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481.
482.
An Erratum has been published for this article in Journal of Organizational Behavior 26(7) 2005, 873. Previous research on the relationship between alternative employment opportunities and cooperation has neglected the distinction between evaluations and restrictions. Thus, one cannot analyze the relationship between attractiveness of alternative employment opportunities and organizational citizenship behaviors (OCB) under different levels of perceived ease of finding alternative employment. In a pilot study with N = 149 German employees, we confirm the proposed distinction with confirmatory factor analyses. Based on power‐dependence theory and rational choice models, we predict that under high ease the relationship between attractiveness and OCB should be more strongly negative than under conditions of low ease. In addition, we hypothesize that the interaction between attractiveness and ease should be greater for OCB than for task performance because task performance is exchanged in a relationship with an enforceable, binding contract, while OCB is voluntarily. Results from moderated multiple regression analysis on N = 86 German professional–supervisor dyads support our prediction for a negative relationship between attractiveness and OCB under high ease. Under low ease, we find a positive relationship between attractiveness and OCB. Moreover, there was no relationship with the interaction and task performance. Implications of the findings both for extra‐role and job mobility theory formation and research are discussed. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
483.
484.
Alexander Lukeneder Mathias Harzhauser Stefan Müllegger Werner E. Piller 《Marine Biology》2008,154(1):175-182
Stable isotopes (δ18O and δ13C) were measured in successive chambers of the aragonitic shells of the small deep-sea squid Spirula spirula (Linnaeus 1758) (class Cephalopoda, subclass Coleoidea, order Sepioidea, family Spirulidae) to determine whether their depth distributions
change with age. The spiral shells, ranging in diameter from 18 to 23 mm (30–38 chambers), were collected between 2000 and
2006 from beaches in six widely separated locations in three oceans, the Atlantic (Tobago and Canary Islands), Indian (Madagascar,
Maldives, and Perth, Australia), and Pacific Oceans (Ulladulla, Australia). The patterns for both isotopes were highly correlated
in specimens from all six sites. The δ18O data suggest that after hatching at depths >1,000 m at temperatures of 4–6°C, the squid migrate into shallower, warmer waters
at 12–14°C at depths of 400–600 m. Subsequently, the increasing δ18O values suggest a migration back into somewhat cooler, deeper habitats. The δ13C values also revealed three ontogenetic stages in all six specimens, including a major shift from positive to negative values,
which probably corresponds to sexual maturation, the initiation of reproduction, and concomitant changes in diet. In three
of the six specimens (from Tobago, Canary Islands, and Maldives) a fourth embryonic stage (not detected in the oxygen data)
was accompanied by markedly less positive δ13C values in the first few chambers. These data, combined with the scanty life history information from previous studies of
S. spirula, can be used to compare the habitat requirements of related extant and fossil cephalopod genera.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
485.
Hans -Martin Mulisch Werner Winter Hermann H. Dieter 《Environmental Sciences Europe》2000,12(5):269-278
To include consequences emanating from former military sites on the drinking water supply, a catalog of criteria has been developed which permits the determination and assessment of the hazards in general and their impact on human health in particular. The assessment criteria correspond to the special requirements and standards for drinking water hygiene and protection in Germany. The criterion catalog is a completion module to the usual praxis and existing conceptions, and has proved its practical value in the initial assessment of military sites in the new federal states of Germany. The scheme is a control instrument suitable for obtaining an assessment concerning the extent to which drinking-water resources are and will be affected by former waste disposal and other contaminated sites at the present and in the future. 相似文献
486.
Alfred Becker Volker Wenzel Valentina Krysanova Werner Lahmer 《Environmental Modeling and Assessment》1999,4(4):243-257
The paper introduces an approach for the analysis of global change impacts on river basins or regions. This approach is quite general and can be transferred to any region or river basin of interest on earth. The first application of the approach was in the Elbe river basin, with primary focus on the hydrologic model part and on the integration of crop growth and nitrogen dynamics. Finally, concepts for the integration of socio-economic aspects in the analysis are introduced. 相似文献
487.
K. Butterbach-Bahl M. Kahl L. Mykhayliv C. Werner R. Kiese C. Li 《Atmospheric environment (Oxford, England : 1994)》2009,43(7):1392-1402
Soils are a significant source for atmospheric NO. However, due to the limited number of measurements and in view of the high temporal and spatial variability of NO emissions, as originating from dependencies from a series of environmental constraints such as soil properties, meteorology or N fertilization, inventories of soil NO emissions are still highly uncertain. In this work, the agricultural DNDC model was modified and applied on site scale in order to evaluate its capability to simulate soil NO emissions. DNDC captured differences in the magnitude of NO emissions between sites, but was less successful when simulating observed day-by-day variations. However, major peak emission events, e.g. due to fertilizer application or following rainfall events, were mostly simulated. DNDC as well as its forest version Forest-DNDC were finally linked to a GIS to calculate NO emissions from agricultural and forest soils across Europe. Using the same databases for agricultural soils, we also compared our estimate with other commonly used methodologies (Skiba-EMEP/CORINAIR, Yienger and Levy, Stehfest and Bouwman). A canopy reduction factor was not applied in this study. Estimates for NO emissions for agricultural soils for EU15 states varied in a range of 48.9–189.8 kt NO-N for the year 2000 depending on the approach used (Yienger and Levy > DNDC > Stehfest and Bouwman > Skiba-EMEP/CORINAIR). For forests, using the model Forest-DNDC as the only approach, we calculated soil NO emissions to be 75.1 kt NO-N yr?1. The results show that soils in EU15 states are significant sources of atmospheric NO, though the share of soil NO emissions on total NOx emissions (incl. NOx emissions by combustion processes) in EU15 was only 4–6%. Given that soil NO emissions are largely driven by the availability of inorganic nitrogen (fertilization) and temperature, emissions are larger during the vegetation period. Especially during early summer when fertilizer-induced NO emissions from agricultural soils are peaking, the contribution of soil emissions to total NOx emissions may most likely be well above 10%. 相似文献
488.
Kevin E. Percy Sirkku Manninen Karl-Heinz Häberle H. Werner Rainer Matyssek 《Environmental pollution (Barking, Essex : 1987)》2009,157(5):1657-1665
We examined the effect of ozone (O3) on Norway spruce (Picea abies) needle epicuticular wax over three seasons at the Kranzberg Ozone Fumigation Experiment. Exposure to 2× ambient O3 ranged from 64.5 to 74.2 μl O3 l−1 h AOT40, and 117.1 to 123.2 nl O3 l−1 4th highest daily maximum 8-h average O3 concentration. The proportion of current-year needle surface covered by wax tubes, tube aggregates, and plates decreased (P = 0.011) under 2× O3. Epistomatal chambers had increased deposits of amorphous wax. Proportion of secondary alcohols varied due to year (P = 0.004) and O3 treatment (P = 0.029). Secondary alcohols were reduced by 9.1% under 2× O3. Exposure to 2× O3 increased (P = 0.037) proportions of fatty acids by 29%. Opposing trends in secondary alcohols and fatty acids indicate a direct action of O3 on wax biosynthesis. These results demonstrate O3-induced changes in biologically important needle surface characteristics of 50-year-old field-grown trees. 相似文献
489.
Critical evaluation of PAH source apportionment tools using data from the Swiss soil monitoring network 总被引:1,自引:0,他引:1
Brändli RC Bucheli TD Ammann S Desaules A Keller A Blum F Stahel WA 《Journal of environmental monitoring : JEM》2008,10(11):1278-1286
In this study a large dataset on the polycyclic aromatic hydrocarbon (PAH) content of Swiss soils was analysed to evaluate two source apportionment tools, i.e., characteristic PAH ratios/molecular markers and a linear mixing model. Population density and total organic carbon (TOC) content were identified by a multiple regression model as independently and positively influencing the PAH concentrations in Swiss background soil. Specifically, TOC was more strongly positively correlated with the sum of light PAH (naphthalene to phenanthrene) than with the sum of heavy PAH (anthracene to benzo[ghj]perylene), whereas population density was more strongly positively correlated with the sum of heavy PAH than with light PAH. In addition, the sum of the heavy PAH as well as the total sum correlated negatively with sample site altitude. It is therefore hypothesised that heavy PAH are less mobile, whereas light PAH were closer to equilibrium with TOC in the soil. Similar results were found for polychlorinated biphenyls (PCB). The characteristic ratios and molecular markers pointed to pyrogenic origin of PAH in Swiss background soil but did not allow for further differentiation of individual fuel contributions, even though attempts to take environmental fractionation processes into account were made. The comparison of three soil profiles identified with a linear mixing model from the pattern of 16 PAH with >300 PAH emission profiles from the literature suggested urban dust, wood combustion and binders from asphalt as PAH sources. However, also here, environmental fractionation processes probably obscured source characteristic PAH ratios and fingerprints, which thus need to be interpreted with caution. 相似文献
490.
Brils J Quevauviller P Slob A Blind M Davy T Carere M Amorsi N Brack W Borchers U Thompson C Villessot D 《Journal of environmental monitoring : JEM》2010,12(12):2204-2206
The first generation of WFD River Basin Management Plans is now available. This is a formidable achievement and a great step towards addressing Europe's deteriorated river systems. However, plans are only words: only the actual implementation of the selected measures will result in achievement of good ecological and chemical status. The WFD Lille 2010 Conference pointed out that a lot of new, but so far unused scientific knowledge is available to improve the effectiveness of selected measures or to inspire the introduction of complementary measures. Furthermore, the complexity in terms of the functioning of the water system, its interaction with the socio-economic system and the uncertain consequences of climate change, urges a 'learning-by-doing' approach. This approach should be applied in well-designed, -coordinated and -monitored learning catchments. 相似文献