Caracterização dos solos do município de Belterra, Estado do Pará.

bitstream/item/63490/1/Oriental-Doc88.pdfAnexo mapa: Mapa de solos do Município de Belterra - Pará

Regulation Of Immune Cell Function By Short-chain Fatty Acids

Short-chain fatty acids (SCFAs) are bacterial fermentation products, which are chemically composed by a carboxylic acid moiety and a small hydrocarbon chain. Among them, acetic, propionic and butyric acids are the most studied, presenting, respectively, two, three and four carbons in their chemical structure. These metabolites are found in high concentrations in the intestinal tract, from where they are uptaken by intestinal epithelial cells (IECs). The SCFAs are partially used as a source of ATP by these cells. In addition, these molecules act as a link between the microbiota and the immune system by modulating different aspects of IECs and leukocytes development, survival and function through activation of G protein coupled receptors (FFAR2, FFAR3, GPR109a and Olfr78) and by modulation of the activity of enzymes and transcription factors including the histone acetyltransferase and deacetylase and the hypoxia-inducible factor. Considering that, it is not a surprise, the fact that these molecules and/or their targets are suggested to have an important role in the maintenance of intestinal homeostasis and that changes in components of this system are associated with pathological conditions including inflammatory bowel disease, obesity and others. The aim of this review is to present a clear and updated description of the effects of the SCFAs derived from bacteria on host immune system, as well as the molecular mechanisms involved on them.

Evolutionary processes underlying latitudinal differences in reef fish biodiversity

Aim: To examine the dynamics among the processes of speciation, extinction and dispersal in marine environments using phylogenies to reveal the evolutionary mechanisms that promote latitudinal differences in biodiversity. Using phylogenetic comparative methods we assess whether tropical reef fish lineages show higher diversification rates and whether the majority of extratropical reef fish lineages have originated from tropical areas. Location: Shallow water tropical and extratropical reefs globally. Methods: Using fossil-calibrated phylogenies for four reef-associated fish families (Chaetodontidae, Labridae, Pomacentridae and Sparidae) we apply evolutionary models (GeoSSE and HiSSE) that allow the estimation of speciation, extinction and dispersal rates associated with geographical ranges and explore potential biases from unsampled characters. Results: We found that tropical lineages show higher rates of speciation and tended to have lower extinction rates. Overall, we identify higher net diversification rates for tropical lineages compared with those in extratropical regions in all four families. Rates of dispersal tended to be higher for lineages with tropical origins expanding into extratropical regions. Within the family Labridae, two tropical lineages were found to exhibit higher net diversification rates, above that expected from latitudinal differences. Main conclusions : Our results offer support for the predictions of the out of the tropics' and evolutionary speed' models of evolution, both of which highlight the marine tropics as an important evolutionary engine promoting latitudinal differences in reef fish biodiversity. Moreover, we find that two tropical labrid lineages are undergoing exceptional diversification associated with additional traits, possibly linked with the extreme sexual dichromatism observed in both clades

Variabilidade fenotípica para teor de ácido pirúvico em populações de cebola suave no Vale do São Francisco.

Suplemento. Trabalho apresentado no 49. Congresso Brasileiro de Olericultura, Águas de Lindóia, SP

Tamanho da semente de guaraná e sua influência na emergência e no vigor.

bitstream/item/33547/1/CPATU-CirTec20.pd

Avaliação de cultivares de milho no município de Paragominas - Pará.

bitstream/item/57743/1/CPATU-ComTec94.pd

Dinâmica do nitrogênio em função da aplicação de lodos de esgoto em sistema de plantio direto.

Projeto/Plano de Ação: 01.09.10103-04