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161.
Environmental surveillance of poliovirus (PV) plays an important role in the global program for eradication of wild PV. The bag-mediated filtration system (BMFS) was first developed in 2014 and enhances PV surveillance when compared to the two-phase grab method currently recommended by the World Health Organization (WHO). In this study, the BMFS design was improved and tested for its usability in wastewater and wastewater-impacted surface waters in Nairobi, Kenya. Modifications made to the BMFS included the size, color, and shape of the collection bags, the filter housing used, and the device used to elute the samples from the filters. The modified BMFS concentrated 3–10 L down to 10 mL, which resulted in an effective volume assayed (900–3000 mL) that was 6–20 times greater than the effective volume assayed for samples processed by the WHO algorithm (150 mL). The system developed allows for sampling and in-field virus concentration, followed by transportation of the filter for further analysis with simpler logistics than the current methods. This may ultimately reduce the likelihood of false-negative samples by increasing the effective volume assayed compared to samples processed by the WHO algorithm, making the BMFS a valuable sampling system for wastewater and wastewater-impacted surface waters.  相似文献   
162.
Going beyond the relation of work and family, the present three‐wave longitudinal study spanning one year assessed different forms of conflict and facilitation between leisure and the life domains work and family and their relation to subjective well‐being. A sample of N = 277 employed men and women reported their perceived conflict and facilitation between leisure, work, and family and subjective well‐being. Results suggest that leisure is a source of facilitation for work and family, and, at the same time, a major recipient of conflict from work and family. Moreover, leisure conflict was negatively correlated and leisure facilitation was positively associated with concurrent subjective well‐being. Both conflict and facilitation between all three life domains remained highly stable over the course of one year. Only few and non‐systematic lagged effects were found, indicating that the variance of the stability of the constructs and their relations over time leave little room for longitudinal predictions. Taken together, the study demonstrates that, similar to work–family relations, conflict and facilitation with the leisure domain are also associated with subjective well‐being and remain highly stable over the course of a year in the lives of young and middle‐aged adults. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
163.
Adaptation to ecologically heterogeneous environments can drive speciation. But what mechanisms maintain reproductive isolation among locally adapted populations? Using poeciliid fishes in a system with naturally occurring toxic hydrogen sulfide, we show that (a) fish from non-sulfidic sites (Poecilia mexicana) show high mortality (95 %) after 24 h when exposed to the toxicant, while locally adapted fish from sulfidic sites (Poecilia sulphuraria) experience low mortality (13 %) when transferred to non-sulfidic water. (b) Mate choice tests revealed that P. mexicana females exhibit a preference for conspecific males in non-sulfidic water, but not in sulfidic water, whereas P. sulphuraria females never showed a preference. Increased costs of mate choice in sulfidic, hypoxic water, and the lack of selection for reinforcement due to the low survival of P. mexicana may explain the absence of a preference in P. sulphuraria females. Taken together, our study may be the first to demonstrate independent—but complementary—effects of natural and sexual selection against immigrants maintaining differentiation between locally adapted fish populations.  相似文献   
164.
种衣剂中使用的杀虫剂会影响鸟类对种子的消耗量,从而影响鸟类的实际暴露风险。虽然量化这种对消耗量的影响目前不被考虑在环境风险评估中,但这是一个潜在的选择,例如在比较不同农药的暴露风险时应予以考虑。这种方法可以突出用于防止鸟类服用致死或亚致死剂量的杀虫剂。为了制定一个标准,我们在已建立的笔试方法的基础上开发了一个室内测试程序,包括饥饿期的“两选择”和“无选择”阶段。测试期间采用动物福利的最高标准。利用统计方法确定最合适的重复次数并分析最终结果。杀虫剂对种子消耗量的影响用处理后种子与未处理种子消耗的比率表示。该消耗因子可作为种子处理的鸟类风险评估中的回避因子。 作为案例,我们提出了一个获得绿雀(Carduelis chloris)和日本鹌鹑(Coturnix japonica)对未处理和使用杀真菌剂处理的油菜籽(Brassica napus)的种子和特定物种消耗量因子的试验程序。总体来说,两种鸟类的体质都没有受到试验程序的负面影响。试验程序适用于显示预期消耗模式的差异,例如在“两选择”试验中比在“无选择”试验中对经过杀真菌剂处理的种子有更高的避免性。而种子消耗量在不同物种和杀真菌剂处理组有差别,这使得我们可以对不同杀真菌剂的规避效应进行排序。使用本文所提出的标准程序可以针对更多鸟类物种得到具有可比性的农药和物种特定的消费因子。  相似文献   
165.
There is increasing interest among scholars in producing information that is useful and usable to land and natural resource managers in a changing climate. This interest has prompted transitions from scientist- to stakeholder-driven or collaborative approaches to climate science. A common indicator of successful collaboration is whether stakeholders use the information resulting from the projects in which they are engaged. However, detailed examples of how stakeholders use climate information are relatively scarce in the literature, leading to a challenge in understanding what researchers can and should expect and plan for in terms of stakeholder use of research findings. Drawing on theoretical, typological, and evaluation insights from the field of information use, we examine stakeholder use of climate information emerging from 13 collaborative climate science projects conducted in the western United States between 2012 and 2016. Three primary types of use emerge from our findings—conceptual, instrumental, and justification—reflecting common typologization of information use. Conceptual use was the most predominant. We suggest that researcher awareness of this typology can enable more systematic understanding of what project outputs stakeholders use and impacts of those outputs, giving way to new areas of inquiry and aiding in the conceptualization and design of climate information products for land and natural resource managers.  相似文献   
166.
A protocol was developed to extract, fractionate, and quantitatively analyze periphyton extracellular polymeric substances (EPS), which obtains both information on the molecular weight (M r) distribution and protein and polysaccharide content. The EPS were extracted from freshwater periphyton between July and December 2011. Organic carbon (OC) compounds from different EPS extracts were analyzed using liquid chromatography-organic carbon detection–organic nitrogen detection (LC-OCD-OND), and total protein and polysaccharide content were quantified. Four distinct OC fractions, on the basis of M r, were identified in all extracts, corresponding to high M r biopolymers (≥80–4 kDa), degradation products of humic substances (M r not available), low M r acids (10–0.7 kDa), and small amphiphilic/neutral compounds (3–0.5 kDa). Low C/N ratios (4.3?±?0.8) were calculated for the biopolymer fractions, which represented 16–38 % of the measured dissolved organic carbon (DOC), indicating a significant presence of high M r proteins in the EPS. Protein and polysaccharide represented the two major components of EPS and, when combined, accounted for the measured DOC in extracts. Differences in specific OC fractions of EPS extracts over the course of the study could be quantified using this method. This study suggests that LC-OCD-OND is a new valuable tool in EPS characterization of periphyton.  相似文献   
167.
We review the available data that can be used to assess the potential impact of climate change on vegetation, and we use central Spitsbergen, Svalbard, as a model location for the High Arctic. We used two sources of information: recent and short-term historical records, which enable assessment on scales of particular plant communities and the landscape over a period of decades, and palynological and macrofossil analyses, which enable assessment on time scales of hundreds and thousands of years and on the spatial scale of the landscape. Both of these substitutes for standardized monitoring revealed stability of vegetation, which is probably attributable to the harsh conditions and the distance of the area from sources of diaspores of potential new incomers. The only evident recent vegetation changes related to climate change are associated with succession after glacial retreats. By establishing a network of permanent plots, researchers will be able to monitor immigration of new species from diversity 'hot spots' and from an abandoned settlement nearby. This will greatly enhance our ability to understand the effects of climate change on vegetation in the High Arctic.  相似文献   
168.
Many inhabitants of Berlin enjoy bathing in lakes and rivers during the summer. However, so far no data exist about who goes bathing and what quality bathers expect from bathing sites. In an online survey conducted during the summer of 2007 respondents were presented with a choice experiment concerning various attributes of bathing sites such as water quality or cleanliness of the beach. Applying both random parameter logit models as well as a latent class model reveals that unobserved taste heterogeneity is present among bathers, i.e. not all bathers would benefit equally from improving bathing sites. A test concerning preference consistency reveals high internal validity.  相似文献   
169.
Tetrakis-(4-sulfonatophenyl)porphyrin cobalt was identified as a highly-active reductive dechlorination catalyst for chlorinated ethylenes. Through batch reactor kinetic studies, degradation of chlorinated ethylenes proceeded in a step-wise fashion with the sequential replacement of Cl by H. For perchloroethylene (PCE) and trichloroethylene (TCE), the dechlorination products were quantified and the C2 mass was accounted for. Degradation of the chlorinated ethylenes was found to be first-order in substrate. Dechlorination trials with increasing catalyst concentration showed a linearly increasing pseudo first-order rate constant which yielded rate laws for PCE and TCE degradation that are first-order in catalyst. The dechlorination activity of this catalyst was compared to that of another water-soluble cobalt porphyrin under the same reaction conditions and found to be comparable for PCE and TCE.  相似文献   
170.
In this work, the phytoremediation potential of metalaxyl, a commonly used persistent, mobile and leachy fungicide, by Solanum nigrum L. plants was studied. The study revealed that this plant species can be used as an excellent metalaxyl phytoremediation tool, thus providing a cost effective and environmentally friendly clean technology for the decontamination of sites and effluents. As it can be sowed directly in the remediation site, is able to complete its life cycle without suffering major stress. Because it accumulates high amounts of the fungicide in the aboveground tissues, enables its concentration and proper disposal by cutting off the corresponding plant part. The study also suggests that the tolerance to metalaxyl is due to a suitable antioxidant response comprising proline accumulation and guaiacol peroxidase and glutathione-S-transferase enhanced activities, that reduce oxidative damage to the plant organs.  相似文献   
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