39 research outputs found

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Overview of the JET results in support to ITER

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    Determination Of Total As And Inorganic Arsenic Species For The Environmental Quality Monitoring Of Groundwaters [estudo Da Especiação De ArsĂȘnio InorgĂąnico E Determinação De ArsĂ©nio Total No Monitoramento Ambiental Da Qualidade De ĂĄguas SubterrĂąneas]

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    This work reports an alternative, fast and robust method, for the determination of total As As(III) and As(V) by HG-AAS without the use of prereductants. The method is based on the different rates of arsine formation of the inorganic As species and the effect of As(III) in the signal obtained for total As. Groundwater and mineral spiked waters were used to sample preservation evaluation. The method was validated by the determination of As in SRM 1640 and used in the determination of total As and its inorganic species in groundwater samples collected from mines in the Iron Quadrangle - MG.324970975Irgolic, K.J., (1994) Em Arsenic: Exposure and Health, , Chappell, W. R.Abernathy, C. O.Cothern, C. R., eds.Science and Technology Letters: NorthwoodCullen, W.R., Reimer, K.J., (1989) Chem.Rev., 89, p. 713Vink, B.W., (1996) Chem. Geol., 130, p. 21Chatterjee, A., Das, D., Mandal, B.K., Chowdhury, T.R., Samanta, G., Chakraborti, D., (1995) Analyst, 120, p. 643Hsu, K.H., Froines, J.R., Chen, G.J., (1997) Em Arsenic Exposure and Health Effects, , Abernathy, C. O.Calderon, R. L.Chappell, W. R., eds.Chapman & Hall: New York, cap. 16Mabuchi, K., Lilienfeld, A.M., Snell, L.M., (1979) Arch. Environ. Health, 34, p. 312Thompson, D.J., (1993) Chem. Biol. Interact., 88, p. 89Barra, C.M., Santelli, R.E., Abrão, J.J., De La Guardia, M., (2000) Quim. Nova, 23, p. 58Hung, D.Q., Nekarassova, O., Compton, R.G., (2004) Talanta, 64, p. 269Carrero, P., Malavé, A., Burguera, J.L., Burguera, M., Rondón, C., (2001) Anal. Chim. Acta, 438, p. 195Chraim, H., Brindle, I.A., Le, X., (1992) Anal. Chem., 64, p. 667Shraim, A., Chiswell, B., Olszowy, H., (1999) Talanta, 50, p. 1109Clark, I., Fritz, P., (1997) Environmental Isotopes in Hydrogeology, , Lewis: New YorkBorba, R.P., Figueiredo, B.R., Rawllins, B.G., Matchullat, J., (2003) Environ. Geol., 44, p. 39Figueiredo, B.R., Borba, R.P., Angélica, R.S., (2007) Environ. Geochem. Health, 29, p. 109Smith, A.E., (1975) Analyst, 100, p. 300Burguera, M., Burguera, J.L., (1977) Talanta, 44, p. 1581Le, X.C., Cullen, W.R., Reimer, K.J., (1994) Anal. Chim. Acta, 285, p. 277Miller, J.N., Miller, J.C., (2000) Statistics and Chemometrics for Analtytical Chemistry, 4th Ed., , Prentice Hall: DorchesterAggett, J., Kriegman, M.R., (1987) Analyst, 112, p. 153Yokoyama, T., Takahashi, Y., Tarutani, T., (1993) Chem. Geol., 103, p. 103Driehaus, W., Seith, R., Jekel, M., (1995) Water Res., 29, p. 297Jekel, M.R., (1994) Em Arsenic in Environment, Part 1: Cycling and Characterization, , Nriagu, J. O., edJohn Wiley: New York, cap.6Oscarson, D.W., Huang, P.M., Defosse, C., Herbillon, A., (1981) Nature, 291, p. 5
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