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| Registros recuperados: 61 | |
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| Valladares,Gustavo Souza; Camargo,Otávio Antônio de; Carvalho,José Ruy Porto de; Silva,Alessandra Maria Cia. |
| Agricultural management with chemicals may contaminate the soil with heavy metals. The objective of this study was to apply Principal Component Analysis and geoprocessing techniques to identify the origin of the metals Cu, Fe, Mn, Zn, Ni, Pb, Cr and Cd as potential contaminants of agricultural soils. The study was developed in an area of vineyard cultivation in the State of São Paulo, Brazil. Soil samples were collected and GPS located under different uses and coverings. The metal concentrations in the soils were determined using the DTPA method. The Cu and Zn content was considered high in most of the samples, and was larger in the areas cultivated with vineyards that had been under the application of fungicides for several decades. The concentrations of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: PCA; GIS; Soil pollution; Copper; Zinc. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000300011 |
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| Sarto,Marcos Vinicius Mansano; Steiner,Fábio; Lana,Maria do Carmo. |
| In Brazil, plant-available micronutrients in the soil can be determined by several chemical extractants, the most common of which are dilute acid and chelating solutions. The purpose of this study was to assess the extractants 0.1 mol L-1 HCl, Mehlich-1, Mehlich-3 and DTPA for analysis of the micronutrients Cu, Zn, Fe, and Mn in soils from the state of Paraná. In samples from 12 soils (0-20 cm layer), wheat was planted (Triticum aestivum), grown for 42 days after emergence, and then bean (Phaseolus vulgaris) for 38 days. At the end of each planting period, the soil was sampled again. All extractants tested to assess the availability of Cu, Zn, Fe, and Mn correlated with each other. The efficiency of the extractants HCl, Mehlich-3 and DTPA in assessing... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil analysis; Correlation; Copper; Zinc; Iron; Manganese. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000600024 |
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| Gamain, Perrine; Feurtet-mazel, Agnes; Maury-brachet, Regine; Auby, Isabelle; Pierron, Fabien; Belles, Angel; Budzinski, Helene; Daffe, Guillemine; Gonzalez, Patrice. |
| Dwarf eelgrasses (Zostera noltei) populations have decreased since 2005 in Arcachon Bay (southwest France). Various stressors have been pointed out, however the role of xenobiotics like pesticides or copper (Cu) and of parameters like water temperature warming have not yet been explored. To determine their impact, Z. noltei individuals were collected in a pollution-free site and transferred to the laboratory in seawater microcosms. This dwarf eelgrass was exposed to a pesticide cocktail and copper, alone or simultaneously, at temperatures (10 °C, 20 °C, 28 °C) representative of different seasons. After a two-week contamination, leaf growth, leaf bioaccumulation of Cu, and differential expression of target genes were studied. Eelgrasses bioaccumulated Cu... |
| Tipo: Text |
Palavras-chave: Zostera noltei; Arcachon Bay; Pesticides; Copper; Cellular impacts. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00407/51831/58536.pdf |
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| Choudhary,Sikander P.; Bhardwaj,Renu; Gupta,Bishan D.; Dutt,Prabhu; Gupta,Rajinder K.; Kanwar,Mukesh; Dutt,Pitamber. |
| The present study determined the effects of copper and chromium metals on the endogenous titers of polyamines, auxins, abscisic acid and antioxidative enzyme activities in Raphanus sativus L. cv. Pusa chetki seedlings. Among polyamines, putrescine and spermidine contents were enhanced by Cu2+ metal to 62.44 and 402.8 µg g-1 f.w. respectively over control. Spermine which was not observed in control was recorded in highest concentration (1287.9 µg g-1 f.w.) in Cu2+ metal stressed seedlings. On the other hand Cr6+ metal treated seedlings showed reduced contents of putrescine (1.43 µg g-1 f.w.), cadaverine (0.09 µg g-1 f.w.), spermidine (277.99 µg g-1 f.w.) and spermine (2.29 µg g-1 f.w.) when compared to control and Cu2+ metal treated seedlings. Significant... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Catalase; Chromium; Copper; Guaiacol peroxidase; Polyamines (PAs); Superoxide dismutase. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400006 |
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| Dupraz, Valentin; Stachowski-haberkorn, Sabine; Menard, Dominique; Limon, Gwendolina; Akcha, Farida; Budzinski, Helene; Cedergreen, Nina. |
| The toxicity of the antifouling compounds diuron, irgarol, zinc pyrithione (ZnPT), copper pyrithione (CuPT) and copper was tested on the three marine microalgae Tisochrysis lutea, Skeletonema marinoi and Tetraselmis suecica. Toxicity tests based on the inhibition of growth rate after 96-h exposure were run using microplates. Chemical analyses were performed to validate the exposure concentrations and the stability of the compounds under test conditions. Single chemicals exhibited varying toxicity depending on the species, irgarol being the most toxic chemical and Cu the least toxic. Selected binary mixtures were tested and the resulting interactions were analyzed using two distinct concentration-response surface models: one using the concentration addition... |
| Tipo: Text |
Palavras-chave: Diuron; Irgarol; Pyrithione; Copper; Microbial ecotoxicology; Mixture model. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55695/57362.pdf |
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| Cervantes Gómez, Daniel. |
| El cobre (Cu) es un micromineral que cumple funciones esenciales en el organismo de los animales; del mismo modo es necesario para las bacterias ruminales, implicando que todos los nutrientes que requieren los microrganismos, dentro de estos el cobre, deben estar disponibles en el rumen en forma estable y continúa para asegurar su crecimiento. Por lo anterior, en el presente estudio se desarrollaron dos ensayos experimentales para determinar la concentración óptima y tóxica de cobre, con base al crecimiento y la actividad de las bacterias ruminales; en el primer experimento se utilizaron seis concentraciones de cobre (0, 10, 20, 30, 40 y 50 ppm), en un medio de cultivo que contenía heno de alfalfa. Los resultados de este ensayo mostraron que las... |
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Palavras-chave: Cobre; Concentración óptima y tóxica; Bacterias ruminales; Digestibilidad in vitro; Copper; Optimal and toxic concentration; Ruminal microbes; In vitro digestibility; Ganadería; Maestría. |
| Ano: 2012 |
URL: http://hdl.handle.net/10521/774 |
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| Lofgren, Hans; Robinson, Sherman; Thurlow, James. |
| Zambia's strong dependence on copper exports has suppressed other tradables sectors, indicative of a Dutch disease phenomenon. The current copper crisis will have strong economic effects, possibly reversing such Dutch disease effects. We use a computable general equilibrium model built around a 1995 social accounting matrix to simulate the short- and long-run effects of two scenarios that reflect the current crisis, a 20 percent reduction in world copper prices and a complete collapse of copper mining. Compared to the short run, the long run is characterized by more flexibility in production technology and capital allocation. Both scenarios require a significant reduction in the "non-copper" trade deficit, absorption, and household consumption. The... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Zambia; Copper; Structural adjustment; Agriculture; General equilibrium; International Development; C68; O55; Q17; Q32. |
| Ano: 2003 |
URL: http://purl.umn.edu/25805 |
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| Sussarellu, Rossana; Lebreton, Morgane; Rouxel, Julien; Akcha, Farida; Riviere, Guillaume. |
| Copper contamination is widespread along coastal areas and exerts adverse effects on marine organisms such as mollusks. In the Pacific oyster, copper induces severe developmental abnormalities during early life stages; however, the underlying molecular mechanisms are largely unknown. This study aims to better understand whether the embryotoxic effects of copper in Crassostrea gigas could be mediated by alterations in gene expression, and the putative role of DNA methylation, which is known to contribute to gene regulation in early embryo development. For that purpose, oyster embryos were exposed to 4 nominal copper concentrations (0.1, 1, 10 and 20 μg L−1 Cu2+) during early development assays. Embryotoxicity was monitored through the oyster embryo-larval... |
| Tipo: Text |
Palavras-chave: Oyster; Embryotoxicity; Copper; Gene expression; DNA methylation. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00417/52856/53756.pdf |
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| Souza,Patrícia Mendes de; Marinho,Petrusk Homero; Lima,Marcos Antônio Barbosa de; Nascimento,Aline Elesbão do; Takaki,Galba Maria de Campos. |
| The aim of this work was to evaluate the physiological aspects of polyphosphate metabolism of Cunninghamella elegans grown in presence of copper. The growth profile was obtained by means of biomass yields, orthophosphate consumption, polyphosphate accumulation and phosphatases activities. The results revealed the influence of copper on the growth, observed by biomass yields. Orthophosphate consumption was faster in cells grown in the presence of copper. The presence of copper in the culture medium induced polyphosphate accumulation. The polyphosphate level was almost constant in the beginning of control culture growth, and could be related to the exponential growth phase. On the other hand, the copper treated cultures exhibited a significant reduction in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cunninghamella elegans; Copper; Polyphosphate; Phosphatases. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822005000400002 |
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| Registros recuperados: 61 | |
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