Plant growth rates and seed size: a re-evaluation

Small-seeded plant species are often reported to have high relative growth rate or RGR. However, because RGR declines as plants grow larger, small-seeded species could achieve higher RGR simply by virtue of their small size. In contrast, size-standardized growth rate or SGR factors out these size effects. Differences in SGR can thus only be due to differences in morphology, allocation, or physiology. We used nonlinear regression to calculate SGR for comparison with RGR for 10 groups of species spanning a wide range of life forms. We found that RGR was negatively correlated with seed mass in nearly all groups, but the relationship between SGR and seed mass was highly variable. We conclude that small-seeded species only sometimes possess additional adaptations for rapid growth over and above their general size advantage.     

Predicting the form and direction of work role performance from the Big 5 model of personality traits

This research examined the prediction of the form and direction of work role performance from the Big 5 model of personality traits. Nine dimensions of work role performance are created by cross‐classifying the form of work role behavior (proficient, adaptive, and proactive) with the level at which that behavior contributes to effectiveness (individual, team, and organizational). The authors collected self‐report measurements of personality from 1447 government employees and supervisor ratings of performance. Openness to experience and agreeableness had opposing effects on individual proactivity – openness was positively related, whereas agreeableness was negatively related to this dimension. Openness to experience also had opposing effects on the form of work role performance – it was positively related to individual and organizational proactivity but negatively related to team and organizational proficiency. Conscientiousness was a stronger predictor of individual task proficiency than the remaining eight dimensions, whereas the reverse was true for neuroticism. Extraversion was negatively related to individual proficiency. Using a broad taxonomy of performance that incorporates a theoretical framework for distinguishing between constructs shows promise for identifying which personality traits are important for which aspects of work role performance. Copyright © 2011 John Wiley & Sons, Ltd.     

Pediatric pedestrian trauma study: a pilot project

OBJECTIVE: To evaluate the implementation of the WalkSafe Program, a school based educational injury prevention program for children grades Kindergarten through 5. METHODS: A randomized comparative design was used for this study. The study was conducted in two high-risk urban school districts, which were chosen based on the geographic areas with the highest pedestrian injury and fatality rates. Four elementary schools (two in each district) were identified as potential study sites. Two intervention schools, one in each school district, were randomly chosen to receive the WalkSafe program; the other two schools served as controls, and received no intervention. The data was collected within the classroom setting for both the intervention and control schools. All elementary school children were administered the same pedestrian safety questionnaire as a pre-test, post-test and at three months following the intervention. RESULTS: A total of 2300 children participated in the WalkSafe program. The intervention (I) schools showed significant improvement in post-test scores then the control (C) schools (p = 0.012), and the (I) schools were able to maintain their test scores as reflected in a three-month follow-up evaluation (p = 0.47). Grades 3-5 of the (I) schools showed significant improvement in their test scores over grades K-2 (p < 0.0001). CONCLUSION: The WalkSafe program was shown to improve the pedestrian safety knowledge of elementary school children. Future research will include implementing the WalkSafe program at each elementary school within a single high-risk district.