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61.
This study describes the relations between different dimensions of leadership commitment, safety climate and attitudes toward change, and how these affect employee perceptions of safety during organizational change in a high risk environment. We collected data from a European national air navigation services provider during a volatile 3-year corporatization process that ended in the sudden collapse of a deliberate change implementation project. Surprisingly, despite visible signs of internal and external stress caused by the volatile and disruptive change process, we did not observe any change in the traditional safety metrics of incident and accident reporting during the study. The study is based on a large survey (n = 422) of individual attitudes and perceptions of safety climate, perception of leadership commitment to safety, attitudes to organizational change, and perception of safety. The data support the claim that perception of safety at least, in part, depends on individual perceptions of the leadership’s commitment to safety, and the safety climate in place at a given point in time. The model shows how employee perceptions of the leadership’s commitment to safety and safety climate are related to both attitudes toward change, and to perceived safety.  相似文献   
62.
Integrated Assessment (IA) models aim at providing information- and decision-support to complex problems. This paper argues that uncertainty analysis in IA models should be user-driven in order to strengthen science–policy interaction. We suggest an approach to uncertainty analysis that starts with investigating model users’ demands for uncertainty information. These demands are called “uncertainty information needs”. Identifying model users’ uncertainty information needs allows focusing the analysis on those uncertainties which users consider relevant and meaningful. As an illustrative example, we discuss the case of examining users’ uncertainty information needs in the SEAMLESS Integrated Framework (SEAMLESS-IF), an IA model chain for assessing and comparing alternative agricultural and environmental policy options. The most important user group of SEAMLESS-IF are policy experts at the European and national level. Uncertainty information needs of this user group were examined in an interactive process during the development of SEAMLESS-IF and by using a questionnaire. Results indicate that users’ information requirements differed from the uncertainty categories considered most relevant by model developers. In particular, policy experts called for addressing a broader set of uncertainty sources (e.g. model structure and technical model setup). The findings highlight that investigating users’ uncertainty information needs is an essential step towards creating confidence in an IA model and its outcomes. This alone, however, may not be sufficient for effectively implementing a user-oriented uncertainty analysis in such models. As the case study illustrates, it requires to include uncertainty analysis into user participation from the outset of the IA modelling process.  相似文献   
63.
64.
Telomeric attrition has repeatedly been found to correlate with the ageing of organisms; however, recent research is increasingly showing that the determinants of attrition dynamics are not well understood. This study examined the relative telomere lengths in Eastern mosquitofish, Gambusia holbrooki, kept at different temperatures and at different ages. Newly born fry were randomly selected for one of four treatment groups: 20, 30, 20–30, and 30–20 °C, where the third and fourth treatment groups were gradually changed from their starting temperature to their final temperature between days 10 and 14. Telomere length was measured, and it was found that length decreased with age and that fish exposed to the 20 °C treatment had significantly shorter telomeres than those that received the 30–20 °C treatment. Telomeric attrition with age agrees with results previously found in studies of telomeres; however, the variation in attrition with temperature was not simply predictable and may be the synergistic effects of temperature and some other factor.  相似文献   
65.
Polychlorinated biphenyls (PCBs) and organic pesticides (i.e., DDTs) were measured in long finned eels (Anguilla dieffenbachii) in 17 streams on the west coast of South Island, New Zealand. Very low levels of PCBs and low levels of ppDDE were found. The concentrations of PCBs and ppDDE were not correlated within sites indicating that different processes determined the levels of the two pollutants in New Zealand eels. The PCBs probably originate from atmospheric transport, ppDDE levels are determined by land use and are higher in agriculture areas. The low contamination level of these aquatic systems seems to be a function of a low input from both long and short-range transport as well as few local point sources. No correlation could be found between lipid content and persistent organic pollutants (POPs) concentration (as shown in previous studies) in the eels which could be explained by low and irregular intake of the pollutants.  相似文献   
66.
Bis(4-chlorophenyl) sulfone (BCPS) is a high production volume chemical (HPVC) applied in thermostable polymers. BCPS has been detected as an environmental contaminant both in Europe and in North America but it is still not a commonly studied pollutant. In this study, three Baltic Sea fish species; herring (Clupea harengus), salmon (Salmo salar) and perch (Perca fluviatilis) from the Swedish coast, and one inland fish species, arctic char (Salvelinus alpinus), were analysed to screen for the occurrence and distribution of BCPS. Salmon and arctic char, were sampled in the early 1970s as well as the late 1990s. Fish eating grey seal (Halichoerus gryphus) and guillemot (Uria aalge) from the Baltic Sea were included to screen for whether BCPS biomagnify or not. The representativeness of the analysed samples for studying bioaccumulation of environmental pollutants was compared through analysis of two well known persistent and bioaccumulating compounds, 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), and 4,4'-DDE. Pooled muscle and blubber samples based on 4-10 individuals were used for analysis, as well as individual samples of grey seal blubber. 2,4,4'-Trichlorodiphenyl sulfone, was synthesised and applied as an internal standard. BCPS was detected in all marine samples but in only one of the fresh water fish samples. The highest BCPS concentrations detected, 1600 and 1900 ng/g lipid weighet (l.w.), were found in muscle from Baltic guillemot. The results indicate that BCPS is bioaccumulated in both grey seal and guillemot, and that the guillemot has higher concentrations of BCPS than the grey seal (50-500 ng/g l.w.). The concentrations found in different species of fish from the Baltic Sea ranged between 15-37 ng/g l.w. and lower concentrations were found in freshwater species (n.d.-1.8 ng/g l.w.). The present study shows that BCPS is found in all investigated species of wildlife but, in most species, still at low concentrations. However, the guillemot has levels in the low ppm range indicating a considerable biomagnification of BCPS in this species.  相似文献   
67.
This paper gives an overview of the cadmium (Cd) situation in agricultural systems and human exposure in Sweden. Cadmium levels in agricultural soils (the plow layer) increase by 0.03% to 0.05% per year. Feed can give substantial contributions of Cd to local agricultural systems. Effects on human kidney function are indicated by some measurements already at today's exposure levels. If food products reach the maximum permissible levels given by the European Union, 10% to 25% of the Swedish population will be exposed to Cd levels above the provisional tolerable weekly intake (PTWI 7 microg Cd kg(-1) body weight). Sensitive groups in the population are individuals with low iron status (mainly women) and kidney disorders. Recent studies indicate that Cd plays a role in osteoporosis and that further research is needed to clarify if Cd is neurotoxic in early developmental stages. Firm actions have to be taken in order to stop a further increase of Cd in agricultural soils. Suggestions for prevention and measures are given in this paper.  相似文献   
68.
A method for the analysis of polychlorinated naphthalenes (PCN) has been developed. It is based on a simple clean-up procedure using activated carbon and a mass fragmentographic analysis using the negative ions formed during chemical ionization (NCI). Unlike the technical PCN products we have analyzed, a few isomerides containing four to six chlorine atoms dominate the PCN pattern in the environmental samples. The levels found in samples of biota from fresh water and marine environments in Sweden were between 3 and 62 ng PCN per gram lipid.  相似文献   
69.
Olsson L  Ardö J 《Ambio》2002,31(6):471-477
The Kyoto Protocol opens new possibilities for using the biosphere as a carbon sink. Using agro-ecosystems as carbon sinks may be the most appropriate practice from both environmental and socioeconomic points of view. Degraded agro-ecosystems in Africa might benefit significantly from the improved land management that would be part of a carbon sequestration program. There are vast areas of these agro-ecosystems in Africa and their rehabilitation is an urgent matter. We agree with UNEP that there are potentially important synergies to be made between the Convention on Climate Change, the UN Convention to Combat Desertification and the UN Convention on Biodiversity. In this paper, we have investigated the potential for increasing soil carbon content in semiarid agro-ecosystems in the Sudan and found that increasing fallow periods will result in increased soil carbon content and converting marginal agricultural areas to rangeland will restore the carbon levels to 80% of the natural savannah carbon levels in 100 years. The economic gain from a future carbon sequestration program has the potential of a significant contribution to the household economy in these agro-ecosystems.  相似文献   
70.
When seeking to resolve complex land-management issues, geographical assessment of resources that are in short supply or in dispute can aid the communication of knowledge and the understanding among and between different stakeholders. In this paper, we illustrate how remote sensing and GIS can be used to gather and compile information regarding land-use activities and patterns among reindeer herders and other land users (forestry, mining, tourism, etc) in northern Sweden. The project represents a novel user-oriented effort largely based on the work carried out by the principal end user, i.e. the reindeer herders themselves. The basis for development of land-use plans for reindeer husbandry, was the following: to collect and digitally systemize traditional ecological and landscape knowledge of reindeer habitat use; to integrate this information with results from field inventories and satellite-based vegetation classifications; to map activities of other land users. The resulting land-use plans provide information that can facilitate consultation between the reindeer herders and other stakeholders and can facilitate operational work in reindeer management. This project can serve as a model for participatory involvement and planning, bringing indigenous knowledge and advanced remote-sensing techniques together in an interactive process.  相似文献   
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