Effect of 6-weeks WBVT on the behaviour of the lower limb muscle fibres during vertical jumping     

Jacobo Ángel Rubio-Arias  Domingo Jesús Ramos-Campo  Paula Esteban  Fernando Martínez  José Fernando Jiménez 《Journal of sports sciences》2018,36(4):398-406

The purpose of the current study was to examine the effect of 6 weeks of whole body vibration training (WBVT) on body composition, muscle activity of the gastrocnemius and vastus lateralis, gastrocnemius muscle architecture (static and dynamic) and ground reaction forces (performance jump) during the take-off phase of a countermovement jump in young healthy adult males. A total of 33 men (23.31 ± 5.62 years) were randomly assigned to a whole body vibration group (experimental group, EG_WBVT: n = 17; 22.11 ± 4.97 years) or a control group (CG: n = 16; 24.5 ± 6.27 years). The total duration of the intervention phase (WBVT) was 6 weeks with a frequency of 3 sessions per week. Statistically significant differences were observed (P ≤ 0.05) between pre- and post-test in the power peak (Δ 1.91 W · kg^?1; P = 0.001), take-off velocity (0.1 cm · s^?1; P = 0.002) and jump height (Δ 0.4 cm; P = 0.002) for EG_WBVT. There were no statistically significant differences in any of the body composition and muscle architecture variables. Moreover, no significant differences were found between EG_WBVT and CG nor changes in muscle activity during take-off phase of the gastrocnemius and vastus lateralis pre- versus post-training. This study suggests that a 6-week WBVT programme with increasing intensity improves jump performance but does not alter muscle activity nor muscle architecture in healthy young men.  相似文献   

Nature of green advertisements in India: Are they greenwashed?     

Angeline Gautami Fernando  Bharadhwaj Sivakumaran  L. Suganthi 《亚洲交流杂志》2013,23(3):222-241

This study performs a systematic content analysis of Indian English green print advertisements for the years 2010 and 2011 to verify if greenwashing is prevalent. Green advertisements were analysed based on four dimensions – (1) claim specificity, (2) greenwashing category, (3) incidence of associative claims and (4) presence of certifications. The results indicate that 51.7% of the claims were greenwashed and most of them were vague or ambiguous (37.7%). Most claims lacked specificity (67.0%) and image claims (60.0%) were widely used. Very few advertisements (3.3%) employed certifications to substantiate their claims. Interestingly, we also found that more than half of the image-related claims (55.8%) were categorized as misleading and highly specific claims were considered acceptable. We suggest that either the self-regulatory body – the Advertising Standards Council of India – or the legal regulatory framework accommodate well-defined provisions for regulating green claims in advertisements to curb greenwashing.  相似文献   

An Examination of Coursera as an Information Environment: Does Coursera Fulfill its Mission to Provide Open Education to All?     

Samantha Audsley  Kalyani Fernando  Brittany Robinson  Katie Varney 《期刊图书馆员》2013,64(2):136-166

In terms of international education, the concept of online education seems to be a growing trend. Edxonline.org, Minervaproject.com, and Udacity.com are all new massive online open courses (MOOCs)—education websites similar to Coursera offering students the ability to receive the best education from elite universities entirely online. The most tantalizing promise of a company like Coursera is the role it might play in improving education for the world's have-nots: high school dropouts, the global poor, and those less able to self-teach.  相似文献   

Relationship between exchange block time in swim starts and final performance in relay races in international championships     

Jose M. Saavedra  Antonio García-Hermoso  Yolanda Escalante  Ana M. Dominguez  Raul Arellano  Fernando Navarro 《Journal of sports sciences》2013,31(19):1783-1789

Abstract

The purpose of this study was to investigate the association between relay exchange block time and final performance in 4 × 100-m and 4 × 200-m freestyle and 4 × 100-m medley relays as a function of sex (men and women) and classification (medallists and non-medallists) in international competitions. Nineteen international competitions covering a 13-year period (2000–2012) were analysed retrospectively. The data corresponded to a total of 827 team relay histories (407 men, 420 women). Kruskal–Wallis and Mann–Whitney tests were performed to determine any differences by sex, classification, and event. Similarly, the relationship between the exchange block times and final performance was examined by means of a Pearson correlation analysis. In the three events, the men’s exchange block times were shorter than those of the women (η² = 0.049–0.109; P < 0.001). The exchange block time was especially relevant for the women’s relay medallists in the 4 × 100-m freestyle (r = 0.306, P = 0.021) and 4 × 100-m medley (r = 0.385, P = 0.011), while for men the relationship was clearer for the non-medallists. These results suggest that the exchange block time should be considered as one of the performance parameters of swimming relay starts, and thus should be included explicitly as part of training. In particular, the coach could design training targeted at standardising an optimal exchange block time equal to or less than that expected for other teams in the competition.  相似文献   

Effects of cigarette smoking on cardiac autonomic function during dynamic exercise     

Goncalo V. Mendonca  Fernando D. Pereira  Bo Fernhall 《Journal of sports sciences》2013,31(9):879-886

Abstract

The purpose of this study was to investigate the acute effect of cigarette smoking on cardiac autonomic function in young adult smokers during dynamic exercise. Fourteen healthy young smokers (21.4 ± 3.4 years) performed peak and submaximal exercise protocols under control and smoking conditions. Resting and submaximal beat-to-beat R-R series were recorded and spectrally decomposed using the fast Fourier transformation. Smoking resulted in a significant decrease in work time, [Vdot]O_2peak and peak O₂ pulse (P < 0.05). Heart rate increased at rest and during submaximal exercise after smoking (P < 0.05). The raw high frequency and low frequency power were significantly reduced by smoking, both at rest and during exercise (P < 0.05). The low to high frequency ratio was higher after smoking (P < 0.05). The normalised low frequency power was also significantly increased by smoking, but only at rest (P < 0.05). These data demonstrate that the tachycardic effect elicited by smoking is accompanied by acute changes in heart rate spectral components both at rest and during exercise. Therefore, the cardiac autonomic control is altered by smoking not only at rest, but also during exercise, resulting in reduced vagal modulation and increased sympathetic dominance.  相似文献   

Latin American Theology and Religious Pluralism: A Latin American Voice     

Fernando A. Cascante-Gómez 《Religious education (Chicago, Ill.)》2013,108(5):556-563

This article summarizes recent efforts by Latin-American theologians concerned with developing a pluralist theology of liberation. The author highlights some of the most significant issues and themes of this emerging theological reflection among liberation theologians. Finally, he identifies some of the challenges a pluralist theology of liberation raises for our task as religious educators in North America.  相似文献   

Science Learning: A path analysis of its links with reading comprehension,question-asking in class and science achievement     

Francisco Cano  Ángela García  A.B.G. Berbén  Fernando Justicia 《International Journal of Science Education》2013,35(10):1710-1732

The purpose of this research was to build and test a conceptual model of the complex interrelationships between students' learning in science (learning approaches and self-regulation), their reading comprehension, question-asking in class and science achievement. These variables were measured by means of a test and a series of questionnaires administered to 604 ninth-grade students, and the data collected were analysed using a correlational, cross-sectional design. Results of a path analysis indicated that (a) students’ self-regulated and intentional knowledge-constructing activity (self-regulated strategy use, deep approach and knowledge-building) were what chiefly accounted for their question-asking in class; (b) question-asking (high and low levels) was related directly to reading comprehension and indirectly, through its contribution to the this, to academic achievement; (c) reading comprehension was directly and negatively associated with surface approach and indirectly and positively related to deep approach and knowledge-building; and (d) some of these variables, particularly reading comprehension, accounted for academic achievement in science. This model explained nearly 30% of the variance in academic achievement and provided a substantial and distinctive insight into the web of interrelationships among these variables. Implications for future research and science teaching and learning are discussed (e.g. the importance of supporting students' efforts to learn science in a meaningful, active and self-regulated way and of improving their reading comprehension).  相似文献   

The relationship between teacher’s autonomy support and students’ autonomy and vitality     

Juan L. Núñez  Celia Fernández  Fernando Grijalvo 《Teachers and Teaching》2013,19(2):191-202

Abstract

Within education, some teachers’ interpretation of professionalism emphasizes conformity to the perceived norms of collective associations. Unprofessional behaviour, often equated with ‘unethical’ behaviour, is seen by many to be that which threatens solidarity and loyalty to colleagues. Informal norms typified by casual collegial relations as well as more formal attachments to organized unions or teachers’ federations exert a significant influence on individuals’ behaviour within the group. Professional ethics, in this sense, become concerned primarily with how one relates to colleagues rather than how one fulfils moral responsibilities to students. Qualitative findings from interviews with elementary and secondary school teachers suggest that, as a result of an ethic of collegial loyalty, some teachers experience personal moral and ethical dilemmas that they find difficult to resolve. Some respondents acknowledged that this can enable serious situations to be ignored or ‘covered up’. This paper examines some of the tensions and dilemmas experienced by teachers and raises questions about the ethical adequacy of defining professionalism in terms of inter‐colleague behaviour.  相似文献   

Agents control in intelligent learning systems: The case of reactive characteristics     

Ana Lilia Laureano-Cruces  Javier Ramírez-Rodríguez  Fernando de Arriaga  Rafael Escarela-Pérez 《Interactive Learning Environments》2013,21(2):95-118

Intelligent learning systems (ILSs) have evolved in the last few years basically because of influences received from multi-agent architectures (MAs). Conflict resolution among agents has been a very important problem for multi-agent systems, with specific features in the case of ILSs. The literature shows that ILSs with cognitive or pedagogical agents are prone to arbitration methods, where as ILSs with reactive agents are much in favor of control mechanisms. For these kind of systems, different control types are proposed based on the different stimuli that these agents will receive. These stimuli are aspects to be evaluated during the teaching/learning process such as: (1) error analysis, (2) learning styles, (3) analogies, (4) social aspects, etc.

The paper reviews several ILSs, related to our work; different control mechanisms are proposed to solve the agents' intervention conflicts. Finally, the use of several mechanisms is exemplified by the results of a specific ILS.  相似文献   

Granite desalination using electromigration. Influence of type of granite and saline contaminant     

Jorge Feijoo  Xosé Ramón Nóvoa  Teresa Rivas  María Jesús Mosquera  Javier Taboada  Cristina Montojo  Fernando Carrera 《Journal of Cultural Heritage》2013,14(5):365-376

We describe the results of electromigration desalination of two soluble salt-contaminated Galician granites. The efficacy of electromigration, which had not been previously applied to granite, was assessed for two types of granite contaminated with a 20% NaCl solution and seawater. Desalination effectiveness was evaluated as follows: (1) analysis of anode and cathode ion content during testing; (2) analysis of ions at different distances from the electrodes after testing; (3) pH assessment of the stone surfaces; and (4) evaluation of colour changes. Results were very satisfactory; by the end of testing, chloride was reduced by almost 100% in both the NaCl and seawater contaminated samples. Sulfate reduction was also significant, despite this ion's lower mobility. The granite pH values remained close to neutral and colour changes were minimal. The difference in effectiveness of the process for the two types of stone was associated with their dissimilar pore structure.  相似文献