Anatomical MR imaging of long bones : comparative performance of MRI at 1.5 T and 3 T

The current gold standard for the design of orthopaedic implants is 3D models of long bones obtained using computed tomography (CT). However, high-resolution CT imaging involves high radiation exposure, which limits its use in healthy human volunteers. Magnetic resonance imaging (MRI) is an attractive alternative for the scanning of healthy human volunteers for research purposes. Current limitations of MRI include difficulties of tissue segmentation within joints and long scanning times. In this work, we explore the possibility of overcoming these limitations through the use of MRI scanners operating at a higher field strength. We quantitatively compare the quality of anatomical MR images of long bones obtained at 1.5 T and 3 T and optimise the scanning protocol of 3 T MRI. FLASH images of the right leg of five human volunteers acquired at 1.5 T and 3 T were compared in terms of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The comparison showed a relatively high CNR and SNR at 3 T for most regions of the femur and tibia, with the exception of the distal diaphyseal region of the femur and the mid diaphyseal region of the tibia. This was accompanied by an ~65% increase in the longitudinal spin relaxation time (T1) of the muscle at 3 T compared to 1.5 T. The results suggest that MRI at 3 T may be able to enhance the segmentability and potentially improve the accuracy of 3D anatomical models of long bones, compared to 1.5 T. We discuss how the total imaging times at 3 T can be kept short while maximising the CNR and SNR of the images obtained.

Eyes on 3D-Current 3D biomimetic disease concept models and potential applications in age-related macular degeneration

Three dimensional cellular models that mimic disease are being increasingly investigated and have opened an exciting new research area into understanding pathomechanisms. The advantage of 3D in vitro disease models is that they allow systematic and in-depth studies of physiological and pathophysiological processes with less costs and ethical concerns that have arisen with animal models. The purpose of the 3D approach is to allow crosstalk between cells and microenvironment, and with cues from the microenvironment, cells can assemble their niche similar to in vivo conditions. The use of 3D models for mimicking disease processes such as cancer, osteoarthritis etc., is only emerging and allows multidisciplinary teams consisting of tissue engineers, biologist biomaterial scientists and clinicians to work closely together. While in vitro systems require rigorous testing before they can be considered as replicates of the in vivo model, major steps have been made, suggesting that they will become powerful tools for studying physiological and pathophysiological processes. This paper aims to summarize some of the existing 3D models and proposes a novel 3D model of the eye structures that are involved in the most common cause of blindness in the Western World, namely age-related macular degeneration (AMD).

Scaffold percolative efficiency : in vitro evaluation of the structural criterion for electrospun mats

Fibrous scaffolds of engineered structures can be chosen as promising porous environments when an approved criterion validates their applicability for a specific medical purpose. For such biomaterials, this paper sought to investigate various structural characteristics in order to determine whether they are appropriate descriptors. A number of poly(3-hydroxybutyrate) scaffolds were electrospun; each of which possessed a distinguished architecture when their material and processing conditions were altered. Subsequent culture of mouse fibroblast cells (L929) was carried out to evaluate the cells viability on each scaffold after their attachment for 24 h and proliferation for 48 and 72 h. The scaffolds’ porosity, pores number, pores size and distribution were quantified and none could establish a relationship with the viability results. Virtual reconstruction of the mats introduced an authentic criterion, “Scaffold Percolative Efficiency” (SPE), with which the above descriptors were addressed collectively. It was hypothesized to be able to quantify the efficacy of fibrous scaffolds by considering the integration of porosity and interconnectivity of the pores. There was a correlation of 80% as a good agreement between the SPE values and the spectrophotometer absorbance of viable cells; a viability of more than 350% in comparison to that of the controls.

Organizational culture in airworthiness management programmes : extending an existing measurement model

All civil and private aircraft are required to comply with the airworthiness standards set by their national airworthiness authority and throughout their operational life must be in a condition of safe operation. Aviation accident data shows that over 20% of all fatal accidents in aviation are due to airworthiness issues, specifically aircraft mechanical failures. Ultimately it is the responsibility of each registered operator to ensure that their aircraft remain in a condition of safe operation, and this is done through both effective management of airworthiness activities and the effective programme governance of safety outcomes. Typically, the projects within these airworthiness management programmes are focused on acquiring, modifying and maintaining the aircraft as a capability supporting the business. Programme governance provides the structure through which the goals and objectives of airworthiness programmes are set along with the means of attaining them. Whilst the principal causes of failures in many programmes can be traced to inadequate programme governance, many of the failures in large-scale projects can have their root causes in the organizational culture and more specifically in the organizational processes related to decision-making. This paper examines the primary theme of project and programme-based enterprises, and introduces a model for measuring organizational culture in airworthiness management programmes using measures drawn from 211 respondents in Australian airline programmes. The paper describes the theoretical perspectives applied to modifying an original model to specifically focus it on measuring the organizational culture of programmes for managing airworthiness; identifying the most important factors needed to explain the relationship between the measures collected, and providing a description of the nature of these factors. The paper concludes by identifying a model that best describes the organizational culture data collected from seven airworthiness management programmes.

Effective community engagement for project success : building professionals as active participants during the construction phase of projects

Growing community concerns about the ecological, social, cultural and economic impact of housing and urban projects poses new challenges for those who have to deliver them. It is important that these concerns are addressed as part of the community engagement processes on projects. Community engagement is traditionally perceived as the purview of planners and disconnected from the building construction process. This is despite most project approval processes mandating on-going community engagement over the project’s entire lifetime. There is evidence that point to a culture of ambiguity and ambivalence among building professionals about their roles, responsibilities and expectations of community engagement during the construction phase of projects. This has contributed to a culture of distrust between communities and the construction industry. There is a clear need to build capacity among building professionals to empower them as active participants in community engagement processes which can promote better project outcomes and minimise delays and conflicts. This paper describes a process that utilises the Theory of Planned Behaviour as a framework to equip building professionals with the skills they need to engage effectively with local communities during the construction phase of projects.

Exercise and Cellular Mechanisms of Muscle Injury

The general aim of this book is to provide a comprehensive summary of the characteristics of exercise-induced muscle damage and the mechanisms of tissue inflammation. The authors present a large amount of our own original data and have summarised the research of others.

Transcriptome analysis of neutrophils after endurance exercise reveals novel signaling mechanisms in the immune response to physiological stress

Neutrophils serve as an intriguing model for the study of innate immune cellular activity induced by physiological stress. We measured changes in the transcriptome of circulating neutrophils following an experimental exercise trial (EXTRI) consisting of 1 h of intense cycling immediately followed by 1 h of intense running. Blood samples were taken at baseline, 3 h, 48 h, and 96 h post-EXTRI from eight healthy, endurance-trained, male subjects. RNA was extracted from isolated neutrophils. Differential gene expression was evaluated using Illumina microarrays and validated with quantitative PCR. Gene set enrichment analysis identified enriched molecular signatures chosen from the Molecular Signatures Database. Blood concentrations of muscle damage indexes, neutrophils, interleukin (IL)-6 and IL-10 were increased (P < 0.05) 3 h post-EXTRI. Upregulated groups of functionally related genes 3 h post-EXTRI included gene sets associated with the recognition of tissue damage, the IL-1 receptor, and Toll-like receptor (TLR) pathways (familywise error rate, P value < 0.05). The core enrichment for these pathways included TLRs, low-affinity immunoglobulin receptors, S100 calcium binding protein A12, and negative regulators of innate immunity, e.g., IL-1 receptor antagonist, and IL-1 receptor associated kinase-3. Plasma myoglobin changes correlated with neutrophil TLR4 gene expression (r = 0.74; P < 0.05). Neutrophils had returned to their nonactivated state 48 h post-EXTRI, indicating that their initial proinflammatory response was transient and rapidly counterregulated. This study provides novel insight into the signaling mechanisms underlying the neutrophil responses to endurance exercise, suggesting that their transcriptional activity was particularly induced by damage-associated molecule patterns, hypothetically originating from the leakage of muscle components into the circulation.

Communication and the casualisation of nursing : a critical ethnography

The contemporary working environment is being rapidly reshaped by technological, industrial and political forces. Increased global competitiveness and an emphasis on productivity have led to the appearance of alternative methods of employment, such as part-time, casual and itinerant work, allowing greater flexibility. This allows for the development of a core permanent staff and the simultaneous utilisation of casual staff according to business needs. Flexible workers across industries are generally referred to as the non-standard workforce and full-time permanent workers as the standard workforce. Even though labour flexibility favours the employer, increased opportunity for flexible work has been embraced by women for many reasons, including the gender struggle for greater economic independence and social equality. Consequently, the largely female nursing industry, both nationally and internationally, has been caught up in this wave of change. This ageing workforce has been at the forefront of the push for flexibility with recent figures showing almost half the nursing workforce is employed in non-standard capacity. In part, this has allowed women to fulfil caring roles outside their work, to ease off nearing retirement and to supplement the family income. More significantly, however, flexibility has developed as an economic management initiative, as a strategy for cost constraint. The result has been the development of a dual workforce and as suggested by Pocock, Buchanan and Campbell (2004), associated deep-seated resentment and the marginalisation of part-time and casual workers by their full-time colleagues and managers. Additionally, as nursing currently faces serious recruitment and retention problems there is urgent need to understand the factors which are underlying present discontent in the nursing profession. There is an identified gap in nursing knowledge surrounding the issues relating to recruitment and retention. Communication involves speaking, listening, reading and writing and is an interactive process which is central to the lives of humans. Workplace communication refers to human interaction, information technology, and multimedia and print. It is the means to relationship building between workers, management, and their external environment and is critical to organisational effectiveness. Communication and language are integral to nursing performance (Hall, 2005), in twenty-four hour service however increasing fragmentation due to part-time and casual work in the nursing industry means that effective communication management has become increasingly difficult. More broadly it is known that disruption to communication systems impacts negatively on consumer outcomes. Because of this gap in understanding how nurses view their contemporary nursing world, an interpretative ethnographic study which progressed to a critical ethnographic study, based on the conceptual framework of constructionism and interpretativism was used. The study site was a division within an acute health care facility, and the relationship between increasing casualisation of the nursing workforce and the experiences of communication of standard and non-standard nurses was explored. For this study, full-time standard nurses were those employed to work in a specific unit for forty hours per week. Non-standard nurses were those employed part-time in specific units or those nurses employed to work as relief pool nurses for shift short falls where needed. Nurses employed by external agencies, but required to fill in for shifts at the facility were excluded from this research. This study involved an analysis of observational, interview and focus group data of standard and non-standard nurses within this facility. Three analytical findings - the organisation of nursing work; constructing the casual nurse as other; and the function of space, situate communication within a broader discussion about non-standard work and organisational culture. The study results suggest that a significant culture of marginalisation exists for nurses who work in a non-standard capacity and that this affects communication for nurses and has implications for the quality of patient care. The discussion draws on the seven elements of marginalisation described by Hall, Stephen and Melius (1994). The arguments propose that these elements underpin a culture which supports remnants of the historically gendered stereotype "the good nurse" and these cultural values contribute to practices and behaviour which marginalise all nurses, particularly those who work less than full-time. Gender inequality is argued to be at the heart of marginalising practices because of long standing subordination of nurses by the powerful medical profession, paralleling historical subordination of women in society. This has denied nurses adequate representation and voice in decision making. The new knowledge emanating from this study extends current knowledge of factors surrounding recruitment and retention and as such contributes to an understanding of the current and complex nursing environment.

Effect of CT electron density identification on Monte Carlo simulations of radiotherapeutic treatments

Introduction: The accurate identification of tissue electron densities is of great importance for Monte Carlo (MC) dose calculations. When converting patient CT data into a voxelised format suitable for MC simulations, however, it is common to simplify the assignment of electron densities so that the complex tissues existing in the human body are categorized into a few basic types. This study examines the effects that the assignment of tissue types and the calculation of densities can have on the results of MC simulations, for the particular case of a Siemen’s Sensation 4 CT scanner located in a radiotherapy centre where QA measurements are routinely made using 11 tissue types (plus air). Methods: DOSXYZnrc phantoms are generated from CT data, using the CTCREATE user code, with the relationship between Hounsfield units (HU) and density determined via linear interpolation between a series of specified points on the ‘CT-density ramp’ (see Figure 1(a)). Tissue types are assigned according to HU ranges. Each voxel in the DOSXYZnrc phantom therefore has an electron density (electrons/cm3) defined by the product of the mass density (from the HU conversion) and the intrinsic electron density (electrons /gram) (from the material assignment), in that voxel. In this study, we consider the problems of density conversion and material identification separately: the CT-density ramp is simplified by decreasing the number of points which define it from 12 down to 8, 3 and 2; and the material-type-assignment is varied by defining the materials which comprise our test phantom (a Supertech head) as two tissues and bone, two plastics and bone, water only and (as an extreme case) lead only. The effect of these parameters on radiological thickness maps derived from simulated portal images is investigated. Results & Discussion: Increasing the degree of simplification of the CT-density ramp results in an increasing effect on the resulting radiological thickness calculated for the Supertech head phantom. For instance, defining the CT-density ramp using 8 points, instead of 12, results in a maximum radiological thickness change of 0.2 cm, whereas defining the CT-density ramp using only 2 points results in a maximum radiological thickness change of 11.2 cm. Changing the definition of the materials comprising the phantom between water and plastic and tissue results in millimetre-scale changes to the resulting radiological thickness. When the entire phantom is defined as lead, this alteration changes the calculated radiological thickness by a maximum of 9.7 cm. Evidently, the simplification of the CT-density ramp has a greater effect on the resulting radiological thickness map than does the alteration of the assignment of tissue types. Conclusions: It is possible to alter the definitions of the tissue types comprising the phantom (or patient) without substantially altering the results of simulated portal images. However, these images are very sensitive to the accurate identification of the HU-density relationship. When converting data from a patient’s CT into a MC simulation phantom, therefore, all possible care should be taken to accurately reproduce the conversion between HU and mass density, for the specific CT scanner used. Acknowledgements: This work is funded by the NHMRC, through a project grant, and supported by the Queensland University of Technology (QUT) and the Royal Brisbane and Women's Hospital (RBWH), Brisbane, Australia. The authors are grateful to the staff of the RBWH, especially Darren Cassidy, for assistance in obtaining the phantom CT data used in this study. The authors also wish to thank Cathy Hargrave, of QUT, for assistance in formatting the CT data, using the Pinnacle TPS. Computational resources and services used in this work were provided by the HPC and Research Support Group, QUT, Brisbane, Australia.

Characterisation of enterovirus 71 replication kinetics in human colorectal cell line, HT29

Hand, Foot and Mouth Disease (HFMD), a contagious viral disease that commonly affects infants and children with blisters and flu like symptoms, is caused by a group of enteroviruses such as Enterovirus 71 (EV71) and coxsackievirus A16 (CA16). However some HFMD caused by EV71 may further develop into severe neurological complications such as encephalitis and meningitis. The route of transmission was postulated that the virus transmit from one person to another through direct contact of vesicular fluid or droplet from the infected or via faecal-oral route. To this end, this study utilised a human colorectal adenocarcinoma cell line (HT29) with epithelioid morphology as an in vitro model for the investigation of EV71 replication kinetics. Using qPCR, viral RNA was first detected in HT29 cells as early as 12 h post infection (hpi) while viral protein was first detected at 48 hpi. A significant change in HT29 cells’ morphology was also observed after 48 hpi. Furthermore HT29 cell viability also significantly decreased at 72 hpi. Together, data from this study demonstrated that co-culture of HT29 with EV71 is a useful in vitro model to study the pathogenesis of EV71

Towards university lectures' conceptions of student learning

A range of studies conducted since the late 1970s have sought to describe students' conceptions of learning, and more recently, teachers' conceptions of teaching. These studies, using what has come to be known as the phenomenographic approach, have identified conceptions of teaching, and conceptions of learning which have had a significant impact on the teaching-learning culture of higher education institutions in many parts of the world. The study reported here contributes to our understanding of student learning, describing it from the viewpoint of lectures from a range of disciplines. From the viewpoint of these lectures student learning was seen variously as: acquiring knowledge through the use of study skills; the absorption of new knowledge and being able to explain and apply it; the development of thinking skills and the ability to reason; developing the competencies of beginning professionals; changing personal attitudes, beliefs or behaviours in responding to different phenomena; and a participative pedagogic experience. The relationship between these conceptions and previously identified conceptions of teaching and learning is discussed.

A case study of pedagogical responses to internationalisation at a faith-based secondary school in Australia

This case study investigated pedagogical responses to internationalisation by a faith-based secondary school in Australia. Using social constructivism as the theoretical framework the study examined teaching and learning for culturally and linguistically diverse students. Data generated through questionnaires, focus groups, individual interviews and document archives were analysed and interpreted using thematic analysis. The findings showed that teachers believed themselves to be ill-equipped to teach international students. Their concerns centred on a lack of explicit pedagogical, cultural and linguistic knowledge to help the students acculturate and learn. Recommendations include the dissemination of school policies to teachers, intentional staff collaboration and professional development to address the teachers’ needs for internationalisation.

Outdoor worker sun protection project : a comprehensive applied research project to demonstrate the effectiveness of sun protection measures which influence high risk outdoor workers in Queensland to adopt sun safe behaviour practices 2010 – 2013

The QUT Outdoor Worker Sun Protection (OWSP) project undertook a comprehensive applied health promotion project to demonstrate the effectiveness of sun protection measures which influence high risk outdoor workers in Queensland to adopt sun safe behaviours. The three year project (2010-2013) was driven by two key concepts: 1) The hierarchy of control, which is used to address risks in the workplace, advocates for six control measures that need to be considered in order of priority (refer to Section 3.4.2); and 2) the Ottawa Charter which recommends five action means to achieve health promotion (refer to Section 2.1). The project framework was underpinned by a participatory action research approach that valued peoples’ input, took advantage of existing skills and resources, and stimulated innovation (refer to Section 4.2). Fourteen workplaces (small and large) with a majority outdoor workforce were recruited across regional Queensland (Darling Downs, Northwest, Mackay and Cairns) from four industries types: 1) building and construction, 2) rural and farming, 3) local government, and 4) public sector. A workplace champion was identified at each workplace and was supported (through resource provision, regular contact and site visits) over a 14 to 18 month intervention period to make sun safety a priority in their workplace. Employees and employers were independently assessed for pre- and postintervention sun protection behaviours. As part of the intervention, an individualised sun safety action plan was developed in conjunction with each workplace to guide changes across six key strategy areas including: 1) Policy (e.g., adopt sun safety practices during all company events); 2) Structural and environmental (e.g., shade on worksites; eliminate or minimise reflective surfaces); 3) Personal protective equipment (PPE) (e.g., trial different types of sunscreens, or wide-brimmed hats); 4) Education and awareness (e.g., include sun safety in inductions and toolbox talks; send reminder emails or text messages to workers);5) Role modelling (e.g., by managers, supervisors, workplace champions and mentors); and 6) Skin examinations (e.g., allow time off work for skin checks). The participatory action process revealed that there was no “one size fits all” approach to sun safety in the workplace; a comprehensive, tailored approach was fundamental. This included providing workplaces with information, resources, skills, know how, incentives and practical help. For example, workplaces engaged in farming complete differing seasonal tasks across the year and needed to prepare for optimal sun safety of their workers during less labour intensive times. In some construction workplaces, long pants were considered a trip hazard and could not be used as part of a PPE strategy. Culture change was difficult to achieve and workplace champions needed guidance on the steps to facilitate this (e.g., influencing leaders through peer support, mentoring and role modelling). With the assistance of the project team the majority of workplaces were able to successfully implement the sun safety strategies contained within their action plans, up skilling them in the evidence for sun safety, how to overcome barriers, how to negotiate with all relevant parties and assess success. The most important enablers to the implementation of a successful action plan were a pro-active workplace champion, strong employee engagement, supportive management, the use of highly visual educational resources, and external support (provided by the project team through regular contact either directly through phone calls or indirectly through emails and e-newsletters). Identified barriers included a lack of time, the multiple roles of workplace champions, (especially among smaller workplaces), competing issues leading to a lack of priority for sun safety, the culture of outdoor workers, and costs or budgeting constraints. The level of sun safety awareness, knowledge, and sun protective behaviours reported by the workers increased between pre-and post-intervention. Of the nine sun protective behaviours that were assessed, the largest changes reported included a 26% increase in workers who “usually or always” wore a broad-brimmed hat, a 20% increase in the use of natural shade, a 19% increase in workers wearing long-sleeved collared shirts, and a 16% increase in workers wearing long trousers.

Lysine residues of IGF-I are substrates for transglutaminases and modulate downstream IGF-I signalling

Numerous studies have reported associations between IGF-I and other extra cellular matrix (ECM) proteins, including fibronectin (FN), integrins, IGF-binding proteins (IGFBPs) and through IGFBPs, with vitronectin (VN). Nevertheless, the precise nature and mechanisms of these interactions are still being characterised. In this paper, we discuss transglutaminases (TGases) as a constituent of the ECM and provide evidence for the first time that IGF-I is a lysine (K)-donor substrate to TGases. When IGF-I was incubated with an alpha-2 plasmin inhibitor-derived Q peptide in the presence of tissue transglutaminase (TG2), an IGF-I:Q peptide cross-linked species was detected using Western immunoblotting and confirmed by mass spectrometry. Similar findings were observed in the presence of Factor XIIIa (FXIIIa) TGase. To identify the precise location of this K-donor TGase site/s on IGF-I, all the three IGF-I K-sites, individually and collectively (K27, K65 and K68), were substituted to arginine (R) using site-directed mutagenesis. Incubation of these K→R IGF-I analogues with Q peptide in the presence of TG2 or FXIIIa resulted in the absence of cross-linking in IGF-I analogues bearing arginine substitution at site 68. This established that K68 within the IGF-I D-domain was the principal K-donor site to TGases. We further annotated the functional significance of these K→R IGF-I analogues on IGF-I mediated actions. IGF-I analogues with K→R substitution within the D-domain at K65 and K68 hindered migration of MCF-7 breast carcinoma cells and correspondingly reduced PI3-K/AKT activation. Therefore, this study also provides first insights into a possible functional role of the previously uncharacterised IGF-I D-domain.

Molecular cytogenetic analysis of basal cell carcinoma DNA using comparative genomic hybridization

In an attempt to define genomic copy number changes associated with the development of basal cell carcinoma, we investigated 15 sporadic tumors by comparative genomic hybridization. With the incorporation of tissue microdissection and degenerate oligonucleotide primed-polymerase chain reaction we were able to isolate, and then universally amplify, DNA from the tumor type. This combined approach allows the investigation of chromosomal imbalances within a histologically distinct region of tissue. Using comparative genomic hybridization we have observed novel and recurrent chromosomal gains at 6p (47%), 6q (20%), 9p (20%), 7 (13%), and X (13%). In addition comparative genomic hybridization revealed regional loss on 9q in 33% of tested tumors encompassing 9q22.3 to which the putative tumor suppressor gene, Patched, has been mapped. The deletion of Patched has been indicated in the development of hereditary and sporadic basal cell carcinomas. The identification of these recurrent genetic aberrations suggests that basal cell carcinomas may not be as genetically stable as previously thought. Further investigation of these regions may lead to the identification of other genes responsible for basal cell carcinoma formation.