SUMMARYHundreds of small-scale influenza outbreaks in schools are reported in mainland China every year, leading to a heavy disease burden which seriously impacts the operation of affected schools. Knowing the transmissibility of each outbreak in the early stage has become a major concern for public health policy-makers and primary healthcare providers. In this study, we collected all the small-scale outbreaks in Changsha (a large city in south central China with ~7·04 million population) from January 2005 to December 2013. Four simple and popularly used models were employed to calculate the reproduction number (R) of these outbreaks. Given that the duration of a generation interval Tc = 2·7 and the standard deviation (s.d.) σ = 1·1, the mean R estimated by an epidemic model, normal distribution and delta distribution were 2·51 (s.d. = 0·73), 4·11 (s.d. = 2·20) and 5·88 (s.d. = 5·00), respectively. When Tc = 2·9 and σ = 1·4, the mean R estimated by the three models were 2·62 (s.d. = 0·78), 4·72 (s.d. = 2·82) and 6·86 (s.d. = 6·34), respectively. The mean R estimated by gamma distribution was 4·32 (s.d. = 2·47). We found that the values of R in small-scale outbreaks in schools were higher than in large-scale outbreaks in a neighbourhood, city or province. Normal distribution, delta distribution, and gamma distribution models seem to more easily overestimate the R of influenza outbreaks compared to the epidemic model.

This meta-analysis demonstrates a significant association between PD1.3A and SLE among non-Spanish European descents, while a negative association was observed in Spanish population.

Improving farmers’ welfare has been the concern of the government and international donors in sub-Saharan Africa and particularly in Cameroon. Encouraging farmers to adopt agricultural extension services is one of the most important measures implemented to improve the rural farmers’ welfare situation. Thus, the main aim of our study is to assess the impact of the adoption of agricultural extension services on the welfare (food security) of smallholder rural farmers in the Centre region of Cameroon. Our study employs the endogenous switching regression model to account for both selection and endogeneity bias on survey data obtained from two divisions in the Centre region of Cameroon. Using Household Dietary Diversity Score (HDDS) as a measure of our food security access indicator, results suggest that adoption of agricultural extension services significantly reduces the HDDS of farmers’ households by 0.267 points at 5 percent significance level. This result demonstrates that adopting agricultural extension services doesn’t improve the diversity of nutritional intake by rural farm households thereby suggesting the benefits obtained from income does not always lead to the consumption of diverse nutritional food. Given that food security has no standard measurement, extension services adoption could, however, improve other aspects of food security.

Pfitzinger (1-benzylpiperidin-4-one with 7-methylisatin) and Friedlander (3-aminopyridine-4-carbaldehyde with 2-methylcyclohexanone) syntheses, respectively, were used to prepare the title 'azaacridines' containing a methyl substituent peri to the central nitrogen. Oxidation of this group gave the corresponding aldehyde and carboxylic acid. In the [1,6] case, especially, the 10-position was also easily oxidized to give acridone analogues. Nitration occurred exclusively in the benzenoid rings.

Some comparisons between four series of benzo [b][1,x] naphthyridines (x=5-8) have been made. Bromination in acetic acid gave almost exclusive reaction β to the nitrogen in the outer pyrido ring. Basic silver oxide oxidation of the centre ring occurred in the order x = 6 > 8 > 7 > 5. Methylation occurred on the pyrido nitrogen, the relative nucleophilicities paralleling those of the corresponding naphthyridines . One methiodide (x = 6) underwent an interesting dimerization in solution and the structure of the product was determined by X-ray crystallography.