930 resultados para Peixes - Reprodução
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Six microsatellite loci were used to quantify the mating system of two small fragmented populations (Selviria - SEL and Aparecida do Tabuado - APT, Mato Grosso do Sul State) and isolated trees in pastures, of the bat-pollinated tropical tree Hymenaea stignocarpa, growing in the Center-west region of Brazil. In SEL population, seeds were collected from 11 mother-trees; in APT, from three trees and, in the case of isolated trees, from six individuals growing at least 500 m apart in pastures. To investigate if there are differences on mating system between trees in populations and isolated trees, trees from populations were pooled as a group and, likewise, the isolated trees were pooled to another group. The outcrossing rate was higher in the populations (t̂ m= 0.873) than in isolated trees (t̂ m=0.857), but the difference was not significant. Significant and high differences between multi-locus and single-locus outcrossing rate were detected in populations (t̂ m- t̂ s=0.301, P<0.05) and isolated trees (t̂ m- t̂ s=0.276, P<0.05), suggesting mating between relatives. Higher paternity correlation was observed in trees from population (r̂ p=0.636) than in isolated trees (r̂ p=0.377), indicating the occurrence of some correlated matings and that part of offspring are full-sibs. It was not observed increased in self-fertilization rate in isolated trees in pastures. In general terms, the unique observed difference in mating system between populations and isolate trees was the high rate of correlated matings in trees from populations, due probably to the small distance among coespecifics and the pollinator behavior, visiting near trees.
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Aiming to evaluate the association of hydroponic lettuce cultivation with residues from a fish intensive breeding system, a project was carried out in the Aquaculture Center in the FCAV-UNESP at Jaboticabal, SP, Brazil. A closed system was designed in order to allow the water to circulate through the fish tanks, a clarifier tank for removal of residues, a reservoir for biological conversion of ammonia into nitrate, and the hydroponic system. After this process, water returned back to the fish tanks. Three varieties of lettuce, constituting the treatments with four repetitions were evaluated. The results of the chemical analysis of the residual water from the fish tanks indicated the presence of the majority of the mineral nutrients necessary for vegetable development. Their concentration was close to that found in nutrient solutions, used for lettuce hydroponic cultivation, except for potassium and magnesium. The low concentration of magnesium in the water did not prevent lettuce development, although the plants presented visual symptoms of deficiency of this nutrient. Differences were not found between the varieties produced, regarding productivity and the mean weight of fresh plants.
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Aquaculture produces food with high nutritive value, however its environmental conditions and management increase the stress reaction of fishes, prejudicing the quality of their products. The lipid oxidation is one of the main causes of the fishery deterioration, due the high unsaturated value of fatty acid of aquatic organisms. This review describes lipid oxidation mechanisms, their analysis methodology and some preventive ways, emphasizing the antioxidants effects of vitamin E utilization in fish's diet.
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PURPOSE: To compare the diagnostic accuracy of sonohysterography (HSN) and conventional transvaginal ultrasound (USG) in assessing the uterine cavity of infertile women candidate to assisted reproduction techniques (ART). METHODS: Comparative cross-sectional study with 120 infertile women candidate to ART, assisted at Centro de Reprodução Assistida (CRA) of Hospital Regional da Asa Sul (HRAS), Brasília-DF, from August 2009 to November 2010. Sonohysterography was performed with saline solution infusion in a close system. The sonohysterography finding was compared to previous USG results. The uterine cavity was considered abnormal whenthe endometrium was found to be thicker than expectedduring the menstrual cycle and whenan endometrial polyp, a submucous myoma and an abnormal shape of the uterine cavity were observed. The statistical analysis was doneusing absolute frequencies, percentage values and the χ 2, with the level of significance set at5%. RESULTS:HSN revealed that 92 (76.7%) infertile women candidate to ARThad anormal uterine cavity, while 28 (23.3%) had the following abnormalities: 15 polyps (12.5%).
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The present study evaluated the microbiological water quality and tissue lesions in gills from Nile tilapia (Oreochromis niloticus) and hybrid tambacu (Colossoma macropomum female x Piaractus mesopotamicus male). For this, water and gills were collected from fish farming at six locations in Itapecuru- Mirim County, Maranhão State. Microbiological water analyses revealed contamination by total coliforms, Escherichia coli and heterotrophic bacteria. In the gills, we observed a diversity of Gram-positive and Gramnegative bacteria. The tissue lesions were: lamellar fusion, interlamellar hyperplasia, sub-epithelial edema and telangiectasia. Inflammatory lesions were not observed. Significant statistical difference (p > 0.05) was not detected when comparing different gills lesions during rainy and dry season. The correlation between lesion and pond type was statistically different (p < 0.05) for lamellar fusion and interlamellar hyperplasia which occurred more frequently at ground ponds. Regarding the frequency of lesions in the different fish species, there was statistical difference (p < 0.05), and the tambacu was more sensitive to lamellar fusion while tilapia was more sensitive for the other lesions. In relation to the sampling stations, there was statistical difference for all the gill lesions. In conclusion, tissue lesions are nonspecific and function as a defense mechanism against polluted aquatic environments, without infectious character.
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Anthropogenic changes in the reproductive population density can affect the mating system and result in an increase in selfing and correlated matings. This study investigated the mating system in small fragmented populations of the insect pollinated tropical tree species Copaifera langsdorffii, using microsatellite loci and the mixed and correlated mating models. Open-pollinated seeds were collected from 15 seed-trees located in a small forest fragment (4.8 ha), denominated Bosque and from 14 other seed-trees located in other small forest fragments of the north-western region of São Paulo State. No significant differences were observed between the seed-trees from Bosque (tm=0.933±0.028) and other fragments (tm=0.971±0.032), although these estimates were significantly different from 1.0, suggesting that selfing was occurring. Differences between multilocus and unilocus outcrossing rate were significantly high in both seed-trees of Bosque (tm -ts=0.478±0.05) and other forest fragments (tm -ts=0.475±0.018), suggesting a spatial genetic structure in those stands. The results also showed high rates of correlated mating in the samples, indicating that a good part of the offspring were full-sibs. As a consequence of selfing, mating among relatives and correlated matings, the coancestry within families was equally high in the seed-trees of Bosque ((Θ=0.237) and in the seed-trees of the other forest fragments (Θ=0.241) and the effective population size was lower than expected in panmitic populations (Ne<4). The results were discussed, focusing on the sample size of seed-trees to collect seeds for genetic conservation and enviromental reforestation.
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The agonists of gonadotropin-releasing hormone (GnRH) were introduced in ovarian stimulation for in vitro fertilization to avoid a premature surge of luteinizing hormone. Although they are accompanied by some disadvantages, GnRH agonists have become well accepted in clinical practice, and their use is associated with increased rates of pregnancy. The development of GnRH antagonists capable of blocking the pituitary immediately offered a therapeutic option. Comparative studies between the two analogs have suggested that the use of antagonists is associated with a shorter duration of ovulatory stimulus and a decreased incidence of ovarian hyperstimulation syndrome, while the type of GnRH analogues used show no significant effects on the rates of pregnancy and live birth. However, GnRH agonists have other applications in assisted reproductive technology cycles than the pituitary downregulation.
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Incluye Bibliografía
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Aquicultura - FCAV
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)