Investigation of megavoltage beams and detectors for electronic portal imaging

Accuracy of dose delivery in external beam radiotherapy is usually verified with electronic portal imaging (EPI) in which the treatment beam is used to check the positioning of the patient. However the resulting megavoltage x-ray images suffer from poor quality. The image quality can be improved by developing a special operating mode in the linear accelerator. The existing treatment beam is modified such that it produces enough low-energy photons for imaging. In this work the problem of optimizing the beam/detector combination to achieve optimal electronic portal image quality is addressed. The linac used for this study was modified to produce two experimental photon beams. These beams, named Al6 and Al10, were non-flat and were produced by 4MeV electrons hitting aluminum targets, 6 and 10mm thick respectively. The images produced by a conventional EPI system (6MV treatment beam and camera-based EPID with a Cu plate & Gd2O2S screen ) were compared with the images produced by the experimental beams and various screens with the same camera). The contrast of 0.8cm bone equivalent material in 5 cm water increased from 1.5% for the conventional system to 11% for the combination of Al6 beam with a 200mg/cm2 Gd2O2S screen. The signal-to-noise ratio calculated for 1cGy flood field images increased by about a factor of two for the same EPI systems. The spatial resolution of the two imaging systems was comparable. This work demonstrates that significant improvements in portal image contrast can be obtained by simultaneous optimization of the linac spectrum and EPI detector.

Digital social signal processing - theorectical underpinning and research agenda

Organizations make increasingly use of social media in order to compete for customer awareness and improve the quality of their goods and services. Multiple techniques of social media analysis are already in use. Nevertheless, theoretical underpinnings and a sound research agenda are still unavailable in this field at the present time. In order to contribute to setting up such an agenda, we introduce digital social signal processing (DSSP) as a new research stream in IS that requires multi-facetted investigations. Our DSSP concept is founded upon a set of four sequential activities: sensing digital social signals that are emitted by individuals on social media; decoding online data of social media in order to reconstruct digital social signals; matching the signals with consumers’ life events; and configuring individualized goods and service offerings tailored to the individual needs of customers. We further contribute to tying loose ends of different research areas together, in order to frame DSSP as a field for further investigation. We conclude with developing a research agenda.

Investigation of ultra trace detection in functionalised-surface enhanced Raman spectroscopy (SERS)

We have developed an explanation for ultra trace detection found when using Au/Ag SERS nanoparticles linked to biochemical affinity tags, e.g. antibodies. The nanoparticle structure is not as usually assumed and the aggregated nanoparticles constitute hot spots that are indispensable for these very low levels of analyte detection, even more so when using a direct detection method.

Collaborative learning and critical thinking in technology-enhanced environments : an instructional design framework

The nature and characteristics of how learners learn today are changing. As technology use in learning and teaching continues to grow, its integration to facilitate deep learning and critical thinking becomes a primary consideration. The implications for learner use, implementation strategies, design of integration frameworks and evaluation of their effectiveness in learning environments cannot be overlooked. This study specifically looked at the impact that technology-enhanced learning environments have on different learners’ critical thinking in relation to eductive ability, technological self-efficacy, and approaches to learning and motivation in collaborative groups. These were explored within an instructional design framework called CoLeCTTE (collaborative learning and critical thinking in technology-enhanced environments) which was proposed, revised and used across three cases. The field of investigation was restricted to three key questions: 1) Do learner skill bases (learning approach and eductive ability) influence critical thinking within the proposed CoLeCTTE framework? If so, how?; 2) Do learning technologies influence the facilitation of deep learning and critical thinking within the proposed CoLeCTTE framework? If so, how?; and 3) How might learning be designed to facilitate the acquisition of deep learning and critical thinking within a technology-enabled collaborative environment? The rationale, assumptions and method of research for using a mixed method and naturalistic case study approach are discussed; and three cases are explored and analysed. The study was conducted at the tertiary level (undergraduate and postgraduate) where participants were engaged in critical technical discourse within their own disciplines. Group behaviour was observed and coded, attributes or skill bases were measured, and participants interviewed to acquire deeper insights into their experiences. A progressive case study approach was used, allowing case investigation to be implemented in a "ladder-like" manner. Cases 1 and 2 used the proposed CoLeCTTE framework with more in-depth analysis conducted for Case 2 resulting in a revision of the CoLeCTTE framework. Case 3 used the revised CoLeCTTE framework and in-depth analysis was conducted. The findings led to the final version of the framework. In Cases 1, 2 and 3, content analysis of group work was conducted to determine critical thinking performance. Thus, the researcher used three small groups where learner skill bases of eductive ability, technological self-efficacy, and approaches to learning and motivation were measured. Cases 2 and 3 participants were interviewed and observations provided more in-depth analysis. The main outcome of this study is analysis of the nature of critical thinking within collaborative groups and technology-enhanced environments positioned in a theoretical instructional design framework called CoLeCTTE. The findings of the study revealed the importance of the Achieving Motive dimension of a student’s learning approach and how direct intervention and strategies can positively influence critical thinking performance. The findings also identified factors that can adversely affect critical thinking performance and include poor learning skills, frustration, stress and poor self-confidence, prioritisations over learning; and inadequate appropriation of group role and tasks. These findings are set out as instructional design guidelines for the judicious integration of learning technologies into learning and teaching practice for higher education that will support deep learning and critical thinking in collaborative groups. These guidelines are presented in two key areas: technology and tools; and activity design, monitoring, control and feedback.

An investigation into painting's transformation and regeneration through post-photographic intervention in the digital archive

This PhD practice-led research inquiry sets out to examine and describe how the fluid interactions between memory and time can be rendered via the remediation of my painting and the construction of a digital image archive. My abstract digital art and handcrafted practice is informed by Deleuze and Guattari’s rhizomics of becoming. I aim to show that the technological mobility of my creative strategies produce new conditions of artistic possibility through the mobile principles of rhizomic interconnection, multiplicity and diversity. Subsequently through the ongoing modification of past painting I map how emergent forms and ideas open up new and incisive engagements with the experience of a ‘continual present’. The deployment of new media and cross media processes in my art also deterritorialises the modernist notion of painting as a static and two dimensional spatial object. Instead, it shows painting in a postmodern field of dynamic and transformative intermediality through digital formats of still and moving images that re-imagines the relationship between memory, time and creative practice.

A retrospective cohort investigation of active range of motion within one week of open reduction and internal fixation of distal radius fractures

Distal radius fractures stabilized by open reduction internal fixation (ORIF) have become increasingly common. There is currently no consensus on the optimal time to commence range of motion (ROM) exercises post-ORIF. A retrospective cohort review was conducted over a five-year period to compare wrist and forearm range of motion outcomes and number of therapy sessions between patients who commenced active ROM exercises within the first seven days and from day eight onward following ORIF of distal radius fractures. One hundred and twenty-one patient cases were identified. Clinical data, active ROM at initial and discharge therapy assessments, fracture type, surgical approaches, and number of therapy sessions attended were recorded. One hundred and seven (88.4%) cases had complete datasets. The early active ROM group (n = 37) commenced ROM a mean (SD) of 4.27 (1.8) days post-ORIF. The comparator group (n = 70) commenced ROM exercises 24.3 (13.6) days post-ORIF. No significant differences were identified between groups in ROM at initial or discharge assessments, or therapy sessions attended. The results from this study indicate that patients who commenced active ROM exercises an average of 24 days after surgery achieved comparable ROM outcomes with similar number of therapy sessions to those who commenced ROM exercises within the first week.

Investigation of the chemical and physical basis of oxidative stress generated by particulate matter using the profluorescent probe technique

Following the growing need for adoption of alternative fuels, this project aimed at getting more information on the oxidative potential of biodiesel particulate matter. Within this scope, the physical and chemical characteristics of biodiesel PM were analysed which lead to identification of reactive organic fractions. An in-house developed proflurescent nitroxide probe was used. This project further developed in-depth understanding of the chemical mechanisms following the detection of the oxidative potential of PM. This knowledge made a significant contribution to our understanding of processes behind negative health effects of pollution and enabled us to further develop new techniques to monitor it.

Spectroscopic investigation of the polymerisation of pyrrole and thiophene within zeolite channels

The reaction of pyrrole and thiophene monomers with copper- or nickel-exchanged mordenite has been investigated using X-ray photoelectron (XPS) and photoacoustic infrared (PAIRS) spectroscopies. Because of the differing oxidising powers of the cations studied, polymerisation occurred only with copper-exchanged mordenite. PAIRS and XPS data indicated that both polypyrrole and polythiophene were partially oxidised when synthesised within the zeolite structure. IR spectra of polythiophene and polythiophene and polypyrrole showed intense bands typical of ring vibrations which could couple to the large dipole change induced by charges moving along the polythiophene chain. In addition it was noted that only vibrations typical of oxidised polymer structures were recorded, suggesting that the charge carrier was located within these segments. Furthermore, N 1s spectra contained a high binding energy peak at 402.5 eV which was attributed to a positively charged nitrogen species, in agreement with IR data. Significantly, C 1s spectra confirmed that molecular wires were formed within the confines of the zeolite lattice. Depth-profiling experiments suggested that polypyrrole was distributed throughout the entire zeolite host. By contrast, polythiophene may have been restricted to the uppermost zeolite channels owing to the ability of sulfur species to bond to CuI sites [produced by reduction of copper(II) ions during the polymerisation process], thus obstructing movement along the channels.

An investigation of factors influencing diabetes self-management among adults with type 2 diabetes in Vietnam

Background: In diabetes care, health care professionals need to provide support for their patients. In order to provide good diabetes self-management support for adults with type 2 diabetes in Vietnam, it is important that health care professionals in Vietnam understand the factors influencing diabetes self-management among these people. However, knowledge about factors influencing diabetes self-management among adults with type 2 diabetes in Vietnam is limited. Objectives: This study aimed to investigate factors influencing diabetes self-management among adults with type 2 diabetes in Vietnam. Methodology: A cross-sectional survey with convenience sampling was conducted on 198 adults with type 2 diabetes in VietnamData collection was administeted via interview. Descriptive statistics, simple correlation statistics and structural equation modelling statistics were used for data analysis. Results: Adults with type 2 diabetes in Vietnam had limited diabetes knowledge (Median = 6.0). The majority of the study participants (72.7%) believed that performing diabetes self-management activities was very important or extremely important for controlling their blood glucose levels and for preventing complications from diabetes; about half usually received support from their family and friends’ (48.5%), and around two thirds rarely received support from their health care providers (68.2%). Many of the participants (41.4%) had limited confidence to perform diabetes management activities. The practices of diabetes self-management were limited among the study population (Mean = 96.7, SD = 19.4). Diabetes knowledge (β = 0.17, p < .001), belief in treatment effectiveness (β = 0.13, p < .01), family and friends’ support (β = 0.13, p < .001), health care providers’ support (β = 0.27, p < .001) and diabetes management self-efficacy (β = 0.43, p < .001) directly influenced their diabetes self-management. Diabetes knowledge, and family and friends’ support also indirectly influenced diabetes self-management among these people through their belief in treatment effectiveness and their diabetes management self-efficacy (p < .05). Conclusion: Findings in this study indicated that health care professionals should provide diabetes self-management support for adults with type 2 diabetes in Vietnam in the future. The adapted theory-based model of factors influencing diabetes self-management among adults with type 2 diabetes in Vietnam found in this study could be a useful framework to develop this supporting program.

An investigation of the lived experiences of Intensive Care Paramedics

Intensive Care Paramedics (ICPs) attend to only the most clinically challenging of emergency medical cases, often working in a chaotic and frenetic atmosphere. They are regularly exposed to human tragedy and with that, the potential to experience traumatic events is not uncommon. There is very little known about the well-being of ICPs; how they cope with the demands of their role, or about their mental health in general. Nineteen experienced ICPs (4 female, 15 male) participated in a semi-structured interview. Themes were extracted from the data using an Interpretive Phenomenological Analysis approach. All participants discussed a work-related event they attended that traumatized them, usually experienced in the earlier parts of their career. Some spoke of an immediate overwhelming of their capacity to cope and others of a gradual onset of traumatic stress when reflecting on the event at a later time. More than half of the participants described events that involved children as the most difficult. Data revealed four superordinate themes: Social Support, Cognitive Coping, Proactive Coping, and Long Term Effects. Each superordinate theme comprised a number of constituent themes which are presented in this paper and exemplified with participant quotes. Although ongoing distress was described by some participants, all of the ICPs interviewed discussed positive aspects of their job; things that made the role worthwhile and fulfilling. This research highlights the important factors involved in coping with, and growing from, the extraordinary events that ICPs face. Results have implications for employing organizations and staff support services as well as for paramedics more broadly as they learn to cope with events inherent in their career. Findings indicate that positive adaptation and personal growth as a result of exposure to extremely high levels of potentially traumatic experiences is not only possible, but highly probable.

Information skills coursework for postgraduate students : investigation and response at the Queensland University of Technology

In response to current developments In the tertiary education sector, the Queensland University of Technology Library has mounted an Intensive course - Advanced Information Retrieval Skills - for higher degree students. In determining need for such a course, a survey of postgraduate students and their supervisors was conducted. Results of this survey are discussed and details of the four credit point subjects are outlined.

Responding to a transformative stressor : climate change and the institutional governance of Australian cities

This paper understands climate change as a transformative stressor that will prompt responses from institutional governance frameworks in Australian cities. A transformative stressor is characterised as a chronic large-scale phenomenon which triggers a process of institutional change whereby institutions seek to reorientate their activities to better manage the social, economic and environmental impacts created by the transformative dynamic. It is posited that institutional change will be required as Australian metropolitan institutional governance frameworks seek to manage climate change effects in urban environments. It is argued that improved operationalisation of adaptation is required as part of a comprehensive urban response to the transformative stresses climate change and its effects are predicted to create in Australian cities. The operationalisation of adaptation refers to adaptation becoming incorporated, codified and implemented as a central principle of metro-regional planning governance. This paper has three key purposes. First, it examines theoretical and conceptual understandings of the role of transformative stressors in compelling institutional change within urban settings. Second, it establishes a conceptual approach that understands climate change as a transformative stressor requiring institutional change within the metropolitan planning frameworks of Australia's cities. Third, it offers early results and conclusions from an empirical investigation into the current prospects for operationalisation of climate adaptation in planning programs within Southeast Queensland (SEQ) via changes to institutional governance. A significant emerging conclusion is that early climate stresses appear not to be leading to episodic institutional change in the metropolitan planning frameworks of SEQ.

Information literacy : a theoretical framework for higher education

Information literacy has been a significant issue in the library community for many years. It is now being recognised as an important issue by the higher education community. This theoretical framework draws together important elements of the information literacy agenda specifically for tertiary educators and administrators. The frame-work examines three areas of primary concern: the possible outcomes of information literacy education (through outlining the characteristics of information literate people); the nature of information literacy education; and the potential role of stake-holders (including information services, faculty, staff developers and learning counsellors) in helping staff and students to be information literate. This theoretical framework forms part of the Griffith University Information Literacy Blueprint. The Blueprint was designed between June and August of 1994. The project, a quality initiative of the Division of Information Services, was led by Janice Rickards, University Librarian.

Producing and maintaining professional identities in early childhood

This study is an inquiry into early childhood teacher professional identities. In Australia, workforce reforms in early childhood include major shifts in qualification requirements that call for a university four-year degree-qualified teacher to be employed in child care. This marks a shift in the early years workforce, where previously there was no such requirement. At the same time as these reforms to quality measures are being implemented, and requiring a substantive up skilling of the workforce, there is a growing body of evidence through recent studies that suggests these same four-year degree-qualified early childhood teachers have an aversion to working in child care. Their preferred employment option is to work in the early years of more formal schooling, not in before-school contexts. This collision of agendas warrants investigation. This inquiry is designed to investigate the site at which advocacy for higher qualification requirements meets early childhood teachers who are reluctant to choose child care as a possible career pathway. The key research question for this study is: How are early childhood teachers’ professional identities currently produced? The work of this thesis is to problematise the early childhood teacher in child care through a particular method of discourse analysis. There are two sets of data. The first was a key early childhood political document that read as a "moment of arising" (Foucault, 1984a, p. 83). It is a political document which was selected for its current influence on the early childhood field, and in particular, workforce reforms that call for four-year degree-qualified teachers to work in before-school contexts, including child care. The second data set was generated through four focus group discussions conducted with preservice early childhood teachers. The document and transcripts of the focus groups were both analysed as text, as conceptualised by Foucault (1981). Foucault’s work spans a number of years and a range of philosophical matters. This thesis draws particularly on Foucault’s writings on discourse, power/knowledge, regimes of truth and resistance. In order to consider the production of early childhood teachers’ professional identities, the study is also informed by identity theorists, who have worked on gender, performativity and investment (Davies, 2004/2006; McNay, 1992; Osgood, 2012; Walkerdine, 1990; Weedon, 1997). The ways in which discourses intersect, compete and collide produce the subject (Foucault, 1981) and, in the case of this inquiry, there are a number of competing discourses at play, which produce the early childhood teacher. These particular theories turn particular lenses on the question of professional identities in early childhood, and such a study calls for the application of particular methodologies. Discourse analysis was used as the methodological framework, and the analysis was informed by Foucauldian concepts of discourse. While Foucault did not prescribe a form of discourse analysis as a method, his writings nonetheless provide a valuable framework for illuminating discursive practices and, in turn, how people are affected, through the shifts and distribution of power (Foucault, 1980a). The treatment used with both data sets involved redescription. For the policy document, a technique for reading document-as-text applied a genealogical approach (Foucault, 1984a). For the focus groups, the process of redescription (Rorty, 1989) involved reading talk-as-text. As a method, redescription involves describing "lots and lots of things in new ways until you have created a pattern of linguistic behaviour which will tempt the new generation to adopt it" (Rorty, 1989, p. 9). The development and application of categories (Davies, 2004/2006) built on a poststructuralist theoretical framework and the literature review informed the data analysis method of discourse analysis. Irony provided a rhetorical and playful tool (Haraway, 1991; Rorty, 1989), to look to how seemingly opposing discourses are held together. This opens a space to collapse binary thinking and consider seemingly contradictory terms in a way in which both terms are possible and both are true. Irony resists the choice of one or the other being right, and holds the opposites together in tension. The thesis concludes with proposals for new, ironic categories, which work to bring together seemingly opposing terms, located at sites in the field of early childhood where discourses compete, collide and intersect to produce and maintain early childhood teacher professional identities. The process of mapping these discourses goes some way to investigating the complexities about identities and career choices of early childhood teachers. The category of "the cost of loving" captures the collision between care/love, inherent in child care, and new discourses of investment/economics. Investment/economics has not completely replaced care/love, and these apparent opposites were not read as a binary because both are necessary and both are true (Haraway, 1991). They are held together in tension to produce early childhood teacher professional identities. The policy document under scrutiny was New Directions, released in 2007 by the then opposition ALP leader, Kevin Rudd. The claim was made strongly that the "economic prosperity" of Australia relies on investment in early childhood. The arguments to invest are compelling and the neuroscience/brain research/child development together with economic/investment discourses demand that early childhood is funding is increased. The intersection of these discourses produces professional identities of early childhood teachers as a necessary part of the country’s economy, and thus, worthy of high status. The child care sector and work in child care settings are necessary, with children and the early childhood teacher playing key roles in the economy of the nation. Through New Directions it becomes sayable (Foucault, 1972/1989) that the work the early childhood teacher performs is legitimated and valued. The children are produced as "economic units". A focus on what children are able to contribute to the future economy of the nation re-positions children and produces these "smart productive citizens", making future economic contribution. The early childhood teacher is produced through this image of a child and "the cost of loving" is emphasised. A number of these categories were produced through the readings of the document-as text and the talk-as-text. Two ironic categories were read in the analysis of the transcripts of the focus group discussions, when treated as talk-as-text data: the early childhood teacher as a "heroic victim"; and the early childhood teacher as a "glorified babysitter". This thesis raises new questions about professional identities in early childhood. These new questions might go some way to prompt re-thinking of some government policy, as well as some aspects of early childhood teacher education course design. The images of children and images of child care provide provocations to consider preservice teacher education course design. In particular, how child care, as one of the early childhood contexts, is located, conceptualised and spoken throughout the course. Consideration by course designers and teacher educators of what discourses are privileged in course content —what discourses are diminished or silenced—would go some way to reconceptualising child care within preservice teacher education and challenging dominant ways of speaking child care, and work in child care. This inquiry into early childhood teachers’ professional identities has gone some way to exploring the complexities around the early childhood teacher in child care. It is anticipated that the significance of this study will thus have immediate applicably and relevance for the Australian early childhood policy landscape. The early childhood field is in a state of rapid change, and this inquiry has examined some of the disconnects between policy and practice. Awareness of the discourses that are in play in the field will continue to allow space for conversations that challenge dominant assumptions about child care, work in child care and ways of being an early childhood teacher in child care.

Investigation of APOE isoforms and the association between APOE E3 and E4 with migraine in the Australian Caucasian population

Migraine is a debilitating neurovascular disease that is associated with pulsating head pain accompanied by nausea, vomiting, photophobia, phonophobia and sometimes visual sensory disturbances. Because of its role in nitric oxide regulation and interleukin release, apolipoprotein E (APOE) has been suggested to play a role in the migraine pathogenesis pathway. This study evaluated the potential role of three APOE variants in an Australian population and the role that they may play in susceptibility to migraine. The study found no significant association between the tested variants and migraine for any of the APOE variants investigated.