Three dimensional musculoskeletal modelling of the seated biceps curl resistance training exercise

The aim of this study was to evaluate the benefits and limitations of using three dimensional (3D) musculoskeletal modelling (LifeModeler) in assessing the safety and efficacy of exercising on a seated biceps curl resistance training machine. Three anthropometric cases were studied, representing a 5th percentile female, 50th percentile and 95th percentile male. Results indicated that the LifeModeler default model was not adequate to solve the forward dynamics simulations. Therefore adjustments had to be made to the default model to successfully complete the forward dynamics simulations. The software was able to sufficiently highlight the shortcomings of the biceps curl machine's engineered adjustability in relation to the anthropometric dimensions of the studied cases, as the 5th percentile female could not be accommodated suitably on the machine. High lumbar spine anterior/posterior shear forces for all anthropometric cases and maximum muscle tensions for the female and 50th percentile male indicate that the seated biceps curl exercise may pose risks for injuries. To conclude, it appears that 3D musculoskeletal modelling can be used to evaluate resistance training equipment such as the seated biceps curl machine. However the limitations as indicated by this study must be taken into consideration, especially when using the default LifeModeler model.     

Personal development of disadvantaged youth through community sports: a theory-driven analysis of relational strategies

Abstract

Participant–practitioner relationships in community ‘sport-for-development’ practices are seen as central in working towards broader developmental outcomes. Using Noddings’ Ethics of Care as an analytical framework, we investigated relational strategies of practitioners in three community sport practices (Belgium) to understand the personal developmental potential of these relationships. Based on the data (participatory observations, interviews, focus groups), we identified the following themes that are viewed as fundamental in building relationships that hold the potential to instigate personal development for young people in disadvantaged situations: (a) time demanding interactions, (b) authenticity of practitioners, (c) equalizing expertise, (d) non-judgmental approach, (e) practitioners’ cultural capital, (f) co-organizing activities, (g) a ‘thousand chances’ philosophy, and (h) providing individual support. The identified themes can be used to develop youth-centred and qualitative evaluation methodologies that are more congruent with the daily work of community sport workers and, by doing so, go beyond a narrow quantitative ‘outcome-fixated’ evaluation dogma.     

Mastery of the counting principles in toddlers: A crucial step in the development of budding arithmetic abilities?

Counting abilities have been described as determinative precursors for a good development of later arithmetic abilities. Mastery of the stable order, the one–one-correspondence and the cardinality principles can be seen as essential features for the development of counting abilities. Mastery of the counting principles in kindergarten was assessed in a large group of children with a broad range of arithmetic abilities (N = 423). Not all children mastered the counting principles by the end of kindergarten. Mastery of the counting principles in kindergarten was predictive for arithmetic abilities one year later in first grade, especially for scores on arithmetic achievement tests. Children sharing a common educational background tend to have more similar scores on arithmetic tests, yet the importance of mastery of the essential counting principles in the prediction of later arithmetic achievement was the same for all classrooms.     

Observational learning from animated models: Effects of modality and reflection on transfer

Animated models use animations and explanations to teach how a problem is solved and why particular problem-solving methods are chosen. Often spoken explanations are proposed to accompany animations in order to prevent overloading the visual channel (i.e., the modality effect). In this study we adopt the hypothesis that the inferior performance of written text compared to spoken text is due to the fact that written text receives less attention and, consequently, less effortful processing. In a 2 × 2 factorial experiment (N = 96) with the factors modality (written, spoken) and reflection (reflection prompts, no reflection prompts) the hypothesis is tested that prompted reflection requires learners to explicitly attend to written explanations and carefully process them, thus yielding higher transfer performance, whereas for spoken explanations prompted reflection would have no effect on transfer performance. The results indeed showed the hypothesized interaction between modality and reflection prompts. They suggest that the modality effect can be compensated for when learners explicitly attend to the information and effortfully process it. This has implications for learning situations in which spoken explanations are no option, such as education for the hearing-impaired.     

Les Effets de Coopération et de Feedback par les Compagnons de Classe sur la Performance Orthographique

European Journal of Psychology of Education -     

Quantum lithography: A?non-computing application of quantum information

Quantum information theory holds the promise of revolutionizing technologies other than computing and communications. In this article we show how quantum entanglement can be harnessed to beat the Rayleigh diffraction limit of conventional optical lithography, and to permit nano-devices to be fabricated at a scale arbitrarily shorter than the wavelength used. Given the relative ease of performing optical lithography compared with other schemes, and the relative costs associated in migrating the lithography industry to each new fabrication technology, exploiting quantum entanglement to extend the useful life of optical lithography could be economically attractive.     

Associations between academic and motor performance in a heterogeneous sample of children with learning disabilities

A heterogeneous sample of 137 school-aged children with learning disabilities (IQ > 80) attending special needs schools was examined on the Movement Assessment Battery for Children (MABC). The results show that compared to the available norm scores, 52.6% of the children tested performed below the 15th percentile on manual dexterity, 40.9% on ball skills, and 33.7% on balance skills. Furthermore, after controlling for IQ, significant small to moderate partial correlations were found between spelling and mathematics and the MABC total score, as well as small to moderate correlations between mathematics and balance, between reading and ball skills, and between spelling and manual dexterity. The present findings are compared with previously reported results obtained in more homogenous groups, and based on the resultant relationships between academic performance and motor development, recommendations for future motor intervention studies are made.     

Running speed-induced changes in foot contact pattern influence impact loading rate

Purpose. We aimed to determine the effect of speed-induced changes in foot contact patterns on the vertical instantaneous loading rate (VILR). We hypothesized that transition runners, i.e. runners that shift towards a mid- (MF) or forefoot contact pattern (FF) when running speed increases, show smaller increases in VILR than non-transition runners, i.e. runners that remain with a rearfoot contact pattern (RF).

Methods. Fifty-two male and female runners ran overground at 3.2, 4.1, 5.1 and 6.2?m?s^?1. Ground reaction forces, lower limb sagittal plane knee and ankle kinematics and plantar pressures were recorded. Multi-level linear regression models were used to assess differences between transition and non-transition runners.

Results. Non-transition runners experienced larger speed-induced increases in VILR (48.6?±?2.6?BW?s^?1 per m?s^?1) than transition runners (–1.4?±?7.6?BW?s^?1 per m?s^?1). Transition runners showed higher VILRs and a more flat foot touch down at the same pre-transition speed than non-transition runners.

Conclusion. When running speed increases, some runners transition towards more anterior foot contact patterns. This reduces or even eliminates the speed-induced increase in VILR. This result is especially the case for those RF runners who already have relatively high VILRs and flat foot positioning at slower running speeds.     

Detection of macroenzymes: establishing upper reference limits for eight enzymes after polyethylene glycol precipitation

IntroductionThe presence of macroenzymes in blood can cause diagnostic confusion. Therefore, confirming the presence of macroenzymes is important to reduce unnecessary (non-)invasive investigations. Polyethylene glycol (PEG) precipitation is a simple and fast first-line method for the detection of macroenzymes. However, there is no consensus on the upper reference limit for the PEG-precipitable activity (%PPA) of monomeric enzymes. The aim of this study was to verify a PEG precipitation protocol for the detection of macroenzymes in our laboratory by establishing upper reference limits (URLs) and determining imprecision for eight enzymes after PEG precipitation. In addition, we aimed to clinically verify the URLs using samples containing macroenzymes as identified by electrophoresis.Materials and methodsPer enzyme, at least 40 leftover blood samples from adult patients with either normal or increased enzyme activities were diluted 1:1 with 25% PEG 6000 and 1:1 with 0.9% NaCl. Mixtures were incubated for 10 min at 37°C and centrifuged. Supernatant enzyme activity was measured on Cobas c702 and the %PPA was calculated.ResultsThe following URLs were obtained: 26% PPA for amylase, 29% PPA for alkaline phosphatase (ALP), 61% PPA for alanine aminotransferase, 48% PPA for aspartate aminotransferase, 24% PPA for creatine kinase (CK), 55% PPA for gamma-glutamyltransferase, 65% PPA for lactate dehydrogenase, and 56% PPA for lipase. The within-lab imprecision was < 15%. Regarding the clinical verification, the two historical samples with proven macroCK showed a %PPA of 69% and 43%, respectively, and a sample with proven macroALP had a %PPA of 52%.ConclusionIn this study, URLs for monomeric enzyme activities after PEG precipitation for eight different enzymes were established. The URLs are suitable for clinical use, but are only partially in line with other studies. Therefore, our data highlight the importance of establishing laboratory-specific upper reference limits for %PPA to allow a correct interpretation.     

The transient role of explicit phonological recoding for reading acquisition

This study explores early stages of reading acquisition, specifically therelation of phoneme blending and letter recoding to individual differencesin word decoding. The hypothesis was that facility in letter recoding andaccuracy of phoneme blending are substantial components of word decodingin beginning readers but not for skilled reading and that reliance onphoneme-sized decoding of words would dissipate as reading proficiencyincreased. In four studies we examined the ability to recode letters, blendphonemes and decode words in four groups of Dutch children (early Grade1, N = 130, older Grade 1, N = 81, Grade 3, N = 54 and a group of children witha reading lag, N = 356). Phoneme blending was only related to the readingability of beginning Grade 1 children. By the end of Grade 1 ability to blendphonemes did not differentiate reading capacity, nor for older children inGrade 3 and reading disabled children. Letter recoding was related to worddecoding in all four studies, although the strength of that relation diddwindle as reading skill level increased. The results of the study appearconsistent with self teaching hypothesis and other theories that imply atransient role of explicit phonological recoding in word identification.