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This article presents an analysis of the prospective costs of RCRA corrective action for private, nonfederal facilities. Two data bases developed by Research Triangle Institute and a remedial action cost model developed by CH2M Hill provide the foundation for this work. The methodology has two components, a remedial action knowledge base and a discrete-state Monte Carlo analysis. Under base case assumptions, it is estimated that the total costs of RCRA corrective action will be $240 billion, with a 5 percent chance the costs will be less than $170 billion and a 5 percent chance the costs will be more than $377 billion.  相似文献   
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Several protein kinases have been shown to be involved in the regulation of cell growth and differentiation. Molecules, regulating the activity of these protein kinases, also effect the activity of certain transport systems. Genetic experiments, suggesting a similar connection between the regulation of cell growth and transport functions in MDCK cells, are discussed.  相似文献   
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Measurement of environmental endotoxin exposures is complicated by variability encountered using current biological assay methods arising in part from lot-to-lot variability of the Limulus-amebocyte lysate (LAL) reagents. Therefore, we investigated the lot-to-lot repeatability of commercially available recombinant Factor C (rFC) kits as an alternative to LAL. Specifically, we compared endotoxin estimates obtained from rFC assay of twenty indoor dust samples, using four different extraction and assay media, to endotoxin estimates previously obtained by Limulus amebocyte lysate (LAL) assay and amounts of 3-hydroxy fatty acids (3-OHFA) in lipopolysaccharide (LPS) using gas-chromatography mass spectroscopy (GC-MS). We found that lot-to-lot variability of the rFC assay kits does not significantly alter endotoxin estimates in house dust samples when performed using three of the four assay media tested and that choice of assay media significantly altered endotoxin estimates obtained by rFC assay of house dust samples. Our findings demonstrate lot-to-lot reproducibility of rFC assay of environmental samples and suggest that use of rFC assay performed with Tris buffer or water as the extraction and assay medium for measurement of endotoxin in dust samples may be a suitable choice for developing a standardized methodology.  相似文献   
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Comparative gas cleaning performance of a pilot-scale venturi scrubber with throat dimensions of 6 in. wide × 1 2 in. long × 1 2 in. deep was obtained for the following three methods of water injection: a system of spray nozzles located along each short side of the throat (Figure 2a); a continuous slot located immediately above the nozzles, along each short side of the throat (Figure 2b); and a weir located 2 ft above the spray nozzles along long side of the throat (Figure 2c). For each method of water injection the gas cleaning performance, as a function of the pressure drop, was measured by two tests: absorption of SO2 and collection efficiency for particles of methylene blue of controlled size.  相似文献   
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Conditions for successful common-pool resources management institutions have been systematized by Elinor Ostrom as a set of “design principles for robust governance”. The comparison of two attempts to developing a local informal managing institution for shrimp trawling, 30 years apart (the late 1970s and 2010 attempts), and in the same community (therefore, the same socioecological system—SES) in Southern Brazil, provides a convenient ground to test the hypothesis that the degree of success of each attempt is related to the degree of adherence to Ostrom’s principles. Moreover, the comparison allows investigating how conditions and changes in the SES affect management institutions. Our institutional analysis showed that the 1970s attempt followed a local rule that best fitted almost all principles, which may explain its relative success and longer-lasting activity. However, changes such as the emergence of new technologies and increased fishing activity gradually led to an erosion of the local rule. A low level of group cohesion, regional socioeconomic changes, increased fishing effort, and lack of legal provisions for fishers to develop local managing institutions were the main factors that led to institutional failure in the two evaluated attempts. Additionally, the lack of ability to adapt to changing conditions weakened the continuity of the management regime. Although Brazil has created new fishery co-management policies, strategies to enable institutions at local levels are urgently needed for improved performance.  相似文献   
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A Milton  M Johnson 《Chemosphere》1999,39(5):765-779
The environmental distribution, transfer and ecotoxicological risk associated with arsenic in a grassland ecosystem established on metalliferous mine tailings has been determined. High levels of arsenic in the mine tailings (630 +/- 34 mg kg-1) were not reflected in live vegetation due to the physico-chemical nature of the tailings which mitigate against plant uptake. However, elevated levels of arsenic were associated with plant litter. Low concentrations of arsenic in herbivorous invertebrates mirrored those found in their food, although there was evidence of minor detrivoral food chain transfer. Dietary exposure of small mammals to arsenic was well below that demonstrated to induce a toxicological response, and tissue concentrations were consistently below analytical detection limits. There appears to be little ecotoxicological risk associated with arsenic residues at the mine site investigated.  相似文献   
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