4,705 research outputs found

    Dinâmica sazonal do carbono em campo úmido do cerrado.

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    Production of chlorella vulgaris biomass on uv-treated wastewater as an alternative for environmental sustainability on high-mountain fisheries

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    The sustained expansion of agricultural industry in Colombian high-mountain has led to an increased size of residues, especially untreated wastewater. This untreated water is an urgent matter for public and environmental health, not only by its nutrient concentration (composed especially of food residuals and feces) but also the presence of pathogens (virus, bacteria, etc.) which are discharged to the environment. The overall objective of this work is to evaluate the effect of UV-treated wastewater from a high-mountain fishery as culture media for the production of Chlorella vulgaris as a sustainable method for nutrient and water recirculation on the fishery production system. The UV-canal efficiency was evaluated by the implementation of an experimental factorial design (time, distance of the UV-lamps towards the canal, number of UV-lamps and the sample concentration) using STATISTICA 7.0 software. Results shown that time (3 to 5 minutes) and the number of lamps (3-4) of 15 Watts eliminate completely coliforms from the samples. After UV-treatment the resulting water was test as culture media for C. vulgaris production by the adjustment of C/N ratio (Sodium Carbonate/potassium nitrate) by the implementation of an experimental 23 factorial design. Results shown that higher nitrate concentrations (>0,22 g/L) and moderate carbonate concentrations (1 g/L) increase the final biomass concentration up to 4g/L in 20 days

    Where the grass is greenest in seagrass seascapes depends on life history and simple species traits of fish

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    Tropical seagrass meadows are critical habitats for many fish species, yet few studies have investigated the influence of multiple scale-dependent factors and marine protected areas on seagrass fish species of differing life histories. We assessed the influence of fine-scale seagrass meadow characteristics and seascape-scale variables on the abundance of fish in a seagrass-dominated seascape in the Bazaruto Archipelago, Mozambique, particularly examining patterns of nursery- vs. resident species as well as mobile- vs. sedentary species. We found that fish distribution patterns in this seagrass-dominated seascape were dependent on species' life history characteristics; nursery taxa showed lower abundance in seagrass meadows further from adult reef habitats, while resident species within seagrass meadows occurred in higher abundances far from reefs. For taxa utilizing both mangroves and seagrass meadows as nursery habitat, proximity to mangroves was an important factor. Fish abundances were generally influenced by variables at the seascape scale (km), while sedentary species were predominantly influenced by area variables, and smaller seascapes (<500 m in radius) better explained distribution patterns. The influence of marine protected areas was taxon-specific, with the strongest effects of protection on resident species. Our results indicate that protection efforts in seagrass-dominated seascapes can have varying impacts on fish distribution, depending on the life history of the species present, and the geographical placement of the reserve within the seascape. Further, we suggest that simple species attributes can be utilised to describe generalized abundance patterns of fish in seagrass seascapes

    Terminological challenges in the translation of science documentaries: a case-study

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    This article aims to describe some of the main terminological problems audiovisual translators have to face when dealing with the translation of science documentaries, specifically in the English-Catalan combination. The first section of the article presents some theoretical concepts which underlie this research and which are taken, for the most part, from Cabré's Communicative Theory of Terminology. Then, specific terminological problems audiovisual translators have to solve are described using the data provided by a corpus of four science documentaries lasting approximately 50 minutes each. These challenges include identifying a term, understanding a term, finding the right equivalent, dealing with the absence of an adequate equivalent, solving denominative variations, choosing between in vivo and in vitro terminology, and overcoming mistranscriptions

    Spread of vaccinia virus to cattle herds, Argentina, 2011

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    To the Editor: Since 1999, several zoonotic outbreaks of vaccinia virus (VACV) infection have been reported in cattle and humans in rural areas of Brazil. The infections have caused exanthematous lesions on cows and persons who milk them, and thus are detrimental to the milk industry and public health services (1,2). In Brazil during the last decade, VACV outbreaks have been detected from the north to the extreme south of the country (1–4). Because Brazil shares extensive boundaries with other South American countries, humans and cattle on dairy and beef-producing farms in those countries may be at risk of exposure to VACV. To determine if VACV has spread from Brazil to Argentina, we investigated the presence of VACV in serum samples from cattle in Argentina.Facultad de Ciencias VeterinariasComisión de Investigaciones Científicas de la provincia de Buenos Aire

    Spread of vaccinia virus to cattle herds, Argentina, 2011

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    To the Editor: Since 1999, several zoonotic outbreaks of vaccinia virus (VACV) infection have been reported in cattle and humans in rural areas of Brazil. The infections have caused exanthematous lesions on cows and persons who milk them, and thus are detrimental to the milk industry and public health services (1,2). In Brazil during the last decade, VACV outbreaks have been detected from the north to the extreme south of the country (1–4). Because Brazil shares extensive boundaries with other South American countries, humans and cattle on dairy and beef-producing farms in those countries may be at risk of exposure to VACV. To determine if VACV has spread from Brazil to Argentina, we investigated the presence of VACV in serum samples from cattle in Argentina.Facultad de Ciencias VeterinariasComisión de Investigaciones Científicas de la provincia de Buenos Aire

    Política de estabilização de renda para a agricultura familiar: uma análise de risco.

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    Os produtores familiares foram prejudicados pelas políticas de substituição de importações e de modernização da agricultura, sofrendo com elevadas transferências de renda para fora do setor. Uma forma de ressarci-los seria implementando uma política de estabilização de renda que asseguraria rentabilidade estável aos produtores. O objetivo deste artigo é determinar os benefícios de uma política de estabilização de renda implementada na agricultura familiar para agricultores e consumidores de arroz, feijão, milho e mandioca, e os custos para agricultores comerciais nesses mercados. Utilizou-se o modelo de Newbery e Stiglitz, que considera a redução do risco com a política de estabilização de renda. A política implicaria aumento de receita para produtores familiares. Os benefícios de transferência superariam os de eficiência para produtores familiares e consumidores. Os benefícios para a agricultura familiar superariam os custos da agricultura comercial com a política nos mercados de feijão, mandioca e milho, e os benefícios totais superariam os custos totais nos mercados de feijão e milho, ao contrário ocorreria nos mercados de arroz e mandioca, embora neste fosse pequena a diferença. Conclui-se que a implementação da política seria viável nos mercados onde a participação da agricultura familiar fosse maior que a da comercial e naqueles importadores

    Synthesis of titanate nanostructures using amorphous precursor material and their adsorption/photocatalytic properties

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    This paper reports on a new and swift hydrothermal chemical route to prepare titanate nanostructures (TNS) avoiding the use of crystalline TiO2 as starting material. The synthesis approach uses a commercial solution of TiCl3 as titanium source to prepare an amorphous precursor, circumventing the use of hazardous chemical compounds. The influence of the reaction temperature and dwell autoclave time on the structure and morphology of the synthesised materials was studied. Homogeneous titanate nanotubes with a high length/diameter aspect ratio were synthesised at 160^{\circ}C and 24 h. A band gap of 3.06\pm0.03 eV was determined for the TNS samples prepared in these experimental conditions. This value is red shifted by 0.14 eV compared to the band gap value usually reported for the TiO2 anatase. Moreover, such samples show better adsorption capacity and photocatalytic performance on the dye rhodamine 6G (R6G) photodegradation process than TiO2 nanoparticles. A 98% reduction of the R6G concentration was achieved after 45 minutes of irradiation of a 10 ppm dye aqueous solution and 1 g/L of TNS catalyst.Comment: 29 pages, 10 figures, accepted for publication in Journal of Materials Scienc
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