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91.
The results of an empirical study intoperceptions of the treatment of farm animals inthe Netherlands are presented. A qualitativeapproach, based on in-depth interviews withmeat livestock farmers and consumers was chosenin order to assess motivations behindperceptions and to gain insight into the waypeople deal with possible discrepancies betweentheir perceptions and their daily practices.Perceptions are analyzed with the help of aframe of reference, which consists ofvalues, norms, convictions, interests, andknowledge.The perceptions of the interviewed farmersare quite consistent and without exceptionpositive: according to them, nothing is wrongwith animal welfare in livestock breeding. Theperceptions of the consumers we interviewed aremore divergent, but generally negative. Bothgroups show ambivalence as a result ofdiscrepancies between perceptions and behavior.Although the consumers share the impressionthat the living conditions of livestock animalsare far from optimal, most of them still buyand eat meat from the meat industry. Thefarmers believe the welfare of their animals isgood, but, as frequent defensive utterancesshow, they feel uncomfortable with expressed orunexpressed accusations of mistreating animals.The ways the respondents deal with thisambivalence were analysed by drawing ontheories of dissonance reduction and distancing devices.Catherine and Raphaël Larrère(Larrère and Larrère, 2000) argue thatanimal rearing is a hierarchical relationshipwhose rules are to be found in the fiction of adomestic contract. We argue that the questionis not whether there should be a domesticcontract, because such a contract seems alreadyaccepted. However, since values and normsdiffer widely, not only among meat livestockfarmers and consumers, but also amongconsumers, the question remains as to whosevalues and norms should form the basis of thedomestic contract.  相似文献   
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Fate of 14C-bisphenol A in soils   总被引:8,自引:0,他引:8  
Fent G  Hein WJ  Moendel MJ  Kubiak R 《Chemosphere》2003,51(8):735-746
Bisphenol A (BPA; 2,2-(4,4(')-dihydroxydiphenyl)propane) is predominantly used as an intermediate in the production of polycarbonate plastics and epoxy resins. Traces of BPA released into the environment can reach the soil via application of sewage sludge from wastewater treatment systems that receive wastewaters containing BPA, or from leachate from uncontrolled landfills. The biodegradability of BPA has been previously investigated in several studies designed to simulate surface waters and biological wastewater treatment systems. However, there is little information available about the fate of BPA in soil. Therefore, laboratory soil degradation and batch adsorption studies were conducted with 14C-BPA and four soils according to international guidelines. The soils represented a broad range of physico-chemical properties. An important result of the degradation study was that, independent of the soil type, 14C-BPA was rapidly dissipated and not detectable in soil extracts following 3 days of incubation. Based on this result, a dissipation half-life of less than 3 days was estimated. The major route of dissipation of 14C-BPA in soil was the formation of bound residues that could not be recovered by exhaustive Soxhlet extraction. 14C-BPA was also shown to be transiently converted to up to five metabolites, but within 3 days, neither 14C-BPA nor 14C-metabolites were detectable in the soils. After 120 days incubation, significant amounts (up to 20% of the radioactivity applied) of the parent compound were recovered as 14CO(2). Soil adsorption experiments indicated that the distribution coefficients (K(oc)) were between 636 and 931, classifying BPA as having low mobility for all tested soils. From the results of this study, it was concluded that if BPA reaches the soil compartment, it is not expected to be stable, mobile, or bioavailable.  相似文献   
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Digital image analysis can be used to assist or complement visual perception. In quantifying light intensities it is superior to the human visual system and therefore is an appropriate and useful tool for research. Using microphotometry as an example the physical bases of digital image analysis are explained and the applications of this measuring technique to biochemical analysis are demonstrated.  相似文献   
97.
Encroachment of tall grasses and shrubs in coastal dunes has resulted in loss of vegetation heterogeneity. This is expected to have negative effects on animal diversity. To counteract encroachment and develop structural heterogeneity grazing is a widely used management practice. Here, we aim to functionally interpret changes in vegetation composition and configuration following grazing management on habitat suitability for sand lizards. Aerial photographs taken over a period of 16 years were used to quantify changes in vegetation composition. A GIS-based method was developed to calculate habitat suitability for sand lizards in a spatially explicit manner, encompassing differences in vegetation structure and patch size. From 1987 to 2003 dune vegetation shifted from small patches of moss and sand to larger patches covered by shrubs and grasses. Grazing management did not have any significant effect on the overall level of heterogeneity, measured as habitat suitability for sand lizards. However, on a more local scale highly suitable patches in 1987 were deteriorating whereas unsuitable patches became more suitable in 2003. This inversion results from a broad shift with shrubs being a limiting habitat element in 1987 to sandy patches being the limiting element in 2003. Future changes are believed to negatively impact sand lizards. The habitat suitability model has proven to be a useful tool to functionally interpret changes in coastal dune vegetation heterogeneity from an animal’s perspective. Further research should aim to include multiple species operating on different scale levels to fully capture the natural landscape dynamics.  相似文献   
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Sharks and other large predators are scarce on most coral reefs, but studies of their historical ecology provide qualitative evidence that predators were once numerous in these ecosystems. Quantifying density of sharks in the absence of humans (baseline) is, however, hindered by a paucity of pertinent time-series data. Recently researchers have used underwater visual surveys, primarily of limited spatial extent or nonstandard design, to infer negative associations between reef shark abundance and human populations. We analyzed data from 1607 towed-diver surveys (>1 ha transects surveyed by observers towed behind a boat) conducted at 46 reefs in the central-western Pacific Ocean, reefs that included some of the world's most pristine coral reefs. Estimates of shark density from towed-diver surveys were substantially lower (<10%) than published estimates from surveys along small transects (<0.02 ha), which is not consistent with inverted biomass pyramids (predator biomass greater than prey biomass) reported by other researchers for pristine reefs. We examined the relation between the density of reef sharks observed in towed-diver surveys and human population in models that accounted for the influence of oceanic primary productivity, sea surface temperature, reef area, and reef physical complexity. We used these models to estimate the density of sharks in the absence of humans. Densities of gray reef sharks (Carcharhinus amblyrhynchos), whitetip reef sharks (Triaenodon obesus), and the group "all reef sharks" increased substantially as human population decreased and as primary productivity and minimum sea surface temperature (or reef area, which was highly correlated with temperature) increased. Simulated baseline densities of reef sharks under the absence of humans were 1.1-2.4/ha for the main Hawaiian Islands, 1.2-2.4/ha for inhabited islands of American Samoa, and 0.9-2.1/ha for inhabited islands in the Mariana Archipelago, which suggests that density of reef sharks has declined to 3-10% of baseline levels in these areas.  相似文献   
100.
MODELKEY     
The EU Water Framework Directive (WFD) requires the achievement of good ecological and chemical status in European river basins. However, evidence is increasing that a majority of European water bodies will not achieve this goal. Nutrient emissions and related eutrophication together with hydromorphological alterations have been suggested as the major driving forces of this insufficient ecological status. MODELKEY (511237 GOCE, FP6) provides strong evidence that toxic chemicals also affect the ecological status of European rivers. This was demonstrated in the case study rivers Elbe, Scheldt and Llobregat on different scales. This paper summarises key findings of MODELKEY including recommendations for WFD implementation. We ? provide evidence of toxic stress in aquatic ecosystems, ? provide evidence that impairment of ecological status results from impact of multiple stressors, ? suggest a tiered approach to assess impact of chemicals on ecological status, ? suggest a new approach for deriving candidate compounds for monitoring and prioritisation, ? call for consideration of bioavailability and bioaccumulation in chemical status assessments, ? suggest improvements for WFD water quality monitoring programmes, ? provide new integrated tools for basin-scale risk assessment and decision making, ? developed a Decision Support System to support river basin management. These key results will be presented in a series of ten integrated sections; for the scientific details please refer to publications listed on the MODELKEY website (http://www.modelkey.org/). This article also looks beyond MODELKEY and proposes a combination of MODELKEY diagnostic tools with recent ecological methods to further improve effectiveness of river basin management.  相似文献   
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