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291.
An investigation was conducted to determine the impact of acute doses of gamma radiation on the microbial community structure of a Holcus lanatus dominated grassland soil. Mesocosms containing soil and established grass were irradiated using a sealed (137)Cs source (7.0 Gy min(-1)). Doses ranged from 5 to 160 Gy, analyses were conducted on the day of irradiation, then 7 and 30 days later. Plant growth and arbuscular mycorrhizal fungal colonisation of roots were reduced by irradiation. Gram-negative bacteria, and microbial metabolic capacity were also negatively affected by treatment. Microbial biomass measured by phospholipid fatty acid (PLFA) analysis, showed an increase at doses above 20 Gy, 7 and 30 days after treatment. Proportions of Gram-positive bacterial and fungal PLFAs fluctuated inversely to each other, in response to both sampling time and radiation dose. We hypothesise that many of the observed soil microbial responses are indirect effects mediated by the influence of ionising radiation on the plants in this system.  相似文献   
292.
In the UK there has been a serious attempt under the current government to foster policy making which is evidence-based and therefore more likely to deliver its intended results. In this article we consider the types of evidence and evidence making that might be required to build effective policy for addressing environmental inequalities. We draw on our experiences of developing an action research approach to policy making in the Environment Agency over a two year period from July 2002 to August 2004. We conclude that an action research approach is well suited to policy making within this new but rapidly growing area of sustainable development policy and urge further exploration of such approaches as a means of better connecting the relevant research, policy making and practitioner communities.  相似文献   
293.
METHOD: A 24-week experiment was conducted to assess how first aid training affects the motivation of small business construction industry employees in avoiding occupational injuries and illnesses and its effect on their occupational health and safety behavior. A simplified multiple baseline design across workplace settings was used to evaluate the effects of first aid training. Participants' motivation to control occupational safety and health risks was explored during in-depth interviews before and after receipt of first aid training. Objective measurement of occupational safety and health behavior was conducted by a researcher directly observing the workplace before and after participants received first aid training. RESULTS: The observations at participants' worksites suggested that, for the most part, the first aid training had a positive effect on the occupational safety and health behavior of participants. First aid training appeared to reduce participants' "self--other" bias, making them more aware that their own experience of occupational safety and health risks is not beyond their control but that their own behavior is an important factor in the avoidance of occupational injury and illness. First aid training also appeared to reduce participants' willingness to accept prevailing levels of occupational safety and health risk and increase the perceived probability that they would suffer a work-related injury or illness. Participants expressed greater concern about taking risks at work after receiving first aid training. IMPACT ON INDUSTRY: It appears that first aid training enhances participants' motivation to avoid occupational injuries and illnesses and improves their risk control behavior. The implications of this are that first aid training can have a positive preventive effect and could complement traditional occupational health and safety training programs. As such, there may be benefit in providing first aid training to all employees rather than limiting this training to a small number of designated "first aiders."  相似文献   
294.
The Context for Substitutes in CVM Studies: Some Empirical Observations   总被引:3,自引:0,他引:3  
The purpose of this paper is to report results from a set of experiments that provide data to test the NOAA [13] Panel recommendation that subjects be reminded of budgetary substitutes when providing values. The results suggest that simply reminding subjects of alternative environmental goods does not affect the distribution of values for a specific good. Such values are affected, however, whenever subjects simultaneously value alternative goods.  相似文献   
295.
Natural factors and human modifications contribute to the estimated annual loss of 10,200 ha of coastal land in the Mississippi River Deltaic Plain Region of south Louisiana. This paper combines information on regional geology and human-induced habitat alterations to evaluate the relative importance of human and natural factors to marsh loss. Data on marsh area and habitat type for 139 7.5-min quadrangles were calculated from maps based on aerial photographs from 1955/56 and 1978, and data on regional geology obtained from published maps were used to construct multivariate model relating initial marsh area, change in urban and agricultural area, change in canal and spoil area, canal area in 1978, depth of sediment overlying the Prairie terrace, and subdelta age to marsh loss. The model indicated that between 25.0% and 39.0% of the marsh loss that occurred during the 23-year period was related to canal and spoil construction, and between 9.5% and 12.7% was related to urban and agricultural development. These are minimal estimates of loss because they do not include many secondary effects (for example, canal orientation, saltwater intrusion, and eutrophication) that can also result in indirect loss. Depth of sediment, initial marsh area, delta lobe age by 1978 canal and spoil area interaction, and indirect effects not included in the model accounted for remaining marsh loss.  相似文献   
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298.
Planning effective strategies to combat air pollution in amajor city such as London requires integration ofinformation on atmospheric concentrations and where theyexceed prescribed air quality standards, detailed data onemissions and potential measures to reduce them includingcosts, and a good understanding of the relativecontributions of different emission sources to pollutantconcentrations plus the remaining background. The UrbanScale Integrated Assessment Model (USIAM) is designed as atool to integrate such information, and to explore andassess a variety of potential strategies for improving airquality. It is based on the same principles as theAbatement Strategies Assessment Model (ASAM) that has beenused in the UN Economic Commission for Europe. To startwith the USIAM model is being developed with respect to theparticulate PM10 only, and in particular the primaryparticulate contribution. The secondary particulate istreated as part of the background superimposed on theprimary particulate concentrations; this may need to betreated more specifically at a later stage, particularlywith respect to nitrate formation over the city. The USIAMmodel therefore sets out to examine a selection of severeepisode conditions as well as long-term annual averageconcentrations, and aims to find strategies that aresuccessful in eliminating exceedance of the prescribedtarget concentrations. By ranking different options forabatement of emissions, for example in terms of cost orease of implementation, the USIAM model can also select andprioritise different potential strategies.  相似文献   
299.
/ This paper reports on the development of abiogeographic-based protected area selection procedure (PASP) that addresseslimitations of current reserve selection methods such as inflexibility,restrictive criteria structures, and disregard of social criteria. We arguethat selection criteria are legitimately identified through the politicalprocess and can therefore have both social and biological content. PASPprovides a systematic, flexible and efficient procedure for identifying anetwork of protected areas that satisfies a given set of selection criteria.PASP has 11 steps divided into three main stages: compilation, selection, andvalidation. A selection algorithm is used into which criteria specific to thebiogeographic region under study can be incorporated. The procedure is ableto accommodate both nominal and ranking criteria and gives the analyst theopportunity to specify thresholds and targets for each criterion. Otherfeatures of PASP include the minimization of data collection effort,consideration of reserve design principles, and inclusion of a networkevaluation as a check to ensure that politically determined objectives havebeen met.KEY WORDS: Land use; Protected area networks; Selection algorithms  相似文献   
300.
Australia is a sparsely populated country that is well endowed with energy resources, and the size of coal, natural gas, and uranium reserves relative to domestic demand has given Australia the opportunity to become a major exporter of these fuels. This paper assesses Australian supply potential of these three fuels, together with crude oil, through to the early years of the next century. With the exception of crude oil, supply potential appears adequate to meet projected domestic and export demand. However, crude oil supplies are unlikely to meet domestic requirements, and to the shortfall may be considerable.  相似文献   
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