543 research outputs found

    Sanitary aspects of canal project

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    The canal network in and around the capital of Sri Lanka, Colombo, is in such a deteriorated condition that it can only be compared to a time bomb about to be exploded. Canal water is so polluted that in most places the canals act as anaerobic ponds. This unhealthy condition is further aggravated by the low income communities living along canal banks. The only ray of hope in this dark world is the Canal Rehabilitation Project, the implementation of which assures a healthier environment for those living in close proximity to canals. This paper deals with the present situation of the canal system with relevance to sanitation and the implementation of the canal project to improve the situation

    Repellent action of some insecticides against Oryctes rhinoceros

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    The effectiveness of Aldrex, Aldrin and BHC used as repellents for the control of the coconut black beetle were investigated. Each insecticide was tested at two levels and three application frequencies of 4.8 and 12 weeks. Aldrex was used as 5.6 ml/litre (0.14perc.) or 2.8 ml/litre (0.07perc.). Aldrin 21/2perc. dust and BHC 10perc. dust were used mixed with sand in the ratios, insecticide to sand of 1:2 and 1:4. The Aldrex was poured to the cabbage area and the dusts were used as axil placemets. A highly significant correlation was observed between growth rate of palm and beetle attacks necessitating a correction in the analysis for insecticide effects. Aldrex at 5.6 ml?litre and BHC 10perc. dust as the 1:4 mixture with sand were significantly effective as repellents. The seasonel attack pattern on young palms indicate a correlation between attacks and rainfall, attack peaks occurring approximately seven weeks after a rainfall peak

    Sugar beet agronomic performance evolution in NW Spain in future scenarios of climate change

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    Changes in environmental conditions resulting from Climate Change are expected to have a major impact on crops. In order to foresee adaptation measures and to minimize yield decline, it is necessary to estimate the effect of those changes on the evapotranspiration and on the associated irrigation needs of crops. In the study presented herein, future conditions extracted from RCP4.5 scenario of IPCC, particularized for Castilla-y-León (Spain), were used as inputs for FAO crop simulation model (AquaCrop) to estimate sugar beet agronomic performance in the medium-term (2050 and 2070). A regional analysis of future trends in terms of yield, biomass and CO2 sequestration was carried out. An annual ET0 increase of up to 200 mm was estimated in 2050 and 2070 scenarios, with ETc increases of up to 40 mm/month. At current irrigation levels, temperature rise would be accompanied by a 9% decrease in yield and a ca. 6% decrease in assimilated CO2 in the 2050 and 2070 scenarios. However, it is also shown that the implementation of adequate adaptation measures, in combination with a more efficient irrigation management, may result in up to 17% higher yields and in the storage of between 9% and 13% higher amounts of CO2

    Assessment of RGB vegetation indices to estimate chlorophyll content in sugar beet leaves in the final cultivation stage

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    Estimation of chlorophyll content with portable meters is an easy way to quantify crop nitrogen status in sugar beet leaves. In this work, an alternative for chlorophyll content estimation using RGB-only vegetation indices has been explored. In a first step, pictures of spring-sown ‘Fernanda KWS’ variety sugar beet leaves taken with a commercial camera were used to calculate 25 RGB indices reported in the literature and to obtain 9 new indices through principal component analysis (PCA) and stepwise linear regression (SLR) techniques. The performance of the 34 indices was examined in order to evaluate their ability to estimate chlorophyll content and chlorophyll degradation in the leaves under different natural light conditions along 4 days of the canopy senescence period. Two of the new proposed RGB indices were found to improve the already good performance of the indices reported in the literature, particularly for leaves featuring low chlorophyll contents. The 4 best indices were finally tested in field conditions, using unmanned aerial vehicle (UAV)-taken photographs of a sugar beet plot, finding a reasonably good agreement with chlorophyll-meter data for all indices, in particular for I2 and (R−B)/(R+G+B). Consequently, the suggested RGB indices may hold promise for inexpensive chlorophyll estimation in sugar beet leaves during the harvest time, although a direct relationship with nitrogen status still needs to be validated

    Quantum circuits for spin and flavor degrees of freedom of quarks forming nucleons

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    We discuss the quantum-circuit realization of the state of a nucleon in the scope of simple symmetry groups. Explicit algorithms are presented for the preparation of the state of a neutron or a proton as resulting from the composition of their quark constituents. We estimate the computational resources required for such a simulation and design a photonic network for its implementation. Moreover, we highlight that current work on three-body interactions in lattices of interacting qubits, combined with the measurement-based paradigm for quantum information processing, may also be suitable for the implementation of these nucleonic spin states.Comment: 5 pages, 2 figures, RevTeX4; Accepted for publication in Quantum Information Processin

    Relação Custo Benefício na Produção de Silagem com Milho Bt

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    Eficiência e escala de produção são imprescindíveis para obtenção de retornos financeiros compensatórios na atividade pecuária. O aumento da produtividade demanda maior produção de energia digestível por área, a fim de suprir plenamente as exigências nutricionais dos animais ao longo do ano de forma menos dispendiosa. O custo com alimentação dos animais se eleva no período seco do ano devido à redução no crescimento das plantas forrageiras. Segundo Magalhães et al. (2004) as despesas com alimentação atingem 64,9% da receita obtida com a venda do leite e no período seco a silagem e os grãos de milho (Zea mays), compõem a maior parte da ração animal. O milho representa a principal cultura armazenada em forma de silagem para utilização ao longo do período de estiagem, devido à possibilidade de boas produções com alto valor nutritivo. O armazenamento de forragem na forma de silagem para alimentação dos animais no período da seca é um processo de custo elevado, cujo benefício relaciona-se diretamente com o volume e qualidade da massa produzida. As silagens de milho no Brasil possuem média qualidade e rendimento abaixo do potencial da planta no que diz respeito à produção de energia digestível por área. O alto custo da produção de silagem, muitas vezes decorre da baixa produtividade das culturas. Fatores como adubação e correção da acidez do solo, controle de invasoras e pragas, escolha da época certa para o corte, tamanho adequado de partículas, tempo de fechamento do silo, densidade alcançada com a compactação e vedação, tipo de silo e lona utilizada na vedação, controle de contaminação e manejo após abertura quando não executados corretamente, podem acarretar sérias perdas econômicas na produção de bovinos. A utilização de cultivares modernos, mais produtivos, adaptados às condições locais e resistentes a pragas pode representar ganhos efetivos em produtividade desde que não ocorram fatores limitantes a manifestação do potencial produtivo dessas culturas. A lagarta-do-cartucho, uma das principais pragas do milho no Brasil, distribui-se em todas as regiões de cultivo e pode reduzir a produção em até 38,7% (Williams & Davis 1990). O controle é convencionalmente realizado por produtos químicos e biológicos e sua necessidade condiciona-se ao nível de infestação. No ano de 2007 a Comissão Técnica Nacional de Biossegurança liberou a comercialização de híbridos geneticamente modificados resistentes a pragas. A tecnologia desenvolvida em híbridos de milho contendo o gene da bactéria Bacillus thuringiensis (Bt), que expressa a proteína Cry1Ab, tornou os híbridos resistentes ao ataque da lagarta-do-cartucho (Spodoptera frugiperda), lagarta-da-espiga (Helicoverpa zea) e broca do colmo (Diatraea saccharalis) (Avisar et al., 2009), reduzindo o controle químico e os custos com a aplicação de defensivos. Vários trabalhos comparando híbridos de milho transgênicos com suas contrapartes convencionais, demonstraram equivalência da composição química da silagem e produção e composição do leite (Faust & Miller, 1997; Folmer et al., 2002; Donkin et al., 2003; Calsamiglia et al., 2007; Faust et al., 2007). De acordo com Wiedemann et al. (2006) é improvável que uma proteína Cry1Ab inteira e funcional seja encontrada no rúmen após 8 horas de incubação. Segundo Singhal et al. (2006) não foi possível detectar a proteína codificada pelos genes cry1Ac e cry2Ab no sangue ou no leite dos animais alimentados. Dessa forma, os alimentos derivados de animais recebendo forrageiras modificadas geneticamente são considerados tão seguros quanto àqueles derivados de animais alimentados com forragem convencional, (Flachowsky et al., 2005; Phipps et al., 2006). O foco deste trabalho foi avaliar os benefícios econômicos do cultivo de híbridos de milho transgênicos destinados à confecção de silagem para alimentação animal utilizando como parâmetros a produção e qualidade da forragem. Para tanto foram observadas a produção agronômica, características morfológicas, perdas fermentativas, perdas aeróbias, composição química, digestibilidade in vivo, desempenho animal e os custos, das sementes e com aplicação de inseticidas. A decisão de qual hibrido ensilar é de grande importância no planejamento da atividade pecuária bovina e demanda avaliação técnica e econômica. O texto que segue tem como base os resultados de uma série de ensaios comparando a utilização dos híbridos de milho DKB 390 da Dekalb e AG 8088 da Agroceres contendo o gene cry1Ab com suas respectivas contrapartes convencionais sem o gene Bt (isogênicos próximos). As pesquisas foram conduzidas no Pólo Centro Leste da Agência Paulista de Tecnologia dos Agronegócios da Secretaria de Agricultura e Abastecimento do Estado de São Paulo - APTA/SAA e tiveram auxílio financeiro da FAPESP e CNPq

    Reproductive performance of sows inseminated with semen doses stored for up to seven days in long-term extender in a field condition

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    This study aimed to evaluate the reproductive performance of sows inseminated with semen doses preserved at 15-18 °C for up to seven days in long-term extender (Duragen®). Parity one (PO1) to PO7 sows were randomly assigned to the following groups: AI1-3 (n=190), insemination with semen doses stored between one and three days; and AI5-7 (n=124), insemination with semen doses stored between five and seven days. Sows were submitted to estrus detection twice a day. Post-cervical insemination according to weaning-to-estrus interval was performed. The farrowing rate (FR) did not differ between the groups (AI1-3=83.2%; AI5-7=82.2%; p>0.05) nor did the total number of piglets born (TPB; AI1-3=14.2±0.3; AI5-7=14.5±0.3; p>0.05). Considering the semen dose most likely responsible for fertilization according to its storage time (1, 2-3, 5, and 6-7 days), the FR (72.7%, 87.8%, 85.7%, and 79%, respectively) and TPB (14.4, 14.0, 14.9, and 13.5, respectively) were similar among the groups (p>0.05). In conclusion, the use of semen doses extended with long-term extender stored for up to seven days did not impair the reproductive performance of sows. Therefore, it’s using could optimize production efficiency and logistics of semen dose deliveries to sow farms

    Low-Energy Brane-World Effective Actions and Partial Supersymmetry Breaking

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    As part of a programme for the general study of the low-energy implications of supersymmetry breaking in brane-world scenarios, we study the nonlinear realization of supersymmetry which occurs when breaking N=2 to N=1 supergravity. We consider three explicit realizations of this supersymmetry breaking pattern, which correspond to breaking by one brane, by one antibrane or by two (or more) parallel branes. We derive the minimal field content, the effective action and supersymmetry transformation rules for the resulting N=1 theory perturbatively in powers of kappa = 1/M_{Planck}. We show that the way the massive gravitino and spin-1 fields assemble into N=1 multiplets implies the existence of direct brane-brane contact interactions at order O(kappa). This result is contrary to the O(kappa^2) predicted by the sequestering scenario but in agreement with recent work of Anisimov et al. Our low-energy approach is model independent and is a first step towards determining the low-energy implications of more realistic brane models which completely break all supersymmetries.Comment: Latex, 29 Page

    Electroanalytical method for the analysis of methyldopa in pharmaceutical tablets using a crude extract of laccase from Pycnoporus sanguineus as oxidizing agent

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    Several colorimetric and chromatographic methods have been used for the identification and quantification of methyldopa (MA) in pharmaceutical formulations and clinical samples. However, these methods are time- and reagent-consuming, which stimulated our efforts to develop a simple, fast, and lowcost alternative method. We carried out an electroanalytical method for the determination of MA in pharmaceutical formulations using the crude enzymatic extract of laccase from Pycnoporus sanguineus as oxidizing agent. This method is based on the biochemical oxidation of MA by laccase (LAC), both in solution, followed by electrochemical reduction on glassy carbon electrode surface. This method was employed for the determination of MA in pure and pharmaceutical formulations and compared with the results obtained using the official method. A wide linear curve from 2.5 x 10-5 to 1 x 10-4 mol L-1 was found with a detection limit calculated from 4.5 x 10-6 mol L-1.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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