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The goal of this article is to contribute to the understanding of how the multiple, and sometimes conflicting, stakeholder perspectives and prevailing conditions (economic, geographic, etc.) in the implementation locality shape extended producer responsibility (EPR) “on the ground.” We provide an in‐depth examination of the implementation dimension of EPR in a specific case study by examining concrete activities at the operational front of the collection and recycling system, and probing the varying stakeholder preferences that have driven a specific system to its status quo. To this end, we conduct a detailed case study of the Washington State EPR implementation for electronic waste. We provide an overview of various stakeholder perspectives and their implications for the attainment of EPR policy objectives in practice. These findings shed light on the intrinsic complexity of EPR implementation. We conclude with recommendations on how to achieve effective and efficient EPR implementation, including improving design incentives, incorporating reuse and refurbishing, expanding product scope, managing downstream material flows, and promoting operational efficiency via fair cost allocation design.  相似文献   
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Although the importance of glutathione in protection against oxidative stress is well recognized, the role of physiological levels of glutathione and other endogenous antioxidants in protecting against exercise-induced oxidative stress is less clear. We evaluated the role of glutathione and selected antioxidant enzymes as determinants of lipid peroxidation at rest and in response to exercise in men (n = 13-14) aged 20-30 years, who cycled for 40 min at 60% of their maximal oxygen consumption (VO2max). Levels of plasma thiobarbituric acid reactive substances (plasma TBARS) and blood oxidised glutathione (GSSG) increased by about 50% in response to exercise. Mean blood reduced glutathione (GSH) decreased by 13% with exercise. Of the measured red blood cell (RBC) antioxidant enzyme activities, only selenium-dependent glutathione peroxidase (Se-GPX) activity rose following exercise. In univariate regression analysis, plasma TBARS levels at rest predicted postexercise plasma TBARS and the exercise-induced change in total glutathione (TGSH). Blood GSSG levels at rest were strongly determinant of postexercise levels. Multiple regression analysis showed blood GSH to be a determinant of plasma TBARS at rest. The relative changes in TGSH were determinant of postexercise plasma TBARS. In summary, higher blood GSH and lower plasma TBARS at rest were associated with lower resting, and exercise-induced, lipid peroxidation. Subjects with a favourable blood glutathione redox status at rest maintained a more favourable redox status in response to exercise-induced oxidative stress. Changes in blood GSH and TGSH in response to exercise were closely associated with both resting and exercise-induced plasma lipid peroxidation. These results underscore the critical role of glutathione homeostasis in modulating exercise-induced oxidative stress and, conversely, the effect of oxidative stress at rest on exercise-induced changes in glutathione redox status.  相似文献   
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Two lichen metabolites, rhizonaldehyde ( 1 ) and rhizonyl alcohol ( 2 ), were isolated from the acetone extract of Lobaria pulmonaria by chromatographic methods, and their chemical structures were determined by UV/VIS, IR, and 1D‐ and 2D‐NMR spectroscopic methods. The gastroprotective and in vivo antioxidant activities of extracts of L. pulmonaria and its metabolites, 1 and 2 , were investigated in indomethacin‐induced ulcer models in rats. The gastric lesions were significantly reduced by acetone, hexane, and CHCl3 extracts, with 75.3–41.5% inhibition. Rhizonyl alcohol ( 2 ) significantly reduced the gastric lesions with an inhibition rate of 84.6–42.8%, whereas rhizonaldehyde ( 1 ) significantly increased the gastric lesions. Antioxidant parameters and myeloperoxidase activities were also evaluated in the gastric tissues of the rats. Indomethacin caused oxidative stress, which resulted in lipid peroxidation in gastric tissues by decreasing the levels of the antioxidants as compared to healthy rat tissues. In contrast to indomethacin, all extracts and rhizonyl alcohol ( 2 ) caused a significant decrease in lipid peroxidation levels and an increase in antioxidant parameters, superoxide dismutase, glutathione peroxidase, and glutathione‐S‐transferase, and reduced glutathione in gastric tissues. The administration of rhizonyl alcohol ( 2 ) also resulted in a decrease in gastric myeloperoxidase activity increased by indomethacin. The gastroprotective effect of rhizonyl alcohol ( 2 ) can be attributed to its antioxidant properties and its suppressing effect on neutrophil infiltration into gastric tissues.  相似文献   
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This study was conducted to evaluate the probiotic properties of Pediococcus pentosaceus OZF isolated from human breast milk. The results obtained so far suggest that the strain is resistant to low pH, bile salt, pepsin and pancreatin, so it could survive while passing through the upper part of the gastrointestinal tract and reveal its potential probiotic action on host organism. The strain was non-pathogenic (γ-hemolytic), produced anti-Listerial bacteriocin, exhibited a strong autoaggregating phenotype (85.71%) and demonstrated 6.26 and 12.99% coaggregation with Salmonella enterica serotype Typhimurium SL 1344 and Escherichia coli LMG 3083 (ETEC), respectively. The degree of adhesion of Ped. pentosaceus OZF to the human Caco-2 cell line was investigated and when compared to the adhesion of pathogenic strains tested, it was shown to inhibit the growth of human enterotoxigenic E. coli LMG 3083 (ETEC) and of Salm. Typhimurium SL 1344. Ped. pentosaceus OZF seems to adhere to human intestinal cells via mechanisms that involve different combinations of carbohydrate and lipid factors on the bacteria and eukaryotic cell surface. The percentage of adhesion to n-hexadecane was 34% showing that the surface was rather hydrophilic. Higher affinity displayed by Ped. pentosaceus OZF for chloroform demonstrates the basic property of a cell, which may be due to the presence of carboxylic groups on the cell surface.  相似文献   
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The avian beak is a key evolutionary innovation whose flexibility has permitted birds to diversify into a range of disparate ecological niches. We approached the problem of the mechanism behind this innovation using an approach bridging paleontology, comparative anatomy, and experimental developmental biology. First, we used fossil and extant data to show the beak is distinctive in consisting of fused premaxillae that are geometrically distinct from those of ancestral archosaurs. To elucidate underlying developmental mechanisms, we examined candidate gene expression domains in the embryonic face: the earlier frontonasal ectodermal zone (FEZ) and the later midfacial WNT‐responsive region, in birds and several reptiles. This permitted the identification of an autapomorphic median gene expression region in Aves. To test the mechanism, we used inhibitors of both pathways to replicate in chicken the ancestral amniote expression. Altering the FEZ altered later WNT responsiveness to the ancestral pattern. Skeletal phenotypes from both types of experiments had premaxillae that clustered geometrically with ancestral fossil forms instead of beaked birds. The palatal region was also altered to a more ancestral phenotype. This is consistent with the fossil record and with the tight functional association of avian premaxillae and palate in forming a kinetic beak.  相似文献   
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We investigated the protective effect of caffeic acid phenethyl ester (CAPE) on cyclophosphamide‐induced hemorrhagic cystitis in rats in comparison with 2‐mercaptoethane sulfonate (MESNA). Forty male rats were randomized into four groups: group 1 (control), group 2 (cyclophosphamide), group 3 (cyclophosphamide + MESNA), group 4 (cyclophosphamide + CAPE). Cyclophosphamide injection increased malondialdehyde levels indicating oxidative stress, whereas CAPE and MESNA ameliorated malondialdehyde levels in the bladder (p < 0.05). Only catalase activities were decreased significantly in both groups (cyclophosphamide + MESNA and cyclophosphamide + CAPE, p < 0.05). Pretreatment with CAPE (p < 0.01) resulted in a significant decrease in nitric oxide levels when compared with the cyclophosphamide group. When we consider the studies that show the critical importance of increased nitric oxide levels in pathogenesis of cyclophosphamide‐induced hemorrhagic cystitis, we suggest that it would be more beneficial to use MESNA with CAPE to prevent histological damage.  相似文献   
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During oogenesis, numerous messenger RNAs (mRNAs) are maintained in a translationally silenced state. In eukaryotic cells, various translation inhibition and mRNA degradation mechanisms congregate in cytoplasmic processing bodies (P bodies). The P body protein Dhh1 inhibits translation and promotes decapping-mediated mRNA decay together with Pat1 in yeast, and has been implicated in mRNA storage in metazoan oocytes. Here, we have investigated in Caenorhabditis elegans whether Dhh1 and Pat1 generally function together, and how they influence mRNA sequestration during oogenesis. We show that in somatic tissues, the Dhh1 orthologue (CGH-1) forms Pat1 (patr-1)-dependent P bodies that are involved in mRNA decapping. In contrast, during oogenesis, CGH-1 forms patr-1-independent mRNA storage bodies. CGH-1 then associates with translational regulators and a specific set of maternal mRNAs, and prevents those mRNAs from being degraded. Our results identify somatic and germ cell CGH-1 functions that are distinguished by the involvement of PATR-1, and reveal that during oogenesis, numerous translationally regulated mRNAs are specifically protected by a CGH-1-dependent mechanism.  相似文献   
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