This paper examines changes in the provision of water services, and in particular drinking water supply, in two Member States of the European Union, Britain England and Wales and France, by considering the impact of the twin processes of water service privatization and the Europeanization of environmental regulatory regimes. The paper demonstrates that in two nations with very different water service traditions, the articulation of these processes has led to profound shifts not only in management style but also in the perception of drinking water supply as a service to consumers. The British and French models are compared as are their responses to these twin processes. It is argued that while the British model has proved more responsive to the exigencies of European Union environmentalstandards,this has been at the expense of public confidence. In France, the existence of a well established traditional management style is, potentially, under greater long term threat from the growth of private water companies and the increasing importance of European legislation. 相似文献
When the cold war ended, the United States stopped developing,testing and building nuclear weapons at nearly all of its former nuclear weapon sites. The Department of Energy (DoE) began a massive environmental remediation programme, which includes engaging surrounding communities in a future land use planning process. Using the Savannah River site as an example, we show that this process faces large obstacles, especially a legacy of mistrust of the DoE and organizational limitations at the federal and local government scales. These hinder open dialogue about future land use. The authors suggest three planning principles for future land use planning and organizational issues that must be addressed before these can be fruitfully explored. 相似文献
Territorial disputes in the South China Sea have been exacerbated by the great potential for oil reserves in the area. The Spratly Islands have been a major object of these disputes. While China and other countries have softened their positions to a degree, questions remain regarding how each country would cooperate in oil exploration in this area. The ultimate resolution of the dispute over the Spratly Islands could set an example for the future handling of rival claims, but whether the approach will be one of cooperation or conflict is unclear. 相似文献
The relationship between stability and change in social-ecological systems has received considerable attention in recent years, including the expectation that significant environmental changes will drive observable consequences for individuals, communities, and populations. Migration, as one example of response to adverse economic or environmental changes, has been observed in many places, including parts of the Far North. In Arctic Alaska, a relative lack of demographic or migratory response to rapid environmental and other changes has been observed. To understand why Arctic Alaska appears different, we draw on the literature on environmentally driven migration, focusing on three mechanisms that could account for the lack of response: attachment, the desire to remain in place, or the inability to relocate successfully; alternatives, ways to achieve similar outcomes through different means; and buffering, the reliance on subsidies or use of reserves to delay impacts. Each explanation has different implications for research and policy, indicating a need to further explore the relative contribution that each makes to a given situation in order to develop more effective responses locally and regionally. Given that the Arctic is on the front lines of climate change, these explanations are likely relevant to the ways changes play out in other parts of the world. Our review also underscores the importance of further attention to the details of social dynamics in climate change impacts and responses.
An account is given about the development of the gametes of the holopelagic coronate scyphomedusa Periphylla periphylla (Péron and Lesueur 1809). The gonads of the species are complex and differ from those thus far described in Scyphozoa in
having this characteristic composition of trophocytes, follicle cells, gamete-releasing pores, mucus cells, and resorption
cells. Our results differ from those of previous coronate studies with respect to the contact of the oocytes with the gonad
tissue throughout the duration of development. Among the Medusozoa, follicle cells have thus far been considered as an apomorphy
for the Staurozoa, but their presence in the Scyphozoa casts some doubts on this assumption. From morphological structure
and examination of the gonads and gametes, it can be deduced that P. periphylla has true organs and that gamete release is continuous. These results supplement our knowledge of the reproductive biology
of this mesopelagic species. 相似文献
Kelp forests are enormously productive, and they and adjacent habitats support large populations of suspension feeders. What do these suspension feeders eat? Intuitively, we might expect that kelp primary production is a key form of trophic support for these animals. Indeed, a large and growing number of studies using carbon stable isotope data, typically collected over short time periods, have asserted that detritus from kelps is an important, and in some cases the main, food source for coastal benthic suspension feeders. This view has been incorporated into several textbooks and review papers covering kelp forest ecosystems, and loss of trophic support for benthic suspension feeders is now often invoked as an ecosystem consequence of top-down or other impacts on kelp forests. More direct evidence, however, suggests that these animals mainly eat phytoplankton and, in some cases, bacteria or zooplankton. Because isotope values of pure coastal phytoplankton, uncontaminated with detritus, are difficult to obtain, present studies have largely relied on single measurements from offshore environments or from the literature, which typically reflects offshore values. We review the evidence showing that phytoplankton isotope values can, and are expected to, vary widely in coastal waters and that inshore phytoplankton may often be enriched in 13C compared to offshore phytoplankton. This unaccounted-for variation may have systematically biased the results of such trophic studies toward finding large contributions of kelp detritus to suspension-feeder diets. We review some key stable isotope studies and put forth evidence for alternative explanations of the isotope patterns presented. Finally, we make recommendations for future isotope studies and describe several approaches for progress in this area. New techniques, particularly flow cytometry and compound-specific stable isotope analysis, provide ways to shed light on this interesting and important ecological issue. 相似文献
Summary The biology and behavior of Xylocopa virginica L. were followed in the area of Athens, Georgia (USA) from August 1973 until September 1974. Several nests were X-rayed regularly during the developmental period of the bees, and information about the life cycle and development was obtained. The bees emerge in June and stay in their nests with their sibs throughout the summer, fall, and winter, leaving only occasionally on warm days to search for nectar as food. In March and April males defend nest-side territories and mate with most females. The males die in the late spring and the females dig nests, provision them, and rear up to 8 or 9 bees in each nest. Many females live 2 years, and often 2 to 3 females are present in each nest, but only 1 works and lays eggs. Emergence of adults from pupae is nearly synchronized, irrespective of age. 相似文献