41 resultados para Aluminium in Cochin estuary

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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O objetivo do presente estudo foi avaliar a utilização de conchas de gastrópodes por Clibanarius vittatus (Bosc, 1802), na Praia dos Pescadores, em São Vicente (SP), Brasil. Foram realizadas amostras mensais no período de maio de 2001 a abril de 2003, na região intertidal durante a maré baixa. Todos os animais foram pesados e tiveram o comprimento de seu escudo cefalotorácico mensurados, suas conchas identificadas e medidas quanto ao comprimento (mm), abertura (mm) e peso (g). Capturamos 2.344 ermitões (644 machos, 1.594 fêmeas não-ovígeras, 45 fêmeas ovígeras e 61 em intersexo), utilizando 13 espécies de conchas de gastrópodes, das quais Stramonita haemastoma (Linnaeus, 1767), Cymatium parthenopeum (Von Salis, 1793) e Achatina fulica (Bowdich, 1822) representaram mais de 98% das conchas utilizadas. Obteve-se significativa diferença de tamanho entre os sexos, com machos e indivíduos em intersexo atingindo maior porte físico do que fêmeas. Este padrão influenciou fortemente na ocupação e utilização de conchas, principalmente em A. fulica, que foi a maior concha obtida por C. vittatus, utilizada somente por machos e indivíduos em intersexo. Cymatium parthenopeum foi a única espécie de concha em que se obtiveram elevados coeficientes de determinação para todas os parâmetros analisados. Stramonita haemastoma apresentou elevados e significativos coeficientes de determinação, indicando que esta espécie é o principal recurso de concha ocupada na Praia dos Pescadores.

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Schools of mullets, Mugilidae, are abundant in estuaries and shallow marine waters. We report on the schooling behavior of juvenile white mullet, Mugil curema, in the estuary of the Canto da Paciência stream, in Ubatuba, southeastern Brazil. Schools of small fish (15 to 35 mm TL) were composed of a larger number of individuals (up to a hundred individuals), and were found feeding mainly in shallow nearshore waters, whereas schools of larger fish (40 to 100 mm TL) were observed only in deeper waters. Three patterns of swimming were observed for the schools: stationary feeding, slow movement while searching for food, and rapid displacement. The variations observed in school structure and behavior seem to be related to the balance between predation risk and increasing food intake. Copyright © 2007 Sociedade Brasileira de Ictiologia.

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An automatic Procedure with a high current-density anodic electrodissolution unit (HDAE) is proposed for the determination of aluminium, copper and zinc in non-ferroalloys by flame atonic absorption spectrometry, based on the direct solid analysis. It consists of solenoid valve-based commutation in a flow-injection system for on-line sample electro-dissolution and calibration with one multi-element standard, an electrolytic cell equipped with two electrodes (a silver needle acts as cathode, and sample as anode), and an intelligent unit. The latter is assembled in a PC-compatible microcomputer for instrument control, and far data acquisition and processing. General management of the process is achieved by use of software written in Pascal. Electrolyte compositions, flow rates, commutation times, applied current and electrolysis time mere investigated. A 0.5 mol l(-1) HNO3 solution was elected as electrolyte and 300 A/cm(2) as the continuous current pulse. The performance of the proposed system was evaluated by analysing aluminium in Al-allay samples, and copper/zinc in brass and bronze samples, respectively. The system handles about 50 samples per hour. Results are precise (R.S.D < 2%) and in agreement with those obtained by ICP-AES and spectrophotometry at a 95% confidence level.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The relative growth of U. thayeri was studied for a subtropical mangrove population in the estuary of the Comprido and Escuro rivers, Ubatuba, São Paulo State, Brazil. The evaluation of the morphological sexual maturity of U. thayeri was performed using the allometric technique. Remarkable ontogenetic changes were observed in the allometric growth of the male major cheliped and the female abdomen, indicating that these structures are closely connected to the timing of sexual maturity. For males, the relative-growth analysis of cheliped propodus length rendered an estimate of 13.8 mm of carapace width for the size at onset of sexual maturity. A distinct growth pattern was observed for the abdomen of U. thayeri females. It has a wide puberty size range (from 10.7 to 16.8 mm of CW) compared to other brachyurans previously studied. Thus, the females' abdominal growth can be represented by three growth phases: immature, transitional, and mature. The major cheliped is the fight one in 50% of males. The median length of the male major cheliped did not differ between right- and left-handed crabs.

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The objective of the present study was to characterize the spatial distribution and shell utilization of three hermit crab species in the estuarine-bay complex of São Vicente, São Paulo State, Brazil. Monthly samples were done throughout two years, in the non-consolidated sub-littoral at the estuarine-bay complex. The environmental factors, such as temperature, salinity and depth, were measured every month. The three hermit crab species, Clibanarius vittatus, Loxopagurus loxochelis and Isocheles sawayai, were captured utilizing shells from six gastropods species; 92.7% of the hermit crabs utilized Stramonita haemastoma. The results suggest a strong correlation between hermit crabs spatial distribution and salinity, which was considered the main environmental factor limiting their distribution in the estuary. I. sawayai was the only species present in all transects sampled; C. vittatus was captured only in regions with low salinity and L. loxochelis occurred only in high salinity waters.

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This paper is aiming to evaluate the effects of different levels of the aluminum on the growth of the Eucalyptus grandis x E. urophylla shoots cultivated in vitro. Evaluations were carried out on pH and chemicals modifications of the culture medium by Geochem program, polyamines contents (putrescine, espermidine e espermine) and acid phosphatase ativity on the shoots. The trial had a totally randomized design with four treatments and four replicates. The treatments were: 0.0, 6.75,13.50 and 27 mg.L -1 of AlCl 3.6H 2. Evaluations were carried out on the 4th, 8th, 12th, 16th, 20th, 24th and 28th day of culture. The addition of the aluminium, in all concentrations, affected the culture medium ionic equilibrium, the morphology of the shoots, reduced the pH on the medium, induced an increase in polyamines content and higher acid phosphatase activity.

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The abundance and ecological distribution of Acetes americanus and Peisos petrunkevitchi were investigated from July 2006 to June 2007, in Ubatuba, Brazil. Eight transects were identified and sampled monthly: six of these transects were located in Ubatuba bay, with depths reaching 21 m, and the other two transects were in estuarine environments. A total of 33,888 A. americanus shrimp were captured, with the majority coming from the shallower transects (up to 10 m). Conversely, 6,173 of the P. petrunkevitchi shrimps were captured in deeper areas (from 9 to 21 m). No individuals from either species were found in the estuary. The highest abundances obtained for both species were sampled during the summer. Canonical correlation analysis resulted in a coefficient value of 0.68 (P = 0.00). The abundance of both species was strongly correlated with depth. Variations in temperature and salinity values were also informative in predicting the seasonal presence of P. petrunkevitchi in deeper areas and A. americanus in the shallower areas of the bay. It is conceivable that the shrimp adjust their ecological distribution according to their intrinsic physiological limitations. © 2012 Marine Biological Association of the United Kingdom.

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