Predictive value of ventilatory inflection points determined under field conditions     

Christian Heyde  Hubert Mahler  Kai Roecker  Albert Gollhofer 《Journal of sports sciences》2016,34(9):787-793

The aim of this study was to evaluate the predictive potential provided by two ventilatory inflection points (VIP₁ and VIP₂) examined in field without using gas analysis systems and uncomfortable facemasks. A calibrated respiratory inductance plethysmograph (RIP) and a computerised routine were utilised, respectively, to derive ventilation and to detect VIP₁ and VIP₂ during a standardised field ramp test on a 400 m running track on 81 participants. In addition, average running speed of a competitive 1000 m run (S_1k) was observed as criterion. The predictive value of running speed at VIP₁ (S_VIP1) and the speed range between VIP₁ and VIP₂ in relation to VIP₂ (VIP_SPAN) was analysed via regression analysis. VIP_SPAN rather than running speed at VIP₂ (S_VIP2) was operationalised as a predictor to consider the covariance between S_VIP1 and S_VIP2. S_VIP1 and VIP_SPAN, respectively, provided 58.9% and 22.9% of explained variance in regard to S_1k. Considering covariance, the timing of two ventilatory inflection points provides predictive value in regard to a competitive 1000 m run. This is the first study to apply computerised detection of ventilatory inflection points in a field setting independent on measurements of the respiratory gas exchange and without using any facemasks.  相似文献   

What makes a skilled writer? Working memory and audience awareness during text composition     

Denis Alamargot  Gilles Caporossi  David Chesnet  Christine Ros 《Learning and individual differences》2011,21(5):505-516

This study investigated the role of working memory capacity as a factor for individual differences in the ability to compose a text with communicative efficiency based on audience awareness. We analyzed its differential effects on the dynamics of the writing processes, as well as on the content of the finished product. Twenty-five graduate students composed a procedural text explaining how to assemble a model turbine. They were free to consult a documentary source, featuring captioned pictures of turbine parts and assembly steps, at any time. Graphomotor and eye movements were recorded using ‘Eye and Pen’ software with an eye-tracker and digitizing tablet. Results showed that high WM capacity writers used a different strategy to explore the visual source, making longer writing pauses and producing more detailed procedures, and achieved the communicative goal more efficiently, by introducing more reader supports. In conclusion, we discuss the feasibility of audience awareness training.  相似文献   

With Tools and Strategies Teachers Use in Online Courses： A Mexican Public University Case     

Lewis McAnally-Salas Erika Judith Espinosa-Gomez Gilles Lavigne 《美中教育评论》2011,(3):276-287

The rapid development of ICT （information technology and communication） in the last two decades has changed society substantially as a whole. For higher education institutions, the external environment pressure to incorporate ICT in their educational and administrative processes has forced them to invest in resources for infrastructure and training. In addition, teachers have found that they can use technology in their teaching, but lack of full knowledge of how to use it effectively from a pedagogical point of view. The incorporation of new education modalities depends largely on the contextual variables prevailing in the institution and teachers. In UABC （Autonomous University of Baja California）, the early days of online education go hack to 1996, so the study period was from 1996 to 2009. An online survey was designed to fmd out the teachers＇ backgrounds and involvement in online education, their experience as online teachers, and the tools and practices used. Of 97 teachers who were identified with some experience in online teaching, 70% responded to the Survey （68）. It was found that the highest percentage （33%） of teachers who responded the survey started teaching online between 2003 and 2006. 56% of teachers have been teaching between one and five online courses. On the other hand, most teachers recognized that 30%-79% of the content of their courses were online based. The most popular learning management system used is moodle followed by blackboard in teachers＇ preference. In general, teachers expressed using the three main communication tools of online education： forums, chat and e-mail, favoring the use of e-mail. The communication slrategies teachers often use in their courses promoted student-student and student-teacher interaction. In their evaluation strategies, most said that they used self-assessment, rubrics and to a lesser extent online exams and co-evaluation. The results show that most teachers who have been involved in online education in UABC campus have expressed havi  相似文献   

A partitioning technique for defining instructional groups     

Frank B. Baker  Lawrence J. Hubert 《Instructional Science》1979,8(2):121-132

A technique is presented for partitioning N students into K groups of fixed sizes using a given measure of proximity for all student pairs. The measure of proximity is typically calculated from a set of variables, such as completed curriculum units or learning style, and constitutes the data needed for a criterion of partition fit. This latter index is explicitly defined by the sum of within-group proximities and when used in conjunction with the optimization procedure discussed, homogeneous groups can be obtained that satisfy externally imposed size requirements. Finally, a simple generalization is suggested for the related task of grouping students to meet upper limit size constraints only.  相似文献   

Techniques used in high-scoring and low-scoring 'Roche' vaults performed by elite male gymnasts     

Takei Y  Dunn JH  Blucker E 《Sports biomechanics / International Society of Biomechanics in Sports》2003,2(2):141-162

The 16 highest-scored Roche vaults (G1) performed during the 2000 Olympic Games were compared with those receiving the 16 lowest-scores (G2). A 16-mm motion picture camera operating at 100 Hz recorded the vaults during the competition. The results of t tests (p < .05) indicated G1, compared to G2, had (a) shorter time of board support, greater normalised average upward vertical force and backward horizontal force exerted by the board, greater change in the vertical velocity while on the board, and greater vertical velocity at board take-off, (b) comparable linear and angular motions in pre-flight, (c) smaller backward horizontal impulse exerted by the horse, smaller loss of the horizontal velocity while on the horse, and greater horizontal and vertical velocities at horse take-off, (d) greater height and larger horizontal distance of post-flight, (e) higher body mass centre at knee release, and (f) higher mass centre, greater normalised moment of inertia, and smaller vertical velocity at mat touchdown. Therefore, gymnasts and coaches should focus on sprinting the approach; blocking and pushing-off the take-off board rapidly and vigorously; departing the board with a large vertical velocity; exerting large downward vertical force and small forward horizontal force from the hand-stand position while on the horse; departing the horse with large horizontal and vertical velocities; and completing the majority of the double salto forward near the peak of trajectory and releasing the knees above the top of the horse to prepare for a controlled landing.  相似文献   

Integrated science education in African primary schools     

Hubert M. Dyasi 《Prospects》1974,4(1):63-71

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Kinematic,kinetic and EMG analysis of four front crawl flip turn techniques     

Suzana Matheus Pereira  Caroline Ruschel  Marcel Hubert  Leandro Machado  Helio Roesler  Ricardo Jorge Fernandes 《Journal of sports sciences》2015,33(19):2006-2015

This study aimed to analyse the kinematic, kinetic and electromyographic characteristics of four front crawl flip turn technique variants. The variants distinguished from each other by differences in body position (i.e. dorsal, lateral, ventral) during rolling, wall support, pushing and gliding phases. Seventeen highly trained swimmers (17.9 ± 3.2 years old) participated in interventional sessions and performed three trials of each variant, being monitored with a 3-D video system, a force platform and an electromyography (EMG) system. Studied variables: rolling time and distance, wall support time, push-off time, peak force and horizontal impulse at wall support and push-off, centre of mass horizontal velocity at the end of the push-off, gliding time, centre of mass depth, distance, average and final velocity during gliding, total turn time and electrical activity of Gastrocnemius Medialis, Tibialis Anterior, Biceps Femoris and Vastus Lateralis muscles. Depending on the variant, total turn time ranged from 2.37 ± 0.32 to 2.43 ± 0.33 s, push-off force from 1.86 ± 0.33 to 1.92 ± 0.26 BW and centre of mass velocity during gliding from 1.78 ± 0.21 to 1.94 ± 0.22 m · s^?1. The variants were not distinguishable in terms of kinematical, kinetic and EMG parameters during the rolling, wall support, pushing and gliding phases.  相似文献   

Head injury secondary to suspected child maltreatment: results of a prospective Canadian national surveillance program     

Bennett S  Ward M  Moreau K  Fortin G  King J  Mackay M  Plint A 《Child abuse & neglect》2011,35(11):930-936

Objective

We sought to determine the incidence, clinical features, and demographic profile of head injury secondary to suspected child maltreatment (abuse or neglect) in Canada to help inform the development and evaluation of prevention programs for abusive head injuries.

Methods

From March 1, 2005 to February 28, 2008, an average of 2,545 paediatricians and paediatric subspecialists were surveyed monthly through the established network of the Canadian Paediatric Surveillance Program. We calculated incidence rates using the number of confirmed cases over the product of the duration of the study (3 years) and population estimates by age group.

Results

There were 220 confirmed cases of head injury from suspected child maltreatment. The annual incidence rate was 14.1 per 100,000 for children less than 1 year of age and 1.4 per 100,000 for those less than 15 years. Seventy three percent (141) of cases involved infants less than 12 months of age and 52% (100) of cases involved infants less than 6 months of age. Seventy-five percent (165) of cases presented to the emergency room. With regard to outcome, 12% (27) of cases resulted in death and 45% (75) of survivors had neurological sequelae at discharge. Thirty percent (67) of all cases, as well as 30% (8) of deaths were previously known to child welfare authorities.

Conclusion

This study provides an estimate of the rate of head injury secondary to suspected child maltreatment in Canada. The young age and poor medical outcomes of those involved highlights the need for prevention efforts that are implemented early in life. Given that a significant percentage of injured infants and children were already known to child welfare authorities, the study also highlights the need to establish and evaluate additional preventive efforts for parents and caregivers already in the child welfare system.  相似文献   

Fusing different information retrieval systems according to query-topics: a study based on correlation in information retrieval systems and TREC topics     

Anthony Bigot  Claude Chrisment  Taoufiq Dkaki  Gilles Hubert  Josiane Mothe 《Information Retrieval》2011,14(6):617-648

To evaluate Information Retrieval Systems on their effectiveness, evaluation programs such as TREC offer a rigorous methodology as well as benchmark collections. Whatever the evaluation collection used, effectiveness is generally considered globally, averaging the results over a set of information needs. As a result, the variability of system performance is hidden as the similarities and differences from one system to another are averaged. Moreover, the topics on which a given system succeeds or fails are left unknown. In this paper we propose an approach based on data analysis methods (correspondence analysis and clustering) to discover correlations between systems and to find trends in topic/system correlations. We show that it is possible to cluster topics and systems according to system performance on these topics, some system clusters being better on some topics. Finally, we propose a new method to consider complementary systems as based on their performances which can be applied for example in the case of repeated queries. We consider the system profile based on the similarity of the set of TREC topics on which systems achieve similar levels of performance. We show that this method is effective when using the TREC ad hoc collection.  相似文献   

通过探究学习,儿童能得到些什么     

Hubert Dyasi  李志厚 《中国教师》2010,(11):29-30

好奇心是人类的基本特征。通过评价学习的自然规律,探究过程可以给儿童在形成和保持新的世界观方面所需要的直接反馈和个人经验。这些观点可以简化为:探究怎样才能使儿童在获得和理解科学概念的方式上有所不同?  相似文献