243 research outputs found

    Water isotope technology application for sustainable eco-environmental construction: Effects of landscape characteristics on water yield in the alpine headwater catchments of Tibetan Plateau for sustainable eco-environmental construction

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    Topography-climate-vegetation-runoff relationships are important issues in hydrological studies. In this paper, based on analyzing water isotope characteristics of river water, the influence of these variables on the relative contribution of rain to river water was investigated during one rain event in the Heishui Valley of the upper Yangtze River in China. During one rain event on August 19, 2005, a total number of 182 river water samples were collected at 13 sampling sites located along the principal river course and its tributaries. The analysis of water isotopes in the principal river course and its tributaries showed that new rain water and secondary evaporation precipitation caused great variation in values of delta D and high d-excess increased with altitude. Based on calculations of two-component hydrograph separation using delta O-18, the results showed that the biggest relative contribution of new rain to river water (43%) was found in tributary B, while the smallest contribution (less than 5%) was found in tributary I. According to stepwise linear regression analysis, topography (elevation and slope) was the most important factor affecting the contributions of new rain to river water. When only vegetation variables were considered in the regression model, alpine shrub coverage proved to be negatively correlated with the contributions of new rain to river water, while alpine meadow coverage was positively correlated with the contributions of new rain. This would imply that increasing the relative coverage of alpine shrubs in this mountainous region of China may decrease the risk of flooding. (C) 2014 Elsevier B.V. All rights reserved

    Analysis of urinary oligosaccharides in lysosomal storage disorders by capillary high-performance anion-exchange chromatography–mass spectrometry

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    Many lysosomal storage diseases are characterized by an increased urinary excretion of glycoconjugates and oligosaccharides that are characteristic for the underlying enzymatic defect. Here, we have used capillary high-performance anion-exchange chromatography (HPAEC) hyphenated to mass spectrometry to analyze free oligosaccharides from urine samples of patients suffering from the lysosomal storage disorders fucosidosis, α-mannosidosis, GM1-gangliosidosis, GM2-gangliosidosis, and sialidosis. Glycan fingerprints were registered, and the patterns of accumulated oligosaccharides were found to reflect the specific blockages of the catabolic pathway. Our analytical approach allowed structural analysis of the excreted oligosaccharides and revealed several previously unpublished oligosaccharides. In conclusion, using online coupling of HPAEC with mass spectrometric detection, our study provides characteristic urinary oligosaccharide fingerprints with diagnostic potential for lysosomal storage disorders

    Savanna burning methodology for fire management and emissions reduction: a critical review of influencing factors

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    Savanna fire is a major source of global greenhouse gas (GHG) emissions. In Australia, savanna fire contributes about 3% of annual GHG emissions reportable to the Kyoto Protocol. In order to reduce GHG emissions from savanna burning, the Australian government has developed and approved a Kyoto compliant savanna controlled burning methodology—the first legal instrument of this kind at a global level—under its Emission Reduction Fund. However, this approved methodology is currently only applicable to nine vegetation fuel types across northern parts of Australia in areas which receive on average over 600 mm rainfall annually, covering only 15.4% of the total land area in Australia.Savanna ecosystems extend across a large proportion of mainland Australia. This paper provides a critical review often key factors that need to be considered in developing a savanna burning methodology applicable to the other parts of Australia. It will also inform discussion in other countries intent on developing similar emissions reduction strategies

    The History, Relevance, and Applications of the Periodic System in Geochemistry

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    Geochemistry is a discipline in the earth sciences concerned with understanding the chemistry of the Earth and what that chemistry tells us about the processes that control the formation and evolution of Earth materials and the planet itself. The periodic table and the periodic system, as developed by Mendeleev and others in the nineteenth century, are as important in geochemistry as in other areas of chemistry. In fact, systemisation of the myriad of observations that geochemists make is perhaps even more important in this branch of chemistry, given the huge variability in the nature of Earth materials – from the Fe-rich core, through the silicate-dominated mantle and crust, to the volatile-rich ocean and atmosphere. This systemisation started in the eighteenth century, when geochemistry did not yet exist as a separate pursuit in itself. Mineralogy, one of the disciplines that eventually became geochemistry, was central to the discovery of the elements, and nineteenth-century mineralogists played a key role in this endeavour. Early “geochemists” continued this systemisation effort into the twentieth century, particularly highlighted in the career of V.M. Goldschmidt. The focus of the modern discipline of geochemistry has moved well beyond classification, in order to invert the information held in the properties of elements across the periodic table and their distribution across Earth and planetary materials, to learn about the physicochemical processes that shaped the Earth and other planets, on all scales. We illustrate this approach with key examples, those rooted in the patterns inherent in the periodic law as well as those that exploit concepts that only became familiar after Mendeleev, such as stable and radiogenic isotopes

    Measurement of prompt J/ψ pair production in pp collisions at √s = 7 Tev

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    Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV

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    Study of hadronic event-shape variables in multijet final states in pp collisions at √s=7 TeV

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