Continuum mechanics modelling of microfilament networks with different architectures based on molecular investigation of single F-actin

The actin microfilament plays a critical role in many cellular processes including embryonic development, wound healing, immune response, and tissue development. It is commonly organized in the form of networks whose mechanical properties change with changes in their architecture due to cell evolution processes. This paper presents a new nonlinear continuum mechanics model of single filamentous actin (F-actin) that is based on nanoscale molecular simulations. Following this continuum model of the single F-actin, mechanical properties of differently architected lamellipodia are studied. The results provide insight that can contribute to the understanding of the cell edge motions of living cells.

Visualization of thermal characteristics around the absorber tube of a standard parabolic trough thermal collector by 3D simulation

Three dimensional conjugate heat transfer simulation of a standard parabolic trough thermal collector receiver is performed numerically in order to visualize and analyze the surface thermal characteristics. The computational model is developed in Ansys Fluent environment based on some simplified assumptions. Three test conditions are selected from the existing literature to verify the numerical model directly, and reasonably good agreement between the model and the test results confirms the reliability of the simulation. Solar radiation flux profile around the tube is also approximated from the literature. An in house macro is written to read the input solar flux as a heat flux wall boundary condition for the tube wall. The numerical results show that there is an abrupt variation in the resultant heat flux along the circumference of the receiver. Consequently, the temperature varies throughout the tube surface. The lower half of the horizontal receiver enjoys the maximum solar flux, and therefore, experiences the maximum temperature rise compared to the upper part with almost leveled temperature. Reasonable attributions and suggestions are made on this particular type of conjugate thermal system. The knowledge that gained so far from this study will be used to further the analysis and to design an efficient concentrator photovoltaic collector in near future.

A preconditioned Lanczos method for space-fractional reaction-diffusion equations on two-dimensional unstructured meshes

We consider a two-dimensional space-fractional reaction diffusion equation with a fractional Laplacian operator and homogeneous Neumann boundary conditions. The finite volume method is used with the matrix transfer technique of Ilić et al. (2006) to discretise in space, yielding a system of equations that requires the action of a matrix function to solve at each timestep. Rather than form this matrix function explicitly, we use Krylov subspace techniques to approximate the action of this matrix function. Specifically, we apply the Lanczos method, after a suitable transformation of the problem to recover symmetry. To improve the convergence of this method, we utilise a preconditioner that deflates the smallest eigenvalues from the spectrum. We demonstrate the efficiency of our approach for a fractional Fisher’s equation on the unit disk.

Diabetes health program development for Aboriginal and Torres Strait Islander women

According to Australian Health (2008), the area of endocrine, nutritional and metabolic disorders (mainly diabetes) yields the highest cause of death for Indigenous Australian women at 10.1%. Indigenous Brisbane North women’s results reiterate this with slightly higher percentages and are a cause for concern and action due to the noted levels of undiagnosed/unaware Indigenous Brisbane North women with abnormal blood glucose levels, whom participated in the research. A sub-sample of the group (N=17) were piloted to test the feasibility of method of eliciting health information on Indigenous Women within this community. This pilot study revealed the following health information regarding this group of women. 41.2% of Indigenous Brisbane North women were found to have blood glucose levels that were outside normal ranges, however only 29.4% had been diagnosed with diabetes and or endocrine abnormalities. These findings highlight that 11.8% of participants have signs indicating that they may have undiagnosed diabetes or/and pre diabetes juxtaposed to unacceptable endocrine levels compatible with health and wellness. The percentages of Indigenous Brisbane North Women whom have indicated that they have a diagnosis of diabetes have been compared to both National Indigenous peoples percentages and the national percentages for the wider Australian community (all Australians). The rate of diabetes within this population is 9 times that of the wider Australian community and 5 times that of the wider Australian Indigenous community. Data was collected from Indigenous participants on arrival and the attendance numbers of 112 women was recorded for comparison with other current health prevention wellness programs being delivered. Data was also collected through the use of specially designed culturally safe questionnaires undertaken in conjunction with health checks and health service information given to participants.

Social signal processing for pain monitoring using a hidden conditional random field

utomatic pain monitoring has the potential to greatly improve patient diagnosis and outcomes by providing a continuous objective measure. One of the most promising methods is to do this via automatically detecting facial expressions. However, current approaches have failed due to their inability to: 1) integrate the rigid and non-rigid head motion into a single feature representation, and 2) incorporate the salient temporal patterns into the classification stage. In this paper, we tackle the first problem by developing a “histogram of facial action units” representation using Active Appearance Model (AAM) face features, and then utilize a Hidden Conditional Random Field (HCRF) to overcome the second issue. We show that both of these methods improve the performance on the task of pain detection in sequence level compared to current state-of-the-art-methods on the UNBC-McMaster Shoulder Pain Archive.

Transnational field experience : making the familiar strange

This study explores the impact of field experience in Australian primary classrooms on the developing professional identities of Malaysian pre-service teachers. This group of 24 Malaysian students are undertaking their Bachelor of Education in Teaching English as a Foreign Language (BEd TESL) at an Australian university, as part of a transnational twinning program. The globalisation of education has seen an increase in such transnational school experiences for pre-service teachers, with the aim of extending professional experience and intercultural competence by engaging in communities of practice beyond the local (Tsui 2005, Luke 2004). Despite overseas governments, such as Malaysia, having sponsored multimillion dollar twinning programs for their pre-service teachers, there is a lack of research regarding the outcomes of transnational professional practice within such programs. This study adopts a qualitative approach focusing on participants’ narratives as revealed in their reflective writing and through semi-structured interviews. Adopting a Bakhtinian framework, this research uses the concept of ‘voice’ to explore how pre-service teachers negotiate their identities as EFL teachers in response to their lived professional experiences (Bakhtin 1981, 1986). Encountering different cultural and educational practices in their transnational field experiences can lead pre-service teachers to question taken-for-granted practices that they have grown up with. This has been described as a process of making the familiar strange, and can lead to a shift in professional understandings. This study investigates how such questioning occurs and how the transnational field experience is perceived by the participants as contributing to their developing professional identities.

Empirical approach to understand the knowledge management process

Knowledge Management (KM) is a process that focuses on knowledge-related activities to facilitate knowledge creation, capture, transformation and use, with the ultimate aim of leveraging organisations’ intellectual capital to achieve organisational objectives. The KM process receives input from its context (e.g. internal business environment), and produces output (i.e. knowledge). It is argued that the validity of such knowledge should be justified by business performance. The study, this paper reports on, provides enhanced empirical understanding of such an input-process-output relationship through investigating the interactions among different KM activities in the context of how construction organisations in Hong Kong manage knowledge. To this end, a theoretical framework along with a number of hypotheses are proposed and empirically tested through correlation, regression and path analyses. A questionnaire survey was administered to a sample of construction contractors operating in Hong Kong to facilitate testing the proposed relationships. More than 140 respondents from 99 organisations responded to the survey. The study findings demonstrate that both organisational and technical environments have the potential to predict the intensity of KM activities. Furthermore, different categories of KM activities interact with each other, and collectively they could be used to predict business performance.

The role of, and key considerations for, advertising campaigns and educational awareness workshops within the work-related road safety context

Australian and international evidence suggests that, in the work-related driving context, road crashes account for a substantial number of occupational incidents. In the attempt to reduce injury and improve safety, organisations may implement an array of strategies and interventions ranging from policy development and implementation, vehicle selection and incident monitoring through to education and awareness-raising. This conceptual paper discusses aspects relating to the latter collection of interventions and, in particular, the role, and some key considerations with respect to the content and dissemination, of advertising campaigns and educational awareness workshops. In relation to advertising campaigns, this paper discusses how some of the overarching principles associated with advertising in the broader general community road safety strategy also apply within the work-related road safety context. Specifically, advertising campaigns/materials should be viewed as a key component within a dedicated organisational approach to road (driver) safety. This dedicated approach would need to comprise of a number, and varied array, of strategies. In addition, the content of, and medium/s (e.g., posters) by which to deliver such advertising campaigns, cannot be addressed by a one-size-fits all approach but, rather, requires careful consideration of the needs as well as characteristics of specific organisations and their driver fleet. The paper provides a summary of some key considerations when devising an advertising campaign, including the nature of campaign/message content as well as the processes by which to devise and refine such content. In relation to driver education awareness workshops, this paper outlines the key considerations for delivering a series of workshops specifically aimed at occupational driving within the organisational context. A case study approach will be utilised to demonstrate the manner in which educational awareness workshops can compliment successful advertising campaigns promoting safer work related driving through better risk management practice. Research underpinning the development of driver behaviour modification tools incorporated within the workshops will also be discussed along with the mechanisms utilised to encourage improvements in driver monitoring and behaviour. In an effort to assist organisations with their continual search for cost-effective approaches which may, ultimately, contribute to improvements in driver behaviour and safety, the current paper offers some clear and practical suggestions in relation to the development and dissemination of two types of interventions, advertising campaigns and education awareness workshops.

Translating vision research into policy and practice to improve visibility, and hence safety, of road workers at night

This case study report describes the stages involved in the translation of research on night-time visibility into standards for the safety clothing worn by roadworkers. Vision research demonstrates that when lights are placed on the moveable joints of the body and the person moves in a dark setting, the phenomenon known as “biological motion or biomotion” occurs, enabling rapid and accurate recognition of the human form although only the lights can be seen. QUT was successful in gaining funding from the Australian Research Council for a Linkage grant due to the support of the predecessors of the Queensland Department of Transport and Main Roads (TMR) to research the biomotion effect in on-road settings using materials that feature in roadworker clothing. Although positive results were gained, the process of translating the research results into policy, practices and standards relied strongly on the supportive efforts of TMR staff engaged in the review and promulgation of national standards. The ultimate result was the incorporation of biomotion marking into AS/NZS 4602.1 2011. The experiences gained in this case provide insights into the processes involved in translating research into practice.

Safety culture in supply chains : 'Customer is king'

Despite the presence of many regulations governing the operation of heavy vehicles and supply chains in Australia, the truck driving sector continues to have the highest incidence of fatal injuries compared to all other industries. The working environment has been the focus of attention by safety researchers during the past few decades, with particular consideration been given to the concept ‘safety culture’ and how to maintain, modify and advance responses to occupational risk. One important aspect of the heavy industry which sets it apart is the existence of cultural or sub-cultural influences at an industry wide and occupation-specific level rather than organisational level. This paper reports on the findings of stakeholder’s perceptions of the influences of power and control, and culture on industry safety. In-depth structured interviews were conducted during 2011 with Australian industry stakeholders (n=31). The questioning surrounded decision-making processes with regards to identifying risks, self-monitoring and reducing risky activities; as well as how power-affected relationships may influence the operational performance of supply chains and impacts on driver safety. One of the most significant findings from these interviews relates to the notion of power. The perception that the ‘Customer is King’ was widely viewed, with the majority of stakeholders believing that there exists a ‘master slave mentality’ in the industry. There appears to be great frustration in the industry as to the apparent immunity of customers (particularly retail supply chains) to their responsibilities. There was also a strong perception that the customer holds the balance of power by covertly employing remuneration-related incentives and pressures. Smaller trucking companies are perceived as being more vulnerable to the pressure of customer expectations.

Redland city council fleet safety initiative : the road to recovery

Due to the propensity of fleet incidents, poor organisational survey results and a lack of fleet safety systems, it was evident that Redland City Council were underperforming, experiencing a variety of work related road safety issues and possessed a low fleet safety culture. As a result of an audit process, and the identification of gaps in organisational process within the fleet safety area Redland City Council embarked upon the enormous task of strategically implementing initiatives and improving fleet safety across the organisation. The strategies utilised within the Redland City Council Fleet Safety Initiative were implemented utilising a systematic process and adopted a multi-disciplinary approach to improve overall fleet safety. Organisational initiatives targeting fleet safety aspects have benefited the Council by the development of an improved organisational culture, including safer driver attitudes and behaviour. This paper outlines the road to recovery for Redland City Council in relation to its fleet safety initiatives.

Cohesive zone modelling of mineralized collagen fibril arrays in bending

Hard biological materials such as bone possess superior material properties of high stiffness and toughness. Two unique characteristics of bone microstructure are a large aspect ratio of mineralized collagen fibrils (MCF), and an extremely thin and large area of extrafibrillar protein matrix located between the MCF. The objective of this study is to investigate the effects of: (1) MCF aspect ratio, and (2) energy dissipation in extrafibrillar protein matrix on the mechanical behaviour of MCF arrays. In this study, notched specimens of MCF arrays in extrafibrillar protein matrix are subjected to bending. Cohesive zone model was implemented to simulate the failure of extrafibrillar protein matrix. The study reveals that the MCF array with a higher MCF aspect ratio and the MCF array with a higher protein energy dissipation in the interface direction are able to sustain a higher bending force and dissipate higher energy.

Comparing cooperative and non-cooperative crash risk assessment

Cooperative Systems provide, through the multiplication of information sources over the road, a lot of potential to improve the assessment of the road risk describing a particular driving situation. In this paper, we compare the performance of a cooperative risk assessment approach against a non-cooperative approach; we used an advanced simulation framework, allowing for accurate and detailed, close-to-reality simulations. Risk is estimated, in both cases, with combinations of indicators based on the TTC. For the non-cooperative approach, vehicles are equipped only with an AAC-like forward-facing ranging sensor. On the other hand, for the cooperative approach, vehicles share information through 802.11p IVC and create an augmented map representing their environment; risk indicators are then extracted from this map. Our system shows that the cooperative risk assessment provides a systematic increase of forward warning to most of the vehicles involved in a freeway emergency braking scenario, compared to a non-cooperative system.

A pre-treatment verification tool for IMRT based on EPID measurements and a GEANT4 back projection application

The aim of this work is to develop software that is capable of back projecting primary fluence images obtained from EPID measurements through phantom and patient geometries in order to calculate 3D dose distributions. In the first instance, we aim to develop a tool for pretreatment verification in IMRT. In our approach, a Geant4 application is used to back project primary fluence values from each EPID pixel towards the source. Each beam is considered to be polyenergetic, with a spectrum obtained from Monte Carlo calculations for the LINAC in question. At each step of the ray tracing process, the energy differential fluence is corrected for attenuation and beam divergence. Subsequently, the TERMA is calculated and accumulated to an energy differential 3D TERMA distribution. This distribution is then convolved with monoenergetic point spread kernels, thus generating energy differential 3D dose distributions. The resulting dose distributions are accumulated to yield the total dose distribution, which can then be used for pre-treatment verification of IMRT plans. Preliminary results were obtained for a test EPID image comprised of 100 9 100 pixels of unity fluence. Back projection of this field into a 30 cm9 30 cm 9 30 cm water phantom was performed, with TERMA distributions obtained in approximately 10 min (running on a single core of a 3 GHz processor). Point spread kernels for monoenergetic photons in water were calculated using a separate Geant4 application. Following convolution and summation, the resulting 3D dose distribution produced familiar build-up and penumbral features. In order to validate the dose model we will use EPID images recorded without any attenuating material in the beam for a number of MLC defined square fields. The dose distributions in water will be calculated and compared to TPS predictions.