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71.
Vestimentiferan tubeworms, which rely on intracellular sulfide-oxidizing autotrophic bacteria for organic carbon, flourish at deep-sea hydrothermal vents despite the erratic nature of their habitat. To assess the degree to which differences in habitat chemistry (sulfide, pH/CO2) might impact host and symbiont metabolic activity, Riftia pachyptila tubeworms were collected from habitats with low (H2S < 0.0001 mM) and high (up to 0.7 mM) sulfide concentrations. The elemental sulfur content of the symbiont-containing trophosome organ was lower in specimens collected from the low-sulfide site. Symbiont abundance, RubisCO activity, and trophosome carbon fixation rates were not significantly different for individuals collected from low- versus high-sulfide habitats. Carbonic anhydrase activities were higher in the anterior gas exchange organs of R. pachyptila from the low-sulfide habitat. Despite large differences in habitat chemistry, symbiont abundance and autotrophic potential were consistent, while the host appears to tailor carbonic anhydrase activity to environmental CO2 availability.  相似文献   
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Summary This paper considers the application of the principles of sustainable development to an airport situation. If sustainable development is to be enshrined as the global development pathway which reconciles economic and environmental issues then it must be applicable to a range of spatial scales. Airports will interact at a variety of levels with this multi-level decision making and enactment structure. The requirements imposed upon an airport may differ according to whether decisions are being taken by local, regional or national decision makers. Conflicts and uncertainties will inevitably result. Definitions of sustainable development are considered and policy guidance from the United Nations (UN), the European Union (EU) and the nation State level evaluated for its relevance to airport decision making. An attempt is made to reconcile definitions and interpretations before an idealized representation of a sustainable airport is presented. Mechanisms by which this may be actualized are then suggested. A need for improved theoretical knowledge is identified but research is also necessary on application and localization procedures for sustainable development.Professor James Longhurst is Head of Department of Environmental Health and Science at UWE, Bristol. Until recently he was the Director of the Atmospheric Research and Information Centre. David Gibbs is Professor of Human Geography at the University of Hull, UK. David Raper is Deputy Director and D.E. Conlan Environmental Projects Manager in the Atmospheric Research and Information Centre, Manchester Metropolitan University, UK.  相似文献   
74.
Summary Sustainable development has increasingly come to be seen as a concept which can reconcile the tensions between economic development and environmental protection. However, the concept is a vague one and little work has been undertaken to examine the practical implications of adopting sustainable development as a guiding principle. This paper examines how sustainable development can be defined, and some of the contradictions involved with the concept. The policy implications of sustainable development are examined, with a particular emphasis on industry and employment.His research interests are in sustainable development and local economic development. The work on which this paper is based was undertaken for the Centre for Local Economic Strategies in Manchester.  相似文献   
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There exists a clear imperative across the EU and within the UK towards the enhanced integration of community knowledge in environmental and health decision-making processes. The underlying social force that underpins this dynamic is the drive for a more accountable, transparent and publicly acceptable decision-making arena. However, relatively little research has been undertaken on the evaluation of local air quality management consultation in particular. In this context, the paper presents an evaluation of evidence resulting from questionnaire survey and case study research undertaken in the first round of the statutory process of local air quality management (LAQM), in which local authorities are required to consult on their air quality findings and intentions. We suggest that local authority perceptions of the relative abilities of differing stakeholders' grasp of air quality science, the process that translates that science into policy, and the institutional and organizational status of stakeholders (i.e. whether they are statutory or non-statutory stakeholders) may tend to transitively determine the choice of consultation methods used, the communication strategies chosen and the relative integration of stakeholder feedback into the LAQM decision-making process. In order to interrogate this potentially problematic chain of risk communication events, a preliminary conceptual model has been developed to enable the interrogation of the pathways through, and the obstacles to, the translation of air quality knowledge. The task is to unveil the sequential chains of association that comprise the LAQM risk communication process.  相似文献   
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Characterising sources and sinks of rural VOC in eastern France   总被引:2,自引:0,他引:2  
Fifty non-methane hydrocarbons (NMHC) and seventeen carbonyl compounds were measured at a French rural site from 1997 to 2001, as part of the EMEP programme. Data handling was based on an original source-receptor approach. First, the examination of the levels and trends was completed by the comparison of the seasonal distribution of rural and urban VOC/acetylene ambient ratios. This analysis has shown that most of the compounds derived from mixing and photochemical transformation of mid-range transported urban pollutants from the downwind urban area. Then, identified sources and sinks were temporally apportioned. Urban air masses mixing explains, at least, 80% of the wintertime levels of anthropogenic NMHC and isoprene. In summer, photochemistry dominates the day-to-day distribution of anthropogenic NMHC whilst summertime isoprene is also controlled by in-situ biogenic emissions. Then, the results of C(1)-C(3) carbonyls were discussed with respect to their direct biogenic and anthropogenic emissions and photochemical production through the [carbonyl/auto-exhaust tracers] emission ratio. Diluted vehicle exhaust emissions mainly contribute to the total content of lower aldehydes in winter while other processes control lower ketones. Secondary production is predominant in summer with at least a 50% high intensity. Its dependence upon temperature and radiation is also demonstrated. Finally, the importance of the primary and secondary biogenic production of acetone and formaldehyde is assessed. In particular, biogenic contribution would explain 37 +/- 25% of acetone levels in summer.  相似文献   
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Accurate estimates of male reproductive success are essential to understanding the evolution of polyandrous mating systems. Here, we use multilocus DNA fingerpinting to assess parentage in an island population of Tasmanian native hens (Tribonyx mortierii), which often live in multi-male and/or multi-female social groups. This isolated population presented special challenges to this technique because it was artificially founded from a small number of individuals in the recent past. DNA profiles from four multilocus minisatellite probes were analyzed for adults and offspring from six social groups using two methods: (1) significance of band-sharing coefficients and (2) distribution among a group's offspring of fragments unique to certain adults. Traditional band-sharing analyses did not provide sufficient resolution to establish parentage in this population due to the high level of band-sharing between adults within groups. In contrast, the distribution of unique fragments suggests that in most cases, all offspring within a group have the same male and female genetic parents, so that monogamy may be the predominant genetic mating system of this species. This forces a rexamination of the evolutionary basis of polyandry in these birds. It also demonstrates some of the difficulties in using these highly polymorphic genetic markers for parentage analyses when putative parents are closely related.  相似文献   
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