Translating tissue engineering technology platforms into cancer research

Technology platforms originally developed for tissue engineering applications produce valuable models that mimic three-dimensional (3D) tissue organization and function to enhance the understanding of cell/tissue function under normal and pathological situations. These models show that when replicating physiological and pathological conditions as closely as possible investigators are allowed to probe the basic mechanisms of morphogenesis, differentiation and cancer. Significant efforts investigating angiogenetic processes and factors in tumorigenesis are currently undertaken to establish ways of targeting angiogenesis in tumours. Anti-angiogenic agents have been accepted for clinical application as attractive targeted therapeutics for the treatment of cancer. Combining the areas of tumour angiogenesis, combination therapies and drug delivery systems is therefore closely related to the understanding of the basic principles that are applied in tissue engineering models. Studies with 3D model systems have repeatedly identified complex interacting roles of matrix stiffness and composition, integrins, growth factor receptors and signalling in development and cancer. These insights suggest that plasticity, regulation and suppression of these processes can provide strategies and therapeutic targets for future cancer therapies. The historical perspective of the fields of tissue engineering and controlled release of therapeutics, including inhibitors of angiogenesis in tumours is becoming clearly evident as a major future advance in merging these fields. New delivery systems are expected to greatly enhance the ability to deliver drugs locally and in therapeutic concentrations to relevant sites in living organisms. Investigating the phenomena of angiogenesis and anti-angiogenesis in 3D in vivo models such as the Arterio-Venous (AV) loop mode in a separated and isolated chamber within a living organism adds another significant horizon to this perspective and opens new modalities for translational research in this field.

Downtime reduction analysis of the Australia Post flat mail optical character reader

Machine downtime, whether planned or unplanned, is intuitively costly to manufacturing organisations, but is often very difficult to quantify. The available literature showed that costing processes are rarely undertaken within manufacturing organisations. Where cost analyses have been undertaken, they generally have only valued a small proportion of the affected costs, leading to an overly conservative estimate. This thesis aimed to develop a cost of downtime model, with particular emphasis on the application of the model to Australia Post’s Flat Mail Optical Character Reader (FMOCR). The costing analysis determined a cost of downtime of $5,700,000 per annum, or an average cost of $138 per operational hour. The second section of this work focused on the use of the cost of downtime to objectively determine areas of opportunity for cost reduction on the FMOCR. This was the first time within Post that maintenance costs were considered along side of downtime for determining machine performance. Because of this, the results of the analysis revealed areas which have historically not been targeted for cost reduction. Further exploratory work was undertaken on the Flats Lift Module (FLM) and Auto Induction Station (AIS) Deceleration Belts through the comparison of the results against two additional FMOCR analysis programs. This research has demonstrated the development of a methodical and quantifiable cost of downtime for the FMOCR. This has been the first time that Post has endeavoured to examine the cost of downtime. It is also one of the very few methodologies for valuing downtime costs that has been proposed in literature. The work undertaken has also demonstrated how the cost of downtime can be incorporated into machine performance analysis with specific application to identifying high costs modules. The outcome of this report has both been the methodology for costing downtime, as well as a list of areas for cost reduction. In doing so, this thesis has outlined the two key deliverables presented at the outset of the research.

Postpartum fatigue and driving : relating experiences, thoughts and opinions 12 weeks post-birth

Fatigue in the postnatal period is such a common experience for most mothers that the term ‘postpartum fatigue’ (PPF) has been coined to describe it. When new mothers experience extreme fatigue, it follows that their physical health, mental health, and social-wellbeing is negatively affected. It is interesting to note that there is a distinct lack of empirical investigations focusing on the link between PPF and increased risk of injury; particularly when the links between fatigue and increased risk of road crashes are well documented. The purpose of this investigation was to undertake pilot research to develop an understanding of the duration of PPF and the performance impairments experienced by new mothers when involved in safety-sensitive activities, such as driving a motor vehicle. Semi-structured interviews were undertaken with women (N = 24) at 12 weeks postpartum living in South-east Queensland, Australia. Key themes were identified; with a particular emphasis towards understanding the link between the participant’s experience of postpartum fatigue and the impact this has on their overall cognitive and physiological functioning, as well as their experience of the driving task. Further, sleep/wake data was collected and using the Karolinska Sleepiness Scale (KSS) the potential crash risk for this group of mothers is discussed. It is proposed that the findings of this investigation could be used to improve current knowledge among new mothers and practitioners regarding the mechanisms and consequences of fatigue and to inform interventions that lead to a decreased risk of injury associated with postpartum fatigue.

Eye-movements and visual imagery : a working memory approach to the treatment of post-traumatic stress disorder

It has been claimed that the symptoms of post-traumatic stress disorder (PTSD) can be ameliorated by eye-movement desensitization-reprocessing therapy (EMD-R), a procedure that involves the individual making saccadic eye-movements while imagining the traumatic event. We hypothesized that these eye-movements reduce the vividness of distressing images by disrupting the function of the visuospatial sketchpad (VSSP) of working memory, and that by doing so they reduce the intensity of the emotion associated with the image. This hypothesis was tested by asking non-PTSD participants to form images of neutral and negative pictures under dual task conditions. Their images were less vivid with concurrent eye-movements and with a concurrent spatial tapping task that did not involve eye-movements. In the first three experiments, these secondary tasks did not consistently affect participants' emotional responses to the images. However, Expt 4 used personal recollections as stimuli for the imagery task, and demonstrated a significant reduction in emotional response under the same dual task conditions. These results suggest that, if EMD-R works, it does so by reducing the vividness and emotiveness of traumatic images via the VSSP of working memory. Other visuospatial tasks may also be of therapeutic value.

Post-buckling Strength of LiteSteel Beams in Shear

This paper presents the details of experimental and numerical studies on the shear behaviour of a recently developed, cold-formed steel beam known as LiteSteel Beam (LSB). The LSB sections are produced by a patented manufacturing process involving simultaneous cold-forming and electric resistance welding. It has a unique shape of a channel beam with two rectangular hollow flanges. Recent research has demonstrated the presence of increased shear capacity of LSBs due to the additional fixity along the web to flange juncture, but the current design rules ignore this effect. Therefore they were modified by including a higher elastic shear buckling coefficient. In the present study, the ultimate shear capacity results obtained from the experimental and numerical studies of 10 different LSB sections were compared with the modified shear capacity design rules. It was found that they are still conservative as they ignore the presence of post-buckling strength. Therefore the design rules were further modified to include the available post-buckling strength. Suitable design rules were also developed under the direct strength method format. This paper presents the details of this study and the results including the final design rules for the shear capacity of LSBs.