Quantifying physical activity in first-through fourth-grade physical education via pedometry

The aim of this study was to determine pedometry steps per minute (SPM) cutscores that accurately quantify physical activity (PA) time in first- through fourth-grade physical education. A total of 257 participants were grouped in two data pools, first- and second-grade (n = 126), and third- and fourth-grade (n = 131). Systematic observation was the PA criterion instrument and pedometry was the predictor instrument. Correlations between physical activity measures were strong (r = .82-.89, p < .01). Ten min of PA and 33.33% of the lesson time engaged in PA within a 30-min class can be quantified by 61-63 SPM for first- and second-grade, and 58-61 SPM for third- and fourth-grade. IN CONCOLUSION: (a) SPM values were a valid indicator of students achieving or not achieving PA criteria, and (b) pedometry is a valid and practical tool for physical activity surveillance within physical education.     

Grand missions of agricultural innovation

This paper discusses three related examples of mission-oriented agricultural institutional innovations associated with substantial crop yield increases in the 20th century. It begins with the implementation of the United States Land-Grant System and then discusses in turn the planning and implementation of the two grand missions that led successively to the yield increases in wheat and rice that heralded the onset of the “Green Revolution.” It notes the remarkable role of the Rockefeller Foundation in identifying these two missions, and selecting personnel developed within the land-grant system to execute them with remarkable effectiveness.     

Stability, change, and correlates of the peer relationships of young children with mild developmental delays

The peer relationships of young children with mild developmental (cognitive) delays recruited at 4-6 years of age were examined in a longitudinal study across a 2-year period. Results revealed only modest increases in children's peer interactions, a high degree of intraindividual stability, and the existence of a poorly organized and conflict-prone pattern of peer interactions. Child cognitive and language levels as well as family stress and support were associated with children's peer interactions. A subgroup was identified of initially low interactors who were at especially high risk for future peer interaction problems. These findings further underscore the importance of designing and implementing early intervention programs in the area of peer relationships for children with mild developmental delays.