Creatine kinase,myosin heavy chains and magnetic resonance imaging after eccentric exercise

The aim of this study was to examine the relationship between myosin heavy chain (MHC) release as a specific marker of slow-twitch muscle fibre breakdown and magnetic resonance imaging (MRI) of skeletal muscle injury after eccentric exercise. The effects of a single series of 70 high-intensity eccentric contractions of the quadriceps femoris muscle group (single leg) on plasma concentrations of creatine kinase and MHC fragments were assessed in 10 young male sport education trainees before and 1 and 4 days after exercise. To visualize muscle injury, MRI of the loaded thigh was performed before and 4 days after the eccentric exercise. All participants recorded an increase ( P ? 0.05) in creatine kinase after exercise. In five participants, T2 signal intensity was unchanged post-exercise compared with pre-exercise and MHC plasma concentration was normal; however, they showed an increase ( P ? 0.05) in creatine kinase after exercise. For the remaining five participants, there was an increase in T2 signal intensity of the loaded vastus intermedius and vastus lateralis. These changes in MRI were accompanied by an increase in MHC plasma concentration ( P ? 0.01) as well as an increase in creatine kinase ( P ? 0.01). We suggest that changes in MRI T2 signal intensity after muscle damage induced by eccentric exercise are closely related to damage to structurally bound contractile filaments of some muscle fibres. Additionally, MHC plasma release indicates that this damage affects not only fast-twitch fibres but also some slow-twitch fibres.     

What do we learn from docutainment? Processing hybrid television documentaries

This study examined how hybrid documentary formats, which embed educational contents into narratives, are cognitively processed. Based on existing research and theories, two reception modes were identified: processing with a focus on the narrative plotline and processing with a focus on the thematic structure. In two experiments, two markers of narrative processing could be found for hybrid television documentaries: the experience of transportation and the narrative distance effect. In the first experiment, it could be shown that re-enactments and personal variables enhance the experience of transportation. The second experiment confirmed the narrative distance effect, which occurs independently of reception goals. This means that educational facts which are closely tied to the narrative plotline were learned better than distant facts, regardless of whether the recipients watched the documentary for information or entertainment purposes. The study supplements prior theories on hybrid processing and provides conditions under which narratives are appropriate for learning.     

Training the use of interactive videos: effects on mastering different tasks

This study was concerned with identifying prerequisites for the successful use of videos that offer different levels of interactivity. In a homework scenario, 64 ninth graders participated either in a search training demonstrating the efficient use of features facilitating the selection of relevant information or in a control training focusing on the integration of new information with prior knowledge. Following the training, the participants used either a common video that allowed them to control the transient flow of the information via stop and browsing or an enhanced video that additionally facilitated the localization of information via chapter selection and an index. Overall, the students wrote two essays (Essay 1: summary; Essay 2: argument) and performed a search task. The study revealed that, independent of the training condition, students benefitted from the enhanced video for the search task which merely required naming isolated facts. Moreover, in a summary task, the enhanced video resulted in the consideration of information from more different chapters when the task required gathering information from the video; however, this broader consideration of chapters only translated into naming more information after the search training. The data of a second essay requiring inferences about the video’s contents (argument) were not analyzed due to a floor effect. Taken together, these results indicate that the characteristics of a task as well as the students’ knowledge of respective search strategies need to be considered when implementing interactive features in video environments.     

French communications

LAMY DROIT DE L'INFORMATIQUE. INFORMATIQUE, MULTIMEDIA RÉSEAUX, INTERNET / COMPUTER LAW: COMPUTERS, MULTIMEDIA RESEARCH, INTERNET (Paris: Lamy SA, 1997 [11th ed.]—FF1790, ISBN 2–7212–0699–0, 1,645 pp.)

INTERNET by Arnaud Dufour (Paris: Presses Universitaires de France [PUF] “Que Sais‐Je, No. 3073,”; June 1996 [3rd ed.]— FF20, ISBN 2–13–047469–1, 128 pp.)

LE RÉGIME JURIDIQUE COMMUNAUTAIRE DES SERVICES DE TÉLÉCOMMUNICATIONS/EUROPEAN TELECOMMUNICATION SERVICES REGIME Annie Blandin‐Obernesser (Paris: Armand Colin Editeurs “Collection Technique et Scientifique des Telecommunications,”; August 1996—price not available, ISBN 2–200–01409–0, 211 pp.)

LA DÉRÉGLEMENTATION DES TÉLÉCOMMUNICATIONS DANS LES GRANDS PAYS INDUSTRIELS/TELECOMMUNICATIONS DEREGULATION IN INDUSTRIALIZED COUNTRIES by Laurence Bancel‐Charensol (Paris: Economica “Management, Communication, Reseaux,”; 1996— FF198, ISBN 2–7178–3068–5, 350 pp., charts, tables, references, bibliography)