Convergence characteristics between a rodent, the South American lowland paca, and a ruminant, the African water chevrotain: An exemplary case study.

The level of convergence between a rodent, the South American lowland paca Cuniculus paca, and a ruminant, the African water chevrotain Hyemoschus aquaticus, is analysed using 231 characteristics belonging to different biological sectors. A convergence index is established based on the degree of rarity of each characteristic in each species compared to other members of its zoological group. Although the divergent characteristics are as numerous as the convergent ones, the two species are globally similar.

Seasonal Reproduction in Neotropical Rainforest Mammals.

Seasonal changes in tropical forests have been documented in dry and semi-deciduous forests, but not in evergreen ones. Owing to its high level of annual rainfall, French Guiana is considered to be a rainy region, despite a pronounced dry season. French Guiana is therefore appropriate for studying the impact of the dry season on the phenology of rainforest animals.

Sexual dimorphism across 3 stages of development in polygynous Artiodactyls is not affected by maternal care.

In polygynous mammals, mature males are usually much heavier than females. Competition for females is intense, and few males reproduce. Given the importance of the male's body size for the reproduction and social life of these species, levels of sexual dimorphism were studied in 27 species of polygynous terrestrial cetartiodactyls at the 3 most significant stages of development: birth, 6 months of age, and adulthood.

Histology of genital tract and breast tissue after long-term testosterone administration in a female-to-male transsexual population.

Growing evidence indicates that androgens play a positive role in follicle proliferation and growth. Hence, many authors have assumed that androgen supplementation in women with poor ovarian reserve might improve the number of antral follicles available for ovarian stimulation. As androgen administration may become more frequently used in reproductive medicine, this study aimed at describing the histological changes observed in the genital tract and the breast of female-to-male (FTM) transsexuals.

An ex-vivo human intestinal model to study Entamoeba histolytica pathogenesis.

Amoebiasis (a human intestinal infection affecting 50 million people every year) is caused by the protozoan parasite Entamoeba histolytica. To study the molecular mechanisms underlying human colon invasion by E. histolytica, we have set up an ex vivo human colon model to study the early steps in amoebiasis.