961 resultados para Upwelling Regime


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Based on samples with a 140-liter bottles in the upwelling region of the equatorial Pacific, an analysis was made of vertical distribution of various members of the plankton community of organisms (small and large phytoplankton, bacteria, different groups of protozoans, small and large, mainly herbivorous and predatory, animals). There is a distinct vertical divergence between layers of dominance of groups with similar feeding habits against the background of uneven quantitative distribution. Contrariwise, there are masses of consumers in the layers of high concentration of their potential prey.

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Feeding patterns of mass herbivorous copepods in upwelling areas are investigated. Daily rations and aspects of their formation are examined in Calanoides carinatus (Benguela upwelling), Calanus pacificus (off the California coast), and Calanus australis (Peru upwelling). Rations were calculated based on gut plant pigment contents obtained at daily stations using laser spectrofluorometry, experimental data on the rate of gut evacuation and data on the carbon/chlorophyll ratio in phytoplankton and particulate matter at the respective stations. When phytoplankton was abundant, diel feeding rhythms were not pronounced and gut pigment level was high during the entire 24-h period. When phytoplankton biomass was low, distinct feeding rhythms were pronounced with a nocturnal maximum. During active upwelling intensive feeding on phytoplankton supports energy (respiration) and plastic (growth, development, reproduction, accumulation of reserves) metabolism of copepods. When upwelling was inactive, the surface part of the population feeds less actively and is able only partially to cover its energy expenditures. The actively growing and reproducing populations of C. pacificus and C. carinatus may consume close to 20% of primary production, whereas the inactive population of C. australis consumed only 0.2% of primary production when upwelling weakened.

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O trabalho apresenta resultados de pesquisa acerca das políticas de educaçao no Brasil, do princípio regime de colaboraçao e da gestao da educaçao, apresentando, neste momento, aspectos da trajetória sociopolítica da elaboraçao ou adequaçao dos Planos Municipais de Educaçao (PMEs), deflagrada em 2013 pelo MEC/SASE, com as possibilidades de efetivaçao do regime de colaboraçao e da gestao democrática. Sua abordagem é qualitativa, de caráter teórico-empírico e exploratório, abarcando a documentaçao relativa aos PMEs dos Municípios. No Tocantins, até o início do ano de 2014, um georreferenciamento demonstra que dos 139 Municípios, apenas seis elaboraram seus PMEs. Neste contexto, predomina a visao de administraçao municipal restrita às suas instituiçoes escolares e ao tempo de sua gestao, sem relaçao ou articulaçao com metas nacionais comuns com vistas à materializaçao do Sistema Nacional de Educaçao. Deste processo, destaca-se o significativo movimento sociopolítico em torno do planejamento da educaçao no século XXI, enfrentado o desafio de definir o objetivo comum da educaçao brasileira. Entretanto, há ideias que merecem ser investigadas, como a sua concepçao de gestao e planejamento e as formas de colaboraçao estabelecidas

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ATP distribution in coastal waters off Peru was examined and was found to differ with hydrological conditions in this area; maximal values in the vicinity of an intense upwelling were the same in 1974 and 1978. ATP distribution was highly non-uniform in 1978, particularly in upper layers of the northern section, due to disruption of a community (dense patches of bloom), which began about 10-15 days before our observations, and also because of appearance of a red tide. Unusually intense microplankton metabolism was found in Peruvian waters, particularly in the lower layers of the northern section, where ATP concentration of 3.6 ?g/l were found. Values of live microplankton biomass presented.

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Porewater concentrations of sulfate, methane, and other relevant constituents were determined on four sediment cores from the high productivity upwelling area off Namibia which were recovered from the continental slope at water depths of 1300 and 2000 m. At all four stations a distinct sulfate-methane transition zone was observed several meters below the seafloor in which both sulfate and methane are consumed. Nutrient porewater concentration profiles do not show gradient slope changes at the depths of the transition zones. Flux calculations carried out on the basis of the determined porewater profiles revealed that anaerobic methane oxidation accounts for 100% of deep sulfate reduction within the sulfate-methane transition zone and consumes the total net diffusive sulfate flux. A significant contribution of organic carbon oxidation to the reduction of sulfate at these depths could, therefore, be excluded. We state that porewater profiles of sulfate with constant gradients above the transition zones are indicative for anaerobic methane oxidation controlling sulfate reduction.