134125 research outputs found
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Asymmetric return–volatility relationship of uranium investments
No full textThis study investigates the return–volatility relationship of the largest physical uranium investment trust, Sprott Physical Uranium Trust (SPUT), addressing a largely underexplored asset class. Analyses based on daily data yield mixed results. However, when accounting for the persistence of volatility using intraday data, a classical equity-like asymmetrical relationship emerges, consistent with SPUT's nature as an investment vehicle. Notably, during periods of extreme volatility, positive shocks appear to have a more pronounced impact. These findings suggest that the return–volatility relationship is not uniform across the return distribution.Full Tex
Getting to 'Yes!': Reflections on "Shimmer" (Book review)
No full text1 INTRODUCTION: A “CO-BECOMING OF MUTUAL DELIGHT” (ROSE, 2022, P. 140)
Whether or not you have engaged with Deborah Bird Rose previously, we can attest that her final book, Shimmer: Flying fox exuberance in worlds of peril (2022 [2018]) will win and break your heart; and in so doing will alter your life. The life and death work of exuberance that Rose offers takes up a surprisingly conversational style that corrals academic conventions in rich footnotes so as to offer vital, even visceral, profound and accessible insights for a broad audience. Rose’s posthumously completed work is collaborative storytelling of exuberance, care, ethics, and ethnographies of flying foxes across Australia that we all need to read and bring into our conversations.Full Tex
Profile of paediatric mental health presentations to Australian emergency departments in 2018
No full textObjectives Paediatric mental health presentations to emergency departments (EDs) are rising. Rural/Regional mental health service users face structural barriers to accessing general and specialist treatment, including physical distance and local service capacity and funding constraints. However, differences in patient characteristics and treatment pathways between major city and rural/regional EDs remain unclear. This study aimed to compare demographic and clinical profiles of paediatric mental health patients within each location.
Methods Retrospective cohort study of paediatric (aged 0–17 years) mental health presentations at 23 Australian EDs (metropolitan=18, rural/regional=five) from 1 January to 31 December 2018. At each site, up to 100 randomly selected unique patient medical records were included. Demographic and clinical characteristics were compared using logistic and linear mixed effects regression models.
Results 2234 young people were recruited (metropolitan=1803, rural/regional=431). Mean age was 14.4 years (SD=2.6) and 59.4% were female. Frequent presentation reasons were suicidal ideation (853; 38.2%), self-harm (668; 29.9%) and behavioural disturbance (306; 13.7%). Of those with complete documentation, 703 (70.9%) had family history of mental illness and 933 (41.8%) reported recent interpersonal difficulties (eg, family/peer conflict). Three hundred and twenty-nine young people (14.7%) were admitted and 1024 (45.8%) were referred to public child and adolescent mental health services (CAMHS). Patients in rural/regional settings had shorter median waiting times for ED clinicians (24 vs 42 min) and mental health assessments (1.1 vs 2.5 hours), shorter median ED length of stay (2.9 vs 4 hours) and higher likelihood of referral to CAMHS on discharge (OR 2.19, 95% CI 1.22, 3.93).
Conclusions Characteristics of children and adolescents presenting with mental health concerns are broadly similar between metropolitan and rural/regional EDs, but treatment characteristics differ. Frequency of family mental illness and interpersonal difficulties highlights the benefits of family focused interventions. Given similar patient profiles, equitable resourcing of rural/regional services is warranted.Full Tex
Simulated effects of surgical corrections on bone-implant micromotion and implant stresses in paediatric proximal femoral osteotomy
No full textBackground and objective: Proximal femoral osteotomy (PFO) is a surgical intervention, typically performed on paediatric population, that aims to correct femoral deformities caused by different pathologies (e.g., slipped capital femoral epiphysis). A PFO involves introduction of an implant to fix the proximal and distal sections of femur following the surgical corrections. The femoral neck-shaft angle (NSA) and anteversion angle (AVA) are key geometric parameters that influence PFO outcomes. To date, the effects of NSA and AVA on bone-implant system mechanics in paediatric populations have not been examined. Methods: This study used an established neuromusculoskeletal modelling process paired with finite element analysis to determine the sensitivity of the implanted femur's mechanics to variations in NSA and AVA during the stance phase of walking. Three male patients aged 9–12 years with different pathology (Spastic diplegia, Perthes disease and Slipped Capital Femoral Epiphysis), weight (377, 747, 842 N), height (1.39, 1.55, 1.71 m) and femur lengths (34.1, 39.4, 43.7 cm) and geometries (NSA: 143, 102, 111 deg; AVA: 29, 17, -22 deg) were examined. For each patient, a three-dimensional bone model was created from computed tomography imaging and digital surgical corrections were applied to systematically vary the NSA and AVA. Personalized motion and loading conditions driven from a neuromusculoskeletal modelling process were applied to each model and its associated permutations of NSA and AVA. Results: Results indicated significant intra-participant variability in post-PFO bone-implant micromotion and peak von Mises stress on implant. For models with a post-surgery NSA of 135° and AVA of 12°, the averaged micromotion increased by 87 % and the peak von Mises stress decreased by 63% between patient 1 and 2. Between patient 2 and 3, the averaged micromotion decreased by 55% while the peak von Mises stress increased by 84%. Conclusions: Furthermore, post-PFO bone-implant mechanics were sensitive to variation in NSA and AVA in a subject-specific manner. Optimization of PFO planning is recommended based on patient-specific characteristics.Full Tex
ZnIn2S4 nanosheets grown on biomass chitin-derived 3D carbon substrates as self-supporting high-efficiency photocatalysts for water splitting
No full textThe charge transfer within heterojunctions is a critical factor influencing the overall efficiency and stability of photocatalytic water splitting. In this context, a heterojunction of two-dimensional ZnIn2S4 nanosheets grown on two-dimensional chitin-derived N-doped carbon (Chitin-NC) nanosheets was fabricated, forming an integrated three-dimensional interconnected network architecture of Chitin-NC/ZnIn2S4 composite with visible light response. This well-designed stable structure exposes more catalytic active sites and promotes the separation and migration of photogenerated charges, demonstrating the excellent photocatalytic activity for hydrogen evolution and cyclic stability of the Chitin-NC/ZnIn2S4 composite. Under visible light irradiation, the optimized Chitin-NC/ZnIn2S4 achieved a hydrogen production rate of 0.665 mmol g−1 h−1 without the use of any co-catalysts. And the structure remained stable after multiple photocatalytic cycles. This achievement provides a new cost-effective and sustainable methodology for enhancing the efficiency of photocatalytic water splitting.No Full Tex
Techno-Economic, Predictive Modeling, and Demand Response Analysis of a Renewable Energy-Based Microgrid for Residential Applications
No full textThis study develops a grid-connected solar PV–biogas microgrid for a five-story residential building in Rajshahi, Bangladesh, optimized using HOMER Pro. Among six configurations, the optimal configuration, integrating solar PV and a biogas generator, achieves a 59.4% renewable fraction, reducing CO2 emissions by 46% and lowering the cost of energy to 46,813, with an annual operating cost of $ 1,187. It generates 31,168 kWh/year from solar PV and 3,040 kWh/year from biogas, with grid purchases and sales of 21,951 kWh/year and 13,411 kWh/year, respectively. Predictive modeling ( R2=1.0 ) enhances power estimation accuracy. MATLAB-based stability analysis confirms seamless voltage and frequency integration. A demand response strategy achieves 2,730.44 kWh/year savings, reducing non-renewable reliance. The analysis results show the microgrid’s high reliability, with negligible Energy Not Supplied (ENS) is 4.31×10−14 kWh and an almost zero Loss of Power Supply Probability (LPSP) is 1.06×10−18 , indicating stable and uninterrupted power supply. Sensitivity analysis identifies solar irradiance as the dominant cost factor. The results establish a scalable, cost-effective model for residential renewable microgrid adoption globally.Full Tex
Investigating Patient Preferences for Their Doctor's Communication Strategies Across Cultures Using Communication Accommodation Theory
No full textEffective doctor-patient communication has been linked to better patient outcomes and treatment adherence, whereas ineffective communication has been linked to poorer outcomes and more medical errors. Our study used Communication Accommodation Theory (CAT) to investigate across four countries which communication strategies patients preferred from their doctors. Archival data from a larger online survey research study provided a sample of 1698 participants (Male = 36.4%, Female = 61.1%, Other 1.8%, Age M = 25.5 SD = 10.67), recruited from four countries (Australia, USA, Hong Kong/China, and the Philippines). Results showed participants preferred accommodative stances over non-accommodative stances (under or over accommodation), and that accommodative interpretability was the most frequently mentioned communication strategy in all four countries. Chi-square analyses revealed significant differences across countries for all strategies, with the strongest effects for discourse management. Implications for adding CAT into medical education communication training are discussed.Full Tex
Photo-Piezojunction Coupling Effect in n-3C-SiC/p-Si Heterojunction – A Platform for Self-Powered Strain-Sensing Applications
No full textIt is beneficial to investigate multifunctional self-powered sensors with high sensitivity and energy-scavenging capabilities, which are essential for the development of a smart infrastructure in the era of 5G and Internet of Things (IoT). This paper reports the photo-piezojunction coupling effect, i.e., the coupling of piezojunction effect with photovoltaic effect, in an n-type 3C-SiC/p-type Si heterojunction (n-3C-SiC/p-Si) and demonstrates it through a proof-of-concept self-powered strain-sensing device. The device exhibits superior photon energy-harvesting capability, generating 24.54 mV with a laser power of only 10 μW, approximately five times higher than that of reported devices utilizing the lateral photovoltaic effect, and an exceptionally high strain sensitivity, achieving |(ΔV/V)/ϵ| ratios of 43.14 and 21.34 for tensile and compressive strain, respectively, which are 4.3 times more than that of devices reported in previous studies. The findings of this study significantly advance the understanding of the photo-piezojunction coupling effect in n-3C-SiC/p-Si heterostructures, laying the foundation for the development of multifunctional sensor systems capable of harvesting photon energy.Full Tex
Rock weathering characteristics and carbon sink in the Liujiang Basin, North China
No full textGlobal greenhouse gas emissions are on the rise, exacerbating warming. Rock weathering significantly influences the carbon cycle and climate. There are differences in the consumption of atmospheric CO2 during the weathering process of different rocks. The Liujiang Basin, typical strata from various geological periods in North China, holds significant representative importance in assessing rock weathering and carbon sink. In this regard, we collected two sample series during both high-water and low-water periods and assessed the chemical weathering rates based on the chemical and isotopic compositions of the water, as well as a forward modeling strategy which is based on mass balance. The forward modeling analysis illustrated that rock weathering contributed the most to the total cations (81.62 %–97.13 %, with an average of 92.89 %), with carbonate rock weathering contributing the most (23.80 %–77.12 %, with an average of 54.61 %), followed by silicate rock weathering (3.27 %–61.19 %, with an average of 21.17 %) and evaporite dissolution (5.93 %–26.52 %, with an average of 17.11 %). The Sr concentrations in the river water ranged from 0.63 to 21.34 μmol L−1, while Sr isotope ratios (87Sr/86Sr) had a 101 % variation scale. The δ13C values ranged from −14.73 to −7.06 ‰. Quantitative analysis further illustrated that atmospheric precipitation, carbonate, and evaporite inputs collectively accounted for 64.15 % (42.12 %–97.61 %) of total dissolved Sr, while silicate rocks accounted for 35.85 % (2.39 %–57.88 %). Overall, the silicate and carbonate weathering rates in the Liujiang Basin were 6.35 t km−2·a−1 and 22.20 t km−2·a−1, respectively. The atmospheric CO2 consumption flux from silicate and carbonate weathering was 2.27 × 105 mol km−2·a−1 and 2.56 × 105 mol km−2·a−1, respectively. Considering plant biomass management, the carbon sinks of silicate and carbonate rocks in the Liujiang Basin can increase by about 27 % and 4 %. The rock weathering CO2 consumption flux in the Liujiang Basin matches or exceeds other major Chinese rivers, highlighting the importance of small watersheds in carbon sequestration.No Full Tex
Integrating local knowledge and innovative approaches for sustainable water hyacinth management towards livelihoods enhancement in rural India
No full textInvasions of water hyacinth critically threaten aquatic ecosystems and human livelihoods. The study investigates the impact of water hyacinth proliferation on ecological and socio-economic conditions and management strategies in Kuttanad region, India. A mixed-methods approach, including surveys, Participatory Geographic Information Systems (PGIS) mapping, and stakeholder interviews, was employed to investigate the impact on the local communities. Results show that water hyacinths grow in many different backwaters, lakes, and canals and cause significant environmental damage, financial losses, and health issues for local communities. The Composite Vulnerability Index (CVI) of 3.56 (on a scale of 1–5) shows that the Pulinkunnu community is vulnerable to uncontrolled water hyacinth growth. The findings reveal significant environmental degradation, economic losses, especially income from fishing activities, and health risks associated with unchecked water hyacinth growth, highlighting the vulnerability of the affected communities. The study also identifies local knowledge and community engagement as critical components in developing sustainable management strategies that align with the Sustainable Development Goals (SDGs). By proposing innovative solutions like biofertilizer production, the research emphasizes the need for integrated management practices that control the spread of water hyacinth and enhance community resilience and economic opportunities.Full Tex