Pedometer reliability, validity and daily activity targets among 10- to 15-year-old boys

The aims of this study were to: (1) determine whether the number of pedometer counts recorded by adolescents differs according to the adiposity of the participant or location on the body; (2) assess the accuracy and reliability of pedometers during field activity; and (3) set adolescent pedometer-based physical activity targets. Seventy-eight 11- to 15-year-old Boy Scouts completed three types of activity: walking, fast walking and running. Each type was performed twice. Participants wore three pedometers and one activity monitor during all activities. Participants were divided into groups of normal weight (BMI < 85th percentile) and at risk of being overweight (BMI > or = 85th percentile). Intra-class correlations across the three activities indicated reliability (r = 0.51 - 0.92, P < 0.001). This conclusion was supported by narrow limits of agreement that were within a pre-set range that was practically meaningful. Multivariate analysis of covariance indicated adiposity group differences, but this difference was a function of the increased stature among the larger participants (P < 0.001). Ordinary least-squares regression models and multi-level regression models showed positive associations between the number of pedometer and activity monitor counts recorded by the three groups of participants during all activities (all P < 0.001). The mean number of counts recorded for all participants during the fast walk was 127 counts per minute. In conclusion, the pedometers provided an accurate assessment of adolescent physical activity, and a conservative estimate of 8000 pedometer counts in 60 min is equivalent to 60 min of moderate to vigorous physical activity.     

Analysis and conservation of modern modeling materials found in Auguste Rodin's sculptures

Prior to the exhibition Portrait-making, Rodin and his models (2009), the Rodin museum wanted to restore two busts of Hanako and Clemenceau. Interestingly, these two sculptures contain pieces of modern modeling materials (MMMs) invented at the end of the nineteenth century as an alternative to clay or waxes. The poor state of conservation of the two portraits made any handling and exhibition impossible. Accordingly, the purpose of this article is twofold: to contribute to technical art history and conservation. Elemental and chemical analyses were done on samples from 12 sculptures (SEM–EDX, FTIR, GC–MS, GC–FID, XRD, synchrotron-based µXRF, µXANES, and µFTIR) aimed at identifying the composition of MMMs used by Rodin on plaster sculptures and establishing hypotheses about the origins of their degradation. This thorough study of their composition and degradation was necessary to implement an appropriate restoration plan. The development of conservation protocols adapted to such materials is rarely documented. Different tests were performed on mock-ups (pH, solubility, adhesion, consolidation, and cleaning). In particular, a protocol based on laser cleaning was developed and successfully applied to remove superficial dust and crusts so that the sculptures regained their original aspect.     

Self-replicating digital data storage with synthetic chromosomes

With the rapid development of the Internet and computational technolo-gies,the exponential growth of digital data is beginning to overwhelm existing storage dev...     

Dubious Early Medieval Jewels from Matzhausen (Bavaria): New Material and Technological Investigations

ABSTRACT

A controversial set of elite jewels assumed to be of early medieval period, recovered in 1937–1938 from a burial site in Matzhausen (northeastern Bavaria) was investigated to determine their technological coherency as well as their authenticity. The discovery of these jewels was exploited by German nationalists to argue that the material culture observed in Bohemia and Moravia in the ninth century had Germanic roots. The circumstances of their discovery, however, remain unclear. Research in archives demonstrated the involvement of the SS Ahnenerbe organisation in the recovery of the jewels. Are these jewels authentic or are they forgeries manufactured or modified by a modern craftsman to serve German expansionist nationalism? Three jewels recovered in the grave – a gombik (hollow spherical pendant), an earring with chainlet, and a zoomorphic figurine – were investigated using scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX), X-radiography, and stereomicroscopy. The investigation revealed a very heterogeneous set of objects with respect to technology and state of preservation. It also uncovered repairs and past invasive interventions involving modern metal and solder. Comparison with similar types of jewels from Bohemia and Moravia points to important differences in construction and technology, which confirms the uniqueness of this set of objects and casts suspicion on their authenticity.     

Cooperative learning: a relevant instructional model for physical education pre-service teacher training?

Background: One of the key questions of physical education teacher educators (PETE) programmes refers to whether future teachers are prepared to build knowledge and skills to feel self-efficacious in teaching physical education (PE). This issue concerns the instructional model of teaching used to help PE pre-service teachers to master both pedagogical knowledge and motor skills. According to this twofold challenge, the direct instruction (DI) is mainly used for pre-service teacher training. Beyond this traditional model, other instructional models as cooperative learning (CL) approach arise in the initial PE teacher education. Nevertheless, surrounding attempts at innovation, little information related to the instructor’s role. Under the social cognitive perspective of self-efficacy and instructional competency building, more information is currently expected with regard to the strategies the instructor uses to scaffold the mastery of skills for PE pre-service teachers’ effective teaching.

Purpose: The purpose of this article is to consider whether PE pre-service teachers are trained during short training sessions aimed to discover new physical activities. We examine the influence of a scaffolding procedure (CLS design) on PE pre-service teachers’ knowledge, skills and self-efficacy in comparison to a CL and a DI experience. This leads to consider to what extent this instructional support provided by the instructor would help pre-service teachers to perceive themselves as self-efficacious to teach contents in PE.

Participants and design: After a pre-test, sixty-nine PE pre-service teachers were randomly assigned to one of the three following conditions: CL (14 males and 7 females); CLS (20 males and 8 females) or direct instruction condition (DI; 12 males and 8 females). For the training session a selected CL procedure (Jigsaw) [Aronson, Elliot, and Shelley Patnoe. 1997. The Jigsaw Classroom: Building Cooperation in the Classroom. 2nd ed. Wokingham: Addison-Wesley Educational]) was used to split CL and CLS participants into mixed-sex teams, whereas DI participants practiced the same exercises in dyads. According to the training conditions, the same instructor provided different information to participants along the three 2-hour instructional sessions with regard to: (a) warm-up (DI), (b) CL organization (CL), and (c) scaffolding integrated into a CL implementation (CLS).

Data collection: A Pre-test/post-test design was used to consider PE pre-service teacher’s motor skill, knowledge for practice, and self-efficacy improvements. The post-test also examined participants’ pedagogical knowledge.

Findings: The results showed that the participants in the three conditions progressed on performance, knowledge for practice, knowledge for teaching, and self-efficacy. Although no difference was found in self-efficacy between the three training conditions over time, significant differences appeared on pedagogical knowledge or/and motor skills with an advantage for the CL and CLS participants, respectively.

Conclusion: Although short training sessions dedicated to discovering new sports stay problematic for teacher professional development, implementing CL pre-service teacher training designs would be a relevant alternative. Instructional knowledge would be developed mainly when they have explicitly access to information concerning the teacher intervention. Nevertheless, such a scaffolding procedure integrated into CL training designs would need to be applied repeatedly to various physical activities to have an impact on pre-service teachers’ self-efficacy.