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Nicolas Perdrial Nicole Liewig Jean-Emmanuel Delphin Franoise Elsass 《Chemical Geology》2008,253(3-4):196-204
We monitored near-surface atmospheric fallout (15-cm above ground) and soil solution (at 15, 35 and 55 cm below ground) derived nanoparticles over an 8-month period by collecting the particles directly onto TEM grids in anthropogenically-influenced (vineyard) and pristine (native forest) sites in France. Particle clusters trapped on the grid were selected randomly and individual particles were binned into eight different groups (euhedral clays, weathered clays, salts, oxi-hydroxides, bacteria, non-living organic matter, aggregates and undetermined). Bacteria represent 9–23% of the collected nanoparticle area (ave. 9.4% and 18% for two atmospheric collection sites and ave. 23% for soil infiltration samples). Bacteria were most often associated with non-living organic matter and comprised a variety of morpho-types. Interestingly, 45% of all the bacteria analyzed by transmission electron microscopy and electron dispersive spectroscopy (TEM-EDX) showed the presence of intracellular grains significantly enriched in lead and phosphorus. Intracellular sequestration of Pb into polyphosphate bodies has been observed in the laboratory, but this is the first observation of this phenomenon in a natural environment. Furthermore, this suggests that microbial-bound Pb may be an important transport mechanism in subsurface environments. 相似文献
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Rupsha Banerjee Josey Kamanda Cynthia Bantilan Naveen P. Singh 《Natural Hazards》2013,65(3):1443-1464
This paper examines the relationship between local institutions and adaptation to climate variability in four semi-arid villages in India. Based on a qualitative survey, it draws attention to the constraints that farming households face, the role of institutions, and the implications for their capacities to adapt. Using an institutional framework, the study examines the role of local institutions in facilitating community adaptation to perceived climate variability. It was found that at the institutional and community level farmers rely on government schemes that provide social safety nets and the private sector such as moneylenders as sources of adaptation options regarding access to credit. Serious constraints emerged, however, in terms of adaptation to what may be a more challenging future. These constraints were further explored by means of grounded theory. The lack of collective feeling and action has hindered bargaining for better market prices and the development of alternate livelihood options. The need for better financial inclusion and access to more formal systems of finance is necessary to increase the overall adaptive capacity of households. During crisis situations or climatic shocks, the absence of these systems means the sale of household assets and resources especially among small and landless groups of farmers. Overall, rural households perceive that public, civic, and private institutions play a significant role in shielding them against the adverse effects of climate variability. The perceived importance of different institutions is, however, different across different categories of farmers, women, and labourers. 相似文献
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GeoJournal - This study builds on the fundamentals of the new economic geography and the skill-biased technological change argument, to empirically investigate whether increasing income/earning... 相似文献
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