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Conservation of Caladenia (Orchidaceae) under a Changing Climate
No full textThe Orchidaceae is one of the most diverse and threatened plant families globally, with almost 3.5% listed as threatened and many more being data deficient likely underestimating the number of the threatened orchid species. This is partly due to their reliance on Orchid Mycorrhizal Fungi (OMF) for germination, growth and further development and their complex environmental niches and microsite requirements that make them sensitive to environmental change. Climate change is a major, and overlooked, threat to orchids, with only 17% of International Union for Conservation of Nature (IUCN) listed species considered under threat by climate change.
Re-introduction and translocation are common conservation practices utilised in threatened orchid management and recovery plans. However, their effectiveness is widely debated, with many re-introductions and translocations failing to produce self-sustaining populations. Furthermore, there are limitations to success at each stage of the re-introduction/translocation process; for example: poor in-vitro germination success, poor survival rates when transferred to pots or poor survival rates after re-introduction. The low success varies case-to-case but is likely a result of a lack of consideration for the specific microsite conditions for the orchid and its OMF. This thesis presents novel approaches to improve conservation outcomes in Caladenia (and possibly other orchid) species by improving our understanding of microsite condition in situ, including environmental responses, to inform the re-introduction/translocation process with future climate predictions in mind.
Long-term (12 years) vital rates of wild, re-introduced and translocated populations of the endangered terrestrial orchid, Caladenia amoena (Charming Spider Orchid), were compared, which demonstrated that re-introduction and translocation were insufficient at establishing self-sustaining populations during the 12-year study period. When relating vital growth rates to climate, emergence and flowering declined as mean maximum temperatures rose, whereas flowering increased with rainfall. Both emergence and flowering were positively correlated with the length of the growing period, which decreased by >33% during the study, highlighting it as a key concept and possibly the biggest challenge in preventing further population decline.
Similar negative correlations between emergence and flowering and temperature were observed in endangered Caladenia robinsonii (Frankston Spider Orchid), suggesting declines will continue given the current predictions of +1 to +3°C of warming by 2051 at its only known location. Using Principal Components Analysis (PCA) and General Linear Modelling (GLM) to compare soil properties and vegetation characteristics among re-introduced and wild populations identified greater nitrate concentration, graminoid cover and canopy tree distance and an open small shrub layer as common characteristics in the better performing populations.
Understanding in-situ conditions of C. robinsonii helped to improve in-vitro germination and identified three critical factors for germination, namely conducive conditions, ‘ready-to-germinate’ seed and effective mycorrhizal fungi. The positive effects of warm stratification on germination and seedling development were demonstrated for the first time, more than tripling germination and stage 4 seedling development compared to non-stratified seed. When comparing germination and OMF growth, there is a narrow overlap between the most favourable conditions for the orchid seed and OMF growth and only within this overlap can most seeds germinate and seedlings develop.
Elucidating OMF responses to climate was investigated using real-time polymerase chain reaction (qPCR) and a Serendipita-specific primer (C. robinsonii’s OMF). Soil abundance of Serendipita changed with season but not in response to mean monthly maximum (MMmax) and mean monthly minimum (MMmin) air and soil temperature or mean monthly (MM) rainfall. Serendipita OMF abundance in soil was less in declining populations than in stable/increasing populations. This is the first study to investigate the response of a free-living OMF in soil to seasonal variation in OMF abundance and soil moisture, temperature and rainfall, and suggests that the predicted changes in temperature and rainfall will probably not directly affect this free-living OMF. If free-living OMF abundance is not expected to be impacted by climate, focus should be given to other factors such as microsite conditions, particularly those favourable to in-situ recruitment, which is essential for establishing self-sustaining populations and to halt declines.
Microsite factor differences between recruiting and declining clusters of C. robinsonii were investigated using a variety of statistical methods including linear regression, GLM and PCA. Soil moisture, ground cover and OMF abundance were important factors for seedling recruitment. A soil OMF abundance of ≥1.5 ng μL-1, bryophyte cover of 60%, Banksia marginata leaf litter cover of 5-10% and a soil water content of 6-8 VWC were favourable to establishment. These results provide key factors that should be considered when choosing future re-introduction sites and during the management of existing C. robinsonii populations.
The works presented in this thesis provide novel insights that advance the field of orchid conservation in Australia and the world. The current re-introduction methods for C. robinsonii and C. amoena have not been successful at establishing self-sustaining populations. Our new understanding of re-introduced C. robinsonii populations in situ has led to improved in-vitro germination (increases up to 37% in plant numbers for re-introduction) and new on-ground management tools which could greatly improve the chances of halting population declines. Furthermore, this research could be transferrable to other Caladenia species and potentially other orchid genera.</p
Play to Preserve the Past: Design Considerations for the Transmission of Intangible Heritage through Augmented Reality
No full textIntangible heritage, globally, is under threat from aggressive urbanisation and globalisation, particularly in developing nations like Vietnam. To safeguard Vietnamese oral traditions, social practices, festive events and childhood play,the project Play to Preserve the Past uses augmented reality (AR) to undertake a nuanced exploration of creative practice methodologies and considerations for crafting immersive AR experiences. Central to this pursuit, the research endeavours to respond to a pivotal inquiry: "How can creative practitioners harness the potentials of AR for seamless transmission of intangible cultural heritage?” This pursuit has yielded a set of tailored AR game design considerations, including updating heritage aesthetics, physically involving the body in ritual movements, reconfiguring home space into ritual space, and embodying the evolving nature of
knowledge and value systems. These considerations aim to provide nuance and contribute to the discourse by illustrating design steps and reflecting on them. Overall, the intention is to assist future creative practitioners in the field of cultural heritage preservation.</p
How is tailored implementation undertaken using a self-guided toolkit? Qualitative study of the ItFits-toolkit in the ImpleMentAll project
No full textBackground: The process of tailored implementation is ill-defined and under-explored. The ItFits-toolkit was developed and subsequently tested as a self-guided online platform to facilitate implementation of tailored strategies for internet-based cognitive behavioural therapy (iCBT) services. In ImpleMentAll, ItFits-toolkit had a small but positive effect on the primary outcome of iCBT normalisation. This paper investigates, from a qualitative perspective, how implementation teams developed and undertook tailored implementation using the toolkit within the trial.Methods: Implementation teams in thirteen sites from nine countries (Europe and Australia) used the ItFits-toolkit for six months minimum, consistent with the trial protocol. A qualitative process evaluation was conducted. Descriptive data regarding goals, barriers, strategies, and implementation plans collected within the toolkit informed qualitative data collection in real time. Qualitative data included remote longitudinal interviews (n = 55) with implementation team members (n = 30) and observations of support calls (n = 19) with study sites. Qualitative data were analysed thematically, using a team-based approach.Results: Implementation teams developed and executed tailored implementation projects across all steps in the toolkit process. Working in a structured way but with room for flexibility, decisions were shaped by team members’ ideas and goals, iterative stakeholder engagement, internal and external influences, and the context of the ImpleMentAll project. Although teams reported some positive impacts of their projects, ‘time’, both for undertaking the work, and for seeing project impacts, was described as a key factor in decisions about implementation strategies and assessments of success.Conclusion: This study responds directly to McHugh et al.’s (2022) call for empirical description of what implementation tailoring looks like in action, in service settings. Self-guided facilitation of tailored implementation enables implementers in service settings to undertake tailoring within their organisations. Implementation tailoring takes considerable time and involves detailed work but can be supported through the provision of implementation science informed guidance and materials, iterative and ongoing stakeholder engagement, and working reflectively in response to external influencing factors. Directions for advancement of tailored implementation are suggested.</p
Utilizing large language models in infectious disease transmission modelling for public health preparedness
No full textIntroductionOpenAI's ChatGPT, a Large Language Model (LLM), is a powerful tool across domains, designed for text and code generation, fostering collaboration, especially in public health. Investigating the role of this advanced LLM chatbot in assisting public health practitioners in shaping disease transmission models to inform infection control strategies, marks a new era in infectious disease epidemiology research. This study used a case study to illustrate how ChatGPT collaborates with a public health practitioner in co-designing a mathematical transmission model.MethodsUsing natural conversation, the practitioner initiated a dialogue involving an iterative process of code generation, refinement, and debugging with ChatGPT to develop a model to fit 10 days of prevalence data to estimate two key epidemiological parameters: i) basic reproductive number (Ro) and ii) final epidemic size. Verification and validation processes are conducted to ensure the accuracy and functionality of the final model.ResultsChatGPT developed a validated transmission model which replicated the epidemic curve and gave estimates of Ro of 4.19 (95 % CI: 4.13- 4.26) and a final epidemic size of 98.3 % of the population within 60 days. It highlighted the advantages of using maximum likelihood estimation with Poisson distribution over least squares method.ConclusionIntegration of LLM in medical research accelerates model development, reducing technical barriers for health practitioners, democratizing access to advanced modeling and potentially enhancing pandemic preparedness globally, particularly in resource-constrained populations.</p
Are grand tree planting initiatives meeting expectations in mitigating urban overheating during heat waves?
No full textNumerous cities undertakes substantial tree planting initiatives for heatwave mitigation, driven by model predictions indicating a positive mitigation impact. However, emerging studies suggest that the transpiration behavior of trees during heatwaves significantly deviates from normal. This divergence, overlooked in current climate models, introduces the possibility of inaccuracies in predicting transpiration cooling during heatwaves. In this research, 1) The universality of changed transpiration in heat wave is revealed: the study of over 700 trees of various species indicates that the transpiration of at least 65 % of the sampled trees is overestimated by conventional model during heat waves. 2) The transpiration scheme within climate model is revised to represent the new pattern. Comparison shows that conventional model overestimates the peak hour cooling efficiency of trees in heatwave by 60 %. Consequently, the effectiveness of large-scale tree-planting as a heatwave mitigation strategy may not meet expectations, emphasizing the need for strategy refinement during heatwaves.</p
Vietnamese Cinema in the Global Context: A Critical Analysis of Film Genres, Adaptations and Representations
No full textVietnamese cinema has recently achieved success due to its popular appeal. Urban residents, defined as people living in cities or large urban areas, have a lifestyle and mindset distinct from those in the countryside. Vietnamese filmmakers adeptly capture the daily activities, emotions, conflicts, and aspirations of urbanities in modern settings, incorporating these elements into their films. Several films have won national and international awards, and Vietnam has also become a sought-after destination for many foreign film productions.</p
Binary wax oleogels: Improving physical properties and oxidation stability through substitution of carnauba wax with beeswax
No full textHigh concentrations of carnauba waxes (CRWs) that can compromise organoleptic properties are required to create self-sustained and functional oleogels. The weak physical properties and stability of 4% w/w CRW-rice bran oil (RBO) oleogel were addressed by substituting CRW with beeswax (BW) in different weight ratios. The texture profile analyzer revealed that substituting only 10% (weight ratio) of CRW with BW improved the hardness compared to the mono-CRW oleogel. The hardness of binary oleogels increased gradually as the proportion of BW increased. At a BW ratio of 70% or more, the hardness was three times higher than that of mono-BW oleogel. Rheology analysis showed the same trend as the large deformation test; however, the hardest binary oleogels had lower critical strain and yield point compared to the mono-wax oleogels, implying that they are more prone to lose their structure upon applied stress. Nevertheless, nearly all binary mixtures (except for 10%BW90%CRW) showed oil-binding capacities above 99%, suggesting improved nucleation and crystallization process. Polarized light microscopy showed the coexistence of BW and CRW crystals and changes in the size and arrangement of wax crystals upon proportional changes of the two waxes. X-ray diffraction confirmed no differences in the peaks' location, and all oleogels had β' polymorphism. Differential scanning calorimetry showed eutectic melting behavior in some binary blends. Oxidation stability in the binary wax oleogels improved as compared to the mono-wax oleogel and bulk RBO. BW and CRW mixtures have promising oil-structuring abilities and have various properties at different ratios that have the potential to be used as solid fat substitutes. PRACTICAL APPLICATION: As a trending green oil-structuring technology, oleogelation has shown great potential to reduce saturated fats in food systems. The current research provides valuable fundamental information on the strong synergistic interactions between beeswax and carnauba wax that have the potential to be used as solid fat substitutes created with a much lower total concentration of the required wax. This will help create wax oleogels with better organoleptic properties and less negative waxy mouthfeel. Such knowledge could prove beneficial for the development of healthy products that have potential applications in meat, bakery, dairy, pharmaceutical, as well as cosmetic industries.</p
3D Vision and Digital Twin for In-process Geometric Deviation Mapping and Defect Monitoring in Near-net Shape Metal Additive Manufacturing
No full textCold spray additive manufacturing (CSAM) is a solid-state manufacturing technique that offers many possibilities for manufacturing complex free-form metallic parts with a high deposition rate. As a melt-less technology, it minimises oxidation and deposits solid-state coatings while maintaining the original properties of the feed material. CSAM is increasingly employed in aerospace, automotive, healthcare, and defence industries, where structural integrity and functionality are critical. CSAM technology, despite its advantages, is not fully matured. It faces significant challenges related to the geometric accuracy of components and issues with quality and consistency in production.
Moreover, the complex feeding mechanism makes the process unstoppable once it is started. In the current process, system parameters are optimised by several trial-and-error experiments to estimate process parameters. However, they are material-specific, requiring repeated experiments for each material. In addition, the variability in processing parameters leads to defects such as overbuild and underbuild. More importantly, they are amplified in each layer, leading to part failure, causing significant waste of expensive raw materials and increasing overall processing costs. Addressing these challenges requires an uninterrupted in-process monitoring system providing real-time metrology and defect detection capabilities. To address these challenges, this thesis aims to develop and calibrate a three-dimensional (3D) vision system for real-time metrology, generate a digital twin of the printed part and detect geometric defects during the additive manufacturing (AM) process to ensure the dimensional accuracy of the component.
A multi-sensor 3D vision system was developed as real-time metrology equipment for the CSAM process. This setup provides various benefits over using a single scanner. By strategically positioning the scanners, the blind spot in the sensor's Field Of View (FOV) is minimised, allowing for continuous capture of parts as they are constructed. To accurately combine data from the scanners and create a comprehensive 3D point cloud of the developing object, it is crucial to determine the relative transformation between the scanner frame and the robot's end-effector frame (where the plate is mounted). A novel automated hand-eye calibration technique was developed to establish this transformation relationship between the robot and each sensor. The method is efficient, requires no specialised knowledge, and can be conducted by non-expert operators.
The developed 3D scanning system was employed to collect real-time profile data during the CSAM process and mapped into the global coordinate system using the hand-eye calibration result. However, the raw data collected during deposition contains dense, redundant, incremental points representing each single-track deposition. A novel geometric digital twin framework, geometric digital twin in additive manufacturing (gDT-AM), was developed for high deposition rate robotic additive manufacturing (HDRRAM). It continuously captures and maps the part's geometry in real-time during printing. It includes two experimentally validated alternative techniques for quickly and accurately reconstructing surfaces from sparse spatio-temporal two-dimensional (2D) line profiler scans.
The gDT-AM framework was further enhanced by integrating a geometric deviation detection system. The deviation detection system leverages a reference model representing near-net manufactured components without sharp edges. A 3D deviation map was generated by comparing the reference model with the part digital twin model. The system also tracks the shape and size of the segmented local deviations layer by layer. A streamlined pipeline for real-time 3D reconstruction of the growing part and direct quantitative comparison with reference near-net model enables the identification of potential defects during production, facilitating timely interventions that reduce waste and ensure quality.
Experiments were conducted on various complex CSAM builds to evaluate the efficacy of the proposed defect detection system. The defect data and toolpath information were correlated to identify patterns and conditions where defects occurred, closing the gap in the literature. The findings underscored the potential of a laser scanning system for defect detection and its importance in CSAM process control for the geometric accuracy of parts.</p
Into the Archives
No full textPresented as a reflective article and visual essay, this article delves into co-existing narratives emerging from fashion and textiles collections in the RMIT Design Archive: advancing technologies and changing industry, shifting cultural influences and approaches, and design thinking through material practice. Emerging from textile print and dye swatches in the Frances Burke, Michael O’Connell and Linda Jackson collections, these narratives contribute to the broader contextualisation of materials, practices and designers in the archive and form a dynamic picture of the evolution of fashion and textiles practices in Melbourne, Australia from the mid-twentieth century.
As well as drawing out these narratives, approaches for engaging fashion and textiles students from diverse disciplines with material culture in archival collections are shared. Looking to workshops run through the RMIT foundation course, ‘Fashion, Textiles, Place and Story’, three factors are identified to increase student access to archival spaces: scholarship and research of collection holdings to underpin learning experiences in archives; time dedicated to facilitation, guidance, interpretation and exploration of collections in archival spaces; compelling storytelling and a call to action that encourages further curiosity and investigation.
Integrating photographs of items in RMIT’s design archive which not have not previously been documented and published, this article expands access to the nationally significant holdings, and highlights the collection’s value for material-culture studies, fashion and textiles design, research and teaching.</p