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131.
132.
The U.N. Framework Convention on Climate Change (FCCC) allows for the joint implementation (JI) of measures to mitigate the emissions of greenhouse gases. The concept of JI refers to the implementation of such measures in one country with partial or full financial and/or technical support from another country, potentially fulfilling some of the supporting country's emission-reduction commitment under the FCCC. At present, all JI transactions are voluntary, and no country has claimed JI credit against existing FCCC commitments. Nevertheless, JI could have important implications for both the economic efficiency and the international equity of the implementation of the FCCC. This paper discusses some of the information needs of JI projects and seeks to clarify some of the common assumptions and arguments about JI. Issues regarding JI are distinguished according to those that are specific to JI and those that apply to JI as well as other types of regimes and transactions. The focus is on the position of developing countries and their potential risks and benefits regarding JI. 相似文献
133.
Relationships among Isolated Wetland Size, Hydroperiod, and Amphibian Species Richness: Implications for Wetland Regulations 总被引:6,自引:0,他引:6
Joel W. Snodgrass †‡ Mark J. Komoroski † A. Lawrence Bryan JR. † Joanna Burger 《Conservation biology》2000,14(2):414-419
Abstract: Wetland development within the United States is regulated primarily by size. Decisions concerning wetland destruction or conservation are therefore based in part on three inherent assumptions: (1) small wetlands contain water for short portions of the year; (2) small wetlands support few species; and (3) species found in small wetlands are also found in larger wetlands. We tested these assumptions using data on wetland size, relative hydroperiod (drying scores), and relative species richness of amphibians in depression wetlands of the southeastern United States. We found a significant (p = 0.03) but weak (r2 = 0.05) relationship between hydroperiod and wetland size and no relationship (p = 0.48) between amphibian species richness and wetland size. Furthermore, synthetic models of lentic communities predict that short-hydroperiod wetlands support a unique group of species. Empirical investigations support this prediction. Our results indicate that hydroperiod length should be included as a primary criterion in wetland regulations. We advocate a landscape approach to wetlands regulation, focused in part on conserving a diversity of wetlands that represent the entire hydroperiod gradient. 相似文献
134.
We surveyed patterns in the relative abundance and size structure of the sea stars Pisaster ochraceus and Evasterias troschelii in five habitat types of varying structural complexity and prey availability (sand/cobble, boulder, and rocky intertidal; pilings; and floating docks) in Puget Sound and the San Juan Islands, Washington. For both species, small sea stars were most abundant in the most structurally complex habitat type (boulder), where they occurred almost exclusively under boulders during low tide. Larger individuals became more abundant as structural complexity decreased, occurring more frequently in open habitat types (rocky shores, pilings, and docks) known to have greater abundances of prey resources. Gull foraging observations and experiments demonstrated that exposed small sea stars of both species were highly vulnerable to predation, suggesting that small sea stars require structural complexity (crevice microhabitat) as a predation refuge. Large sea stars, once attaining a size refuge from predation, appear to migrate to more exposed habitat types with more abundant food resources. These results suggest parallel ontogenetic habitat shifts in two co-occurring consumer species related to a shared predation risk at early life stages and demonstrate how the relative importance of top-down and bottom-up processes may differ with ontogeny. 相似文献
135.
ML Alosco MB Spitznagel KH Fischer LA Miller V Pillai J Hughes J Gunstad 《Traffic injury prevention》2012,13(5):468-475
Objective: Distracted driving is a known contributor to traffic accidents, and many states have banned texting while driving. However, little is known about the potential accident risk of other common activities while driving, such as eating. The objective of the current study was to examine the adverse impact of eating/drinking behavior relative to texting and nondistracted behaviors on a simulated driving task. Methods: A total of 186 participants were recruited from undergraduate psychology courses over 2 semesters at Kent State University. We utilized the Kent Multidimensional Assessment Driving Simulation (K-MADS) to compare simulated driving performance among participants randomly assigned to texting (N = 45), eating (N = 45), and control (N = 96) conditions. Multivariate analyses of variance (MANOVA) were conducted to examine between-group differences on simulated driving indices. Results: MANOVA analyses indicated that groups differed in simulated driving performance, F(14, 366) = 7.70, P < .001. Both texting and eating produced impaired driving performance relative to controls, though these behaviors had approximately equal effect. Specifically, both texting and eating groups had more collisions, pedestrian strikes, and center line crossings than controls. In addition, the texting group had more road edge excursions than either eating or control participants and the eating group missed more stop signs than controls. Conclusions: These findings suggest that both texting and eating are associated with poorer simulated driving performance. Future work is needed to determine whether these findings generalize to real-world driving and the development of strategies to reduce distracted driving. 相似文献
136.
137.
Constructed wetlands are widely used for wastewater treatment, but there is little information on processes affecting their performance in cold climates, effects of plants on seasonal performance, or plant selection for cold regions. We evaluated the effects of three plant species on seasonal removal of dissolved organic matter (OM) (measured by chemical oxygen demand and dissolved organic carbon) and root zone oxidation status (measured by redox potential [Eh] and sulfate [SO4(2-)]) in subsurface-flow wetland (SSW) microcosms. A series of 20-d incubations of simulated wastewater was conducted during a 28-mo greenhouse study at temperatures from 4 to 24 degrees C. Presence and species of plants strongly affected seasonal differences in OM removal and root zone oxidation. All plants enhanced OM removal compared with unplanted controls, but plant effects and differences among species were much greater at 4 degrees C, during dormancy, than at 24 degrees C, during the growing season. Low temperatures were associated with decreased OM removal in unplanted controls and broadleaf cattail (Typha latifolia L.) microcosms and with increased removal in beaked sedge (Carex rostrata Stokes) and hardstem bulrush [Schoenoplectus acutus (Muhl. ex Bigelow) A. & D. L?ve var. acutus] microcosms. Differences in OM removal corresponded to species' apparent abilities to increase root zone oxygen supply. Sedge and bulrush significantly raised Eh values and SO4(2-) concentrations, particularly at 4 degrees C. These results add to evidence that SSWs can be effective in cold climates and suggest that plant species selection may be especially important to optimizing SSW performance in cold climates. 相似文献
138.
Kost DA Bigham JM Stehouwer RC Beeghly JH Fowler R Traina SJ Wolfe WE Dick WA 《Journal of environmental quality》2005,34(2):676-686
Beneficial and environmentally safe recycling of flue gas desulfurization (FGD) products requires detailed knowledge of their chemical and physical properties. We analyzed 59 dry FGD samples collected from 13 locations representing four major FGD scrubbing technologies. The chemistry of all samples was dominated by Ca, S, Al, Fe, and Si and strong preferential partitioning into the acid insoluble residue (i.e., coal ash residue) was observed for Al, Ba, Be, Cr, Fe, Li, K, Pb, Si, and V. Sulfur, Ca, and Mg occurred primarily in water- or acid-soluble forms associated with the sorbents or scrubber reaction products. Deionized water leachates (American Society for Testing and Materials [ASTM] method) and dilute acetic acid leachates (toxicity characteristic leaching procedure [TCLP] method) had mean pH values of >11.2 and high mean concentrations of S primarily as SO(2-)4 and Ca. Concentrations of Ag, As, Ba, Cd, Cr, Hg, Pb, and Se (except for ASTM Se in two samples) were below drinking water standards in both ASTM and TCLP leachates. Total toxicity equivalents (TEQ) of dioxins, for two FGD products used for mine reclamation, were 0.48 and 0.53 ng kg(-1). This was similar to the background level of the mine spoil (0.57 ng kg(-1)). The FGD materials were mostly uniform in particle size. Specific surface area (m2 g(-1)) was related to particle size and varied from 1.3 for bed ash to 9.5 for spray dryer material. Many of the chemical and physical properties of these FGD samples were associated with the quality of the coal rather than the combustion and SO2 scrubbing processes used. 相似文献
139.
F Jay Breidt Duane C. Roes Joel I. Wagner Mark D. Flora 《Journal of the American Water Resources Association》1991,27(4):593-602
ABSTRACT: Existing water quality for the Middle Delaware Scenic and Recreational River is significantly better than is required by current standards, leaving a potential for degradation. A method is presented for deriving candidate antidegradation water quality criteria for this segment of the Delaware River using statistical analysis of historic (ambient) water quality data. Data for 34 water quality parameters are first evaluated for data density, serial correlation, trend, seasonality, and other factors. These preliminary analyses are based on observation of data plots and application of distribution-free statistical techniques that are insensitive to outliers and are robust to relatively mild violations of basic assumptions. Data for 12 of the parameters have sufficient density for further analysis and can reasonably be modeled as independent and identically distributed over time (either seasonally or for the entire data sets). For these 12 parameters, distribution-free statistical methods are developed and used to derive intervals within which there is high confidence (usually greater than 95 percent) that the quantiles with potential use as anti-degradation criteria (the 0.85th, 0.90th, and 0.95th quantiles in this study) for a particular parameter lie. 相似文献
140.
Joel S. Hirschhorn 《补救:环境净化治理成本、技术与工艺杂志》1999,9(4):87-107
Mad cow disease and related transmissible spongiform encephalopathy diseases (TSEs) in both animals and humans have received worldwide attention. Interestingly, the issue of managing biohazardous wastes, for which TSE agents are an issue, has received little attention by environmental professionals. The burial of wastes associated with mad cow and related diseases may eventually lead to unusual challenges for remediation professionals. The core challenge is that medical researchers have confirmed the incredible difficulty in destroying TSE infectious agents or pathogens, generally called prions. Risk reduction is certainly possible with treatment technologies, but complete elimination of risk by reliable and verifiable destruction of all TSE agents is probably infeasible. Proving the efficacy of any waste treatment method for TSE-infected wastes is not practical because there is no commercially available test for TSE pathogens (although one is expected soon) and in only a few cases is there a reasonable surrogate approach. These circumstances have contributed to some biohazardous waste managers discounting the TSE issue. The goal of this article is to more thoroughly analyze available information and various risks to identify useful implications for alternative waste management technologies. A number of prudent actions can be taken in recognition of the TSE problem, including more careful assessment of treatment technologies, avoiding any reuse or recycling of waste treatment residues, using air pollution control systems to avoid releases of materials possibly containing infectious agents, and using wastewater pretreatment prior to sewer disposal. 相似文献