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81.
Collecting marine organisms for the discovery and development of pharmaceuticals has been perceived variously as sustaining and threatening conservation. Our initial expectations that marine bioprospecting might pose conservation challenges were largely not confirmed. Thousands of marine species have been collected for initial assessment, but usually only in very small amounts. Very few compounds are sufficiently promising to provoke re-collections, where volumes can be much larger. This is where conservation concerns may arise, particularly if the organism is rare, has a restricted distribution, or is targeted in one narrow area. However, industry generally seeks to avoid dependency on small populations, for economic as well as ecological reasons. Alternative supply strategies to wild capture include synthesis and culture. Mandatory collection protocols and environmental impact (stock) assessments are useful routes for management to achieve sustainable use where extraction is desirable. In general, the scanty information available suggests that marine bioprospecting for pharmaceuticals may have minimal impacts on the environment, particularly compared with those created by other pressures. 相似文献
82.
In-vessel composting of an aged coal-tar contaminated soil from a manufactured gas plant site was investigated over 98days using laboratory-scale in-vessel composting reactors. The composting reactors were operated at 18 different operational conditions using a logistic three-factor factorial design with three temperatures (T=38, 55 and 70 degrees C), four soil to green waste ratios (S:GW; 0.6:1, 0.7:1, 0.8:1 and 0.9:1 on a dry weight basis) and three moisture contents (MC; 40%, 60% and 80%). Excitation-emission matrix (EEM) fluorescence spectroscopy was used to investigate organic matter dynamics in the composting mixture. The results of this investigation indicated that formation of humic substances can be monitored by fluorescence excitation-emission matrix, and provided evidence of progressive mineralization or humification of the composting mixture. Peak excitation wavelength shifts and peak fluorescence intensity can both be used as indicators to monitor the humification or maturation of compost. Finally, the fluorescence index can be applied to investigate the origin of humic substances and fulvic acids, and the humification or maturation of compost. 相似文献
83.
Creg S. Bishop Glen T. Broach Wendell H. Hester Vincent A. Sikora 《Journal of the American Water Resources Association》1982,18(2):189-195
ABSTRACT: The importance of water conservation was emphasized by a proposed National Water Policy which was established during the previous Carter Administration. This policy stressed water conservation on a national scale. Such a policy sought to apply one program to all water resources problems. Before implementation of this or another such policy, consideration must be given to those vast areas of the country which in reality do not have a shortage of water. One of these areas is the French-Broad River basin in Tennessee. This report was formulated in an effort to describe both the positive and negative effects of water policies which would bring about either a 10 percent or 30 percent reduction in water usage in this basically water rich area. The parameters used in the evaluation included selected economic, sociological, legal, and environmental impacts. 相似文献
84.
VanWieringen LM Harrison JH Nennich T Davidson DL Morgan L Chen S Bueler M Hoisington F 《Journal of environmental quality》2005,34(1):164-173
Legislation in the United States has recently focused on improving water quality by establishing management practices that limit the quantities of nutrients entering the water supply. Timely application and quantification of the amount of manure applied throughout the grass-growing season can reduce the loss of nutrients into ground or surface water while improving the quality and quantity of grass harvested. During the 2001 and 2002 growing seasons, we measured the effects of different manure application rates on grass yields, grass nutritive value, and soil chemistry on a dairy farm. On-farm estimates of manure N were combined with yield estimates and forage quality measures to evaluate the effects of varying levels of manure application. Yield estimates, N content of grass, and the amount of N in soil and manure were monitored at each cutting for plots amended at different manure application rates. There are three major outcomes of this evaluation: (i) new grass seedings were at higher risk of elevated levels of nitrate N in forage; (ii) increased forage nitrate N at harvest was associated with malfermented silage and increased levels of ammonia N, which resulted in less efficient use of metabolizable protein for milk production; and (iii) increased understanding of N cycling between manure, soil, and plant provided an opportunity to reduce purchased fertilizer. 相似文献
85.
86.
Mrs Sue Hare is the education and information services coordinator of the UK Atmospheric Research and Information Centre (ARIC). Professor James Longhurst was recently the director of the ARIC and Joe Buchdahl its global climate change information services coordinator. Professor Longhurst is now head of the Department of Environmental Health and Science, University of the West of England, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY. Kelvin Williams is a geography consultant and is head of geography at Ysgol y Creuddyn, Penrhyn Bay, Llandudno, Gwynedd LL30 3LB. The pedagogy of atmospheric issues is identified in the context of environmental education in this paper. The UK Atmospheric Research and Information Centre (ARIC) has developed an education programme which has responded to the dynamic issues relating to the atmosphere since the establishment of the ARIC in 1984. The main route for the teaching of atmospheric issues is identified as being through the UK's National Curriculum although public awareness of issues has increased through the media and more recently through government publicity campaigns. 相似文献
87.
Paul Polak Bob Nanes Deepak Adhikari 《Journal of the American Water Resources Association》1997,33(1):119-124
ABSTRACT: In areas where water is scarce, drip irrigation provides the most efficient way to conserve irrigation water, but its cost of £1000 an acre is prohibitive for most small farmers in developing countries. The cost was reduced by 90 percent by (1) making dripper lines moveable, so that each line reaches ten rows instead of one; (2) replacing 25-cent emitters with simple 0.70 mm holes punched by a heated needle; and (3) using £3.00 off-the-shelf 20 liter containers with cloth filters in place of expensive filter systems. This reduced the cost of a half-acre system to £50. The low cost system was field tested in the hill areas of Nepal, and in mulberry cultivation in Andhra Pradesh, India. Uniformity of flow from emitters was 73–84 percent. Small farmers reported that the low cost trickle irrigation system cut labor requirements in half, and doubled the area irrigated by the same amount of water. The low cost drip system is likely to be widely adopted by small farmers in semi-arid and hilly regions. 相似文献
88.
89.
90.
An Aquifer Vulnerability Assessment of the Paluxy Aquifer, Central Texas, USA, Using GIS and a Modified DRASTIC Approach 总被引:9,自引:1,他引:8
D epth to water, net Recharge, Aquifer media, Soil media,
Topography, Impact of the vadose zone, and
Conductivity of the aquifer). Using such an approach allows one to investigate the potential for groundwater contamination
on a regional, rather than site-specific, scale. Based upon data from variables such as soil permeability, depth to water,
aquifer hydraulic conductivity, and topography, subjective numerical weightings have been assigned according to the variable's
relative importance in regional groundwater quality. The weights for each variable comprise a GIS map layer. These map layers
are combined to formulate the final groundwater pollution potential map. Using this method of investigation, the pollution
potential map for the study area classifies 47% of the area as having low pollution potential, 26% as having moderate pollution
potential, 22% as having high pollution potential, and 5% as having very high pollution potential. 相似文献