Trace element nutrition in the tropical zebu cattle type : lessons from the Gilgel Gibe catchment, Ethiopia

In the tropics, cattle are majorly dependent on natural pastures growing on poor soils and as a result prone to trace element deficiencies. This work investigated several aspects of trace element nutrition in zebu (Bos indicus) cattle, the most widely used cattle type in the tropics. Through several trials conducted at the Gilgel Gibe catchment, Ethiopia, we aimed to study factors influencing the flow of trace elements from soil to plant and grazing zebu cattle, and to investigate the impact of trace element status on health, production and trace elements in animal products. Overall, trace element, e.g., Cu, deficiencies were widely prevalent. Environment and certain grazing strategies were intimately related and affected trace element supply whereas cattle type affected trace element status. The effect of trace element status on trace elements in animal products was obvious, whereas the impact on health and production was less clear-cut. Key words: trace elements, minerals, cattle, zebu, Bos indicus, Ethiopia, tropic

Potential effects of environmental change on mining wastes in a hyperarid climate

Three desert washes were sampled to evaluate the transport of contaminated sediments from abandoned mining sites to downwash environments. The area of concern is an extreme arid climate considered stable and not to pose pathways for contaminated sediments to impact downwash environments. Research of mine wastes in Nelson, Nevada has shown that residual geogenic and anthropogenic trace elements have been mobilized in surface sediments as a result of storm event. Cyanide and trace elements, especially mercury and lead, have transported to 6000 m downwash from source areas. Short term environmental impacts appear to be minimal because of present-day environmental conditions. However, climate shifts caused by the El Nino Southern Oscillations or even a dramatic climate shift might increase regional precipitation promoting a more rapid erosion of contaminated sediment. Currently, wash sediments do not contain levels of CN- or trace elements that pose threats to the environment; however, if erosion and transport of mining waste increased because of additional precipitation, then CN- and trace elements loading in storm water would increase, with their possibly delivery to Lake Mohave

Distribution of trace elements and total organic carbon in surface sediments of the Sulu and Sulawesi Seas (Taburan Unsur Surih dan Organik Karbon di permukaan sedimen di Laut Sulu dan Sulawesi)

The concentrations of TOC, Al, Fe, Mn, Pb, Cu, Ni, Co and Cr in 27 surface sediments have been determined from the Sulu and Sulawesi Sesa during the ‘Saintifik Perdana 2009’ expedition cruise from 18 June to 1 August 2009. Sampling was conducted to elucidate concentrations and spatial distributions throughout the study area. The samples were digested using a total digestion technique and the concentrations were determined using the ICP-MS. The distribution of trace elements fluctuated with stations and water depth, but showed high metal concentrations in some locations such as Marudu Bay, Sandakan and Darvel Bay. The concentrations of trace elements were mostly lower than the earth’s mean crust and the world’s mean sediments with the exception of a few trace elements in certain stations. The Geoaccumulation Index (Igeo) was calculated and the results showed that Ni are in class 1 (unpolluted to moderately polluted) while other trace elements are considered unpolluted. It can therefore be concluded that the Sulu and Sulawesi Seas are unpolluted and pristin

Leaching of Trace Elements in Enugu Coal: Effect of Acid Concentration

The effect of acid concentration on the trace elements composition of Enugu sub-bituminous coal from Onyeama Mine was investigated by leaching the coal using nitric acid (HNO3) of 0.5M, 1.0M, 1.5M and 2.0M concentrations. The amount of trace elements (in ppm) present in the filtrate from the leaching process were determined using Varian AA240 Atomic Absorption Spectrophotometer with cathode lamps of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), and lead (Pb). Optimum leaching condition of the trace metals were obtained using 2.0M HNO3 solution for 1 hour and 75µm particle size which resulted in the detection of As(1.363ppm), Cu (1.413ppm), Cr (0.764ppm), Cd (0.146), and Pb (1.942ppm). 2.0M concentration of nitric acid has proven to be very effective in the leaching of trace metals in Enugu coal. Result of the SEM analysis shows that the porosity of the coal residue was increased and this provides strong evidence that significant amounts of inorganic elements were removed. Onyeama coal, therefore, contains large proportions of silica, calcium carbonate, and dolomite, as well as some elements such as aluminum, iron, and potassium, and other trace metals such as lead, chromium, cadmium, arsenic, mercury, copper

Radiative transfer in stellar atmospheres

This review presents basic equations for the solution of the NLTE radiative transfer problem for trace elements and methods for its solution are summarized. The importance of frequency coupling in radiative transfer in stellar atmospheres is emphasized.Comment: presented at the workshop held in Nice, France, 30.7.-4.8.2007, to appear in Non-LTE Line Formation for Trace Elements in Stellar Atmospheres, R. Monier et al. eds., EAS Publ. Se

Statistical equilibrium equations for trace elements in stellar atmospheres

The conditions of thermodynamic equilibrium, local thermodynamic equilibrium, and statistical equilibrium are discussed in detail. The equations of statistical equilibrium and the supplementary equations are shown together with the expressions for radiative and collisional rates with the emphasize on the solution for trace elements.Comment: presented at the workshop held in Nice, France, 30.7.-4.8.2007, to appear in Non-LTE Line Formation for Trace Elements in Stellar Atmospheres, R. Monier et al. eds., EAS Publ.Se

Trace elements accumulation in the sea lamprey along the major hydrographic basins of Portugal

Trace elements accumulation in the sea lamprey along the major hydrographic basins of Portuga

Determination of trace elements

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