Edaphic influences on plant community adaptation in the Chiquibul forest of Belize

Edaphic variables figure significantly in plant community adaptations in tropical ecosystems but are often difficult to resolve because of the confounding influence of climate. Within the Chiquibul forest of Belize, large areas of Ultisols and Inceptisols occur juxtaposed within a larger zone of similar climate, permitting unambiguous assessment of edaphic contributions to forest composition. Wet chemical analyses, X-ray diffraction and X-ray fluorescence spectroscopy were employed to derive chemical (pH, exchangeable cations, CEC, total and organic C, total trace elements) and physical (texture, mineralogy) properties of four granite-derived Ustults from the Mountain Pine Ridge plateau and four limestone-derived Ustepts from the San Pastor region. The soils of these two regions support two distinct forests, each possessing a species composition reflecting the many contrasting physicochemical properties of the underlying soil. Within the Mountain Pine Ridge forest, species abundance and diversity is constrained by nutrient deficiencies and water-holding limitations imposed by the coarse textured, highly weathered Ultisols. As a consequence, the forest is highly adapted to seasonal drought, frequent fires and the significant input of atmospherically derived nutrients. The nutrient-rich Inceptisols of the San Pastor region, conversely, support an abundant and diverse evergreen forest, dominated by Sabal mauritiiformis, Cryosophila stauracantha and Manilkara spp. Moreover, the deep, fine textured soils in the depressions of the karstic San Pastor landscape collect and retain during the wet season much available water, thereby serving as refugia during particularly long periods of severe drought. To the extent that the soils of the Chiquibul region promote and maintain forest diversity, they also confer redundancy and resilience to these same forests and, to the broader ecosystem, of which they are a central part. (C) 2005 Elsevier B.V. All rights reserved.

Worry and problem-solving skills and beliefs in primary school children

Objective. To examine the association between worry and problem-solving skills and beliefs (confidence and perceived control) in primary school children. Method. Children (8–11 years) were screened using the Penn State Worry Questionnaire for Children. High (N ¼ 27) and low (N ¼ 30) scorers completed measures of anxiety, problem-solving skills (generating alternative solutions to problems, planfulness, and effectiveness of solutions) and problem-solving beliefs(confidence and perceived control). Results. High and low worry groups differed significantly on measures of anxiety and problem-solving beliefs (confidence and control) but not on problem-solving skills. Conclusions. Consistent with findings with adults, worry in children was associated with cognitive distortions, not skills deficits. Interventions for worried children may benefit froma focus on increasing positive problem-solving beliefs.

Measuring the value of “all play and no work”: can rigorous assessment of simulation games drive innovative teaching in construction?

The construction field is dynamic and dominated by complex, ill-defined problems for which myriad possible solutions exist. Teaching students to solve construction-related problems requires an understanding of the nature of these complex problems as well as the implementation of effective instructional strategies to address them. Traditional approaches to teaching construction planning and management have long been criticized for presenting students primarily with well-defined problems - an approach inconsistent with the challenges encountered in the industry. However, growing evidence suggests that employing innovative teaching approaches, such as interactive simulation games, offers more active, hands-on and problem-based learning opportunities for students to synthesize and test acquired knowledge more closely aligned with real-life construction scenarios. Simulation games have demonstrated educational value in increasing student problem solving skills and motivation through critical attributes such as interaction and feedback-supported active learning. Nevertheless, broad acceptance of simulation games in construction engineering education remains limited. While recognizing benefits, research focused on the role of simulation games in educational settings lacks a unified approach to developing, implementing and evaluating these games. To address this gap, this paper provides an overview of the challenges associated with evaluating the effectiveness of simulation games in construction education that still impede their wide adoption. An overview of the current status, as well as the results from recently implemented Virtual Construction Simulator (VCS) game at Penn State provide lessons learned, and are intended to guide future efforts in developing interactive simulation games to reach their full potential.