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排序方式: 共有107条查询结果,搜索用时 234 毫秒
81.
Thriving at work is a positive psychological state characterized jointly by learning and vitality. Conventional wisdom and some initial research indicate that such thriving benefits both employees themselves and their organizations. This study specifically tests thriving at work by linking it to a theoretically important personal outcome variable (self‐development), refining its relationship with agentic work behaviors (task focus and heedful relating), and proposing and testing two new antecedent variables (psychological capital and supervisor support climate). Using structural equation modeling on a sample of 198 dyads (employees and their supervisors), strong support was found for the theory‐driven hypothesized relationships. The results contribute to a better understanding of positive organizational scholarship and behavior in general and specifically to the recently emerging positive construct of employees' thriving at work. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
82.
Ted L. Napier 《Journal of the American Water Resources Association》2000,36(4):723-735
ABSTRACT: Data were collected in the fall of 1998 and the winter of 1999 from 1,011 land owner‐operators within three watersheds in the North Central Region of the United States to assess adoption of soil and water protection practices. Farm owner‐operators were asked to indicate how frequently they used 18 different agricultural production practices. Many farmers within the three watersheds had adopted conservation protection practices. However, they also employed production practices that could negate many of the environmental benefits associated with conservation practices in use. Comparison of adoption behaviors used in the three watersheds revealed significant differences among the study groups. Respondents in the Iowa and Ohio watersheds reported greater use of conservation production systems than did farmers in Minnesota. However, there were no significant differences between Ohio and Iowa farmers in terms of use of conservation production practices. This was surprising, since farmers in the Ohio watershed had received massive amounts of public and private investments to motivate them to adopt and to continue using conservation production systems. These findings bring into serious question the use of traditional voluntary conservation programs such as those employed in the Ohio watershed. Study findings suggest that new policy approaches should be considered. It is argued that “whole farm planning” should be a significant component of new agricultural conservation policy. 相似文献
83.
Franke Alastair Falk Knud Hawkshaw Kevin Ambrose Skip Anderson David L. Bente Peter J. Booms Travis Burnham Kurt K. Ekenstedt Johan Fufachev Ivan Ganusevich Sergey Johansen Kenneth Johnson Jeff A. Kharitonov Sergey Koskimies Pertti Kulikova Olga Lindberg Peter Lindström Berth-Ove Mattox William G. McIntyre Carol L. Mechnikova Svetlana Mossop Dave Møller Søren Nielsen Ólafur K. Ollila Tuomo Østlyngen Arve Pokrovsky Ivan Poole Kim Restani Marco Robinson Bryce W. Rosenfield Robert Sokolov Aleksandr Sokolov Vasiliy Swem Ted Vorkamp Katrin 《Ambio》2020,49(3):762-783
Ambio - The peregrine falcon (Falco peregrinus) and the gyrfalcon (Falco rusticolus) are top avian predators of Arctic ecosystems. Although existing monitoring efforts are well established for both... 相似文献
84.
Sue Kimbrough Ted Palma Richard W. Baldauf 《Journal of the Air & Waste Management Association (1995)》2014,64(3):349-359
Exposures to mobile source air toxics (MSATs) have been associated with numerous adverse health effects. While thousands of air toxic compounds are emitted from mobile sources, members of a subset of compounds are considered high priority due to their significant contribution to cancer and noncancer health risks and the contribution of mobile sources to total exposure as evaluated by the U.S. Environmental Protection Agency (EPA) National-Scale Air Toxics Assessments (NATA). These pollutants include benzene, 1,3-butadiene, ethylbenzene, acrolein, acetaldehyde, formaldehyde, naphthalene, polycyclic organic matter, and diesel particulate matter/organic gases. This study provided year-long trends of benzene, 1,3-butadiene, acrolein, acetaldehyde, and formaldehyde in Las Vegas, NV. Results indicated that MSAT concentrations often did not exhibit trends typical of other primary emitted pollutants in this study. Instead, other mobile sources beyond the highway of interest contributed to the measured values, including a major arterial road, a large commercial airport, and a nearby parking lot. The data were compared with relevant census-tract NATA estimates, with estimated ambient 1,3-butadiene concentrations similar to the measured values. Measured benzene values were much lower relative to the NATA total ambient benzene concentrations. Measured acrolein values were much higher relative to the NATA total acrolein concentrations. Measured acetaldehyde and formaldehyde values were also higher relative to the NATA total acetaldehyde and formaldehyde concentrations for all wind conditions and downwind conditions. Some possible explanations for these differences include nearby sources influencing the measured values; meteorological influences that may not be well captured by the NATA modeling regime; chemical reactivity of measured compounds; and additional explanatory variables may be needed for certain urban areas in order to accurately disaggregate anthropogenic air toxics emissions.
Implications: Comparison of air toxics concentrations measured at four long-term near-road sites in Las Vegas, NV, show generally good agreement with the EPA 2005 NATA total ambient concentrations. Measured concentrations did not compare as well with EPA 2005 NATA for the on-road mobile portion of the ambient concentrations. This highlights the complexity of air toxic emission sources and impacts in urban areas, especially around large highway facilities; NATA's inability to capture local-scale meteorology and fine-scale ambient gradients; and that additional explanatory variables may be needed for certain urban areas in order to accurately disaggregate anthropogenic air toxics emissions. 相似文献
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88.
Index of Alien Impact: A Method for Evaluating Potential Ecological Impact of Alien Plant Species 总被引:1,自引:0,他引:1
Teresa K. Magee Paul L. Ringold Michael A. Bollman Ted L. Ernst 《Environmental management》2010,45(4):759-778
Alien plant species are stressors to ecosystems and indicators of reduced ecosystem integrity. The magnitude of the stress
reflects not only the quantity of aliens present, but also the quality of their interactions with native ecosystems. We develop
an Index of Alien Impact (IAI) to estimate the collective ecological impact of in situ alien species. IAI summarizes the frequency of occurrence and potential
ecological impact (Invasiveness-Impact Score (I
i
)) of individual alien species for all aliens present in a particular location or community type. A component metric, I
i
, is based on ecological species traits (life history, ecological amplitude, and ability to alter ecosystem processes) that
reflect mechanisms, which can increase impact to ecosystem structure and function. While I
i
is less complex than some other multi-metric rankings of alien impact, it compares well to these metrics and to qualitative
judgments. IAI can be adapted for different ecological settings by modifying the set of species traits incorporated in I
i
to reflect properties likely to breach biotic and abiotic barriers or alter ecosystem function in a particular region or
community type of interest. To demonstrate our approach, we created versions of IAI and I
i
, applicable to the diverse streamside vegetation of a river basin (19,631 km2) spanning low-elevation arid to mesic montane habitats in eastern Oregon, USA. In this demonstration effort, we (1) evaluate
relationships of IAI to metrics describing invasion level, and (2) illustrate the potential utility of IAI for prioritizing
alien species management activities and informing restoration goals. 相似文献
89.
90.
J. Michael Reed Jeffrey R. Walters Ted E. Emigh D. Erran Seaman 《Conservation biology》1993,7(2):302-308
Loss of genetic variability in isolated populations is an important issue for conservation biology. Most studies involve only a single population of a given species and a single method of estimating rate of loss. Here we present analyses for three different Red-cockaded Woodpecker ( Picoides borealis ) populations from different geographic regions. We compare two different models for estimating the expected rate of loss of genetic variability, and test their sensitivity to model parameters. We found that the simpler model (Reed et al. 1988) consistently estimated a greater rate of loss of genetic variability from a population than did the Emigh and Pollak (1979) model. The ratio of effective population size (which describes the expected rate of loss of genetic variability) to breeder population size varied widely among Red-cockaded Woodpecker populations due to geographic variation in demography. For this species, estimates of effective size were extremely sensitive to survival parameters, but not to the probability of breeding or reproductive success. Sensitivity was sufficient that error in estimating survival rates in the field could easily mask true population differences in effective size. Our results indicate that accurate and precise demographic data are prerequisites to determining effective population size for this species using genetic models, and that a single estimate of rate of loss of genetic variability is not valid across populations. 相似文献