Structure and functioning of intertidal food webs along an avian flyway:A comparative approach using stable isotopes

1. Food webs and trophic dynamics of coastal systems have been the focus of intense research throughout the world, as they prove to be critical in understanding ecosystem processes and functions. However, very few studies have undertaken a quantitative comparison of entire food webs from a key consumer perspective across a broad geographical area, limiting relevant comparisons among systems with distinct biotic and abiotic components.2. We investigate the structure and functioning of food webs in four tidal ecosystems of international importance for migratory shorebirds along the East Atlantic Flyway: Tejo estuary in Portugal, Sidi Moussa in Morocco, Banc d'Arguin in Mauritania and Bijagós archipelago in Guinea-Bissau. Basal food sources, shorebirds and their prey (benthic invertebrates) were sampled in all areas, and Bayesian stable isotope mixing models and community-wide metrics were used in a comparative analysis among areas.3. Significant differences among study areas were found in the structure of food webs, as well as in the relative importance of basal resource pools supporting each food web. Overall, the food web of Banc d'Arguin was characterized by lower trophic diversity and higher functional redundancy than the other sites. This result might be explained by the low number of trophic pathways of organic matter transfer in this seagrass-dominated system which, as a fossil estuary, lacks inputs from both freshwater and nutrient-rich offshore oceanic waters.4. Structure of shorebird communities was consistent with the main organizational patterns found for each food web, highlighting the less diverse character of the community of Banc d'Arguin. At Banc d'Arguin and Bijagós archipelago, which displayed the smallest and largest isotopic niche widths in bird assemblage, respectively, mean niche overlap among species was low, suggesting high interspecific partitioning in resource use. Tropical systems typically offer comparatively lower harvestable prey biomass for shorebirds and might thus strengthen interspecific competition, leading to low niche overlap among species.5. Our study reveals relevant differences in the structure of food webs and shorebird communities in coastal areas along an avian flyway. While differences in trophic redundancy of food webs point to distinct levels of ecosystem resilience, contrasts in the organization of shorebird communities highlight the plasticity in the foraging behaviour of species inhabiting areas with distinct environmental conditions

Overweight and obesity in urban Africa: A problem of the rich or the poor?

BACKGROUND: Obesity is a well recognized risk factor for various chronic diseases such as cardiovascular diseases, hypertension, and type 2 diabetes mellitus. The aim of this study was to shed light on the patterns of overweight and obesity in sub-Saharan Africa, with special interest in differences between the urban poor and the urban non-poor. The specific goals were to describe trends in overweight and obesity among urban women; and examine how these trends vary by education and household wealth. METHODS: The paper used Demographic and Health Surveys data from seven African countries where two surveys had been carried out with an interval of at least 10 years between them. Among the countries studied, the earliest survey took place in 1992 and the latest in 2005. The dependent variable was body mass index coded as: Not overweight/obese; Overweight; Obese. The key covariates were time lapse between the two surveys; woman's education; and household wealth. Control variables included working status, age, marital status, parity, and country. Multivariate ordered logistic regression in the context of the partial proportional odds model was used. RESULTS: Descriptive results showed that the prevalence of urban overweight/obesity increased by nearly 35% during the period covered. The increase was higher among the poorest (+50%) than among the richest (+7%). Importantly, there was an increase of 45-50% among the non-educated and primary-educated women, compared to a drop of 10% among women with secondary education or higher. In the multivariate analysis, the odds ratio of the variable time lapse was 1.05 (p < 0.01), indicating that the prevalence of overweight/obesity increased by about 5% per year on average in the countries in the study. While the rate of change in urban overweight/obesity did not significantly differ between the poor and the rich, it was substantially higher among the non-educated women than among their educated counterparts. CONCLUSION: Overweight and obesity are on the rise in Africa and might take epidemic proportions in the near future. Like several other public health challenges, overweight and obesity should be tackled and prevented early as envisioned in the WHO Global strategy on diet, physical activity and health

Understanding the risk and protective factors associated with obesity amongst Libyan adults - a qualitative study

BACKGROUND: There are a range of multifaceted behavioural and societal factors that combine to contribute to the causes of obesity. However, it is not yet known how particularly countries' cultural norms are contributing to the global obesity epidemic. Despite obesity reaching epidemic proportions in Libya, since the discovery of oil in 1959, there is a lack of information about obesity in Libyan adults. This study sought to explore the views of key informants about the risk and protective factors associated with obesity among Libyan men and women. METHODS: A series of qualitative semi-structured interviews were conducted with Libyan healthcare professionals and community leaders. RESULTS: Eleven main themes (risk and protective factors) were identified, specifically: socio-demographic and biological factors, socioeconomic status, unhealthy eating behaviours, knowledge about obesity, social-cultural influences, Libya's healthcare facilities, physical activity and the effect of the neighbourhood environment, sedentary behaviour, Libyan food-subsidy policy, and suggestions for preventing and controlling obesity. CONCLUSIONS: Key recommendations are that an electronic health information system needs to be implemented and awareness about obesity and its causes and consequences needs to be raised among the public in order to dispel the many myths and misconceptions held by Libyans about obesity. The current political instability within Libya is contributing to a less-active lifestyle for the population due to security concerns and the impact of curfews. Our findings have implications for Libyan health policy and highlight the urgent need for action towards mitigating against the obesity epidemic in Libya

Tumeur stromale jéjunale : à propos de deux cas.

Les tumeurs stromales digestives (TSD) sont rares et représentent entre 1 et 3% de tous les cancers gastro-intestinaux. La grande majorité de ces tumeurs expriment la protéine c-kit. Elles sont révélées le plus souvent par un syndrome obstructif plus rarement par une hémorragie digestive.Il s’agit d’un patient âgé de 56 ans ayant comme antécédent un diabète type 2, hospitalisé pour des réctorragies et des mélénas de moyenne abondance avec un syndrome anémique. L’examen proctologique avait retrouvé des stigmates de saignement récent au delà de 15 cm de la marge anale. L’échographie abdominale avait objectivé une formation kystique au niveau de l’épigastre au contact d’un épaississement digestif. La TDM abdominale avait montré une formation mésentérique au contact d’une anse mesurant 36mm de diamètre. La fibroscopie digestive haute et le lavement baryté n’avaient pas retrouvé d’anomalies.Biologiquement  l’anémie persistait malgré la transfusion sanguine. Devant la persistance de la réctorragie le patient avait bénéficié d’une exploration chirurgicale qui a retrouvé une tumeur au dépend du jéjunum à 20cm de l’angle de Treitz, les anses intestinales et le mésentère correspondant étaient réséqués, emportant la tumeur, avec rétablissement immédiat de la continuité