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361.
Christopher Raymond 《Journal of Environmental Planning and Management》2006,49(6):797-812
Traditional park and reserve selection techniques that rely exclusively on expert assessment can marginalize local knowledge and values in the review process. Using survey data from the Otways region of Victoria, Australia, we present a method that differentiates between public and private lands using locally perceived landscape values. The results are used to assess prospective national park expansion areas. Two data models of mapped landscape values—vector and raster—were analysed using discriminant analysis to classify and predict land status. Results indicate survey respondents hold more indirect and less tangible values for national parks and reserves, and more direct use values for private lands. There was moderate agreement between public and expert-derived national park boundaries. The mapping of local landscape values appears useful in planning and reviewing public land classifications, and when combined with biological assessments, can strengthen protected areas planning and management in Australia and elsewhere. 相似文献
362.
James B. Shanley Pavel Krám Jakub Hruška Thomas D. Bullen 《Water, Air, & Soil Pollution: Focus》2004,4(2-3):325-342
Much of the biogeochemical cycling research in catchments in the past 25 years has been driven by acid deposition research funding. This research has focused on vulnerable base-poor systems; catchments on alkaline lithologies have received little attention. In regions of high acid loadings, however, even well-buffered catchments are susceptible to forest decline and episodes of low alkalinity in streamwater. As part of a collaboration between the Czech and U.S. Geological Surveys, we compared biogeochemical patterns in two well-studied, well-buffered catchments: Pluhuv Bor in the western Czech Republic, which has received high loading of atmospheric acidity, and Sleepers River Research Watershed in Vermont, U.S.A., where acid loading has been considerably less. Despite differences in lithology, wetness, forest type, and glacial history, the catchments displayed similar patterns of solute concentrations and flow. At both catchments, base cation and alkalinity diluted with increasing flow, whereas nitrate and dissolved organic carbon increased with increasing flow. Sulfate diluted with increasing flow at Sleepers River, while at Pluhuv Bor the sulfate-flow relation shifted from positive to negative as atmospheric sulfur (S) loadings decreased and soil S pools were depleted during the 1990s. At high flow, alkalinity decreased to near 100 μeq L-1 at Pluhuv Bor compared to 400 μeq L-1 at Sleepers River. Despite the large amounts of S flushed from Pluhuv Bor soils, these alkalinity declines were caused solely by dilution, which was greater at Pluhuv Bor relative to Sleepers River due to greater contributions from shallow flow paths at high flow. Although the historical high S loading at Pluhuv Bor has caused soil acidification and possible forest damage, it has had little effect on the acid/base status of streamwater in this well-buffered catchment. 相似文献
363.
Raymond F. Mikesell 《Resources Policy》1978,4(3):194-199
Recent agreements between host country governments and foreign investors in the resource industries reflect an effort to meet the objectives of both parties. In some cases majority government ownership is combined with management control and the right of veto on certain policy questions by the foreign investor. Imaginative tax formulas are built into agreements that combine the principle of excess profits taxes with that of a minimum DCF rate of return. Expropriation risk is being limited by employing a high debt-equity ratio. Foreign investors are agreeing to programmes and policies that promote host country economic and social development, while host country governments are quaranteeing foreign investors against changes in laws that would affect their profits. 相似文献
364.
Raymond Herrmann 《Journal of the American Water Resources Association》1976,12(2):371-380
ABSTRACT. The occurrence of ground water in the lower North Platte Valley, Goshen County, Wyoming, was studied to determine safe yield within the alluvial aquifer under varying discharge and recharge conditions. The alluvium of the North Platte is extensively developed for irrigation purposes and the effects of large-scale pumpage are of major concern. Actual withdrawals are estimated to be 46,000 acre-feet. Should pumping reach potentially higher levels an overdraft is expected. Effect of ground water withdrawals are established from projections of the flow regime within the alluvial aquifer. A time dependent, numerical model was employed to predict aquifer response to increased withdrawals. The results suggest that more efficient use of surface waters and/or increased use of ground water will reduce the annual subsurface return flow to the North Platte River and its tributaries by an amount equal to the reduced ground water recharge increment. Alternatives are available for management of the lower North Platte alluvial aquifer. The preferred course is to correlate surface and subsurface water rights, in light of convenience, economics, and best means of storage for maximum utilization of the single water resource. 相似文献
365.
Raymond L. Nace 《Journal of the American Water Resources Association》1974,10(4):633-647
ABSTRACT: Pierre Perrault, member of a bourgeois provincial family whose roots were in the Touraine region of France, grew up in Paris. One of six illustrious brothers, all characterized by brilliance and diversity, he was educated as a lawyer but turned to finance and rose to a high position under King Louis XIV. Owing to political naivete and financial imprudence, he fell into disgrace and went bankrupt. He then became an amateur scientist and wrote a book on the origin of springs. This book broke almost wholly with the traditional authoritarianism of 2, 000 years'standing, and set hydrology on the modern path of observation and direct experiment, He developed the concept of the hydrological cycle, correctly accounting for the disposition of rainfall by evaporation, transpiration, ground-water recharge and runoff. Some of his ideas about specific processes were erroneous, but where he was wrong his errors were logically based. Much of his contribution to the foundation of scientific hydrology has been overlooked or distorted by historians and hydrologists alike. 相似文献
366.
Sandra L. S. Hatcher Que Trang Lambert Raymond L. Teplitz James R. Carlson 《黑龙江环境通报》1993,13(3):171-177
The formation of heteroduplexes from polymerase chain reaction (PCR) products has recently become a diagnostic tool that is routinely used for the prenatal detection of small deletions or insertions in a number of disease-causing alleles. We present evidence illustrating that heterozygous PCR products can manifest ‘invisible’ heteroduplexes that can ultimately lead to genotyping errors. Justifications for these ‘invisible’ heteroduplexes and requisite parameters to optimize their detection are presented. 相似文献
367.
A child was tentatively diagnosed as having cystic fibrosis, based on neonatal presentation with severe gastrointestinal complications; the diagnosis was not confirmed biochemically and no tissues were available for DNA analysis. The mother presented in her subsequent pregnancy, and microvillar enzyme analysis of cell-free amniotic fluid at both 18 and 20 weeks gestation gave equivocal results. The pregnancy was terminated voluntarily because of a trend towards abnormal enzyme assay results on the second amniocentesis. Retrospectively, fetal tissues were found to be homozygous for the most common mutation of the cystic fibrosis gene (AF508), which confirmed the prenatal assessment and suggested that the first infant of the couple was probably also affected by the disease. 相似文献
368.
Economics: Theory versus Practice in Wildlife Management 总被引:1,自引:0,他引:1
One of the most controversial issues in wildlife management in North America is the trend towards the commercialization of wildlife. The sale of hunting privileges and game ranching are forms of wildlife commercialization that have not been unanimously accepted, and widely opposing views exist on the merits and drawbacks of the use of economic incentives for the management of wild animals. In this essay the use of economics is explored from a theoretical "free market" perspective and from a more practical point of view. The issue of market failure is addressed and potential solutions are offered, such as tax incentives and government farm programs. Also the question of when market-oriented solutions are applicable to wildlife is discussed. We conclude that polarization of the issue is counterproductive and that some of the more innovative solutions to current wildlife management problems can be found between the opposite extremes of public ownership and the profit-motivated incentives offered by the market. 相似文献
369.
Summary The distribution of the spider Zygiella x-notata was examined using field populations of adult females occupying the outside frames of windows. The structure of the populations was aggregative, and the distribution of individuals on the window frames and the size of the webs were density dependent. Also, the sizes of the webs of neighbouring spiders on the same window alternated. This spatial organization involves interactions between neighbours. If one spider out of two is removed, and if all the webs are destroyed, remaining spiders that previously had small webs significantly increase the size of their construction. In contrast, individuals that previously had large webs do not modify the size of their construction. This shows that individuals of Z. x-notata respond to the presence of neighbours. The influence of intraspecific interactions in such a population is discussed. 相似文献
370.
Raymond Prince 《Journal of Environmental Economics and Management》1985,12(2):179-180
The sign of the adjustment to the riskless discount rate for environmental risk depends on whether the price of avoiding the consequences of the externality is seen as reducing expected net benefits or increasing expected costs. The conclusion is that the risk adjustment is positive when the externality is defined as reducing expected net benefits. 相似文献