Universidade Federal de Minas Gerais

About: Universidade Federal de Minas Gerais is a education organization based out in Belo Horizonte, Minas Gerais, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 41631 authors who have published 75688 publications receiving 1249905 citations.

Amazon plant diversity revealed by a taxonomically verified species list

Abstract: Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.

Watch me playing, i am a professional: a first study on video game live streaming

Abstract: "Electronic-sport" (E-Sport) is now established as a new entertainment genre. More and more players enjoy streaming their games, which attract even more viewers. In fact, in a recent social study, casual players were found to prefer watching professional gamers rather than playing the game themselves. Within this context, advertising provides a significant source of revenue to the professional players, the casters (displaying other people's games) and the game streaming platforms. For this paper, we crawled, during more than 100 days, the most popular among such specialized platforms: Twitch.tv. Thanks to these gigabytes of data, we propose a first characterization of a new Web community, and we show, among other results, that the number of viewers of a streaming session evolves in a predictable way, that audience peaks of a game are explainable and that a Condorcet method can be used to sensibly rank the streamers by popularity. Last but not least, we hope that this paper will bring to light the study of E-Sport and its growing community. They indeed deserve the attention of industrial partners (for the large amount of money involved) and researchers (for interesting problems in social network dynamics, personalized recommendation, sentiment analysis, etc.).

Raman Spectroscopy of Carbon Nanotubes in 1997 and 2007

Abstract: Over the last 10 years, carbon nanotubes have offered a unique system for the study of Raman spectra in one-dimensional systems, and at the same time Raman spectroscopy has provided a widely used and powerful tool for the characterization of single walled carbon nanotubes (SWNTs). The 10 year history of Raman scattering in SWNTs is reviewed here and future prospects for the field are discussed.

Characterization of inflammatory infiltrates in chronic chagasic myocardial lesions : presence of tumor necrosis factor-α+ cells and dominance of granzyme A+, CD8+ lymphocytes

Abstract: The inflammatory infiltrates in the heart lesions of chronic chagasic cardiomyopathy are composed predominantly of small lymphocytes with admixed macrophages, plasma cells, and segmented leukocytes. The phenotypes of the lymphoid cells in these infiltrates of human Chagas' disease have not been previously detailed. We used a panel of monoclonal and polyclonal antibodies to immunohistochemically characterize the inflammatory cells in frozen and fixed cardiac tissues from autopsied patients with severe chronic chagasic cardiomyopathy. In all cases, the inflammatory lesions were dominated by CD8+ lymphocytes, many of which expressed granzyme A. A few macrophage-like cells that expressed tumor necrosis factor-alpha were observed in each case. Relatively few natural killer cells or B lymphocytes were found in the lesions. These findings in human chagasic lesions are compatible with concepts that involve cytolysis and fibrosis, and new experimental findings that emphasize potential roles for CD8+ T cells in Chagas' disease.