Investigating short- and long-term transfer effects of a Taiji beginner course in participants’ daily life

OBJECTIVE: In recent years research investigating various health benefits of Taiji practice has markedly increased. Despite this growing scientific interest, essential questions such as to what extent a Taiji course may exert noticeable effects in participants’ everyday life, what these effects are, and how and where potential transfer effects occur, have hardly been considered. The aim of our study was to explore transfer effects from a Taiji course into participants’ daily lives. METHODS: We conducted a longitudinal observational study in 45 healthy participants at the end of their three-month Taiji beginner course (tp1) and at two months (tp2) as well as one year after course completion (tp3). Participants were asked to report their Taiji practice behavior at all time points, as well as to rate and describe perceived transfer effects of Taiji course contents on their daily life at tp1 and tp3. RESULTS: Transfer effects were reported by 91.1% of all respondents after course completion (tp1) and persisted in 73.3% at the one-year follow-up assessment (tp3), counting “increase of self-efficacy”, “improvement of stress management”, and “increase of body awareness” as the most frequently mentioned effects. Transfer effects predominantly occurred in participants’ work and social environments, as well as during everyday activities in public areas. While selfreliant Taiji practice frequency significantly decreased from 82.2% at tp1 to 55.6% at tp3 (P < 0.001), the magnitude of self-reported transfer effects did not (P = 0.35). As explorative analyses revealed, regular Taiji course attendance was highly correlated with stronger transfer effects at tp1 (r = 0.51; P < 0.001) and tp3 (r = 0.35; P = 0.020). Participants reporting high self-reliant Taiji practice frequency at tp2 were likely to maintain a regular practice routine at tp3 (r = 0.42; P < 0.004), whereas self-reliant practice frequency and transfer effects at tp1 were positively correlated with self-reliant practice frequency at tp3 on a trend level (r < 0.27; P > 0.08). CONCLUSION: Our data underline the importance of regular course participation for pronounced and long lasting transfer effects into participants’ everyday life. We discuss that several context and process-related aspects of a Taiji intervention are potentially relevant factors for enhancement of transfer effect.

Privacy-Preserving Optimal Meeting Location Determination on Mobile Devices

Equipped with state-of-the-art smartphones and mobile devices, today's highly interconnected urban population is increasingly dependent on these gadgets to organize and plan their daily lives. These applications often rely on current (or preferred) locations of individual users or a group of users to provide the desired service, which jeopardizes their privacy; users do not necessarily want to reveal their current (or preferred) locations to the service provider or to other, possibly untrusted, users. In this paper, we propose privacy-preserving algorithms for determining an optimal meeting location for a group of users. We perform a thorough privacy evaluation by formally quantifying privacy-loss of the proposed approaches. In order to study the performance of our algorithms in a real deployment, we implement and test their execution efficiency on Nokia smartphones. By means of a targeted user-study, we attempt to get an insight into the privacy-awareness of users in location-based services and the usability of the proposed solutions.

Executive functions after pediatric mild traumatic brain injury: A prospective short-term longitudinal study

Traumatic brain injuries (TBIs) occur frequently in childhood and entail broad cognitive deficits, particularly in the domain of executive functions (EF). Concerning mild TBI (mTBI), only little empirical evidence is available on acute and postacute performance in EF. Given that EF are linked to school adaptation and achievement, even subtle deficits in performance may affect children's academic careers. The present study assessed performance in the EF components of inhibition, working memory (WM), and switching in children after mTBI. Regarding both acute and postacute consequences, performance trajectories were measured in 13 patients aged between 5 and 10 years and 13 controls who were closely matched in terms of sex, age, and education. Performance in the EF components of inhibition, switching, and WM was assessed in a short-term longitudinal design at 2, 6, and 12 weeks after the mTBI. Results indicate subtle deficits after mTBI, which became apparent in the longitudinal trajectory in the EF components of switching and WM. Compared with controls, children who sustained mTBI displayed an inferior performance enhancement across testing sessions in the first 6 weeks after the injury in switching and WM, resulting in a delayed deficit in the EF component of WM 12 weeks after the injury. Results are interpreted as mTBI-related deficits that become evident in terms of an inability to profit from previous learning opportunities, a finding that is potentially important for children's mastery of their daily lives.

Livelihood and Community Development: LforS learning and simulation game

Up to 15 people can participate in the game, which is supervised by a moderator. Households consisting of 1-5 people discuss options for diversification of household strategies. Aim of the game: By devising appropriate strategies, households seek to stand up to various types of events while improving their economic and social situation and, at the same time, taking account of ecological conditions. The annual General Community Meeting (GCM) provides an opportunity for households to create a general set-up at the local level that is more or less favourable to the strategies they are pursuing. The development of a community investment strategy, to be implemented by the GCM, and successful coordination between households will allow players to optimise their investments at the household level. The household who owns the most assets at the end of the game wins. Players participate very actively, as the game stimulates lively and interesting discussions. They find themselves confronted with different types of decision-making related to the reality of their daily lives. They explore different ways to model their own household strategies and discuss risks and opportunities. Reflections on the course of the game continually refer to the real-life situations of the participants.

Energy Efficient Multimedia Communications in IEEE 802.11 Networks

During the last decade wireless mobile communications have progressively become part of the people’s daily lives, leading users to expect to be “alwaysbest-connected” to the Internet, regardless of their location or time of day. This is indeed motivated by the fact that wireless access networks are increasingly ubiquitous, through different types of service providers, together with an outburst of thoroughly portable devices, namely laptops, tablets, mobile phones, among others. The “anytime and anywhere” connectivity criterion raises new challenges regarding the devices’ battery lifetime management, as energy becomes the most noteworthy restriction of the end-users’ satisfaction. This wireless access context has also stimulated the development of novel multimedia applications with high network demands, although lacking in energy-aware design. Therefore, the relationship between energy consumption and the quality of the multimedia applications perceived by end-users should be carefully investigated. This dissertation addresses energy-efficient multimedia communications in the IEEE 802.11 standard, which is the most widely used wireless access technology. It advances the literature by proposing a unique empirical assessment methodology and new power-saving algorithms, always bearing in mind the end-users’ feedback and evaluating quality perception. The new EViTEQ framework proposed in this thesis, for measuring video transmission quality and energy consumption simultaneously, in an integrated way, reveals the importance of having an empirical and high-accuracy methodology to assess the trade-off between quality and energy consumption, raised by the new end-users’ requirements. Extensive evaluations conducted with the EViTEQ framework revealed its flexibility and capability to accurately report both video transmission quality and energy consumption, as well as to be employed in rigorous investigations of network interface energy consumption patterns, regardless of the wireless access technology. Following the need to enhance the trade-off between energy consumption and application quality, this thesis proposes the Optimized Power save Algorithm for continuous Media Applications (OPAMA). By using the end-users’ feedback to establish a proper trade-off between energy consumption and application performance, OPAMA aims at enhancing the energy efficiency of end-users’ devices accessing the network through IEEE 802.11. OPAMA performance has been thoroughly analyzed within different scenarios and application types, including a simulation study and a real deployment in an Android testbed. When compared with the most popular standard power-saving mechanisms defined in the IEEE 802.11 standard, the obtained results revealed OPAMA’s capability to enhance energy efficiency, while keeping end-users’ Quality of Experience within the defined bounds. Furthermore, OPAMA was optimized to enable superior energy savings in multiple station environments, resulting in a new proposal called Enhanced Power Saving Mechanism for Multiple station Environments (OPAMA-EPS4ME). The results of this thesis highlight the relevance of having a highly accurate methodology to assess energy consumption and application quality when aiming to optimize the trade-off between energy and quality. Additionally, the obtained results based both on simulation and testbed evaluations, show clear benefits from employing userdriven power-saving techniques, such as OPAMA, instead of IEEE 802.11 standard power-saving approaches.