847 resultados para 13077-062
Resumo:
We provide a compilation of downward fluxes (total mass, POC, PON, BSiO2, CaCO3, PIC and lithogenic/terrigenous fluxes) from over 6000 sediment trap measurements distributed in the Atlantic Ocean, from 30 degree North to 49 degree South, and covering the period 1982-2011. Data from the Mediterranean Sea are also included. Data were compiled from different sources: data repositories (BCO-DMO, PANGAEA), time series sites (BATS, CARIACO), published scientific papers and/or personal communications from PI's. All sources are specifed in the data set. Data from the World Ocean Atlas 2009 were extracted to provide each flux observation with contextual environmental data, such as temperature, salinity, oxygen (concentration, AOU and percentage saturation), nitrate, phosphate and silicate.
Resumo:
Downward particle flux was measured using sediment traps at various depths over the Porcupine Abyssal Plain (water depth ab. 4850 m) for prolonged periods from 1989 to 1999. A strong seasonal pattern of flux was evident reaching a maximum in mid-summer. The composition of the material changed with depth, reflecting the processes of remineralisation and dissolution as the material sank through the water column. However, there was surprisingly little seasonal variation in its composition to reflect changes in the biology of the euphotic zone. Currents at the site have a strong tidal component with speeds almost always less than 15 cm/sec. In the deeper part of the water column they tend to be northerly in direction, when averaged over periods of several months. A model of upper ocean biogeochemistry forced by meteorology was run for the decade in order to provide an estimate of flux at 3000 m depth. Agreement with measured organic carbon flux is good, both in terms of the timings of the annual peaks and in the integrated annual flux. Interannual variations in the integrated flux are of similar magnitude for both the model output and sediment trap measurements, but there is no significant relationship between these two sets of estimates. No long-term trend in flux is evident, either from the model, or from the measurements. During two spring/summer periods, the marine snow concentration in the water column was assessed by time-lapse photography and showed a strong peak at the start of the downward pulse of material at 3000 m. This emphasises the importance of large particles during periods of maximum flux and at the start of flux peaks. Time lapse photographs of the seabed show a seasonal cycle of coverage of phytodetrital material, in agreement with the model output both in terms of timing and magnitude of coverage prior to 1996. However, after a change in the structure of the benthic community in 1996 no phytodetritus was evident on the seabed. The model output shows only a single peak in flux each year, whereas the measured data usually indicated a double peak. It is concluded that the observed double peak may be a reflection of lowered sediment trap efficiency when flux is very high and is dominated by large marine snow particles. Resuspension into the trap 100 m above the seabed, when compared to the primary flux at 3000 m depth (1800 mab) was lower during periods of high primary flux probably because of a reduction in the height of resuspension when the material is fresh. At 2 mab, the picture is more complex with resuspension being enhanced during the periods of higher flux in 1997, which is consistent with this hypothesis. However there was rather little relationship to flux at 3000 m in 1998. At 3000 m depth, the Flux Stability Index (FSI), which provides a measure of the constancy of the seasonal cycle of flux, exhibited an inverse relationship with flux, such that the highest flux of organic carbon was recorded during the year with the greatest seasonal variation.
Resumo:
Razón cristiana y cultura contemporánea / Eduardo Briancesco -- La Recepción en la historia de la Iglesia / Carlos Castro -- Los antecedentes y las raíces filosóficas de las posmodernidad / Alfredo H. Zecca -- Salmo 22: Dios abandona y salva al pobre / Enzo Cortese -- Pensar la cuestión de Dios a partir del “argumento único” de San Anselmo / Ricardo O. Diez -- Crónica de la Facultad -- Tesis para el doctorado y disertaciones escritas para la licenciatura -- Notas bibliográficas -- Índice del tomo XXX
Resumo:
Debate na Subcomissão dos Municípios e Regiões da Assembleia Nacional Constituinte (ANC) não consegue estabelecer a duração do mandato para prefeitos. Arnaldo Martins(PMDB-RO) quer fixar na Subcomissão a duração do mandato dos prefeitos. Alexandre Puzyna (PMDB-SC) acredita que ainda não é o momento de estabelecer o período do mandato dos prefeitos. Na Subcomissão da Política Agrícola e Fundiária e da Reforma Agrária, onze constituintes reprovam o relatório apresentado, ao tratar da Reforma Agrária. Dizem que a propriedade privada não pode ser limitada como quer o relatório de Oswaldo Lima Filho (PMDB-PE), que propõe o limite máximo de cem módulos. Cardoso Alves (PMDB-SP) é contra o limite de terras. Rosa Prata (PMDB-MG) apresenta contraproposta sem impor limites ao tamanho das terras. Alisson Paulinelli (PFL-MG) está de acordo com a proposta de Rosa Prata. Amaury Muller (PDT-RS) defende o estabelecimento de limites para as propriedades rurais. Aldo Arantes (PC do B-GO) afirma que o abastecimento de alimentos no Brasil é feito por pequenas propriedades e apoia o estabelecimento de terras de acordo com cada região do país. Oito Subcomissões votam os anteprojetos, entre elas a Subcomissão de Saúde, Seguridade e Meio Ambiente. Essa Subcomissão recebeu mais de trezentas emendas, as duas mais importantes, como explica José Elias Murad (PTB-SP), tratam da estatização do serviço de saúde e da proibição das propagandas de tabaco e bebidas alcoólicas.
Resumo:
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