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21.
The quality of the waters collected from R. Arno was examined in the period September 1988 to December 1989. A first campaign in September/October 1988, during a period of low water, gives a general picture of pollution conditions along the river from the source to the mouth. the river appears to be heavily polluted immediately downstream of Florence and in the area of the textile industry.

In the second campaign, through the whole year 1989, particular attention has been given to the Florence area; the most significant results, compared with those from a previous investigation carried out in 1971, show only a small reduction of the pollution load, due to the shortage and inadequacy of wastewater depuration. Some considerations are reported on pollution drop with full spate.  相似文献   
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Bocchetti R  Regoli F 《Chemosphere》2006,65(6):913-921
The Mediterranean mussel, Mytilus galloprovincialis, is a classical sentinel organism for monitoring the biological effects of contaminants through the use of molecular and cellular biomarkers. These biological responses can be modulated also by seasonal changes of both environmental and biological factors, potentially influencing responsiveness and sensitivity to pollutants. The aim of this study was to characterize in a reference mussel population from the Adriatic Sea, the natural fluctuations of several oxidative stress biomarkers widely used in ecotoxicological applications. Analyses of individual antioxidant defenses (catalase, glutathione S-transferases, glutathione reductase, glutathione peroxidases, levels of glutathione) were integrated with those of the total oxyradical scavenging capacity (TOSC-assay), which quantify the overall capability of a tissue to neutralize different forms of oxyradicals. Due to the close relationship between antioxidant efficiency and onset of various cellular alteration, the seasonal characterization was carried out also on lysosomal membrane stability, accumulation of malondialdehyde, neutral lipids and lipofuscin, levels of metallothioneins and activity of peroxisomal enzymes (acyl-CoA oxidase and d-aminoacid oxidase). Results indicated a significant seasonality for several biological responses; major variations occurred especially in spring and summer months suggesting the influence of natural factors, such as temperature, reproductive cycle and food availability. The observed seasonal oscillations revealed both similarities and differences with those reported for other Mediterranean mussel populations suggesting that opposite trends can occur when the same environmental prooxidant factors have a different regional influence.  相似文献   
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Environmental Geochemistry and Health - Thermal caves represent an environment characterized by unique chemical/physical properties, often used for treatment and care of musculoskeletal,...  相似文献   
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This research examines the potential downsides of divestiture socialization. We theorize that supervisor behaviors and attitudes—that is, support for authenticity and creativity expectations—moderate the different stages of a model in which newcomers' authentic self‐expression mediates the negative effect of divestiture socialization on newcomer task performance, creativity, social integration, and job satisfaction. Specifically, supervisor support for authenticity allows newcomers to express their authentic self when faced with divestiture processes, and perceived supervisor creativity expectations enable them to deploy their authentic self‐expressions to enhance their creativity. A time‐lagged, multisource study of 142 newcomer—supervisor dyads provides support for these predictions, offering notable implications for theory and practice.  相似文献   
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Landscape-level thresholds, and newt conservation.   总被引:4,自引:0,他引:4  
Ecological thresholds are defined as points or zones at which a rapid change occurs from one ecological condition to another. The existence of thresholds in species-habitat relationships has important implications for management, but the lack of concordance across studies and the wide range of methods used make generalizations difficult. We used two different statistical methods to test for the existence of thresholds for both individual species and the whole community, using three newt species as models. Based on a sample of 371 ponds, we found significant thresholds for both landscape configuration and composition. These were for the relationships between distance to forest and occurrence of Triturus alpestris and T. helveticus, and forest and crop cover and T. helveticus. Variability in the location of thresholds observed for the different species in this study caution against their use at the community level. Future studies should be based on the identification and assessment of thresholds for targeted species. Thresholds can be a useful concept from which tools may be developed to focus conservation effort for threatened species and their habitats.  相似文献   
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Chiral, atropisomeric 2,2'-dihydroxy-1,1'-binaphthyl has been extensively used to direct asymmetric processes. Its key role in asymmetric catalysis has spurred efforts to synthesize it in the optically pure form, but the reported synthetic routes have a significant environmental impact. In an aqueous peroxydase-cyclodextrin system the oxidative coupling of 2-naphthol took place very rapidly in almost quantitative yield and resulted in an enantiomeric excess. This one-pot synthesis do not require any organic solvents and oxidising metal cations.  相似文献   
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