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FDAU-Net: An efficient optic disc segmentation network with flexible wavelet convolution block and selective dual-attention fusion gate.
Get PDFAccurate segmentation of optic disc regions in fundus images is essential for the diagnosis and monitoring ocular fundus pathology of ophthalmic diseases such as myopia, glaucoma, and diabetic retinopathy. However, challenges such as irregular disc shapes, edge detail preservation, and limited annotated datasets hinder the effectiveness of existing methods. To handle these problems, we propose FDAU-Net, an efficient, fully convolutional network for optic disc segmentation. FDAU-Net integrates the Flexible Wavelet Convolution Block (FWC Block), which combines the dynamic receptive field adjustment of AKConv with wavelet down-sampling to achieve efficient feature extraction while retaining critical edge information. Additionally, we design the Selective Dual-Attention Fusion Gate (SDA Gate) to optimize feature selection and fusion, leveraging channel and spatial attention mechanisms to substantially enhance segmentation accuracy and robustness. To further improve performance, we introduce MedAugment, an automated data augmentation method tailored for medical images, efficiently boosts data diversity in scenarios with low datasets. Experimental results on the iChallenge and IDRiD datasets demonstrate that FDAU-Net consistently achieves superior segmentation performance across key metrics, highlighting its potential for advancing clinical applications
Empowering apartment buyers to avoid building defects by reducing information asymmetries in the apartment development process
Get PDFPurpose – A rapid growth in multi-owned apartment (MOAs) developments around the world has been accompanied by increasing concerns about the high incidence of building defects. Despite the significant economic, psychological and social impacts of defects on MOA building owners and occupiers, research into the organisational and non-technical causes of these defects remains limited and under-theorised. This paper addresses this research gap by reporting the results of a three-year research project in Sydney, Australia which investigated the extent and causes of defects in MOA buildings from an information asymmetry perspective. Design/methodology/approach – Informed by information asymmetry theory, the research is based on a thematic analysis of semi-structured interviews with 66 experts from across the MOA industry in Sydney, Australia. Findings – Findings produce a new typology of 16 information asymmetries which can lead to defects over the MOA development process. We find that almost most key actors involved in the MOA development process are incentivised to hide information about potential defects from MOA customers who are the most disempowered and vulnerable parties in the process. Originality/value – By mobilising information asymmetry theory, this research provides a novel conceptualisation of an important and intransigent problem and new practical insights into how to resolve it. By contributing a new typology of 16 types of information asymmetries in the MOA development process, a series of recommendations are made to ensure that the MOA market has the information to minimise MOA defects and better serve consumers’ interest
Ontogenetic change in body shape for white sharks, Carcharodon carcharias, in Australian waters.
No full textThe analysis of how biological shape changes across ontogeny can provide us with valuable information on how species adapt behaviorally, physiologically, and ecologically. The white shark Carcharodon carcharias is one of the largest and most widely distributed apex predators globally, yet an understanding of ontogenetic changes in body shape and relative scaling of length and weight measures is limited, especially in relation to foraging ecology. Through analysis of a suite of shape-related metrics, we identified ontogenetic patterns of scaling throughout development. Isometric growth was exhibited for most metrics, failing to show a significant deviation from an isometric slope of 1.0 for length-length relationships, and 3.0 for weight-length relationships. The most notable difference from this trend was the negative allometric growth observed for the upper caudal-fin lobe length, trunk length, and the mouth length. The surface area of the fins also presented a strong, positive relationship with precaudal length (PCL) and the girth at the pectoral fin. Negative allometric growth was exhibited for three of the fins (pectoral, upper caudal fin, and lower caudal fin) against PCL, exhibiting a significant deviation from the expected isometric growth of 2.0 for area-length relationships. There were no significant differences in morphometric relationships between geographic regions within Australia that samples were collected from. No differences between the sexes were identified; however, this may be an artifact of the lack of mature animal samples. Conversely, life stage was found to have a significant effect on the girth-length and weight-length relationships. The development of regression equations for morphometric measures allows the assessment of white shark body condition and may serve as an assessment tool to understand the potential impacts of human-induced environmental change on white sharks
Effect of Principal Stress Rotation on Plastic Strain Accumulation in Granular Materials
No full textUnbound granular materials (UGMs) are utilized in flexible pavements to serve mainly as subgrade materials, offering the necessary support for the imposed traffic loads. Although the likelihood of subgrade strength failure under traffic loads is minimal, its permanent deformation is more critical. The repeated load triaxial (RLT) test is a widely employed method for assessing the accumulated permanent deformation in unbound granular materials (UGMs) in their lifetime. Nevertheless, there have been challenges in establishing a direct correlation between the results obtained from RLT tests and the actual deformation measured in full-scale pavements. The primary reason for the disparity is the incapability of RLT-based designs to account for the rotation of principal stresses imposed by the application of shear stress coming from the movement of vehicles. In order to examine how the rotation of principal stress affects the formation of plastic strain in UGMs, various experiments were conducted in the present study. These experiments include different levels of cyclic stress ratio (CSR) and cyclic shear stress ratio (CSSR) using a hollow cylinder apparatus (HCA). The results obtained from the HCA tests were compared to those obtained from the RLT, and it was discovered that incorporating the principal stress rotation significantly amplified the permanent deformation of the unbound granular materials (UGMs). This indicates that incorporating the influence of principal stress rotation is essential for ensuring a proper and accurate design that can effectively address the deformation behavior of the pavement layers
Evaluation of high-strength concrete for lunar applications: Mechanical behaviour under static and dynamic loads at cryogenic temperatures
Get PDFSubstantial advancements in human sciences have greatly accelerated the exploration of celestial bodies. The construction of lunar bases now faces unique and severe environmental challenges, requiring materials that ensure structural integrity and stability. This study examines the static and dynamic mechanical properties of an innovative cement-free lunar high-strength concrete (LHSC). The multi-physics coupling effects of the extreme temperatures (20 °C, −70 °C, and −170 °C) and varying strain rates (approximately 30–200 s−1) were considered to evaluate the dynamic responses of LHSC using a 100 mm-diameter impact apparatus. The findings indicated that the compressive strength of LHSC increased from 129.5 to 153.6 MPa as the temperature decreased, with dynamic strength rising up to 70.8% above static levels at −170 °C. The energy absorption capacity generally improved with strain rate but signally deteriorated under cryogenic conditions. Dynamic split-tensile strength showed a consistent linear increase, with strength-rate sensitivity peaking at −70 °C whereas slightly diminishing at −170 °C. The ice-induced stiffening contributed to heightened material brittleness, leading to abrupt fracture initiation. The dynamic increase factor (DIF) for both compression and split-tension was higher at lower temperatures, highlighting increased rate sensitivity under cryogenic conditions, with split-tensile DIF values exceeding those of compression across all temperatures. Computed tomography (CT) scanning revealed shrinking pores and expanding ice crystals inside LHSC, which strengthened its matrix but also intensified microcrack propagation, reducing the material deformability. These insights are instrumental in developing the construction material specifically designed for the harsh lunar environments, thereby supporting strategies for sustainable extraterrestrial habitation
Lifting the lid on Marine Heatwaves
Get PDFLife is ubiquitous throughout the ocean, with species abundance and richness often greatest below the surface. As a result, ocean extremes throughout the water column may impact resident marine organisms and ecosystems. However, ocean extremes, such as marine heatwaves, have been commonly described based on surface observations. Given the importance of subsurface ocean processes, such as nutrient recycling, (de)oxygenation, and carbon transport, there has been an increasing focus on subsurface marine heatwaves (MHWs). Subsurface MHWs are prolonged warm ocean temperature extremes, and have a diversity of vertical structures linked with different driving mechanisms. Warming may be confined to the surface mixed layer; it may extend much deeper, potentially affecting the entire water column; it may appear only below the surface, with no surface signature, or it may be isolated near to or connected with the seafloor. Based on existing literature and a new analysis of subsurface MHW structure, we propose a comprehensive naming convention, differentiating between mixed layer, deep, thermocline, full depth, submerged and benthic marine heatwaves. Most surface-confined MHWs are associated with surface heat fluxes or shallow ocean advection or mixing. Conversely, many subsurface events are likely related to the vertical or horizontal displacement of temperature gradients/fronts, deep advection, and/or subduction of warm waters below the mixed layer. Different MHW vertical structures also have varying impacts on ocean biogeochemistry. However, due to the sparsity of physical, biogeochemical and biological observations, as well as the complexity of identifying and describing subsurface MHWs, there is limited understanding of the impact of subsurface MHW extremes. The nomenclature proposed in this paper seeks to provide a common language for understanding subsurface MHWs, thus enabling inter-disciplinary studies to quantify their impact
"When it works well, it's great!": Midwives perspectives on the beltless non-invasive fetal electrocardiogram for women in larger bodies in labour.
Get PDFPROBLEM: Higher body weight is linked to an increased risk of certain perinatal complications, hence continuous electronic fetal monitoring in labour is often recommended. Most available devices constrain midwives' ability to optimise women's physiological processes. BACKGROUND: Options for fetal monitoring in labour for women in larger bodies are limited. Evidence demonstrates non-invasive fetal electrocardiography monitors fetal wellbeing more effectively than cardiotocogram. Literature about midwives' experiences of fetal monitoring when caring for women in larger bodies is limited. AIM: To understand the views and experiences of midwives using the beltless non-invasive fetal electrocardiogram when caring for women with BMI≥ 35 kg/m² in labour. METHODS: Findings are derived from a clinical trial that included an implementation study. This article reports on the thematic analysis of focus group and interview data from eighteen midwives (M1-18) across three hospital sites in Australia. FINDINGS: Three themes were identified; Optimising the experience for larger bodied women; Time pressures and troubleshooting; and, Excited for change. DISCUSSION: The beltless design of the non-invasive fetal electrocardiogram was welcomed. Adoption was hampered by challenges related to consistency in fetal heart rate signals. Uterine contraction measurement was perceived as superior to traditional options. CONCLUSION: Midwives are motivated to support women in larger bodies to have positive birth experiences, and they accept that maturing new technologies takes time. While the non-invasive fetal electrocardiogram does not yet fulfil the need for certainty in fetal heart rate connection, midwives responded positively to its beltless design and the reliability of uterine contraction measurement
The Power and the Limits of Zero: Strengths and Pitfalls of CT Coronary Artery Calcium Score in Risk Assessment
No full textAssessing cardiovascular risk by measuring coronary artery calcium (CAC) scoring obtained by computed tomography is well understood and is an accepted practice. It determines the amount of calcium in the atherosclerotic plaque present in the coronary arteries with significant accuracy and establishes the risk of suffering a future cardiac event. CAC scoring enhances the value of traditional risk factors, facilitating improved patient management. In this review, we examined a case with a CAC scoring result and analysed the case to see how it influenced the decision-making process. The case illustrates how decision-making is assisted by CAC scoring in comparison with other cardiac tests, particularly as a basis for initiating preventive therapies, such as statins. Although of such great importance, CAC also has some limitations. CAC cannot identify non-calcified plaque, and in some cases, it can be misleading. This narrative review, supplemented from a practical standpoint, suggests that CAC scanning is generally cost-effective in intermediate-risk groups because it avoids unnecessary lifelong statin therapy in low-risk individuals while targeting therapy to those with demonstrable atherosclerosis. However, considerations of radiation (approximately 1 mSv per scan) and potential downstream testing from incidental findings must be weighed. Most guidelines recommend. From a practical aspect, CAC scanning is generally cost-effective in intermediate-risk groups because it avoids unnecessary lifelong statin therapy in low-risk individuals while targeting therapy to those with demonstrable atherosclerosis. However, considerations of radiation (approximately 1 mSv per scan) and potential downstream testing from incidental findings must be weighed. Most guidelines recommend the selective use, rather than widespread population screening, of cardiovascular risk assessment to balance cost, benefit, and safety
Ensuring Digital Resilience in Australia: From Resilience to Security in Critical Infrastructure Protection
No full textSecure digital infrastructures form the backbone of any modern, industrialised society and economy, and have been the drivers of policy and legislative developments in Australia and other countries worldwide. Australia launched several initiatives to bolster its digital security and resilience, including the 2023–2030 Australian Cyber Security Strategy and Action Plan. The concept of resilience plays a crucial role in critical infrastructure protection in Australia. Security and resilience work together in a critical infrastructure setting. This chapter outlines the legal framework that underpins the security of critical infrastructure in Australia by exploring the operative provisions of the Security of Critical Infrastructure Act 2018 (Cth). The chapter considers the complex interplay between regulation, resilience, and security, noting some of the challenges and opportunities of this crucial relationship
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