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991.
Abstract: Limited information exists on pesticide use for nonagricultural purposes, making it difficult to estimate pesticide loadings from nonagricultural sources to surface water and to conduct environmental risk assessments. A method was developed to estimate the amount of pesticide use on recreational turf grasses, specifically golf course turf grasses, for watersheds located throughout the conterminous United States (U.S.). The approach estimates pesticide use: (1) based on the area of recreational turf grasses (used as a surrogate for turf associated with golf courses) within the watershed, which was derived from maps of land cover, and (2) from data on the location and average treatable area of golf courses. The area of golf course turf grasses determined from these two methods was used to calculate the percentage of each watershed planted in golf course turf grass (percent crop area, or PCA). Turf‐grass PCAs derived from the two methods were used with recommended application rates provided on pesticide labels to estimate total pesticide use on recreational turf within 1,606 watersheds associated with surface‐water sources of drinking water. These pesticide use estimates made from label rates and PCAs were compared to use estimates from industry sales data on the amount of each pesticide sold for use within the watershed. The PCAs derived from the land‐cover data had an average value of 0.4% of a watershed with minimum of 0.01% and a maximum of 9.8%, whereas the PCA values that are based on the number of golf courses in a watershed had an average of 0.3% of a watershed with a minimum of <0.01% and a maximum of 14.2%. Both the land‐cover method and the number of golf courses method produced similar PCA distributions, suggesting that either technique may be used to provide a PCA estimate for recreational turf. The average and maximum PCAs generally correlated to watershed size, with the highest PCAs estimated for small watersheds. Using watershed specific PCAs, combined with label rates, resulted in greater than two orders of magnitude over‐estimation of the pesticide use compared to estimates from sales data.  相似文献   
992.
In the early years after World War II the developed countries, and in particular the USA, acounted for a large portion of world metal consumption. Since that time a shift in consumption has occurred favouring the industrialized states of Western Europe, the centrally planned economies of Eastern Europe, and more recently Japan and the other Pacific Rim countries of Asia (PRA). After assessing the magnitude of the shift in metal consumption toward the PRA countries, this paper focuses on differences in economic growth, the nature of trade, and other factors responsible. Finally, the implications of the shift are considered for the nature of metal trade, the competitiveness of metal exporting countries, the structure of international metal markets, and the future availability of metal supplies.  相似文献   
993.
994.
The important role that non-motorised transport plays in urban sustainability is discussed with particular reference to the developing world and to the links between environmental and poverty issues. The significance of non-motorised transport in terms of reduced pollution, income maintenance for the poor and providing transport for vulnerable groups is stressed and placed within the general context of sustainable development. More specifically, evidence is presented for rickshaws in Calcutta, which demonstrates the vital role that non-motorised transport must play if sustainable development objectives are to be met. This evidence indicates that if rickshaws were to disappear from Calcutta's streets there would not only be significant increases in air pollution but also a substantial increase in the numbers of people living in poverty.  相似文献   
995.
996.
997.
Lets' save Mono Lake   总被引:1,自引:1,他引:0  
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998.
The present study attempted to assess the extent to which job incumbents engage in performance relevant self-regulatory activities. Specifically, the degrees to which 62 insurance salespersons; (1) set performance goals, (2) monitored performance levels, and (3) exercised contingent self-reward or punishment with respect to goal achievement or goal failure were measured; and, the consequences that such activities had on performance were examined. The results of this study indicate that, in general, subjects set goals, but typically of a distal/result-orientated, as opposed to a proximal/behaviourally orientated-nature. Goal setting per se had no effects on sales performance, although an objective measure of goal difficulty was related to this criterion. With respect to self-monitoring, it was discovered that the greatest amount of performance feedback came from oneself and one's supervisor, as opposed to one's co-workers. In terms of performance, there was an interaction of feedback source and feedback preference such that the ability to generate internal feedback was related to performance only for individuals who had a preference for such internal feedback. There appeared to be no substantial amount of contingent self-reward occurring within this organization, although contingent self-punishment (in the form of self-criticism) was in evidence; and, such self-admonishment seemed to have detrimental effects on performance. While the three classes of variables independently explained 26 per cent of the variance in performance, the interactive effects suggested by theories of self-regulation (Bandura, 1977; Kanfer, 1971) were not in evidence.  相似文献   
999.
1000.
The spatial and temporal variability of transparency measured for 15 years at 7 stations near the San Diego sewage outfall has been investigated and compared to the temporal variability of sewage suspended solid discharge and flow rate. the purpose of the time-series analyses was to distinguish natural from human (sewage discharge) causes of temporal changes in transparency. the results show that: 1) variations in transparency are highly correlated over the entire area, but there is a gradient in means and variability in the direction perpendicular to the coast; 2) there are no long term trends for increase or decrease in the water clarity at any of the stations; 3) most of the variance of transparency is contained in the seasonal frequency band; 4) over the same time period sewage discharge has significantly increased and suspended solids decreased; 5) most of the variance of these human-caused properties is in the interannual frequency band; (6) there is no correlation at any time-lag between water clarity and suspended solid discharge or flow. These results lead to the conclusion that these anthropogenic properties are not affecting transparency, while natural factors such as seasonality and distance from coast do.  相似文献   
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