906 research outputs found
Fermentative enzymes activity in soybean roots and nodules under hypoxia and post-hypoxia conditions.
Mechanisms regulating bitter pit development in Greensleeves apples with suppression of ethylene biosynthesis.
The objectives of this study were to understand the role of ethylene and nutrients (Ca2+,Mg2+, K+ and N) on bitter pit (BP) development in wild type (GS) and ethylene suppressed (68G and 103Y) Greensleeves apples. The transgenic line 68G is suppressed for 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) and line 103Y is suppressed for ACC synthase (ACS). Suppression of ethylene biosynthesis reduced BP incidence and severity. Lower ethylene biosynthesis, in ethylene-suppressed genotypes, had no effect on Ca2+, Mg2+, K+ and N concentrations in fruit cortical tissue. In all genotypes, fruit with BP had lower Ca2+ and higher Mg2+ concentrations and higher Mg2+/Ca2+ ratio in cortical tissue. The results indicate that high levels of ethylene biosynthesis and Mg2+ in cortical tissue can enhance fruit susceptibility to BP incidence
Avaliação do impacto de um programa de treino diferencial vs prática variada na dimensão motora e cognitiva de jovens futebolistas.
O objetivo deste estudo foi o de comparar o impacto de um programa de treino com enfoque na abordagem diferencial e outro programa na Prática Variada sobre a prestação motora de praticantes de futebol. A amostra foi constituída por vinte e dois praticantes de futebol (12 ± 1.15 anos) que integraram os dois grupos experimentais: i) Aprendizagem Diferencial (AD) (n=11, 12 ± 1.26 anos) e ii) Prática Variada (PV) (n=11, 12 ± 1.10 anos). O programa de intervenção envolveu duas sessões semanais, com duração de 90 minutos cada, ao longo de 8 semanas. No início (pré) e no final (pós) do programa procedeu-se à avaliação do desempenho físico e técnica em baterias de teste específicos bem como à avaliação do desempenho em situação de jogo reduzido. Os resultados obtidos indicam uma evolução relativamente homogénea na prestação motora dos dois grupos entre o pré-teste e o pós-teste. Registou-se uma melhoria significativa em ambos os grupos nas variáveis força explosiva, agilidade, remate e receção. Curiosamente, o drible foi a única variável onde o grupo de Aprendizagem Diferencial apresentou uma evolução significativamente superior ao grupo de Prática Variada. Por sua vez, o grupo de Prática Variada apresentou uma evolução mais significativa que o grupo de Aprendizagem Diferencial no passe avaliado em situação de jogo reduzido. Pode-se assim concluir que neste estudo-caso, e em contraste com investigações prévias, não se identificou um efeito benéfico em termos de desempenho pela adoção da abordagem com enfâse no treino diferencial. Aparentemente, a implementação de abordagens que envolvem uma noção distinta de variabilidade produziu efeitos semelhantes no desempenho de jovens praticantes de futebol
Escaldadura superficial em maçãs Granny Smith submetidas ao tratamento térmico com cálcio.
O objetivo deste trabalho foi avaliar o efeito do tratamento térmico combinado com Ca2+ sobre o desenvolvimento de escaldadura superficial em maçãs Granny Smith após o armazenamento refrigerado
Using hydropower waterway locks for energy storage and renewable energies integration
Waterway are one of the most efficient means for transportation. It can be applied for energy storage demonstrating the potential of using these structures with renewable energy systems, here, through an analysis of energy alternatives. This paper analyzes two different solutions for energy supply, using the Locks of the Tucuruí powerplant, in Brazil. A photovoltaic power station is compared to a hybrid system composed by photovoltaic and pumped storage. The alternatives are discussed technically and economically. The energy costs of the scenarios are calculated based on the evolution of the expenses and the related payback time are found. The water resource is exploited responsibly, keeping balanced the pumped and turbined volumes of water. The grid works as an intermediate storage and allows the operations with a single pump-turbine conversion. Its location lowers down the initial investment in favor of the hybrid system as the more viable alternative. It was found that the locks could be used to handle up to 263 kW and 387 kW of electricity in turbine and pump mode, respectively. This paper gathers crucial data on the use of hydropower in waterways locks that support the integration of renewable energies surrounding the locks. In addition, the use of pumped storage plants to store energy from intermittent sources, present themselves as an innovative opportunity to, using the own head available at facility, improve the financial return of meeting the energy demand through an economically and environmentally responsible energy system, may be useful in similar facilities around the world
Anthelmintic activity of Cymbopogon schoenanthus and Cymbopogon martinii essential oils evaluated by four different in vitro tests.
Gastrointestinal helminths in calves and cows in an organic milk production system
The main aim of this study was to determine the distribution of populations of gastrointestinal helminths in lactating crossbred cows and calves during the grazing season in an organic milk production system. In addition, the potential importance of the peripartum in relation to the parasite load was examined. Between January 2007 and December 2008, parasitological fecal examinations were performed on cattle belonging to the Integrated Animal Production Program of Embrapa Agrobiology. The cows' parasite load remained low during the study period, and there were no statistical differences (p > 0.05) in comparisons between the seasons. The average egg count showed a positive correlation (0.80) with the peripartum, such that egg elimination per gram (p < 0.05) was higher during the week of labor than during the pre and postpartum periods. Calves showed low parasite loads, with significantly higher egg elimination (p < 0.05) during the winter. The study indicated that infection with gastrointestinal helminths was not a limiting factor for milk production in the organic system. Specifically, it was concluded that the nematode load can be maintained at moderate levels throughout the production system, even in the absence of anthelmintic treatment
Morfologia e Vascularização do Plexo Braquial no Rato Wistar
Introduction: The rat is probably the animal species most widely used in experimental studies on nerve repair. The aim of this work was to contribute to a better understanding of the morphology and blood supply of the rat brachial plexus. Material and Methods: Thirty adult rats were studied regarding brachial plexus morphology and blood supply. Intravascular injection and dissection under an operating microscope, as well as light microscopy and scanning electron microscopy techniques were used to define the microanatomy of the rat brachial plexus and its vessels. Results: The rat brachial plexus was slightly different from the human brachial plexus. The arterial and venous supply to the brachial plexus plexus was derived directly or indirectly from neighboring vessels. These vessels formed dense and interconnected plexuses in the epineurium, perineurium, and endoneurium. Several brachial plexus components were accompanied for a relatively long portion of their length by large and constant blood vessels that supplied their epineural plexus, making it possible to raise these nerves as flaps. Discussion: The blood supply to the rat brachial plexus is not very different from that reported in humans, making the rat a useful animal model for the experimental study of peripheral nerve pathophysiology and treatment. Conclusion: Our results support the homology between the rat and the human brachial plexus in terms of morphology and blood supply. This work suggests that several components of the rat brachial plexus can be used as nerve flaps, including predominantly motor, sensory or mixed nerve fibers. This information may facilitate new experimental procedures in this animal model
Paradise revealed: first-class science rocked by the sound of the waves
Univ São Paulo, Inst Ciencias Biomed, Dept Imunol, BR-05508900 São Paulo, BrazilInst Nacl Ciencia & Tecnol, Inst Invest Imunol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, Diaderna, SP, BrazilFundacao Oswaldo Cruz, Inst Oswaldo Cruz, Lab Imunofarmacol, Rio de Janeiro, BrazilUniv São Paulo, Fac Med, BR-05508900 São Paulo, BrazilInst Nacl Canc, Div Biol Celular, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, Diaderna, SP, BrazilWeb of Scienc
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