Predicting adolescent truancy: The importance of distinguishing between different aspects of instructional quality

Little is known about the association of classroom characteristics with adolescent truancy. A critical question is whether high achievement standards, high workload, and fast pace protect against or increase adolescent truancy. In this study, self-reports from 3491 Swiss grade 7, grade 8 and grade 9 students in 202 classes were used to predict truancy. Multilevel modeling was used to differentiate between the student and the class levels. High achievement standards were associated with a lower truancy rate at both the student and the class level, whereas fast instructional pace was associated with more truancy at both levels. A perception of the workload as being too low was an additional predictor of high truancy at both the student and the class level.     

未来气候变化对鄱阳湖区土地利用变化的影响评估

为了评估未来气候变化可能对鄱阳湖区土地利用变化产生的影响,本文根据IPCC的建议,利用新近建立的基于主体的土地利用变化模拟模型,详细分析了4种气候变化情景下鄱阳湖区1985-2035年的土地利用变化过程。这4种气候变化情景分别为A1B(经济高速增长模式)、A2(区域经济多样化增长模式)、B1(引进更多清洁能源的经济增长模式)和情景4(无气候变化模式)。在这些气候变化情景中,由于耕地的农业生产潜力差异显著,农户主体的收入和他们对土地利用方式的决策也发生了相应的改变。通过对这一过程的模拟和结果分析,发现气候变化可能有利于鄱阳湖区土地利用变化向着环境友好的方向自我调整。与A1B和A2两种气候变化情景相比,B1情景对土地利用变化的影响更具环境友好性。