The fate of 15N-labeled cattle (Bos taurus) urine (52 g N m(-2)), applied to a 0.4-m2 surface area on three dates between May and October to three different pasture soils, was studied using 2-m2 lysimeters. Over a period of two years, the sward recovered most of the 15N, but the amount recovered decreased with application date (62% in spring to 17% in fall). However, N uptake by ryegrass (Lolium perenne L.) in Year 2 showed that some nitrogen came from the previous year's urine application. The largest leaching losses of urine N resulted from the late application date. These losses mainly occurred during the first winter despite the small amount of water drainage. Soil type largely determined 15N losses. The granitic Brunisol was the most freely draining and had the greatest leaching (up to 35% recovery of urinary N). In contrast, leaching in the silty loam Neoluvisol remained under 4% of 15N applied. The Calcosol appeared to be susceptible to all kinds of N losses with intermediate unaccounted-for N pool and leaching fractions and lesser utilization of urinary N by grass. Immobilization in soil organic matter, roots and litter, and stubble pools were not markedly influenced by the date of application or soil type. They amounted to 25 to 33, 2, and 2% of N applied as urine, respectively. In these climatic conditions with moderate drainage, leaching of water poor in quality for nitrate only occurred for late-season grazing or on the granitic Brunisol, which was very vulnerable to leaching. 相似文献
The prediction of the probability of death or injury following the inhalation of a toxic gas or vapour is used in risk analysis. The proportion of a population responding for a given endpoint (e.g. lethality) can be related to the received dose using a probit model. Some of the coefficients in the probit equations are based on data from animal testing. Generally, experimental test animals are bred to exhibit low variability. Animal variability in response to toxic exposures may not adequately represent human variability in response to toxic exposures to the tested chemical. It is suggested that some independently established measure of human variability be used in the formulation of the probit equation constants rather than those that arise solely from the fitting of the animal data. 相似文献
In selecting six keywords from the environmental discourse the authors argue that language's 'double motivation' reveals a dialectical structure through which it simultaneously expresses both a utopian narrative and an ideologically driven myth of totality and consensus. The ambiguity of these keywords is of critical significance to all those involved in the environmental discourse, for without agreement on the meaning of commonly used concepts effective policy development is potentially disabled. The keywords we explore are 'community', 'sustainability', 'globalisation', 'diversity', 'democracy' and 'environment' itself. 相似文献
ABSTRACT: During recent years many countries have moved to rationalize the management of state owned or state controlled resources. In Victoria, Australia, water, in particular, has received a great deal of attention. Subsidies to construct, operate, and rehabilitate irrigation facilities have been reduced, and there have been numerous consolidations of small water supply authorities to achieve economies of scale. In addition, Victoria has taken the unusual step of using auctions to allocate new irrigation water entitlements. The six water auctions that took place during 1988 and early 1989 were perceived as an efficient and equitable mechanism to allocate limited water supplies to their highest value use. While the agricultural areas where the different auctions occurred were similar, there was substantial variation in the prices paid, which reflects varying demands for additional irrigation water. This paper will discuss the following topics: the auction process used and the results of the auctions, the efficiency of the auction procedures, and the factors influencing the demand for additional irrigation water in the different auctions. In addition, the implications of using auctions to allocate water supplies for future water management in Victoria will be discussed. 相似文献
Differences exist in the spatial structure of cities in both the developed and developing world owing to the contradistinctive nature of their urban growth processes. The structure of Nigerian cities is characterised by the preponderance of mixed land uses resulting primarily due to the organic nature of city growth and more fundamentally, owing to the dynamics of informal urban economic activities. This paper examines mixed land‐use patterns in selected Nigerian cities and appraises their relevance in the general city growth process. By suggesting principles and speculative spatial patterns expressing desirable use combinations, an attempt is made to rationalise the utility of the concept such that its environmental impact is understood and given planning resolution. 相似文献
In March 1994, China announced its plans for sustainable development in a White Paper entitled 'China's Strategy for Population, Environment and Development in the 21st Century. To achieve the objective of sustainable development; economic, social and environmental aims have to be consistent with each other and meet the needs of the present, without compromising the ability of future generations to meet their own needs. Sustainable development, therefore, encompasses many 'ideals, which need to be introduced through practical management techniques. This paper addresses the role that EIA could play in promoting sustainable development projects in the People's Republic of China by way of the detailed examination of a case study—the Shanghai Second Sewerage Project. 相似文献
Ecological Politics in an Age of Risk. Ulrich Beck, translated by Amos Weisz, 1995 Cambridge, Polity Press, first published Germany 1988. ISBN 0 7456 077632, hb £39.50; ISBN 0 7456 13772, pk £12.95
Environmentally Sustainable Business: a local and regional perspective. Peter Roberts, 1995, London, Paul Chapman. ISBN 1 85396 240 6, price not given
Methods of Environmental Impact Assessment. Peter Morris & Riki Therivel (Eds) 1995, London, UCL Press, 378 pp. ISBN 1 85728 117 9, hb £45.00; 1 85728 118 7, pb £14.95
A Guide to Local Environmental Auditing. Hugh Barton & Noel Bruder, 1995, London, Earthscan, 370 pp. ISBN 1 85 383 2340, pb £18.95
Household Waste Recycling. Richard Waite, 1995, London, Earthscan, ISBN 1 8538 3 2421, hb £29.95
A Seed in Time: Proceedings of the 3rd International Conference on Urban and Community Forestry. Forestry Commission, 1994. ISBN 0 885 38 328 3, £9.50 inc p&p (Copies available from: Marcus Sangster, Forestry Commission, 231 Corstorphine Road, Edinburgh EH12 7AT)
Environmental Policy in New Zealand: the politics of clean and green? Tom Buhrs & Robert Bartlett, 1993, Auckland, Oxford University Press viii + 192 pp.
Green Politics. Stephen Rainbow, 1993, Auckland, Oxford University Press xv + 106 pp.
The Future of Community Lands: human resources. E. Ndione, P. DeLeener, M. Ndiaye, P. Jacolin & J.-P. Perier, 1995, London, Intermediate Technology, 236 pp. ISBN 1 339 2480, £14.95 相似文献
Background: It is documented that male athletes display riskier behaviors while driving (as well as in life in general) than female athletes and nonathletes. However, the literature has reported that athletes show better driving ability than nonathletes. This paradox between behaviors and abilities motivated the present study to further understand the collision risk of varsity athletes.Objective: The current study estimates the performance differences between varsity male soccer players and male undergraduate nonathletes on (1) a driving task and (2) three perceptual–cognitive tasks (associated with collision risk prediction; i.e., Useful Field of View [UFOV] test).Methods: Thirty-five male undergraduate students (15 varsity soccer players, 20 undergraduate nonathletes) took part in this study. Driving performance was assessed during 14?min of urban commuting using a driving simulator. While completing the simulated driving task and UFOV test, the physiological responses were monitored using an electrocardiograph (ECG) to document heart rate variability (HRV).Results: Varsity soccer players showed more risky behaviors at the wheel compared to their nonathlete student peers. Varsity soccer players spent more time over the speed limit, committed more driving errors, and adopted fewer safe and legal behaviors. However, no difference was observed between both groups on driving skill variables (i.e., vehicle control, vehicle mobility, ecodriving). For subtests 1 and 2 of the UFOV (i.e., processing speed, divided attention), both groups performed identically (i.e., 17?ms). The nonathlete group tended to perform better on the selective attention task (i.e., subtest 3 of UFOV test; 63.2?±?6.2?ms vs. 87.2?±?10.7?ms, respectively; this difference was not significant, P = .76).Conclusion: Preventive driving measures should be enforced in this high-risk population to develop strategies for risk reduction in male team athletes. 相似文献
Objective: The adaptive behavior of mobile phone–distracted drivers has been a topic of much discussion in the recent literature. Both simulator and naturalistic studies suggest that distracted drivers generally select lower driving speeds; however, speed adaptation is not observed among all drivers, and the mechanisms of speed selection are not well understood. The aim of this research was to apply a driver behavioral adaptation model to investigate the speed adaptation of mobile phone–distracted drivers.
Methods: The speed selection behavior of drivers was observed in 3 phone conditions including baseline (no conversation) and hands-free and handheld phone conversations in a high-fidelity driving simulator. Speed adaptation in each phone condition was modeled as a function of secondary task demand and self-reported personal/psychological characteristics with a system of seemingly unrelated equations (SURE) accounting for potential correlations due to repeated measures experiment design.
Results: Speed adaptation is similar between hands-free and handheld phone conditions, but the predictors of speed adaptation vary across the phone conditions. Though perceived workload of secondary task demand, self-efficacy, attitude toward safety, and driver demographics were significant predictors of speed adaptation in the handheld condition, drivers' familiarity with the hands-free interface, attitude toward safety, and sensation seeking were significant predictors in the hands-free condition. Drivers who reported more positive safety attitudes selected lower driving speeds while using phones.
Conclusion: This research confirmed that behavioral adaptation models are suitable for explaining speed adaptation of mobile phone distracted drivers, and future research could be focused on further theoretical refinement. 相似文献