Genetic Structure of the Tiger Mosquito, Aedes albopictus, in Cameroon (Central Africa)

Background: Aedes albopictus (Skuse, 1884) (Diptera: Culicidae), a mosquito native to Asia, has recently invaded all five continents. In Central Africa it was first reported in the early 2000s, and has since been implicated in the emergence of arboviruses such as dengue and chikungunya in this region. Recent genetic studies of invasive species have shown that multiple introductions are a key factor for successful expansion in new areas. As a result, phenotypic characters such as vector competence and insecticide susceptibility may vary within invasive pest species, potentially affecting vector efficiency and pest management. Here we assessed the genetic variability and population genetics of Ae. albopictus isolates in Cameroon (Central Africa), thereby deducing their likely geographic origin. Methods and Results: Mosquitoes were sampled in 2007 in 12 localities in southern Cameroon and analyzed for polymorphism at six microsatellite loci and in two mitochondrial DNA regions (ND5 and COI). All the microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structureamong geographic populations (F-ST = 0.068, P<0.0001). Analysis of mtDNA sequences revealed four haplotypes each for the COI and ND5 genes, with a dominant haplotype shared by all Cameroonian samples. The weak genetic variation estimated from the mtDNA genes is consistent with the recent arrival of Ae. albopictus in Cameroon. Phylogeographic analysis based on COI polymorphism indicated that Ae. albopictus populations from Cameroon are related to tropical rather than temperate or subtropical outgroups. Conclusion: The moderate genetic diversity observed among Cameroonian Ae. albopictus isolates is in keeping with recent introduction and spread in this country. The genetic structure of natural populations points to multiple introductions from tropical regions

Barcelona, ¿ciudad del miedo?: urbanismo preventivo y control del espacio público

Peer Reviewe

La responsabilidad del estado por falla del servicio público

Tesis (Abogado) -- Universidad de Cartagena. Facultad de Derecho y Ciencias Políticas. Programa de Derecho, 1973Con la expedición del decreto 528 de 1964 de la reforma judicial, que establece que los negocios relativos a la responsabilidad del estado se trasladen de la competencia de la justicia ordinaria a la de lo contencioso-administrativo

Prebiotic effects of inulin extracted from burdock (Arctium lappa) in broilers

ABSTRACT: The aim of this study was to evaluate the prebiotic effect of burdock (Arctium lappa) in commercial poultry. Four experiments were conducted to evaluate the performance parameters and the protection after challenge with Salmonella Enteritidis and Salmonella Kedougou, with and without Bifidobacterium probiotic. In two trials, the chickens were fed with flour burdock 1% during 42 days. In the other two, the chickens were fed with fructan extracted from burdock (inulin), by gavage, at a concentration of 100 mg/bird, during the first three days of life. The results showed that the broilers treated with burdock flour showed underperformed, with less weight gain from the second week, and the worst results in the fattening stage. The treated birds had diarrhea and impaired intestinal integrity. However, the groups treated with the flour had a lower rate of intestinal colonization by Salmonella Kedougou, after challenge. No statistically significant differences were detected in the performance parameters of broilers receiving the inulin, and the morphometric analysis showed no lesions in the intestinal villi. However, there was no protection in the challenge with Salmonella Enteritidis, regardless of association with probiotic. These results demonstrated that the manner of administration has influence on the prebiotic effect of burdock. The burdock flour was administered for 42 days, which may have influenced intestinal mucosal injury. Instead, the inulin was given only in the first three days, which may have been insufficient for protection against Salmonella. New experiments are needed to determine an able formulation for a protective effect, without negative impact on growth, weight gain and feed conversion of the supplemented animals