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Analytical Epidemiological Studies of Spotty Liver Disease in Australian Cage-free Laying Hens
No full textSpotty liver disease (SLD) is an infectious disease mainly reported in free-range laying hens, causing
significant mortality and production losses. Since the isolation and identification of Campylobacter
hepaticus and C. bilis, the causative agents of Spotty liver disease (SLD), significant advancement
has been made in characterising the pathogen and understanding the transmission and spread of the
disease. Yet, an in-depth understanding of SLD epidemiology is still lacking.
An opinion survery (Chapter 2) was first used to scope the industry experience and hypotheses on
SLD risk factors. This was followed by the preliminary cross-sectional study (Chapter 3) in cage-free
laying flocks (n=24) across different states of Australia. It was found that the presence of a scratch
area inside the poultry house is a risk factor for SLD (P = 0.003). Notably, despite the absence of a
scratch area, almost half of the laying flocks in fully slatted houses (barn and free-range) in the preliminary study developed clinical SLD. This highlighted that other putative risk factors could
precipitate SLD occurrence.
The second survey searched for further risk factors that may exist in houses with a floor fully covered
by slats (n=49) (Chapter 4). The study indicated that layer houses with naturally ventilated
environmental control systems are a key determinant of the risk for SLD (P = 0.002). Further analysis
showed that a higher nest density (birds per m2 nest space) has a stronger risk of causing SLD (P =
0.015).
A third field study was conducted to study putative risk factors for SLD in flocks (n=48) from sheds
with a scratch area (Chapters 5 and 6). The absence of cool cells, i.e. less efficient shed cooling, was
thought to be a statistically important risk factor for SLD (P = 0.028).
To the author’s knowledge, this thesis is the first to report on risk factors, more importantly key
determinants, of SLD based on a series of descriptive and analytical epidemiological studies
Orbit data of q-difference Painlevé one over finite fields
No full textThis item includes data on orbit lengths of q-difference Painlevé one over finite fields as well as code used to generate and analyse it.Software: Magma and Mathematic
Identity and Investment of Chinese Heritage Language Learners in Australian Higher Education
No full textThe growing number of Chinese heritage language learners (CHLLs) in Chinese language classrooms at North American and Australian universities has compelled some institutions to offer special classes for them that generally aim to accelerate their literacy development. However, despite these custom efforts, high rates of student attrition pose significant challenges for educators, underscoring the need for a more holistic understanding of the learning experiences and commitments of CHLLs. With this improved understanding, better strategies can be formulated that are tailored to support student long-term enrolment and language development.
Limited sociocultural research has explored the identities and lived experiences of CHLLs in specialised classes. This classroom-based qualitative study remedies this by using an identity approach to language learning. It investigates the identities of CHLLs and their investment in Chinese language learning, and focuses on the interplay between their heritage, capital, and ideologies within an Australian university context. Using a multi-method qualitative design, data are collected through classroom observations, interviews, descriptive questionnaires, student journals, and various documents and artefacts. Seventeen CHLLs and their teacher participated in this research.
Data reveal that CHLLs engage in heterogeneous processes of identity formation, with their investment in Chinese language not necessarily related to strengthening their heritage connections. Instead, CHLLs seek varied forms of capital linked to their multifaceted identities. Furthermore, their dynamic investment in Chinese learning emerges from the ongoing negotiation of identities, capital, and ideologies throughout their learning trajectories.
Results and their interpretation contribute to a deeper knowledge of CHLLs in Australian higher education and improve understanding of heritage language acquisition. Additionally, empirical evidence is provided to verify and extend Norton and Darvin’s theories on language learning, and practical recommendations for curriculum design and pedagogy are proposed. These suggestions aim to create more inclusive, equitable, and engaging learning environments for CHLLs
Intra-Professional Cultural Competence: Exploring a Strategy to Support Internationally Qualified Nurses and Australia’s Culturally and Linguistically Diverse Nursing Workforce
No full textThis four-part thesis examined the experiences of internationally qualified nurses (IQNs) and culturally and linguistically diverse (CALD) nurses in Australia through exploratory descriptive research. It aimed to determine the barriers and facilitators to the professional integration of IQNs in Australia; identify the cultural and linguistic characteristics of the Australian nursing workforce; ascertain how regulators address the barriers and facilitators to IQN integration; explore how educational and regulatory experts view the elements of Intra-professional Cultural Competence (IPCC) in Australia; and analyse the experiences of the elements of IPCC in one nursing school.
Four studies were undertaken: Study One -a systematic review- identified challenges to IQN professional integration. Study Two -a workforce data analysis- identified that when IQNs and overseas-born locally qualified nurses are included, CALD nurses may represent 43% of the Australian nursing workforce. Study Two developed the concept of IPCC to explore the intra-professional applicability of cultural competence. IPCC was defined by four elements: mutual collaboration and professional relationships; prevention of racism and discrimination (R&D) and bullying and harassment (B&H); respecting values, attitudes and beliefs of individuals from different cultures; and responding appropriately to cross-cultural interactions with colleagues. These elements were further examined in Studies Three and Four.
Study Three -an examination of nursing regulatory documents- demonstrated the presence of IPCC elements in these documents. Study Four -the interviews with educational and regulatory experts, academics and clinical educators- confirmed that, while IPCC elements were recognised in both regulatory documents and educational practices, R&D and B&H also coexist. The thesis concludes with a discussion of recommendations relevant to the integration of IPCC and implications for future research
Facilitators and barriers to the clinical trial recruitment of older people: A qualitative study
No full textOlder people are consistently under-represented or excluded from clinical trials investigating treatments for conditions that commonly affect them. The main objective of this thesis is to explore how accepted, socially constructed ‘truths’ about ageing and older people inform key stakeholders’ perspectives and subsequently affect clinical trial recruitment practices. Key stakeholders include researchers, ethics committee members and older people with and without trial experience. The thesis also reviews Australian and international clinical trial guidance relating to the inclusion of older participants and analyses Australian clinical trial protocols for criteria that may exclude older participants. Findings revealed that many stakeholders had absorbed common age stereotypes which influenced their assumptions and expectations about older people as clinical trial participants. There was a level of disinterest and lack of engagement with the issue of under-representation among some general researchers and ethics committee members. Researchers who work closely with older people were aware of and largely challenged negative assumptions and beliefs through recruitment approaches built on inclusivity and purposeful, targeted actions. Most older people constructed an identity that was not defined by age or age stereotypes. They wanted to contribute to the greater good and advance medical knowledge through trial participation, with many speaking against the homogenisation of older people and the inequitable exclusion of older trial participants. Analysis of clinical trial guidelines revealed that Australian guidance is out of step with similar countries in that they do not specifically address the issue of older people’s under-representation in clinical trials. Analysis of registered Australian trial protocols showed the use of upper age limits and exclusion criteria that are likely to disproportionately exclude older people from trial participation
Safety, Usability, and Acceptability of Microarray Patches for Vaccination
No full textBackground: Microarray patches (MAPs) are a needle-free vaccine delivery device that targets the epidermis and upper dermis. This thesis aimed to investigate the safety, usability, and acceptability of MAPs for vaccination among older adults, the general public, and healthcare professionals (HCPs).
Methods: A review was conducted to assess the immunogenicity, safety, usability, and acceptability of MAPs. Semi-structured interviews with older adults explored MAP benefits and challenges. The MAP for Vaccination Scale (MAPVac) was developed through literature reviews, expert assessments, and interviews to evaluate perceptions of MAP safety, usability, and acceptability. Surveys were administered in Australia, Canada, New Zealand, and the United Kingdom. Descriptive statistics were used for survey analysis, and thematic analysis was applied to interview data.
Results: Clinical trials with influenza and Japanese encephalitis vaccines demonstrated that MAPs were immunogenic, with mild erythema as the only reported side effect. Pain scores were lower for MAPs compared to needle and syringe (N&S). In interviews with older adults (n=44), MAPs were viewed as convenient due to their ease of use, with potential to reduce healthcare burden. Concerns included the safety of unsupervised use and immunisation recording accuracy. The MAPVac scale showed high internal consistency (Cronbach’s alpha=0.90) and repeatability. Survey results from 403 members of the general public and 184 HCPs indicated that MAPs were considered safe, usable, and acceptable. Thematic analysis of interviews (n=27) revealed that MAPs were beneficial for individuals with needle-related anxiety, and HCPs showed interest in using MAPs in practice.
Conclusion: MAPs were generally found to be safe, effective, and user-friendly alternatives to N&S. The availability and accessibility of vaccine MAPs could enhance vaccination rates among key populations and those in low-resource settings
Two sides of drug discovery – characterizing a challenging target and exploring the potential of macrocyclic peptides.
No full textTarget-driven drug discovery is a complex and multidisciplinary process that requires significant effort. It starts with identifying and validating a therapeutically relevant target. Once validated, producing this target in tractable form allows for detailed molecular structure analysis. This structural understanding is highly beneficial during subsequent drug discovery process, which involves screening for molecules that interact with the target while meeting certain therapeutic criteria. These molecules can be identified using a variety of screening techniques. Importantly, close collaboration between target structural characterisation and molecule screening techniques improves the overall
efficiency of the drug discovery process. This thesis explores both key aspects: First, it will explore the discovery of macrocyclic peptide molecules by mRNA display that interact with targets while possessing therapeutically desirable properties. Second, it will explore efforts directed towards production and structural characterisation of a therapeutic target - the P2X7 receptor
Leveraging Relative Position for Trajectory Learning in Text-based Games
No full textText-based games (TBG) are complex environments that allow users or computer agents to make textual interactions and achieve game goals. The text-based gameplay experiences are comparable to smart computing agent task episodes, which are understanding user text input and achieving a target to get user satisfaction. Designing text-based game agents that autonomously learn from the games and reach the game goals is challenging. In order to understand and propose our way to tackle this challenge, we first need to systematically classify and analyze text-based game agent-related methods. Based on the encoder analysis and observations, we propose a new model to improve the text-based game agent's trajectory learning capability, allowing the agent to learn from its gameplay experience and improve performance.
In this thesis, we first review the related literature of text-based games and analyze associated methods. We implemented a standardized agent and performed ablation tests on selected encoder models, which allowed us to choose the best-performing encoder architecture. Next, with a Transformer-based model chosen as our base model, we propose a model that uses a GPT encoder to replace the widely adopted LSTM trajectory encoder to improve text-based game agent trajectory learning capability. To capture the state relationship of the text-based game environment, we extend the relative positional embedding used in traditional NLP tasks into state trajectory learning under the Reinforcement Learning framework. We analyze the critical differences between relative positional embedding used in traditional NLP tasks and reinforcement learning state observation trajectory learning. We propose our exploration trajectory embedding, which is the first relative positional embedding used in this field. Our experiment shows that our model, together with the newly introduced relative positional embedding, brings substantial improvement to text-based game trajectory learning
Advanced electrochemical oxidative leaching of chalcopyrite
No full textThis thesis presents a sustainable and highly efficient method for extracting copper from chalcopyrite, the most common copper ore. Addressing the soaring global demand for copper, the research introduces a novel electrochemical oxidative leaching process that overcomes the limitations of traditional methods.
The core of the technology involves generating powerful reactive oxygen species (ROS) in an acidic solution to dissolve the ore. The study highlights several key findings: first, the use of boron-doped diamond (BDD) electrodes achieves a copper dissolution rate 13 times faster than conventional leaching. The addition of ultrasound further accelerates this process.
Second, a new CeO
2
-PbO
2
/BTNA anode was developed, showing superior performance with over 90% copper recovery and a faster reaction rate. Finally, the research explores UV-assisted electrooxidation, which significantly boosts efficiency by creating a more homogeneous distribution of ROS. This process increased the leaching rate by 104%.
Overall, the thesis provides a strong proof of concept for a cleaner, more efficient copper extraction method. Its findings offer a solid scientific basis for future commercialization, minimizing environmental impact while addressing the critical need for sustainable mineral processing
Quick—Nobody’s Looking: Sidestepping Structures of Power in Contemporary Art through Wry Humour and Absurdist Institutional Critique
No full textHow might a contemporary artist trouble systems that prize compliance and quietly sideline dissent? Can criticality in contemporary art be sustained when collection and dissemination are reliant on platforms invented to favour aesthetic experience? This thesis examines specific aspects of the contemporary art world’s inner workings as I have encountered them—through both participation and critique. It presents a synthesis of social, institutional, and self-critique.
The research begins with Marcel Duchamp’s 1963 retrospective at the Pasadena Museum of Art and examines his influence on first-generation Californian conceptual artists. It also explores connections and contrasts with historical and contemporary conceptual artists in New York, Europe, and Australia.
The project surveys subversive approaches employed by seminal artists to bypass conventional museum models, social networks, art pedagogy, and tacit rules sanctioned by cultural gatekeepers. Building upon institutional critique from the 1970s and 1990s, it advocates for new methods of art critique that navigate institutional entanglements.
Research was conducted at international libraries, archives, and through witnessing actions by key artists. Hybrid creative-critical writing was employed to collapse the conventional dichotomy of artworks and the written component. The creative works of this thesis range from text-based finger paintings to performances with hired actors. Through a cocktail of absurd and wry humour, they confront the status quo of contemporary art and advance new frames of knowledge