University of South Australia

This research experimentally and numerically investigates the feasibility of using low-cost timber plates to enhance the shear behavior of reinforced concrete (RC) beams. Seven simply supported beams with a shear span-to-depth ratio (a/d) of 1.8 were tested under three-point bending, including one control specimen and six strengthened beams. Two strengthening techniques, externally bonded (EB) and near-surface mounted (NSM), were examined using three attachment methods: epoxy only, 10 mm diameter anchor bolts only, and a combination of both. A 3D finite element model (FEM) was developed in ABAQUS V2017 to evaluate the influence of increasing the a/d ratio from 1.8 to 3.1 on the ultimate load, stiffness, and toughness of the strengthened beams. results showed that timber plates, regardless of the strengthening technique, effectively restricted the propagation of the main shear crack and diverted it into multiple secondary cracks. Externally bonded specimens achieved higher ultimate loads than NSM specimens due to the absence of groove-induced reductions in the concrete section. The use of anchor bolts, either alone or in combination with epoxy, prevented debonding and produced the highest ultimate loads, reaching 91 kN and 92 kN, respectively, representing increases of 21.3 % and 22.7 % over the control beam. Both attachment methods also exhibited stiffness improvements of 10.8 % compared to the control beam. Numerical analysis indicated that increasing the a/d ratio from 1.8 to 3.1 led to reductions in stiffness of 43 %-47 %, ultimate load of 18 %-30 %, and toughness of 7 %-30 %. • The shear behavior of RC beams strengthened with timber plates was investigated. • Two strengthening techniques were considered: external strengthening and NSM technique. • Three different attaching methods were used: epoxy alone, anchor bolts alone, or a combination of both. • A Finite element model was developed to examine the effect of the shear span-to-depth ratio. • Using anchor bolts alone or in combination with epoxy exhibited the highest ultimate load.

A promising short-form tool for screening mental health in children is the Patient Health Questionnaire (PHQ-4) which contains two items each assessing anxiety and depression. Despite its emerging use, the construct validity of the PHQ-4 remains to be fully established in children and especially in pre-adolescent children as does its convergent validity. Children completed an online survey containing demographic and PHQ-4 items during school time in 2024 to 88,587 pre-adolescent (7-11y: 48% F, 49% M, 3% Minority Gender (MG)), 66,561 early adolescent (12-14y: 50% F, 47% M, 3% MG), and 36,731 late adolescent (15-18y: 53%F, 44% M, 3% MG) Australian children. In each age by gender identity groupings, dimensionality was tested using exploratory/confirmatory factor analyses (EFA/CFA) and exploratory graph analysis (EGA). Convergent validity was tested with Life Satisfaction Score and Child Hope Scale (CHS). PHQ-4 scores increased with age (Pre-<Early < Late Adolescent) and were higher in minority versus cisgender children (Male < Female < MG). EGA revealed that the PHQ-4 was unidimensional while CFA revealed a bidimensional model fit. PHQ-4 was moderately correlated with Life Satisfaction and CHS. Given the limitations of latent variable analysis when scale length is constrained, it is suggested that the PHQ-4 is best regarded as a brief unidimensional scale for screening general mental health in Australian children.

Neodymium isotope ratios have unique characteristics for tracking the movement and origins of marine animals. However, neodymium (Nd) is present in low concentrations in seawater and marine animal tissues, which can make isotopic analysis challenging. Previous research on Nd isotope ratios in marine animals has been restricted to bivalves, with limited details regarding sample preparation and variations in Nd concentrations. We tested five hot plate-based acid digestion methods on six marine animal classes (Actinopterygii, Thecostraca, Malacostraca, Cephalopoda, Bivalve, Holothuroidea) and nine tissue types (soft and hard tissue), with Nd concentrations measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Nd concentrations obtained in this study were also compared to other published data across marine taxa. Nd was successfully extracted from all animal samples except for fish otolith, bone, and muscle which had very low levels of Nd. Concentrated HNO3, 8M HNO3 and 50% Reverse Aqua Regia were the most effective acid treatments overall. Nd concentration varied widely among taxa, tissue types, and individuals, ranging from less than 1ng/g to 370ng/g in our samples, and less than 100ng/g in the published literature. Our results suggest that Nd isotope analysis could have wide-ranging applications to many taxa but may not be feasible for some taxa or tissue types with very low Nd concentrations. We also recommend testing Nd concentrations before pursuing isotopic analyses. We hope to encourage further exploration of the use of neodymium isotopes for tracking movement, connectivity and provenance of marine animals.

Grinding environment strongly influences chalcopyrite surface reactivity and flotation, but direct dry-wet comparisons are often confounded by size and liberation effects. This study presents a mechanistically controlled comparison of dry and wet grinding effects on chalcopyrite by achieving closely matched particle size distributions and comparable liberation for both a model mineral and a low-grade copper ore. Under these controlled conditions, pronounced differences in surface chemistry and electrochemical reactivity were observed. Dry-ground particles exhibited higher oxygen demand, indicating highly reactive, minimally passivated surfaces, whereas wet-ground particles showed greater surface oxidation, which intensified with increasing temperature due to galvanic interactions and oxyhydroxide formation. These surface modifications directly translated into flotation behaviour: dry grinding consistently yielded higher copper recoveries and grades, while wet grinding particularly at elevated temperatures led to reduced collector adsorption and flotation performance. Grinding additives had negligible effects on the model mineral and only modestly improved recovery in the real ore, without altering dominant oxidation trends. Overall, the results demonstrate that, under equivalent liberation conditions, chalcopyrite flotation performance is governed primarily by grinding-induced surface chemistry rather than bulk mineral exposure. • Bulk surface chalcopyrite liberation is similar under both grinding environment. • Dry grinding forms reactive surfaces; wet grinding reduces reactivity at all T, GA negligible. • Flotation efficiency is governed by surface chemistry under comparable liberation.

This study examined whether socio-economic status (SES) and geographic remoteness are associated with cannabis consumption across Australia by comparing wastewater-based surveillance (WBS) data and self-reported cannabis use in national household surveys. We compared cannabis consumption estimates from 6years of wastewater data from the National Wastewater Drug Monitoring Program (NWDMP) with cannabis use data from the National Drug Strategy Household Survey (NDSHS). We categorised the Index of Relative Socio-economic Advantage and Disadvantage (IRSAD) into quartiles for each wastewater catchment area. Three remoteness categories (Major Cities, Inner Regional, Outer Regional/Remote) from the Australian Bureau of Statistics were used to categorise wastewater and survey data by degree of urbanisation. Trends were analysed using linear regression, analysis of variance and logistic regression. Wastewater: Estimated cannabis consumption in wastewater increased between 2018 and 2025 annually across SES quartiles from 2.9% [95% confidence interval (CI) = 2.0-3.9%] for the most disadvantaged to 5.2% (95% CI = 3.2-7.3%) for the second most disadvantaged quartile. The annual rates increased for all three categories of remoteness and ranged from 3.6% (95% CI = 2.2-5.2%) to 4.8% (95% CI = 4.2-5.5%) for Inner Regional and Major Cities, respectively. Consumption was statistically significantly higher in the most disadvantaged SES quartile (3000 mg/1000 people/day, 95% CI = 2900-3100) than in the least disadvantaged (1200 mg/1000 people/day, 95% CI = 1100-1200, P < 0.001). It was also highest in the most remote category (2400 mg/1000 people/day, 95% CI = 2300-2500), compared with the most urban category (980 mg/1000 people/day, 95% CI = 960-1000,P < 0.001). In the NDSHS the prevalence of regular cannabis use was higher in the most disadvantaged SES quintile (6.1%, 95% CI = 5.2-7.3% in 2022/2023) than in the least disadvantaged (4.2%, 95% CI = 3.5-5.1% in 2022/2023). It was also higher in the most remote category (5.9%, 95% CI = 4.8-7.4%) than in the most urban category (4.3%, 95% CI = 3.9-4.8%), in all survey years (i.e. 2016 and 2019). Wastewater-based surveillance and survey data describe similar trends in population cannabis use by socio-economic status and urban remoteness in Australia from 2018 to 2025.

Jack Jumper ant (JJA) venom immunotherapy (VIT) is highly efficacious but the lowest effective dose is unknown. Delta-inulin adjuvant (Advax) is known to enhance honeybee VIT immunogenicity. This phase 1/2 single-blind, randomised controlled trial aimed to compare the efficacy and safety of JJA VIT with different doses of venom ± Advax. Adults aged 18-65 with a history of immediate systemic reaction (SR) to JJA stings were randomised to receive JJA VIT at a maintenance dose of 25 mcg or 50 mcg ± Advax; participants were blinded to treatment allocation. Primary outcomes were the response to sting challenges after 12 months and venom-specific IgE and IgG4 responses to treatment. Forty-nine of 50 screened subjects met inclusion criteria and were randomised; 44 started treatment (25 mcg n = 12; 25 mcg + Advax n = 13; 50mcg n = 12, 50 mcg + Advax n = 12). Subsequently, two withdrew due to SRs to treatment, and two withdrew due to unrelated factors. The higher JJA venom maintenance dose was associated with reduced likelihood of SRs (OR 0.53 (95% CI, 0.28-0.98)), while Advax did not have an effect (OR 1.17 (95% CI, 0.59-2.32)). Forty proceeded to sting challenge, with six developing SRs. There was no difference between groups for sting challenge outcome (p = 0.98), and the ORs for 25 mcg vs. 50 mcg venom dose (0.89, 95% CI, 0.38-2.09) and Advax vs. no Advax (0.99, 95% CI 0.42-2.33) indicated no effect. There were no differences between groups for venom sIgE (p = 0.78), sIgG4 (p = 0.25), sIgE/IgG4 ratio (p = 0.42), intradermal (p = 0.77), and basophil activation test (BAT) (p = 0.69) responses to treatment. Subjects with high baseline BAT sensitivity, which reduced markedly in response to treatment, were less likely to have a positive sting challenge (p = 0.006). Challenge outcomes were similar for all groups, with no significant difference found between 25 and 50 mcg maintenance dose or between treatment with and without Advax. Further research of low dose JJA VIT is warranted to confirm its efficacy and tolerability. NCT03066986.

Objectives: To determine the impact of discharge home on physical activity and sedentary behaviour following orthopaedic trauma. Design: Observational study. Setting: Acute hospital. Participants: Between October 2022 and January 2024, 31 adult orthopaedic trauma patients were recruited during hospital admission. Participants had either an isolated hip fracture or multi-trauma (i.e., a lower limb fracture, with an upper limb and/or spinal fracture). Interventions: Participants wore two activity monitors (activPAL3 and ActiGraphGT3x) during the final days of an acute hospital admission and the first five days at home. An interrupted time series analysis evaluated changes physical activity variables during the hospital to home transition. Participants were analysed individually using mixed-effects linear regression allowing the intercept to vary by participant. Main outcome measures: Primary outcome was daily steps; secondary outcomes included sedentary time and other activity measures. Results: Daily steps (mean +- SD) were higher at home (4552.4 +- 2639.5) compared to hospital (2597.8 +- 1450.8). Modelled results indicated a 27% increase in daily steps following hospital discharge (exp(beta946;): 1.27, 95% CI: 1.01,1.59, p=0.039) and a sustained improvement at home. No significant differences were observed between hip fracture and multi-trauma participants. Conclusion: Participants recovering from orthopaedic trauma showed a significant increase in daily step count upon discharge home from hospital, highlighting the positive impact of the home environment on activity levels. Further research is warranted to assess the effectiveness of interventions to improve activity levels in hospital (e.g., early intensive therapy) and at home (e.g., immediate home-based physiotherapy) in individuals following orthopaedic trauma.

Prostate cancer progression is characterized by dysregulated lipid metabolism, with fatty acid synthase (FASN), the rate-limiting step in de novo lipogenesis (DNL), resulting in significant accumulation of saturated lipids. Here, we investigate whether pharmacologic FASN inhibition creates a metabolic state that increases reliance on exogenous polyunsaturated fatty acids (PUFAs). Inhibition of FASN profoundly alters membrane phospholipid composition, driving compensatory incorporation of PUFAs into membrane phospholipids, thus increasing susceptibility to lipid peroxidation and oxidative damage. Combined FASN inhibition and PUFA exposure increased reactive oxygen species, induced mitochondrial hyperpolarization, and enhanced lipid peroxidation in both hormone-sensitive and castration-resistant prostate cancer models. Marked inhibition of human and murine prostate cancer organoids is achieved ex vivo . In genetically engineered, DNL-reliant Hi-Myc mice, a diet enriched in PUFAs significantly inhibited invasive carcinoma compared to a saturated fat-enriched diet. Environmental PUFAs modulate and enhance the therapeutic efficacy of FASN-targeted strategies. These findings set the stage for pharmacologic and dietary intervention in prostate cancer patients.