Epidemiology of asexuality induced by the endosymbiotic Wolbachia across phytophagous wasp species: host plant specialization matters.

Among eukaryotes, sexual reproduction is by far the most predominant mode of reproduction. However, some systems maintaining sexuality appear particularly labile and raise intriguing questions on the evolutionary routes to asexuality. Thelytokous parthenogenesis is a form of spontaneous loss of sexuality leading to strong distortion of sex ratio towards females and resulting from mutation, hybridization or infection by bacterial endosymbionts. We investigated whether ecological specialization is a likely mechanism of spread of thelytoky within insect communities. Focusing on the highly specialized genus Megastigmus (Hymenoptera: Torymidae), we first performed a large literature survey to examine the distribution of thelytoky in these wasps across their respective obligate host plant families. Second, we tested for thelytoky caused by endosymbionts by screening in 15 arrhenotokous and 10 thelytokous species for Wolbachia, Cardinium, Arsenophonus and Rickettsia endosymbionts and by performing antibiotic treatments. Finally, we performed phylogenetic reconstructions using multilocus sequence typing (MLST) to examine the evolution of endosymbiont-mediated thelytoky in Megastigmus and its possible connections to host plant specialization. We demonstrate that thelytoky evolved from ancestral arrhenotoky through the horizontal transmission and the fixation of the parthenogenesis-inducing Wolbachia. We find that ecological specialization in Wolbachia's hosts was probably a critical driving force for Wolbachia infection and spread of thelytoky, but also a constraint. Our work further reinforces the hypothesis that community structure of insects is a major driver of the epidemiology of endosymbionts and that competitive interactions among closely related species may facilitate their horizontal transmission.

[Eating behaviour and body image in a sample of adolescents from Sevilla]. / Conducta alimentaria e imagen corporal en una muestra de adolescentes de Sevilla.

OBJECTIVE: This study examined the presence of disordered eating behaviours and the influence that on them could have the degree of body dissatisfaction among adolescents. METHOD: By the Eating Attitudes Test-40 (EAT-40), the Sick Control On Fat Food (SCOFF) and the subscale of body dissatisfaction (BD) of the Eating Disorders Inventory-2 (EDI-2) a total of 841 students, aged 12-19, were studied. Eating behaviours, sex and age differences, and eating attitudes and behaviours related to the degree of body dissatisfaction were analized. RESULTS: We found that 21,29% had significant punctuations in the SCOFF and 7,13% in the EAT-40. There were significant sex-differences (13,93% and 3,23% in SCOFF and EAT-40 for males, 29,38% and 10,70% for women). With regard to previous studies, a decrease of the risk is observed in women and an increase in males. Major body dissatisfaction was observed among the 12 to 17-year-old girls, though sex-differences in eating alterations, can be mostly found between the ages of 14 and 16. Body dissatisfaction correlated positively and significantly to Body Mass Index, EAT-40 and SCOFF. CONCLUSION: In order to implement primary programs in the adolescent population it is necessary to explore the eating behaviours of risky and the degree of body dissatisfaction to be able to raise specifically the interventions to be carried out, involving teachers as primary agents for the work in the school context.

Conducta alimentaria e imagen corporal en una muestra de adolescentes de Sevilla / Eating behaviour and body image in a sample of adolescents from Sevilla

Objetivo: En el presente trabajo se analiza la presencia de alteraciones alimentarias y la influencia que sobre ellas puede tener el grado de insatisfacción corporal entre los adolescentes. Método: Aplicando el Eating Attitudes Test-40 (EAT-40), el Sick Control On Fat Food (SCOFF) y la subescala de insatisfacción corporal (BD) del Eating Disorders Inventory-2 (EDI-2) a 841 estudiantes, de 12 a 19 años, se analizaron las conductas alimentarias de riesgo, se estudiaron las diferencias en función del sexo y la edad y se analizó la relación de dichas conductas con el grado de insatisfacción corporal. Resultados y discusión: El 21,29% tuvo puntuaciones significativas en el SCOFF y el 7,13% en el EAT-40. Por sexos, hubo diferencias significativas (13,93% y 3,23% en SCOFF y EAT-40 para los varones, 29,38% y 10,70% para las mujeres). Con respecto a datos anteriores, se observa un descenso del riesgo en las mujeres y un incremento en los varones. Se observó una mayor insatisfacción corporal en las chicas de 12 a 17 años, si bien la diferencia entre chicas y chicos, en alteraciones alimentarias, se centra en los 14-16 años. La insatisfacción corporal correlacionó positiva y significativamente con el Índice de Masa Corporal, EAT-40 y SCOFF. Para implantar programas de prevención primaria en la población adolescente, es necesario conocer las conductas alimentarias de riesgo y el grado de insatisfacción corporal, para poder plantear específicamente las intervenciones a llevar a cabo, involucrando al profesorado como agente primario de trabajo en el contexto escolar (AU)

Objective: This study examined the presence of disordered eating behaviours and the influence that on them could have the degree of body dissatisfaction among adolescents. Method: By the Eating Attitudes Test-40 (EAT-40), the Sick Control On Fat Food (SCOFF) and the subscale of body dissatisfaction (BD) of the Eating Disorders Inventory-2 (EDI-2) a total of 841 students, aged 12-19, were studied. Eating behaviours, sex and age differences, and eating attitudes and behaviours related to the degree of body dissatisfaction were analized. Results: We found that 21,29% had significant punctuations in the SCOFF and 7,13% in the EAT-40. There were significant sex-differences (13,93% and 3,23% in SCOFF and EAT-40 for males, 29,38% and 10,70% for women). With regard to previous studies, a decrease of the risk is observed in women and an increase in males. Major body dissatisfaction was observed among the 12 to 17-year-old girls, though sex-differences in eating alterations, can be mostly found between the ages of 14 and 16. Body dissatisfaction correlated positively and significantly to Body Mass Index, EAT-40 and SCOFF. Conclusion: In order to implement primary programs in the adolescent population it is necessary to explore the eating behaviours of risky and the degree of body dissatisfaction to be able to raise specifically the interventions to be carried out, involving teachers as primary agents for the work in the school context (AU)

The olfactory experience: constants and cultural variables.

Odor and olfaction anthropology explores four lines of research which, in many cases, may overlap: the variability of the olfactory perception, olfactory skills and know-how, odor use, and odor representations. My proposal here is to deal with the first one, trying to answer the following question: is olfactory perception a phenomenon resulting solely from the biological organization of the human being, in such a way that it does not know other variations than the ones due to nature? Or, on the contrary, can we show different kinds of olfaction culturally determined or, at least, environmental influences resulting in significant perceptual differences among groups, societies, cultures, etc.? In the first part of the text, I will deal with the invariants (or universals). In the second, I will insist on the cultural types of olfaction. In the third and last part, I will advance the following proposal: beyond the discussion on the roles that nature and culture play in human olfaction, we can sustain that naturally and culturally, there is a way of smelling characteristic of our species. Finally, I will conclude with two examples of the symbolic treatment characteristic of the olfactory human experience.