547 research outputs found

    Scale of Auditory Behaviors e testes auditivos comportamentais para avaliação do processamento auditivo em crianças falantes do português europeu

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    PURPOSE: The objective of this research was to assess the auditory abilities of Portuguese children and compare such abilities to the score of the Scale of Auditory Behaviors (SAB). METHODS: Fifty-one children were evaluated with audiometry, speech audiometry, acoustic immittance measures, and eight behavioral tests involving dichotic listening, monotic listening, temporal processing, and sound localization. Their parents filled in the SAB questionnaire adapted to European A. SAB scores and auditory tests scores were submitted to Pearson's correlation coefficient. RESULTS: There is significant correlation between the score on SAB questionnaire and the auditory processing tests. The greatest coefficient was observed in temporal processing test (p=0.000). CONCLUSION: There was correlation between the score of SAB and the performance in auditory processing tests, suggesting that the SAB may be used for auditory processing screening.OBJETIVO: Investigar as habilidades auditivas de crianças portuguesas e verificar se há correlação entre aquelas e o escore do Scale of Auditory Behaviors (SAB). MÉTODOS: Todas as crianças foram submetidas a audiometria tonal, logoaudiometria, medidas de imitância acústica e oito testes comportamentais do processamento auditivo, envolvendo tarefas de escuta dicótica, escuta monótica, processamento temporal e localização sonora. Os pais das 51 crianças portuguesas avaliadas preencheram o questionário SAB adaptado ao português europeu. Foram calculados os valores do coeficiente de correlação de Pearson entre os escores obtidos no questionário e os dos testes do processamento auditivo. RESULTADOS: Observou-se correlação significativa entre o escore do questionário e o dos testes comportamentais, tendo a maior sido observada nos testes relacionados ao processamento temporal (p=0,000). CONCLUSÃO: Houve correlação entre o escore da SAB e os resultados obtidos nos testes auditivos comportamentais em crianças portuguesas, sugerindo que este questionário pode ser utilizado em triagem do processamento auditivo.CIEC – Research Centre on Child Studies, UM (FCT R&D 317

    Biological decolorization of xanthene dyes by anaerobic granular biomass

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    Biodegradation of a xanthene dyes was investigated for the first time using anaerobic granular sludge. On a first screening, biomass was able to decolorize, at different extents, six azo dye solutions: acid orange 7, direct black 19, direct blue 71, mordant yellow 10, reactive red 2 and reactive red 120 and two xanthene dyes—Erythrosine B and Eosin Y. Biomass concentration, type of electron donor, induction of biomass with dye and mediation with activated carbon (AC) were variables studied for Erythrosine B (Ery) as model dye. Maximum color removal efficiency was achieved with 4.71 g VSS L−1, while the process rates were independent of the biomass concentration above 1.89 g VSS L−1. No considerable effects were observed when different substrates were used as electron donors (VFA, glucose or lactose). Addition of Ery in the incubation period of biomass led to a fivefold increase of the decolorization rate. The rate of Ery decolorization almost duplicated in the presence of commercial AC (0.1 g L−1 AC0). Using different modified AC samples (from the treatment of AC0), a threefold higher rate was obtained with the most basic one, \textAC\textH2ACH2, as compared with non-mediated reaction. Higher rates were obtained at pH 6.0. Chemical reduction using Na2S confirmed the recalcitrant nature of this dye. The results attest that decolorization of Ery is essentially due to enzymatic and adsorption phenomena.This work was supported by the PTDC/AMB/69335/2006 project grants (Fundacao para a Ciencia e Technologia, FCT, Portugal), BRAIN project (ID 6681, European Social Found and Romanian Government and the grant of the Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-II-ID-PCE-2011-3-0559, Contract 265/2011

    Effects of iron-ore mining and processing on metal bioavailability in a tropical coastal lagoon

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    In water systems, water quality and geochemical properties of sediments determine the speciation of trace metals, metal transport, and sediment-water exchange, influencing metal availability and its potential effects on biota. Studies from temperate climates have shown that iron-ore mining and tailing wastewaters, besides being a source of trace metals, usually show high levels of dissolved ions and particulate suspended matter, thus having the potential of indirectly changing metal bioavailability. For the first time in the tropics, we identified the effects of iron-ore mining and processing on metal bioavailability in a coastal lagoon. With an extensive sampling scheme, we investigated the potential sources of metals; the links among metal levels in water, sediments, and invertebrates; and the contrasting effects on metal speciation and bioavailability. The metals Fe, Mn, Al, Cr, Zn, Cu, Ni, Pb, Cd, Hg, and As were measured in water, sediments (surface and profiles), and invertebrates from Mãe-Bá Lagoon and in the sites directly influenced by the mining operations (tailing dams and nearby rivers). In addition, samples from two other lagoons, considered pristine, were analyzed. The study area is located in the southeast of Brazil (Iron Quadrangle Region and a coastal area of Espírito Santo State). General water characteristics included pH, dissolved organic carbon, alkalinity, and anion composition. Water metal speciation was assessed by a speciation model (Chemical Equilibria in Aquatic Systems). Grain-size distribution, organic carbon, carbonate, and acid volatile sulfide (AVS) were determined in sediments. Statistical methods included comparison of means by Mann-Whitney test, ordination and correlation analyses, and analysis of regression for geochemical normalization of metals with grain size. The dissolved metal concentrations, the total metal levels in sediments, and the normalization based on the fine sediment fraction showed that the mining operations constitute potential sources of Fe, Mn, Cr, Cu, Ni, Pb, As, and Hg to Mãe-Bá Lagoon. However, trace metal availability was reduced because of increased pH, hardness, and sulfide content (356 μmol/g) in the sites influenced by the mining. The lagoon showed similar water chemistry as in the mining sites, with metal bioavailability further decreased by the presence of dissolved organic carbon and chloride. Although AVS levels in the lagoon were low (0.48-56 μmol/g), metal bioavailability was reduced because of the presence of organic matter. Metal levels in invertebrates confirmed the predicted low metal bioavailability in Mãe-Bá Lagoon. The lagoon was considered moderately contaminated only by Hg and As. The iron-ore mining and processing studied here constitute potential sources of metal pollution into the tropical lagoon. Contrary to expectations, however, it also contributes to reducing the overall metal bioavailability in the lagoon. These findings are believed to be useful for evaluating metal exposure in a more integrated way, identifying not only the sources of pollution but also how they can affect the components involved in metal speciation and bioavailability in water systems, leading to new insights
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