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《Conservation biology》1990,4(4):349-349
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Meeting report     
SUMMARY

In many developing countries, the determination of a ranking of investments designed to improve and extend the road system is a commonplace prerequisite of planning for the transport sector as a whole and the road sub-sector within it. A major objective of determining investment priorities is to secure the greatest efficiency in the use of resources allocated to the sector and, for this reason, any system of assigning priorities must rely upon conventional investment appraisal techniques producing quantifiable measures of worth. Exercises of this kind, in which road investments are identified and ranked, are usually undertaken to produce a road sector investment plan. The implementation of such plans is, however, often compromised because of perceived deficiencies with a methodology which places undue reliance on investment appraisal and fails to properly address the issue of public interest and sustainability. This paper attempts to produce a pragmatic set of ground rules which, while mindful of the need to promote economic efficiency, allow for other factors to be embraced in a more holistic methodology.  相似文献   

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Meeting Report     
《Conservation biology》1987,1(3):186-187
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降水与气温之间的不同关系类型对植被、水资源、生态环境等有着不同的影响,全面揭示大范围多气候类型区关系类型及其时空变异性和影响成为重要研究内容.文章以范围较广、涵盖气候类型较多的中国北方地区为研究区,利用研究区及其周边的357个高密度气象站点1951—2016年年降水量、气温数据,采用中心聚类等方法,定性、定量揭示了中国...  相似文献   

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E. Yoshioka 《Marine Biology》1987,96(3):371-374
Annual reproductive cycle of the chiton Acanthopleura japonica (Lischke) was studied by observing both gonad index and histological features from October 1980 to October 1981. No significant changes in each factor were observed from October to April. Increased values of gonad index and spermatogenesis or vitellogenesis in gondas were observed from May to September. In the same time, gonad index decreased and sperms or oocytes in gonalds disappeared in the days around spring tide, and they were recovered around neap tide. Suggested spawning around spring tide from May to September is also supported by the occurrence of released eggs in the days around the new and full moons.  相似文献   

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Minamata disease: A 1989 update on the mercury poisoning epidemic in Japan   总被引:2,自引:0,他引:2  
Minamata disease first became evident in Japan in 1956 and was caused by methyl mercury exposure. Over 20,000 people are now thought to have been affected. This article compares the situation immediately following the initial discovery with that now prevalent.The author, then a final year medical student, spent her elective period (a nine week study period) in the area in the summer of 1989. This paper is based on that experience and is published in order to provide an update on a classic pollution episode which was widely publicised in the years immediately after its discovery but about which less has been heard in recent years.  相似文献   

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