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971.
Marc O. Ribaudo Jessica Gottlieb 《Journal of the American Water Resources Association》2011,47(1):5-14
Ribaudo, Marc O. and Jessica Gottlieb, 2011. Point‐Nonpoint Trading – Can It Work? Journal of the American Water Resources Association (JAWRA) 47(1):5‐14. DOI: 10.1111/j.1752‐1688.2010.00454.x Abstract: Water quality trading between point and nonpoint sources is of great interest as an alternative to strict command and control regulations on point sources for achieving water quality goals. The expectation is that trading will reduce the costs of water quality protection, and may speed compliance. The United States Environmental Protection Agency has issued guidance to the States on developing point‐nonpoint trading programs, and United States Department of Agriculture is encouraging farmer participation. However, existing point‐nonpoint trading programs have resulted in very few trades. Supply side and demand side impediments seem to be preventing trades from occurring in most trading programs. These include uncertainty over the number of discharge allowances different management practices can produce, high transactions costs of identifying trading partners, baseline requirements that eliminate low‐cost credits, the reluctance of point sources to trade with unfamiliar agents, and the perception of some farmers that entering contracts with regulated point sources leads to greater scrutiny and potential future regulation. Many of these problems can be addressed through research and program design. 相似文献
972.
Annekatrin Wagner Stephan Hülsmann Lothar Paul Rüdiger J. Paul Thomas Petzoldt René Sachse Thomas Schiller Bettina Zeis Jürgen Benndorf Thomas U. Berendonk 《Marine Biology》2012,159(11):2543-2559
To predict the coherence in local responses to large-scale climatic forcing among aquatic systems, we developed a generalized approach to compare long-term data of dimictic water bodies based on phenomenologically defined hydrographic events. These climate-sensitive phases (inverse stratification, spring overturn, early thermal stratification, summer stagnation) were classified in a dual code (cold/warm) based on threshold temperatures. Accounting for a latitudinal gradient in seasonal timing of phases derived from gradients in cumulative irradiation (2.2?days per degree latitude), we found a high spatial and temporal coherence in warm–cold patterns for six lakes (84?%) and the Baltic Sea (78?%), even when using the same thresholds for all sites. Similarity to CW-codes for the North Sea still was up to 72?%. The approach allows prediction of phase-specific warming trends and resulting instantaneous or time-delayed ecological responses. Exemplarily, we show that warming during early thermal stratification controls food-web-mediated effects on key species during summer. 相似文献
973.
974.
975.
Protected areas (PAs) are key elements for biodiversity conservation and ecosystem services. Brazil has the largest PA system in the world, covering approximately 220 million ha. This system expanded rapidly in the mid‐1990s to the mid‐2000s. Recent events in Brazil, however, have led to an increase in PA downgrading, downsizing, and degazettement (PADDD). Does this reflect a shift in the country's PA policy? We analyzed the occurrence, frequency, magnitude, type, spatial distribution, and causes of changes in PA boundaries and categories in Brazil. We identified 93 PADDD events from 1981 to 2012. Such events increased in frequency since 2008 and were ascribed primarily to generation and transmission of electricity in Amazonia. In Brazilian parks and reserves, 7.3 million ha were affected by PADDD events, and of these, 5.2 million ha were affected by downsizing or degazetting. Moreover, projects being considered by the Federal Congress may degazette 2.1 million ha of PA in Amazonia alone. Relaxing the protection status of existing PAs is proving to be politically easy in Brazil, and the recent increase in frequency and extension of PADDD reflects a change in governmental policy. By taking advantage of chronic deficiencies in financial and personnel resources and surveillance, disputes over land tenure, and the slowness of the Brazilian justice, government agencies have been implementing PADDD without consultation of civil society. If parks and reserves are to maintain their integrity, there will need to be investments in Brazilian PAs and a better understanding of the benefits PAs provide. Degradación, Reajuste, Eliminacióm de las Listas y Reclasificación de Áreas Protegidas en Brasil 相似文献
976.
Heide Spiegel Manfred Sager Michael Oberforster Klemens Mechtler Hans Peter Stüger Andreas Baumgarten 《Environmental geochemistry and health》2009,31(5):549-560
Eighteen representative sites for the Austrian grain-growing and eight for the potato-growing zones (soils and crops) were
investigated. On each site, total element contents (B, Ba, Ca, Cd, Co, Cu, Fe, K, Li, Mg, Mn, Mo, Na, P, Sr and Zn) were determined
in 4–12 varieties of winter wheat (n = 136), 6 varieties of spring durum wheat (n = 30), 5 varieties of winter durum wheat (n = 15), 7 varieties of rye (n = 49), 5 varieties of spring barley (n = 30) and 5 varieties of potatoes (n = 40). Element accumulations in grain species and potato tubers varied significantly with site conditions, with the main
exceptions for B in potatoes and wheat as well as for Zn, Cu and Co in durum wheat. On average, across all investigated sites,
differences in varieties occurred concerning the elements Ca, Cd, Ba, Sr and Zn (except Zn in potatoes and winter durum).
A rough estimation revealed that an average Austrian consumer of wheat, rye and potatoes meets more than 50% of the needs
of daily element intake for K, P and Mg, between 36 and 72% for Fe, Zn and Cu, and more than 100% for Co, Mo and Mn. In particular,
the elements Ca and Na have to be added from other sources. 相似文献
977.
Kamal A. Rashid Masood Arjmand Heinrlch Sandertnann Ralph O. Mumma 《Journal of environmental science and health. Part. B》2013,48(6):721-729
Abstract Chloroanilines are constituents of many agrochemicals and have been found to be metabolized to succinic acid conjugates, e.g., succinamides and succinimides. The mutagenic potential of five chloroanilines and their succinamides and succinimide derivatives have been tested with two strains of Salmonella typhimurium (TA98 and TA100) with and without rat hepatic micro‐somal fraction. None of the compounds produced a dose response effect with a two‐fold increase in revertants indicating that these compounds are not mutagens or promutagens in these assays. 相似文献
978.
Ali Jamshidparvar Faramin Javandel Alireza Seidavi Francisco Peña Blanco Andrés L. Martínez Marín Carmen Avilés Ramírez Estrella Agüera Buendía Nieves Núñez-Sánchez 《Environmental science and pollution research international》2017,24(30):23571-23577
Increasing levels of Heracleum persicum (golpar) in drinking water were studied in broilers. Two hundred and forty-one-day-old male chickens were allocated to one of six treatments: control, without added phytogenics nor probiotics in drinking water, and probiotics at recommended manufacturer’s level (P) or 1.0, 1.5, 2.0, and 2.5 ml/l of golpar extract solution (G1, G1.5, G2, and G2.5 treatments, respectively) in drinking water. As a result of this study, no linear or quadratic trends in the feed intake (FI) and feed conversion rate (FCR) due to golpar supplementation were found. Body weight gain, final body weight, and relative carcass weight showed a positive linear response with increasing levels of golpar supplementation. Neither golpar nor probiotics had effects on the percentages of edible parts of the carcass. Golpar supplementation levels caused a linear negative response of the albumin content in blood plasma, whereas both abdominal fat as percentage of carcass weight and uric acid levels in blood plasma linearly increased. The effects on Ig responses were only observed at 42 days of age and were similar in probiotics and the highest level of golpar supplementation. Based on our results, both probiotics and golpar supplementation could improve broiler performance and immune function. 相似文献
979.
C. Henry Obasi U. Martin Obidiegwu N. Godwin Onyeagoro O. Innocent Arukalam C. Genevive Onuegbu N. Francis Onuoha M. Chinomso Ewulonu 《Journal of Polymers and the Environment》2017,25(3):544-555
We report in this paper the transport of an aromatic solvent, xylene through palm pressed fibre filled low density polyethylene composites studied at three different temperatures (40, 60, and 80 °C) by conventional weight-gain method. The diffusion parameters were investigated with special reference to the effect of fibre content, temperature and particle size. The effect of alkali treatment on solvent uptake was also analyzed. The transport coefficients of diffusion, permeation and sorption were determined to evaluate the influence of interface bonding on transport properties. The van’t Hoff relationship was used to determine the thermodynamic parameters and was found that the estimated free energies of sorption were all positive, indicating non-spontaneity of the solubility of PPF/LDPE composites. The first order kinetic rate constant and swelling parameters were also evaluated. 相似文献
980.
Levels of lead, zinc, cadmium, copper and nickel were determined in roadside moss samples within towns in the northern and south-eastern regions of Nigeria. Average lead level in the south-east (59 ppm) was higher than the average for the northern region (44 ppm). Average levels of zinc, cadmium, copper and nickel did not differ significantly between the two regions, with overall averages for the entire study area being 50.9, 1.2, 11.3 and 5.6 ppm for these metals. Lead levels were poorly correlated with those of the other metals, indicating that automobile emissions may not be the main source for these metals in the moss. In comparison with a previous study of the south-west region, the results indicate a generally slightly higher level of metal pollution in the south-west region than in both the northern and south-eastern regions. 相似文献