Schedule-induced behavior in rats: Pellets versus powder

Food-deprived rats develop polydipsia on an intermittent schedule (fixed time 60 sec) of food pellet delivery, but not on an identical schedule of food powder delivery. This result was demonstrated with separate groups receiving each type of food and was replicated using rats as their own controls. Powdered food not only prevented the development of polydipsia, but it abruptly terminated ongoing polydipsia in rats that were switched from the scheduled delivery of pellets to powder. Ethological analysis of the behavior showed that the rats receiving powder were not engaging excessively in some behavior other than drinking. After discounting several factors, we concluded that the amount of oral activity associated with feeding, which occurred immediately after food delivery, was reciprocally related to the level of drinking.     

Emergency knowledge management and social media technologies: A case study of the 2010 Haitian earthquake

The US response to the 2010 Haiti Earthquake was a large effort coordinated by three major agencies that worked in tandem with the Government of Haiti, the United Nations, and many countries from around the globe. Managing this response effort was a complex undertaking that relied extensively on knowledge management systems (KMS). For the first time, however, US government agencies employed social media technologies such as wikis and collaborative workspaces as the main knowledge sharing mechanisms. In this research we present a case study developed through action research of how these social media technologies were used, what influences they made on knowledge sharing, reuse, and decision-making, and how knowledge was effectively (and at times ineffectively) maintained in these systems. First-hand knowledge of the response is used, offering strategies for future deployment of social media and important research questions that remain regarding social media as knowledge management systems, particularly for disaster and emergency management.     

Direct and indirect aggression during childhood and adolescence: a meta-analytic review of gender differences, intercorrelations, and relations to maladjustment

This meta-analytic review of 148 studies on child and adolescent direct and indirect aggression examined the magnitude of gender differences, intercorrelations between forms, and associations with maladjustment. Results confirmed prior findings of gender differences (favoring boys) in direct aggression and trivial gender differences in indirect aggression. Results also indicated a substantial intercorrelation (r = .76) between these forms. Despite this high intercorrelation, the 2 forms showed unique associations with maladjustment: Direct aggression is more strongly related to externalizing problems, poor peer relations, and low prosocial behavior, and indirect aggression is related to internalizing problems and higher prosocial behavior. Moderation of these effect sizes by method of assessment, age, gender, and several additional variables were systematically investigated.     

The Emotional Contours and Career Trajectories of (Disappointed) Reform Enthusiasts

Three individual cases, drawn from a larger body of case study data, illuminate a relatively unexamined aspect of teachers’ participation in large‐scale reform‐‐teachers’ experience of heightened emotionality and its relationship to career discontinuity or career risk. Disappointed reform enthusiasts point to three conditions that intensify emotional responses to reform and appear to result in career turning points: (1) the nature and extent of reform‐related conflict within salient work groups; (2) the degree of equilibrium among multiple sources of pressure and support; (3) institutional or administrative capacity to manage the pace, scale and dynamics of reform.     

Exploring the Associations Between Delayed School Entry and Achievement in Primary and Secondary School

This research investigated whether delayed school entry was associated with higher achievement in national tests of reading and numeracy in Grades 3, 5, 7, and 9 (n = 2,823). Delayed entry was related to advantages in reading (0.14 SD) and numeracy (0.08 SD) at Grade 3, although little variance was explained (1%–2%). This slight advantage persisted for both domains in Grades 5 and 7, albeit with smaller effects. In Grade 9 there was no association between delayed entry and either reading or numeracy. Exploratory analyses with subsamples in each grade (n = 424–667) revealed no associations between delayed entry and achievement after controlling for inattention and hyperactivity, and negative associations between inattention and achievement in all grades in both domains (−0.33, −0.49 SD).     

Economic globalisation,youth expectations and social class: The case of Sri Lanka

Whether economic globalisation is associated with a narrowing or a widening of the social class gap between the education and occupation expectations of Sri Lankan youth is examined through a test of four hypotheses. Methodologically, the study employs the estimated parameters from a system of seemingly unrelated equations for testing hypotheses. Youth expectations for education and occupation are higher than those of their parents when young. Social class effects vary among youth and fathers and mothers when young. The occupation expectations of youth show a widening gap between the middle and low social classes. In all other comparisons, the gaps are positive, indicating a widening, but none attains statistical significance. Causal explanations are explored and the implications for future investigations are identified.     

The biomechanics of situational baseball: Execution and perception of left-handed pitchers' simulated pick-off moves to first base

The aim of this study was to provide an in-depth analysis of the pick-off play in baseball. Ten collegiate left-handed pitchers and nine base-runners participated in this study. The pitchers were videotaped with four cameras to derive three-dimensional data while performing deliveries in the directions of first base and home plate in a laboratory setting. Deliveries were performed from flat ground. Differences between these deliveries were measured through ten selected joint and segment angles. The base-runners completed two distinct procedures in which they viewed video footage of left-handed pitchers and estimated the intended delivery direction. Base-runners were subsequently interviewed to determine the reasoning behind their decisions. The pitchers' data revealed differences between delivery types in nearly all of the selected angles (P < 0.01). The base-runners' data demonstrated that their ability to discriminate delivery types improved when allowed more viewing time per trial (P < 0.01). Additionally, commonalities exist among the base-runners' focal points on the pitcher while making decisions regarding delivery direction and the kinematic differences between deliveries in left-handed pitchers. The practical significance of these results, however, may be more difficult to interpret.