Fixed versus free-floating stretcher mechanism in rowing ergometers: mechanical aspects

The mechanical responses (i.e. external contact forces and external power) of 25 elite rowers to a race-pace rowing protocol were investigated on the traditional fixed stretcher mechanism and the more recently introduced free-floating stretcher mechanism rowing ergometers. Using a Rowperfect rowing ergometer for both conditions, external contact forces at the handle, stretcher and sliding seat, as well as the displacements of the handle and stretcher, were recorded. The external power was calculated as the product of the force and velocity data from both the handle and stretcher. Significant differences (P < 0.05) between the two conditions for each mechanical parameter were observed. The fixed condition showed larger maximum values for forces and external power and average power throughout the rowing cycle. Moreover, rowing with the fixed mechanism generated higher inertial forces during the transition between the propulsion and recovery phases, especially at the catch of the cycle. The results suggest that: (i) muscular coordination may differ according to the stretcher mechanism used, which could have an impact on the physiological adaptations of muscles; and (ii) the free-floating mechanism may induce lower catch and maximum values for net joint forces and net joint moments that could decrease the risk of injury.     

The evolution of oscillatory behavior during learning on a ski simulator

Recent experiments on the ski simulator produced ambiguous results and raised unanswered questions concerning the true nature of "novice" behavior and the occurrence of behavioral changes during learning. The aim of the present experiment was to analyze the evolving behavior of three beginners during six practice sessions on a ski simulator The position of the apparatus platform was recorded as time series and used for constructing dynamical models, including stiffness and damping functions. The results showed that novices tended to exploit a Rayleigh damping behavior during the first trials and then transition toward a van der Pol damping. These results replicate previous observations by Nourrit, Delignieres, Caillou, Deschamps, and Lauriot (2003) and suggest the transition to the expert behavior could arise early in practice, when the task is of moderate difficulty. The discussion focuses on the properties of the observed learning dynamics and proposes a global conceptualization for acquiring complex motor skills.     

Les six étapes de l'apprentissage des structures

Sans résuméPublié, avec illustrations, sous forme d'un petit livre, par O.C.D.L., Paris.     

Enhancing the MeSH thesaurus to retrieve French online health resources in a quality-controlled gateway

The amount of health information available on the Internet is considerable. In this context, several health gateways have been developed. Among them, CISMeF (Catalogue and Index of Health Resources in French) was designed to catalogue and index health resources in French. The goal of this article is to describe the various enhancements to the MeSH thesaurus developed by the CISMeF team to adapt this terminology to the broader field of health Internet resources instead of scientific articles for the medline bibliographic database. CISMeF uses two standard tools for organizing information: the MeSH thesaurus and several metadata element sets, in particular the Dublin Core metadata format. The heterogeneity of Internet health resources led the CISMeF team to enhance the MeSH thesaurus with the introduction of two new concepts, respectively, resource types and metaterms. CISMeF resource types are a generalization of the publication types of medline. A resource type describes the nature of the resource and MeSH keyword/qualifier pairs describe the subject of the resource. A metaterm is generally a medical specialty or a biological science, which has semantic links with one or more MeSH keywords, qualifiers and resource types. The CISMeF terminology is exploited for several tasks: resource indexing performed manually, resource categorization performed automatically, visualization and navigation through the concept hierarchies and information retrieval using the Doc'CISMeF search engine. The CISMeF health gateway uses several MeSH thesaurus enhancements to optimize information retrieval, hierarchy navigation and automatic indexing.     

Mapping the biomedical sciences using Medical Subject Headings: a comparison between MeSH co-assignments and MeSH citation pairs

Objective:This study compares two maps of biomedical sciences using Medical Subject Headings (MeSH) term co-assignments versus MeSH terms of citing/cited articles and reveals similarities and differences between the two approaches.Methods:MeSH terms assigned to 397,475 journal articles published in 2015, as well as their 4,632,992 cited references, were retrieved from Web of Science and MEDLINE databases, respectively, which formed over 7 million MeSH co-assignments and nearly 18 million direct citation pairs. We generated six network visualizations of biomedical science at three levels using Gephi software based on these MeSH co-assignments and citation pairs.Results:The MeSH co-assignment map contained more nodes and edges, as MeSH co-assignments cover all medical topics discussed in articles. By contrast, the MeSH citation map contained fewer but larger nodes and wider edges, as citation links indicate connections to two similar medical topics.Conclusion:These two types of maps emphasize different aspects of biomedical sciences, with MeSH co-assignment maps focusing on the relationship between topics in different categories and MeSH direct citation maps providing insights into relationships between topics in the same or similar category.     

Experimenting ‘learn by doing’ and ‘learn by failing’

According to the literature, in recent years, developing experiential learning has fulfilled the requirement of a deep understanding of lean philosophy by engineering students, demonstrating the advantages and disadvantages of some of the key principles of lean manufacturing. On the other hand, the literature evidences how some kinds of game-based experiential learning overlook daily difficulties, which play a central role in manufacturing systems. To fill the need of a game overcoming such lack of vision, an innovative game direct in-field, named Kart Factory, has been developed. Actual production shifts are simulated, while keeping all the elements peculiar to a real production set (i.e. complexity, effort, safety). The working environment is a real pedal car assembly department, the products to be assembled have relevant size and weight (i.e. up to 35 kg approximately), and the provided tools are real production equipment (e.g. keys, screwdrivers, trans-pallets, etc.). Due to the need to maximise the impact on students, a labour-intensive process characterises the production department. The whole training process is based on three educational principles: Experience Value Principle, Error Value Principle, and Team Value Principle. As the ‘learn by doing’ and ‘learn by failing’ are favoured, the theory follows the practice, while crating the willingness to ‘do’ instead of just designing or planning. The gathered data prove the Kart Factory's effectiveness in reaching a good knowledge of lean concepts, notwithstanding the students’ initial knowledge level.     

Increasing Knowledge Flows between the Agricultural Research and Advisory System in Italy: Combining Virtual and Non-virtual Interaction in Communities of Practice

Purpose: The aim of the paper is to analyse the use of Communities of Practice and Information and Communication Technology (ICT) to enhance knowledge sharing between researchers and advisors. The associated research question is to what extent ICT supported a virtual Community of Practice and has been effective in counteracting fragmentation between research and advisory systems in terms of knowledge sharing between these two pillars of the Italian Agricultural Knowledge System (AKS).

Design/Methodology/approach: The paper uses a mixed methods approach: a questionnaire submitted to the Community of Practice participants on their experiences, observation of interaction between Community of Practice participants and data on the use of the ICT platform.

Findings: The ICT supported Community of Practice approach appears to improve knowledge sharing between researchers and advisors, and also draws in other actors of the broader Agricultural Knowledge and Innovation System in which the AKS is embedded. However, ICT based tools alone are not sufficient and need to be complemented with face-to-face (non-virtual) interactions. A clear theoretical implication of this study is that this is an iterative process in which virtual and non-virtual interaction mutually reinforce each other: ICT interaction spurs real life and face-to-face interaction, and ICT supports follow-up on real life face-to-face interaction.

Practical Implications: Communities of Practice can be a useful tool for knowledge sharing between research and advisory systems, but should have a degree of flexibility in terms of the topics they address and should accommodate new members when appropriate. ICT is supportive, but should be complemented by real life meetings.

Originality/Value: The paper connects recent frameworks of the use of Communities of Practice with literature on ICT in agriculture and adds insights on the contribution of combining virtual and non-virtual interaction in Communities of Practice aimed at knowledge sharing.     

Neural Correlates of Self and Its Interaction With Memory in Healthy Adolescents

Adolescence is marked by the development of personal identity and is associated with structural and functional changes in brain regions associated with Self processing. Yet, little is known about the neural correlates of self‐reference processing and self‐reference effect in adolescents. This functional magnetic resonance imaging study consists of a self‐reference paradigm followed by a recognition test proposed to 30 healthy adolescents aged 13–18 years old. Results showed that the rostral anterior cingulate cortex is specifically involved in self‐reference processing and that this specialization develops gradually from 13 to 18 years old. The self‐reference effect is associated with increased brain activation changes during encoding, suggesting that the beneficial effect of Self on memory may occur at encoding of self‐referential information, rather than at retrieval.     

Time-motion,tactical and technical analysis in top-level karatekas according to gender,match outcome and weight categories

The aim of this study was to define the time-motion (i.e., fighting, preparatory and breaking activity), technical (i.e., attack, timed-attack, counterattack, blocking and grasps) and tactical (i.e., upper limb, lower-limb, combination and throwing) profiles of the senior top-level karate competition played under the most recent rules of the International Karate Federation in relation to gender, match outcome and weight categories. Time-motion, tactical actions and technical executions were investigated of senior karatekas (n = 60) during the Karate World Championship. The referee’s decisions caused an overall activity-to-break ratio of ~1:1.5 with a significant difference (P = 0.025) between karateka’s weight categories (light = 1:1.5; middle = 1:2 and heavy = 1:1). High-intensity actions (i.e., attack and defensive actions performed quickly and powerfully) were higher in male compared to female athletes. Top-level karatekas used upper limb techniques more than lower limb ones, with both applied in the head more than in the body. For the high-intensity-actions to pause ratio and the percentage of combined techniques, light weight category was significantly higher than middle weight category. These findings suggest that training programs may need to be specific to the requirements of the gender and weight categories.     

Elitebildungsforschung im Vergleich – Frankreich,USA und Großbritannien

Research on elites (that is, on status groups that occupy dominant positions) is characterized by the lack of connection between studies that focus on elite recruitment and those that focus on the exercise of power by elites. As underlined by Giddens (Elites and power in British society, 1974), both types of approach are important and should complement each other in the analysis of mediations between the class structure, the organizational structure and the power structure in a given society. Giddens also insists on the need for recruitment studies to take account of two different dimensions: the types of channel that are privileged by elite groups to reproduce their social position, and the degree of social closure or openness of these channels to other groups (Parkin, The social analysis of class structure, 1974). This distinction is used to organize the present chapter, which focuses on a single channel that has come to play a crucial role in post-industrial societies, that is schools and, more precisely, upper secondary and higher education institutions, and on their influence in three different national contexts: France, the United Kingdom and the United States. In the first section, the specific features of elite education are examined. The second section explores the extent and modes of institutional and social closure.