The metabolic and temporal basis of muscle hypertrophy in response to resistance exercise

Constituting ～40% of body mass, skeletal muscle has essential locomotory and metabolic functions. As such, an insight into the control of muscle mass is of great importance for maintaining health and quality-of-life into older age, under conditions of cachectic disease and with rehabilitation. In healthy weight-bearing individuals, muscle mass is maintained by the equilibrium between muscle protein synthesis (MPS) and muscle protein breakdown; when this balance tips in favour of MPS hypertrophy occurs. Despite considerable research into pharmacological/nutraceutical interventions, resistance exercise training (RE-T) remains the most potent stimulator of MPS and hypertrophy (in the majority of individuals). However, the mechanism(s) and time course of hypertrophic responses to RE-T remain poorly understood. We would suggest that available data are very much in favour of the notion that the majority of hypertrophy occurs in the early phases of RE-T (though still controversial to some) and that, for the most part, continued gains are hard to come by. Whilst the mechanisms of muscle hypertrophy represent the culmination of mechanical, auto/paracrine and endocrine events, the measurement of MPS remains a cornerstone for understanding the control of hypertrophy – mainly because it is the underlying driving force behind skeletal muscle hypertrophy. Development of sophisticated isotopic techniques (i.e. deuterium oxide) that lend to longer term insight into the control of hypertrophy by sustained RE-T will be paramount in providing insights into the metabolic and temporal regulation of hypertrophy. Such technologies will have broad application in muscle mass intervention for both athletes and for mitigating disease/age-related cachexia and sarcopenia, alike.     

‘It just makes you feel invincible’: a Foucauldian analysis of children's experiences of organised team sports

The childhood years are highlighted as a crucial time when ongoing participation in physical activity can be nurtured and maintained. The nurturing of a child's proclivity to participate in organised sport normally falls into the domain of adults. While both parents and coaches have been identified as key influences on children's enjoyment of sport, some negative perceptions exist about their roles. Although children's perspectives are increasingly being acknowledged as valuable, it would appear that young children are still marginalised as active participants in areas of health-related research. The primary objective of this study was to give space to children's views of organised sport and to examine how adult behaviours affected these children's enjoyment of sport. This qualitative study utilised eight focus group interviews with a total of 30 children (aged 6–11 years) in the Greater Auckland area of New Zealand. This paper presents a Foucauldian discourse analysis of children's views relating to their sporting experiences. Children articulated three discursive constructions of sport: sport as competition, sport as fun and sport as fair play. The dominance of sport as competition would appear to serve the needs of coaches and parents more than those of children. Coaches who appear to be firmly positioned within a competitive discourse of sport use their power to support coaching practices that clash with the guidelines provided for them by their sporting bodies. Our analysis shows that many children may be exposed to discursive practices that are not conducive to a child-centred sporting environment. Through the exercise of disciplinary measures, there is pressure on children to conform to the normative behaviours associated with a dominant competitive sport discourse.     

Quantification of brake data acquired with a brake power meter during simulated cross-country mountain bike racing

There is currently a dearth of information describing cycling performance outside of propulsive and physiological variables. The aim of the present study was to utilise a brake power meter to quantify braking during a multi-lap cross-country mountain bike time trial and to determine how braking affects performance. A significant negative association was determined between lap time and brake power (800.8 ± 216.4 W, mean ± SD; r = ?0.446; p < 0.05), while the time spent braking (28.0 ± 6.4 s) was positively associated with lap time (314.3 ± 37.9 s; r = 0.477; p < 0.05). Despite propulsive power decreasing after the first lap (p < 0.05), lap time remained unchanged (p > 0.05) which was attributed to decreased brake work (p < 0.05) and brake time (p < 0.05) in both the front and rear brakes by the final lap. A multiple regression model incorporating braking and propulsion was able to explain more of the variance in lap time (r² = 0.935) than propulsion alone (r² = 0.826). The present study highlights that riders’ braking contributes to mountain bike performance. As riders repeat a cross-country mountain bike track, they are able to change braking, which in turn can counterbalance a reduction in power output. Further research is required to understand braking better.     

Are contextual and designed student–student interaction treatments equally effective in distance education?

This systematic review draws from and builds upon the results of a meta-analysis of the achievement effects of three types of interaction treatments in distance education: student–student, student–teacher, and student–content (Bernard et al., Review of Educational Research, 79(3), 1243–1289, 2009). This follow-up study considers two forms of student–student interaction treatments, contextual interaction and designed interaction. Typical contextual interaction treatments contain the necessary conditions for student–student interaction to occur, but are not intentionally designed to create collaborative learning environments. By contrast, designed interaction treatments are intentionally implemented collaborative instructional conditions for increasing student learning. Our meta-analysis compared the effect of these two types of interaction treatments on student achievement outcomes. The results favored designed interaction treatments over contextual interaction treatments. Examples of designed interaction treatments and a discussion of study results and their potential implications for research and instruction in distance education and online learning are presented.     

Implementing technical refinement in high-level athletics: exploring the knowledge schemas of coaches

This paper explores the approaches adopted by high-level field athletics coaches when attempting to refine an athlete’s already well-established technique (long and triple jump and javelin throwing). Six coaches, who had all coached multiple athletes to multiple major championships, took part in semi-structured interviews focused upon a recent example of technique refinement. Data were analysed using a thematic content analysis. The coaching tools reported were generally consistent with those advised by the existing literature, focusing on attaining “buy-in”, utilising part-practice, restoring movement automaticity and securing performance under pressure. Five of the six coaches reported using a systematic sequence of stages to implement the refinement, although the number and content of these stages varied between them. Notably, however, there were no formal sources of knowledge (e.g., coach education or training) provided to inform coaches’ decision making. Instead, coaches’ decisions were largely based on experience both within and outside the sporting domain. Data offer a useful stimulus for reflection amongst sport practitioners confronted by the problem of technique refinement. Certainly the limited awareness of existing guidelines on technique refinement expressed by the coaches emphasises a need for further collaborative work by researchers and coach educators to disseminate best practice.     

Validity of a device designed to measure braking power in bicycle disc brakes

Real-world cycling performance depends not only on exercise capacities, but also on efficiently traversing the bicycle through the terrain. The aim of this study was to determine if it was possible to quantify the braking done by a cyclist in the field. One cyclist performed 408 braking trials (348 on a flat road; 60 on a flat dirt path) over 5 days on a bicycle fitted with brake torque and angular velocity sensors to measure brake power. Based on Newtonian physics, the sum of brake work, aerodynamic drag and rolling resistance was compared with the change in kinetic energy in each braking event. Strong linear relationships between the total energy removed from the bicycle-rider system through braking and the change in kinetic energy were observed on the tar-sealed road (r² = 0.989; p < 0.0001) and the dirt path (r² = 0.952; p < 0.0001). T-tests revealed no difference between the total energy removed and the change in kinetic energy on the road (p = 0.715) or dirt (p = 0.128). This study highlights that brake torque and angular velocity sensors are valid for calculating brake power on the disc brakes of a bicycle in field conditions. Such a device may be useful for investigating cyclists’ ability to traverse through various terrains.     

Towards an ethical ecology of international service learning

International Service-Learning (ISL) is a pedagogical activity that seeks to blend student learning with community engagement overseas and the development of a more just society. ISL programmes have grown as educational institutions and non-governmental organizations have sought to achieve the goal of developing ‘global citizens’. However, Service Learning (SL) in general and International Service-Learning (ISL) in particular remain deeply under-theorized. These educational initiatives provide policy-makers with a practical response to their quest for a ‘Big Society’ and present alluring pedagogical approaches for Universities as they react to reforms in Higher Education and seek to enhance both the student learning experience and graduate employability. After outlining the development of ISL in policy and practice, this paper draws on the rich tradition of ISL at one British university to argue that ISL is a form of engagement that has the potential to be ethical in character, although a number of factors are identified that militate against this. The contention is that ISL which promotes rational and instrumental learning represents a deficit model and, therefore, ISL is conceptualized here as a transformative learning experience that evinces distinctly aesthetic and even spiritual dimensions. Upon this theoretical groundwork is laid the foundations for conceptualizing ISL in ways that ensure its ethical integrity.     

An empirical basis for route choice in cycling

We used data from international cycle stage races to examine a rule for cyclists that is similar to Naismith's rule. Naismith's rule is used by walkers to estimate travel times for routes involving climb (i.e. the vertical distance component of a route). The rule is also used in route choice decision-making to compare differing, competing routes. We developed such a rule for use in cycling events, and also considered an extension of the climb-distance rule to take account of the effect of type of terrain or rideability. A simple analysis of the data suggests that 1 m of vertical travel on a bicycle can be considered to be equivalent to approximately 8 m of horizontal travel. Thus the equivalent distance of a route may be calculated by taking its horizontal distance component and adding eight times its vertical distance component. The result obtained was shown to be in accord with mathematical models that relate cycling power to speed and gradient. An index that considers the effect of terrain is also reported, and incorporated into an equivalent distance model. Tentative values for the terrain or rideability index are suggested, and we argue that a distance of 1 km over good off-road terrain is equivalent to a distance of 2 km on-road, and that a distance of 1 km over poor off-road terrain is equivalent to a distance of 4 km on-road.     

Culture Shock and Higher Education Performance: Implications for Teaching

The globalisation of higher education brings together learners and teachers from differing systems, creating a heterogeneous and diverse environment. Yet many higher education institutions typically rely on foreign students themselves to adapt to their new higher education environments. An investigation was undertaken as to whether traditional approaches are effective and efficient in meeting the needs of the internationally mobile student. Using data from the last ten years (1999 to 2009) from a post‐1992 University in the North West of England an analysis of over 15,000 postgraduate assessments found a significant performance difference between home country students and international mobile students. Results found that home country students perform significantly better than international students, although the latter perform better in examinations than in coursework. However, there is a substantive improvement during the dissertation stage for both groups. Possible reasons for such variations in performance are explored.     

在并行文件系统中使用服务器到服务器的通讯来简化一致性检查并提高性能

并行计算将发展为使用上千个集群化的CPU完成一个应用程序,这导致I／O瓶颈随着集群中CPU密度的加大而日益严峻。目前的并行文件系统提供了大量的聚合I／O带宽,然而它们的可扩展性达不到管理上千个存储节点上的分布式文件的需求。这篇论文我们通过存储服务器之间的聚合通讯来提高文件大数据集操作的可扩展性。特别的,我们采用服务器到服务器的通讯方式来简化一致性检查,同时改善文件创建、删除和状态查询的性能。