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41.
A longitudinal predictive design was used to test a model linking changes in structural and psychological empowerment to changes in job satisfaction. Structural equation modeling analyses revealed a good fit of the data from 185 randomly selected staff nurses to the hypothesized model. Changes in perceived structural empowerment had direct effects on changes in psychological empowerment and job satisfaction. Changes in psychological empowerment did not explain additional variance in job satisfaction beyond that explained by structural empowerment. The results suggest that fostering environments that enhance perceptions of empowerment can have enduring positive effects on employees. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
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What can we learn from resource pulses?   总被引:1,自引:0,他引:1  
Yang LH  Bastow JL  Spence KO  Wright AN 《Ecology》2008,89(3):621-634
An increasing number of studies in a wide range of natural systems have investigated how pulses of resource availability influence ecological processes at individual, population, and community levels. Taken together, these studies suggest that some common processes may underlie pulsed resource dynamics in a wide diversity of systems. Developing a common framework of terms and concepts for the study of resource pulses may facilitate greater synthesis among these apparently disparate systems. Here, we propose a general definition of the resource pulse concept, outline some common patterns in the causes and consequences of resource pulses, and suggest a few key questions for future investigations. We define resource pulses as episodes of increased resource availability in space and time that combine low frequency (rarity), large magnitude (intensity), and short duration (brevity), and emphasize the importance of considering resource pulses at spatial and temporal scales relevant to specific resource-onsumer interactions. Although resource pulses are uncommon events for consumers in specific systems, our review of the existing literature suggests that pulsed resource dynamics are actually widespread phenomena in nature. Resource pulses often result from climatic and environmental factors, processes of spatiotemporal accumulation and release, outbreak population dynamics, or a combination of these factors. These events can affect life history traits and behavior at the level of individual consumers, numerical responses at the population level, and indirect effects at the community level. Consumers show strategies for utilizing ephemeral resources opportunistically, reducing resource variability by averaging over larger spatial scales, and tolerating extended interpulse periods of reduced resource availability. Resource pulses can also create persistent effects in communities through several mechanisms. We suggest that the study of resource pulses provides opportunities to understand the dynamics of many specific systems, and may also contribute to broader ecological questions at individual, population, and community levels.  相似文献   
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Oak Ridge tank sludges that have been collected over several decades are being combined for treatment and disposal. Stabilization of the highly radioactive, mixed-waste sludges in the different tank sets has been evaluated prior to the proposed combination and treatment. This paper documents the testing of a Melton Valley Storage Tank (MVST)/Bethel Valley Evaporator Storage Tank set. Subsequent papers will discuss continued work on other tank sets and efforts to maximize the sludge loading. Grout formulations were tested in the laboratory both with a surrogate and with a sample of an actual mixed waste tank sludge from MVST W-25. Wet-sludge loadings of 50-60wt% resulted in strong wasteforms with no free water and gave a volume increase of about 40-50vol%. Resource Conservation and Recovery Act (RCRA) metals included in the surrogate testing were cadmium, chromium, lead, selenium, thallium, and mercury. The actual sludge sample was only characteristically hazardous for mercury by the Toxic Characteristic Leaching Procedure but exceeded the Universal Treatment Standard (UTS) limit for chromium. The grout formulations stabilized these two RCRA metals within UTS limits. In addition, a grout leachability index of about 9.0-10.0 was measured for both (85)Sr and (137)Cs, meeting the recommended requirement of >6.0.  相似文献   
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The diversity of shelters used in transitional settlements for internally displaced persons (IDPs) in Herat, Afghanistan is described. The information is based on a field survey undertaken in March 2002 and highlights the adaptation techniques, which IDPs undertake to improve any provided shelter. Potential areas for improvement are indicated; for example, the possibility for using insulated, demountable liners to prevent cold-related deaths without sacrificing shelter flexibility along with the likely need for better agency coordination of the shelter responses they provide. The wider context in which the technical recommendations would be implemented must also be considered. Such issues include agency resources, political impediments to providing the desired option, and the preference of many IDPs that the best shelter would be their home.  相似文献   
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