2 research outputs found
Extracellular vesicles from seminal plasma to improve fertilizing capacity of bulls
No full textSeminal plasma contains extracellular vesicles (EVs) that vehicle RNA, proteins, and other molecules able to influence the biological function of sperm. The aim of this study was to improve the fertilizing capacity of male gametes of low-fertility bulls using EVs isolated by ultracentrifugation from the seminal plasma of a bull of proven fertility. After dose-response curve, 10×106 sperm of low-fertility bulls were co-incubated for an hour with 400×106 EVs/ml. In addition, it has been verified that the incorporation of EVs, which takes place in the sperm midpiece, is maintained for 5 hours and even after cryopreservation. Subsequently, the spermatozoa of low-fertility bulls, with EVs incorporated, were used for the in vitro production of embryos. The rate of blastocyst at seventh day yield in vitro, with the use of sperm with EVs incorporated, increased by about twice the yield obtained with the same sperm in the absence of EVs: bulls having an average embryonic yield of 6.41±1.48%, 10.32±4.34% and 10.92±0.95% improved their yield to 21.21±1.99%, 22.17±6.09% and 19.99±5.78%, respectively (P<0.05). These encouraging results suggest that it might be possible to keep breeding bulls with poor fertility. Further studies will be needed to evaluate the in vivo fertility of sperm treated with EVs and understand how the content of EVs is involve in the sperm-vesicle interaction and in the improved sperm performance
O relato de viagem e seu narrador: análise de Diário de uma Viagem ao Brasil (1821-1823), de Maria Graham
No full textO presente trabalho tem como objetivo estudar o narrador do livro Diário de Uma Viagem ao Brasil, da inglesa Maria Graham, problematizando como este organiza em forma narrativa o olhar lançado sobre o Brasil em 1821. Foi feita uma delimitação do gênero do relato de viagem conforme entendido por Tzvetan Todorov. Em seguida, estudou-se a metodologia da análise da narrativa a partir das proposições de Walter Benjamin, de teóricos estruturalistas e de Yves Reuter – as ideias deste último foram empregadas na análise. Foram discutidas as observações a respeito do impacto do relato de viagem na constituição de uma noção de “brasileiro”. Também buscou-se esclarecer o contexto histórico e de produção editorial do período de produção. Finalmente, analisou-se fragmentos do livro, particularmente o relato do período de 21 de setembro e 9 de dezembro de 1821. Nos resultados da análise, verificou-se semelhança do olhar da narradora com o olhar do naturalista, bem como a tendência de descrever a paisagem e os nativos a partir de critérios europeus, sem relativizá-los. Além disso, detectou-se a ocorrência de elementos da representação encadeados em um discurso e a presença extensiva da função explicativa ao longo de todo o texto.This work seeks to study the narrator in the book Diary of a Voyage to Brazil, by british author Maria Graham, questioning the way she organizes the narrative form from their perspective upon Brazilian lands in the year of 1821. We described the literary genre of travel narratives as it is understood by Tzvetan Todorov. Then, we studied the methodology of analysis of narrative, as seen by Walter Benjamin, some structuralist theorists and Yves Reuter – the last one whose ideas were used for the analysis. Besides that, we discussed some writings about the influence that travel narratives had on the constitution of “Brazilian” as an idea. We also tried to explain the historical context and the editorial production during the early 1800s. Finally, we analysed some fragments from the book, specifically the diary entries written between september 21st and december 9th, 1821. We found out that the book’s narrator was simillar to that of the naturalists that traveled around Brazil at the time, and she also showed a propensity for describing the landscape and the people from the country based on European criteria, without any attempt of relativization. The presence of some representation elements in the structure of a discourse, as well as the extensive presence of explanative function all over the text was also detected
