Resumen multidocumento utilizando teorías semántico-discursivas

El resumen automático tiene por objetivo reducir el tamaño de los textos, preservando el contenido más importante. En este trabajo, proponemos algunos métodos de resumen basados en dos teorías semántico-discursivas: Teoría de la Estructura Retórica (Rhetorical Structure Theory, RST) y Teoría de la Estructura Inter-Documento (Cross-document Structure Theory, CST). Han sido elegidas ambas teorías con el fin de abordar de un modo más relevante de un texto, los fenómenos relacionales de inter-documentos y la distribución de subtopicos en los textos. Los resultados muestran que el uso de informaciones semánticas y discursivas para la selección de contenidos mejora la capacidad informativa de los resúmenes automáticos.Automatic multi-document summarization aims at reducing the size of texts while preserving the important content. In this paper, we propose some methods for automatic summarization based on two semantic discourse models: Rhetorical Structure Theory (RST) and Cross-document Structure Theory (CST). These models are chosen in order to properly address the relevance of information, multi-document phenomena and subtopical distribution in the source texts. The results show that using semantic discourse knowledge for content selection improve the informativeness of automatic summaries

Brasil y sus intereses en la construcción de Cachuela Esperanza, Bolivia

La necesidad de energía obliga a los países a reflexionar sobre las formas de obtener este recurso más limpio y más barato. Como alternativa a esto se promueven intentos de integración entre los diferentes países. El Complejo Madeira tiene un gran potencial para la producción de energía hidroeléctrica, como resultado de caídas y rápido flujo de agua en los afluentes del río Madeira, en especial el río Beni, donde se planea construir una central hidroeléctrica en Cachuela Esperanza, como resultado de la alianza entre Brasil y Bolivia. El proyecto hidroeléctrico está rodeado por controversias y afecta la imagen de Brasil pues éste puede ser considerado como un país oportunista, ya que la mayoría de los impactos negativos de la construcción no se exportarán, y el país se beneficiará de la venta de energía a bajo costo por Bolivia.The energy requirement obliges countries to think on ways to get this resource cleanly and cheaply. Alternative to this are the attempts of integration between different countries. The Madeira Complex has great potential for hydroelectric generation as a result of falls and rapid flow of water in the tributaries of the Madeira river, especially the Beni river, where building a hydroelectric plant in Cachuela Esperanza is planned, as a result of the partnership between Brazil and Bolivia. The hydroelectric project is surrounded by controversy and affects the image of Brazil as opportunistic, since most of the negative impacts resulting from the construction will not be exported, and the country will benefit from the sale of low-cost energy through Bolivia.A necessidade de energia exige aos países a refletir sobre as formas de obter esse recurso mais limpo e mais barato. Como alternativa a isto se promovem esforços de integração entre os diferentes países. O Complexo Madeira tem um grande potencial para a produção de energia hidroelétrica, como resultado de quedas e rápido fluxo de água nos afluentes do rio Madeira, em especial o Rio Beni, onde se planeja construir uma usina hidrelétrica em Cachuela Esperanza, como resultado da aliança entre Brasil e Bolívia. O projeto da hidrelétrica é cercada de polêmicas e afeta a imagem do Brasil, pois este país pode ser considerado como um país oportunista, já que a maioria dos impactos negativos da construção não será exportada, e o país se beneficiará com a venda de energia a baixo custo por parte de Bolívia

Physiological and thermographic response to heat stress in zebu cattle

AbstractThe objective of this study was to evaluate the heat tolerance of five zebu breeds using physical, physiological and hematological traits as well as thermographic responses. Forty cows of the Gir, Girolando, Nelore, Sindhi and Indubrasil breeds (eight cows each), approximately three years of age, were evaluated. Body weight, withers and hump heights as well as thoracic circumference were recorded. The density and length of the hair was obtained by collecting one square centimeter in the rump region and skin color using the CIELAB system. Rectal temperature, heart and respiratory rates were evaluated during the morning at 4:30h, and in the afternoon, at 14:30h, with six repetitions. Blood samples were collected for hematological evaluation. The surface temperature was obtained using an infrared camera FLIR® T400. Two images were taken from each animal, one laterally of the whole body and the other of the head region. Air temperature, wind speed, relative humidity were obtained from a mobile weather station. The statistics analysis included an analyzes of variance, principal factors, as well as cluster, discriminant and canonical analyzes, logistic regression and calculation of odds ratio. There were significant differences in the rectal temperature, heart and respiratory rates between breeds. Gir and Indubrasil breeds had the highest rectal temperatures. Breed was significant for surface temperatures and showed that physical and physiological factors affected breeds in different ways. Eye and brain surface temperatures were the most affected by environmental parameters. Also, environmental parameters affected packed cell volume and red cell number. Odds ratio test showed that the Gir breed was three times more likely to have higher rectal temperature compared with Sindhi as confirmed by the logistic regression. When the black globe temperature approached 35°C, the probability of the Gir animals having rectal temperatures above normal was approximately 70%. Gir was the breed least adapted to climate conditions of the experiment while the Sindhi and Girolando breeds showed the best physiological response to thermal stress

Could more efficient utilization of ecosystem services improve soil quality indicators to allow sustainable intensification of Amazonian family farming?

In the Amazonian periphery, there are sources of numerous disservices, including deforestation, loss of wildlife habitat and biodiversity erosion. However, there are great opportunities to adopt appropriate agricultural management practices to take advantage of the benefits of ecosystem services for sustainable agricultural intensification. Thus, the aim of this work was to evaluate the effects of certain ecosystem services provided by combined use of legumes with residue of low- and high-quality on soil quality indicators, nitrogen use efficiency and sustainability of maize grain yield in infertile tropical soil. The overarching objective is to determine how ecosystem services can contribute to the improvement of land-use policy to ensure the sustainability of cultivated lands, in such a way that forest can be preserved by avoiding deforestation of other new areas through shifting cultivation systems. Four leguminous tree species were used, two with high-quality residues Leucaena leucocephala (leucaena) and Gliricidia sepium (gliricidia) and two with low-quality residues Clitoria fairchildiana (clitoria) and Acacia mangium (acacia). Maize grain yield was evaluated between 2011 and 2017 in these treatments. In 2018, to assess how ecosystem services affect crop performance, the treatments were divided into ten treatments with and without urea. We conclude that increased uptake of inorganic and organic N by maize resulting from improvement of the soil quality indicators may allow agricultural intensification. This improvement can help meet the challenges of sustainability and feasibility of agroecosystems of the Amazonian periphery by making the agroecosystem more productive year by year. Therefore, our results confirm that the utilization of an ecosystem services style approach can help meet the challenges of sustainability and feasibility in agrosystems of the Amazonian periphery. In addition, these results can contribute to the development of land-use policy in the Amazonian periphery, aiming for the intensification of agriculture in cropped areas to avoid deforestation of new areas from shifting cultivation systems

Estímulo no crescimento e na hidrólise de ATP em raízes de alface tratadas com humatos de vermicomposto: i - efeito da concentração.

O vermicomposto contém uma concentração elevada de substâncias húmicas e já é bem conhecido o efeito do seu uso sobre as propriedades do solo. No entanto,a ação direta das substâncias húmicas sobre o metabolismo das plantas é menos conhecida. O objetivo deste trabalho foi avaliar o uso de humatos extraídos de vermicomposto de esterco de curral com KOH 0,1 mol L-1 sobre o desenvolvimento e metabolismo de ATP em plântulas de alface. Após a germinação, plântulas de alface foram tratadas com os humatos em concentrações que variaram de 0 a 100 mg L-1 de C, durante quinze dias. Foram avaliados o crescimento da raiz e a atividade das bombas de H+ isoladas da fração microssomal do sistema radicular. Foi observado aumento na matéria fresca e seca do sistema radicular, bem como no número de sítios de mitose, raízes emergidas do eixo principal, na área e no comprimento radiculares, com o uso do humato na concentração de 25 mg L-1 de C. Também foi observado, nessa concentração, aumento significativo na hidrólise de ATP pelas bombas de H+, responsáveis pela geração de energia necessária à absorção de íons e pelo crescimento celular

Reconstruction of the mouse extrahepatic biliary tree using primary human extrahepatic cholangiocyte organoids

Treatment of common bile duct disorders such as biliary atresia or ischaemic strictures is limited to liver transplantation or hepatojejunostomy due to the lack of suitable tissue for surgical reconstruction. Here, we report a novel method for the isolation and propagation of human cholangiocytes from the extrahepatic biliary tree and we explore the potential of bioengineered biliary tissue consisting of these extrahepatic cholangiocyte organoids (ECOs) and biodegradable scaffolds for transplantation and biliary reconstruction in vivo. ECOs closely correlate with primary cholangiocytes in terms of transcriptomic profile and functional properties (ALP, GGT). Following transplantation in immunocompromised mice ECOs self-organize into tubular structures expressing biliary markers (CK7). When seeded on biodegradable scaffolds, ECOs form tissue-like structures retaining biliary marker expression (CK7) and function (ALP, GGT). This bioengineered tissue can reconstruct the wall of the biliary tree (gallbladder) and rescue and extrahepatic biliary injury mouse model following transplantation. Furthermore, it can be fashioned into bioengineered ducts and replace the native common bile duct of immunocompromised mice, with no evidence of cholestasis or lumen occlusion up to one month after reconstruction. In conclusion, ECOs can successfully reconstruct the biliary tree following transplantation, providing proof-of-principle for organ regeneration using human primary cells expanded in vitro