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Although our understanding of how animal personality affects fitness is incomplete, one general hypothesis is that personality traits (e.g. boldness and aggressiveness) contribute to competitive ability. If so, then under resource limitation, personality differences will generate variation in life history traits crucial to fitness, like growth. Here, we test this idea using data from same-sex dyadic interaction trials of sheepshead swordtails (Xiphophorus birchmanni). In males, there was evidence of repeatable variation across a suite of agonistic contest behaviours, while repeatable opponent effects on focal behaviour were also detected. A single vector explains 80 % of the among-individual variance in multivariate phenotype and can be viewed as aggressiveness. We also find that aggressiveness predicts dominance—the repeatable tendency to win food in competition—and dominant individuals show faster post-trial weight gain (independently of initial size). In females, a dominance hierarchy predictive of weight gain was also found, but there was no evidence of variation in aggressiveness. While size often predicts contest outcome, our results show that individuals may sometimes grow larger because they are behaviourally dominant rather than vice versa. When resources are limited, personality traits such as aggression can influence growth, life history, and fitness through impacts on resource acquisition.  相似文献   
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The administration of Jiuzhaigou National Park in Sichuan Province, China, is in the process of considering a range of upgrades to their sanitation and wastewater treatment systems. Their case history involves an ongoing series of engineering design flaws and management failures. The administration of the Park identified sustainability, environmental protection, and education goals for their sanitation and wastewater treatment system. To meet the goal of sustainability, environmental and economic concerns of the Park’s administration had to be balanced with socio-cultural needs. An advanced reconnaissance method was developed that identified reasons for previous failures, conducted stakeholder analysis and interviews, determined evaluation criteria, and introduced innovative alternatives with records of successful global implementations. This evaluation also helped the Park to better define their goals. To prevent future failures, the administration of the Park must commit to a balanced and thorough evaluation process for selection of a final alternative and institute effective long-term management and monitoring of systems. In addition, to meet goals and achieve energy efficient, cost-effective use of resources, the Park must shift their thinking from one of waste disposal to resource recovery. The method and criteria developed for this case study provides a framework to aid in the successful implementation of sanitation projects in both underdeveloped and developed areas of the world, incorporating socio-cultural values and resource recovery for a complex group of stakeholders.  相似文献   
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We conducted a survey of 3321 Forest Service employees involved in compliance with the National Environmental Policy Act (NEPA) followed by five focus groups to investigate agency views of the purpose of agency NEPA processes and their appropriate measures of success. Results suggest the lack of a unified critical task for Forest Service NEPA processes and that employees' functions relevant to NEPA influence their views of its meaning. Compared to other agency personnel, members of interdisciplinary teams who carry out most day-to-day NEPA-related tasks placed greater emphasis on minimizing negative environmental and social impacts, satisfying multiple stakeholders and avoiding litigation and appeals. Line officers, who typically serve as the decision makers following NEPA processes, placed greatest emphasis on efficient implementation and least emphasis on minimizing impacts. Advisory personnel placed greatest emphasis on effective disclosure of analyses and decision-making. We discuss the structural origins of these differences as well as their implications.  相似文献   
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A mass balance study was performed under controlled field conditions to investigate the phytoremediation of perchloroethylene (PCE) by hybrid poplar trees. Water containing 7–14 mg L?1 PCE was added to the test bed. Perchloroethylene, trichloroethylene, and cis-dichloroethylene were detected in the effluent at an average of 0.12 mg L?1, 3.9 mg L?1, and 1.9 mg L?1, respectively. The total mass of chlorinated ethenes in the water was reduced by 99%. Over 95% of the recovered chlorine was as free chloride in the soil, indicating near-complete dehalogenation of the PCE. Transpiration, volatilization, and accumulation in the trees were all found to be minor loss mechanisms. In contrast, 98% of PCE applied to an unplanted soil chamber was recovered as PCE in the effluent water or volatilized into the air. These results suggest that phytoremediation can be an effective method for treating PCE-contaminated groundwater in field applications.  相似文献   
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Flow direction reversal (FDR) was proposed as a novel method to increase net water production (NWP) during cross-flow ultrafiltration. The design of the pilot-plant study allowed measurement of specific flux recovery after each chemically assisted backwash (BW) combined with FDR and after each FDR at the midpoint of each BW/FDR cycle. The percent recovery of specific flux was higher following FDR (55%) than combined BW and FDR (53%) at lower chemical dosages; however, the percent increase in specific flux recovery by FDR was much lower (20%) when the chemical dose was doubled. A mathematical model was developed to predict the NWP achieved by any combination ofBW/ FDR and FDR frequency. For example, the advantage of introducing FDR was demonstrated at the lower chlorine dose, whereby the percent increase in NWP by alternating 15-minute intervals of BW/FDR with FDR over BW/ FDR alone was 10% for 30-minute BW/FDR intervals and 2% for 15-minute BW/FDR intervals.  相似文献   
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