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21.
This paper reports on a major study of the incidence of indicator organisms and pathogens found within Class B biosolids within 21 samplings from 18 wastewater treatment plants across the United States. This is the first major study of its kind since the promulgation of the USEPA Part 503 Rule in 1993, and includes samples before and after the Part 503 Rule was promulgated. National distributions collected between 2005 and 2008 show that the incidence of bacterial and viral pathogens in Class B mesophilic, anaerobically digested biosolids were generally low with the exception of adenoviruses, which were more prevalent than enteric viruses. No Ascaris ova were detected in any sample. In contrast, indicator organism numbers were uniformly high, regardless of whether they were bacteria (fecal coliforms) or viruses (phage). Indicators were not correlated with pathogen loads. Historic distributions were collected between 1988 and 2006 at one location in Tucson, AZ. By comparing data collected before and after 1993, the influence of the USEPA Part 503 Rule on indicator and pathogen levels within Class B biosolids can be inferred. In general, the bacterial indicators total and fecal coliforms decreased from the 1980s to present. Enteric virus concentrations after 1993 are much lower than those reported in other studies in the 1980s, although our values from 1988 to 1993 are not significantly different from our values obtained from 1994 to 2006. Presumably this is due to better and more consistent treatment of the wastewater, illustrating that the Part 503 Rule has been effective in reducing public exposure to pathogens relative to 17 yr ago. The percent reduction of both indicators and pathogens during anaerobic mesophilic digestion was between 94 and 99% for all organisms, illustrating that such treatment is effective in reducing pathogen loads.  相似文献   
22.
The purpose of this paper is to consider the vision for public participation in water resources management embedded in Kenya's 2002 Water Act, as it relates to pastoralists. The Act envisions that responsibility for management of water resources at the local level will be devolved to community-level bodies. Our approach was qualitative and included interviews with government officials and Gabra pastoralists, observation of and participation in traditional Gabra korra meetings and focus group discussions. We conclude that the ‘institutional model’ of participation being pursued through the creation of Water Resource User Associations is particularly problematic for mobile pastoralists such as the Gabra, and we suggest an alternative strategy that would focus on the fostering of deliberation processes.  相似文献   
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To test the hypothesis that stable isotope ratios from marine organisms vary, the δ15N and δ13C values from fish and squid collected in Alaskan waters were measured across years (1997, 2000, and 2005), seasons, geographic locations, and different size/age classes, and between muscle tissue and whole animals. Temporal, geographic, and ontogenetic differences in stable isotope ratios ranged from 0.5–2.5‰ (δ15N) to 0.5–2.0‰ (δ13C). Twenty-one comparisons of stable isotope values between whole organisms and muscle tissue revealed only four small differences each for δ15N and δ13C, making costly and space prohibitive collection of whole animals unnecessary. The data from this study indicate that significant variations of stable isotope values from animals in marine systems necessitates collection of prey and predator tissues from the same time and place for best interpretation of stable isotope analysis in foraging ecology studies.  相似文献   
25.
This paper explores the concept of packaging stewardship to establish methods that could be used formatively in the development of packaging stewardship programmes or in a post hoc fashion after their implementation. It argues that an independent set of values criteria for evaluation are important at this juncture because of the number of jurisdictions considering packaging stewardship programmes. Additional urgency is added by industry's tendency to promote sales of products through their participation in such programmes. A framework is developed that provides a pathway for future packaging programmesto converge on stewardship.The framework is developed around the notion of a steward, as explored by Lerner and Bookchin, and the principles proposed for the Canadian National Packaging Protocol. The frameworkis illustrated with examples from Germany, France, Belgium, the United Kingdom and Canada.  相似文献   
26.
Zooplankton and their phytoplankton prey form the basis of the marine food web, yet historically it has been difficult to discern species-specific trophic interactions. Molecular techniques provide opportunities to obtain taxonomic data where the traditional methodologies for gut content analysis lack resolution. The large subunit gene of RubisC/O, rbcL, was utilized as a molecular marker for the identification of prey species in calanoid copepods. Clone libraries were generated from DNA extracted from seawater and whole copepods during a transect cruise on the northern Gulf of Mexico shelf. Sequence data analysis provided evidence of diatoms, nanoplankton-sized chlorophytes, and cyanobacteria in DNA extracted from whole copepods. These data demonstrate that rbcL can be a useful marker for the identification of copepod phytoplankton prey. Combining the described approach with quantitative techniques such as quantitative PCR will provide opportunities for the assessment of species-specific predator–prey interactions.  相似文献   
27.
Considerable attention is now being given to the role and importance of education and learning implications of participatory resource and environmental governance. The contention is that such learning has the potential to transform behaviour, and in the case of resource management, may help change current patterns in resource use towards a more sustainable social-ecological system. Our purpose is to establish the opportunities for learning afforded to those participating in local level resource management committees in two Cambodian fishing communities and consider the learning outcomes from such opportunities. Our approach was qualitative and used a case study design. The findings establish a wide range of committee resource management activities that resulted in both instrumental (e.g., learning about administrative procedures) and communicative (e.g., insights into the need to conserve mangroves) learning. It was revealed that such learning can lead to changes in behaviour at the community level (e.g., managing local waste). Our findings also indicated a number of motivators and enablers of learning such as opportunities for dialogue, leadership and the presence of declining resources.  相似文献   
28.
Maguire primrose (Primula maguirei) is a geographically restricted plant species, known only from a 19-km stretch of Logan Canyon in northern Utah (U.S.A.). We examined variation at 13 isozyme loci from 25 individuals of P. maguirei at each of eight sites. At individual loci we detected no statistically significant deviations from Hardy-Weinberg proportions within sites (subpopulations). However, some loci were almost fixed for different alleles at the upper reaches of the species' range relative to populations approximately 10 km away. The total mean gene diversity among loci was 0.22, of which 55% was partitioned within subpopulations, 0.7% among subpopulations within populations (100 m spatial scale), 3% among populations separated by about 1 km, and 41% between an Upper Canyon group of populations and a Lower Canyon group (10-km scale). We detected no gametic disequilibria among loci within subpopulations (and populations). Two hypotheses are proposed to explain the results: (1) past genetic bottlenecks and (2) genetic divergence as a by-product of local adaptations to different habitats. Regardless of the causes of allozymic differentiation, our results suggest that plans for artificial establishment or reestablishment of P. maguirei populations should use source populations within 1 km of the establishment site. This study emphasizes the potential use of data on population genetic structure for managing and monitoring rare species.  相似文献   
29.
在如今超过1 500种在用原料药中,环境中发现几率明确和对环境影响明确的原料药所占比例很小。由于很难监管所有在用原料药,众多先前的研究提议将原料药按照受关注程度排序,从而可以将研究资源集中于那些最受瞩目的药物。然而这些研究都存在局限性,本文从之前优先性方法的实践经验出发,提出了一种更为全面的原料药排序方法。该方法基于对水生生物、土壤生物、鸟类、野生哺乳动物和人类的风险,综合考虑了食物链顶端存在的生态毒理学研究终点和由这些治疗性药物作用机制带来的非顶端效果。对于在英国社区以及医院设置中使用的146种活性药物的分析可以更为详细地说明该方法的运用。根据这一方法,我们将16种化合物列为优先考虑的药物。这些药物包括了抗生素、抗抑郁药、抗炎药、抗糖尿病药、抗肥胖药、雌激素类化合物以及相关的代谢产物。我们建议这种优先性方法在将来可以更广泛地应用于世界上不同的地区。
精选自Jiahua Guo, Chris J. Sinclair, Katherine Selby, Alistair B.A. Boxall. Toxicological and ecotoxicological risk based prioritisation of pharmaceuticals in the natural environment. Environmental Toxicology and Chemistry: Volume 35, Issue 7, pages 1550–1559, July 2016. DOI: 10.1002/etc.3319
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3319/full
  相似文献   
30.
Potential use of reservoirs and flooded fields stocked with aquatic plants for reduction of the nutrient levels of organic soil drainage water was evaluated. The treatment systems include 1) a large single reservoir (R1) stocked with waterhyacinth (Eichhornia crassipes), elodea (Egeria densa), and cattails (Typha sp.) in series; 2) three small reservoirs in series with waterhyacinth (R2), elodea (R3), and cattails (R4), grown in independent reservoirs; 3) a control reservoir (R5) with no cultivated plants; 4) a large single flooded field planted to cattails; 5) three small flooded fields in a series planted to cattails; and 6) a flooded field with no cultivated plants. Drainage water was pumped daily (6 hours a day, and 6 days a week) into these systems for a period of 27 months at predetermined constant flow rates. Water samples were collected at the inlet and outlet of each treatment system and analyzed for N and P forms.The series of reservoirs stocked with aquatic plants functioned effectively in the removal of N and P from agricultural drainage water, compared to a single large reservoir. Allowing the water to flow through the reservoir stocked with waterhyacinth plants with a residence time of 3.6 days was adequate to remove about 50% of the incoming inorganic N. Allowing the water to flow through a series of two small reservoirs, R2 and R3, with a residence time of 7.3 days was necessary to remove about 60% of the incoming ortho-P. Flooded fields were effective in the removal of inorganic N, but showed poor efficiency in the removal of ortho-P.Florida Agricultural Experiment Stations Journal Series No. 2320.  相似文献   
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