Environmental forcing and density-dependent controls of Culex pipiens abundance in a temperate climate (Northeastern Italy)

none6siNew and old mosquito-borne diseases have emerged and re-emerged in temperate regions over the recent past, but a mechanistic understanding of mosquito population dynamics, a fundamental step toward disease control, remains elusive. We propose here a Gompertz-based approach to address two obstacles to the development of vector dynamics models in temperate regions: (i) the inclusion of endogenous processes (e.g. density limitation, delayed responses, etc.) and the evaluation of their relative importance vs. exogenous environmental forcings; (ii) the inclusion of realistic descriptions of hydrologic processes and the evaluation of soil moisture as a more direct driver of mosquito population dynamics. The new model is based on a hierarchical state-space structure and is applied to the description of the abundance of Culex pipiens - a West Nile Virus vector - in the Po River Delta region (Northeastern Italy), using weekly mosquito abundance observations at more than 20 sites in the period May-September in 2010 and 2011. The hierarchical structure provides an efficient way of fully exploiting the information from a large network of observation sites. We find that Cx. pipiens abundance has significant density dependence at the one-week scale, which is coherent with its larval developmental time during the summer. This result points to the importance of endogenous population dynamics, most often neglected in mosquito population models, usually simply driven by exogenous environmental forcings. Among exogenous controls, temperature, daylight hours, and soil moisture were found to be most influential. Use of precipitation or soil moisture to force the model leads to very similar predictive skills. The negative correlation of soil moisture and mosquito population may be attributed to the abundance of water in the region (e.g. due to irrigation) and the preference for eutrophic habitats by Cx. pipiens. Variations among sites were highly correlated with land-use factors. The carrying capacity is seen to decrease with the distance to the nearest rice field, while the maximum population growth rate was positively related with the Normalized Difference Vegetation Index, a proxy of vegetation cover. The model shows a satisfactory performance in explaining the variation of mosquito abundance over a horizon of 1 week, particularly as far as peak timing and magnitude are concerned. Large rates of change of population abundance remain difficult to predict, as in other existing models, pointing to persisting gaps in our understanding of the mechanisms regulating mosquito population dynamics. © 2013 Elsevier B.V.noneJian Y.; Silvestri S.; Belluco E.; Saltarin A.; Chillemi G.; Marani M.Jian Y.; Silvestri S.; Belluco E.; Saltarin A.; Chillemi G.; Marani M

Haemorheological parameters in alopecia areata

none5noneCIPRIANI R; PROCIDANO M; SALTARIN P; GIROLAMI A; A. PESERICO STECCHINI NEGRI DE SALVICipriani, R; Procidano, M; Saltarin, P; Girolami, A; PESERICO STECCHINI NEGRI DE SALVI, Andre

Sociological interpretation of hippies movement

My bachelor thesis explores the hippie movement, which emerged in the middle of the sixties in the United States of America. The theoretical framework consists of sociological concepts of culture, subculture, youth and youth subcultures, communities, communes and social movements. The hippie movement was young people's response to middle class consumerism, which preferred material prosperity to moral and cultural values. The American transcendentalist movement and the Beat Generation can be considered its intellectual precursor. The movement's main characteristic was rejection of middle class values. Therefore, some authors have called it a counterculture. Hippies gave up studies and tangible assets. Typical for them was lack of confidence in the future, interest in oriental philosophy and religion, close relationship to nature, specific clothing style, living in communes and the use of drugs, especially LSD. The movement dissipated at the end of the sixties. Its influence is still evident in the effort to fight for human rights, peace, free network, but also in music and clothing. Some of the hippie movement's ideas are the source of today's youth subcultures and movements. Key words: social movement, youth, community, hippies, LS

Additional file 3: Table S2. of High genetic diversity in the Culex pipiens complex from a West Nile Virus epidemic area in Southern Europe

Summary of Culex pipiens complex samples analyzed with reference to individual haplotypes. (DOCX 50 kb

High genetic diversity in the Culex pipiens complex from a West Nile Virus epidemic area in Southern Europe

Background The Culex pipiens complex includes the most widespread mosquito species in the world. Cx. pipiens is the primary vector of the West Nile Virus (WNV) in Europe and North America. Cases of WNV have been recorded in Italy since 1998. In particular, wet areas along the Po River are considered some of the most WNV affected areas in Italy. Here, we analyzed the genetic structure of ten Cx. pipiens populations collected in the last part of the Po River including the Delta area. Methods We assessed the genetic variability of two mitochondrial markers, cytochrome oxidase 1 (COI) and 2 (COII), for a total of 1200 bp, and one nuclear marker, a fragment of acetylcholinesterase-2 (ace-2), 502 bp long. The effect of the landscape features was evaluated comparing haplotype and nucleotide diversity with the landscape composition. Results The analysis showed a high genetic diversity in both COI and COII gene fragments mainly shared by the populations in the Delta area. The COI-COII network showed that the set of haplotypes found was grouped into three main supported lineages with the higher genetic variability gathered in two of the three lineages. By contrast, ace-2 fragment did not show the same differentiation, displaying alleles grouped in a single clade. Finally, a positive correlation between mitochondrial diversity and natural wetland areas was found. Conclusions The high mitochondrial genetic diversity found in Cx. pipiens populations from the Po River Delta contrasts with the low variability of inland populations. The different patterns of genetic diversity found comparing mitochondrial and nuclear markers could be explained by factors such as differences in effective population size between markers, sex biased dispersal or lower fitness of dispersing females. Moreover, the correlation between genetic diversity and wetland areas is consistent with ecosystem stability and lack of insecticide pressure characteristic of this habitat. The mtDNA polymorphism found in the Po River Delta is even more interesting due to possible linkages between the mitochondrial lineages and different biting behaviors of the mosquitoes influencing their vector ability of arboviral infections