188 resultados para Sedimentary Parameters


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

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

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

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The influence of daily energy doses of 0.03, 0.3 and 0.9 J of He-Ne laser irradiation on the repair of surgically produced tibia damage was investigated in Wistar rats. Laser treatment was initiated 24 h after the trauma and continued daily for 7 or 14 days in two groups of nine rats (n=3 per laser dose and period). Two control groups (n=9 each) with injured tibiae were used. The course of healing was monitored using morphometrical analysis of the trabecular area. The organization of collagen fibers in the bone matrix and the histology of the tissue were evaluated using Picrosirius-polarization method and Masson's trichrome. After 7 days, there was a significant increase in the area of neoformed trabeculae in tibiae irradiated with 0.3 and 0.9 J compared to the controls. At a daily dose of 0.9 J (15 min of irradiation per day) the 7-day group showed a significant increase in trabecular bone growth compared to the 14-day group. However, the laser irradiation at the daily dose of 0.3 J produced no significant decrease in the trabecular area of the 14-day group compared to the 7-day group, but there was significant increase in the trabecular area of the 15-day controls compared to the 8-day controls. Irradiation increased the number of hypertrophic osteoclasts compared to non-irradiated injured tibiae (controls) on days 8 and 15. The Picrosirius-polarization method revealed bands of parallel collagen fibers (parallel-fibered bone) at the repair site of 14-day-irradiated tibiae, regardless of the dose. This organization improved when compared to 7-day-irradiated tibiae and control tibiae. These results show that low-level laser therapy stimulated the growth of the trabecular area and the concomitant invasion of osteoclasts during the first week, and hastened the organization of matrix collagen (parallel alignment of the fibers) in a second phase not seen in control, non-irradiated tibiae at the same period. The active osteoclasts that invaded the regenerating site were probably responsible for the decrease in trabecular area by the fourteenth day of irradiation. (C) 2003 Elsevier B.V. All rights reserved.

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Austroplenckia populnea (Reiss.) Lundell. was selected for this study because it has been shown that some plants from the Celastraceae family have antifertility effects. Twelve adult male rats were treated with hydromethanolic extract made from the leaves, 500 mg/kg/day, orally, for 70 days. Distilled water was administered to the control animals (n = 10). At the end of the experiment, and before killing the rats, their sexual behavior was evaluated. The number of intromissions, latencies to first mount and ejaculation, and first intromission after ejaculation were significantly reduced in the treated group, but the total number of ejaculations did not differ from the control group. The weight and histology of the reproductive organs, sperm production, spermatogenesis, prostate fructose content, cauda epidydimides duct diameter, and sperm morphology were not affected. Sperm concentration in cauda epidydimides was significantly decreased. The results showed that A. populnea has effects on male rat reproduction, affecting the sexual behavior and epididymal sperm concentration. (C) 2002 Elsevier B.V. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Catch and selectivity parameters using gillnets were calculated for Schizodon nasutus in the Jurumirim reservoir on the Parana-panema River in southern Brazil. The simple gillnets used were made of monofilament nylon of 30 to 140 mm mesh size an of different heights. The relative abundance of the S. nasutus caught was analysed monthly and a positive relationship was found between catches per unit effort in number and biomass. The relative catches were more abundant for the nets of 40 and 50 mm, mesh size. Catches were characterized by clear temporal variations and a predominance of medium size fish throughout the study period. The selectivity curve of gillnets for S. nasutus in this ecosystem was obtained. The catch obtained was compared with the available catch for each mesh size, and the available catch for a certain length of fish was calculated starting from the theoretical selectivity curve. The 50 mm mesh size gillnet showed the best fit between real and available captures and was considered the most suitable, because a smaller mesh size resulted in a catch of predominantly immature specimens. It is expected that these results will contribute to improving management strategies for conservation of resources. Parameters such as the minimum catch length advisable or the mesh size permitted for a given species are indispensable for such decision-making.

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Tropidurid lizards have colonized a variety of Brazilian open environments without remarkable morphological variation, despite ecological and structural differences among habitats used. This study focuses on two Tropidurus sister-species that, despite systematic proximity and similar morphology, exhibit great ecological divergence and a third ecologically generalist congeneric species providing an outgroup comparison. We quantified jumping capacity and sprint speed of each species on sand and rock to test whether ecological divergence was also accompanied by differences in locomotor performance. Relevant physiological traits possibly associated with locomotor performance metabolic scopes and fiber type composition, power output and activity of the enzymes citrate synthase, pyruvate kinase and lactate dehydrogenase of the iliofibularis muscle - were also compared among the three Tropidurus species. We found that the two sister-species exhibited remarkable differences in jumping performance, while Tropidurus oreadicus, the more distantly related species, exhibited intermediate values. Tropidurus psamonastes, a species endemic to sand dunes, exhibited high absolute sprint speeds on sand, jumped rarely and possessed a high proportion of glycolytic fibers and low activity of citrate synthase. The sister-species Tropidurus itambere, endemic to rocky outcrops, performed a large number of jumps and achieved lower absolute sprint speed than T. psamonastes. This study provides evidence of rapid divergence of locomotor parameters between sister-species that use different substrates, which is only partially explained by variation in physiological parameters of the iliofibularis muscle.

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

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This paper aims to study the ecological system of the Pardo River, at the source and lower-order passages, which are in the Botucatu area, São Paulo State, Brazil. This study was carried out to determine water quality with some chemical-physical indicators, coliforms, and chemical species of samples taken monthly, 1995/02-1996/01, from eight sampling stations sited along the Pardo River. The results in the river monitoring are discussed based on annual averages, analysis of variance, and compared to Tukey's Studentized Range-HSD, and principal component analysis (PCA) was applied to normalize data to assess association between variables. We can conclude that the variables used are very efficient for identifying and that the dry season shows the worst water quality. These were caused by organic matter, nutrients (originate) from anthropogenic sources (spatial sources) and mainly municipal wastewater, affecting the quality and hydrochemistry of the river water, which have been differentiated and assigned to polluting sources. Meanwhile, the degree of degradation of the Pardo River is low (sewage treatment carried out by the city of Pardinho is efficient), leaving the water of the river suitable for use by the population of Botucatu, after conventional treatment (Conama, Resolucao No. 20, CONAMA, Brazilia DF, 09-23, 1986-the water of the Pardo river is classified as level 03). (C) 2001 Elsevier B.V. Ltd. All rights reserved.

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Passiflora alata (Passifloraceae) is a native plant from the South-America tropical forest that provides a much apreciated fruit known as maracuja-doce. Although tea of the leaves of Passiflora alata is used in folk medicine as a sedative and tranquilizer, there are no investigations about its effects on biochemical parameters in blood or from its major chemical composition. The purpose of this study was to evaluate the effects of the tea of the leaves of Passiflora alata on biochemical parameters (antioxidant system, glucose and cholesterol levels) and to perform a phytochemical investigation of the tea. We isolated and identified two saponins and five C-glycosylflavones derived from apigenin, luteolin and chrysoeriol. Three of them are new in this species. Passiflora alata extract was administrated orally in rats at dose of 1000 mg/kg and it was observed an increase in high-density lipoprotein level (HDL-cholesterol). (C) 2004 Elsevier B.V.. All rights reserved.

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Dentre as numerosas terapias para minimizar as complicações diabéticas, os antioxidantes e flavonoides são testados na clínica médica. Foi analisado o efeito da naringerina sobre os parâmetros bioquímicos em ratos diabéticos induzidos por estreptozotocina (STZ - 60mg/kg, i.p.). Ratos machos foram divididos em 4 grupos: G1: controle não tratado; G2: ratos normais que receberam naringerina; G3: diabéticos não tratados; G4: ratos diabéticos que receberam naringerina. Naringerina (50mg/kg, i.p.), decresceu a hiperglicemia e a hiperlipidemia em ratos diabéticos. A concentração sérica de insulina em ratos tratados tendeu aumentar. A naringerina preveniu as alterações, provocadas pela estreptozotocina, na atividade hepática e cardíaca de ALT, AST e LDH, indicando o efeito protetor da naringerina sobre estes tecidos, contra toxicidade provocada pela STZ. O nível de glicogênio nos tecidos cardíaco e hepático elevou com a naringerina em ratos diabéticos. A naringerina melhorou o metabolismo da glicose e de lipídios e preveniu as complicações diabéticas.

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Specimens of the zipper sand skate Psammobatis extenta were collected in the region of Ubatuba off the northern coast of the State of São Paulo, Brazil, monthly for once year (January - December 2000), at 25- to 40-m isobaths. A total of 123 individuals were caught. The total length (TL) of females averaged 224.6 mm, and of males 217 mm. The overall sex ratio was 1:1. Analysis of the length-weight relationship indicated the existence of positive allometry in females, and isometry in males. The length at onset of sexual maturity was determined for both sexes; females reached sexual maturity at smaller sizes than males (TL50 = 230.7 and TL50 = 237.7 mm respectively). Females showed functional parity of both ovaries and uteri. Females that were pregnant or were carrying vitellogenic oocytes were observed during nine of 12 months of the survey, indicating a continuous reproductive cycle. Psammobatis extenta was most abundant from January to April, and again from June to October. Most individuals were collected at the 40-m isobath. Both adults and neonates were collected in the study area. However, adolescent skates were scarce, which either indicates differential occupation of the area, or suggests that the shallow waters of the continental shelf are used as breeding grounds.