300 resultados para Tóxicos sutis


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Pós-graduação em Bases Gerais da Cirurgia - FMB

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The routine semen evaluation assessing sperm concentration, motility and morphology, does not identify subtle defects in sperm chromatin architecture. Bulls appear to have stable chromatin, with low levels of DNA fragmentation. However, the nature of fragmentation and its impact on fertility remain unclear and there are no detailed reports characterizing the DNA organization and damage in this species. The intensive genetic selection, the use of artificial insemination and in vitro embryo production associated to the cryopreservation process can contribute to the chromatin damage and highlights the importance of sperm DNA integrity for the success of these technologies. Frozen-thawed semen samples from three ejaculates from a Nellore bull showed high levels of morphological sperm abnormalities (55.8±5.1%), and were selected for complementary tests. Damage of acrosomal (76.9±8.9%) and plasma membranes (75.7±9.3%) as well as sperm DNA strand breaks (13.8±9.5%) and protamination deficiency (3.7±0.6%) were significantly higher compared to the values measured in the semen of five Nellore bulls with normospermia (24.3±3.3%; 24.5±6.1%; 0.6±0.5%; 0.4±0.6% for acrosome, plasma membrane, DNA breaks and protamine deficiency, respectively) (P<0.05). Motility and percentage of spermatozoa with low mitochondrial potential showed no differences between groups. This study shows how routine semen analyses (in this case morphology) may point to the length and complexity of sperm cell damage emphasizing the importance of sperm function testing.

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Pós-graduação em Microbiologia Agropecuária - FCAV

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Agronomia (Proteção de Plantas) - FCA

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The production systems on substrates have been employed in most commercial cultivation of flowers and ornamental plants, including gerbera. However, its introduction as potted flower is recent in Brazil and many studies, especially those related to the determination of substrates physical and chemical properties, which contribute to production quality are still needed. The present study aimed to assess the influence of substrates characteristics for nutrient absorption and production of potted gerbera. The experiment was carried out in greenhouse with the experimental design in randomized blocks, factorial arrangement 5x2 (5 substrates and 2 cultivars) and 4 replications. Treatments consisted of substrates with different physical and chemical characteristics and gerbera cultivars (Cherry and Red). Plants grown on substrate with pH above 7.0 had a reduction in iron absorption, resulting in lower intensity of green coloration in the leaves. Plants grown on substrate with pH below 5.0 showed toxic levels of manganese and lower dry mass. The characteristics of the substrate, especially the pH, influence the nutrients absorption and the production of potted gerbera, altering the final plant quality.

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One of the most primal ways of human work already known is the tessellation and ginning for the production of fabric and clothing - what used to be, back in those days, statement of power and status. The arrival of the Industrial Revolution - in the middle of the XVIII century at Britain - increased the textile industry production, and what used to be manufactured and hard to obtain, starts then to be produced in mechanical ways and large-scale. Despite all the boost given to the economy of an expanding capitalist market, it should be pointed out the consequences of this major industrialization, especially the environmental ones, more and more concerning nowadays. The emissions of waste - that sometimes could be toxic - in effluents can possibly contaminate the aquatic ecosystems, causing a huge damage to its fauna and flora, affecting therefore all the biodiversity, reaching inclusively the humans. To avoid these problems, a few strategies have been taking place in the attempt to eliminate - or at least reduce - the amount of dye found in the effluents, and as the textile industry constantly leaves waste, efficient methods - that present good results in a short period of time - with a low cost are needed. The present study will test the bioremoval capacity of yeast (Saccharomyces cerevisiae) in contact with dyes in a fix concentration, diluted in water with three different pH values. The tests will be done duplicate, and after the concentration analyses - made by spectrophotometry - it will be analyzed which pH shows major efficiency in the dye removal and what is the influence of the biomass in this process

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)