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281.
Communicating the process quality of ethically produced food effectively is of highest interest to policy makers, organizations, retailers and producers in order to enhance ethical food production and increase ethical label use. The objective of this paper is to unveil the effectiveness of different communication treatments in regard to changing purchase behavior of different consumer groups. Different communication material for beef produced according to consumer expectations was compiled and applied in a consumer survey—incorporating a choice experiment and a questionnaire—with 676 respondents in three cities of Germany. A Latent Class Mixed Logit Model was basis to identify different consumer segments and their response to the different communication treatments. The effects of different communication treatments unveil the importance to address information in an objective manner. Target groups could be enlarged through the assessment of clear, objective information. Moreover, most consumers were more likely to refrain from choosing a cheap beef product from conventional, barn-based rearing. Hence, consumers might be interested in reducing their overall consumption of beef and prefer the consumption of high value ethical beef with less frequency. Producers, market actors and policy makers should realize that a high share of consumers, not only smaller target groups, value ethical food and may be ready to change their consumption habits, if they are adequately informed.  相似文献   
282.
In Axelved, Denmark, an abandoned gas filling station serves as a test field for phytoremediation. Laboratory studies accompany the project. The toxicity of fresh and weathered gasoline and diesel to willow and poplar trees was studied by use of a tree transpiration toxicity test. The correlation between diesel content in soil and decrease in willow tree transpiration (Salix viminalis x schwerinii) was highly significant (r 2=0.81, n=19). the EC50 (50% inhibition of transpiration) for the sum of hydrocarbons (HC) was determined to be 3910 mg/kg (95% confidence interval from 2900 to 5270 mg/kg). The EC10 was 810 mg/kg (95% confidence interval 396 to 1660 mg/kg). The results were verified with artificially mixed diesel and gasolinecontaminated soils and two willow and one poplar species (S. viminalis, S. alba andPopulus nigra). The degradation of radiolabeledm-xylene was studied with and without willows. The compound was readily degraded. Willow trees accelerated the elimination, but mainly due to the volatilization ofm-xylene. Model studies provided the result that biodegradation in soil is the fastest elimination process at the site, but it is limited by the availability of electron acceptors. The pollutants are almost persistent in the groundwater, but in aerated soil, 10000 mg/kg hydrocarbons at 1 m depth are degraded within 13 years. The main effect of willows on the pollutants’ persistence is that willows transpire water, lower the groundwater level and aerate the soil, hereby speeding up biodegradation.  相似文献   
283.
In the discussion about consequences of the release of genetically modified (GM) crops, the meaning of the term “environmental damage” is difficult to pin down. We discuss some established concepts and criteria for understanding and evaluating such damages. Focusing on the concepts of familiarity, biological integrity, and ecosystem health, we argue that, for the most part, these concepts are highly ambiguous. While environmental damage is mostly understood as significant adverse effects on conservation resources, these concepts may not relate directly to effects on tangible natural resources but rather to parameters of land use or ecological processes (e.g., the concept of biological integrity). We stress the importance of disclosing the normative assumptions underlying damage concepts and procedures for the evaluation of damages by GM crops. A conceptualization of environmental damage should precede its operationalization. We recommend an unambiguous definition for damage developed earlier and recommend that evaluation criteria be based on this. However, a general damage definition cannot replace case-specific operationalization of damage, which remains an important future challenge.  相似文献   
284.
The first generation of WFD River Basin Management Plans is now available. This is a formidable achievement and a great step towards addressing Europe's deteriorated river systems. However, plans are only words: only the actual implementation of the selected measures will result in achievement of good ecological and chemical status. The WFD Lille 2010 Conference pointed out that a lot of new, but so far unused scientific knowledge is available to improve the effectiveness of selected measures or to inspire the introduction of complementary measures. Furthermore, the complexity in terms of the functioning of the water system, its interaction with the socio-economic system and the uncertain consequences of climate change, urges a 'learning-by-doing' approach. This approach should be applied in well-designed, -coordinated and -monitored learning catchments.  相似文献   
285.
Results of a field experiment (please refer to Warrelmann et al. 2000a) document TNT-degradation and regeneration after the establishment of a phytoremediation. Various approaches are included in a complex monitoring system, which are conducted in the field (nitroaromatics in soil, seepage water, and plants; soil fauna; soil fungi; decomposition) as well as in the lab (a battery of 6 biotests). The data document a high heterogeneity of the TNT-contamination, a rapid initial decrease and a mediocre displacement of nitroaromatics in plants and seepage water. The initial rapid transformation of TNT to aminodinitrotoluenes ceases significantly after 3 months. Results of the biotest battery allow a sophisticated assessment of soil toxicity; the results from the soil ecological field investigations make the long-term effects of TNT-contamination likely. In a third part of the series of articles, a synopsis and judgement of the project will be delivered.  相似文献   
286.
Carbonaceous soil amendments are applied to contaminated soils and sediments to strongly sorb hydrophobic organic contaminants (HOCs) and reduce their freely dissolved concentrations. This limits biouptake and toxicity, but also biodegradation. To investigate whether HOCs sorbed to such amendments can be degraded at all, the desorption and biodegradation of low concentrations of 14C-labelled phenanthrene (?5 μg L?1) freshly sorbed to suspensions of the pure soil amendments activated carbon (AC), biochar (charcoal) and compost were compared. Firstly, the maximum abiotic desorption of phenanthrene from soil amendment suspensions in water, minimal salts medium (MSM) or tryptic soy broth (TSB) into a dominating silicone sink were measured. Highest fractions remained sorbed to AC (84 ± 2.3%, 87 ± 4.1%, and 53 ± 1.2% for water, MSM and TSB, respectively), followed by charcoal (35 ± 2.2%, 32 ± 1.7%, and 12 ± 0.3%, respectively) and compost (1.3 ± 0.21%, similar for all media). Secondly, the mineralization of phenanthrene sorbed to AC, charcoal and compost by Sphingomonas sp. 10-1 (DSM 12247) was determined. In contrast to the amounts desorbed, phenanthrene mineralization was similar for all the soil amendments at about 56 ± 11% of the initially applied radioactivity. Furthermore, HPLC analyses showed only minor amounts (<5%) of residual phenanthrene remaining in the suspensions, indicating almost complete biodegradation. Fitting the data to a coupled desorption and biodegradation model revealed that desorption did not limit biodegradation for any of the amendments, and that degradation could proceed due to the high numbers of bacteria and/or the production of biosurfactants or biofilms. Therefore, reduced desorption of phenanthrene from AC or charcoal did not inhibit its biodegradation, which implies that under the experimental conditions these amendments can reduce freely dissolved concentration without hindering biodegradation. In contrast, phenanthrene sorbed to compost was fully desorbed and biodegraded.  相似文献   
287.
288.
Thousands of chemicals are on the market, but only in a few exceptional cases is it known where these chemicals remain in the environment and what effects they are able toexert in correlation to their environmental concentration. In addition to monitoring the actual concentrations of chemicals in the environment, it is necessary to establish an environmental specimen banking program which will, in the future, make possible the retrospective monitoring of chemicals. The feasibility of such a program is being studied in a joint U.S.-German pilot project. The German project is described here, including its organizational structure, technical and scientific considerations, and methods of specimen selection.  相似文献   
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290.
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