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61.
A longitudinal study of determinants of perceived employability 总被引:1,自引:0,他引:1
Employability is highly important to individuals in coping with job insecurity. Although many employability models have been developed, few studies have tested determinants of employability empirically. This longitudinal study aims to analyze core determinants of perceived employability. These were tested using a sample of 465 employees (time 1) taken from four companies in Switzerland and surveyed at three points in time. In order to include data from all participants, we used multilevel analysis (level 1: time, level 2: person). Results showed that education, support for career and skill development, current level of job‐related skills, and willingness to change jobs were significant predictors of perceived employability. Contrary to our hypotheses, willingness to develop new competencies, opportunity awareness, and self‐presentation skill failed to predict perceived employability. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
62.
Non-work experiences during the weekend provide opportunities to recover from work demands and to replenish lost resources. This longitudinal study examined how specific recovery experiences during the weekend (relaxation, mastery, control, and detachment), as well as non-work hassles, were associated with specific positive and negative affective states during the following workweek. Participants (N = 229) completed surveys before the weekend, during the weekend, and during the following workweek. Hierarchical regression analyses revealed that after controlling for affective states the previous week, recovery experiences during the weekend significantly explained variance in affective states at the end of the weekend and during the following workweek. Suggestions for future research include a closer examination of the role of individual differences, self-regulation, and specific work demands in employee stress recovery. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
63.
Schmidt S 《Journal of environmental radioactivity》2005,78(1):1-10
A systematic survey of dissolved uranium activity was carried out in the Seine and the Marne over one year. A small watershed, the Grand Morin, included in the Seine one, was also investigated from stream to medium-sized rivers. The Melarchez stream exhibits low but variable dissolved 238U levels (3.3 +/- 2.0 mBq l(-1)). Thereafter, uranium activities show a rapid increase to reach, from the Grand Morin River, a rather constant range (8-11 mBq l(-1)). On the Marne before the confluence with the Seine, dissolved 238U is nearly invariable (9.1 +/- 0.8 mBq l(-1)), for flow rates comprised between 60 and 423 m3 s(-1). Dissolved 238U in the Seine corresponds to almost triple the global mean riverine uranium concentration. In the estuary of the Seine, uranium shows a gradual increase, resulting from conservative mixing of river with sea waters. 相似文献
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Plutonium isotopes in the Rh?ne River originate from both the weathering of the catchment basin contaminated by global atmospheric fallout, and the liquid effluents released from the Marcoule reprocessing plant since 1961. Due to a new treatment process applied to the liquid effluents, a decrease of two orders of magnitude in the industrial plutonium discharged into the River Rh?ne has been registered from 1991. Today, 238Pu industrial inputs to the River Rh?ne are still about 10 times higher than those derived from global fallout, while 239+240Pu inputs from industrial and global fallout sources are of similar importance, i.e. 1 GBq y(-1). Our results indicate that the river sedimentary compartment act either as a sink or a delayed-source term of plutonium for the freshwaters depending on the hydraulic regime and flood events. This compartment may then represent an important industrial delayed-source term for the River Rh?ne freshwaters in the coming years as the Marcoule reprocessing plant is being dismantled. These results were obtained from samples collected from the lower course of the River Rh?ne over the 1987-1998 period and analysed for 238Pu and 239+240Pu activities. Both river sedimentary inventories of plutonium isotopes and effective outputs from the River Rh?ne towards the Gulf of Lions have been estimated for each year over the 1945-2000 period. Regarding 239+240Pu, the sedimentary inventory accumulated since 1945 is estimated to be 172+/-35 GBq. If mobile, this amount represents a significant delayed-source term of plutonium on the scale of the Rh?ne watershed. 相似文献
66.
Haas K Köhler U Diehl S Köhler P Dietrich S Holler S Jaensch A Niedermaier M Vilsmeier J 《Ecology》2007,88(11):2915-2925
It is notoriously difficult to study population interactions among highly mobile animals that cannot be meaningfully confined to experimental plots of limited size. For example, migratory water birds are believed to suffer from competition with resident fish populations for shared food resources. While observational evidence in support of this hypothesis is accumulating, replicated experiments addressing this issue at the proper spatial scale are lacking. Here, we report from a replicated whole-system experiment in which we stocked large (0.07 km2), shallow (< or =2.5 m deep), highly eutrophic ponds in the bird protection area "Ismaninger Speichersee mit Fischteichen" with different densities of carp and assessed the responses of water birds and their food resources during summer over several years. In all years, the biomasses of benthic macroinvertebrates, macroalgae, and macrophytes as well as the densities of herbivorous, carnivorous, and omnivorous water birds were reduced in carp ponds compared to fishless ponds. The negative effects of carp on food resources and on the numbers of water birds feeding in carp ponds increased over the season (May-September) and were stronger at high than at low stocking densities of carp. Consequently, differences in resource densities between ponds with and without carp increased, and the ranking of ponds with respect to resource densities became more predictable over the season. These factors may have contributed to a seasonal improvement of the birds' abilities to track resource densities across ponds, as suggested by tight correlations of bird numbers on ponds with resource densities late, but not early, in the season. 相似文献
67.
Thomas Kupper Diane Bürge Hans Jörg Bachmann Sabine Güsewell Jochen Mayer 《Waste management (New York, N.Y.)》2014,34(5):867-874
The production of compost and digestate from source-separated organic residues is well established in Europe. However, these products may be a source of pollutants when applied to soils. In order to assess this issue, composts, solid and liquid digestates from Switzerland were analyzed for heavy metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) addressing factors which may influence the concentration levels: the treatment process, the composition, origin, particle size and impurity content of input materials, the season of input materials collection or the degree of organic matter degradation.Composts (n = 81) showed mean contents being at 60% or less of the legal threshold values. Solid digestates (n = 20) had 20–50% lower values for Cd, Co, Pb and Zn but similar values for Cr, Cu and Ni. Liquid digestates (n = 5) exhibited mean concentrations which were approximately twice the values measured in compost for most elements. Statistical analyses did not reveal clear relationships between influencing factors and heavy metal contents. This suggests that the contamination was rather driven by factors not addressed in the present study.According to mass balance calculations related to Switzerland, the annual loads to agricultural soils resulting from the application of compost and digestates ranged between 2% (Cd) and 22% (Pb) of total heavy metal loads. At regional scale, composts and digestates are therefore minor sources of pollution compared to manure (Co, Cu, Ni, Zn), mineral fertilizer (Cd, Cr) and aerial deposition (Pb). However, for individual fields, fertilization with compost or digestates results in higher heavy metal loads than application of equivalent nutrient inputs through manure or mineral fertilizer. 相似文献
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69.
Dissolved uranium ((238)U(D)) was measured within the Gironde fluvial-estuarine system (France), which is well known for its heavy metal pollution and its subsequent environmental effects. Dissolved (238)U activities exhibit the highest levels and variability in the small watersheds of the Isle and Riou-Mort rivers, ascribed to low discharges and the occurrence of peculiar features (local U ore deposits; Permian layers). The major tributaries of the Gironde Estuary: Garonne, Lot and Dordogne, show rather stable (238)U(D), higher than the global mean riverine uranium activity. In the Gironde Estuary (238)U(D) behaves conservatively along the river-estuary-ocean transect. Dissolved (238)U distribution in the Gironde fluvial-estuarine system can be explained by the characteristics of considered drainage basins. There is no evidence of anthropogenic pollution. 相似文献
70.
Wolfgang Cramer Uta Fritsch Rik Leemans Sabine Lütkemeier Dagmar Schröter Allan Watt 《Regional Environmental Change》2008,8(3):125-134
Biodiversity is essential for multiple aspects of human life and well-being, but many current assessments of the functioning
of biodiversity and ecosystems, understanding of risks posed by environmental change and the best practice of their management
of ecosystems are lacking a unified scientific and conceptual basis. Methods such as scenario analysis, and terms such as
ecosystem services, are widely used, but their meaning is understood in many different ways depending on context, user needs
and experience of researchers. In order to advance the conceptual basis for ecosystem analysis and management in a rapidly
changing world, as well as the ability of young scientists to reflect upon these concepts, we have organised five 2-week-long
summer schools in Peyresq, a remote village in the Southern French Alps. In total 173 participants have worked intensively
with 69 experienced researchers and a team of conveners and tutors in order to discuss a broad range of views on topics on
ecosystem analysis and functioning. Topics ranged from conditions of and threats to various ecosystems due to environmental
change, models and scenarios for assessment, stakeholder perceptions and needs for information, to the social and economic
contexts for biodiversity. We report our experience from these schools, present the training concept which has emerged from
them and suggest lines of further development.
相似文献
Wolfgang CramerEmail: |