A new registration method based on Log-Euclidean tensor metrics and its application to genetic studies

In structural brain MRI, group differences or changes in brain structures can be detected using Tensor-Based Morphometry (TBM). This method consists of two steps: (1) a non-linear registration step, that aligns all of the images to a common template, and (2) a subsequent statistical analysis. The numerous registration methods that have recently been developed differ in their detection sensitivity when used for TBM, and detection power is paramount in epidemological studies or drug trials. We therefore developed a new fluid registration method that computes the mappings and performs statistics on them in a consistent way, providing a bridge between TBM registration and statistics. We used the Log-Euclidean framework to define a new regularizer that is a fluid extension of the Riemannian elasticity, which assures diffeomorphic transformations. This regularizer constrains the symmetrized Jacobian matrix, also called the deformation tensor. We applied our method to an MRI dataset from 40 fraternal and identical twins, to revealed voxelwise measures of average volumetric differences in brain structure for subjects with different degrees of genetic resemblance.

Automatic clustering of white matter fibers in brain diffusion mri with an application to genetics

To understand factors that affect brain connectivity and integrity, it is beneficial to automatically cluster white matter (WM) fibers into anatomically recognizable tracts. Whole brain tractography, based on diffusion-weighted MRI, generates vast sets of fibers throughout the brain; clustering them into consistent and recognizable bundles can be difficult as there are wide individual variations in the trajectory and shape of WM pathways. Here we introduce a novel automated tract clustering algorithm based on label fusion - a concept from traditional intensity-based segmentation. Streamline tractography generates many incorrect fibers, so our top-down approach extracts tracts consistent with known anatomy, by mapping multiple hand-labeled atlases into a new dataset. We fuse clustering results from different atlases, using a mean distance fusion scheme. We reliably extracted the major tracts from 105-gradient high angular resolution diffusion images (HARDI) of 198 young normal twins. To compute population statistics, we use a pointwise correspondence method to match, compare, and average WM tracts across subjects. We illustrate our method in a genetic study of white matter tract heritability in twins.

MR image-based measurement of rates of change in volumes of brain structures. Part II: Application to a study of Alzheimer's disease and normal aging

We present global and regional rates of brain atrophy measured on serially acquired Tl-weighted brain MR images for a group of Alzheimer's disease (AD) patients and age-matched normal control (NC) subjects using the analysis procedure described in Part I. Three rates of brain atrophy: the rate of atrophy in the cerebrum, the rate of lateral ventricular enlargement and the rate of atrophy in the region of temporal lobes, were evaluated for 14 AD patients and 14 age-matched NC subjects. All three rates showed significant differences between the two groups. However, the greatest separation of the two groups was obtained when the regional rates were combined. This application has demonstrated that rates of brain atrophy, especially in specific regions of the brain, based on MR images can provide sensitive measures for evaluating the progression of AD. These measures will be useful for the evaluation of therapeutic effects of novel therapies for AD.

The Step approach to Message Design and Testing (SatMDT): A conceptual framework to guide the development and evaluation of persuasive health messages

This paper provides an important and timely overview of a conceptual framework designed to assist with the development of message content, as well as the evaluation, of persuasive health messages. While an earlier version of this framework was presented in a prior publication by the authors in 2009, important refinements to the framework have seen it evolve in recent years, warranting the need for an updated review. This paper outlines the Step approach to Message Design and Testing (or SatMDT) in accordance with the theoretical evidence which underpins, as well as empirical evidence which demonstrates the relevance and feasibility, of each of the framework’s steps. The development and testing of the framework have thus far been based exclusively within the road safety advertising context; however, the view expressed herein is that the framework may have broader appeal and application to the health persuasion context.

Application of fragment-based screening to the design of inhibitors of Escherichia coli DsbA

The thiol-disulfide oxidoreductase enzyme DsbA catalyzes the formation of disulfide bonds in the periplasm of Gram-negative bacteria. DsbA substrates include proteins involved in bacterial virulence. In the absence of DsbA, many of these proteins do not fold correctly, which renders the bacteria avirulent. Thus DsbA is a critical mediator of virulence and inhibitors may act as antivirulence agents. Biophysical screening has been employed to identify fragments that bind to DsbA from Escherichia coli. Elaboration of one of these fragments produced compounds that inhibit DsbA activity in vitro. In cell-based assays, the compounds inhibit bacterial motility, but have no effect on growth in liquid culture, which is consistent with selective inhibition of DsbA. Crystal structures of inhibitors bound to DsbA indicate that they bind adjacent to the active site. Together, the data suggest that DsbA may be amenable to the development of novel antibacterial compounds that act by inhibiting bacterial virulence.

Considering the application of biophilic urbanism: A Sustainable Built Environment National Research Centre discussion paper

Biophilic urbanism, or urban design which refl ects human’s innate need for nature in and around and on top of our buildings, stands to make signifi cant contributions to a range of national, state and local government policies related to climate change mitigation and adaptation. Potential benefi ts include reducing the heat island effect, reducing energy consumption for thermal control, enhancing urban biodiversity, improving well being and productivity, improving water cycle management, and assisting in the response to growing needs for densifi cation and revitalisation of cities. This discussion paper will give an overview of the concept of biophilia and consider enablers and disablers to its application to urban planning and design. The paper will present findings from stakeholder engagement related to a consideration of the economics of the use of biophilic elements (direct and indirect). The paper outlines eight strategic areas being considered in the project, including how a ‘daily minimum dose’ of nature can be received through biophilic elements, and how planning and policy can underpin effective biophilic urbanism.

Facilitating sustainable professional part-time work: A question of design?

Despite significant socio-demographic and economic shifts in the contours of work over the past 40 years, there has been surprisingly little change in the way work is designed. Current understandings of the content and structure of jobs are predominantly underpinned by early 20th century theories derived from the manufacturing industry where employees worked independently of each other in stand-alone organisations. It is only in the last 10 years that elaborations and extensions to job/work design theory have been posed, which accommodate some of the fundamental shifts in contemporary work settings, yet these extended frameworks have received little empirical attention. Utilising contemporary features of work design and a sample of professional service workers, the purpose of this study is to examine to what extent and how part-time roles are designed relative to equivalent full-time roles. The findings contribute to efforts to design effective part-time roles that balance organisational and individual objectives.

Knowledge sharing success and resistance in an engineering department: A case study

The centrality of knowledge sharing to organizations’ sustainability has been established. This research explores and illustrates the influences for individual professionals and paraprofessionals – specifically civil engineers and design drafters – to share their deep, personally constructed knowledge, in a public sector provider of railways infrastructure. It investigates the extent to which: (i) knowledge sharing will be positively influenced by the professional identity, values and knowledge culture to achieve organizational and project goals, and; (ii) sharing of deep personal expertise will be influenced by the quality of relational capital among individuals and individual perspectives. It finds that knowledge sharing develops within frameworks established through the alignment among sector, profession and organization values. However, individual behavior is found to be most strongly influenced by the presence and quality of relational capital and individuals’ personal perspectives.

Effects of metal ion concentration on electrodeposited CuZnSn film and its application in kesterite Cu2ZnSnS4solar cells

In this study, effects of concentrations of Cu(II), Zn(II) and Sn(II) ions in the electrolytic bath solution on the properties of electrochemically deposited CuZnSn (CZT) films were investigated. Study of the composition of a CZT film has shown that the metallic content (relative atomic ratio) in the film increased linearly with increase in the metal ion concentration. It is the first time that the relationship of the compositions of the alloy phases in the co-electrodeposited CZT film with the concentration of metal ions has been revealed. The results have confirmed that the formation and content of Cu6Sn5 and Cu5Zn8 alloy phases in the film were directly controlled by the concentration of Cu(II). SEM measurements have shown that Sn(II) has significant impact on film morphology, which became more porous as a result of the larger nucleation size of tin. The changes in the surface properties of the films was also confirmed by chronoamperometry characteristic (i–t) deposition curves. By optimization of metal ion concentrations in the electrolyte solution, a copper-poor and zinc-rich kesterite Cu2ZnSnS4 (CZTS) film was synthesized by the sulfurization of the deposited CZT film. The solar cell with the CZTS film showed an energy conversion efficiency of 2.15% under the illumination intensity of 100 mW cm 2.

Moral rights and their application in Australia: a book review

In Moral Rights and Their Application in Australia, Maree Sainsbury offers a summary of the new moral rights regime established in Australia in 2000. It is a decent guide and handbook to moral rights for legal practitioners, the authors of copyright work, and the users of copyright material. As the author notes: "The Australian moral rights legislation impacts on the rights and obligations of many people in diverse circumstances, from the creator of a highly unique work of art to the designer of a web site incorporating factual information or graphics which someone else has created. Any person creating or dealing with copyright material should be aware of the moral rights implications. This book provides a detailed analysis of the moral rights legislation, while stressing the fundamental provisions. It also provides some useful practical guidance for those who are affected, both in general terms and with respect to the more specific situations outlined above." Maree Sainsbury provides an enjoyable account of the history and nature of moral rights. She charts the romantic, Continental origins of moral rights, and explains their translation to countries, such as Australia and the United States.

Mathematical models for collective cell spreading

Collective cell spreading is frequently observed in development, tissue repair and disease progression. Mathematical modelling used in conjunction with experimental investigation can provide key insights into the mechanisms driving the spread of cell populations. In this study, we investigated how experimental and modelling frameworks can be used to identify several key features underlying collective cell spreading. In particular, we were able to independently quantify the roles of cell motility and cell proliferation in a spreading cell population, and investigate how these roles are influenced by factors such as the initial cell density, type of cell population and the assay geometry.

A dynamic navigation model for unmanned aircraft systems and an application to autonomous front-on environmental sensing and photography using low-cost sensor systems

This paper presents an unmanned aircraft system (UAS) that uses a probabilistic model for autonomous front-on environmental sensing or photography of a target. The system is based on low-cost and readily-available sensor systems in dynamic environments and with the general intent of improving the capabilities of dynamic waypoint-based navigation systems for a low-cost UAS. The behavioural dynamics of target movement for the design of a Kalman filter and Markov model-based prediction algorithm are included. Geometrical concepts and the Haversine formula are applied to the maximum likelihood case in order to make a prediction regarding a future state of a target, thus delivering a new waypoint for autonomous navigation. The results of the application to aerial filming with low-cost UAS are presented, achieving the desired goal of maintained front-on perspective without significant constraint to the route or pace of target movement.

How professional development impacts on experienced teachers' perceptions of their ICT practices

Teachers are at the forefront of Information Communication Technology (ICT) use in schools. Teachers face many challenges and competing priorities such as literacy, numeracy and changing curriculum frameworks and are expected to adopt new ICT practices to improve students¿ outcomes. Effective professional development (PD) methods must be identified and implemented. This research examined two core issues: (1) experienced teachers' perceptions of their ICT practices and (2) how PD courses have affected these practices. This case study and its findings has important implications for the implementation of effective PD in schools.