150 resultados para Pelagic and littoral regions
em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"
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The abundance of zooplankton in two lakes of Southwest Amazonia was studied for 10 months in different regions and at different periods of the day. The lakes were Lago Amapá, located at 10°02′36″S, 67°50′24″W, and Lago Pirapora, at 9°27′21″S, 67°31′39″. Both lakes are characterized as oxbow lakes. The aim of this study was to compare the pelagic and littoral regions, as well as to determine differences in the distribution of zooplankton in the water column in the morning and at night. Collections were made by filtering water through a 55μm zooplankton net into a 5L Van Dorn bottle, collecting 4L from the top and 5L from the middle and bottom layers, totaling 14L of water for each sampling location. In addition, physical and chemical parameters were measured, including transparency, temperature, pH, dissolved oxygen, electrical conductivity and turbidity. Anova (analysis of variance) and Tukey's test were used. There was no statistically significant difference between the regions studied, nor between the two time periods examined. The results of the Pearson correlation (p<0.05) demonstrated that the physical and chemical characteristics of the water correlated with the cladocerans Moina spp. (represented by M. minuta and M. reticulata) and Ceriodaphnia cornuta, and that Daphnia gessneri was associated with Chaoboridae.
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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This project verified the potential for the production of hydrogen via water electrolysis by using the exceeding electrical energy resultant from alcohol and sugar plants that use sugar cane bagasse as fuel. The studies were carried out in cogeneration plants authorized by the Electrical Energy National Agency (ANEEL). The processing history of sugar cane considered was based on the 2006/2007 harvests. The total bagasse produced, electrical energy generated and exceeding electrical energy in a year were calculated. It was obtained an average energy consumption value of 5.2 kWh Nm(-3) and the hydrogen production costs regarding the amount of sugar cane processed that ranged from US$ 0.50 to US$ 0.75 Nm(-3). The results pointed that the costs for the production of hydrogen via the bagasse exceeding energy are close to the production costs that use other sources of energy. As the energy generated from the bagasse is a renewable one, this alternative for the production of hydrogen is economical and environmentally viable. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The main purpose of the present study was to investigate the occurrence of antibodies against T gondii and N. caninum in captive maned wolves from Brazil, considering that little information is available at the literature about infections by these parasites in this wild animal. Serum samples were obtained from 59 maned wolves originated from six zoos and from one ecological reserve of the southeastern and midwestern regions of Brazil. To detect IgG antibodies against T gondii, an ELISA protocol was used and the results were expressed as ELISA reactivity indexes (131). Serology for N. caninum was carried out by indirect fluorescent antibody test (IFAT) and cut-off titers were established at 1:25 dilution. From the total of the analyzed samples, 44 (74.6%) were seropositive for T gondii and only 5 (8.5%) for N. caninum. Seropositivity for T gondii ranged from 0 to 100% in the seven different origin locals, with rates over 50% among the six zoos, whereas no positivity was found in the samples from ecological reserve. For N. caninum, seroprevalence varied from 0 to 50% in the different locals, with the highest rates also detected in zoos. Seroprevalence for T gondii was strongly related with age, with rates significantly higher among adult wolves (91.7%) when compared to newborn or young animals. Seropositive samples for N. caninum were found predominantly in adult wolves. For both parasites, seroprevalence did not show a significant distinction in relation to gender. Although seroprevalence for T gondii was significantly higher when compared to N. caninum in the Brazilian captive maned wolves tested, these findings reflect the great exposure of this species to T gondii and, in lower extension, to N. caninum. Also, the present study demonstrated for the first time the presence of antibodies to N. caninum in wild life from South America. (C) 2004 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The genetic and morphological variability among 15 Brazilian strains of Microcystis aeruginosa (Kütz.) Kütz. collected from four locations was examined and compared with several reference strains of M. aeruginosa, M. viridis (A. Br.) Lemm. and M. wesenbergii (Kom.) Kom. in Kondr. Brazilian strains were classified by morphological features and by comparison of the nucleotide sequences of the cpcBA intergenic spacer and flanking regions. Our results indicate that Brazilian strains classified as M. aeruginosa are phylogenetically diverse compared with reference strains of M. aeruginosa and that the current taxonomy underestimates genetic diversity within M. aeruginosa. The data also demonstrate that morphological criteria alone are inadequate to characterize Microcystis species. Although colonial characters were shown to vary considerably in culture, some genetic lineages demonstrated consistent cellular diameter ranges, indicating that cell size has value as a taxonomic character. The detection of six M. aeruginosa genotypes in a single water body indicates that morphological approaches can also seriously underestimate the diversity of Microcystis bloom populations.
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The objective of this study was to investigate the spatial and temporal distribution of Libinia spinosa H. MILNE EDWARDS 1834 on unconsolidated sublittoral bottoms in two regions off the northern coast of the state of São Paulo, and to analyze the influence of environmental factors on the occurrence of this species and observe the recruitment pattern of its young. Crabs were collected monthly (July 2001 through June 2003) at depths of 5, 10, 15, 20, 25, 30 and 35 In, from a fishing boat equipped with two double-rig nets. Samples of water and sediment were collected for analysis of environmental factors. A total of 2112 spider crabs was obtained (701 juveniles and 1411 adults). The highest abundance was observed at depths of 20 and 25 m, in both regions. These localities were characterized by substrate composed of very fine sand and silt-clay. In regard to the temporal distribution, juveniles and adults predominated in the summer and winter months respectively. From these results, one can infer that the distribution of L. spinosa is related to environmental factors favorable for its life cycle; sediment type is the factor which most strongly determines its presence. © E. Schweizerbart'sche Verlagsbuchhandlung (Nägele u. Obermiller), 2007.
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Recent reports on the prevalence of multiple sclerosis (MS) have described discrepancies between the rates in cities in the northeastern and southeastern regions of Brazil, representing a north-south gradient. European immigrants settled in southeastern and southern Brazil at the beginning of the twentieth century. In this study, we report the frequency of European ancestors among Brazilian MS patients in four cities in the southern and southeastern regions of Brazil. Methods: A total of 652 consecutive patients with confirmed MS diagnoses seen at four centers in Belo Horizonte, Ribeirão Preto, Londrina and Santos were asked about the origin of their ancestors, going back three generations. Results: 287 (44%) reported Italian ancestry, 211 (32%) reported that all ancestors were born in Brazil, 49 (7.5%) had Portuguese ancestry and 70 (10%) had Spanish ancestry. The patients in Belo Horizonte and Londrina reported higher proportions of Italian ancestry than the proportions estimated for the populations of their respective States. Conclusion: Brazil has a north-south gradient of 0.91/100,000 per degree of latitude, which is higher than the gradient for Latin America. Since the largest immigrant group that settled in southern and southeastern Brazil was from Italy, it is possible that Italian immigration was one of the factors that have contributed toward increasing the prevalence of MS in these regions. © 2013 Elsevier B.V. All rights reserved.
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The water column overlying the submerged aquatic vegetation (SAV) canopy presents difficulties when using remote sensing images for mapping such vegetation. Inherent and apparent water optical properties and its optically active components, which are commonly present in natural waters, in addition to the water column height over the canopy, and plant characteristics are some of the factors that affect the signal from SAV mainly due to its strong energy absorption in the near-infrared. By considering these interferences, a hypothesis was developed that the vegetation signal is better conserved and less absorbed by the water column in certain intervals of the visible region of the spectrum; as a consequence, it is possible to distinguish the SAV signal. To distinguish the signal from SAV, two types of classification approaches were selected. Both of these methods consider the hemispherical-conical reflectance factor (HCRF) spectrum shape, although one type was supervised and the other one was not. The first method adopts cluster analysis and uses the parameters of the band (absorption, asymmetry, height and width) obtained by continuum removal as the input of the classification. The spectral angle mapper (SAM) was adopted as the supervised classification approach. Both approaches tested different wavelength intervals in the visible and near-infrared spectra. It was demonstrated that the 585 to 685-nm interval, corresponding to the green, yellow and red wavelength bands, offered the best results in both classification approaches. However, SAM classification showed better results relative to cluster analysis and correctly separated all spectral curves with or without SAV. Based on this research, it can be concluded that it is possible to discriminate areas with and without SAV using remote sensing. © 2013 by the authors; licensee MDPI, Basel, Switzerland.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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To evaluate variations of some anatomic structures of sellar and parasellar regions and their possible differences between genders and age groups. Magnetic resonance images (MRI) of 380 patients were performed to analyze the dimensions of the sphenoid sinus, pituitary gland, optic chiasm, intra-cavernous carotid distances, distance between columella nasal - sphenoid sinus; and columella nasal-pituitary gland. The patients age ranged between 20 and 80 years (mean age 48 years). The study included 235 females (mean age 53 years) and 145 males (mean age 40 years). The transverse length of the pituitary, the inter-carotid distance and the height of the pituitary were similar between genders and age groups. The width and height of the optic chiasm showed differences only between females of different ages. Males presented greater distances between nasal columella and sphenoid sinus. The most common type of pneumatization of the sphenoid sinus was the sellar, and depending on the age group, sphenoid sinus was larger in males than females. The anatomy of the Sellar and parasellar regions is complex and varies widely within the normal range. They are a small area, rich in anatomical details affecting multiple physiological systems in the body and, therefore, have great importance in several medical fields. A better understanding of these complex structures is essential in clinical diagnosis and treatment of disease.