24 research outputs found

    Spatial distribution of the most abundant sea urchin populations on the southeast coast of São Paulo (Brazil)

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    Se investigó la variación espacial en la abundancia de Echinometra lucunter, Lytechinus variegatus y Arbacia lixula con respecto a cuatro escalas espaciales (105, 104, 103 y 102 m) y dos profundidades (0–3 y 3–8 m), a lo largo de 100 km del litoral de São Paulo (agosto a octubre de 1996). Echinometra lucunter fue la especie más abundante, prefiriendo los fondos más someros bajo el efecto del oleaje. Se identificó un gradiente en su abundancia, aumentando en dirección del suroeste al noreste. Arbacia lixula mostró el mismo gradiente, pero con una mayor abundancia en el sector más profundo. Ambas especies mostraron diferencias significativas a una escala espacial de centenares de metros y E. lucunter también a una escala de kilómetros. Lytechinus variegatus mostró un patrón en mosaico, siendo abundante en ciertos sitios. Las variaciones en la calidad del agua y en la heterogeneidad natural del hábitat podrían explicar de forma conjunta la distribución espacial de estas poblaciones.The spatial variability of Echinometra lucunter, Lytechinus variegatus and Arbacia lixula was studied in relation to four spatial scales (105, 104, 103 and 102 m) and two depths (0–3 and 3–8 m), along 100 km of the São Paulo coastline (August to October 1996). Echinometra lucunter was the most abundant species, with preference for shallow substrates subject to wave action. An abundance gradient was identified, increasing from southwest to northeast. Arbacia lixula showed the same pattern of spatial variation, but was more abundant in the deeper areas. Both species showed significant differences on a spatial scale of hundreds of meters, and E. lucunter also on a scale of kilometers. Lytechinus variegates presented a patchy distribution, being more abundant at certain sites. Variations in the water quality and natural heterogeneity of the habitat may explain the spatial distribution of these populations.El presente trabajo ha sido realizado gracias a dos becas INTERCAMPUS (1996–1997) concedidas por el Gobierno Español (Ministerio de Asuntos Exteriores) a PSJ para su estancia en el Laboratorio de Ecotoxicología (Brasil)

    Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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    Continuous exposure to microplastics does not cause physiological effects in the cultivated mussel Perna perna

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    The environmental impact of microplastics is a challenging theme, especially under realistic experimental conditions. We investigated physiological responses to 0.1-1.0 mu m PVC particles intake by the mussel Perna perna after a relative long-term exposure (90 days) at a less extreme concentration compared with previous studies (0.125 g/L). Microplastic intake was inferred by the presence of PVC in the feces of mussels, and physiological damages were assessed through ingestion rate, assimilation efficiency, growth rate, cellular and molecular biomarkers (lysosomal integrity, lipid peroxidation, and DNA damage), and condition index. All physiological responses showed nonsignificant effects of the microplastics on the exposed mussels. We suggest that, despite the experimental concentration of microplastics, mussels were able to acclimate to the exposure through their abilities for long-term recovery and tolerance to stresses. These data have positive implications for environmental health and in terms of human food resource because mussel farming is a worldwide practice that heavily relies on plastic materials, increasing the chances of microplastic exposure and mussels contamination

    Matching metal pollution with bioavailability, bioaccumulation and biomarkers response in fish (Centropomus parallelus) resident in neotropical estuaries

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    Two neotropical estuaries affected by different anthropogenic factors were studied. We report levels of metals and metalloids in water and sediment as well as their influence on genetic, biochemical and morphological biomarkers in the native fish Centropomus parallelus. Biomarkers reflected the fish health status. Multivariate statistics indicated both spatial and temporal changes in both water and sediment, which are linked to the elemental composition and health status of inhabitant fish, showing the biggest influence of surface water, followed by sediments and interstitial water. Bioaccumulation in fish muscle was useful to identify elements that were below detection limits in water, pointing out the risk of consuming fish exceeding allowance limits for some elements (As and Hg in this case). Multivariate statistics, including physical, chemical and biological issues, presents a suitable tool, integrating data from different origin allocated in the same estuary, which could be useful for future studies on estuarine systems.Fil: Souza, Iara C.. Universidade Federal do Sao Carlos; BrasilFil: Duarte, Ian D.. Universidade Federal do Espírito Santo; BrasilFil: Pimentel, Natieli Q.. Universidade Federal do Sao Carlos; BrasilFil: Rocha, Lívia D.. Universidade Federal do Espírito Santo; BrasilFil: Morozesk, Mariana. Universidade Federal do Espírito Santo; BrasilFil: Bonomo, Marina M.. Universidade Federal do Espírito Santo; BrasilFil: Azevedo, Vinicius C.. Universidade Federal do Sao Carlos; BrasilFil: Pereira, Camilo D.S.. Universidade Santa Cecília; BrasilFil: Monferran, Magdalena Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; ArgentinaFil: Milanez, Camilla R. D.. Universidade Federal do Espírito Santo; BrasilFil: Matsumoto, Silvia T.. Universidade Federal do Espírito Santo; BrasilFil: Wunderlin, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; ArgentinaFil: Fernandes, Marisa N.. Universidade Federal do Sao Carlos; Brasi

    ALICE Electromagnetic Calorimeter Technical Design Report

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    The ALICE Electromagnetic Calorimeter technical design is reported

    Coherent J/ψ photoproduction in ultra-peripheral Pb–Pb collisions at √sNN=2.76 TeV

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    The ALICE Collaboration has made the first measurement at the LHC of J/ψ photoproduction in ultra-peripheral Pb–Pb collisions at sNN=2.76 TeV. The J/ψ is identified via its dimuon decay in the forward rapidity region with the muon spectrometer for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 55 μb−1. The cross section for coherent J/ψ production in the rapidity interval −3.6<y<−2.6 is measured to be dσJ/ψcoh/dy=1.00±0.18(stat)−0.26+0.24(syst) mb. The result is compared to theoretical models for coherent J/ψ production and found to be in good agreement with those models which include nuclear gluon shadowing
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