844 research outputs found

    Remediation of a mine soil with insoluble polyacrylate polymers enhances soil quality and plant growth

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    We investigated the effects of different application rates of insoluble hydrophilic polyacrylate polymers on plant growth and soil quality from a Pb-contaminated mine soil. The polymer increased the waterholding capacity of the soil from about 250 g ⁄ kg in unamended soil to almost 1000 g ⁄ kg in soil with 0.6% polymer. However, the capacity of the polymer to retain water decreased progressively, presumably as the polymer sorbed Pb. Growth of orchardgrass (Dactylis glomerata L. cv. Amba) was stimulated in the polymer-amended soil. The greatest accumulated biomass over four cuts was obtained in soil amended with 0.4% of polymer. After orchardgrass had been growing for 101 days, the amounts of CaCl2-extractable Pb present in the polymer-amended soil were 15–66% of those in the unamended soil, depending on polymer application rate. The number of bacteria culturable on agar enriched with ‘Nutrient’ and yeast extract, and the activities of dehydrogenase, phosphatase, b-glucosidase, protease and cellulase increased following polymer application. In contrast, urease activity was impaired by polymer application, presumably due to the presence of ammonium as a counter ion. Principal component analysis was used to compare the effects of the different rates of polymer application. Overall, the application of 0.2 or 0.4% polymer resulted in closer values for the indicators of soil quality used than the treatment with 0.6% polymer

    Identification of insulin in the tear film and insulin receptor and IGF-I receptor on the human ocular surface

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOInsulin produces pleiotropic effects on sensitive tissues. including the ocular surface, through the tyrosine kinase insulin receptor. Cerebrospinal fluid and secreted fluids, such as milk and saliva, have been reported to contain insulin. In the present study, the presence of insulin was examined in tear film, and the expression of insulin and insulin-like growth factor (IGF)-1 receptor was examined in the human cornea and conjunctiva. METHODS. Stimulated tear samples collected from 33 volunteers (17 men, 16 women), aged 23 to 51 years, who were fed or fasted for 12 hours, were assayed for total protein and insulin content by the biuret dye test and a radioimmunoassay, respectively. Frozen sections of human cornea (n = 4) and conjunctiva (n = 3) were incubated with anti-insulin receptor and anti-IGF-1 receptor antibodies and developed with a secondary antibody-peroxidase conjugate. RESULTS. Insulin was detected in all tear samples analyzed, the mean concentration being 0.404 +/- 0.129 ng/mL. There were no gender-related differences. In fed subjects, tears tended toward a higher insulin content than those in fasted individuals. There was no linear correlation between insulin and total protein content (mean, 4.61 +/- 0.79 mg/mL) in the tear film. Insulin and IGF-1 receptors were detected in the plasma membrane and cytoplasm of corneal and conjunctival epithelial cells. CONCLUSIONS. To the best of the authors' knowledge, this Study represents the first demonstration of insulin in human tear film and the presence of insulin and IGF-1 receptor on the human ocular surface. These results suggest that the pancreatic hormone may play a metabolic and/or mitogenic role on the ocular surfaceO TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE FEVEREIRO DE 2015.434963967FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOsem informaçãosem informaçãosem informaçã

    Evaluation of composts and liming materials in the phytostabilization of a mine soil using perennial ryegrass

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    A microcosm experiment was carried out to evaluate the effects of municipal solid waste compost (MSWC) or garden waste compost (GWC), and liming materials in the rehabilitation of a soil affected by mining activities, and to study the use of perennial ryegrass (Lolium perenne L.) for phystostabilization. The performance of the amendments was assessed by soil chemical parameters, total and bioavailable metals (Cu, Pb and Zn), soil enzymatic activities, and plant relative growth and mineral composition. In general, both composts corrected soil acidity and increased the total organic matter content of the soil, although with a better performance in the case of MSWC, especially when considering total N and available P and K levels in the amended soil. The application of both composts and liming materials led to a decrease in the mobile fractions of Cu, Pb and Zn, but mobilisable fractions of Cu and Zn increased with MSWC application. Plant biomass increased more than three times in the presence of 50 Mg MSWC ha−1 and with the combined use of 25 or 50 Mg MSWC ha−1 and CaO, but no significant differences were observed when GWC was applied. Plant tissue analysis showed that the treatments did not significantly reduce Cu, Pb and Zn uptake by the plant. Dehydrogenase, and the enzymes related to the N-cycle, urease and protease, had increased activities with increasing MSWC application rate. Conversely, the enzymatic activities of both enzymes related to the C-cycle, cellulase and ÎČ-glucosidase, were only positively affected by GWC application, a compost obtained from raw materials rich in C. Principal component analyses evidenced this clear separation between the effect of MSWC on soil enzymes related to the N-cycle and of GWC on soil enzymes related to the C-cycle. This study indicates that MSWC (50 Mg ha−1, limed or unlimed) can be used successfully in the remediation of a highly acidic metal-contaminated soil, allowing the establishment of perennial ryegrass

    Organic residues as immobilizing agents in aided phytostabilization: (I) Effects on soil chemical characteristics

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    A greenhouse experiment was conducted to evaluate the effect of three different organic residues, sewage sludge (SS), municipal solid waste compost (MSWC), and garden waste compost (GWC), as immobilizing agents in aided phytostabilization of a highly acidic metal-contaminated soil, affected by mining activities, using perennial ryegrass (Lolium perenne L.). The organic residues were applied at 25, 50 and 100 Mg ha 1 (dry weight basis), and their effects on soil chemical characteristics and on relative plant growth and metal concentrations were assessed. All the organic residues tested immobilized Cu, Pb and Zn, decreasing their mobile fractions. This was corroborated by negative correlations obtained between mobile Cu, Pb and Zn and other soil chemical characteristics, which rose as a consequence of the amendments applied (i.e., pH, electrical conductivity, organic matter, nitrogen content, available P and available K), and by the multivariate exploratory techniques performed that showed an inverse correlation between these groups of variables. The greatest increase in ryegrass relative growth (more than three times) was obtained in the presence of 50 Mg MSWC ha 1, followed by SS at the same application dosage. GWC did not contribute to an increase in shoot growth, due to its small capacity to correct soil acidity and to supply essential macronutrients (N, P, K). No extractant was able of demonstrating by a linear correlation the uptake of Cu, Pb and Zn by ryegrass. This plant was therefore not a good ‘‘indicator” of Cu, Pb and Zn availability in the soil. The results obtained in this study suggest that ryegrass can be used in aided phytostabilization for this type of mine contaminated soils and that MSWC, and to a minor extent SS, applied at 50 Mg ha 1, were effective in the in situ immobilization of metals, improving soil chemical properties and leading to a large increase in plant biomas

    Evaluation of tests to assess the quality of mine-contaminated soils

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    An acid metal-contaminated soil from the Aljustrel mining area (a pyrite mine located in SW Portugal in the Iberian Pyrite Belt) was subjected to chemical characterisation and total metal quantiWcation (Cd, Cr, Cu, Ni, Pb and Zn). Water-soluble metals were determined and a sequential extraction procedure was used to investigate metal speciation. Two bioavailable metal fractions were determined: a mobile fraction and a mobilisable fraction. Soil ecotoxicity was studied using a battery of bioassays: plant growth test and seed germination with cress (Lepidium sativum L.), earthworm (Eisenia fetida) mortality, E. fetida avoidance behaviour, luminescent inhibition of Vibrio Wscheri and Daphnia magna immobilisation. Although the total content of Cu, Zn and Pb in the soil was large (362, 245 and 1,250 mg/ kg dry matter, respectively), these metals were mostly structurally bound (87% for Cu, 81% for Zn and 89% for Pb) and, therefore, scarcely bioavailable. Nonetheless, the D. magna immobilization test using soil leachate showed an EC50 (48 h) of 36.3% (v/v), and the luminescent inhibition of V. Wscheri presented an EC20 (15 min) of 45.2% and an EC20 (30 min) of 10.7% (v/v), suggesting a considerable toxic eVect. In the direct exposure bioassays, E. fetida avoided the mine soil at the highest concentrations (50%, 75% and 100% v/v). At the same soil concentrations, cress showed negligible growth. The results suggest the need to use a battery of toxicity tests, in conjunction with chemical methods, in order to assess the quality of mine-contaminated soils correctly

    Malocclusion and dental appearance in underprivileged brazilian adolescents

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    Satisfaction with dental aesthetics is a subjective indicator used in epidemiological studies and is related to health behaviours. Little is known about the factors that influence this indicator, particularly among adolescents who live in a situation of social vulnerability. The aim of this study was to investigate the relationship between malocclusion and dental appearance in underprivileged Brazilian adolescents. This analytical cross-sectional study was conducted in Piracicaba, Brazil, and evaluated 884 adolescents from 13 to 19 years of age. The dependent variable was satisfaction with dental appearance, and the independent variables were classified as individual (components of the Dental Aesthetic Index - DAI, sex and age) and contextual (social exclusion index). For statistical analysis, multilevel regression models were estimated. The individual variables were considered Level 1, and the contextual variable was considered Level 2, with a level of significance of 5%. The mean age of the adolescents was 15.3 years. Female adolescents more frequently affirmed that they were satisfied with their dental appearance than did male individuals. There was an increase in dissatisfaction with oral health with the increase in anterior maxillary overjet, midline diastema, larger anterior irregularity in the maxilla, larger anterior irregularity in the mandible, anterior open bite and antero-posterior molar relation. Satisfaction with dental appearance was associated with individual factors such as sex and DAI components33CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ141654/2013-

    Antigenic typing of brazilian rabies virus samples isolated from animals and humans, 1989-2000

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    Animal and human rabies samples isolated between 1989 and 2000 were typified by means of a monoclonal antibody panel against the viral nucleoprotein. The panel had been previously established to study the molecular epidemiology of rabies virus in the Americas. Samples were isolated in the Diagnostic Laboratory of the Pasteur Institute and in other rabies diagnostic centers in Brazil. In addition to the fixed virus samples CVS-31/96-IP, preserved in mouse brain, and PV-BHK/97, preserved in cell culture, a total of 330 rabies virus samples were isolated from dogs, cats, cattle, horses, bats, sheep, goat, swine, foxes, marmosets, coati and humans. Six antigenic variants that were compatible with the pre-established monoclonal antibodies panel were defined: numbers 2 (dog), 3 (Desmodus rotundus), 4 (Tadarida brasiliensis), 5 (vampire bat from Venezuela), 6 (Lasiurus cinereus) and Lab (reacted to all used antibodies). Six unknown profiles, not compatible with the panel, were also found. Samples isolated from insectivore bats showed the greatest variability and the most commonly isolated variant was variant-3 (Desmodus rotundus). These findings may be related to the existence of multiple independent transmission cycles, involving different bat species.Amostras de vĂ­rus rĂĄbico isoladas de animais e humanos no perĂ­odo de 1989 a 2000 foram tipificadas antigenicamente com a utilização de um painel de anticorpos monoclonais contra a nucleoproteĂ­na viral, prĂ©-estabelecido para o estudo da epidemiologia molecular do vĂ­rus rĂĄbico isolado nas AmĂ©ricas. As amostras testadas foram isoladas no laboratĂłrio de diagnĂłstico do Instituto Pasteur e outros centros de diagnĂłstico de raiva no Brasil. AlĂ©m das cepas de vĂ­rus rĂĄbico fixo CVS-31/96-IP, mantida em cĂ©rebro de camundongos e a PV-BHK/97, mantida em cultura de cĂ©lulas, cepas de vĂ­rus rĂĄbico isoladas de cĂŁes, gatos, bovinos, eqĂŒinos, morcegos, ovinos, caprino, suĂ­nos, raposa, sagĂŒĂ­, coatĂ­, guaxinim e humanos, totalizaram 330 amostras. Seis variantes antigĂȘnicas foram definidas, compatĂ­veis com perfĂ­s observados no painel de anticorpos monoclonais prĂ©-estabelecido utilizado, as de nĂșmero 2 (cĂŁo), 3 (Desmodus rotundus), 4 (Tadarida brasiliensis), 5 (Vampiro da Venezuela), 6 (Lasiurus cinereus) e Lab (reagente a todos os anticorpos utilizados), alĂ©m de outros seis perfĂ­s desconhecidos, nĂŁo compatĂ­veis com aqueles observados no painel utilizado. A maior variabilidade foi observada entre as amostras isoladas de morcegos insetĂ­voros e a variante mais comum isolada entre as espĂ©cies foi a variante 3 (Desmodus rotundus). Estes fatos podem representar a existĂȘncia de mĂșltiplos ciclos de transmissĂŁo independentes, envolvendo diferentes espĂ©cies de morcegos
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