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91.
The purpose of this study was to examine the factor structure of the transformational leadership model in human service teams. As the nature of this work environment mandates certain management‐by‐exception practices, patterns of correlations between perceptions of active and passive management‐by‐exception behaviors and transformational, transactional, and laissez‐faire leadership were of interest. 236 leaders and 620 subordinates from 54 mental health teams completed the Multifactor Leadership Questionnaire, form 8Y. Results suggest that active and passive management‐by‐exception factors are independent constructs. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
92.
Andrea Hartwig Ursula Kasten Kwabena Boakye‐Dankwa Regina Schlepegrell Detmar Beyersmann 《毒物与环境化学》2013,95(4):205-215
Literature data concerning the genotoxicity of cobalt salts have been conflicting. To establish appropriate incubation conditions, we conducted a series of uptake studies, before genotoxicity was determined by DNA strand break induction in HeLa cells and mutagenicity in V79 Chinese hamster cells. Co(II) is taken up by HeLa cells in a concentration‐dependent manner and is accumulated inside the cell. The uptake is preceded by a fast association step to the outer membrane, with no saturation up to 24 h. DNA strand breaks as determined by nucleoid sedimentation are induced at concentrations as low as 50μMCoCl2. The induction is time‐dependent, showing the highest number of breaks after 4h incubation with no further increase up to 24h. CoCl2 is mutagenic at the HPRT‐locus, enhancing the spontaneous mutation frequency 4.2‐fold at 100μ?. Besides direct interactions with DNA, the mutagenicity of CoCl2 could also be due to a decrease in the Fidelity of DNA polymerisation. 相似文献
93.
The present study simultaneously examined people's perceptions of person–organization (PO) and person–supervisor (PS) fit and related these perceptions to employees' commitments. Three‐hundred‐and‐sixty employee–supervisor dyads from Taiwanese organizations reported about their PO fit and PS fit perceptions. In addition, supervisors reported about their perceptions of fit and guanxi with each of their employees. Results indicated that PO and PS fit perceptions both had an independent and additive relationship with organizational commitment. The link between employee PS fit perceptions and organizational commitment was mediated by commitment to the supervisor. Both employee and supervisor fit perceptions contributed to commitment to the supervisor through their influence on the quality of the leader‐member exchange (LMX). Guanxi could not explain additional variance in LMX and supervisor commitment. Implications for theory and practices regarding person–environment fit, commitment, and LMX are discussed. The study findings offered suggestions for a new Theory of Multiple Fits. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
94.
Karen L. Stals Matthew Wakeling Júlia Baptista Richard Caswell Andrew Parrish Julia Rankin Carolyn Tysoe Garan Jones Adam C. Gunning Hana Lango Allen Lisa Bradley Angela F. Brady Helena Carley Jenny Carmichael Bruce Castle Deirdre Cilliers Helen Cox Charu Deshpande Abhijit Dixit Jacqueline Eason Frances Elmslie Andrew E. Fry Alan Fryer Muriel Holder Tessa Homfray Emma Kivuva Victoria McKay Ruth Newbury-Ecob Michael Parker Ravi Savarirayan Claire Searle Nora Shannon Deborah Shears Sarah Smithson Ellen Thomas Peter D. Turnpenny Vinod Varghese Pradeep Vasudevan Emma Wakeling Emma L. Baple Sian Ellard 《黑龙江环境通报》2018,38(1):33-43
针对传统教与学算法在解决复杂多峰函数优化问题时,具有局部最优且搜索开发能力较差的缺点,提出了一种改进的多学习教与学优化算法,新算法为学员的每一维加入不同的教学因子,设计了基于学员均值比较的教师选择策略和向教师及学员学习的多学习策略。基于多个单峰和多峰函数的仿真结果表明,新算法跟传统的、改进的教与学算法相比,在稳定性、寻优精度和收敛速度方面更具优势。 相似文献
95.
Nazario D. Ramírez‐Beltran Joan Manuel Castro Eric Harmsen Ramón Vásquez 《Journal of the American Water Resources Association》2008,44(4):847-865
Abstract: A practical methodology is proposed to estimate the three‐dimensional variability of soil moisture based on a stochastic transfer function model, which is an approximation of the Richard’s equation. Satellite, radar and in situ observations are the major sources of information to develop a model that represents the dynamic water content in the soil. The soil‐moisture observations were collected from 17 stations located in Puerto Rico (PR), and a sequential quadratic programming algorithm was used to estimate the parameters of the transfer function (TF) at each station. Soil texture information, terrain elevation, vegetation index, surface temperature, and accumulated rainfall for every grid cell were input into a self‐organized artificial neural network to identify similarities on terrain spatial variability and to determine the TF that best resembles the properties of a particular grid point. Soil moisture observed at 20 cm depth, soil texture, and cumulative rainfall were also used to train a feedforward artificial neural network to estimate soil moisture at 5, 10, 50, and 100 cm depth. A validation procedure was implemented to measure the horizontal and vertical estimation accuracy of soil moisture. Validation results from spatial and temporal variation of volumetric water content (vwc) showed that the proposed algorithm estimated soil moisture with a root mean squared error (RMSE) of 2.31% vwc, and the vertical profile shows a RMSE of 2.50% vwc. The algorithm estimates soil moisture in an hourly basis at 1 km spatial resolution, and up to 1 m depth, and was successfully applied under PR climate conditions. 相似文献
96.
A time‐lagged investigation of the impact of coworker behavior on the effects of demographic dissimilarity
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Although it is clear that coworker absenteeism, tardiness, and turnover can influence an employee's actions, scholars have yet to consider the impact of relational demography on the adoption of these behavioral norms. Inspired by social identity, situational strength, and attraction‐selection‐attrition theories, we proposed that individuals who differ from their coworkers in age, sex, or racioethnicity would feel threatened by their outnumbered status and subsequently motivated to be absent, tardy, or more likely to turnover. However, we expected coworker withdrawal behavior to moderate whether or not dissimilar personnel act on these desires. Results from hierarchical multilevel modeling analyses of data from 470 U.S. call center workers nested in 51 work groups revealed that racioethnic dissimilarity was positively related to time‐lagged changes in absenteeism and tardiness as well as heightened turnover likelihood. These effects emerged only among employees whose coworkers engaged in greater withdrawal behavior. Importantly, racioethnically dissimilar employees working in more permissive climates (i.e., those with high levels of coworker absenteeism, tardiness, or turnover) exhibited the greatest increases in absenteeism and tardiness over three months and had the highest supervisor‐rated turnover likelihood. Implications for diversity management are discussed. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
97.
98.
A Modeling System to Assess Land Cover Land Use Change Effects on SAV Habitat in the Mobile Bay Estuary
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Maurice G. Estes Jr. Mohammad Z. Al‐Hamdan Jean T. Ellis Chaeli Judd Dana Woodruff Ronald M. Thom Dale Quattrochi Brian Watson Hugo Rodriguez Hoyt Johnson III Tom Herder 《Journal of the American Water Resources Association》2015,51(2):513-536
Estuarine ecosystems are largely influenced by watersheds directly connected to them. In the Mobile Bay, Alabama watersheds we examined the effect of land cover and land use (LCLU) changes on discharge rate, water properties, and submerged aquatic vegetation, including freshwater macrophytes and seagrasses, throughout the estuary. LCLU scenarios from 1948, 1992, 2001, and 2030 were used to influence watershed and hydrodynamic models and evaluate the impact of LCLU change on shallow aquatic ecosystems. Overall, our modeling results found that LCLU changes increased freshwater flows into Mobile Bay altering temperature, salinity, and total suspended sediments (TSS). Increased urban land uses coupled with decreased agricultural/pasture lands reduced TSS in the water column. However, increased urbanization or agricultural/pasture land coupled with decreased forest land resulted in higher TSS concentrations. Higher sediment loads were usually strongly correlated with higher TSS levels, except in areas where a large extent of wetlands retained sediment discharged during rainfall events. The modeling results indicated improved water clarity in the shallow aquatic regions of Mississippi Sound and degraded water clarity in the Wolf Bay estuary. This integrated modeling approach will provide new knowledge and tools for coastal resource managers to manage shallow aquatic habitats that provide critical ecosystem services. 相似文献
99.
Impact of payments for environmental services and protected areas on local livelihoods and forest conservation in northern Cambodia 总被引:1,自引:0,他引:1
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The potential impacts of payments for environmental services (PES) and protected areas (PAs) on environmental outcomes and local livelihoods in developing countries are contentious and have been widely debated. The available evidence is sparse, with few rigorous evaluations of the environmental and social impacts of PAs and particularly of PES. We measured the impacts on forests and human well‐being of three different PES programs instituted within two PAs in northern Cambodia, using a panel of intervention villages and matched controls. Both PES and PAs delivered additional environmental outcomes relative to the counterfactual: reducing deforestation rates significantly relative to controls. PAs increased security of access to land and forest resources for local households, benefiting forest resource users but restricting households’ ability to expand and diversify their agriculture. The impacts of PES on household well‐being were related to the magnitude of the payments provided. The two higher paying market‐linked PES programs had significant positive impacts, whereas a lower paying program that targeted biodiversity protection had no detectable effect on livelihoods, despite its positive environmental outcomes. Households that signed up for the higher paying PES programs, however, typically needed more capital assets; hence, they were less poor and more food secure than other villagers. Therefore, whereas the impacts of PAs on household well‐being were limited overall and varied between livelihood strategies, the PES programs had significant positive impacts on livelihoods for those that could afford to participate. Our results are consistent with theories that PES, when designed appropriately, can be a powerful new tool for delivering conservation goals whilst benefiting local people. 相似文献
100.
Aleix Serrat‐Capdevila Juan B. Valdes Eugene Z. Stakhiv 《Journal of the American Water Resources Association》2014,50(2):509-525
This article is an assessment of the current state of the art and relative utility of satellite precipitation products (SPPs) for hydrologic applications to support water management decisions. We present a review of SPPs, their accuracy in diverse settings including the influence of geography, topography, and weather systems, as well as the pros and cons of their use for different water management applications. At the end of this broad synthesizing effort, recommendations are proposed for: (1) SPP developers to improve the quality, usability, and relevance of precipitation products; and (2) SPP users to improve the reliability of their predictions and hydrologic applications to better support water management. 相似文献