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181.
Summary Expatriate consultants are employed in developing countries to perform assessments of the consequences to natural resources and the environment of projects for economic development. Eventually (and as soon as possible) the developing countries must be able to do their own assessments and provide continual guidance to economic planning and management. The presence of foreign experts offers an opportunity to transfer technology and skills during the course of consultancies. A training component can be added with appropriate additional compensation. Some of the barriers to successful training are identified and explored. Careful planning by lenders, host country governments, consultants and trainers will be necessary to realize this potential for building and strengthening indigenous capabilities to wisely exploit and sustain the renewable natural resource base. The following experts from developing countries contributed substantially to this report: W. D. Ailapperuma (Sri Lanka), Herman Haeruman (Indonesia), Noki Makap (Papua New Guinea), Somvonk Poshyananda (Thailand), Suh Junghyun (Korea) and Veronica Villavicencio (Philippines). Richard A. Carpenter M.A., Organic Chemistry, University of Missouri, 1949. Came to EAPI from the National Academy of Sciences/National Research Council where he was executive director of the Commission on Natural Resources. Prior to establishing that office in 1972, was chief of the Environmental Policy Division of the Congressional Research Service, Library of Congress. Has contributed to the passage and implementation of legislation including the National Environmental Policy Act and has been responsible for a variety of studies interpreting and transferring technical information for decision-making. Began his career as a chemist and has obtained patents in the field. John A. Dixon Ph.D., Economics, Harvard University, 1977. B.A., Economics and Oriental Languages (Chinese), University of California at Berkeley, 1968. Previously worked for the Ford Foundation in Indonesia as agriculture programme economist where his main research interests were food policy analysis and natural resource management. At EAPI he is involved with environmental applications of benefit-cost analysis as well as economic aspects of the coal-fuel cycle.  相似文献   
182.
Results of breeding bird censuses in 1979 and 1980 were used to compare the relationships of both species and guilds to forest habitats in the White Mountains of New Hampshire. Several age classes of 11 forest cover types were studied: northern hard-woods (Fagus-Betula-Acer), spruce (Picea), spruce-fir (Picea-Abies), birth (Betula), swamp hardwoods (Acer-Pinus-Tsuga), pine (Pinus strobus andP. resinosa), balsam fir (Abies), aspen (Populus tremuloides andP. grandidentata), northern red oak (Quercus), oak-pine (Quercus-Pinus), and hemlock (Tsuga). All types were even-aged; only northern hardwoods had an additional uneven-aged condition. Forest cover types were also pooled to consider generalized habitats: hardwoods, mixed forest, or softwoods. Results of ordinations based on censuses of 74 bird species indicate that foraging guilds are more related to general cover types than are nesting substrate guilds, but bird species reflect habitat differences to a greater degree than do either guild scheme. Also, considerable overlap occurs in bird species distribution between hardwoods and mixed forests; softwoods show little overlap with other types. Discriminant function and classification analyses revealed that bird species composition can be used to correctly classify general forest habitats more accurately (83.8%) than either foraging (63.2%) or nesting substrate guilds (58.4%). These results indicate that, of the habitats studied, avian species compositions are more characteristic than are foraging or nesting substrate guild composition, which tend to be similar across forest habitats.  相似文献   
183.
From the Editors     

Editorial Introduction

From the Editors  相似文献   
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A variety of novel polymeric materials ranging from elastomers to tough, rigid plastics have been prepared by the cationic copolymerization of regular soybean oil, low-saturation soybean oil, or conjugated low-saturation soybean oil with various alkene commonomers. Using appropriate compositions and reaction conditions, 70–100% of the soybean oil is covalently incorporated into the cross-linked polymer networks, contributing significantly to cross-linking during copolymerization. The resulting thermosets exhibit thermophysical and mechanical properties that are competitive with those of their petroleum-based counterparts. In addition, good damping and shape memory properties have been obtained by controlling the degree of cross-linking and the rigidity of the polymer backbone. New materials with similar characteristics have also been produced from other biological oils, including tung, and fish oils using the same technique. The new, more valuable properties of these bioplastics suggest numerous promising applications of these novel polymeric materials.  相似文献   
186.
ABSTRACT: The number of stream restoration and enhancement projects being implemented is rapidly increasing. At road crossings, a transition must be created from the restored channel through the bridge or culvert opening. Given conflicting design objectives for a naturalized channel and a bridge opening, guidance is needed in the design of the transition. In this paper we describe the use of vanes, cross vanes, and w‐weirs, commonly used in stream restoration and enhancement projects, that may provide an adequate transition at bridges. Laboratory experiments were conducted on vanes and cross vanes to provide a transition for single span bridge abutments and on w‐weirs to provide a transition for double span bridges which have a pier in mid‐channel. The results of the experiments provided design criteria for transitions using each of the three structures. Prior field experience provided guidance on appropriate applications in terms of the stream and bridge characteristics.  相似文献   
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Consideration of biological quality has long been an important component of rating areas for conservation. Often these same areas are highly valued by people for aesthetic reasons, creating demands for housing and recreation that may conflict with protection plans for these habitats. Most methods of selecting land for conservation purposes use biological factors alone. For some land areas, analysis of aesthetic qualities is also important in describing the scenic value of undisturbed land. A method for prioritizing small islands and shoals based on both biological and visual quality factors is presented here. The study included 169 undeveloped islands and shoals ⩽0.8 ha in the Thousand Islands Region of the St. Lawrence River, New York. Criteria such as critical habitat for uncommon plant and animal species were considered together with visual quality and incorporated into a rating system that ranked the islands and shoals according to their priority for conservation management and protection from development. Biological factors were determined based on previous research and a field survey. Visual quality was determined by visual diagnostic criteria developed from public responses to photographs of a sample of islands. Variables such as elevation, soil depth, and type of plant community can be used to classify islands into different categories of visual quality but are unsuccessful in classifying islands into categories of overall biological quality.  相似文献   
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The Miami Conservancy District was organized shortly after the disastrous flood of March 1913 to provide flood protection to municipalities along the Great Miami River. The District system is a classic solution which was entirely locally financed and is now operated and maintained by special benefit assessments on 45,000 parcels of property, 9 cities and 5 counties.  相似文献   
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