Physiological and biomechanical responses to walking underwater on a non-motorised treadmill: effects of different exercise intensities and depths in middle-aged healthy women     

Piero Benelli  Franca Colasanti  Massimiliano Ditroilo  Antonio Cuesta-Vargas  Giorgio Gatta  Francesco Giacomini 《Journal of sports sciences》2013,31(3):268-277

Abstract

Non-motorised underwater treadmills are commonly used in fitness activities. However, no studies have examined physiological and biomechanical responses of walking on non-motorised treadmills at different intensities and depths. Fifteen middle-aged healthy women underwent two underwater walking tests at two different depths, immersed either up to the xiphoid process (deep water) or the iliac crest (shallow water), at 100, 110, 120, 130 step-per-minute (spm). Oxygen consumption (VO₂), heart rate (HR), blood lactate concentration, perceived exertion and step length were determined. Compared to deep water, walking in shallow water exhibited, at all intensities, significantly higher VO₂ (+13.5%, on average) and HR (+8.1%, on average) responses. Water depth did not influence lactate concentration, whereas perceived exertion was higher in shallow compared to deep water, solely at 120 (+40%) and 130 (+39.4%) spm. Average step length was reduced as the intensity increased (from 100 to 130 spm), irrespective of water depth. Expressed as a percentage of maximum, average VO₂ and HR were: 64–76% of peak VO₂ and 71–90% of maximum HR, respectively at both water depths. Accordingly, this form of exercise can be included in the “vigorous” range of exercise intensity, at any of the step frequencies used in this study.  相似文献   

Stabilization and passification of distributed-order fractional linear systems using methods of preservation     

Guillermo Fernández-Anaya  José-Job Flores-Godoy  Armando-Fabian Lugo-Peñaloza  Rodrígo Muñoz-Vega 《Journal of The Franklin Institute》2013,350(10):2881-2900

This paper studies the stabilization and passification of a class of distributed-order linear time-invariant systems, by using methods of preservation in the frequency domain. Results about preservation of stability and passivity of classical linear time-invariant systems are extended to one more general family of matrix functions. Based on these results, a new approach to the problems of stabilization and passification of distributed-order linear time-invariant systems is presented. Also a result that extends the known techniques for pole placement of classical linear time-invariant systems to the new class of distributed-order linear time-invariant systems is given. Examples are given to show the validity of theoretical results.  相似文献   

Providing metrics and automatic enhancement for hierarchical taxonomies     

Ghassan Beydoun  Francisco García-Sánchez  Cristin M. Vincent-Torres  Antonio A. Lopez-Lorca  Rodrigo Martínez-Béjar 《Information processing & management》2013

Taxonomies enable organising information in a human–machine understandable form, but constructing them for reuse and maintainability remains difficult. The paper presents a formal underpinning to provide quality metrics for a taxonomy under development. It proposes a methodology for semi-automatic building of maintainable taxonomies and outlines key features of the knowledge engineering context where the metrics and methodology are most suitable. The strength of the approach presented is that it is applied during the actual construction of the taxonomy. Users provide terms to describe different domain elements, as well as their attributes, and methodology uses metrics to assess the quality of this input. Changes according to given quality constraints are then proposed during the actual development of the taxonomy.  相似文献   

‘Governmentality’ in the origins of European female PE and sport: the Spanish case study (1883–1936)     

Raúl Sánchez García  Antonio Rivero Herraiz 《Sport, Education and Society》2013,18(4):494-510

The purpose of the paper is twofold: (1) to contribute to the analysis of the origins of modern European female PE and sports from a power perspective, inspired by Foucault's work; and (2) to present a detailed analysis of female PE and sport in Spain (1883–1936) as a specific European case study. It is argued that these physical activities could be conceived in the Spanish case as part of a specific kind of ‘governmentality’ with a dual nature. On the one hand they represented disciplinary ‘technologies of power’ over the female body. Selected physical activities—dictated mainly from the hygienic-moral position of the Regeneracionistas (‘Regenerationists’)—were exerted as a kind of ‘bio-power’ for the control of the female population. On the other hand, such kind of activities (especially sports) represented certain ‘technologies of the self’ for middle and upper class women. Through participation in sports, women gained a more active and public role in the Spanish society of the era, obtaining some degree of autonomy in self-governance over their bodies and their lives.  相似文献   

Effects of mat characteristics on plantar pressure patterns and perceived mat properties during landing in gymnastics     

Pedro Pérez-Soriano  Salvador Llana-Belloch  Gaspar Morey-Klapsing  Jose Antonio Perez-Turpin  Juan Manuel Cortell-Tormo 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):245-257

Shock absorption and stability during landings is provided by both, gymnast ability and mat properties. The aims of this study were to determine the influence of different mat constructions on their energy absorption and stability capabilities, and to analyse how these properties affect gymnast's plantar pressures as well as subjective mat perception during landing. Six mats were tested using a standard mechanical drop test. In addition, plantar pressures and subjective perception during landing were obtained from 15 expert gymnasts. The different mats influenced plantar pressures and gymnasts' subjective perception during landing of gymnasts. Significant correlations between plantar pressures at the medial metatarsal and lateral metatarsal zones of the gymnasts' feet with the different shock absorption characteristics of the mats were found. However, subjective perception tests were not able to discriminate mat functionality between the six mats as no significant correlations between the mechanical mat properties with the subjective perception of these properties were found. This study demonstrated that plantar pressures are a useful tool for discriminating different landing mats. Using similar approaches, ideally including kinematics as well, could help us in our understanding about the influences of different mats upon gymnast-mat interaction.  相似文献   

Teaching Modern Chemistry through ‘Recurrent Historical Teaching Models’     

José Antonio Chamizo 《Science & Education》2007,16(2):197-216

Today there are little more of 3 million chemist all over the world producing about 800,000 papers a year. They produce new substances – from some hundreds in 1800 to about 20 million now – the vast majority artificial. This rate is growing quite fast. Once the majority of chemistry teachers all over the world used textbooks as the main (sometimes the only) source of information, we became, without wanting to... history teachers! If ‘scientific literacy’ is the aim of science lessons in school, it is much more than the literacy now developed in science classrooms. It must include an understanding of the nature and process by which scientific activities are carried out. Recognition of the exponentially chemistry knowledge growth and the incompleteness of the current chemistry textbooks are thus intimately related to recognition of the need for recurrent historical teaching models.  相似文献   

Learning design and learning analytics in mobile and ubiquitous learning: A systematic review     

Gerti Pishtari  María J. Rodríguez-Triana  Edna M. Sarmiento-Márquez  Mar Pérez-Sanagustín  Adolfo Ruiz-Calleja  Patricia Santos  Luis P. Prieto  Sergio Serrano-Iglesias  Terje Väljataga 《British journal of educational technology : journal of the Council for Educational Technology》2020,51(4):1078-1100

Mobile and Ubiquitous Learning (m/u-learning) are finding an increasing adoption in education. They are often distinguished by hybrid learning environments that encompass elements of formal and informal learning, in activities that happen in distributed settings (indoors and outdoors), across physical and virtual spaces. Despite their purported benefits, these environments imply additional complexity in the design, monitoring and evaluation of learning activities. The research literature on learning design (LD) and learning analytics (LA) has started to deal with these issues. This paper presents a systematic literature review of LD and LA, in m/u-learning. Apart from providing an overview of the current research in the field, this review elicits elements of common ground between both communities, as shown by the similar learning contexts and complementary research contributions, and based on the research gaps, proposes to: address m/u-learning beyond higher education settings, reinforce the connection between physical and virtual learning spaces, and more systematically align LD and LA processes.  相似文献   

Primary pre-service teachers’ skills in planning a guided scientific inquiry     

Antonio García-Carmona  Ana M. Criado  Marta Cruz-Guzmán 《Research in Science Education》2017,47(5):989-1010

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Perceptual learning transfer in an appetitive Pavlovian task     

Antonio A. Artigas  Jose Prados 《Learning & behavior》2017,45(2):115-123

In two experiments, rats were given intermixed or blocked preexposure to two similar compound stimuli, AX and BX. Following preexposure, conditioning trials took place in which AX (Experiment 1) or a novel compound stimulus NX (Experiment 2) was paired with a food-unconditioned stimulus in an appetitive Pavlovian preparation. Animals that were given alternated preexposure showed lower generalization from AX to BX (Experiment 1) and from NX to a new compound, ZX (Experiment 2), than animals that were given blocked preexposure, a perceptual learning and a perceptual learning transfer effect, respectively.  相似文献   

PGDnet: a new problem‐solving virtual learning environment     

Emilio Gómez  Cristina Rodríguez‐Marciel 《British journal of educational technology : journal of the Council for Educational Technology》2012,43(4):576-591

The purpose of this paper was to provide information about the virtual learning environment known as PGDnet (the Spanish acronym for Plataforma de Gestión Docente or Educational Management Platform in English), which was developed by the innovative education group at the Technical University of Madrid known as “Nuevas metodologías docentes en ingeniería mecánica y fabricación” (New Teaching Methodologies in Mechanical Engineering and Manufacturing). This tool has been created on an ad hoc basis to cover specific teaching requirements for some engineering courses, which would be difficult to implement on general educational platforms such as Moodle or Blackboard. PGDnet was essentially created as an online engineering problem‐solving tool. These exercises are checked and corrected automatically, providing students with their final and partial scores, and with the solutions to these various sections. A stochastic programming model selects different exercises each time that an activity is performed and attaches the tables, graphs, figures and annexes that are needed for their resolution in each case. As is common with these types of tools, PGDnet provides effective management of publication and delivery dates for the proposed work, and contains records and databases, which allow the stored information to be processed. Its main features include ease of use, reliability and great versatility as a specific tool in the area of technical university education.  相似文献