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51.
Coastal eutrophication is expected to increase due to expanding and intensifying agriculture which causes a large amount of soil-associated P to be transported into aquatic systems. We performed anaerobic long-term incubations on field soil to mimic the conditions that eroded soil encounters in brackish sediments. The release of P from soil increased with the amount of labile organic C (acetate) addition and decreased with the soil/solution ratio. We deduce that in less-productive brackish systems, microbial Fe reduction allows for the maintenance of the coupled cycling of Fe and P and restricts the amount of P entering the oxic water. In more eutrophic systems, the formation of Fe sulfides as a result of SO4 reduction inactivates Fe, and leads to a higher release of P, thus generating an adverse feedback effect. The dependence of the fate of soil-bound Fe and P on the trophic status of the receiving water should be recognized in eutrophication management.  相似文献   
52.
This paper presents findings from an extensive study intofactors that impact upon the high rate of injuries due to mechanical equipment, especially in small manufacturing firms. Issues relating to knowledge of health and safety issues and to management practices have been shown to be extremely important with regards to safety in smaii businesses. Knowledge and awareness of hazards were found to be relatively low and few respondents, especially managers, had received adequate safety training. Managers did not regard the identification and control of risks as a priority. Workplaces generally lacked effective safety management procedures such as safety rules and regulations, procedures for recording and learning from accidents, and clearly defined responsibilities for safety. Some issues requiring further investigation, and some recommendations for improving safety in small businesses, are presented.  相似文献   
53.
This article reports the results of a study investigating the nature and extent of small manufacturing business owners’ knowledge of Occupational Health and Safety (OHS) issues. Interviews were conducted with 33 owners of small manufacturing businesses in Sydney, Australia. Results showed that whereas the majority of owners had basic awareness of the existence of OHS legislation, they were often unaware about the extent of their legal OHS responsibilities. Owners were found to have minimal OHS training and practical OHS expertise. Lack of appropriate industry specific OHS information was found to be a major factor that inhibited the owners’ ability to deal with OHS issues effectively.  相似文献   
54.

The contributions of local community action groups to environmental care and restoration is usually justified and evaluated in terms of improvements to environmental quality. This article explores social benefits in the form of increases in social capital and action competence that also flow from their actions, benefits that may not only help restore degraded but also contribute to the stock of good will and skill in the community that may even prevent or minimise future environmental problems. This article documents the emergence of action competence and social capital in two community catchment groups in South-East Queensland. The findings suggest that social capital is enhanced through processes of community participation in the catchment consultation processes. The article concludes that the relationship between social capital and action competence is complementary, with social capital and action competence being mutually enhanced by the social learning that accrues from the process of community participation.  相似文献   
55.
The objective of this paper is to analyse the impacts of climate change on a pine forest stand in Central Siberia (Zotino) to assess benefits and risks for such forests in the future. We use the regional statistical climate model STARS to develop a set of climate change scenarios assuming a temperature increase by mid-century of 1, 2, 3 and 4 K. The process-based forest growth model 4C is applied to a 200-year-old pine forest to analyse impacts on carbon and water balance as well as the risk of fire under these climate change scenarios. The climate scenarios indicate precipitation increases mainly during winter and decreases during summer with increasing temperature trend. They cause rising forest productivity up to about 20 % in spite of increasing respiration losses. At the same time, the water-use efficiency increases slightly from 2.0 g C l?1 H2O under current climate to 2.1 g C l?1 H2O under 4 K scenario indicating that higher water losses from increasing evapotranspiration do not appear to lead to water limitations for the productivity at this site. The simulated actual evaporation increases by up to 32 %, but the climatic water balance decreases by up to 20 % with increasing temperature trend. In contrast, the risk of fire indicated by the Nesterov index clearly increases. Our analysis confirms increasing productivity of the boreal pine stand but also highlights increasing drought stress and risks from abiotic disturbances which could cancel out productivity gains.  相似文献   
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The contributions of local community action groups to environmental care and restoration is usually justified and evaluated in terms of improvements to environmental quality. This article explores social benefits in the form of increases in social capital and action competence that also flow from their actions, benefits that may not only help restore degraded but also contribute to the stock of good will and skill in the community that may even prevent or minimise future environmental problems. This article documents the emergence of action competence and social capital in two community catchment groups in South-East Queensland. The findings suggest that social capital is enhanced through processes of community participation in the catchment consultation processes. The article concludes that the relationship between social capital and action competence is complementary, with social capital and action competence being mutually enhanced by the social learning that accrues from the process of community participation.  相似文献   
59.
Solid-state 15N NMR was applied to the aqueous extracts of a 13C-enriched plant slurry (Lolium perenne), anaerobically incubated with 15N3-trinitrotoluene (TNT). Almost all 15N3-TNT transformation products became covalently bound to the plant-derived organic material extractable with water. DCPMAS 15N 13C NMR revealed a three-step reaction scheme. After reduction of TNT, the aryl amines are acetylated. Subsequent alkylation of the resulting amides strengthens the incorporation of TNT-transformation products into humic material. Comparable results have been recently obtained under aerobic conditions, which indicates that this pathway is a common process during biological TNT transformation.  相似文献   
60.
Glucocorticosteroids (GCs) of the hypothalam–pituitary–adrenal axis play a role in association with both stressful events and daily life processes. However, relatively little is known about the role of GCs in relation to daily and seasonal life processes in animals in the wild. In this paper, we present data on basal levels of plasma corticosterone CORT in chicks of a pelagic seabird, the thin-billed prion, Pachyptila belcheri, during two predictable changes in demands, the daily activity pattern and the preparation for fledging. By comparing chicks fed recently with unfed chicks, we test how GC levels are modified according to nutritional condition. In accordance with their nocturnal feeding rhythm, chicks had a clear daily rhythm with increased CORT secretion at night, but CORT levels during the active phase were also highly elevated in unfed chicks compared with fed chicks. Close to fledging, chicks rapidly increased basal CORT levels, and again unfed chicks had higher levels than fed chicks, although the age effect here was stronger than the effect of recent feeding. The present data thus support the hypothesis that GC levels are adjusted to life stages with predictable changes in demands, but food availability and/or internal energy stores also affect the level to which GCs increase.  相似文献   
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