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201.
Scott E Atkinson T.H Tietenberg 《Journal of Environmental Economics and Management》1982,9(2):101-121
Previous work by Atkinson and Lewis (J. Environ. Econ. Manag.1, 237–250 (1974)) and Anderson et al. (“An Analysis of Alternative Policies for Attaining and Maintaining a Short-Term NO2 Standard,” MATHTECH, Inc., Princeton, N.J., 1979) has indicated the tremendous cost advantages to be achieved by moving from a policy based on emission standards to one based on marketable emission permits. As Tietenberg (Land Econ.56, 391–416 (1980)) points out, however, neither of the major permit designs treated in the literature are optimal from all points of view. This has triggered a search for alternative permit designs, which, while they may not minimize compliance costs, have sufficient other virtues as to make them attractive on other grounds. The purpose of this paper is to examine, within the context of an empirical mathematical programming model, the air quality, emission, and cost consequences of two classes of the permit designs which can be implemented in the absence of information on control costs. This case study involves particulate control in St. Louis. 相似文献
202.
In situ growth rates were determined, using two, 1-yr mark/recapture experiments, conducted between September 1991 and July 1993, for an undescribed mytilid, Seep Mytilid Ia, at three hydrocarbon seep sites in the Gulf of Mexico. The sites are located at depths of 540 to 730m, approximately 27°45N; 91°30W, and are separated by distances of 6 to 18 miles. These seep mytilids harbor methanotrophic endosymbionts and use methane as both a carbon and energy source. The mussel habitats were chemically characterized by analysis of water samples taken from precisely located microenvironments over, among and below the mussels, using small-volume, interstitial water samplers and the Johnson Sea Link submersible. Substantial differences were found in habital conditions, growth rates, and population structure for the mussels at the three sites examined. The growth rate of these seep mytilids reflects the methane concentration in their immediate habitat. Mussels at sites with abundant methane had growth rates that were comparable to shallow water mytilids at similar temperatures (5 to 8°C) with increases in shell length up to 17 mm yr–1 documented for smaller mussels (<40 mm shell length). In conjunction with measurements of growth rates, three condition indices (glycogen content, tissue water content, and the ratio of ash-free dry weight to shell volume) were used to determine the relationship between the condition of the mussels, their growth rates, and their habitat chemistry. The three condition indices were correlated with growth rate and were often significantly different between mussels in different samples. 相似文献
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Scott?A.?ShafferEmail author Yann?Tremblay Jill?A.?Awkerman R.?William?Henry Steven?L.?H.?Teo David?J.?Anderson Donald?A.?Croll Barbara?A.?Block Daniel?P.?Costa 《Marine Biology》2005,147(4):833-843
Light-based archival tags are increasingly being used on free-ranging marine vertebrates to study their movements using geolocation estimates. These methods use algorithms that incorporate threshold light techniques to determine longitude and latitude. More recently, researchers have begun using sea surface temperature (SST) to determine latitude in temperate regions. The accuracy and application of these algorithms have not been validated on free-ranging birds. Errors in both geolocation methods were quantified by double-tagging Laysan (Phoebastria immutabilis Rothschild) and black-footed (P. nigripes Audubon) albatrosses with both leg-mounted archival tags that measured SST and ambient light, and satellite transmitters. Laysan albatrosses were captured and released from breeding colonies on Tern Island, northwestern Hawaiian Islands (23°52N, 166°17W) and Guadalupe Island, Mexico (28°31N, 118°10W) and black-footed albatrosses from Tern Island. Studies were carried out between December 2002 and March 2003. For all birds combined, the mean ± SD great circle (GC) distance between light-based locations and satellite-derived locations was 400±298 km (n=131). Errors in geolocation positions were reduced to 202±171 km (n=154) when light-based longitude and SST-based latitude (i.e. SST/light) were used to establish locations. The SST/light method produced comparable results for two Laysan albatross populations that traveled within distinctly different oceanic regions (open ocean vs more coastal) whereas light-based methods produced greater errors in the coastal population. Archival tags deployed on black-footed albatrosses returned a significantly higher proportion of lower-quality locations, which was attributed to interference of the light sensor on the tag. Overall, the results demonstrate that combining measures of light-based longitude and SST-based latitude significantly reduces the error in location estimates for albatrosses and can provide valid latitude estimates during the equinoxes, when light-based latitude measurements are indeterminate.Communicated by J.P. Grassle, New Brunswick 相似文献
206.
Edward P. Glenn Christopher Lee Richard Felger Scott Zengel 《Conservation biology》1996,10(4):1175-1186
The lower delta of the Colorado River has been severely affected by the upstream diversion of water for human use. No river water is officially appropriated to support delta wetlands, yet large marsh areas of conservation interest still exist below the agricultural fields in Mexico. These are supported by flood water, agricultural drainage water, municipal sewage effluent, and seawater in the intertidal zone. From 1973 to 1993 the area of freshwater and brackish marsh varied widely, from 5800 to 63,000 ha. A new opportunity exists to restore wetlands in the delta now that the upstream water impoundments on the Colorado River are filled and flood flows are once again being directed to the delta. But flood control structures now channel most of the flood water directly to the sea, and most of the effluent waters are deposited in evaporation basins rather than used to support wetlands. If the Yuma Desalting Plant in the United States becomes operational and if the Rio Hardy wetlands continue to be drained, the area of brackish wetlands could decrease to less than 2000 ha in the near future. Preserving the remaining wetlands will require a binational water management plan. The plan should maximize the benefits to wetlands of flood and irrigation return flows that enter the delta, and it should minimize flood risks. 相似文献
207.
The regulation of pollen foraging by honey bees: how foragers assess the colony's need for pollen 总被引:2,自引:0,他引:2
Scott Camazine 《Behavioral ecology and sociobiology》1993,32(4):265-272
Summary The honey bee colony presents a challenging paradox. Like an organism, it functions as a coherent unit, carefully regulating its internal milieu. But the colony consists of thousands of loosely assembled individuals each functioning rather autonomously. How, then, does the colony acquire the necessary information to organize its work force? And how do individuals acquire information about specific colony needs, and thus know what tasks need be performed? I address these questions through experiments that analyze how honey bees acquire information about the colony's need for pollen and how they regulate its collection. The results demonstrate features of the colony's system for regulating pollen foraging: (1) Pollen foragers quickly acquire new information about the colony's need for pollen. (2) When colony pollen stores are supplemented, many pollen foragers respond by switching to nectar foraging or by remaining in the hive and ceasing to forage at all. (3) Pollen foragers do not need direct contact with pollen to sense the colony's change of state, nor do they use the odor of pollen as a cue to assess the colony's need for pollen. (4) Pollen foragers appear to obtain their information about colony pollen need indirectly from other bees in the hive. (5) The information takes the form of an inhibitory cue. The proposed mechanism for the regulation of pollen foraging involves a hierarchical system of information acquisition and a negative feedback loop. By taking advantage of the vast processing capacity of large numbers of individuals working in parallel, such a system of information acquisition and dissemination may be ideally suited to promote efficient regulation of labor within the colony. Although each individual relies on only limited, local information, the colony as a whole achieves a finely-tuned response to the changing conditions it experiences. 相似文献
208.
Jeffrey Conner Scott Camazine Daniel Aneshansley Thomas Eisner 《Behavioral ecology and sociobiology》1985,16(2):115-118
Summary The tenebrionid beetle Bolitotherus cornutus everts a pair of quinone-producing defensive glands in response to mammalian breath. Experiments with a controlled airstream indicate that the beetle recognizes breath on the basis of temperature, humidity, and airflow dynamics. Under attack by mice the beetle everts the glands immediately upon being mouthed and may secure its release as a result. Against ants the beetle is protected by its tough exoskeleton and usually refrains from everting the glands. Other arthropods also show defensive responses when breathed upon.Paper No. 77 of the series Defense Mechanisms of Arthropods 相似文献
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Laela S. Sayigh Peter L. Tyack Randall S. Wells Michael D. Scott A. Blair Irvine 《Behavioral ecology and sociobiology》1995,36(3):171-177
Signature whistles of 42 free-ranging bottle-nose dophin calves were compared to those of their mothers. Humans judged their similarity by inspection of spectrograms. There was a sex difference in the tendency of calves to produce whistles similar to or different from those of their mothers; most female calves produced whistles that were different from those of their mothers, whereas male calves were more likely to produce whistles that were similar to those of their mothers. Because matrilineally related females associate together and use signature whistles to establish and/or maintain contact with their calves, there may be a selective pressure for females to produce whistles that are distinct from those of their mothers. There may be fewer constraints governing whistle development in males, with the result that some males produce whistles similar to those of their mothers and others do not. 相似文献