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71.
Recent studies point to the need for improved understanding of environmental management frameworks designed to combine qualitative public and quantitative technical inputs in decision-making processes. Flux in public perception and concern about risks imply frameworks must be iterative in nature and incorporate a variety of assessment triggers in the form of decision points. A conceptual model is proposed here to explain the de facto operation of standard risk analytic frameworks within the broader sociopolitical milieu of public policy. The model is presented as a decision flow diagram that emphasizes setting environmental management goals based on societal input and the formulation of decision criteria for selecting management actions to achieve those goals. Prospective and retrospective decision control points operate to select management options that, respectively, avoid or reduce actual or predicted effects. Feedback loops that modify risk management outcomes are identified. Technical and scientific inputs (i.e., risk analysis) are assigned an essential information role within the framework and are responsible for informing the management process with the results of appropriately conducted and reviewed investigations. The proposed model is intended primarily to indicate how environmental risk management decision-making and associated technical assessments may be influenced by social pressures. It is hoped this understanding will lead to analytical transparency and better public communication of the environmental implications of policy options.  相似文献   
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Hydrobiologia - Understanding the concordance between aquatic assemblages in ecological assessments and their responses to human-induced disturbances are fundamental steps toward achieving...  相似文献   
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Hereditary degeneration of photoreceptors has been linked to over-activation of Ca2+-permeable channels, excessive Ca2+-influx, and downstream activation of Ca2+-dependent calpain-type proteases. Unfortunately, after more than 20 years of pertinent research, unequivocal evidence proving significant and reproducible photoreceptor protection with Ca2+-channel blockers is still lacking. Here, we show that both D- and L-cis enantiomers of the anti-hypertensive drug diltiazem were very effective at blocking photoreceptor Ca2+-influx, most probably by blocking the pore of Ca2+-permeable channels. Yet, unexpectedly, this block neither reduced the activity of calpain-type proteases, nor did it result in photoreceptor protection. Remarkably, application of the L-cis enantiomer of diltiazem even led to a strong increase in photoreceptor cell death. These findings shed doubt on the previously proposed links between Ca2+ and retinal degeneration and are highly relevant for future therapy development as they may serve to refocus research efforts towards alternative, Ca2+-independent degenerative mechanisms.Subject terms: Cell death in the nervous system, Ion channels in the nervous system, Molecular neuroscience  相似文献   
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This paper reviews the current status of nematodes with stress-inducible transgenes as biosensors responsive to a range of external stressors, e.g., soil or water pollution, microwave radiation or immunological attack. TransgenicCaenorhabditis elegans carrying reporter genes under heat shock promoter control express reporter products only under stressful conditions. Although relatively insensitive to single metal ions, these worms respond to complex mixtures present in metal-contaminated watercourses and to laboratory mixtures containing similar constituents, but not to any of their components singly at comparable concentrations. Responses to metal mixtures are enhanced by a non-ionic surfactant, Pluronic F-127. Metals taken up by food bacteria and insoluble metal carbonates can also evoke stress responses, both in soil and aqueous media. However, high concentrations of added metals are needed to induce clear-cut responses in soil, owing to metal sorption onto clays and organic matter. Transgenic worms are also stressed by exposure to microwave radiation; pulsed signals generate responses that diminish markedly with distance from the source. Finally, stress responses are inducible by anti-epicuticle antisera and complement, suggesting that immune attack can also activite the heat shock system. The development of rapid microplate toxicity assays based on transgenic nematodes is discussed.  相似文献   
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OBJECTIVE: To investigate explanations for social inequalities in health with respect to health related social mobility and cumulative socioeconomic circumstances over the first three decades of life. DESIGN: Longitudinal follow up. SETTING: Great Britain. SUBJECTS: Data from the 1958 birth cohort study (all children born in England, Wales, and Scotland during 3-9 March 1958) were used, from the original birth survey and from sweeps at 16, 23, and 33 years. MAIN OUTCOME MEASURES: Subjects'' own ratings of their health; social differences in self rated health at age 33. RESULTS: Social mobility varied by health status, with those reporting poor health at age 23 having higher odds of downward mobility than of staying in same social class. Men with poor health were also less likely to be upwardly mobile. Prevalence of poor health at age 33 increased with decreasing social class: from 8.5% in classes I and II to 17.7% in classes IV and V among men, and from 9.4% to 18.8% among women. These social differences remained significant after adjustment for effects of social mobility. Health inequalities attenuated when adjusted for social class at birth, at age 16, or at 23 or for self rated health at age 23. When adjusted for all these variables simultaneously, social differences in self rated health at age 33 were substantially reduced and no longer significant. CONCLUSIONS: Lifetime socioeconomic circumstances accounted for inequalities in self reported health at age 33, while social mobility did not have a major effect on health inequalities.  相似文献   
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