Physiological determinants of speciality of elite middle- and long-distance runners     

Rabadán M  Díaz V  Calderón FJ  Benito PJ  Peinado AB  Maffulli N 《Journal of sports sciences》2011,29(9):975-982

The aim of this study was to determine which physiological variables predict excellence in middle- and long-distance runners. Forty middle-distance runners (age 23 ± 4 years, body mass 67.2 ± 5.9 kg, stature 1.80 ± 0.05 m, VO(2max) 65.9 ± 4.5 ml · kg(-1) · min(-1)) and 32 long-distance runners (age 25 ± 4 years, body mass 59.8 ± 5.1 kg, stature 1.73 ± 0.06 m, VO(2max) 71.6 ± 5.0 ml · kg(-1) · min(-1)) competing at international standard performed an incremental running test to exhaustion. Expired gas analysis was performed breath-by-breath and maximum oxygen uptake (VO(2max)) and two ventilatory thresholds (VT(1) and VT(2)) were calculated. Long-distance runners presented a higher VO(2max) than middle-distance runners when expressed relative to body mass (P < 0.001, d = 1.18, 95% CI [0.68, 1.68]). At the intensities corresponding to VT(1) and VT(2), long-distance runners showed higher values for VO(2) expressed relative to body mass or %VO(2max), speed and oxygen cost of running (P < 0.05). When oxygen uptake was adjusted for body mass, differences between groups were consistent. Logistic binary regression analysis showed that VO(2max) (expressed as l · min(-1) and ml · kg(-1) · min(-1)), VO(2VT2) (expressed as ml · kg(-0.94) · min(-1)), and speed at VT(2) (v(VT2)) categorized long-distance runners. In addition, the multivariate model correctly classified 84.7% of the athletes. Thus, VO(2max), VO(2VT2), and v(VT2) discriminate between elite middle-distance and long-distance runners.  相似文献   

Anticipatory strategies of team-handball goalkeepers     

Gutierrez-Davila M  Rojas FJ  Ortega M  Campos J  Parraga J 《Journal of sports sciences》2011,29(12):1321-1328

This study seeks to discover whether handball goalkeepers employ a general anticipatory strategy when facing long distance throws and the effect of uncertainty on these strategies. Seven goalkeepers and four throwers took part. We used a force platform to analyse the goalkeeper's movements on the basis of reaction forces and two video cameras synchronised at 500 Hz to film the throw using 3D video techniques. The goalkeepers initiated their movement towards the side of the throw 193 ± 67 ms before the release of the ball and when the uncertainty was reduced the time increased to 349 ± 71 ms. The kinematics analysis of their centre of mass indicated that there was an anticipatory strategy of movement with certain modifications when there was greater uncertainty. All the average scores referring to velocity and lateral movement of the goalkeeper's centre of mass are significantly greater than those recorded for the experimental situation with bigger uncertainty. The methodology used has enabled us to tackle the study of anticipation from an analysis of the movement used by goalkeepers to save the ball.  相似文献   

Assessment of muscle fatigue after an ultra-endurance triathlon using tensiomyography (TMG)     

García-Manso JM  Rodríguez-Ruiz D  Rodríguez-Matoso D  de Saa Y  Sarmiento S  Quiroga M 《Journal of sports sciences》2011,29(6):619-625

In this study, we used tensiomyography (TMG) to assess muscle status immediately after an ultra-endurance triathlon. Maximal radial displacement or deformation of the muscle belly, contraction time, delay time, sustain time, and relaxation time were measured for both legs, and dependent t-tests were used to compare means between the beginning and end of the race. The 19 men assessed (age 37.9 ± 7.1 years; height 177.5 ± 4.6 cm; weight: 73.6 ± 6.5 kg) participated in the 2009 edition of the Lanzarote Ironman. Deterioration in the neural response was observed for contraction time (P = 0.008) and relaxation time (P = 0.011), with a moderate decrease in the response time (sustain time) and a loss in muscle stiffness (deformation of the muscle belly). The effect of muscle fatigue on the rectus femoris and biceps femoris was different. Barely any changes in contraction time, relaxation time, sustain time, and deformation of the muscle belly were observed, while only the contraction response time decreased to a significant extent (reduction in delay time; P = 0.003). The considerable loss in contractile capacity induced by a long-distance race was reflected in changes in the neuromuscular response and fluctuations in the contractile capacity of the muscle. These modifications, derived from a prolonged, exhausting effort, can be assessed in a simple, non-aggressive, non-invasive way using tensiomyography.  相似文献   

Private Returns to an University Education: An Instrumental Variables Approach     

Manuel Salas-Velasco 《Higher Education》2006,51(3):411-438

This article examines the determinants of the salaries that Spanish university graduates earn on the labor market. Different earnings equations are estimated that allow us to measure the economic returns to investment in human capital at the university level, demonstrating that: on the one hand, considering schooling to be an exogenous variable gives a downward bias to the estimations of the private rates of return to an university education; on the other hand, not taking into account the aspects of the demand-side of the labor market in the traditional Mincerian earnings function, even though schooling is considered as an endogenous variable, the rates of return estimated for an university education would be given an upward bias. The problem concerning the endogeneity of schooling has been corrected in this article by using the instrumental variables technique.  相似文献   

Students' personal networks in virtual and personal learning environments: a case study in higher education using learning analytics approach     

Oskar Casquero  Ramón Ovelar  Jesús Romo  Manuel Benito  Mikel Alberdi 《Interactive Learning Environments》2016,24(1):49-67

The main objective of this paper is to analyse the effect of the affordances of a virtual learning environment and a personal learning environment (PLE) in the configuration of the students' personal networks in a higher education context. The results are discussed in light of the adaptation of the students to the learning network made up by two undergraduate, inter-university and online courses. Besides, we also examine the influence of this effect in the learning process. The findings reflect the effectiveness of a PLE for facilitating student participation and for assisting students in the creation of larger and more balanced personal networks with richer social capital. However, the findings do not provide evidences about a difference in the learning performance between the two environments. From a methodological point of view, this paper serves as an illustration of the analysis of personal networks on digital data collected from technology-enhanced learning environments.  相似文献   

The management of austerity in higher education: an international comparison     

Manuel Crespo  With the collaboration of Mohammadine Ouardi 《Higher Education》1989,18(4):373-395

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Schooling of Children with Rare Diseases and Disability in Europe     

Renata Linertová  Javier González-Guadarrama  Pedro Serrano-Aguilar  Manuel Posada-De-la-Paz  Márta Péntek  Georgi Iskrov 《International Journal of Disability, Development & Education》2019,66(4):362-373

ABSTRACT

Inclusive education of disabled students has been promoted in European disability policies. However, the transition process from more segregated system is slow. The purpose of this study was to provide an insight about different types of schooling of disabled children affected by a rare disease across Europe and to evaluate their and caregivers’ well-being. We analysed data from a cross-sectional study (BURQOL-RD) of persons with rare diseases that cause intellectual and/or physical disability: Prader-Willi syndrome, fragile X syndrome, three types of mucopolysaccharidosis and Duchenne muscular dystrophy. The sample consisted of 359 children aged 6–17 and 269 caregivers from eight European countries. Results showed differences between countries in proportion of students placed in special schools, which are still valid option in countries such as Germany, France or UK. Within the inclusive education modalities, lack of special support for disabled students was observed especially in low-income countries. No association between the type of schooling and quality of life was observed, but the subjective caregivers’ burden seems to be higher in special schools. The study shows existent differences in implementation of inclusive education in Europe. More research is needed in the field of rare disease disability and educational needs.  相似文献   

Access to post‐compulsory education and training: economic,sociological and political determinants and remaining research gaps     

Manuel Souto Otero 《比较教育学》2007,43(4):571-586

This paper presents a review and assessment of existing theoretical accounts to explain differentials in access to education and training in advanced economies. These theories tend to focus on the analysis of the influence of a set of economic, sociological and political variables on access to education. Existing theories are criticized on two grounds. Firstly, they seldom take into consideration the crucial role of political‐institutional factors, and in particular, welfare states’ actions through direct investment and regulation in shaping access levels. Secondly, they focus narrowly on the analysis of different stages of education and training, and this does not reflect the current policy emphasis on lifelong learning. The paper concludes with an outline of a future research agenda to address these gaps, and also calls for a more rigorous analysis of the weight of the different factors affecting access.  相似文献   

Science–technology flows in Spanish regions: An analysis of scientific citations in patents     

Manuel Acosta  Daniel Coronado 《Research Policy》2003,32(10):1783-1803

Many regions of the European Union with a high degree of autonomy have elected very clearly to stimulate scientific research and technological development (R&D) as a specific means of promoting economic growth and the welfare of their citizens. In Spain, several autonomous regions have organised their efforts in science and technology by means of the adoption of regional R&D plans. In some cases, particular concern is taken to link the scope of scientific research with that of technology, but even in these few cases, it is acknowledged that little is known of the mechanisms by which the results of scientific research are translated into technological development, and how this latter in turn influences the objectives of scientific research. Our aim in this article is to study in greater depth the relationship between science and technological development in the various regions of Spain. The methodology that we apply to investigate the links between science and technology is based on an analysis of scientific citations in patent documents (non-patent citation (NPC)). The results obtained from this study provide some relevant data on the interconnection between the scientific and technological systems from a regional perspective.  相似文献   

Portuguese science teachers' education,attitudes, and practice relative to the issue of alternative conceptions     

Manuel Sequeira  Laurinda Leite  Maria da Conceio Duarte 《科学教学研究杂志》1993,30(8):845-856

Many studies have shown that students of all school levels hold alternative conceptions that differ from the scientific conceptions transmitted by the school. These results raise some questions about the efficacy of traditional teaching and stress the need for using teaching strategies that explicitly take into account the alternative conceptions that students bring to the science classes. This issue has recently been raised and widely discussed throughout Portugal and the proposals for the new science syllabuses advise teachers to take it into account. However, the number of studies investigating both the teachers' attitudes towards this issue and the use of teaching strategies based on students' alternative conceptions is very limited. This article aims to present the results obtained from science teachers about their attitudes towards students' alternative conceptions and the use of teaching strategies based on these conceptions. The results may contribute to the planning of in-service courses.  相似文献