A novel Cervical Spine Protection device for reducing neck injuries in contact sports: design concepts and preliminary in vivo testing*     

Paolo Caravaggi  Alberto Leardini  Claudio Belvedere 《Sports biomechanics / International Society of Biomechanics in Sports》2020,19(3):382-394

Abstract

Head and neck injuries are common in contact sports such as American football. Different mechanisms can produce such injuries, including compressive impact forces on the crown of the helmet with the neck in a flexed chin-down position. The aim of this paper was developing and testing a novel Cervical Spine Protection Device (CSPD) designed to keep the neck within its safe physiological range. The cervical spine range of motion (ROM) of ten participants was measured under four conditions: free; wearing a football gear; wearing the CSPD; and wearing the CSPD underneath the gear. The CSPD was tested in terms of passive and active restraint of head motion, and for its capability to improve endurance time of the neck extensor muscles. Wearing the CSPD resulted in a significant 40–60% reduction in ROM across the three anatomical planes, and in increased endurance of the neck extensor muscles (FREE: 114 ± 57 s; CSPD: 214 ± 95 s; p = 0.004). In quasi-static loading conditions the CSPD was capable of keeping the neck within its physiological range, thus it may be used to decrease the risk of severe injuries due to dangerous chin-down positions.  相似文献   

Mechanical and EMG responses of the vastus lateralis and changes in biochemical variables to isokinetic exercise in endurance and power athletes     

Rainoldi A  Gazzoni M  Merletti R  Minetto MA 《Journal of sports sciences》2008,26(3):321-331

Twelve endurance athletes and six power athletes performed fatiguing isokinetic knee flexions/extensions. Isokinetic torque was recorded during the exercise. Isometric torque, cortisol and lactate responses, electromyographic (EMG) mean power frequency, average rectified value, and conduction velocity were analysed before and after the isokinetic exercise to determine correlations between electrophysiological variables and mechanical performances and/or blood concentrations of biomarkers in the two groups of athletes. The EMG variables were estimated from signals recorded from the vastus lateralis in both voluntary and electrically elicited isometric contractions. Power athletes recorded higher values than endurance athletes for the following variables: pre-exercise isometric maximal voluntary contraction (MVC), isokinetic MVC, rate of mechanical fatigue during isokinetic contractions, pre - post exercise variations and recovery times of conduction velocity and mean power frequency, and lactate concentrations. Moreover, conduction velocity overshooting was observed in endurance athletes during the recovery phase after exercise. The correlation analyses showed that the higher the rate of mechanical fatigue, the higher the lactate production and the reduction in conduction velocity due to the exercise.  相似文献   

The free-electron laser     

Alberto Renieri 《Endeavour》1984,8(1):35-43

The generation of coherent synchrotron radiation using beams of relativistic electrons passed through magnetic undulators opens up tremendous scope for photochemistry in general and isotopic separation by laser in particular. Applications for plasma heating in Tokamak-type installations to trigger off the controlled nuclear fusion process are also conceivable.  相似文献   

Private Higher Education and Diversity: An Exploratory Survey     

Pedro Teixeira  & Alberto Amaral 《Higher Education Quarterly》2001,55(4):359-395

In this preliminary review, the authors analyse the effects of privatisation on diversity in higher education (HE) systems by exploring the consequences of the establishment of HE Institutions by non-public organisations. The rising importance of privatisation in Europe (Western and transitional economies), Latin America, and Southeast Asia is analysed. Then follows detailed examinations of private-sector HE in countries representative of all these geographical areas to determine how far privatisation has stimulated diversity. The preliminary results indicate that in each case the private sub-sector has promoted limited and partial diversification. In general, though, the more recent private establishments, created to satisfy increasing demand for HE, have nonetheless focused predominately on teaching, have undertaken little, or no, research and appear to be of lower quality than the older institutions. The private sub-sector is characterised mostly by its low-risk behaviour, and a concentration on low-cost and/or safer initiatives. Public authorities must share at least a partial responsibility for some of the negative side effects of the development of private higher education.  相似文献   

In Pursuit of a Filipino Counselor Development Model: A Life-Span Approach     

Nino Jose Mateo  Jose Alberto S. Reyes 《International journal for the advancement of counseling》2015,37(3):262-278

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Global Citizenship and Global Universities. The Age of Global Interdependence and Cosmopolitanism     

Carlos Alberto Torres 《European Journal of Education》2015,50(3):262-279

This article focuses on the role of global universities and globalisations in an age of global interdependence and cosmopolitanism. Competing agendas that result from actions and reactions to multiple globalisations are considered in relation to global citizenship education. These agendas are crucial in understanding dilemmas of the local and the global in relation to education. Key emerging agendas are highlighted, including those of the hyperglobalisers, skeptics and transformationists. Three themes are central for this conversation, namely a) how multiple globalisations are impacting global life and academics, b) how networks have become privileged sites for global education, and c) the implications of globalisation and networks for global citizenship and global universities.  相似文献   

The questionable inventions of the clever Dr. Einstein     

Alberto A. Martínez 《Metascience》2014,23(1):49-55

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Learning Documentations in VET Systems: An Analysis of Current Swiss Practices     

Valentina Caruso  Alberto Cattaneo  Jean-Luc Gurtner 《Vocations and Learning》2016,9(2):227-256

Swiss vocational education and training (VET) is defined as a dual-track system where apprentices weekly alternate between vocational school and a (real) workplace. At the workplace, they have to keep a learning documentation throughout their training, in which they are expected to regularly document their professional development. The actual use of this documentation remains limited, however, and its potential for learning is clearly underexploited. The study presented in this paper sheds light on the current practices and issues related to the use of such a learning documentation in the Swiss VET system. Semi-structured interviews (N?=?29) were conducted with representatives of all the main actors of the Swiss VET system for various professional domains (Industrial & Handicraft, Commerce, and Health & Social Care). The study shows that although they all tend to see the potential of the learning documentation, the different actors of VET do not share a same conception of the aims and functions, both within and across professions. Based on their answers, possible improvements for this tool are discussed, and suggestions are made to enhance its use as a boundary object throughout the training.  相似文献   

Assessing Fit in Structural Equation Models: A Monte-Carlo Evaluation of RMSEA Versus SRMR Confidence Intervals and Tests of Close Fit     

Alberto Maydeu-Olivares  Dexin Shi  Yves Rosseel 《Structural equation modeling》2018,25(3):389-402

We compare the accuracy of confidence intervals (CIs) and tests of close fit based on the root mean square error of approximation (RMSEA) with those based on the standardized root mean square residual (SRMR). Investigations used normal and nonnormal data with models ranging from p = 10 to 60 observed variables. CIs and tests of close fit based on the SRMR are generally accurate across all conditions (even at p = 60 with nonnormal data). In contrast, CIs and tests of close fit based on the RMSEA are only accurate in small models. In larger models (p ≥ 30), they incorrectly suggest that models do not fit closely, particularly if sample size is less than 500.  相似文献   

The open method of coordination and the implementation of the Bologna process     

Amélia Veiga  Alberto Amaral 《Tertiary Education and Management》2006,12(4):283-295

In this paper the authors argue that the use of the Open Method of Coordination (OMC) in the implementation of the Bologna process presents coordination problems that do not allow for the full coherence of the results. As the process is quite complex, involving three different levels (European, national and local) and as the final actors in the implementation process higher education institutions (HEIs) have considerable degree of autonomy, assuming that the implementation of Bologna is a top–down linear policy implementation process does not account for the developments taking place, which produce implementation difficulties at several different levels. Constraints resulting from economic concerns at European and national levels may be an obstacle for the Bologna’s contribution to a social Europe.  相似文献