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21.
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   
22.
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   
23.
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   
24.
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   
25.
Planetary Stewardship in an Urbanizing World: Beyond City Limits   总被引:1,自引:0,他引:1  
Cities are rapidly increasing in importance as a major factor shaping the Earth system, and therefore, must take corresponding responsibility. With currently over half the world’s population, cities are supported by resources originating from primarily rural regions often located around the world far distant from the urban loci of use. The sustainability of a city can no longer be considered in isolation from the sustainability of human and natural resources it uses from proximal or distant regions, or the combined resource use and impacts of cities globally. The world’s multiple and complex environmental and social challenges require interconnected solutions and coordinated governance approaches to planetary stewardship. We suggest that a key component of planetary stewardship is a global system of cities that develop sustainable processes and policies in concert with its non-urban areas. The potential for cities to cooperate as a system and with rural connectivity could increase their capacity to effect change and foster stewardship at the planetary scale and also increase their resource security.  相似文献   
26.
A recently developed photometer utilizes near-forward scattered light to count and size aerosol particles in the diameter range 0.3-17 μ. The particles are drawn through a 1-cu mm illuminated volume without entering the body of the optical chamber. Hence, purging is almost instantaneous, and number concentrations below 1,000,000/cu ft give less than 3% coincidences. The scattered light pulse from each particle is detected by a photomultiplier tube. The resultant voltage pulses are amplified, measured by a series of ten discriminator circuits, and stored in a series of ten 5-decade electronic counters. At the end of a chosen period ranging from 1/3 to 30 min, a digital printer prints the number of particles at each diameter. At the end of the printout, the procedure automatically recycles. The instrument provides ten size classifications, each successively having a width ratio of 1.5 to 1. Greater precision is seldom practical since most aerosols contain particles of different refractive index, color, and shape, all of which affect the intensity of the scattered light. Calibration is accomplished with aerosols of uniform size such as spray-dried polystyrene and other latex suspensions, supplemented by calculations based on the Mie theory of light scattering.  相似文献   
27.
Generic water quality guidelines (WQGs) are developed by countries/regions as broad scale tools to assist with the protection of aquatic ecosystems from the impacts of toxicants. However, since generic WQGs cannot adequately account for the many environmental factors that may affect toxicity at a particular site, site-specific WQGs are often needed, especially for high environmental value ecosystems. The Australian and New Zealand Guidelines for Fresh and Marine Water Quality provide comprehensive guidance on methods for refining or deriving WQGs for site-specific purposes. This paper describes three such methods for deriving site-specific WQGs, namely: (1) using local reference water quality data, (2) using biological effects data from laboratory-based toxicity testing, and (3) using biological effects data from field surveys. Two case studies related to the assessment of impacts arising from mining operations in northern Australia are used to illustrate the application of these methods. Finally, the potential of several emerging methods designed to assess thresholds of ecological change from field data for deriving site-specific WQGs is discussed. Ideally, multiple lines of evidence approaches, integrating both laboratory and field data, are recommended for deriving site-specific WQGs.  相似文献   
28.
Abstract: Species occurrence in a habitat patch depends on local habitat and the amount of that habitat in the wider landscape. We used predictions from empirical landscape studies to set quantitative conservation criteria and targets in a multispecies and multiscale conservation planning effort. We used regression analyses to compare species richness and occurrence of five red‐listed lichens on 50 ancient oaks (Quercus robur; 120–140 cm in diameter) with the density of ancient oaks in circles of varying radius from each individual oak. Species richness and the occurrence of three of the five species were best explained by increasing density of oaks within 0.5 km; one species was best explained by the density of oaks within 2 km, and another was best predicted by the density of oaks within 5 km. The minimum numbers of ancient oaks required for “successful conservation” was defined as the number of oaks required to obtain a predicted local occurrence of 50% for all species included or a predicted local occurrence of 80% for all species included. These numbers of oaks were calculated for two relevant landscape scales (1 km2 and 13 km2) that corresponded to various species responses, in such a way that calculations also accounted for local number of oaks. Ten and seven of the 50 ancient oaks surveyed were situated in landscapes that already fulfilled criteria for successful conservation when the 50% and 80% criteria, respectively, were used to define the level of successful conservation. For cost‐efficient conservation, oak stands in the landscapes most suitable for successful conservation should be prioritized for conservation and management (e.g., grazing and planting of new oaks) at the expense of oak stands situated elsewhere.  相似文献   
29.
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   
30.
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
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