1000 resultados para CNPq
Resumo:
Estuarine hydrodynamics is a key factor in the definition of the filtering capacity of an estuary and results from the interaction of the processes that control the inlet morphodynamics and those that are acting in the mixing of the water in the estuary. The hydrodynamics and suspended sediment transport in the Camboriú estuary were assessed by two field campaigns conducted in 1998 that covered both neap and spring tide conditions. The period measured represents the estuarine hydrodynamics and sediment transport prior to the construction of the jetty in 2003 and provides important background information for the Camboriú estuary. Each field campaign covered two complete tidal cycles with hourly measurements of currents, salinity, suspended sediment concentration and water level. Results show that the Camboriú estuary is partially mixed with the vertical structure varying as a function of the tidal range and tidal phase. The dynamic estuarine structure can be balanced between the stabilizing effects generated by the vertical density gradient, which produces buoyancy and stratification flows, and the turbulent effects generated by the vertical velocity gradient that generates vertical mixing. The main sediment source for the water column are the bottom sediments, periodically resuspended by the tidal currents. The advective salt and suspended sediment transport was different between neap and spring tides, being more complex at spring tide. The river discharge term was important under both tidal conditions. The tidal correlation term was also important, being dominant in the suspended sediment transport during the spring tide. The gravitational circulation and Stokes drift played a secondary role in the estuarine transport processes.
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O objetivo do presente estudo é caracterizar a hidrodinâmica e o transporte de material particulado em suspensão (MPS) no estuário de Caravelas sob diferentes condições de maré e vazão fluvial. Foram realizadas quatro campanhas hidrográficas durante ciclos completos de maré, sendo em condições de maré de sizígia e quadratura, e durante os períodos seco e chuvoso. Dados de nível de água, velocidade e direção de correntes, salinidade, temperatura e turbidez foram obtidos em uma estação fixa próxima da desembocadura do estuário. A partir destes dados foram obtidos os transportes residuais de MPS e calculado os mecanismos de transporte. As maiores concentrações médias de material particulado em suspensão ocorreram em condições de sizígia. Em condições de maré de quadraturao transporte resultante de MPS foi com sentido estuário acima, porém de pequena intensidade. Em condições de sizígia o estuário é caracterizado por correntes mais intensas e assimétricas, com dominância de vazante. Durante a condição de sizígia o estuário pode atuar como importador ou exportador de MPS. O estuário do rio Caravelas foi classificado como bem misturado e fracamente estratificado. A hidrografia e o balanço sedimentar são principalmente modulados pela altura da marée o aporte de água doce é irrelevante.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The aim of this work was to generate an inventory of the data on radiocarbon datings obtained from sediments of the São Paulo Bight (southern Brazilian upper margin) and to analyze the data in terms of Late Quaternary sedimentary processes and sedimentation rates. A total of 238 radiocarbon datings from materials collected using differents ampling procedures was considered for this work. The sedimentation rates varied from less than 2 to 68 cm.kyr-1. The highest sedimentation rate values were found in a low-energy (ría type) coastal system as well as in the upwelling zones of Santa Catarina and Cabo Frio. The lowest rates were found on the outer shelf and upper slopes. Our results confirm the strong dependency of the shelf currents, with an emphasis to the terrigenous input from the Río de La Plata outflow which is transported via the Brazilian Coastal Current, as well as of the coupled Brazil Current - Intermediate Western Boundary Current (BC-IWBC) dynamics on the sedimentary processes. At least three indicators ofthe paleo sea level were found at 12200 yr BP (conventional radiocarbon age) (103 meters below sea level - mbsl),8300-8800 cal yr BP (13 mbsl) and 7700-8100 cal yr BP (6 mbsl).
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In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. This study aims to analyse the morpho-anatomy of underground systems of six species of Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner and Vernonia megapotamica Spreng.), to describe these structures and to verify the occurrence and origin of shoot buds, and to analyse the presence of reserve substances. Individuals sampled in Cerrado areas in São Paulo State showed thick underground bud-bearing organs, with adventitious or lateral roots and presence of fructans. Xylopodium was found in all studied species, except for Trixis nobilis, which had stem tuber. The presence of fructans as reserve, and the capacity of structures in the formation of buds indicate the potential of herbaceous species of Asteraceae in forming a viable bud bank for vegetation regeneration in the Brazilian Cerrado.
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A hydrodynamic characterization of the Itapocu river and Barra Velha lagoon estuarine system was carried out with the objective of evaluating how the current regime in this area is affected by astronomical and meteorological tides and the river discharge. Meteorological, water level and current velocity and direction data were gathered hourly during a twenty-day period, from 22-July until 10-August, 2004. Current meters were positioned at the inlet, at the entrance of the north and south lagoons and at the lower estuary of the river along with a tide gauge. The estuarine system showed distinct current behavior among the different sectors within the estuary, responding to the different forcings. The strongest currents were observed at the inlet while the weakest values were observed at the northern lagoon, a location that showed little dynamic. The general flow was ebb-dominated flux, in response to fluvial discharge, even during local wind water set-up event.
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Os níveis de mercúrio (Hg) total em cabelos estão diretamente relacionados à alimentação, particularmente ao consumo de peixes por populações costeiras com grande representação caiçara. No presente estudo foram avaliados os níveis de mercúrio total em cabelos de crianças com idade entre 4 e 12 anos, pertencente a três escolas públicas da cidade de Cananéia, São Paulo, Brasil. Os resultados obtidos (mediana e intervalo) para mercúrio total foram de: 0,04mg.kg-1 (0,01-0,77mg.kg-1), 0,39mg.kg-1 (< 0,01-3,33mg.kg-1) e 0,39mg.kg-1 (< 0,01-2,81mg.kg-1) considerando as escolas ES1, ES2 e ES3, respectivamente. Em geral, os valores encontrados estiveram bem abaixo do valor preconizado pela Organização Mundial da Saúde para uma população adulta não exposta ao mercúrio (2,0mg.kg-1). Os baixos valores observados e a inexistência de valores de referência para mercúrio total em cabelos de crianças brasileiras possibilitam a consideração desses valores como possível referência nacional em cabelos de populações costeiras, uma vez que foram obtidos em região de baixo impacto ambiental.
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Com o principal objetivo de fornecer ferramentas para auxiliar na implementação do manejo sustentável de peixes ornamentais na Reserva de Desenvolvimento Sustentável Amanã, Amazonas, foi realizado o estudo da biologia reprodutiva de Heros efasciatus Heckel, 1840, um ciclídeo com potencial ornamental e com poucos trabalhos sobre a sua biologia e ecologia, apesar de já ser comercializado em algumas regiões amazônicas. Coletas bimestrais foram realizadas de fevereiro de 2006 a janeiro de 2007 em dez igarapés contribuintes do Lago Amanã e Urini, sendo utilizados três aparelhos de pesca (rede de arrasto, rapiché e armadilha tipo matapi) e ainda galhadas artificiais nas amostragens realizadas próximas aos lagos. Foram capturados 140 exemplares de H. efasciatus, sendo 50 fêmeas, 42 machos, e 46 indivíduos cujo sexo não foi identificado devido ao pequeno tamanho. O tipo de crescimento encontrado foi isométrico, sendo que o maior indivíduo observado apresentava 174 mm e o menor 14 mm. Os resultados encontrados auxiliarão na adoção de medidas de manejo, como a determinação de tamanhos mínimos de captura, superiores aos tamanhos médios de maturação (97 mm para as fêmeas) e o estabelecimento de períodos de defeso durante a época de sua reprodução (outubro a janeiro). A pequena abundância de indivíduos da espécie, quando comparada com o total de exemplares capturados (apenas 0,07%) e a baixa fecundidade média, de 2502 ovócitos, indica que se deve trabalhar anualmente apenas com um pequeno número de indivíduos, a fim de garantir a continuidade do estoque.
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A catalogue is provided with the type material of four superfamilies of "Acalyptrate" (Conopoidea, Diopsoidea, Nerioidea and Tephritoidea) held in the collection of the Museu de Zoologia da Universidade de São Paulo (MZUSP), São Paulo, Brazil. Concerning the taxa dealt with herein, the Diptera collection of MZUSP held 77 holotypes, 4 "allotypes" and 194 paratypes. In this paper, information about data labels, preservation and missing structures of the type specimens is given.
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A new species of sand-dwelling catfish genus Pygidianops, P. amphioxus, is described from the Negro and lower Amazon basins. The new species differs from its three congeners in the elongate eel-like body, the short barbels, and the small caudal fin, continuous with the body, among other traits of internal anatomy. The absence of anal fin further distinguishes P. amphioxus from all other Pygidianops species except P. magoi and the presence of eyes from all except P. cuao. The new Pygidianops seems to be the sister species to P. magoi, the two species sharing a unique mesethmoid with a dorsally-bent tip lacking cornua, and a produced articular process in the palatine for the articulation with the neurocranium. Pygidianops amphioxus is a permanent and highly-specialized inhabitant of psammic environments. Additional characters are proposed as synapomorphies of Pygidianops, including a hypertrophied symphyseal joint and associated ligament in the lower jaw; an elongate, laterally-directed, process on the dorsal surface of the premaxilla; and a rotated lower jaw, where the surface normally facing laterally in other glanapterygines is instead directed ventrally. These and other characters are incorporated into a revised phylogenetic diagnosis of Pygidianops.
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The pupal case of Systropus (Systropus) nitidus Wiedemann reared from an unidentified tipical Limacodidae (Lepidoptera) cocoon is described and illustrated for the first time. Only species of Limacodidae are recorded as host of the immature stages of S. (Systropus). The geographical distribution of S. (Systropus) nitidus is restricted to Brazil, from Pará to Santa Catarina states. This is the first pupal case description and illustration of a Neotropical species of the subgenus Systropus.
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Two neotropical species of Toxophora Meigen, 1848 are redescribed (T. aurea Macquart, 1848 and T. leucon Séguy, 1930) and the male terminalia, female spermathecae, and the eggs are described and illustrated. Both species can be easily segregated from the other congeners by the following features: T. leucon: body covered with dark brown scales, longitudinal stripe formed by yellow scales on center of mesonotum, scutellum and abdomen, and abdomen slender; T. aurea: antenna with short dark brown scales, body covered with yellow scales and spots of dark brown scales with greenish reflex, wings without inter-radial vein, femora with yellow scales and without setae on males, and abdomen stout.
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The present catalogue lists the "dorylomorph" ant types (Aenictinae: Aenictus; Cerapachyinae: Acanthostichus and Cerapachys; Ecitoninae: Eciton, Labidus, Neivamyrmex and Nomamyrmex; and Leptanilloidinae: Asphinctanilloides and Leptanilloides) housed in the Formicidae collection of the Hymenoptera laboratory, Museu de Zoologia da Universidade de São Paulo (MZSP), Brazil. In total, the collection includes types of 141 nominal species, of which 56 are still valid. The majority of types of dorylomorph species in the MZSP collection are syntypes (67 species), but there are as well 13 species represented by holotypes only, 17 by holotypes and paratypes, 43 species by paratypes only, and one species by a paralectotype. We record the label information, condition of the specimens, nomenclatural changes, type status, and provide indexes of the listed taxa.
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This catalogue lists the type specimens of 37 species of Pseudomyrmecinae ants deposited in the Hymenoptera Formicidae collection of the Museu de Zoologia da Universidade de São Paulo, which holds types of the only two genera that occur in the Neotropics, Pseudomyrmex Lund and Myrcidris Ward. We record the label information, condition of the specimens, nomenclatural changes, type status, and provide an index of the listed taxa.
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The mature larva and pupa of Fulgeochlizus bruchi (Candèze, 1896) are described and illustrated. Bioluminescent patterns are also given. Comments, new data on the first instar larva and natural history data are presented. The first instar larvae differ from the mature larvae mainly in their chaetotaxy, which is sparse and more symmetrically distributed.