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Open Access Theses

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  • ItemOpen Access
    The Use of High Rising Terminals in First- and Second-Generation Mandarin-Background Australians
    (2025) Liu, Chengjin
    This study investigated the use of High Rising Terminals (HRTs)—final rising pitch contours on declarative utterances—among three speaker groups in Australia: first-generation (Gen 1) Mandarin-background Australians, second-generation (Gen 2) Australians from Mandarin-speaking families, and Anglo-Celtic Australians. While HRTs have been widely studied in varieties such as Australian, New Zealand, and American English, their use for ethnolectal purposes remains underexplored. Drawing on spontaneous speech from sociolinguistic interviews, the study examined variation in HRT frequency across ethnic and generational lines, with preliminary analyses of phonetic realisation (rise excursion, rise alignment) and pragmatic function. Results showed that Gen 2 speakers exhibit the highest HRT frequency, followed by Gen 1 speakers, with Anglo speakers showing the lowest usage. A preliminary phonetic and pragmatic analysis revealed that while all groups deploy HRTs for similar discourse functions—such as engagement- and comprehension-checking, turn-holding, stance softening, and epistemic uncertainty—Gen 1 speakers showed greater variation in rise excursion. These findings suggested broad convergence in function but also underlined the role of migration history and identity in shaping suprasegmental patterns. In doing so, the study contributed to the understanding of how prosody, ethnicity, and migrant generation interact in the evolving soundscape of Australian English.
  • ItemOpen Access
    Measuring the Gas-phase Metallicity of AGN-host galaxies with Bayesian Methods
    (2025) Li, Songlin
    Chemical abundances in the interstellar medium record the history of galaxy assembly, and thus investigating abundances in galaxies hosting active galactic nuclei (AGN) is crucial for understanding the role of AGN regulation in the evolution of their host galaxies. In this thesis, we use Bayesian methods to measure gas-phase metallicity in both local AGN and non-AGN hosts with a consistent method that makes it possible to compare both their mean metallicities and their metallicity fluctuation fields. We find that at fixed stellar mass, AGN-host galaxies generally have higher metallicity and smaller metallicity correlation length than non-AGN galaxies. These differences are primarily because AGN hosts have systematically lower star formation rates (SFR) at fixed stellar mass. Our results show that in the local universe, AGN only indirectly influence both the overall mean metallicity and the metallicity fluctuation fields by suppressing star formation activity, and are consistent with a simple model whereby the main effect of an AGN is to reduce accretion of fresh gas onto galaxies, thereby both suppressing the SFR and inhibiting the dilution of metal concentrations by accreting metal-poor gas. In addition, we find that while both SFR and stellar mass are positively correlated with metallicity correlation length, the former is more fundamental, implying that fluctuations in the metallicity distribution within galaxies are driven more by short-term responses to physical processes such as star formation that can change much faster than a Hubble time. We prepare for future observations of AGN hosts at intermediate redshift (z ~ 1-3), where AGN activity is more prevalent and stronger, by evaluating a range of strategies to derive metallicites from the data that will come from the next generation of integral field spectroscopy instruments. The strategies we use to measure metallicity in AGN hosts in the Local Universe will be challenging to apply to these data because they require access to emission lines over a wide wavelength range that will be expensive or impossible to obtain. We show that there are reduced line suites accessible over a narrower wavelength range that will make reasonably good metallicity measurements possible on these instrument over certain intermediate redshift windows. Finally, we propose future works, including improving our Bayesian methods for deriving metalilcities by incorporating additional sources of ionizing radiation, investigating spatially resolved scaling relations, situating our results for the relationship between SFR, metallicity, and AGN activity in the context of galaxy evolution models, and designing strategies for making metallicity fluctuation maps for future IFS observations.
  • ItemOpen Access
    No Harm Done? The Experiences of Women Who Use Drugs In Indonesia
    (2025) Gaddes, Sheilagh
    During the last decade there has been an increase in the number of Indonesian women who identify with using drugs. Women who use drugs are more vulnerable to the range of harms associated with drug use compared with their male counterparts. Despite more than a decade of harm reduction strategies in Indonesia the prevalence of blood-borne viruses (BBV) among people who inject drugs (PWID) are increasing. An estimated one third of people who use drugs in Indonesia are living with the Human Immunodeficiency Virus (HIV). The prevalence of the Hepatitis C virus among people who use drugs in Indonesia is 77 per cent. Also significant is the increase in the incarceration rates of women who use drugs in Indonesia. The increase in the incarceration rates of women charged with drug violations is occurring in the context of Indonesia's 'Drugs Emergency', and the Indonesian Government's commitment to the rehabilitation of the korban narkoba (victims of drugs) by directing people charged with drug use offenses to drug rehabilitation services. In this thesis I explore the experiences of women who use drugs using ethnographic research amongst urban women in two settings in Indonesia across a range of domains of their lives: in the community, in drug rehabilitation services and in prisons. Working with informants who are or have been drug users, some of whom are also peer workers in the harm reduction sector, I demonstrate that women who use drugs are subject to marginalisation and discrimination which poses very real risks to their lives. In many sectors of their lives, Indonesian women who use drugs can access less care and services, and suffer significant directed violence, compared to men who use drugs. Set against the backdrop of Indonesia's 'Drugs Emergency', drawing on policy research as well street-based ethnography, this research provides political and social context to explore the intensification of gendered and class-based forms of structural violence as experienced by women who use drugs in Indonesia.
  • ItemOpen Access
    Automated Modeling Support for Automated Planning
    (2025) Lin, Songtuan
    Automated planning is concerned with the task of finding a sequence of actions to achieve a certain goal. Theoretical investigations have shown that many practical scenarios, e.g., logistics, factories, and Mars rovers, can be modeled using planning frameworks. In spite of that, Automated Planning is not widely deployed in practice, especially outside academia. One major reason for this is the complexity of modeling a practical problem as a planning problem, which necessitates techniques for automated modeling support. In this talk, I would like to address two critical problems in this direction, namely, how to check whether a planning model is constructed correctly and how to repair a flawed planning model. Our approaches for solving these two problems are originated from the common debugging paradigm in programming, i.e., by providing test cases. In our context, a test case is an action sequence that must be a solution (i.e., is feasible and can achieve the goal) if the planning model is flawless. More concretely, we could validate a planning model by checking whether all test cases we provide pass, i.e., whether all provided action sequences are indeed solutions. If some test cases fail, then we know that there are some issues in the planning model, and we call these failed test cases counter-example action sequences (because they are supposed to be solutions but are actually not due to the errors in the model). The repairs can then be made to the planning model which turn all counter-example action sequences into solutions. In my dissertation, I will discuss the computational complexity of verifying whether an action sequence is a solution to a planning problem (i.e., the plan verification problem) and of correcting a planning model by turning counter-example action sequences into solutions. On top of that, I will also introduce some practical approaches we developed for solving those two problems. Lastly, some alternative frameworks for modeling support will also be discussed.
  • ItemOpen Access
    Between Eagle and Dragon: Analyzing Indonesia’s Hedging Behavior under Joko Widodo Administration (2014-2024)
    (2025) Basundoro, Alfin Febrian
    This thesis investigates Indonesia's strategic behavior under President Joko Widodo (Jokowi) amid intensifying U.S.–China competition, using Kuik Cheng-Chwee’s hedging framework and Oriana Skylar Mastro’s alignment measurement. It argues that Indonesia’s foreign policy during Jokowi’s administration (2014-2024) exemplifies a hedging strategy, indicated by strong defense cooperation with the United States and robust economic engagement with China. Through qualitative analysis of key defense and economic policies between 2014 and 2024, this study demonstrates that Indonesia consistently maintains hedging with no significant change in pattern throughout both Jokowi’s terms. Despite increased Indonesia-China economic cooperation and closer maritime and defense ties with the U.S., Indonesia refrains from making binding commitments such as an alliance treaty or falling into major powers’ sphere of influence that would compromise its autonomy. It concludes that Jokowi’s Indonesia has institutionalized hedging as a pragmatic and adaptive foreign policy response, reflecting both the opportunities and constraints of maintaining strategic autonomy in an era of great power rivalry. Ultimately, this research contributes to the empirical findings of Indonesia’s contemporary foreign policy research and highlights Indonesia’s agency in navigating major power competition.
  • ItemOpen Access
    Cellular and molecular characterisation of regeneration in calcareous sponges and soft corals
    (2025) Caglar, Cuneyt
    Regeneration, the ability to replace damaged or lost body parts, is widespread but highly variable across animals, indicating a complex evolutionary history. Studying animals representing early-branching lineages offers unique insights into the fundamental mechanisms and the evolutionary trajectory of this fascinating trait. This thesis investigates the regenerative capacities of soft corals from the genus Xenia and calcareous sponges from the genus Sycon. Cnidarians, which include corals, sea anemone, and jellyfish, are renowned for their remarkable regenerative abilities. Occupying a key phylogenetic position as the sister group to Bilateria, cnidarians offer crucial insights into the evolution of animals. This phylum, encompasses a diverse range of species, generally characterised by overt radial symmetry and a morphologically simple, diploblastic body plan. The soft coral Xenia (Octocorallia) is a prevalent and resilient genus in the shallow waters of Indo-Pacific coral reefs. Xenia possesses a fleshy body embedded with small, platelet-shaped calcium carbonate sclerites providing structural support and protection. The sclerites are produced by calcium secreting cells called scleroblasts. Sponges, representing one of the earliest branching animal lineages, are known for their morphologically simple yet highly efficient body plans, consisting mainly of two layers of epithelial cells. They are capable of whole-body regeneration and reaggregation from dissociated cells, making them ideal models for studying fundamental regenerative processes. The significance of calcareous sponges lies in their phylogenetic position among the oldest extant animal lineages, their directional apical-to-basal axis morphology, and their extensive gene repertoire. Notably, this is the only sponge class to have calcitic skeletal elements, produced by specialised cell types called sclerocytes. Here, I describe the regeneration process in Xenia from small body fragments and identify differential expression of developmental and putative biomineralisation genes. By integrating these findings with available single-cell RNA-Seq data from Xenia and a stony coral species, I have uncovered the transcriptome of Xenia's previously bioinformatically undetected scleroblasts. This discovery sheds light on the evolutionary origin of scleroblasts from secretory cells and reveals an ancestral biomineralisation cassette. Furthermore, I present evidence suggesting that biomineralisation in both soft and stony corals and calcareous sponges evolved independently. In the proposed evolutionary scenario, each lineage inherited an ancestral organic scaffold and subsequently co-opted a biomineralisation toolkit, enabling the deposition of minerals onto the existing organic scaffold. Skeletogenesis in soft corals and calcareous sponges was acquired by mesohyl/mesoglea cells which form small calcitic elements, whereas in stony corals, it occurred within the aboral ectoderm, forming massive aragonitic skeletons. The analysis of the molecular and cellular mechanisms employed by Xenia and Sycon in response to injury and during wound healing revealed the involvement of an ancient animal wound healing pathway, marked by the activation of the immediate early response genes Jun and Fos. This suggests the presence of a conserved animal injury response pathway, which probably originated in the ancestors of all animals. Insights gained in this thesis offer a window into the evolutionary pathways that have shaped the development, regeneration, and biomineralisation processes in animals.
  • ItemOpen Access
    Evaluating plant-pathogen interactions in classical biological control of weeds: Kordyana brasiliensis released against target weed Tradescantia fluminensis in Australia
    (2025) Zeil-Rolfe, Isabel
    Tradescantia fluminensis is a significant environmental weed in Australia invading deeply shaded forests and riparian ecosystems reducing native vegetation species richness and abundance. Biotrophic leaf pathogen, Kordyana brasiliensis has been introduced into Australia and New Zealand as a biocontrol agent for T. fluminensis. Post-release surveys from initial releases have reported successful establishment and variable impacts on T. fluminensis populations, however, impacts on the weed's populations and invaded vegetation communities across broader contexts and temporal gradients remains to be evaluated. This thesis sought to explore aspects of the ecology of K. brasiliensis and T. fluminensis and evaluate short-term outcomes of the biocontrol program in eastern Australia. Chapter 1 examines how different local habitat and regional contexts influence the abundance-impact associations of T. fluminensis in native forests across eastern Australia. We modelled the association of T. fluminensis invasion with native species foliage cover and richness across two different habitat types (remnant vs replanted forests), two vegetation community types (wet sclerophyll vs river oak forests), and two regions (northern vs southern New South Wales). The variation in native species responses amongst different functional growth forms was also modelled. Impacts of T. fluminensis invasion on native species communities was most strongly explained by local site variables. This study highlights the need for site-level weed management plans to consider local community and habitat contexts and functional representation of resident species. Chapter 2 details a series of experiments with K. brasiliensis in controlled environments to investigate whether conidia can cause leaf lesions on T. fluminensis and the effects of temperature and wetness period on basidiospore germination processes (germ-tube formation and elongation, formation of conidia). Inoculations with conidia demonstrated that conidia can cause leaf lesions on T. fluminensis. Basidiospore germination and germ-tube elongation were significantly influenced by the interaction of both temperature and wetness period duration whereas conidia formation was strongly influenced by both factors separately. Chapter 3 details a short-term field experiment where K. brasiliensis was released at sites invaded by T. fluminensis in eastern Australia. Sites were monitored over 30-months to evaluate agent population dynamics, impacts of the agent on T. fluminensis populations, and the subsequent response of invaded vegetation communities. Kordyana brasiliensis rapidly established at all release sites and was strongly influenced by macroclimate variables. On average, T. fluminensis abundance declined significantly after 18-months and was strongly associated with increasing K. brasiliensis disease severity. Declines in T. fluminensis abundance was associated with increases in native species richness. This study demonstrates that K. brasiliensis is a highly damaging agent, however, further long-term monitoring is required to evaluate whether additional management and restoration activities are required. Chapter 4 examines the identity of white leaf lesions collected on two native Australian Commelinaceae hosts during pre- and post-release surveys of K. brasiliensis. The specimens identities were studied using multigene phylogenetic analyses to determine whether K. brasiliensis had extended its known host range, or whether they represented other Kordyana species. Three new species of Kordyana were described based on the phylogenetic analysis, morphology, and host species.
  • ItemOpen Access
    Long Term Laser Frequency Readout for Space Based Interferometry
    (2025) Rees, Emily Rose
    Future space based laser ranging interferometric missions such as the GRACE Continuity (GRACE-C) mission are expected to require absolute laser frequency knowledge. The GRACE Follow-On (GRACE-FO) mission, launched in 2018, included a Laser Ranging Instrument (LRI) as a technology demonstrator. The success of the LRI has led to its selection as the primary instrument for the next mission (GRACE-C), and it will likely also be the primary instrument for other similar future missions. The Gravity Recovery and Climate Experiment (GRACE) missions perform key environmental and climate measurements, particularly monitoring the movement of water around the Earth. The data generated by the GRACE and GRACE-FO missions contribute to approximately one quarter of the fifty-five 'Essential Climate Variables' tracked as part of the Global Climate Observing System (GCOS). The use of a LRI as the primary instrument for future missions requires the development of a new technique to provide absolute laser frequency knowledge, which will allow the science data to be compared over longer timescales of months and years. This thesis presents a proposed technique to achieve this using a dual frequency modulation, and details the experimental demonstration of the technique as well as the risk mitigation activities undertaken. In 2022, the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL) Mission Concept Review recommended this technique for inclusion on the GRACE-C mission, and it now forms part of the mission baseline. The proposed technique adds additional modulation tones to the existing laser stabilisation scheme, which relies on Pound-Drever-Hall (PDH) locking. The additional tones are used to phase modulate the laser light, and can be readout using a similar approach to the PDH technique. By measuring changes to the optical cavity Free Spectral Range (FSR), the readout is sensitive to changes in the optical cavity length, which can be related back to the absolute laser frequency through the relationship dL/L = dv(Laser)/v(Laser) = dv(FSR)/v(FSR). This thesis describes the testing and development of such a dual frequency modulation technique suitable for use on GRACE-C. A proof-of-concept experiment demonstrated the viability of this technique, achieving performance exceeding the expected requirement. A prototype unit was subsequently designed and built in collaboration with CEA Technologies, and has been tested in a flight-like testbed at the ANU and also in the flight-hardware testbed at NASA JPL. This testing identified a number of limitations of the technique, including highlighting the impact of spurious backreflections. The design requirements, interfaces and testing requirements for the prototype unit are all described in detail, along with performance tests undertaken to demonstrate the prototype could achieve performance requirements under expected mission conditions. A high fidelity simulation was developed to model the expected behaviour of the system and has been compared against measured performance, highlighting parameters that must be tightly controlled and where requirements may be relaxed. Finally, an analysis of the limitations of the technique are presented, including a discussion of noise sources and how they compare with typical PDH systems, an assessment of the contributions of spurious backreflections, as well as experimental demonstrations of risk mitigation activities.
  • ItemOpen Access
    Knowledge Graphs and Natural Language: two sides of the same coin
    (2025) Papaluca, Andrea
    In recent years, the fields of Natural Language Processing (NLP) and Knowledge Graphs (KG) have witnessed remarkable advancements, each independently contributing to the enhancement of various AI applications. Knowledge Graphs, structured representations of knowledge, offer a powerful framework for organizing and connecting information, facilitating efficient knowledge retrieval and reasoning. On the other hand, NLP techniques enable machines to understand, generate, and communicate in human language, bridging the gap between human and machine communication. The symbiotic relationship between Knowledge Graphs and Natural Language Processing and Understanding (NLP/NLU) is increasingly recognised as pivotal for advancing AI capabilities. In my thesis in computer science, I delve into the interplay between these two domains, exploring how they complement each other to achieve deeper semantic understanding and more sophisticated reasoning, by proposing and evaluating machine learning methods that integrate them seamlessly. More specifically, the aim is to guide the reader through the boundary connecting NLP to KGs, presenting which routes could be followed to achieve different levels of integration between the two modalities and which degree of improvement has to be expected under each different scenario. The core of the thesis is constituted by three peer-reviewed papers (of which, two were best-paper awarded) that explore different aspects of the integration between Knowledge Graphs and Natural Language. Ranging from the more simple combination of graph and text embeddings through concatenation, to the deeper construction of a multi-modal aligned text-graph space and to the more high level usage of external KGs as reservoirs of commonsense knowledge, the thesis demonstrated how the integration of the two data modalities, and their corresponding encoder models, often enabled better modeling capabilities. This hybrid integration was beneficial in both language related tasks, such as Relation/Triplet Extraction (RE/TE) and Question Answering (QA), and graph associated tasks, such as Link Prediction (LP). Various standard datasets commonly used in literature were adapted and enriched to allow for the joint processing of graph and text information, serving as benchmarks for quantitatively evaluating the improvement over the baseline. The set of tested models included Transformer-based architectures, ranging from their first iterations (e.g., Bidirectional Encoder Representations from Transformers (BERT) and Generative Pre-trained Transformer (GPT)), to the more recent Large Language Models (LLM) (e.g., LLM Meta AI (LLaMA) and Falcon). On the graph side, instead, TransE embeddings as well as declinations of the Graph Convolutional Networks (GCN), like Relational GCN (RGCN) and Compositional GCN (CompGCN), were considered. Each one of these studies presented a different approach to achieve the integration and tested for different facets of reasoning and understanding natural language. However, they all demonstrated how pivotal the interaction of standard NLP models with KGs is for processing natural language. In particular, they evidenced as sometimes (specifically in the LLM case) the integration of an external KG both, leads to larger improvements and constitutes a cheaper approach, compared to, for instance, training and making use of larger, more complex language models. Therefore, the thesis offers a guideline for future research into how the integration of data modalities (and their corresponding encoder models) can enable better modeling capabilities in analysis tasks from answering questions to creating knowledge graphs.
  • ItemOpen Access
    "We are Living in a World not Meant for Us": A Study About Why Girls Are Not Allowed to be Autistic
    (2025) French, Susannah
    In recent years, there has been an increasing amount of evidence that women have been under or misdiagnosed for autism. Some authors would say that this is due to women and girls being more adept at camouflaging their autistic traits (Attwood, 2013; Gould & Ashton-Smith, 2011; Lai, 2017). However, the findings in this thesis reveal that the missed diagnoses go further than this: girls are not allowed to be autistic. That is not to say girls are not autistic or not allowed to be diagnosed with autism, but that girls are not allowed to just be their autistic selves. Women - whether they have been diagnosed or not - try to strategically adapt to a world that is not meant for them while also balancing gendered expectations. Despite one's neurotype, there is an expectation for women and girls to be socially adept, intuitively empathetic, accommodating and nurturing (Eckerd, 2020): traits not typically associated with autism (Baron-Cohen, 2005). This thesis also explores why women often settle for self-diagnosis, what happens when neurotypical and gendered expectations clash, and the specific experiences that come with living with an undiagnosed condition. The aim of this thesis is to explore a small but impactful part of the female experience of autism through three core concepts of conformity, concealment and anticipated stigma. Complimenting these core concepts are the operational notions of biographical illumination, strategic outness, the double empathy problem, and camouflaging/masking. This thesis explores seven case studies about autistic women speaking on their experiences. Throughout each chapter, this thesis analyses the micro-relational interactions and the specific tools they have implemented to live well in a world that is not meant for them. The case studies detail the intricacies of the three core concepts in this thesis in different forms. As a work of sociological inquiry, this thesis's conceptual framework is drawn from Goffman's (1956) dramaturgy, critical autism studies (Davidson & Orsini, 2013; Milton, 2012), queer studies (Orne, 2011; 2013; Pfeffer, 2014) and intersectionality (Crenshaw, 1991; Collins, 2000) . Ultimately, this thesis poses a sustained reconsideration of the female experience of autism along sociological and clinical lines. Ultimately, this thesis contributes a problematisation of the construction of the autism label, the diagnostic process and why girls are not allowed to be autistic.
  • ItemOpen Access
    Genome biology of rust fungi and applications for biosecurity
    (2025) Luo, Zhenyan
    Fungal plant pathogens of the order Pucciniales can cause rust disease on a diverse range of host species, including economically and ecologically important crops and trees. Rust fungi are dikaryotic, maintaining two nuclei per cell throughout most of their life cycle. Urediniospores in the asexual life cycle of rust fungi have high mobility, can easily spread via wind or water, readily infect their host and cause epidemics. The sexual part of the life-cycle provides opportunities for recombination and genetic reassortment generating new virulence combinations. Due to their dikaryotic genome organisation rusts can also exchange nuclei by somatic hybridization asexually, which can also result in the emergence of new virulent strains. Whether two nuclei are compatible are hypothesized to be determined by two permanently heterozygous mating type (MAT) loci: the homeodomain transcription factor (HD) locus and the pheromone receptor (PR) locus. Hence, understanding mating compatibility can help predict possible emergence of new virulent isolates. The genome biology and structure of the MAT locus in rust fungi is unclear since mating compatibility determining loci are often repeat-rich, which makes them difficult to assemble. Now, with high-quality genome assemblies of cereal rust fungi available, this thesis provides detailed insight into the MAT loci of rust fungi. Most rust fungal pathogens such as cereal rust fungi, are highly host-specific, whereas Austropuccinia psidii, the myrtle rust pathogen, has a broad host range and threatens many plants in the Myrtaceae family. The pathogenicity of A. psidii varies among biotypes, with different biotypes displaying different host specificity and aggressiveness. The pandemic biotype has spread globally, including to Australia, causing substantial ecosystem damage. While only the pandemic biotype has been reported in Australia, the introduction of other exotic strains poses a threat of even greater damage to Australian forests. To better understand the genome biology of A. psidii and to develop improved diagnostic tools, a high-quality reference genome is essential. This thesis aims to investigate the genome biology of rust fungi and extend to application in biosecurity via three main objectives: (i) comparative analysis of MAT loci among cereal rust fungi, (ii) generate and investigate haplotype-phased chromosome-scale genome assembly of A. psidii, (iii) develop diagnostic markers to distinguish A. psidii biotypes to improve Australian biosecurity measures. From comparison of MAT loci among four economically important rust species, the research provided insight into the evolutionary history of MAT loci in these species. Understanding mating compatibility can help predict potential emergence of new virulent isolates of these plant pathogens. The high-quality genome assembly of A. psidii served as a fundamental resource for the genome studies and for candidate effector identification. Besides, the high-quality reference genome enabled the design of sensitive markers that allow for the differentiation of different A. psidii biotypes in a biosecurity setting.
  • ItemOpen Access
    Making LGBT health: queer citizenship, community and government in Australia after AIDS
    (2025) Mudford, Isabel
    Making LGBT Health: queer citizenship, community and government in Australia after AIDS Abstract This thesis examines the category of 'LGBT health' and its role in shaping contemporary queer politics. It argues that the formation of this category is constructing, mediating and shaping LGBT subjects and communities. Making LGBT health is based on analysis of interviews with LGBT health organisation leaders and advocates, and analysis of documents and texts produced by these organisations and Australian state, territory and federal governments. It draws on and engages with queer theory and critical work on the politics of public health. The first part of Making LGBT health examines how LGBT health became an established public health concern in Australia. It begins with a genealogical analysis of how gay and bisexual men were constituted as citizens through their relationship with government during the AIDS crisis, and how queer women and trans advocates also utilised the politics of AIDS to make their identities and concerns intelligible. It then explores how the category of LGBT health was mobilised to extend concern about the health of sexuality and gender diverse people beyond HIV, including through the creation of government-led LGBT health strategies. The second part of the thesis comprises three critical analyses of LGBT health discourse and practice. The first examines the response of LGBT health organisations to the outbreak of COVID-19 in Australia, with a particular focus on how HIV figured within their health promotion and advocacy materials. The second examines the constitution of queer women's smoking as a public health problem, with a focus on the discourse of 'minority stress'. The third explores the space and atmosphere of the LGBT clinic and how these spaces both respond to queer discomfort with medicine and materialise some of the concerns of LGBT health. Overall, Making LGBT health argues that public health has become concerned with caring for all aspects of queer life. No longer is public health driven by an imperative to contain non-normative genders or sexualities, or the diseases associated with them. Instead, public health has become concerned with producing healthy and productive queer subjects. While this concern is generating new possibilities for what constitutes healthy LGBT subjectivity and citizenship, it is also producing ideas of the normative and disciplined queer subject, against which non-normative practices are constituted as problems requiring intervention.
  • ItemOpen Access
    Design-driven Materials Intelligence
    (2025) Li, Sichao
    The integration of artificial intelligence (AI) and machine learning (ML) into materials science heralds the era of materials intelligence, AI-driven systems that learn from materials data to predict, design, and optimise structures and properties while embedding domain knowledge. This thesis explores several key challenges at the intersection of AI/ML and materials science: the reliance on single-model explanations, the complexity of capturing non-linear relationships, and the need to balance interpretability with stakeholder expectations. To address these challenges, a thorough literature review is conducted from Chapters 1 to 3, and the thesis emphasises explanations of the same task through diverse similarly performing models. The thesis is structured into three core chapters, guided by design thinking principles: Chapter 4: Rational Design introduces the Variance Tolerance Factor (VTF) framework to address the limitations of single-model explanations, which often generate conflicting insights across models. Using the Rashomon set concept, the VTF framework quantifies feature importance variability, offering a comprehensive perspective. The approach was validated against baseline methods and applied to chemical prediction tasks, demonstrating its utility in enhancing interpretability. Chapter 5: Creative Design builds on rational design by advancing methods to interpret complex feature relationships in materials science. This part introduces Feature Interaction Scores (FIS) and Feature Interaction Scores Cloud (FISC) to explain interactions among features in material property predictions in the Rashomon set. From the study of the Rashomon set in practice, two fundamental axioms are proposed as guidance for generalisability. Chapter 6: Optimal Design utilises explanation disagreement in the Rashomon set as a strategy, bridging the gap between stakeholder needs and ML models. The EXplanation AGREEment (EXAGREE) framework is proposed to align model explanations with stakeholder expectations while preserving predictive performance. This work seeks to improve the alignment between AI systems and the needs of materials scientists, engineers, and other stakeholders in the field. Throughout the thesis, this study explores fundamental challenges in applying ML, especially explainable AI, to materials science, balancing predictive performance with interpretability, satisfying different stakeholder needs, and combining automated optimisation with domain expertise. By advancing methods to address these challenges, this research aims to contribute to the development of trustworthy scientist-centred ML technologies for materials science.
  • ItemOpen Access
    Separating star formation, AGN, and Shocks in Active Galaxies
    (2025) Zhu, Peixin
    The cosmic evolution of galaxies and supermassive black holes (SMBHs) is believed to be correlated through interlinked physical processes. Numerical simulations suggest that active galactic nuclei (AGNs) feedback plays a vital role in governing the growth of the host galaxy. However, observational studies found that AGN does not significantly enhance or deficit the star formation rate (SFRs) in the host galaxy at z<2, making the failure of AGN feedback a mystery. More recently, a study using integral field spectroscopy (IFU) data on galaxy NGC 5728 reveals the presence of positive and negative AGN feedbacks in a single galaxy, suggesting the similarity in total SFRs between AGN-host galaxies and star-forming galaxies may result from the balancing effects of both positive and negative AGN feedback within the galaxy. To better understand how AGNs influence host galaxy star formation and, ultimately, govern (or fail to govern) the growth and evolution of their host galaxies, this thesis tackles the critical bottleneck in studies of the interplay between AGN and star formation and AGN feedback mechanisms: the separation of star formation, AGN activity, and shocks in active galaxies. To address the inconsistencies in existing AGN models, we first construct a reliable AGN photoionization model capable of predicting emission line properties across a broad wavelength range for Seyfert galaxies. Using the new AGN model, we then develop a set of consistent AGN metallicity diagnostics across UV, optical, and infrared wavelengths, which increase the number of available AGN metallicity diagnostics in the literature from around five to more than twenty. Utilizing the new AGN model and consistent HII model and the time-dependent shocks and precursor models, we then build a theoretical three-dimensional (3D) diagram that can simultaneously separate star formation, AGN, and shocks in galaxies with integral field spectroscopy (IFU) data. The inclusion of theoretical models in the new 3D diagram independently constrains the parameter space for each mechanism and provides information on the gas metallicity, ionization states, and shock velocity along with the separation. By applying these new theoretical models on the 3D diagram, we separate the star formation, AGN, and shock in the central ~5 kpc region in NGC 5728. In addition to confirming the star-forming ring and AGN bicone outflow in the galaxy center, we also detect a fast shock-dominated rectangular structure with a length of ~0.5 kpc at the base of the AGN outflow. The presence of fast shocks at the base of AGN outflow is likely associated with a nuclear accretion disk. Applying similar studies to a large sample of galaxies will offer valuable insights into how black hole accretion influences host galaxy growth.
  • ItemOpen Access
    Resemblance Between Microbiomes: How Distance Measures Shape Variation in the Gill Microbiome of Atlantic Salmon
    (2025) Saber, Elle
    This thesis presents a dual investigation into the analysis of microbiome data. The first component involves the collection and analysis of a novel dataset from the Salmon Enterprises of Tasmania Pty Ltd (SALTAS) breeding program. The second line of investigation focuses on a comprehensive characterisation of distance measures used to quantify similarities between microbiomes. Current approaches in microbiome analysis treat the data as "compositional" because it conveys relative abundance information and thus advocate for a log-ratio transformation. However, the prevalence of zeros in 16S rRNA sequencing data violates core assumptions of compositional data analysis. For this reason, throughout the thesis, microbiome data is referred to as "seemingly compositional". Understanding the variation and heritability of the salmon gill microbiome is an open question in aquaculture. Exploratory analysis of the salmon gill microbiome data reveals that there may be a small heritability; however, it is dwarfed by the effect of the environment. It becomes clear during the exploratory chapters how the choice of transformation or distance impacts both the variance we observe and our ability to partition the variation. Inspired by the question of heritability - premised on the idea that closely related individuals should exhibit more similar traits than unrelated individuals - this research investigates what it means for two microbiomes to be similar. The second half of the thesis is devoted to systematically examining how the choice of distance impacts biological interpretation when applied to seemingly compositional data with zeros. Specifically, I compare Aitchison, Euclidean, Jensen-Shannon, and Hellinger distances. Using a range of methods for comparison, including a novel visualisation framework, simulation, and analytical results for the eigenvalues of expected distance matrix, I show that the widely advocated and compositionally valid Aitchison distance can invert the signal and noise in the data, leading to biologically counterintuitive conclusions. In contrast, distances not traditionally considered "compositionally valid", such as Jensen-Shannon and Hellinger distances, demonstrate a better balance between statistical rigour and biological relevance. Notably, the Jensen-Shannon distance emerges as a compromise between the extremes of Aitchison and Euclidean distances, exhibiting a surprising similarity to Hellinger distance. This research introduces alternative ways of understanding and measuring dissimilarities in multivariate phenotypes. It addresses both the practical analysis of a novel microbiome dataset and the theoretical characterisation of distance measures on "seemingly compositional" data. While rooted in quantitative genetics and the study of the salmon gill microbiome, the methodologies and insights extend to broader applications in multi-omics and ecological studies. This contribution enhances the interpretation of complex biological data and supports efforts to improve health and disease resistance in breeding programs through informed strategies.
  • ItemOpen Access
    Improved Reconstruction techniques with the Aid of Ray Tracing for Refractive Index Matching Free Optical Projection Tomography
    (2025) Liang, Zixin
    The global jewelry market demands high-quality, clear, and shiny diamonds, making their quality assessment essential. Clarity and colour are critical aspects of diamond quality evaluation and are investigated in this study. Featuring the use of visible light sources and the detection of light transmission that mimics human vision, this research in optical projection tomography (OPT) was initially motivated by the need to complement the existing optical coherence tomography (OCT) technique. OCT is a 3D imaging method for mapping diamond inclusions based on light interferometry and the detection of back-scattered infrared light. OPT maps the internal features of transparent objects by processing projection images of a target object captured from various viewing angles. However, it suffers from refraction effects due to the use of visible light. These effects are usually mitigated by immersing or embedding the target object in a material with a refractive index closely matched to that of the object. Nevertheless, the index-matching materials used for diamonds are often toxic, complicating operational procedures and limiting the wider application of OPT within the industry. Therefore, this study aimed to use OPT for inclusion mapping of rough diamonds without employing index matching materials, correcting refraction effects computationally instead. Moreover, the use of visible light allows us to imitate human colour perception, facilitating the exploration of colour detection in rough diamonds. Two OPT configurations were developed and examined: laser-scanning OPT, which uses a scanning laser system to capture a complete projection image point-by-point with a photodiode, a single sensing element; and telecentric OPT, which employs a colour camera with a telecentric lens for image acquisition. The latter configuration features a dual-rotation mechanism to improve ray coverage and was chosen for further study primarily due to its faster image acquisition capabilities. The in-software refraction correction is based on a ray tracing process. The light propagation at each viewing orientation is simulated from its generation, its travelling through a high-resolution object surface model created by X-ray computed tomography (XCT), to its detection. In this process, refracted ray paths are computed, and simulated projections are generated, which can be incorporated into an iterative reconstruction algorithm to reconstruct a 3D map of the object's internal features. Additionally, the acquired projection images can be further processed and analysed for diamond colour evaluation.
  • ItemOpen Access
    Managing mature trees for biodiversity conservation in urban environments
    (2025) Parsons, Cara
    Biodiversity is in decline globally with over 400 vertebrate species becoming extinct in the 21st century. Land use change is one of the key contributors, with substantial areas of important habitat still being cleared. A key driver of land use change is the rapid rate of urbanisation. Few studies have examined the contribution of mature trees to biodiversity conservation in urban environments. My research quantifies mature tree loss in urban landscapes, explores the impact on biodiversity, and determines retention strategies. The specific aims are to: a) determine mature tree loss rates due to urban development; b) explore relationships between mature trees and fauna in urban greenspace; c) quantify the risks associated with retaining mature trees in urban areas; and d) identify how residential developments can minimize impact on wildlife dependent on mature trees. This research was conducted across Australia's east coast, focusing on South East Queensland (SEQ), Canberra, and greater Sydney. My thesis comprises four chapters prepared as manuscripts, including one published chapter and three submitted to international journals. A final chapter serves to synthesize the chapters and prescribe management actions to implement the findings of my research. In my first manuscript I investigate the impact of greenfield residential development on mature trees. Here I quantify the reduction in native canopy cover, identify where trees are retained, and evaluate the effectiveness of legal protections. Key findings include: greenfield residential development in reduces native canopy cover by 49%; mature trees are more likely to be retained in remnant vegetation than in urban greenspace or residential blocks; and legislative protections only marginally improve the retention of mature trees. In the next two manuscripts I explore the role of large trees as keystone structures for birds and microbats in urban environments. We conducted bird surveys and deployed ultrasonic bat detectors at 83 sites across Canberra and SEQ. I found positive relationships between the number of large trees and several bird community metrics (species richness, Chao's S, and abundance). I found strongest associations between bird community metrics and numbers of trees >70cm diameter at breast height (DBH) in the ACT, and trees >40cm DBH in SEQ. Of the bird species with strong positive associations with tree size, 73% were hollow dependent. Additionally, I found positive associations between five bat community metrics and the number of large trees >50cm DBH. I also provide evidence that large trees offering equal to greater biodiversity value in landscapes with lower woody vegetation cover. In the fourth manuscript I quantify the risk associated with retaining mature trees in urban environments. I developed models predicting the probability of branch fall in eucalypts to then inform an adjusted version of the QTRA to apply to eucalypts in urban greenspace, including the development of a risk matrix. I demonstrate that even senescing trees can be safely retained in urban areas in dedicated greenspace with low pedestrian occupancy, and away from infrastructure. Overall, my research provides a multi-faceted view of the ecological and practical issues related to retaining mature trees in urban areas. My research reveals that most of the trees retained during residential development are retained in patches of remnant vegetation, rather than as scattered trees. However, I also show that mature trees in isolation have equal if not greater value for biodiversity. This loss of important habitat is contributing to biodiversity loss in urban areas as well as reducing people's access to nature by removing trees from within neighbourhoods. To reverse this pattern of loss, we need stronger regulations to protect mature trees, in combination with better planning systems, ensuring that retention of mature trees is prioritised from the early stages of development.
  • ItemOpen Access
    Banking on Paris: The roles of public green banks in the transition to net zero emissions
    (2025) Lyons, Chell
    Meeting the Paris Agreement goals will require massive public and private sector investments across all sectors of the economy. Using public finance to mobilise additional private sector investment in clean energy investments will be vital. This dissertation investigates the roles of public financial institutions, particularly green banks, in mobilising additional private finance for the net zero transition. The dissertation addresses important gaps in the literature. It makes empirical, conceptual as well as some methodological contributions. Little comparative analysis has been undertaken of public financial institutions mobilising additional private sector investment for climate change. Empirical data on green banks is rare because they are a nascent form of institution, and existing datasets do not capture the technological and financial innovation which underpins their organisational mission. This dissertation begins to fill this gap, adopting a mixed methods approach underpinned by 65 interviews with experts around the world, a systematic literature review and development of a novel dataset exploring the role of Australia's Clean Energy Finance Corporation (CEFC) in accelerating technological and financial innovation in Australia's large-scale solar sector. Theoretically, it draws on economics, institutional political economy and public management theory. It is focused on three key concepts; market failure, market shaping and public value. The dissertation examines the history and development of public green banks, their potential application in developing markets, and how they could operate at the multilateral level. In doing so, it sheds light on the roles of green banks, barriers to investment in scaling up climate finance in different kinds of developing markets, and the capacity of the existing international financial architecture to scale up climate change investment in the Indo-Pacific. It finds green banks play an important role in mobilising additional private sector investment for climate change, that they are perceived to create public value through their investments, and their knowledge-sharing and transparency functions have valuable lessons for other public financial institutions. Chapters in this thesis comprise a typology of public financial institutions mobilising private finance in the transition to net zero emissions (chapter 2), an analysis of how green banks can create multiple types of value in the transition to net zero emissions (chapter 3), a case study of the CEFC and large-scale solar deployment in Australia (chapter 4), examinations of the viability of the green bank model in Indonesia (chapter 5) and Fiji (chapter 6), a conceptual investigation of a multilateral green bank in the Indo-Pacific and key conclusions (chapter 8).
  • ItemOpen Access
    Bound Volume for the degree of Masters of Applied Epidemiology
    (2025) Osborne, Aaron
    This thesis details projects undertaken during my placement at the North Eastern Public Health Unit (NEPHU) from February 2023 to November 2024. I worked at the public health unit before undertaking my Master of Philosophy (Applied Epidemiology) degree. Recently established in 2021, and as the first MAE student to be placed at the Victorian Public Health Unit. My time was valuable for reflecting on how public health and epidemiology had been in the past and how it could be done differently in the future. My projects comprised of: A group A Streptococcus outbreak in a primary school in Melbourne, Australia; Identifying and characterising geographic areas of Hepatitis B incidence in North Eastern metropolitan Melbourne between 2013 and 2022; Local level Hepatitis B care cascade surveillance: A Feasibility Study; Syndromic surveillance for air quality (PM 2.5) related health events: Relationships between ICD-10 codes and periods of poor air quality. This thesis also describes other experiences and public health activities during my placement. These projects and experiences fulfil the core requirements of the Australian National University Master of Philosophy (Applied Epidemiology) program.
  • ItemOpen Access
    Debt Issuance and Asset Revaluation: Firm Heterogeneity, Monetary Easing, and Implications on Investment
    (2025) Wang, Yue
    This thesis investigates the association between debt issuance and asset revaluation, focusing on variations across firm characteristics and monetary regimes, as well as its implications for investment. The thesis is composed of three chapters, each addressing one of the critical aspects above. The first chapter establishes the relation between debt issuance and asset revaluation, with the latter defined as value appreciation for firm stakeholders beyond changes in debt notional, and explores how this relation varies across different types of firms. Using quarterly data from over 7,000 public US non-financial firms spanning 1975 to 2023, we find that active debt management is strongly correlated with value creation. Less established firms---characterized as younger, higher-market-to-book, smaller, lower-leverage, higher-cash, or less profitable---experience stronger effects compared to their counterparts. The value impacts are predominantly accrued to stock price appreciation and net equity issuance. The second chapter analyzes the effect of accommodative monetary policy on how changes in debt levels relate to asset revaluation. We find that active debt management is correlated with stock price appreciation primarily during moderate low-rate periods, while net debt issuance signals increased net equity issuance under broader accommodative monetary conditions. In the cross section, most firm types experience reinforced equity financing under monetary easing, while only younger, value, or smaller firms derive greater stock market benefits from moderate periods of low borrowing costs. The third chapter explores the link between debt issuance and firm investment, demonstrating a strong association between net debt issuance and increased investment activities. Less established firms tend to allocate debt toward net capital expenditure and R&D, whereas more established firms use it for acquisition. The relation between net debt issuance and investment is amplified by low interest rates, emphasizing the role of accommodative monetary policy in fostering business investment. Together, this thesis provides a deeper understanding of how debt financing relates to firm value creation and offers important insights for corporate finance strategies and policymaking.
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