Short-term and long-term site-specific effects of tennis playing on trabecular and cortical bone at the distal radius

Mechanical loading during growth magnifies the normal increase in bone diameter occurring in long bone shafts, but the response to loading in long bone ends remains unclear. The aim of the study was to investigate the effects of tennis playing during growth at the distal radius, comparing the bone response at trabecular and cortical skeletal sites. The influence of training duration was examined by studying bone response in short-term (children) and long-term (young adults) perspectives. Bone area, bone mineral content (BMC), and bone mineral density (BMD) of the radius were measured by DXA in 28 young (11.6 ± 1.4 years old) and 47 adult tennis players (22.3 ± 2.7 years old), and 70 age-matched controls (12 children, 58 adults) at three sites: the ultradistal region (trabecular), the mid-distal region, and the third-distal region (cortical). At the ultradistal radius, young and adult tennis players displayed similar side-to-side differences, the asymmetry in BMC reaching 16.3% and 13.8%, respectively (P < 0.0001). At the mid- and third-distal radius, the asymmetry was much greater in adults than in children (P < 0.0001) for all the bone parameters (mid-distal radius, +6.6% versus +15.6%; third-distal radius, +6.9% versus +13.3%, for BMC). Epiphyseal bone enduring longitudinal growth showed a great capacity to respond to mechanical loading in children. Prolonging tennis playing into adulthood was associated with further increase in bone mineralization at diaphyseal skeletal sites. These findings illustrate the benefits of practicing impact-loading sports during growth and maintaining physical activity into adulthood to enhance bone mass accrual and prevent fractures later in life.

Comparison of pQCT parameters between ulna and radius in retired elite gymnasts : the skeletal benefits associated with long-term gymnastics are bone- and site-specific

Objectives: To compare the skeletal benefits associated with gymnastics between ulna and radius.
Methods: 19 retired artistic gymnasts, aged 18-36 years, were compared to 24 sedentary women. Bone mineral content (BMC), total and cortical bone area (ToA, CoA), trabecular and cortical volumetric density (TrD, CoD) and cortical thickness (CoTh) were measured by pQCT at the 4% and 66% forearm.
Results: At the 4% site, BMC and ToA were more than twice greater at the radius than ulna whereas at the 66% site, BMC, ToA, CoA, CoTh and SSIpol were 20 to 51% greater at the ulna than radius in both groups (p<0.0001). At the 4% site, the skeletal benefits in BMC of the retired gymnasts over the non-gymnasts were 1.9 times greater at the radius than ulna (p<0.001), with enlarged bone size at the distal radius only. In contrast, the skeletal benefits at the 66% site were twice greater at the ulna than radius for BMC and CoA (p<0.01).
Conclusion: Whereas the skeletal benefits associated with long-term gymnastics were greater at the radius than ulna in the distal forearm, the reverse was found in the proximal forearm, suggesting both bones should be analysed when investigating forearm strength.

Polyalanine repeat polymorphism in RUNX2 is associated with site-specific fracture in post-menopausal femals

Runt related transcription factor 2 (RUNX2) is a key regulator of osteoblast differentiation. Several variations within the RUNX2 gene have been found to be associated with significant changes in BMD, which is a major risk factor for fracture. In this study we report that an 18 bp deletion within the polyalanine tract (17A>11A) of RUNX2 is significantly associated with fracture. Carriers of the 11A allele were found to be nearly twice as likely to have sustained fracture. Within the fracture category, there was a significant tendency of 11A carriers to present with fractures of distal radius and bones of intramembranous origin compared to bones of endochondral origin (p = 0.0001). In a population of random subjects, the 11A allele was associated with decreased levels of serum collagen cross links (CTx, p = 0.01), suggesting decreased bone turnover. The transactivation function of the 11A allele showed a minor quantitative decrease. Interestingly, we found no effect of the 11A allele on BMD at multiple skeletal sites. These findings suggest that the 11A allele is a biologically relevant polymorphism that influences serum CTx and confers enhanced fracture risk in a site-selective manner related to intramembranous bone ossification.

Constitutionalism, good faith and the doctrine of specific performance: rights, duties and equitable discretion

This article will explore the European roots of the doctrine of specific performance and the influence of transformative constitutionalism on these in recent times. The question whether specific performance is available as of right (as in the civil law), or only subject to judicial discretion (as in the common law), will be investigated. The demonstrated impact of constitutional rights on contract law in the mixed system of South Africa will be contrasted with developments in English and Australian contract law, where the common-law rules are more deeply entrenched and the potential scope for human rights-based development of these is arguably smaller, though still important. The article will argue, using comparative rules on specific performance as an example, that the concept of a duty of good faith or contractual fairness is likely to play a greater role in future in all three of the countries under consideration, reducing the common/civil/mixed legal systems divide.

Structural health monitoring: a practical approach to achieving in-situ and site-specific warning of pipeline corrosion and coating failure

An approach to achieving the ambitious goal of cost effectively extending the safe operation life of energy pipelines to, for instance, 100 years is the application of structural health monitoring and life prediction tools that are able to provide long-term remnant pipeline life prediction and in-situ pipeline condition monitoring. A critical step in pipeline structural health monitoring is the enhancement of technological capabilities that are required for quantifying the effects of key factors influencing buried pipeline corrosion and environmentally assisted materials degradation, and the development of condition monitoring technologies that are able to provide in-situ monitoring and site-specific warning of pipeline damage. This paper provides an overview of our current research aimed at developing new sensors for monitoring, categorising and quantifying the level and nature of external pipeline and coating damages under the combined effects of various inter-related variables and processes such as localised corrosion, coating damage and disbondment, cathodic shielding. The concept of in-situ monitoring and site-specific warning of pipeline corrosion is illustrated by a case of monitoring localised corrosion under disbonded coatings using a new corrosion monitoring probe. A basic principle that underpins the use of sensors to monitor localised corrosion has been presented: Localised corrosion and coating failure are not an accidental occurrence, it occurs as the result of fundamental thermodynamic instability of a metal exposed to a specific environment. Therefore corrosion and coating disbondment occurring on a pipeline will also occur on a sensor made of the same material and exposed to the same pipeline condition. Although the exact location of localised corrosion or coating disbondment could be difficult to pinpoint along the length of a buried pipeline, the ‘worst-case scenario’ and high risk pipeline sections and sites are predictable. Sensors can be embedded at these strategic sites to collect data that contain ‘predictor features’ signifying the occurrence of localised corrosion, CP failure, coating disbondment and degradation. Information from these sensors will enable pipeline owners to prioritise site survey and inspection operations, and to develop maintenance strategy to manage aged pipelines, rather than replace them.

Retrieval

Retrieval was a site-specific performance installation which transformed five floors of the National Library of Australia in Nov-Dec 2010. Devised in collaboration with a team of 30 young performers, the production lead the audience on a quest deep into the library to retrieve priceless cultural memories before all was lost. Louise Morris working in collaboration with co-designer Matthew Aberline and the artistic team created the installed environments for the production. The production won numerous awards including Best New Project- Express Media and Best Original Work- CAT awards.

Flickering

Three dancers moved between and into Lake Bolac’s historic and community buildings dancing in each building. A series of transient micro-dances intimately inhabited the spaces themselves, stirred by the qualities and impact of the architecture. Evoking ghosts of the past but also inviting fresh eyes for these spaces, the mingling of past and present was embodied in the presence of the performers as they traversed the township of Lake Bolac.

Chime

A multi-disciplinary, site-specific performance which moved between several spaces in the Courthouse Arts building. The work combined improvised dance, choreographic practice, video projection and sound which utilized and computer-manipulated the Federation Handbells.

Stories from the river

Stories from the River was a visual investigation into the forgotten history of the Yarra River presented by students studying Performance for Alternative Spaces at Deakin University’s School of Communication and Creative Arts. They dredged from the river, forgotten objects…and every object had a story to tell. On the main lawns of Arts Centre Melbourne, the objects were placed as symbols of remembrance to the mysterious and intriguing history of the River.

Anthology

This research is a practice led investigation of large-scale site specific performance installation works that respond to local and historical trauma, place making, and belonging for communities and audiences. The research is part of an ongoing PhD which is primarily questioning how layers of history and lived experience manifest or ‘imprint’ upon natural landscapes and urban sites using the driving concepts of landscape, archaeology, and community immersion to inform the practice. The site of the primary research investigation was Anthology www.anthology.net.au- a major site-specific theatrical journey through Westlake, now known as Stirling Park – Ngunawal land, a traditional pathway and the site of one of the camps created to house the workers building the new city of Canberra. Tents and a hall were erected followed by 61 cottages built in 1923, for married tradesmen building the infrastructure for the new Federal Capital of Australia. These families lived at Westlake for 50 years until the 1960’s when the families were relocated, the houses sold and removed. A community demolished. Westlake is now parkland (and prime real estate), nestled between the lake and the Embassies of Yarralumla. The event took place between 26th November and the 6th December 2014. The performance installation was created and produced over a 3-year period with $45,000.00 in funding provided by ArtsACT and the Centenary of Canberra. Anthology alluded to the power of immersive, site-sympathetic performance as a regenerative force for communities right now. What lies in wait for artists in sites, in places…to be uncovered…with its final form revealed through careful excavation? Anthology centralised rituals of remembrance and the importance of place as vital to the restoration and regeneration of community through processing and transcending what has been lost, hidden, suppressed or in the case of Westlake or Stirling Park ‘vanished’.

Now again

Now Again is a participatory performance made up of a series of individual and group activities that create opportunities to notice how we fit and shift in our environment. Reflecting the dance histories of the artists, the variable dynamic possibilities of the city are brought into focus through specific ‘scores’ that, as propositions for engagement, activate simple movement patterns or observations. The aim is to allow responsive noticing of the immediate environment, but also to enliven it in unexpected ways. Individuals who are participants and observers, dedicated or incidental (passers-by), become part of the disclosure of the physical and the social. The rigid structure of the city is re-imagined as a fluid, choreographic entity invested with organic qualities. Performances move between a series of city locations, each with differing activities. Designated ‘nodes’ in the city grid (certain streets, a square, a doorway, footpath, a hole in a wall or a particular tree), have been chosen for their imaginative, affective, or energetic resonances. These are ‘mapped’ by the perambulatory, physical, sensory, and relational engagement of all participants. This is a collective dance created through noticing the feelings and patterns of the physical self in the built, natural, and social environment. In some sites, the artists perform, while in others they lead a participative performance. Ephemeral, self-led, performance experiments designed to disappear into the fabric of the city, will also be invited. A mobile app enables audience participation. The app employs GPS data to trigger information specific to that site (written prompts, sounds and scored provocations).