Benefits of achieving vigorous as well as moderate physical activity recommendations: Evidence from heart rate complexity and cardiac vagal modulation

Abstract

The aim of this study was to examine differences in traditional heart rate variability measurements and heart rate complexity (sample entropy) in young adults grouped by objectively measured achievement of either moderate or both moderate and vigorous physical activity recommendations. Of 168 young adults tested (86 females, 82 males; age 20.5 ± 1.2 years), 119 achieved only recommendations for moderate physical activity (moderate group) and 49 achieved recommendations for both moderate and vigorous physical activity (vigorous group). Analysis of covariance controlling for sex, weekly minutes of moderate physical activity, and percentage of body fat was used to assess between-group differences in heart rate variability and heart rate complexity. Logistic regression analysis was used to determine the group characteristics that best predicted high heart rate complexity and vagal indices of heart rate variability. The majority of the autonomic measures were higher (P < 0.05) in the vigorous group, and regression analysis showed that vigorous physical activity was the only multivariate predictor of higher heart rate complexity and higher heart rate variability. Young adults engaged in regular vigorous physical activity were more than twice as likely to have high heart rate complexity than those involved in predominantly moderate exercise. These findings suggest that vigorous physical activity is more closely associated with high heart rate complexity than moderate physical activity in young adults.     

Effects of volleyball match-induced fatigue on knee joint position sense

Abstract

It has been suggested that a greater number of injuries during the last third of practice sessions or matches could be related to alteration of lower limb neuromuscular control due to neuromuscular fatigue. This fatigue-related effect can be mediated by changes in joint proprioception. In athletes, the use of functional fatigue protocols could have the advantage of mimicking the demands of sporting activity, thus reflecting more specifically the changes in neuromuscular control and proprioception observed in sport settings. The purpose of the present study was to assess the effect of fatigue induced by a volleyball match on knee joint position sense in elite volleyball players. Seventeen female volleyball players aged 18.9±4.2 years from the Portuguese national team volunteered for the study. Knee joint position sense was evaluated by an open kinetic chain technique and active knee positioning, and was reported using absolute, relative, and variable angular errors. Joint position sense measures were obtained before and immediately after a simulated volleyball match of five sets. To ensure that the match was sufficiently intense to induce fatigue, the perceived exertion or exercise intensity was assessed at the end of the match using Borg’ s rating of perceived exertion (RPE) scale. All participants completed the volleyball match (90min duration), reaching or exceeding 15 on the RPE scale (15.59±0.71; range 15–17), equivalent to “hard/heavy work”. After the volleyball match, a significant increase in absolute (2.11°) and relative (1.71°) angular errors was detected. Match-induced fatigue significantly exacerbated the overestimation of the test position. Moreover, the reliability and accuracy in estimating knee angles decreased from rest to the fatigued state, as shown by the increase (264%) in variable error. Our results show that fatigue induced by a volleyball match has a marked effect on knee joint position sense in elite female volleyball players. Knee joint position sense was less accurate and less consistent after the volleyball match. Fatigue induced by a simulated competitive volleyball match resulted in proprioceptive deficits, decreasing sensorimotor system acuity in female volleyball players.     

Exploring the uses of mobile phones to support informal learning

This paper explores how a group of undergraduate students in the United Arab Emirates (UAE) use their mobile phones to perform informal learning activities related to the content of their courses outside the classroom. The paper also addresses the usefulness of informal learning activities to support students’ learning. The study adopts an exploratory case study design and uses multiple methods of data collection including questionnaires, interviews and diary entries. Main findings suggest that students performed informal learning activities mostly from home, interacting mainly with classmates. It also shows that students were in control of their informal learning activities without teachers’ input. However, it was found that students used only a limited number of applications but these were considered useful to their learning. The paper contributes to a discussion of the implications of training and instructor support to help students to take more advantage of mobile phone applications to support informal learning. Recommendations for further research are discussed.     

Near-peer teaching in an anatomy course with a low faculty-to-student ratio

Near-peer teaching is an educational format which utilizes tutors who are more advanced in a curriculum's content to supervise students' activities and to act as instructors in laboratory settings. This format is often used in anatomy laboratory courses. The goal of the present study is to describe the design and implementation of near-peer teaching in an anatomy course and to evaluate students' perceptions of the program. A total of 700 students were registered for this anatomy course which employed near-peer instructors. Of enrolled students, 558 (79.7%) agreed to participate in this study. In general, the practical section (e.g., the clinical hour, image-based anatomy session, and gross anatomy laboratory) of the course was viewed more favorably compared to the theory section (54.8%, n = 306), with dissection and prosection in the laboratory rated as the most valued experiences (34.9%, n = 195). Near-peer teaching is a viable option that satisfies the demands of modern curricula using small groups. This format stimulates learning within courses that have large numbers of students and low faculty-to-student ratios.     

国际体育纠纷的种类、国际体育仲裁的特殊性和必要性及解决途径

摘要：生活中必有冲突,如何解决这些冲突是问题的关键所在。体育纠纷具有特殊性,通过体育共同体以外的方法来解决体育纠纷,可能出现矛盾的裁决、不公平以及法律的不确定性,这些都影响到裁决的有效性、效力和案件裁决的执行。国际体育仲裁院正是基于此背景下建立的,它独立于任何体育组织或地方政府的独立机构。它通过那些适用于体育领域特殊需要的程序规则以仲裁和调解的方式来解决与体育相关的纠纷,也逐渐成为最公正、最有效、最快速、最具成本效益的体育纠纷解决模式。     

Isokinetic hamstrings-to-quadriceps peak torque ratio: the influence of sport modality, gender, and angular velocity

The purpose of this study was to determine differences in hamstrings-to-quadriceps (H/Q) peak torque ratios evaluated at different angular velocities between men and women who participate in judo, handball or soccer. A total of 166 athletes, including 58 judokas (26 females and 32 males), 39 handball players (22 females and 17 males), and 69 soccer players (17 females and 52 males), were evaluated using an isokinetic dynamometer. The H/Q isokinetic peak torque ratios were calculated at angular velocities of 1.05 rad · s?1 and 5.23 rad · s?1. In the analysis by gender, female soccer players produced lower H/Q peak torque ratios at 1.05 rad · s?1 than males involved in the same sport. However, when H/Q peak torque ratio was assessed at 5.23 rad · s?1, there were no significant differences between the sexes. In the analysis by sport, there were no differences among females at 1.05 rad · s?1. In contrast, male soccer players had significantly higher H/Q peak torque ratios than judokas (66 ± 12% vs. 57 ± 14%, respectively). Female handball players produced significantly lower peak torque ratios at 5.23 rad · s?1 than judokas or soccer players, whereas males presented no ratio differences among sports At 5.23 rad · s?1. In the analysis by velocity, women's muscular ratios assessed at 1.05 rad · s?1 were significantly lower than at 5.23 rad · s?1 for all sports; among men, only judokas presented lower ratios at 1.05 rad · s?1 than at 5.23 rad · s?1. The present results suggest that sport modality and angular velocity influence the isokinetic strength profiles of men and women.     

3D preserving xviii century barroque masterpiece: Challenges and results on the digital preservation of Aleijadinho's sculpture of the Prophet Joel

We present our recent efforts in the digital preservation of a set of baroque sculptures made by Antônio Francisco Lisboa, known as O. Aleijadinho, which is an important American baroque artist. The set was made in the beginning of the xix century and is composed of 12 near real sized sculptures, hand-carved in soapstone. These sculptures represent 12 of the 16 prophets from the Holy Bible and are part of a UNESCO World Heritage Site. Our group has been collaborating with UNESCO in a project that aims to preserve all these statues. We hereby present our initial efforts, consisting of the 3D digital preservation of the Prophet Joel sculpture. We developed a complete 3D digital preservation pipeline composed of four main stages: data acquisition, 3D reconstruction, texture generation and 3D model visualization. By evaluating our results in this first sculpture, we discuss the improvements we conceived before applying our pipeline in the remaining ones. Finally, we present the 3D model of the Prophet which registers the sculpture's current state and will be used in restoration, research and educational activities. We believe this contribution may be useful to guide further research on similar scenarios, showing how to avoid some practical mistakes and achieve good results.     

From the Newspaper to the ‘News‐screen’ in Portuguese Schools

Abstracts

English: The paper points out the main objectives of school newspaper production, emphasizing those that may be achieved through work with electronic papers ‐ media competence and hypermedia literacy ‐ which are so important in the Information Society, and crucial for lifelong independent learning which is required in our continuously changing world. A pedagogical approach to the work with online papers which stresses the advantages of ‘learning by doing’ is suggested. A short overview of the Portuguese situation as to the integration of the new Information Technologies in schools will be followed by a presentation of some examples of electronic newspapers produced by Portuguese pupils.

The linear reading mechanisms of traditional papers are compared to those of online papers based on hypertext. The differences in the lay‐out and logic and in the ways of organizing information at the conceptual level will be mentioned, alongside some basic rules for writing an electronic newspaper.     

The Contribution of Ethnobiology to the Construction of a Dialogue Between Ways of Knowing: A Case Study in a Brazilian Public High School

This paper reports results obtained in pedagogical interventions in a Brazilian public high school which aimed at promoting a dialogue between scientific and traditional knowledge in the context of biology teaching. The interventions were based on the use of a didactic material and teaching sequence elaborated on the grounds of school knowledge about botany, as presented in biology textbooks, and interviews with students who were also farmers, so as to gather data about their ethnobiological knowledge. Our goal was to develop and test resources that can offer support for teachers who wish to build a dialogue between different ways of knowing in multicultural settings. Our results indicate that the use of the didactic material and teaching sequence indeed created possibilities for a dialogue between the students’ ethnobiological knowledge and biology school knowledge. We observed some shortcomings in classroom practice, partly reflecting our very choice of subject matter to develop the teaching sequence. But the interventions also revealed important limitations that we regard as representative of problems that may generally make multicultural science teaching a hard goal to achieve. It was clear that important shortcomings were related to teachers’ difficulties to conduct a dialogue between ways of knowing in a science classroom, and, thus, called attention to the importance of introducing a multicultural dimension into teacher education. We also observed that the fact that students did not show much sensitivity towards dealing with cultural diversity was a factor constraining the success of the interventions. These results highlight the importance of proposing and testing teacher education initiatives aiming at preparing them to teach science in a culturally sensitive manner, and also managing classroom tensions and conflicts so as to make it possible an effective dialogue between different ways of knowing in a multicultural setting.