246 research outputs found

    Lixiviação e volatilização de nitrogênio em um Argissolo cultivado com videira submetida à adubação nitrogenada.

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    O nitrogênio (N) aplicado na superfície do solo em vinhedos pode ser perdido por volatilização ou lixiviação, sendo uma das possíveis explicações para o baixo aproveitamento de N pelas videiras. O trabalho objetivou avaliar as perdas de N por volatilização e lixiviação do N mineral em solo cultivado com videira submetida à adubação nitrogenada. Foram instalados dois experimentos em um vinhedo de Cabernet Sauvignon, em Rosário do Sul (RS), Brasil. No experimento 1, foram instalados lisímetros no solo que recebeu a aplicação de 0, 40, 80 e 120kg de N ha-1 ano-1 na forma de ureia e, durante o período de agosto a dezembro de 2009, foi coletada a solução do solo para a análise de N mineral. No experimento 2, foram instaladas câmaras coletoras no solo que recebeu, em agosto de 2010, a aplicação de 0, 20, 40, e 80kg de N ha-1 ano-1 na forma de ureia, 40kg de N ha-1 ano-1 de composto orgânico e 40kg de N ha-1 ano-1 de ureia revestida com polímeros, para avaliar a volatilização de N-NH3 do momento da aplicação até 80 horas depois da aplicação. As maiores concentrações de nitrogênio mineral na solução lixiviada foram encontradas nas doses mais elevadas de fertilizante mineral aplicado e ao longo da brotação e florescimento das videiras, o que pode diminuir o aproveitamento do nutriente pelas plantas. Os maiores fluxos e perdas de amônia do solo cultivado com videira para a atmosfera aconteceram nas doses mais elevadas de nitrogênio mineral aplicado, especialmente, depois de 44 horas da sua aplicação sobre a superfície do solo. A aplicação de ureia revestida com polímeros e composto orgânico promoveram as menores perdas de amônia por volatilização, o que pode estimular o aproveitamento de nitrogênio pelas videiras

    Servicio de referencia, fuentes de información y desarrollo de colecciones: una propuesta de formación integral

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    This work presents a proposal for comprehensive training of the curricular units Reference Service, Specialized Information Sources, Collections’ development and Information Literacy in the Bachelor's Degree in Library Science of the Faculty of Information and Communication. There are several meeting points among these subjects, sometimes identifying cyclical or linking relationships depending on the topic being addressed. Possible synergies included are the reference service and its collection of specialized sources; the management of specialized collections in an area of knowledge; the close link between information literacy and the reference service as a framework for its development. Based on the identification of these links, it is proposed a methodology applied to university teaching of the bachelor’s degree in library science, which allows an integrated formation of the contents. It is expected that this methodology will result in a better understanding of the topics for the student body, obtaining a comprehensive training on the topics

    The Latin American Dialysis and Renal Transplantation Registry: report 2019

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    Background Chronic kidney disease (CKD) in Latin America (LA) continues to represent a challenge due to the burden of disease it causes and the difficulty in accessing treatment. LA has a total population of 652 million people living in 20 countries that occupy an area of 19.2 million km2. The Latin American Dialysis and Renal Transplantation Registry (LADRTR), founded in 1991, has collected data and reports on patients receiving kidney replacement therapy (KRT) since 1993. This article summarizes the registry data for 2019. Methods Participating countries complete an annual survey collecting aggregated data on incident and prevalent patients on KRT in all modalities. The different treatment modalities considered were hemodialysis (HD), peritoneal dialysis (PD) and living functioning kidney graft (LFG). National gross domestic product per capita (GDP, expressed in US dollars) and life expectancy at birth (LEB) corresponding to the year 2019 were collected from the World Bank Data Bank. Prevalence and incidence were compared with previous years and were also correlated with GDP and LEB. Results On 31 December 2019 a total of 432 610 patients were in KRT in LA, corresponding to an overall unadjusted prevalence of 866 per million population (pmp). Regarding treatment modality, 66.7% of the prevalent patients were treated with HD and 9.3% with PD while 24% of the patients had an LFG. A total of 85 224 patients started KRT in LA, representing a total unadjusted incidence rate of 168 pmp. Diabetic nephropathy as a cause of CKD continues to be a relevant percentage (36%) and five countries reported CKD of nontraditional causes. The kidney transplant rate in the region was 22 pmp, varying from 1 to >60 pmp. The total prevalence of KRT correlated positively with GDP per capita (r2 = 0.6, P < 0.01) and LEB (r2 = 0.23, P < 0.05). The overall incidence rate also significantly correlated with GDP (r2 = 0.307, P < 0.05). The overall unadjusted mortality rate was 13%. Conclusion Accessibility to KRT is still limited in LA. It is necessary to continue the efforts made by each country and the Latin American Society of Nephrology and Hypertension to guarantee equal access to treatment

    Increased Oxidative Stress and Imbalance in Antioxidant Enzymes in the Brains of Alloxan-Induced Diabetic Rats

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    Diabetes Mellitus (DM) is associated with pathological changes in the central nervous system (SNC) as well as alterations in oxidative stress. Thus, the main objective of this study was to evaluate the effects of the animal model of diabetes induced by alloxan on memory and oxidative stress. Diabetes was induced in Wistar rats by using a single injection of alloxan (150 mg/kg), and fifteen days after induction, the rats memory was evaluated through the use of the object recognition task. The oxidative stress parameters and the activity of antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT) were measured in the rat brain. The results showed that diabetic rats did not have alterations in their recognition memory. However, the results did show that diabetic rats had increases in the levels of superoxide in the prefrontal cortex, and in thiobarbituric acid reactive species (TBARS) production in the prefrontal cortex and in the amygdala in submitochondrial particles. Also, there was an increase in protein oxidation in the hippocampus and striatum, and in TBARS oxidation in the striatum and amygdala. The SOD activity was decreased in diabetic rats in the striatum and amygdala. However, the CAT activity was increased in the hippocampus taken from diabetic rats. In conclusion, our findings illustrate that the animal model of diabetes induced by alloxan did not cause alterations in the animals' recognition memory, but it produced oxidants and an imbalance between SOD and CAT activities, which could contribute to the pathophysiology of diabetes

    Predicting soybean development with a simple photothermal dynamic algorithm

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    Predicting the occurrence of the critical period for soybean’s yield determination is important for farmers to decide on variety and sowing date with the objective to expose this period (during which yield is mainly determined) to the best environmental conditionsEEA PergaminoFil: Severini, Alan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Sección Ecofisiología; ArgentinaFil: Álvarez Prado, S. Universidad de Buenos Aires, Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Otegui, María Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Ecofisiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Vega, Claudia Rosa Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Zuil, Sebastian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Reconquista; ArgentinaFil: Kavanová, M. Instituto Nacional de Investigación Agropecuaria (INIA). La Estanzuela; UruguayFil: Ceretta, S. Instituto Nacional de Investigación Agropecuaria (INIA). La Estanzuela; UruguayFil: Acreche, Martin Moises. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scholz Drodowski, R.F. Instituto Paraguayo de Tecnología Agraria (IPTA). Capitan Miranda; ParaguayFil: Serrago, R.A. Universidad de Buenos Aires, Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miralles, D.J. Universidad de Buenos Aires, Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Nitrogen fertilization of "Chardonnay" grapevines: yield, must composition and their relationship with temperature and rainfall.

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    In soils rich inorganic matter(OM), such as those in the elevations of South Brazil, themineralized N from organic matter does not always meet the N demands of grapevines, thus, N applications are necessary during vinegrowth. However, the optimal N rate to achieve satisfactory yield and desirable grape enological composition is not known

    Adubação de pré-plantio e crescimento em videiras

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    Calagem, adubação e contaminação em solos cultivados com videiras Resumo -O rápido crescimento de videiras jovens e o início da produção é dependente da adubação de pré-plantio e crescimento. Assim, no presente capítulo são apresentadas informações referentes à calagem e tipos de adubações, especialmente de pré- plantio, realizada antes da implantação do vinhedo, e de crescimento, fase posterior ao transplante até o início da produção de uva. São apresentados os critérios para a tomada de decisão da necessidade e doses de fertilizantes, modos de aplicação e fontes e nutrientes. Além disso, são relatados resultados de pesquisa obtidos nas condições edafoclimáticas da região Sul do Brasil. Palavras-chave:calagem, adubação de plantio, adubação de crescimento, análise de solo, vinhedo.bitstream/item/156809/1/Adubacao-de-pre-plantio-e-crescimento-em-videiras.pd
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