Modelling the Effects of Growth and Remodelling on the Density and Structure of Cancellous Bone.

A two-stage model is proposed for investigating remodelling characteristics in bone over time and distance to the growth plate. The first stage comprises a partial differential equation (PDE) for bone density as a function of time and distance from the growth plate. This stage clarifies the contributions to changes in bone density due to remodelling and growth processes and tracks the rate at which new bone emanates from the growth plate.

Swept-Source OCT Mid-Peripheral Retinal Irregularity in Retinal Detachment and Posterior Vitreous Detachment Eyes.

Irregularities in retinal shape have been shown to correlate with axial length, a major risk factor for retinal detachment. To further investigate this association, a comparison was performed of the swept-source optical coherence tomography (SS OCT) peripheral retinal shape of eyes that had either a posterior vitreous detachment (PVD) or vitrectomy for retinal detachment. The objective was to identify a biomarker that can be tested as a predictor for retinal detachment.

Retinal Shape-Based Classification of Retinal Detachment and Posterior Vitreous Detachment Eyes.

Introduction: Retinal detachment is a sight-threatening emergency, with more than half of those affected suffering permanent visual impairment. A diagnostic test to identify eyes at risk before vision is threatened would enable exploration of prophylactic treatment. This report presents the use of irregularities in retinal shape, quantified from optical coherence tomography (OCT) images, as a biomarker for retinal detachment.

The correlation between optical coherence tomography retinal shape irregularity and axial length.

Purpose: To describe the retinal contour in optical coherence tomography (OCT) images, and report the relationship between retinal contour and axial length.

Methods: Retinal contour was defined by the path of the retinal pigment epithelial (RPE) line in macular and extra-macular OCTs of 70 eyes of 70 participants recruited from ophthalmology clinics in South Australia. The shape of this contour was described by the best-fit curvature (K), and Fourier analysis of the difference between K and the RPE.

Evidence of marbling as a single connected entity in beef striploins.

Serial sections of Angus striploins that varied in marbling were analysed in three dimensions to assess potential differences in intramuscular fat structure. The majority of the intramuscular fat appeared to be connected along the 100 mm of muscle in both the highly marbled and less marbled striploins. Thus, rather than having dispersed individual flecks of marbling, the intramuscular fat was a single entity within the striploin.

Characterizing the shape patterns of dimorphic yeast pseudohyphae.

Pseudohyphal growth of the dimorphic yeast is analysed using two-dimensional top-down binary images. The colony morphology is characterized using clustered shape primitives (CSPs), which are learned automatically from the data and thus do not require a list of predefined features or knowledge of the shape. The power of CSPs is demonstrated through the classification of pseudohyphal yeast colonies known to produce different morphologies.

Sampling strategies for approximating patient variability in population-based finite element studies of total hip replacement.

Total hip replacements must be robust to patient variability for long-term success in the population. The challenge during the design process is evaluating an implant in a diverse population but the computational cost of simulating a population of subject-specific finite element (FE) models is not practical. We examined five strategies to generate representative subsets of subjects from a cohort of 103 implanted hip joint FE models to approximate the variability in output metrics.

Nonlinear Modelling for Predicting Patient Presentation Rates for Mass Gatherings.

Unlabelled: IntroductionMass gatherings are common in Australia. The interplay of variables, including crowd density and behavior, weather, and the consumption of alcohol and other drugs, can pose a unique set of challenges to attendees' well-being. On-site health services are available at most mass gatherings and reduce the strain on community health facilities.

Patient Presentation Trends at 15 Mass-Gathering Events in South Australia.

Unlabelled: IntroductionMass gatherings are complex events that present a unique set of challenges to attendees' health and well-being. There are numerous factors that influence the number and type of injuries and illnesses that occur at these events, including weather, event and venue type, and crowd demographics and behavior.ProblemWhile the impact of some factors, such as weather conditions and the availability of alcohol, on patient presentations at mass gatherings have been described previously, the influence of many other variables, including crowd demographics, crowd behavior, and event type, is poorly understood.

A Computational Efficient Method to Assess the Sensitivity of Finite-Element Models: An Illustration With the Hemipelvis.

Assessing the sensitivity of a finite-element (FE) model to uncertainties in geometric parameters and material properties is a fundamental step in understanding the reliability of model predictions. However, the computational cost of individual simulations and the large number of required models limits comprehensive quantification of model sensitivity. To quickly assess the sensitivity of an FE model, we built linear and Kriging surrogate models of an FE model of the intact hemipelvis.

A model for the change of cancellous bone volume and structure over time.

A model is presented for characterizing the process by which cancellous bone changes in volume and structure over time. The model comprises simulations of local changes resulting from individual remodelling events, known as bone multicellular units (BMU), and an ordinary differential equation for connecting the number of remodelling events to real time. The model is validated on micro-CT scans of tibiae of normal rats, estrogen deprived rats and estrogen deprived rats treated with bisphosphonates.

Influence of orthogonal overload on human vertebral trabecular bone mechanical properties.

Unlabelled: The aim of this study was to investigate the effects of overload in orthogonal directions on longitudinal and transverse mechanical integrity in human vertebral trabecular bone. Results suggest that the trabecular structure has properties that act to minimize the decrease of apparent toughness transverse to the primary loading direction.

Introduction: The maintenance of mechanical integrity and function of trabecular structure after overload remains largely unexplored.

Source localisation in a real human head.

Neural activity within the human brain produces electrical potentials that are transmitted through the various tissues of the head to the scalp. A three-dimensional finite difference model has been applied to simulate this process and used as the basis for an inverse model, wherein known potentials on the scalp are used to locate sources of neural activity within the brain. The inverse model uses linear and nonlinear response functions, together with nonlinear regression to determine the source location.