Open Access Theses
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Item Open Access Between Eagle and Dragon: Analyzing Indonesia’s Hedging Behavior under Joko Widodo Administration (2014-2024)(2025) Basundoro, Alfin FebrianThis 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.Item Open Access Evaluating plant-pathogen interactions in classical biological control of weeds: Kordyana brasiliensis released against target weed Tradescantia fluminensis in Australia(2025) Zeil-Rolfe, IsabelTradescantia 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.Item Open Access Long Term Laser Frequency Readout for Space Based Interferometry(2025) Rees, Emily RoseFuture 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.Item Open Access Knowledge Graphs and Natural Language: two sides of the same coin(2025) Papaluca, AndreaIn 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.Item Open Access "We are Living in a World not Meant for Us": A Study About Why Girls Are Not Allowed to be Autistic(2025) French, SusannahIn 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.Item Open Access Genome biology of rust fungi and applications for biosecurity(2025) Luo, ZhenyanFungal 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.Item Open Access Making LGBT health: queer citizenship, community and government in Australia after AIDS(2025) Mudford, IsabelMaking 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.Item Open Access Design-driven Materials Intelligence(2025) Li, SichaoThe 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.Item Open Access Separating star formation, AGN, and Shocks in Active Galaxies(2025) Zhu, PeixinThe 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.Item Open Access Resemblance Between Microbiomes: How Distance Measures Shape Variation in the Gill Microbiome of Atlantic Salmon(2025) Saber, ElleThis 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.Item Open Access Managing mature trees for biodiversity conservation in urban environments(2025) Parsons, CaraBiodiversity 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.Item Open Access Banking on Paris: The roles of public green banks in the transition to net zero emissions(2025) Lyons, ChellMeeting 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).Item Open Access Bound Volume for the degree of Masters of Applied Epidemiology(2025) Osborne, AaronThis 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.Item Open Access Debt Issuance and Asset Revaluation: Firm Heterogeneity, Monetary Easing, and Implications on Investment(2025) Wang, YueThis 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.Item Open Access Active and nonreciprocal Nanophotonics(2025) Tripathi, AdityaRecently, the field of nanophotonics has seen rapid developments in the area of dielectric metasurfaces governed by Mie scattering. The dielectric metasurfaces have shown remarkable versatility of their functionalities. Ranging from Huygens metasurfaces controlling directionality and phase of light scattering to sharp Fano-resonators to quasi-BICs and nonlinear metasurfaces supporting higher order nonlinear effects. However, active and nonreciprocal nanophotonics with metasurfaces has been facing challenges like miniaturization to the nanoscale and extreme suppression of Mie scattering by active media. Active and nonreciprocal metasurfaces acting as light sources and switches were difficult to realise. The last seven years several different strategies for the harmonious combination of optically active media and dielectric metasurfaces have been developed and demonstrated. However, the scope of fundamental approaches, detailed methodology and experimental demonstration of functional active nanophotonic devices remained a challenge. This hindered the development of active and nonreciprocal metasurfaces from fundamental to applicaitons as prospective nano-optical devices. In my Thesis, I focus on the design, development and demonstration of working active and nonreciprocal nanophotonic devices and their practical applicability as prospective nano-optical devices. I developed a general framework for design and demonstrated both light generation, active light modulation and directional control capabilities in the near infrared wavelength range. Amongst light sources, I demonstrated the capability to generate polarized luminescence at the nanoscale as well as nanolasing. And in case of light modulation, I demonstrated amplitude modulation and spectral modulation. The directional control is shown in nonreciprocal transmitters. Ultimately, I addressed the design and development challenges in the realization of nano-optical devices and their role in emergence of nanophotonics as a major player in upcoming industry. In, Chapter 1 I describe the overall motivation behind this work and the concept of active and nonreciprocal nanophotonics in detail. Chapter 2 delves into the methods used (both theoretical and experimental) throughout this research. Chapter 3 and 4 elaborate on the design of active metasurfaces as light sources. Specifically, Chapter 3 talks about active metasurfaces which can produce polarized photoluminescence. These metasurfaces rely on coupling of polarized scattering from dielectric nanoparticles to the nanoparticles of rare earth doped nanoparticles. Our work is one of the first approaches that demonstrate polarization control in fluorescence emission from rare earth nanoparticles. In Chapter 4, highly confined fields are generated in membrane based dielectric nanostructures which have thin layers of quantum wells sandwiched within them leading to the earliest demonstration of topological and anapole nanolasing at room temperatures. In Chapter 5, I elaborate on the maiden demonstrations of nanophotonic nonreciprocal light control devices. The light control is achieved by the deployment of a layer of phase change or highly nonlinear materials in the structure of the metasurface. First, I demonstrate amplitude and spectral modulation using vanadium dioxide based metasurafes. Next, I show nonreciprocal transmission using ITO based metasurfaces. In the final chapter, I summarise my findings and outline the future scope.Item Open Access Essays on International Trade and Development: Evidence from Indonesian Microdata(2025) Laksono, RiandyNo country has achieved significant development without engaging in international trade. However, this insight faces scrutiny as developing countries struggle to reach their potential despite open trade regimes. This thesis presents four empirical papers examining how international trade impacts various development aspects, using rich Indonesian microdata at both firm and individual levels. The first analytical chapter (Chapter 4) examines trade liberalization's effect on labor share of income in Indonesian manufacturing from 1990-2015. The analysis reveals that reduced trade protection led to the emergence of superstar firms with superior performance and lower labor costs, ultimately reducing labor's income share through market share redistribution. Unlike developed nations where declining labor share coincided with increased market power, Indonesia's manufacturing firms maintained stable market power, suggesting a unique mechanism of trade reform's influence on labor share dynamics in a developing economy context. Chapter 5 revisits the market discipline hypothesis of trade, which posits that exposure to international trade could limit firms' market power. Using the case of trade liberalization in Indonesian manufacturing, I show that the impact of trade liberalization on competition, measured by markup, will depend on the nature of liberalization itself. While output tariff liberalization creates a market-disciplining effect for firms by reducing markup, this effect is outweighed by input tariff liberalization, which increases firms' markups at a much higher level due to the efficiency effect of cheaper materials. This occurs because competition in Indonesia's manufacturing sector is imperfect, giving firms price-setting power. Thus, the pass-through from cost to price is likely to be incomplete, making the reduction of cost end up in higher markup. In this case, however, although both firms and consumers gain in absolute terms following liberalization, the distribution of the gain favors firms more than consumers. Chapter 6 deals with the trade and productivity nexus but views it through the lens of allocative efficiency rather than within-firm efficiency improvement extensively discussed in existing studies. Chapter 6 examines trade and productivity through allocative efficiency rather than within-firm improvement. The shift of market share towards more productive firms drove productivity growth in Indonesian manufacturing, particularly in the 1990s, though this pace slowed significantly after 2000. Trade liberalization improves allocative efficiency by reallocating market share towards productive incumbents, forcing less productive firms' exit, and reducing industry distortion. This suggests trade liberalization's crucial role in reducing resource misallocation that hinders developing countries' growth potential. The last analytical paper in Chapter 7 aims to understand the impact of export expansion to China on labor market outcomes among workers. To broaden the perspective, we include not only the commodity exports but also the manufacturing ones. We find that individuals living in the regions more exposed to export expansion to China experienced improved formal job opportunities. Export expansion also proved relatively progressive, raising formal employment opportunities and earnings growth particularly for lower- and middle-income classes. These results stem from manufacturing exports' expansion within a largely commodity boom period.Item Open Access Analog Control of the Diamond Quantum Processor(2025) Stearn, SophieDiamond quantum processors, based on the nitrogen-vacancy (NV) centre, offer long coherence times and high-fidelity optical control at room temperature, making them a promising platform for quantum technologies. Until now, they have been operated almost exclusively using the gate-based digital quantum computing (DQC) paradigm. This thesis introduces a novel derivation of the fully controllable Ising model from the diamond control Hamiltonian, laying the groundwork for this architecture to support computational paradigms beyond the gate model. With this result, analog control becomes feasible on diamond hardware for the first time, enabling a novel approach to quantum annealing. Diamond quantum annealing is evaluated through simulations of a room-temperature device based on a single NV-centre cluster, incorporating realistic effects such as decoherence and crosstalk. To improve robustness, open-loop optimisation protocols are introduced for annealing schedule design, showing improved performance. A new hardware-specific quality factor is also proposed, which benchmarks adiabaticity based on the system's minimum transition frequency spacing and decoherence time. This metric suggests that diamond may support purely quantum annealing, without relying on thermalisation. For contrast, the metric is applied to both the proposed diamond quantum annealer and superconducting flux qubit devices, using parameter estimates from D-Wave's Advantage platform. Finally, this work demonstrates that diamond is also capable of stepped digital-analog quantum computation (sDAQC), marking a second potential shift in how quantum algorithms can be realised on this platform. Building on this result, a hardware-specific technique- interleaved circuit compression (ICC)- is also introduced to exploit the newly derived control Hamiltonian. By combining Ising coupling gates with arbitrary-axis rotations, ICC enables substantial compression of gate-based quantum circuits on diamond hardware. This is illustrated using the quantum Fourier transform (QFT), where circuit depth is reduced from O(n^2) under standard digital compilation to O(n) with ICC.Item Open Access A Dialogue Between Nature and Culture: An Ethnography of the Talesh People's Calling Tradition(2025) Jahandideh, MitraThis thesis examines khele, a calling tradition of the Taleshi people in Iran, who primarily live in the county of Talesh in Gilan province, located on the southwestern coast of the Caspian Sea. Rooted in the region's diverse geography, which includes coastal areas, plains, foothills, and mountains, khele initially served as a practical communication tool for ranching, farming, and fishing activities. Over time, khele developed into a cultural practice performed at local concerts, representing the Taleshi nomadic and agricultural lifestyle and evoking memories of rural life. This research explores how khele reflects the social, occupational, and emotional aspects of the Taleshi rural life, highlighting the people's relationship with their environment. It also investigates how khele contributes to the formation of cultural identity, memory, and a sense of belonging and well-being among the Taleshi communities. To examine these dynamics, I employed an ethnographic approach that included observational ethnography, netnography, soundscape recordings, and interviews (individual, feedback, and walking) conducted in the living and working places of the Taleshi people over a period of 12 months. The findings demonstrate that khele acts in different ways: practically for communication, emotionally for self-expression, and symbolically in cultural performances. Khele is an important cultural marker that connects the community to the past through memory, sound and place. This thesis also demonstrates how khele has changed in response to urbanization and technological changes, shifting from a daily tool to a cultural symbol in performances and gatherings. This shift highlights the resilience of the Taleshi people, who have preserved their cultural heritage while adapting to modern life. This thesis contributes to ethnomusicology, anthropology and sound studies by providing a conceptual framework for understanding traditional and transformed calls, and demonstrating how calling traditions shape cultural and ecological understandings. It highlights the role of soundscape and landscape in constructing cultural meaning and memory, while also providing insights into the broader impact of sound in human-environment interactions. This work shows how khele represents the sonic world of the Taleshi people and contributes to the ongoing transformation of their cultural heritage.Item Open Access Ocean Gyres Driven by Wind Stress and Surface Buoyancy Forcing(2025) Bhagtani, DhruvLarge-scale ocean circulation is central in modulating weather and climate patterns by distributing heat, nutrients, and carbon dioxide within and across ocean basins. The large-scale circulation is driven by processes at the ocean's surface (such as winds and heat and freshwater fluxes) and steered by processes in the ocean's interior (such as mesoscale eddies and flow-topography interactions). Climate change is expected to alter these surface forcings. Despite the central role of ocean circulation in transporting heat and regulating climate, the impact of physical processes both at the ocean's surface and in the interior on the large-scale ocean circulation -- especially in the context of climate change -- remains inadequately understood. In this thesis, we focus on two large-scale circulatory ocean features: (i) the gyres (primary focus of the thesis), and (ii) the Atlantic Meridional Overturning Circulation (AMOC). Ocean gyres are canonically believed to be driven by wind stress, while the AMOC is thought to be controlled by surface buoyancy forcing (i.e., heat and freshwater fluxes). Using a series of ocean model simulations, we find that in addition to wind stress driving gyres, surface heat fluxes control the near-surface density gradients, which in turn affect the gyre circulation. The relationship between surface heat flux gradients and the gyre circulation is linear for timescales shorter than a decade, after which the relationship becomes non-linear due to density advection by the circulation. A major focus of this thesis is the North Atlantic basin, where the heat carried from the tropics to the Arctic by the subtropical gyre and the AMOC is sensitive to both changes in winds and surface heat fluxes. On timescales shorter than a decade, changes in each circulation's heat transport occurs primarily through anomalies in the circulation strength. On multidecadal timescales, changes in the ocean's temperature feed back to modulate the heat transport response. Last, we focus on a key atmospheric mode of variability, the North Atlantic Oscillation (NAO), and how it affects the ocean circulation. While the NAO impacts the gyres through changes in winds and surface buoyancy fluxes, the relative importance of processes at the ocean's surface and in the interior in shaping the gyres is not fully understood. We find that NAO-induced changes in the surface wind stress drive more than 90\% of the variability in the subtropical gyre. In contrast, in addition to wind stress, the NAO-induced variability in the subpolar gyre is governed by several processes: mesoscale eddies, flow-topography interactions and the ocean's stratification (influenced by surface heat fluxes). Our work emphasizes the under-appreciated role of surface buoyancy fluxes in driving oceanic gyre circulations, with implications for how the gyres, and thus regional climate, may change in the future.Item Open Access Sense of self and belonging in university students participating in orientation program(2025) Walker, SarahOrientation programs and the overall transition period are a critical time for students commencing within higher education. Research has demonstrated what occurs during this time will impact on a student's engagement (Kift, 2009; Krause & Coates, 2008; Tinto, 1994), retention (Krause et al., 2005), and wellbeing (Pascarella & Terenzini, 2005). Similarly, research has highlighted the importance of sense of belonging for university students to support academic engagement (Freeman et al., 2007; Iyer et al., 2009; Smyth et al., 2019) and retention (e.g. Hausmann et al., 2007; Hoffman et al., 2002; Strayhorn, 2019). Sense of belonging has become a cornerstone for improving the experiences and outcomes for students from traditionally underrepresented backgrounds (Hurtado & Carter, 1997; Strayhorn, 2019; Walton & Cohen, 2007, 2011). However, there are clear gaps in the current literature as research on the impact of orientation programs does not measure sense of belonging, even when this is a key purpose of the program. Additionally, while there have been indications that sense of belonging fluctuates over time, there is not an understanding of how or when this occurs, limiting the potential impact of interventions aimed at increasing sense of belonging. This thesis seeks to address these gaps through five studies which examine the limitations within the current literature and to continue building our understanding of the importance of sense of belonging to students transition and ongoing experience within higher education. Utilising a systematic review, primary and institutional survey data, and interviews, these studies demonstrate the importance of sense of belonging during the transition period as well as the impact that it can have for students throughout their studies. The findings will also highlight the need to intentionally focus on sense of belonging for the benefit of all students, and how in particular, it is vital for those students from traditionally underrepresented backgrounds.