of greatest disease spread. Attempts to minimize inoculum carry-over to the`high spread' season by concentrating resistant varieties in the previous season had little effect over a range of simulated conditions. In considering recommendations for the management of RTVD, a con¯ict existed between the reduction of disease incidence strategically and in the individual ®elds of a newly deployed variety. To maximize area-wide strategic impact, small genotype units and random patterns were best, but to protect individual ®elds, large units and concentrated deployment were best.