Foot and ankle joint movements of dancers and non-dancers: a comparative study

Ballerinas use their ankle joints more extremely and sustain injuries on the ankle joint more frequently than non-dancers. Therefore, the ankle movement of dancers is important and should be studied to prevent injuries. Measuring ankle joint range of motion (ROM) using radiographs could demonstrate the contribution to motion of each joint. The aim of this study was to analyse and compare ankle joint movements and the ratio of each joint’s contribution during movement between dancers and non-dancers, using radiographic images. Dancers have lower dorsiflexion (26.7 ± 6.2°), higher plantarflexion (74.3 ± 7.1°) and higher total (101.1 ± 10.8°) ROMs than non-dancers (33.9 ± 7.0°, 57.2 ± 6.8° and 91.1 ± 9.3°, respectively) (p < 0.05). Although the ROMs were different between the two groups, the ratios of each joint movement were similar between these two groups, in all movements. Regarding total movement, the movement ratio of the talocrural joint was almost 70% and other joints accounted for almost 30% of the movement role in both dancers and non-dancers. Therefore, the differences in ROM between dancers and non-dancers were not a result of a specific joint movement but of all the relevant joints’ collaborative movement.     

The importance of indirect teaching behaviour and its educational effects in physical education

Background: Physical education teacher behaviour has been a subject of study in physical education including physical education teacher education for 30 years. However, the research on teacher behaviour has tended to focus on direct teaching behaviour (DTB) to demonstrate the benefits of effective teaching, centred on a technical understanding of the process of teacher behaviour. A holistic approach for teaching behaviour is needed in order to give students educational experiences.

Aims: Drawing on the studies of implicit ways of teaching, the aim of this paper is to provide a new approach of researching teacher behaviour in order to understand the social and moral assumptions and to promote students' motivation to engage in physical activities that are embedded in the act of teaching in physical education through the identification of indirect teaching behaviour (ITB).

Method: An ethnographically informed case study based on participant observation (eight months) was employed. The researcher observed students in two 8th-grade (13 years old) co-ed physical education classes in South Korea. Participant observation was supported by participant observer field notes, audio/video recordings of classes, questionnaires, and interviews.

Findings: Through inductive analysis of the data, the multiple ITBs were identified including tone of voice and intonation, humour, facial expressions and gestures, dress code and setting an example, touch, encouragement, and care. ITB had a powerful influence on students' social and moral development in terms of reflecting on themselves by the teacher's positive modelling, cooperating with other friends and learning the intrinsic value of physical activities and sports. ITB was also found to impact the student's perceptions of physical education and their physical education teachers, which seems to encourage them to learn more about the lesson.

Conclusions: An understanding of ITB will help broaden the perspectives on teaching methods used and studies conducted in physical education beyond the dominant approach of DTBs. Teachers need to reflect upon their behaviour in the physical education class, even if their teaching behaviours are regarded as trivial. Furthermore, the understanding of ITB can also play a pivotal role in encouraging pupils to enjoy the intrinsic value of physical education centred on moral values, and fostering a passion for physical activity that extends into participation for life. In this sense, this insight suggests that researchers re-examine the power of ITB in relation to teachers' professional competence. Teacher educators need to intentionally cultivate the character of teacher candidates in their professional preparation phase in addition to ITB-related studies in physical education.     

Decolonizing educational/curriculum studies in East Asia: problematizing shadow education in South Korea

This essay review critically engages Young Chun Kim's book, Shadow Education and the Curriculum and Culture of Schooling in South Korea, by responding to two central questions at its heart: What does decolonization of educational research mean and what does it look like? In what way can cultural studies of countries with histories of colonized educational systems challenge the inertia to recapitulate colonized historical consciousness? Kim provides theoretical and empirical foundations for generating intellectual space that reveals the dialectical relationship between the dominant modes of discourse in educational research and aspirations of the colonized to envision their own educational culture and history.     

Does exercise have a protective effect on cognitive function under hypoxia? A systematic review with meta-analysis

ObjectiveThis study aimed to examine (1) the independent effects of hypoxia on cognitive function and (2) the effects of exercise on cognition while under hypoxia.MethodsDesign: Systematic review with meta-analysis. Data sources: PubMed, Scopus, Web of Science, PsychInfo, and SPORTDiscus were searched. Eligibility criteria for selecting studies: randomized controlled trials and nonrandomized controlled studies that investigated the effects of chronic or acute exercise on cognition under hypoxia were considered (Aim 2), as were studies investigating the effects of hypoxia on cognition (Aim 1).ResultsIn total, 18 studies met our inclusionary criteria for the systematic review, and 12 studies were meta-analyzed. Exposure to hypoxia impaired attentional ability (standardized mean difference (SMD) = –0.4), executive function (SMD = –0.18), and memory function (SMD = –0.26), but not information processing (SMD = 0.27). Aggregated results indicated that performing exercise under a hypoxia setting had a significant effect on cognitive improvement (SMD = 0.3, 95% confidence interval: 0.14 – 0.45, I² = 54%, p < 0.001). Various characteristics (e.g., age, cognitive task type, exercise type, exercise intensity, training type, and hypoxia level) moderated the effects of hypoxia and exercise on cognitive function.ConclusionExercise during exposure to hypoxia improves cognitive function. This association appears to be moderated by individual and exercise/hypoxia-related characteristics.     

A group recommendation system for online communities

Online communities are virtual spaces over the Internet in which a group of people with similar interests or purposes interact with others and share information. To support group activities in online communities, a group recommendation procedure is needed. Though there have been attempts to establish group recommendation, they focus on off-line environments. Further, aggregating individuals’ preferences into a group preference or merging individual recommendations into group recommendations—an essential component of group recommendation—often results in dissatisfaction of a small number of group members while satisfying the majority. To support group activities in online communities, this paper proposes an improved group recommendation procedure that improves not only the group recommendation effectiveness but also the satisfaction of individual group members. It consists of two phases. The first phase was to generate a recommendation set for a group using the typical collaborative filtering method that most existing group recommendation systems utilize. The second phase was to remove irrelevant items from the recommendation set in order to improve satisfaction of individual members’ preferences. We built a prototype system and performed experiments. Our experiment results showed that the proposed system has consistently higher precision and individual members are more satisfied.     

Ontological framework based on contextual mediation for collaborative information retrieval

On the heterogeneous web information spaces, users have been suffering from efficiently searching for relevant information. This paper proposes a mediator agent system to estimate the semantics of unknown web spaces by learning the fragments gathered during the users' focused crawling. This process is organized as the following three tasks; (i) gathering semantic information about web spaces from personal agents while focused crawling in unknown spaces, (ii) reorganizing the information by using ontology alignment algorithm, and (iii) providing relevant semantic information to personal agents right before focused crawling. It makes the personal agent possible to recognize the corresponding user's behaviors in semantically heterogeneous spaces and predict his searching contexts. For the experiments, we implemented comparison-shopping system with heterogeneous web spaces. As a result, our proposed method efficiently supported the users, and then, network traffic was also reduced. An erratum to this article can be found at     

The Relationship Between Activities of Daily Living (ADL), Chronic Diseases,and Depression Among Older Korean Immigrants

It has been identified that performance of Activities of Daily living (ADL) and chronic disease are predictors of depression for older Asian immigrants. This study examined the independent and interactive effects of ADL performance and chronic disease on depressive symptoms among older Korean immigrants. Data from 210 older Korean immigrants in Los Angeles County were analyzed. Self-reported measures included sociodemographic characteristics, ADL performance, chronic disease, and depressive symptoms. A hierarchical regression model indicated that performance of activities of daily living were negatively associated with depressive symptoms. Also, older Korean immigrants with more chronic diseases were more likely to have depressive symptoms. The interaction between ADL performance and chronic diseases was significantly associated with lower levels of depressive symptoms (β = .46, p < .05). Findings suggest that it is critical to develop various strategies for enhancing immigrants’ ability to perform activities of daily living; this can lead to increased independence and reduced chronic illnesses, thus, improving overall quality of life.     

A sequence-based filtering method for exhibition booth visit recommendations

As exhibitions are known to play important roles in marketing and sales promotion, the exhibition industry has grown significantly not only in the exhibition event size and frequency but also in the number of participating firms and visitors. While the challenge in assessing economic returns from exhibitions is being studied, it is agreed that the eventual success of an exhibition resides largely in its ability to meet the visitors’ needs. Visitors use an exhibition as a source of information when searching for products or services. Though an exhibition provides an information-rich environment, however, visitors often get lost in the abundance of information. A specialized recommender system can be a good solution to information overload as it can guide visitors to right exhibition booths and help them collect necessary information. Traditional collaborative-filtering recommender systems, however, use only customers’ rating or purchase records so that they do not capture exhibition visitors’ temporal visit sequences and dynamic preferences. Moreover, due to the computation overhead, they cannot generate real-time recommendation in ubiquitous environments for exhibitions. In order to overcome these drawbacks, this study proposes a booth recommendation procedure that takes into consideration not only booth visit records but also visit sequences. Experiment results show that the proposed procedure achieves higher recommendation accuracy, faster computation, and more diversity than a typical collaborative-filtering recommender system. From the results, we conclude that the proposed booth recommendation procedure is suitable for real-time recommendation in ubiquitous exhibition environments.