Executive functions in learning processes: Do they benefit from physical activity?

As executive functions play an essential role in learning processes, approaches capable of enhancing executive functioning are of particular interest to educational psychology. Recently, the hypothesis has been advanced that executive functioning may benefit from changes in neurobiological processes induced by physical activity. The present research explored this hypothesis by systematically identifying and reviewing intervention studies targeting the relationship between physical activity and executive functions, distinguishing between different types of intervention and of executive function. The review found considerable evidence for beneficial effects of physical activity on executive functions, with performance benefitting more consistently in inhibition tasks than in dual task coordination, shifting tasks, or combined tasks. Possible physiological explanations are discussed. Open questions for application and future research concern the sustainability of effects, the design of physical activity interventions, and the role of individual differences. Possible interventions applicable to educational settings are discussed.     

Acceleratory match-play demands of a Super Rugby team over a competitive season

The match-play demands of rugby union have increased over time, and these demands should be quantified so as to provide a basis for optimal player loading during training. The primary aim of this article was to quantify accelerations, decelerations, impacts and aggregated body demands during the first half of match-play in a Super Rugby team. The secondary aim was to determine whether these characteristics are position-specific. Thirty-three players were monitored for 14 matches using global positioning system units with inbuilt microtechnology. Players were grouped according to positional roles and data were analysed for those who completed the entire duration of the first half of a given match. Forwards sustained more (d = 0.44) high-intensity impacts and greater (d = 0.26) aggregated body demands, while backs had more moderate (d = 0.55) and heavy accelerations (d = 0.76), and moderate (d = 0.23) and heavy decelerations (d = 0.54). These differences suggest that conditioning and recovery strategies should reflect the physical demands placed on players in different playing positions. Forwards should be conditioned with a focus on impacts and require longer recovery for the same duration of playing time, whereas conditioning for backs should emphasise rapid accelerations and decelerations.     

Generierung interaktiver Animationen von Berechnungsmodellen

In diesem Artikel werden zwei generative Ans?tze für animierte Berechnungsmodelle vorgestellt und im Kontext von Lernsoftware für den Compilerbau angewandt. Zuerst wird eine Implementierung für den ersten Ansatz beschrieben. Basierend auf der Erfahrung mit diesem Prototypen wurde der zweite Ansatz entwickelt und das Ganimal Rahmenwerk entworfen. Es handelt sich dabei um ein generisches Algorithmenanimationssystem, das eine für ein solches System einzigartige Fülle an M?glichkeiten durch sein graphisches Basispaket, das nebenl?ufige Laufzeitsystem mit graphischer Benutzeroberfl?che und die Programmier- und Animationsbeschreibungssprache Ganila bietet.     

Weblogs for organizational knowledge sharing and creation: a comparative case study

The use of weblogs as an information and communication technology for knowledge sharing and creation is a novel social and organizational phenomenon. In this paper, we identify and explain contingency factors that influence the successful use of weblogs for knowledge sharing and creation. We start from the assumption that successful knowledge management requires the motivation of people to engage in knowledge-related communication. Based on a comparison of two antithetic cases, we identify and discuss four contingency factors that directly influence the motivational impact of weblogs on organizational knowledge sharing and creation.     

Taking away and determining the difference—a longitudinal perspective on two models of subtraction and the inverse relation to addition

Subtraction can be understood by two basic models—taking away (ta) and determining the difference (dd)—and by its inverse relation to addition. Epistemological analyses and empirical examples show that the two models are not relevant only in single-digit arithmetic. As curricula should be developed in a longitudinal perspective on mathematics learning processes, the article highlights some exemplary steps in which the inverse relation is discussed in light of the two models, namely mental subtraction, the standard algorithms for subtraction, negative numbers and manipulations for solving algebraic equations. For each step, the article presents educational considerations for fostering a flexible use of the two models as well as of the inverse relation between subtraction and addition. In each section, a mathe-didactical analysis is conducted, empirical results from literature as well as from our own case studies are presented and consequences for teaching are sketched.     

The acceptability of lies: A comparison of Ecuadorians and Euro-Americans

This study examined differences between Ecuadorian and Euro-American college students in the perceived acceptability of lies. Six different lie domains were examined: flattery, impression management, conflict avoidance, enhancement of others’ self-esteem, self-aggrandizement, and instrumental lies. Overall, Euro-Americans rated lies as more acceptable than Ecuadorians. In both cultures, lies motivated by a desire to benefit others were considered to be more acceptable than lies that primarily benefited the self. Additionally, lying to the outgroup was perceived as being more acceptable than lying to the ingroup. These results were interpreted in light of the findings that Ecuadorians scored higher on measures of uncertainty avoidance and power distance, whereas Euro-Americans scored higher on levels of independence. The implications of these findings for intercultural relations and future directions for research are discussed.     

Muscle morphology of the vastus lateralis is strongly related to ergometer performance,sprint capacity and endurance capacity in Olympic rowers

Rowers need to combine high sprint and endurance capacities. Muscle morphology largely explains muscle power generating capacity, however, little is known on how muscle morphology relates to rowing performance measures. The aim was to determine how muscle morphology of the vastus lateralis relates to rowing ergometer performance, sprint and endurance capacity of Olympic rowers. Eighteen rowers (12♂, 6♀, who competed at 2016 Olympics) performed an incremental rowing test to obtain maximal oxygen consumption, reflecting endurance capacity. Sprint capacity was assessed by Wingate cycling peak power. M. vastus lateralis morphology (volume, physiological cross-sectional area, fascicle length and pennation angle) was derived from 3-dimensional ultrasound imaging. Thirteen rowers (7♂, 6♀) completed a 2000-m rowing ergometer time trial. Muscle volume largely explained variance in 2000-m rowing performance (R² = 0.85), maximal oxygen consumption (R² = 0.65), and Wingate peak power (R² = 0.82). When normalized for differences in body size, maximal oxygen consumption and Wingate peak power were negatively related in males (r = ?0.94). Fascicle length, not physiological cross-sectional area, attributed to normalized peak power. In conclusion, vastus lateralis volume largely explains variance in rowing ergometer performance, sprint and endurance capacity. For a high normalized sprint capacity, athletes may benefit from long fascicles rather than a large physiological cross-sectional area.     

Machine learning for people detection in guidance functionality of enabling health applications by means of cascaded SVM classifiers

Electronic assistance devices for visually impaired people often require pedestrian detection functionality. Due to the fact that these devices have only low computational processing capabilities, it is necessary to use realtime algorithms that meet these requirements.We thus propose application of a cascaded support vector machine (SVM) classifier with linear and combined cascading of SVMs based on histogram of oriented gradients (HOGs) and Fisher score preselection. Proposed algorithms are evaluated on the basis of the INRIA database and compared to the state of the art procedure with HOG-features in combination with a standard SVM.