The ultra-low friction of the articular surface is pH-dependent and is built on a hydrophobic underlay including a hypothesis on joint lubrication mechanism

In this study, the influence of pH on interfacial energy distributed over the phospholipids-bilayer surface model and the effect of hydrophobicity on coefficient of friction (f) were investigated by using microelectrophoresis. An important clinical implication of deficiency in hydrophobicity is the loss of phospholipids that is readily observed in osteoarthritis joints. This paper establishes the influence of pH on interfacial energy upon an increase f, which might be associated with a decrease of hydrophobicity of the articular surface.

Characterising the homeostatic and hedonic markers of the susceptible phenotype

Over the years, approaches to obesity prevention and treatment have gone from focusing on genetic and other biological factors to exploring a diversity of diets and individual behavior modification interventions anchored primarily in the power of the mind, to the recent shift focusing on societal interventions to design ";temptation-proof"; physical, social, and economic environments. In spite of repeated calls to action, including those of the World Health Organization (WHO), the pandemic continues to progress. WHO recently projected that if the current lifestyle trend in young and adult populations around the world persist, by 2012 in countries like the USA, health care costs may amount to as much as 17.7% of the GDP. Most importantly, in large part due to the problems of obesity, those children may be the first generation ever to have a shorter life expectancy than that of their parents. This work presents the most current research and proposals for addressing the pandemic. Past studies have focused primarly on either genetic or behavioral causes for obesity, however today's research indicates that a strongly integrated program is the best prospect for success in overcoming obesity. Furthermore, focus on the role of society in establishing an affordable, accessible and sustainable program for implementing these lifestyle changes is vital, particularly for those in economically challenged situations, who are ultimately at the highest risk for obesity. Using studies from both neuroscience and behavioral science to present a comprehensive overview of the challenges and possible solutions, The brain-to-society approach to obesity prevention focuses on what is needed in order to sustain a healthy, pleasurable and affordable lifestyle.

Development of a multi-scale finite element model of the osteoporotic lumbar vertebral body for the investigation of apparent level vertebra mechanics and micro-level trabecular mechanics.

Osteoporotic spinal fractures are a major concern in ageing Western societies. This study develops a multi-scale finite element (FE) model of the osteoporotic lumbar vertebral body to study the mechanics of vertebral compression fracture at both the apparent (whole vertebral body) and micro-structural (internal trabecular bone core)levels. Model predictions were verified against experimental data, and found to provide a reasonably good representation of the mechanics of the osteoporotic vertebral body. This novel modelling methodology will allow detailed investigation of how trabecular bone loss in osteoporosis affects vertebral stiffness and strength in the lumbar spine.

The effect of friction on indenter force and pile-up in numerical simulations of bone nanoindentation

Nanoindentation is a useful technique for probing the mechanical properties of bone, and finite element (FE) modeling of the indentation allows inverse determination of elasto-plastic constitutive properties. However, FE simulations to date have assumed frictionless contact between indenter and bone. The aim of this study was to explore the effect of friction in simulations of bone nanoindentation. Two dimensional axisymmetric FE simulations were performed using a spheroconical indenter of tip radius 0.6m and angle 90°. The coefficient of friction between indenter and bone was varied between 0.0 (frictionless) and 0.3. Isotropic linear elasticity was used in all simulations, with bone elastic modulus E=13.56GPa and Poisson’s ratio =0.3. Plasticity was incorporated using both Drucker-Prager and von Mises yield surfaces. Friction had a modest effect on the predicted force-indentation curve for both von Mises and Drucker-Prager plasticity, reducing maximum indenter displacement by 10% and 20% respectively as friction coefficient was increased from zero to 0.3 (at a maximum indenter force of 5mN). However, friction has a much greater effect on predicted pile-up after indentation, reducing predicted pile-up from 0.27m to 0.11m with a von Mises model, and from 0.09m to 0.02m with Drucker-Prager plasticity. We conclude that it is important to include friction in nanoindentation simulations of bone.

Design and evaluation of an MRI compatible axial compression device for 3D assessment of spinal deformity and flexibility in adolescent idiopathic scoliosis

Magnetic Resonance Imaging (MRI) offers a valuable research tool for the assessment of 3D spinal deformity in AIS, however the horizontal patient position imposed by conventional scanners removes the axial compressive loading on the spine. The objective of this study was to design, construct and test an MRI compatible compression device for research into the effect of axial loading on spinal deformity using supine MRI scans. The device was evaluated by performing unloaded and loaded supine MRI scans on a series of 10 AIS patients. The patient group had a mean initial (unloaded) major Cobb angle of 43±7º, which increased to 50±9º on application of the compressive load. The 7° increase in mean Cobb angle is consistent with that reported by a previous study comparing standing versus supine posture in scoliosis patients (Torell et al, 1985. Spine 10:425-7).

Distribution of forces during fulcrum bending radiographs on adolescent idiopathic scoliosis patients

At the Mater Children’s Hospital, approximately 80% of patients presenting with Adolescent Idiopathic Scoliosis requiring corrective surgery receive a fulcrum bending radiograph. The fulcrum bending radiograph provides a measurement of spine flexibility and a better indication of achievable surgical correction than lateral-bending radiographs (Cheung and Luk, 1997; Hay et al 2008). The magnitude and distribution of the corrective force exerted by the bolster on the patient’s body is unknown. The objective of this pilot study was to measure, for the first time, the forces transmitted to the patient’s ribs through the bolster during the fulcrum bending radiograph.

Development of patient-specific computer simulation tools for endoscopic scoliosis surgery

Endoscopic approaches for anterior correction of idiopathic scoliosis are a relatively new surgical technique. This paper describes the development of patient-specific finite element modelling techniques to investigate the biomechanics of single rod anterior scoliosis correction. Spinal geometry is obtained from pre-operative CT scans and material properties for osteo-ligamentous spinal tissues are based on existing literature. The techniques being developed will allow pre-surgical prediction of stresses, forces and deformations in spinal tissues, rods and screws under post-operative physiological loads.

An improved modal strain energy method for damage assessment

The modal strain energy method, which depends on the vibration characteristics of the structure, has been reasonably successful in identifying and localising damage in the structure. However, existing strain energy methods require the first few modes to be measured to provide meaningful damage detection. Use of individual modes with existing strain energy methods may indicate false alarms or may not detect the damage at or near the nodal points. This paper proposes a new modal strain energy based damage index which can detect and localize the damage using any one of the modes measured and illustrates its application for beam structures. It becomes evident that the proposed strain energy based damage index also has potential for damage quantification.

Women who miscarry : the effectiveness and clinical utility of the Kessler 10 questionnaire in screening for ongoing psychological distress

Background: Early pregnancy loss has been linked to enduring psychological morbidity. Aims: This study aimed to investigate the utility of the Kessler 10 (K10) questionnaire as a brief screening instrument to identify women at risk for the development of psychiatric diagnoses three months post-miscarriage. Method: Participants were 117 consecutive women presenting at a public hospital emergency department and receiving a diagnosis of miscarriage. Main outcome measures: K10 screen for psychological distress and the Structured Clinical Interview for DSM Disorders to determine psychiatric diagnoses. Results: A majority of women (81.2%) experienced elevated levels of distress initially, 24.8% in the very high range. They were not at increased risk of psychiatric diagnoses at three months compared with the general population; however, they were significantly more likely to report subsyndromal symptoms at this time compared with the general population. The baseline K10 score was the only significant predictor of distress at follow-up (r = 0.45, P < 0.001). The receiver operating characteristic curve shows that a cut-off of 14 on the K10 has suitable sensitivity (97%) and specificity (82%) for predicting ongoing psychological distress in women who miscarry. Conclusions: The K10 is effective in identifying women at risk for ensuring psychological symptoms following miscarriage.

The relationship between deformity correction and clinical outcomes after thoracoscopic scoliosis surgery : a prospective series of one hundred patients

Prospective clinical case series of 100 patients receiving thoracoscopic anterior scoliosis correction surgery. The objective was to evaluate the relationship between clinical outcomes of thoracoscopic anterior scoliosis surgery and deformity correction using the Scoliosis Research Society (SRS) outcomes instrument questionnaire. The surgical treatment of scoliosis is quantitatively assessed in the clinic using radiographic measures of deformity correction, as well as the rib hump, but it is important to understand the extent to which these quantitative measures correlate with self-reported improvements in patients’ quality of life following surgery. A series of 100 consecutive adolescent idiopathic scoliosis patients received a single anterior rod via a thoracoscopic approach at the Mater Children’s Hospital, Brisbane, Australia. Patients completed SRS outcomes questionnaires pre-operatively and at 24 months post-operatively. There were 94 females and 6 males with a mean age of 16.1 years. The mean Cobb angle improved from 52º pre-operatively to 25º post-operatively (52%) and the mean rib hump improved from 16º to 8º (51%). The mean total SRS score for the cohort was 99.4/120. None of the deformity related parameters in the multiple regression were significant. However, patients with the lowest post-operative major Cobb angles reported significantly higher SRS scores than those with the highest post-operative Cobb angles, but there was no difference on the basis of rib hump correction. There were no significant differences between patients with either rod fractures or screw-related complications compared to those without complications.

Rights versus reality : the difficulty of providing 'access to English' in Queensland Courts

This report was developed out of a Legal Practitioner on Trust Account Fund grant from the Department of Justice and Attorney-General in Queensland, to review the Aboriginal English in the Courts Handbook. Judges, Magistrates, barristers and court staff were interviewed about the Handbook. The findings extend beyond Aboriginal English into access to English in Queensland Courts. Recommendations are made about language difficulties faced by witnessed and the ability to the courts to respond to them.

Assessment of pile driving refusal using the standard test (SPT)

The design of driven pile foundations involves an iterative process requiring an initial estimate of the refusal level to determine the depth of boreholes for subsequent analyses. Current procedures for determining borehole depths incorporate parameters typically unknown at the investigation stage. Thus, a quantifiable procedure more applicable at this preliminary stage would provide greater confidence in estimating the founding level of driven piles. This paper examines the effectiveness of the Standard Penetration Test (SPT) in directly estimating driven pile refusal levels. A number of significant correlations were obtained between SPT information and pile penetration records demonstrating the potential application of the SPT. Results indicated pile penetration was generally best described as a function of both the pile toe and cumulative shaft SPT values. The influence of the toe SPT increased when piles penetrated rock. A refusal criteria was established from the results to guide both the estimation of borehole depths and likely pile lengths during the design stage.

G4C2C : enabling citizen engagement at arms' length from government

The recognition that Web 2.0 applications and social media sites will strengthen and improve interaction between governments and citizens has resulted in a global push into new e-democracy or Government 2.0 spaces. These typically follow government-to-citizen (g2c) or citizen-to-citizen (c2c) models, but both these approaches are problematic: g2c is often concerned more with service delivery to citizens as clients, or exists to make a show of ‘listening to the public’ rather than to genuinely source citizen ideas for government policy, while c2c often takes place without direct government participation and therefore cannot ensure that the outcomes of citizen deliberations are accepted into the government policy-making process. Building on recent examples of Australian Government 2.0 initiatives, we suggest a new approach based on government support for citizen-to-citizen engagement, or g4c2c, as a workable compromise, and suggest that public service broadcasters should play a key role in facilitating this model of citizen engagement.