The South American continent is composed of several biogeographical regions harbouring the highest biodiversity on the globe, encompassing five of the world's biodiversity 'hot spots'. Nonetheless,… (More)
The roles of intra- and interspecific gene flow in speciation and species evolution are topics of great current interest in molecular ecology and evolutionary biology. Recent modelling studies call… (More)
Two immunohistochemical techniques to determine the presence of yellow fever and dengue antigens in fixed tissue samples were developed for the purpose of making retrospective diagnoses of these… (More)
The aim of this study was to evaluate the resistance to ten antimicrobial agents and the presence of bla TEM1 gene of Gram-negative bacteria isolated from three natural oligotrophic lakes with… (More)
We report the potential risk for an infectious disease through tainted transfusion in 10 countries of South and Central America in 1993 and in two countries of South America in 1994, as well as the… (More)
Epidendrum fulgens has a patchy distribution along the Atlantic Rainforest in the Brazilian coast, due to the destruction of its native habitat. Here, we report on both the development of nine new… (More)
In the last 15 years, dengue fever has emerged as a major health problem in tropical America. Prevention and control of epidemic disease are enhanced by the rapid identification of new or increased… (More)
Hantaviruses and arenaviruses are naturally occurring viruses of rodents. Four South American hemorrhagic fevers caused by arenaviruses have emerged in the last 5 decades. All have similar clinical… (More)
The energy transport velocity v(E) and the diffusion constant D of electromagnetic waves in the presence of randomly distributed ferromagnetic scatterers are studied. v(E) presents a strong… (More)