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Nine hectares (23 acres) of a degraded section of Patuxent Research Refuge in Laurel, Maryland, USA, were converted to wetland habitat by the Baltimore Gas and Electric Company in 1994. The wetlands were created as mitigation for 5.7 ha (14 acres) of wetlands that were impacted as part of the construction of an 8.5-km (5.3-mile) 500-kV overhead transmission line on the refuge. The area consists of a created forested wetland of 5.5 ha (13.5 acres), a seasonally inundated green-tree reservoir of 7.6 ha (6.5 acres), and an impounded pond wetland of 1.2 ha (3 acres). Construction included the planting of 6131 trees, 4276 shrubs, and 15,102 emergent plants. Part of the site has been studied intensively since completion and survival of trees and shrubs after two years was 88%. Measurements of these transplants have shown growth greater than on other created sites in Maryland. Grasses and other herbaceous vegetation were dominant plants in the meter-square plots in the first two years of sampling of the created forested wetland. Wildlife surveys for birds, mammals, amphibians, and reptiles have revealed diverse communities. Although these communities represent species consistent with open habitat, more typical forest species should colonize the area as it undergoes succession into a more mature forested wetland. The creation, management, and research of this mitigation site represents an excellent example of a partnership between a private electric power company and a federal wildlife refuge. This partnership has increased local biodiversity and improved regional water quality of the Patuxent River and the Chesapeake Bay. 相似文献
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Josiah Akinsanmi Gregory M. Perry 《Journal of the American Water Resources Association》2002,38(1):101-110
ABSTRACT: Traditional focus on reducing one environmental externality may cause another externality to increase. This article examines the environmental and economic costs of abating soil loss and (or) nitrate leaching through alternative optimal production systems in the nonirrigated farming systems of Northeastern Oregon. Models estimating soil loss and nitrate‐nitrogen leaching rates associated with current production processes, are linked to a Multi‐Objective Programming (MOP) model. The results show that site specific conditions influence the level of abatement expenditures and optimal production strategies to reduce soil loss and leaching rates. Moreover, while existing production strategies are effective in reducing soil loss at little cost, no strategies could be identified to reduce nitrate leaching rate on some soils. 相似文献
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Relational demography research has emphasized a similarity–attraction paradigm in explaining employees' reactions to demographic differences from other organizational members. This study examined similarity–attraction (nondirectional age differences) and status incongruence (directional age differences) predictions of age difference effects. The nondirectional and directional differences between the age of a subordinate and the ages of his or her immediate and higher‐level supervisors were used to predict employee absenteeism, citizenship, and work change behaviors. Results revealed that there were more significant and marginally significant directional age difference effects than nondirectional age difference effects on work outcomes. The implications of these results for organizations are discussed. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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This research explored ironic evaluation processes initiated by suppression instructions conveyed during diversity training. Raters watched one of three training videos: a video providing information about age diversity and recommending that they try to suppress age‐related thoughts; a video providing information about age, sex, race, and ethnic diversity and recommending that they try to suppress demography‐related thoughts; or a control video containing no suppression recommendations. All raters then evaluated a series of job applicants. During the evaluation task, some raters were cognitively busy while others were not. Ironically, busy raters instructed to suppress age‐related thoughts evaluated an older applicant less favorably than raters in other conditions. These results suggest that organizational diversity training including instructions to suppress stereotypic thoughts may have detrimental effects on evaluations of non‐traditional job applicants if raters are cognitively busy when they implement these instructions. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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Portable ladder assessment tool development and validation – Quantifying best practices in the field
Many causes for falls from ladders in construction are related to the user’s activities; however, the extent to which users comply with ladder use best practices is unknown and has not been well quantified before. We developed and tested an audit tool that assesses compliance with best practices guidelines for portable-ladder-use designed for applications in the construction industry. Implemented on a hand-held computer, the assessment tool consisted of a series of check-lists categorized in four groups; ladder condition, setup, moving on a ladder, and completing tasks from a ladder. For these four observational categories, the resulting tool contained 31 and 33 questions for step and extension ladders, respectively. Three individuals trained to use the tool scored a set of photographs and videos depicting 25 ladder conditions, 20 ladder setups, 10 users moving on ladders, and 13 users completing tasks from a ladder for a total of 78 observations. The assessment tool had good agreement across and within raters. For the three raters, agreement ranged from 79% to 97% across the questions. Within one subject, kappa coefficients for the intra-rater reliability ranged from 0.67 to 0.91. The tool offers a practical method to quantify best practices associated with ladder use that can ultimately inform targeted intervention efforts. 相似文献
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Perry J. Samson Garry Neighmond Andrew J. Yencha 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1232-1237
Linear regression of high volume air sampler data and various meteorological parameters was used to determine a suspended particulate air pollution climatology for Albany, NY. A new method for exhibiting associations between wind direction and pollutant levels using correlation coefficients is presented. Correlations between wind direction distribution frequency and other meteorological parameters is employed to help explain differences in correlations for direction with suspended particulate levels. Results show that high particulate concentrations correlate well with southerly wind flow throughout the study area, regardless of relative location of receptor to local sources. This suggests that ambient background concentrations inherent in different air masses more consistently affected suspended particulate levels than did the diffusion from local sources during the study period. Maximum particulate advection occurs under conditions of good mixing of the boundary layer and moderate wind speeds and is enhanced further in the absence of removal processes such as rainout and washout. Trajectory analysis of selected days indicates a definite relationship between path and origin of the wind flow and regional average particulate concentration. 相似文献
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