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431.
This study was conducted to identify factors that influence individuals' acceptance of environmental management technologies for cleaning up hazardous materials. The study sample consisted of approximately 2600 residents living within emergency response zones surrounding eight US Army's Chemical Weapons Stockpile sites. The findings suggest that residents perceive clear differences between the desirable characteristics of the two technologies: incineration and neutralization. In a relative comparison, the majority of positive technological attributes were associated with incineration. Positive perceptions toward incineration were associated with individuals who trust the Army, who perceive that the media have made them more trusting of weapons disposal activities, who are ready to participate, and who are male. Unlike incineration, there was insufficient evidence that individual factors influence variations in perceptions toward neutralization. No community factor was related to perceptions toward either incineration or neutralization.  相似文献   
432.
433.
We examine the irreplaceability of sites in the context of the species set covering problem and the maximal covering species problem. We show that a succession of 0-1 programming problems can be solved to quickly determine the set of irreplaceable sites. For the widely available Oregon data set, we find a general lack of trend in the number of irreplaceable sites with the number of sites available for selection used. Moreover, we observe that irreplaceability at one level of resource may not be a predictor of irreplaceability at a higher or a lower level of resource. Finally, we investigate the economic value of irreplaceable sites by trial removals of those sites. This paper is dedicated to the memory of Dr. Charles S. ReVelle.  相似文献   
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In the mid-1980s, the first formal seat-belt enforcement program in the United States was conducted in Elmira, NY. Front seat-belt use increased from 49% to 80%, and the Elmira program became a model for other such programs. In the spring of 1999, the New York State Police launched a statewide seat-belt enforcement campaign, and the Elmira program was revived as part of this effort. This 3-week program was coordinated by the Chemung County Sheriff's Office, and carried out in cooperation with local police departments as well as the state police. The earlier Elmira program emphasized the health and safety benefits of seat belts and warning periods prior to tickets being issued. The 1999 program featured a strong no-excuses, no-warning enforcement message, 32 belt-use checkpoints, and publicity about the enforcement through a variety of mechanisms, including feedback signs that informed motorists of current belt use rates. Front seat-belt use increased from 69% to 90%. Public opinion surveys indicated the program was well known to Elmira residents, and had the support of 79% of those polled. The 1999 Elmira program demonstrates that high-intensity enforcement programs can increase seat-belt use to very high levels with strong community support.  相似文献   
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Laboratory experiments tested whether the cardiac activity of two species of limpets (Cellana spp.), co-occurring on the rocky shores of Hong Kong but having different zonal distributions, was differently affected by variations in physical environmental characteristics. Experiments reproduced exposure of limpets to dehydration, high water temperature and reduced salinity, all conditions that can occasionally be faced by animals during low tides. Cardiographic traces were obtained using a non-invasive method based on infrared light sensors glued onto the limpet shell in a position directly over the heart. The signals were filtered and amplified, viewed on portable oscilloscopes and automatically transferred to computer. When tested under acclimation temperatures, the lower shore C. toreuma had faster heart rates than the upper shore C. grata, both in air and when submerged in seawater. Regular alternation of heartbeating and acardia were observed in C. grata exposed to both dry and saturated air, whilst C. toreuma showed transient acardia only during exposure to dry air. Both species showed a similar increase in heart rate with increasing temperature (Q10~1.8 in the range 25-34°C). When submerged in freshwater, C. grata regularly alternated acardia with beating at a rate slightly lower than in seawater, whilst C. toreuma showed strong bradycardia with reduction of beat amplitude, followed by steady acardia. Recovery of heartbeating after return to initial salinity was faster in C. grata, whilst C. toreuma, initially bradycardic, showed a consistent return to tachycardia. Overall, this study shows that the two congeneric species exhibit different cardiac responses to variations in environmental characteristics, which may be related to their differing vertical distribution.  相似文献   
438.
This article is intended to provide an overview of the issues involved in remediation contracting, from general principles of contract law and negotiation, to specific contract provisions of interest to the remediation community, to the practical consequences of including or not including these provisions on disputes arising under the contract. This article does not treat every potential issue arising in contracts concerning remediation, but hopefully it discusses many of these issues and provides an overview that will be helpful to the reader.  相似文献   
439.
Gene flow among 18 widely separated populations of the starfishLinckia laevigata was investigated using allozyme electrophoresis at seven polymorphic enzyme loci. Little genetic differentiation was observed among East Indian-West Pacific populations separated by thousands of kilometres. Gene flow was estimated to be of the same order of magnitude as that found in the highly connected Great Barrier Reef region. The absence of genetic structure over such a broad geographic range is consistent with any of three conclusions: (1) there is extensive dispersal among widely separated populations across the range examined, (2) there has been a rapid expansion of the East Indian-West Pacific populations in the recent past, or (3) the loci surveyed are under the influence of balancing selection. The first two conclusions are not totally exclusive, since a recent expansion over several thousand generations would also require rapid dispersal at some stage, although present-day levels of dispersal need not be of the same order. With the available data, it is not possible to distinguish which of these mechanisms is the most likely. The most parsimonious conclusion is that extremely low levels of population differentiation are consistent with the existence of a large, homogeneous, panmictic population, with extensive dispersal occurring throughout the East Indian-West Pacific.  相似文献   
440.
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