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Design, Synthesis and Characterisation of Platinum and Ruthenium Catalysts for Hydrogen and Oxygen Evolution Reactions
No full textPlatinum (Pt) and ruthenium (Ru)-based electrocatalysts with high stability and activity have gained increasing research interest for water electrolysis, including the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). To maximise stability and activity, the Pt and Ru nanoparticles need to be strategically designed and controllably synthesised at both the atomic and nanoscale levels.
In this thesis, Chapter 1 summarised the key descriptors identified from density functional theory (DFT) calculations for designing Pt- and Ru-based electrocatalysts for HER and OER. It also emphasised the understanding of the structure–activity relationships through examples of nano-structuring, support effects, alloying, and crystal phase. Additionally, recent advances in the solution phase synthesis of these Pt- and Ru-based catalysts were reviewed. Chapter 2 provided the experimental methods used for the synthesis, characterisation, and electrocatalytic evaluation of Pt- and Ru-based nanoparticles. Besides, the methods for DFT modelling and calculations were included. Chapter 3 investigated the interaction of reaction intermediates, hydrogen and hydroxide, with two facets of Pt(111) and Pt(100) using DFT calculations, guiding the design of Pt catalysts for HER at an atomic level. In Chapter 4, the open Ru branches were designed and synthesised by growing off the corners of Pt nanocubes. These open Ru branched nanoparticles exhibit significantly improved electrochemical surface area. Coupled with low-index facets exposed on the branch surface, the acidic OER activity and stability are enhanced. In Chapter 5, the Ru was directly grown onto the surface of Pt nanocubes with controlled surface coverage, forming a Pt-core Ru-shell structure. The tuning of the Ru coverage weakens the adsorption energies of hydrogen and hydroxide and achieve enhanced activity and an improved reaction kinetics for alkaline HER. In Chapter 6, shape-controlled synthesis of Pt nanoparticles was examined, and their use as seeds for the growth of Ru was successfully achieved. Multiple Ru branches and islands were grown on the surface of Pt nanoparticles with multiple Pt-Ru interfaces. This demonstrates the robustness of the synthetic procedure developed in Chapter 4 and 5, and these catalysts are promising in catalysing HER and other electrochemical reactions. Chapter 7 provides a summary and outlook on the rational design and synthesis of Pt-Ru nanoparticles for HER and OER
Towards a gender inclusive urban environment: modelling crowdsourced perceptions of safety
No full textPerceptions of safety are increasingly recognised as an important indicator of gender inclusion and accessibility in cities. Yet, there is a limited understanding of what contributes to safety perceptions and how they manifest across urban environments. The rise of crowdsourced spatial information on safety perceptions means there is an opportunity to use such data to address the requirements of gender-inclusive cities. The aim of this research is to examine how crowdsourced information can be used to learn more about what contributes to safety perceptions in urban places.
Safetipin and She’s A Crowd are two platforms that use location technology to crowdsource information related to safety. Using data from both platforms, I applied statistical and environmental modelling techniques to explore the factors driving safety perceptions.
By incorporating time and location, I identified the primary drivers of safety perception for five cities in India using Safetipin data. Across two studies, perceived safety was governed by the individual completing the safety audit, the presence of women, and lighting. While hypothesised to greatly influence safety perceptions, gender and timing had little to no effect. Included predictors capture more than 50% of the variation in safety perception, though a substantial portion remains unexplained.
For my final study, I examined the distribution of negative safety perceptions in the City of Sydney, Australia. Using She’s A Crowd data, the three most influential factors comprise location, average daily walking counts, and distance to public transport. Results suggest that factors beyond the included predictors may be driving the distribution of negative safety perceptions. Regardless, observed relationships have important implications for urban planners seeking to design places that feel safe.
Findings highlight the potential of crowdsourced information in the field of safety perception studies, yet more research is required to fine-tune data collection methodologies, identify relevant personal, social and environmental predictors and strengthen subsequent analyses. While there are limitations to this framework, my research has contributed to the improved capacity of crowdsourced safety perceptions for evidence-based decision-making in city planning. Everyone deserves to feel safe in public spaces – we now have the roadmap to help make that happen
On the ethical and moral dimensions of using artificial intelligence for evidence synthesis
No full textArtificial intelligence (AI) is increasingly being used in the field of medicine and healthcare. However, there are no articles specifically examining ethical and moral dimensions of AI use for evidence synthesis. This article attempts to fills this gap. In doing so, I deploy in written form, what in Bengali philosophy and culture, is the Adda (আড্ডা) approach, a form of oral exchange, which involves deep but conversational style discussion. Adda developed as a form of intellectual resistance against the cultural hegemony of British Imperialism and entails asking provocative question to encourage critical discourse.The raison d’être for using AI is that it would enhance efficiency in the conduct of evidence synthesis, thus leading to greater evidence uptake. I question whether assuming so without any empirical evidence is ethical. I then examine the challenges posed by the lack of moral agency of AI; the issue of bias and discrimination being amplified through AI driven evidence synthesis; ethical and moral dimensions of epistemic (knowledge-related) uncertainty on AI; impact of knowledge systems (training of future scientists, and epistemic conformity), and the need for looking at ethical and moral dimensions beyond technical evaluation of AI models. I then discuss ethical and moral responsibilities of government, multi-laterals, research institutions and funders in regulating and having an oversight role in development, validation, and conduct of evidence synthesis. I argue that industry self-regulation for responsible use of AI is unlikely to address ethical and moral concerns, and that there is a need to develop legal frameworks, ethics codes, and of bringing such work within the ambit of institutional ethics committees to enable appreciation of the complexities around use of AI for evidence synthesis, mitigate against moral hazards, and ensure that evidence synthesis leads to improvement of health of individuals, nations and societies
Friends of the Australian High Court: Amici Curiae in Constitutional and Public Interest Litigation
No full textThis thesis explores the use of amicus curiae by civil society interest groups in Australia’s apex court, the High Court of Australia, in constitutional and public interest litigation. Apex courts regularly decide on controversies that carry significance to the broader public beyond the parties involved in litigation. Accordingly, they are often a forum for non-party interests to speak to the court through the mechanism of amicus. However, unlike the significant scholarship on the role of amicus in the United States Supreme Court, there is scarce research on amicus involvement in other apex courts, including Australia. While some Australian scholarship has laid amicus groundwork, a shortage of data and qualitative insight has meant empirical records are thin—and incomplete.
This thesis aims to understand when, how, and why civil society interest groups—including public advocacy groups and public interest legal centres—have been involved as amicus in the High Court. These questions are addressed through a mixed-method approach, utilising doctrinal analysis and empirical data, and informed by theories of legal mobilisation and resource mobilisation. The thesis compiles a historical quantitative dataset of amici in the High Court, enhanced by qualitative and practical insight from 29 amici participants (solicitors, barristers, judges, and civil society representatives) involved in amici matters in the High Court.
The thesis finds a rich history of amicus mobilisation in constitutional and public interest matters. It explores structural aspects in the Australian legal context that allow, or hinder, amicus involvement. Most significant among these structures is the resource role of lawyers, both solicitors and barristers, in the amicus ecosystem. The thesis also considers how institutional features, such as the High Court’s Rules and judicial receptivity, shape amici participation. Additionally, it explores qualitative experiences including how financial resources shape participation, highlighting that amicus is viewed favourably as a low-cost legal advocacy pathway for civil society actors, and that pro bono support has assisted organisations—who are otherwise resource constrained—to become involved as amicus. Finally, it examines how amicus legal arguments are drafted, as well as experiences of amici legal counsel during oral argument in the Court. Overall, this thesis illuminates a range of contemporary aspects of amicus practice in the High Court, which will better inform prospective actors contemplating involvement as amicus in the future
Model rural health research units in India: A research priority setting exercise
No full textBackground & Objectives: Research in rural health has historically been opportunistic, lacking alignment with strategic goals or community needs. The Government of India established Model Rural Health Research Units (MRHRUs) to address these disparities through targeted research. However, inconsistent outputs highlight the need for a strategic research agenda. Identifying research priorities is critical to inform policy and funding strategies of MRHRUs. Methods: A nationwide Research Priority Setting (RPS) exercise was conducted, involving 120 respondents for free listing of questions, and 250 for ranking. Respondents from various stakeholder groups, including policymakers, researchers, and community representatives, participated. Research priorities were categorised into three domains – Description, Development, and Delivery. An iterative process was employed to refine and consolidate the 122 research questions into 36, which were subsequently ranked using a scoring system that assessed their importance, feasibility, and impact. The list of priorities was finalised through stakeholder deliberation. Results: The top five research priorities across the three domains addressing key rural health challenges as identified in this study are presented. ‘Descriptive’ priorities included investigating social determinants of hypertension, medicine supply chain bottlenecks, and mental health in the elderly. ‘Development’ priorities focused on interventions using electronic health records in hospitals, tuberculosis control, and menstrual hygiene education. ‘Delivery’ priorities emphasised improving healthcare resilience, emergency care, and technology-driven diabetes management. These priorities were disseminated to MRHRU managers and policymakers to guide decisions with regard to perceived priorities for research in rural health. Interpretation & conclusions: This first-of-its-kind RPS exercise provides inputs towards a strategic roadmap for rural health research, ensuring that future studies align with the needs of rural populations, leading to improved health outcomes. These findings illustrate perceptions and priorities of a selection of respondents from different stakeholder groups and need to be taken into consideration by the Department of Health Research and at the local level by each of the MRHRUs
Previous-day drug expenditure among a sample of people who inject drugs, 2024
Full text linkThe Illicit Drugs Reporting System (IDRS) is a national drug monitoring system that has been conducted annually since 2000. Its purpose is to identify emerging trends of local and national concern in illicit drug use and markets. The system is part of the broader Drug Trends program. This bulletin aims to examine previous-day drug expenditure among a sample of people who inject drugs, using data from the 2024 IDRS
Development of novel combination therapies targeting MYC oncogenes and overcoming chemo-resistance through single cell profiling for high-risk childhood cancers
No full textPaediatric cancers encompass a range of malignancies that present as solid tumours or blood cancers in children. Despite advancements in drug discovery, it remains the leading cause of disease-related mortality among children. Paediatric cancers exhibit differences from adult cancers in their biology, origin and treatment, which complicates efforts to apply existing efficacy and safety data from new therapies discovered in adult cancers to paediatric cancers. A deeper understanding of the molecular pathways of drug resistance in paediatric cancers, and the development of novel single or combination therapies for the treatment of high-risk childhood cancer are needed.
Medulloblastoma is the most common malignant brain tumour in children, accounting for 20% of all childhood CNS malignancies. High-risk medulloblastoma is often associated with overexpression of MYC/MYCN oncogenes and correlates with poor prognosis in patients. To date, there are no approved MYC inhibitors, making it difficult to treat MYC-driven medulloblastoma. In the first two research chapters, the novel small molecule compound, UNSW-SC-22 was identified to inhibit tumour growth in vitro and in vivo in MYC-driven medulloblastoma. Mechanistic studies showed that the activity of UNSW-SC-22 was dependent on MYC, and that UNSW-SC-22 was able to target and bind to MYC, disrupting MYC stability and inducing apoptosis, DNA damage and cell cycle arrest. Additionally, the combination of UNSW-SC-22 with histone deacetylase inhibitors was found to be synergistic in MYC-driven medulloblastoma cells.
On an alternative front, osteosarcoma is another MYC-driven cancer and is an aggressive bone tumour characterized by a heterogeneous tumour composition that facilitates resistance to conventional chemotherapy. In the final research chapter, drug resistant mechanisms in osteosarcoma were explored through single cell RNA sequencing of primary osteosarcoma patient tumours at diagnosis and post-chemotherapy. This revealed MRE11 as a potential driver of chemo-tolerant persister cells in osteosarcoma, and inhibition of MRE11 alone, in combination with chemotherapy or UNSW-SC-22 was shown to be effective in osteosarcoma cell lines. The combinations were also shown to synergistically induce DNA damage pathways in osteosarcoma.
Collectively, this thesis has identified and characterized novel single and combination therapies that could allow for better treatment options in patients with high-risk paediatric cancers
Advancing Strategies for the Removal, Detection, and Biochemical Interaction Assessment of Per- and Polyfluoroalkyl Substances (PFAS)
No full textPer- and polyfluoroalkyl substances (PFAS) are rapidly becoming one of the most concerning emerging contaminants in the 21st century. The production of PFAS for domestic applications such as non-stick cookware and for industrial applications in aqueous film-forming foams has led to the contamination of ecosystems worldwide. With some PFAS classed as cancer causing compounds, there is a need to detect, remediate, monitor and assess the implications of PFAS globally. This thesis describes the advancements of techniques to achieve the low detection limits required for PFAS required in drinking water supply and the aid the characterisation of PFAS binding to proteins commonly found in the human body. Chapter 2 describes the use of metal-organic frameworks (MOFs) as dual functional sorbents for the removal of PFAS from water and the detection of PFAS at ultra-trace concentrations. Using UiO-67 for the removal of PFAS, 99% of a 2 parts per billion solution were removed from water. Additionally, the use of UiO-66 for the quantification of PFAS resulted in average detection limits of 144 parts per quadrillion (ppq), with the lowest detection limit of 17 ppq. To understand the mechanisms that allow MOF materials to effectively capture PFAS from aqueous solutions, Chapter 3 focuses on the kinetic and thermodynamic properties of MOFs that allow these materials to effectively capture PFAS from water, where the availability of a range of pore sizes was an important factor for PFAS removal by MOFs. Chapter 4 focuses on the quantification of 50 PFAS in drinking water samples collected around Sydney, where the quantification of ultra-trace levels of PFAS in 33 tap and 12 bottled water samples revealed a total of 31 PFAS in drinking water supply, where two PFAS are previously undetected in global drinking water supply. To aid the characterisation of PFAS binding to proteins, Chapter 5 describes the development and optimisation of a competitive semi-quantitative binding affinity assay to quantify the extent of 50 PFAS binding to four target proteins. The binding of small molecules to proteins can potentially alter their functions such as enzymatic activities, which can adversely impact normal biochemical processes. 44 PFAS out of 50 PFAS screened were identified as binding PFAS to one of four target proteins, with 40 PFAS identified for human serum albumin, where 28 are newly reported PFAS-protein interactions
Ecology and interactions of dingoes in a human-modified landscape
Full text linkEffective wildlife management requires detailed knowledge of a species’ behavioural ecology, including intra- and inter-specific space use patterns. This is especially true for species that come into direct contact with people, potentially resulting in human-wildlife conflict. Elusive and cryptic species, however, can be hard to observe in the wild, making it difficult to study the mechanisms driving their behaviour, particularly before the advent of GPS tracking devices and remote camera traps.
The dingo (variously referred to as Canis dingo, Canis familiaris, Canis lupus dingo, amongst others), is a controversial Canid species present across mainland Australia, and is heavily suppressed or extirpated by anthropogenic lethal control in many areas. Generally difficult to observe in the wild, dingoes are a problematic species, imposing considerable economic costs on livestock producers, particularly sheep farmers. Additionally, they can sometimes cause direct danger to human safety, particularly where they have been provisioned with food and consequently display limited fear of people. Dingo management approaches are much debated, as dingoes are accepted and even revered by some of the population as a critical part of ecosystem function and an iconic Australian species with intrinsic value. In contrast, others experience dingoes as a pest to be removed. Adding to these contrasting attitudes is the debate of whether or not the dingo should be considered a native or introduced species.
Despite their controversial status, there is limited literature on the behavioural dynamics of dingoes. Much of the published research focusses on population trends after lethal control, their effects as trophic regulators, and their taxonomic status. A series of 6 studies published in the early 1990s by Peter Thomson on dingo behavioural ecology in desert ecosystems is one of the key works cited for dingo behaviour and was based on VHF-only radio tracking and direct observations. There have been considerable technological advancements since these studies, and the opportunity has arisen to increase our knowledge of dingo behaviour, and indeed add to the global literature on canid behaviour.
In this thesis, I present research chapters on several understudied aspects of dingo behavioural ecology in coastal New South Wales, Australia. In this region dingoes regularly encounter humans, resulting in management challenges and human-wildlife conflict. Using remote camera traps, in some sections combined with GPS collars and direct observations, this thesis evaluates dingo population size and dynamics (chapter 2), quantifies seasonal changes in dingo movement across the landscape (chapter 3), evaluates temporal and behavioural patterns of dingo scent marking site use to maintain territories (chapter 4), describes the responses of dingoes to the deaths of dominant dingoes in adjacent packs (chapter 5), outlines a method for estimating carnivore territories and pack structure/composition from camera trap data (chapter 6) and finally assesses spatial and temporal activity patterns within dingo home ranges, and the potential effect(s) on smaller, competitively inferior, mesopredators (chapter 7).
I found the highest population density of dingoes currently reported in New South Wales, and showed that dingo density increased with proximity to areas with high human population density, perhaps suggesting that dingoes are accessing anthropogenic food sources in these areas. I found that subordinate male dingoes undertook more extraterritorial forays during the breeding season than dominant individuals. In addition, dominant individuals were detected proportionally more within their home range than outside their home range, as the number of pups in their pack from the previous year increased. I also found that dingo use of scent marking sites increased markedly in the breeding season, and I present evidence suggesting that male dingoes use these sites to overmark their mate. Collectively, this suggests that scent marking plays a role in mate defence in dingoes and is not solely related to defending non-breeding resources (i.e. food and space per se) from adjacent packs. In a natural history note, I show that the deaths of two dominant male dingoes were followed by a period territorial breakdown and subsequent re-establishment. I also showed that camera traps can be used to accurately infer territorial boundaries, potentially providing researchers and land managers with a cost-effective method to estimate pack structures and density without the need for more invasive research approaches, such as capture and collaring. Finally, I found that the space use of three mesopredators was inversely related to dingo space use, although this may have been confounded by preference for urban areas by dingoes. Red foxes (Vulpes vulpes), a species that tends to be found at higher densities in urban areas, were never detected in an urban area in our study region, potentially due to suppression by dingoes. By contrast, I found that an endangered native mesopredator, the spotted tailed quoll (Dasyurus maculatus), and a native reptile, the lace monitor or goanna (Varanus varius), had high population densities overall, despite also being absent from this urban area. While dingoes may exert direct negative pressures on lace monitors and quolls, spatial and temporal detection patterns suggest that dingoes potentially ‘shielded’ quolls and monitors from the negative impacts of red foxes, which may be a more significant competitor for these two mesopredators than the dingo is.
Effective wildlife management is dependent on a thorough understanding of the behavioural ecology of the managed species and its impacts on other species in the ecosystem. The knowledge presented in this thesis adds to the broader understanding of dingo behaviour and will improve our collective management of this species and its impacts