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Catalytic activation of liquid gallium by discretely dispersed copper atoms
No full textDespite the rising use of liquid metal alloys in catalytic applications, the nature of synergistic effects between constituent metals which are central to achieving enhanced reactivity, remains unclear. Herein, we report the synthesis of liquid metal alloys consisting of discretely dispersed Cu in the eutectic gallium-indium alloy EGaIn and investigate the role Cu plays in the activation of Ga. The performance of Cu-based liquid metal alloys was assessed for the synthesis of solketal and in situ hydrogen generation applications. Molecular dynamics simulations combined with experimental investigation indicated that the activation of Ga atoms by adjacent Cu atoms is responsible for the observed enhanced activity of the Cu-EGaIn alloy. This research clarifies the role dissolved metallic species play in liquid metal catalysis and also highlights opportunities for the use of liquid metals as reducing agents in organic synthesis and in situ hydrogen generation applications
Psychological distress in older adults: associations with epigenetic markers of ageing, inflammation, and depression, and joint effects on mortality
No full textBackground: Psychological distress is associated with adverse health outcomes. We aimed to assess whether the health impacts of psychological distress could be captured by epigenetic markers of ageing, inflammation, and depression, and whether these markers and psychological distress have a synergistic association with mortality in older Australians. Methods: Blood DNA methylation data for 1146 participants (31 % females, mean age: 69 years) in the Melbourne Collaborative Cohort Study were used to calculate epigenetic markers of ageing (PCPhenoAge, PCGrimAge, bAge, DunedinPACE) and inflammation (C-reactive protein [mCRP]), and two methylation scores for depression. Psychological distress was assessed by the Kessler scale (K10). Linear regression was used to assess the associations of K10 with epigenetic markers. Cox models were used to assess the multiplicative and additive interactions of K10 and epigenetic markers in their association with all-cause mortality. Results: We observed positive associations of K10 with epigenetic markers of ageing and inflammation: per standard deviation (SD), 0.05 (95 %CI: 0.00–0.11) for DunedinPACE to 0.10 (95 %CI: 0.05–0.16) for PCPhenoAge. Associations of epigenetic markers of ageing with mortality were stronger in participants with higher psychological distress. The relative excess risk due to interaction for DunedinPACE was 0.82, 95 %CI: 0.14–1.50. Conclusion: In older Australians, higher psychological distress was associated with older epigenetic age and higher mCRP. Participants with higher levels of both psychological distress and epigenetic markers of ageing and mCRP had higher mortality risk. These findings highlight links between psychological and biological health, and the potential importance of considering both for disease risk stratification
Queer labour in the Melbourne hospitality industry
No full textFront of house hospitality workers are tasked with a multitude of expectations to provide pleasurable consumption experiences through the course of their labour. In hospitality venues across Melbourne, Australia, workers must orient themselves towards a venue’s vibe—a cumulative affect of consumption offering, aesthetics, branding and location. In Melbourne, known as Australia’s ‘heart of culture’, hospitality venues are increasingly marketing themselves as spaces of tolerance and inclusivity. Yet, the labour that produces these spaces has gone largely unaccounted for in research about the dynamics of the service industry. In this study, I explore the contours of service labour performed by queer front of house hospitality workers to reveal how inclusion is cultivated through the bodies of workers themselves. This article maps the modes of labour that queer hospitality workers are expected to perform at work, the types of queer expression that are celebrated, tolerated, encouraged and rebuked in the workplace, and the additional demands placed on queer workers when venues market themselves as inclusive spaces. Through interviews with 20 queer, front of house hospitality workers across Melbourne’s hospitality sector, this research finds that theories of affective, aesthetic and emotional labour can be expanded by incorporating the spatial dimensions of work that are uniquely queer. As such, I argue that queer workers produce diversity capital in the form of economic and social value for venues aiming to cater to a socially conscious consumer-base through the enrolment of their queer biographies into the labour they perform
3D printing of TPMS microlattice: indentation characterisation and numerical analysis
No full textMechanical metamaterials are emerging as an important tool in many engineering applications, where microarchitectured lattices have advantages of high strength-to-weight ratios, energy absorption capabilities and versatility in designed mechanical behaviours. Whilst a variety of microarchitectured lattices have been previously investigated for their mechanical properties, they have been mostly constrained to strut and plate-based designs and subjected to additional post-processing to modify their functionality. In this work, we demonstrate a novel approach utilising the two-photon polymerisation (2PP) method to generate complex, defect-free microarchitectured lattices. Unlike traditional methods, our technique allows for the direct fabrication of shell-based triply periodic minimal surfaces (TPMS) without requiring any additional post-processing. We utilise gyroid and diamond TPMS unit cells to perform uniaxial micro-compression testing to characterise their mechanical properties. In doing so, we gain insights into the mechanical behaviours of microlattices, with the finding that diamond cells possess superior stiffness and energy absorption potential compared to gyroid cells. To unravel the size-dependency property alterations at this scale, we further analyse a variety of bending beam samples and observed a strain rate-dependent mechanical behaviour attributable to the material's viscoelastic nature. We employ finite element analysis to enhance our understanding of the deformation mechanisms inherent in TPMS topologies, finding good agreement with measured mechanical properties. This work establishes a comprehensive framework that spans from design and geometry characterisation to robust microstructure testing using indentation, combined with comprehensive numerical simulation
A Prototype Rapid Tool to Enhance Detection of Dementia for Aboriginal and Torres Strait Islander Peoples in Primary Care
No full textINTRODUCTION: Dementia is prevalent within Aboriginal and Torres Strait Islander communities but clients attending primary care often remain undiagnosed. This project aimed to develop a rapid dementia screen for primary care. METHODS: Logistic regression was used to identify candidate items from the Kimberley Indigenous Cognitive Assessment (KICA-Cog). The psychometric properties of different scales were assessed using receiver operating characteristic curve analysis and validated in a separate cohort. RESULTS: Four items in the KICA-Cog demonstrated high sensitivity (82.6%), specificity (83.2%) and area under the curve (AUC = 0.90; 95% CI: 0.87-0.94) for dementia at a cut-off point of 7/8 out of 10. This scale has favourable psychometrics (sensitivity 87.5%, specificity 80.9%, AUC = 0.92; 95% CI: 0.85-0.98) when validated in separate cohort. DISCUSSION: The proposed prototype tool, ready for community piloting and validation, may be useful in primary care to enable rapid cognitive screening as part of routine health care
Flocculation-flotation of ultrafine hematite from quartz using anionic polyacrylamide as a selective flocculant
No full textConventional flotation cells are widely used for concentrating iron ores, yet one major challenge remains – the low recovery rate of ultrafine particles, particularly when processing low-grade deposits. This study explores the application of anionic polyacrylamide (APAM) in hematite and quartz mixtures (D50: 1 μm, feed grade: 27.2 % hematite) to selectively aggregate hematite for enhanced flotation recovery. The role of sodium hexametaphosphate (SHMP) was examined as a dispersant to prevent heterocoagulation and to enhance selective aggregation towards hematite, evaluating its effect on the combined flocculation-flotation performance. Detailed insights are provided into the interactions between each reagent combination with sodium oleate (NaOL) as collector, along with an analysis of the limitations of this approach. Flotation with NaOL alone resulted in a hematite recovery of 44.5%. The addition of APAM increased hematite recovery to 82.7%. There was limited improvement in grade due to increased quartz entrainment and entrapment within the aggregates. When combined with SHMP, hematite grade improved by 11.4% as SHMP reduced heterocoagulation between hematite and quartz, and reduced entrainment by regulating the froth. Over 99% hematite recovery was achievable with optimised reagent doses. Since SHMP also functions as a depressant, the dose must be optimised to avoid excessive froth destabilisation. Overdosing APAM resulted in overly hydrophilic flocs which negatively impacts recovery. Balancing the dosage of all three reagents is crucial for optimum results. The highest grade achievable was 45.2% due to quartz entrapment and entrainment which is difficult to minimise in conventional lab scale mechanical flotation cells when handling ultrafine minerals
Integrated Disease Management, Adaptation and Genomics of Fungal Plant Pathogens in Cropping Systems
No full textABSTRACT
Crop production systems contribute significantly to maintaining global food security. These systems often involve the cultivation of single cultivars in highly homogenised environments to meet demands. Agriculturally important plant fungal pathogens can be destructive constraints in such systems. Integrated disease management strategies comprising the tactical use of cultural, chemical and host genetic controls are deployed to reduce the impact of plant pathogens. The homogenous nature of these cropping systems combined with evolutionary forces on the often‐flexible fungal genome increases the potential for rapid adaptation of plant pathogens to current integrated disease management practices. This review explores the genomic features of the fungal genome (such as transposable elements and copy number variation) that influence the adaptation of pathogen populations in cropping systems. Furthermore, the interactions between such genomic features and the evolutionary forces that drive fungal adaptation are discussed relative to the three major components of integrated disease management in agricultural systems. This review specifies the need for a cohesive analysis of fungal plant pathogens within cropping systems to maintain sustainable food production in the face of future pathogen adaptation and evolution
Cultural adaptation of the Mental Health Support Scale for Chile and Argentina
No full textThis study aimed to adapt and validate the Mental Health Support Scale (MHSS) for Chile and Argentina, hypothesising that it would correlate positively with mental health literacy, negatively with stigma measures, and differ by mental health first aid (MHFA) training history. The MHSS involves the ‘Intended’ scale (assessing intended support) and the ‘Provided’ scale (evaluating actual help), capturing recommended and not-recommended actions. The scales were translated into Spanish, piloted with 17 adults to explore cultural relevance, and validated with 554 Chilean and Argentinian adults using concurrent measures of stigma, social distance and mental health literacy. Factor analysis of the MHSS-Intended identified a recommended factor (16 items) and a not-recommended factor (5 items). The recommended factor correlated positively with mental health literacy (r = 0.19) and negatively with weak-not-sick stigma (r = -0.16) and social distance (r = -0.16). Support scores significantly discriminated between participants with and without MHFA training (recommended d = 0.99, not-recommended d = 1.35) and within participants pre- and post-MHFA training (recommended d = 0.90, not recommend d = 0.47). Overall, the adapted MHSS demonstrates acceptable psychometric properties and is a promising tool for evaluating mental health first aid support in Chile and Argentina
The everyday lives of gig workers in Melbourne
No full textThe rise of the gig or platform economy, particularly app-based food delivery platforms, has transformed urban labor markets and the everyday geography of work. While gig work is often celebrated for its flexibility, little is known about how gig workers, especially food delivery riders, experience various forms of spatial and institutional exclusion in their efforts to access restaurants and customers’ premises. Within this context, drawing on interview data with 17 food delivery riders and participant-produced photographs, this paper explores the relationship between gig workers’ everyday lives and gig work in Melbourne. Our findings demonstrate that food delivery riders often experience various forms of exclusion while collecting food from restaurants and delivering it to customers. In addition, workers often have to rest on their bikes or public benches as they do not have any designated resting areas. Despite these challenges, our findings show that food delivery riders are able to use urban public spaces to create social networks, which is beneficial to their mental wellbeing
Formalized Burrows-Wheeler Transform
No full textThe Burrows-Wheeler transform (BWT) is an invertible lossless transformation that permutes input sequences into alternate sequences of the same length that frequently contain long localized regions that involve clusters consisting of just a few distinct symbols, and sometimes also include long runs of same-symbol repetitions. As a consequence, the BWT is used in a wide range of tools, from everyday file compression software, such as bzip2, to highly sophisticated bioinformatics tools, such as DNA sequencers, where an efficient encoding of genomic sequences is essential. As such, ensuring the correctness of the BWT is critical. In this paper, we present the first formal verification of both the BWT and its inverse. Our verification efforts are conducted in Isabelle/HOL. Building on a recent formalization of the suffix array construction algorithm, we provide a mechanized proof of correctness, invertibility, and termination for both transformations. By doing so, we address the gap in the formal verification of compression algorithms, ensuring that the BWT can be safely deployed in critical applications such as genomic data analysis. This work thereby also provides the necessary foundation for verifying the various algorithms for compression and text search that operate on BWT-transformed sequences