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101.
A multilevel study of group‐focused and individual‐focused transformational leadership,social exchange relationships,and performance in teams 下载免费PDF全文
Using matched reports from 73 team leaders and 359 of their members across 23 companies in Korea, we examined a multilevel model where group‐ and individual‐focused transformational leadership and their influence processes operate at the team and dyadic levels independently and interactively to be associated with team and member performance. Results indicated that group‐focused transformational leadership was positively associated with team performance through team member exchange (TMX), whereas individual‐focused transformational leadership positively related to team members' in‐role and extra‐role performance through leader–member exchange (LMX). TMX not only positively mediated the relationships between group‐focused transformational leadership and member performance after controlling for LMX but also positively moderated LMX–performance relationships. Moreover, the indirect effect of individual‐focused transformational leadership through LMX on member performance was contingent upon the level of TMX. Theoretical and applied implications are discussed. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
102.
Juggling work and family responsibilities when involuntarily working more from home: A multiwave study of financial sales professionals 下载免费PDF全文
Laurent M. Lapierre Elianne F. van Steenbergen Maria C. W. Peeters Esther S. Kluwer 《组织行为杂志》2016,37(6):804-822
Using multiwave survey data collected among 251 financial sales professionals, we tested whether involuntarily working more from home (teleworking) was related to higher time‐based and strain‐based work‐to‐family conflict (WFC). Employees' boundary management strategy (integration vs. segmentation) and work–family balance self‐efficacy were considered as moderators of these relationships. Data were collected one month before, three months after, and 12 months after the implementation of a new cost‐saving policy that eliminated employees' access to office space in a centralized work location. The policy resulted in employees being forced to work more from home. A voluntary telework program had been in effect before the new policy, implying that working more from home as a result of the new policy was involuntary in nature. Results revealed that involuntarily working more from home was associated with higher strain‐based WFC but not higher time‐based WFC. However, moderator analyses revealed that the positive association between involuntarily working more from home and both types of WFC was significantly stronger among employees with weaker self‐efficacy in balancing work and family. Boundary management strategy had no detectable moderating effect. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
103.
Christiane Spitzmueller Zhuxi Wang Jing Zhang Candice L. Thomas Gwenith G. Fisher Russell A. Matthews Lane Strathearn 《组织行为杂志》2016,37(5):692-718
The American Academy of Pediatrics recommends that women breastfeed because of improved health outcomes for mothers and children. Because maternal employment during the first year of the child's life has been identified as a reason for breastfeeding cessation, we develop and test a role‐theory‐based framework to explain women's continuation of breastfeeding after return to work (Study 1) and report results of an exploratory study linking breastfeeding at work with job attitudes and well‐being (Study 2). Applying survival analysis to a longitudinal dataset gathered by the Centers for Disease Control (Study 1), we identify pregnant women's perceived employer support for breastfeeding as a predictor of women's breastfeeding goal intentions. Supervisors' negative workplace remarks about breastfeeding related to an eightfold increase of women's likelihood to discontinue exclusive breastfeeding and perceived support for breastfeeding after return to work predicted exclusive breastfeeding continuation. Results of Study 2 suggest that women who return to work and continue breastfeeding experience more family‐to‐work conflict and overload than women who do not reconcile work and breastfeeding. Further, results of Study 2 provide preliminary evidence suggesting that perceptions of supervisor and coworker support for breastfeeding relate positively to general perceptions of organizational support and negatively to depressive symptoms. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
104.
JONATHAN BART ROBERT M. PLATTE BRAD ANDRES STEPHEN BROWN JAMES A. JOHNSON WILLIAM LARNED 《Conservation biology》2013,27(6):1304-1312
We used data from aerial surveys (1992–2010) of >100,000 km2 and ground surveys (1998–2004) of >150 km2 to estimate the density and abundance of birds on the North Slope of Alaska (U.S.A.). In the ground surveys, we used double sampling to estimate detection ratios. We used the aerial survey data to compare densities of birds and Arctic fox (Vulpes lagopus), the major nest predator of birds, on the North Slope, in Prudhoe Bay, and in nearby areas. We partitioned the Prudhoe Bay oil field into 2 × 2 km plots and determined the relation between density of aquatic birds and density of roads, buildings, and other infrastructure in these plots. Abundance and density (birds per square kilometer) of 3 groups of aquatic birds—waterfowl, loons, and grebes; shorebirds; and gulls, terns, and jaegers—were highest in the National Petroleum Reserve–Alaska (NPRA) and lowest in the Arctic National Wildlife Refuge. Six other major wetlands occur in the Arctic regions of Canada and Russia, but the largest population of aquatic birds was in the NPRA. Aquatic birds were concentrated in the northern part of the NPRA. For example, an area that covered 18% of the NPRA included 53% of its aquatic birds. The aerial surveys showed that bird density was not lower and fox density was not higher in Prudhoe Bay than in surrounding areas. Density of infrastructure did not significantly affect bird density for any group of species. Our results establish that the NPRA is one of the most important areas for aquatic birds in the Arctic. Our results and those of others also indicate that oil production, as practiced in Prudhoe Bay, does not necessarily lead to substantial declines in bird density or productivity in or near the developed areas. Prioridades para la Conservación de Aves en el Norte de Alaska 相似文献
105.
Understanding individual attitudes and how these predict overt opposition to predator conservation or direct, covert action against predators will help to recover and maintain them. Studies of attitudes toward wild animals rely primarily on samples of individuals at a single time point. We examined longitudinal change in individuals’ attitudes toward gray wolves (Canis lupus). In the contiguous United States, amidst persistent controversy and opposition, abundances of gray wolves are at their highest in 60 years. We used mailed surveys to sample 1892 residents of Wisconsin in 2001 or 2004 and then resampled 656 of these individuals who resided in wolf range in 2009. Our study spanned a period of policy shifts and increasing wolf abundance. Over time, the 656 respondents increased agreement with statements reflecting fear of wolves, the belief that wolves compete with hunters for deer (Odocoileus virginianus), and inclination to poach a wolf. Endorsement of lethal control of wolves by the state and public hunting of wolves also increased. Neither the time span over which respondents reported exposure to wolves locally nor self‐reported losses of domestic animals to wolves correlated with changes in attitude. We predict future increases in legal and illegal killing of wolves that may reduce their abundance in Wisconsin unless interventions are implemented to improve attitudes and behavior toward wolves. To assess whether interventions change attitudes, longitudinal studies like ours are needed. Análisis Longitudinal de las Actitudes Hacia Lobos 相似文献
106.
Substituted urea compounds are well-known as potent inhibitors of juvenile hormone epoxide hydrolase (JHEH) of the tobacco hornworm Manduca sexta. Docking simulations of 47 derivatives inside JHEH were performed to gain insight into the structural characteristics of these complexes. The obtained orientations show a strong similitude with the observed in the known X-ray crystal structures of human soluble epoxide hydrolase (sEH) complexed with dialkylurea inhibitors. In addition, the predicted inhibitor concentration (IC50) of the above-mentioned compounds as JHEH inhibitors were obtained by a quantitative structure-activity relationship (QSAR) method by using comparative molecular field analysis (CoMFA) applied to aligned dataset. The best models included steric and electrostatic fields and had adequate predictive abilities. In addition, these models were used to predict the activity of an external test set of compounds that was not used for building the model. Furthermore, plots of the CoMFA fields allowed conclusions to be drawn for the choice of suitable inhibitors. 相似文献
107.
Single- and dual-porosity modelling of flow in reclaimed mine soil cores with embedded lignitic fragments 总被引:1,自引:0,他引:1
Lignitic mine soils represent a typical two-scale dual-porosity medium consisting of a technogenic mixture of overburden sediments that include lignitic components as dust and as porous fragments embedded within a mostly coarse-textured matrix. Flow and transport processes in such soils are not sufficiently understood to predict the course of soil reclamation or of mine drainage. The objective of this contribution is to identify the most appropriate conceptual model for describing small-scale heterogeneity effects on flow on the basis of the physical structure of the system. Multistep flow experiments on soil cores are analyzed using either mobile2013;immobile or mobile2013;mobile type 1D dual-porosity models, and a 3D numerical model that considers a local-scale distribution of fragments. Simulations are compared with time series' of upward infiltration and matric potential heads measured at two depths using miniature tensiometers. The 3D and the 1D dual-permeability models yielded comparable results as long as pressure heads are in local equilibrium; however, could describe either the upward infiltration or the matric potential curves but not both at the same time. The mobile2013;immobile type dual-porosity model failed to describe the data. A simultaneous match with pressure heads and upward infiltration data could only be obtained with the 1D dual-permeability model (i.e., mobile2013;mobile) by assuming an additional restriction of the inter-domain water transfer. These results indicate that for unsaturated flow conditions at higher matric potential heads (i.e., here >− 40 hPa), water in a restricted part of the fragment domain must be more mobile as compared to water in the sandy matrix domain. Closer inspections of the pore system and first neutron radiographic imaging support the hypothesis that a more continuous pore region exists at these pressure heads in the vicinity of the lignitic fragments possibly formed by fragment contacts and a lignitic dust interface-region between the two domains. The results suggest that the small-scale structure is too complex as to be represented by weighted contributions of individual components alone. 相似文献
108.
Numerical Investigation of Boundary-Layer Evolution and Nocturnal Low-Level Jets: Local versus Non-Local PBL Schemes 总被引:3,自引:0,他引:3
Kesu Zhang Huiting Mao Kevin Civerolo Stephen Berman Jia-Yeong Ku S. Trivikrama Rao Bruce Doddridge C. Russell Philbrick Richard Clark 《Environmental Fluid Mechanics》2001,1(2):171-208
Numerical simulations of the evolution of the planetary boundary layer (PBL) and nocturnal low-level jets (LLJ) have been carried out using MM5 (version 3.3) with four-dimensional data assimilation (FDDA) for a high pollution episode in the northeastern United States during July 152013;20, 1999. In this paper, we assess the impact of different parameterizations on the PBL evolution with two schemes: the Blackadar PBL, a hybrid local (stable regime) and non-local (convective regime) mixing scheme; and the Gayno2013;Seaman PBL, a turbulent kinetic energy (TKE)-based eddy diffusion scheme. No FDDA was applied within the PBL to evaluate the ability of the two schemes to reproduce the PBL structure and its temporal variation. The restriction of the application of FDDA to the atmosphere above the PBL or the lowest 8 model levels, whichever is higher, has significantly improved the predicted strength and timing of the LLJ during the night. A systematic analysis of the PBL evolution has been performed for the primary meteorological fields (temperature, specific humidity, horizontal winds) and for the derived parameters such as the PBL height, virtual potential temperature, relative humidity, and cloud cover fraction. There are substantial differences between the PBL structures and evolutions simulated by these two different schemes. The model results were compared with independent observations (that were not used in FDDA) measured by aircraft, RASS and wind profiler, lidar, and tethered balloon platforms during the summer of 1999 as part of the NorthEast Oxidant and Particle Study (NE-OPS). The observations tend to support the non-local mixing mechanism better than the layer-to-layer eddy diffusion in the convective PBL. 相似文献
109.
JUKKA SUHONEN MILLA HILLI‐LUKKARINEN ESA KORKEAMÄKI MARKKU KUITUNEN JOHANNA KULLAS JOUNI PENTTINEN JUKKA SALMELA 《Conservation biology》2010,24(4):1148-1153
Abstract: Understanding the risk of extinction of a single population is an important problem in both theoretical and applied ecology. Local extinction risk depends on several factors, including population size, demographic or environmental stochasticity, natural catastrophe, or the loss of genetic diversity. The probability of local extinction may also be higher in low‐quality sink habitats than in high‐quality source habitats. We tested this hypothesis by comparing local extinction rates of 15 species of Odonata (dragonflies and damselflies) between 1930–1975 and 1995–2003 in central Finland. Local extinction rates were higher in low‐quality than in high‐quality habitats. Nevertheless, for the three most common species there were no differences in extinction rates between low‐ and high‐quality habitats. Our results suggest that a good understanding of habitat quality is crucial for the conservation of species in heterogeneous landscapes. 相似文献
110.
The debate on diversity2013;stability relationships has a long history of theoretical interest and plays a central role in development of modern ecology. But such debate has recently re-opened under critical scrutiny both in theoretical and empirical studies. In this paper we use allometric (or energetic) scaling and statistical physics approaches to this problem. On the basis of local Damuth symmetry, a Markov model of transfer of energy between different species, and the fluctuation2013;dissipation theorem, scaling rules of species number and population variability of biological communities near equilibrium are derived. These scaling rules indicate that the diversity2013;stability relationship may be an energetic and thermodynamic consequence of ecological systems near equilibrium, not a simple statistical consequence as derived by other recent theoretical work. 相似文献