Influence of limestone calcined clay on the mechanical behaviour of 3D printed engineered cementitious composites

Utilisation of engineered cementitious composites (ECC) for additive manufacturing can help improve the toughness and deformability of printed structures, while it is vital to further enhance its sustainability for engineering applications. In this study, limestone calcined clay was adopted as an alternative low-carbon binder to cement at replacement levels of 0, 30 % 45 % and 60 % for 3D printed ECC. The mechanical properties of printed ECC based on limestone calcined clay cement (LC3) were systematically investigated. Results reveal that the tensile strength of printed ECC dropped but the strain capacity raised with increasing limestone calcined clay substitution. All printed LC3 based ECC exhibited strain hardening behaviour and have a tensile strain of over 2 %. The compressive and flexural strengths of cast specimens declined with increasing limestone calcined clay content, while the strengths of printed counterparts improved when loaded in individual printed directions. Interlayer bonding strength of the printed LC3 based ECC in the horizontal direction reduced by 3.58 %–8.32 % while that in the vertical direction raised by 5.69 %–9.64 % than strengths of printed ordinary ECC. Fracture toughness of printed ECC significantly decreased with increasing limestone calcined clay substitution. Nevertheless, the interlayer fracture toughness of printed LC3 based ECC achieved 65 % of the internal fracture toughness, where the bridging effect of fibres embedded in the interlayer resulted in an enhancement of interfacial performance. Overall, the printed ECC showed desirable mechanical properties due to the enhancement of ductility and interlayer bonding behaviour when the substitution of limestone calcined clay is below 45 %

Decentralization: A Qualitative Survey of Node Operators

Decentralization is understood both by professionals in the blockchain industry and general users as a core design goal of permissionless ledgers. However, its meaning is far from universally agreed, and often it is easier to get opinions on what it is not, rather than what it is. In this paper, we solicit definitions of ‘decentralization’ and ‘decentralization theatre’ from blockchain node operators. Key to a definition is asking about effective decentralization strategies, as well as those that are ineffective. Malicious, deceptive or incompetent strategies are commonly referred to by the term ‘decentralization theatre.’ Finally, we ask what is being decentralized. Via thematic analysis of interview transcripts, we find that most operators conceive of decentralization as existing broadly on a technical and a governance axis. This informs a two-axis model: network topology and governance topology, or the structure of decisionmaking power. Our key finding is that ‘decentralization’ alone does not affect ledger immutability or systemic robustness

Zero-Shot Monocular Metric Depth for Endoscopic Images

Monocular relative and metric depth estimation has seen a tremendous boost in the last few years due to the sharp advancements in foundation models and in particular transformer based networks. As we start to see applications to the domain of endoscopic images, there is still a lack of robust benchmarks and high-quality datasets in that area. This paper addresses these limitations by presenting a comprehensive benchmark of state-of-the-art (metric and relative) depth estimation models evaluated on real, unseen endoscopic images, providing critical insights into their generalisation and performance in clinical scenarios. Additionally, we introduce and publish a novel synthetic dataset (EndoSynth) of endoscopic surgical instruments paired with ground truth metric depth and segmentation masks, designed to bridge the gap between synthetic and real-world data. We demonstrate that fine-tuning depth foundation models using our synthetic dataset boosts accuracy on most unseen real data by a significant margin. By providing both a benchmark and a synthetic dataset, this work advances the field of depth estimation for endoscopic images and serves as an important resource for future research. Project page, EndoSynth dataset and trained weights are available at https://github.com/TouchSurgery/EndoSynth

Validated self-administered screening tools to identify depression among young adults (18 to 25-years-old) in East Asia and the Pacific Region low-and-middle income countries (LMICs): A systematic review

This systematic review evaluates the validity, reliability, and diagnostic accuracy of self-administered screening tools for symptoms of depression among young adults (18 to 25 years old) in East Asia and the Pacific. A total of 22 studies with 24,069 participants were included, covering both clinical and non-clinical populations. Nine self-administered screening tools were identified, with Patient Health Questionnaire-9 (PHQ-9), Patient Health Questionnaire-2 PHQ-2, and Centre for Epidemiological Studies Depression (CES-D) being the most frequently studied. PHQ-9 demonstrated moderate to excellent internal consistency reliability, with Cronbach’s alpha ranging from 0.67 to 0.92, and a pooled AUC of 0.86, indicating strong screening accuracy. PHQ-2, showed an Area Under the Curve (AUC) of 0.85, high sensitivity (0.96), and moderate specificity (0.80). CES-D exhibited an AUC of 0.87, good sensitivity (0.81), and specificity (0.78), with high heterogeneity (I² = 74.70 %–86.69 %). The meta-analysis revealed substantial variability in sensitivity and specificity across settings, with differences in study methodologies, cutoff scores, and reference standards contributing to high heterogeneity. Additionally, 95.5 % of studies had a moderate risk of bias in patient selection, affecting generalizability. Despite these limitations, PHQ-9, PHQ-2, and CES-D remain valuable tools for identifying symptoms of depression among young adults. The accessibility, ease of administration, and strong psychometric properties of these tests support their continued use in resource-limited settings, though standardization of methodologies and expanded regional validation are needed to improve screening accuracy and applicability

Large Language Model-Augmented Model Predictive Control for Marine Vessels in Uncertain Marine Environments

This paper presents a novel control framework that integrates Large Language Models (LLMs) with Model Predictive Control (MPC) to improve ship navigation performance under uncertain and variable marine conditions. The LLM is fine-tuned using synthetic datasets generated from a 2D ship model with injected environmental disturbances, enabling it to learn residual dynamics not captured by the nominal model. During operation, the LLM estimates real-time model error as a function of the current vessel state, control input, and exogenous factors such as wave height and wind speed. This estimated uncertainty is incorporated into the MPC prediction model, resulting in enhanced state forecasting and more robust control decisions. Simulation results demonstrate that the LLM-MPC framework significantly reduces steady-state tracking errors, improves convergence rates, and smoothens control actions compared to MPC only without LLM estimation. This approach offers a scalable, data-efficient solution for enhancing autonomy in intelligent marine systems operating in complex ocean environments

Learning from the past; thinking for the future: Reflections on STEM and its integration in formal and informal settings

We discuss opportunities to integrate STEM across both formal and informal settings. Our reflections begin with looking back to Making Science Matter: Collaborations Between Informal Science Education Organizations and Schools, an influential report published by the Center for Advancement of Informal Science Education (CAISE) in 2010. We expand the arguments in that report to address integrating STEM education in formal and informal education particularly in the light of the growth of interest in teaching about ‘wicked problems’. We discuss several issues that we believe need to be taken into account in developing closer formal/informal collaboration, and trace how they have emerged since the term STEM was first used in the 1960s. We conclude that a significant challenge, that is often overlooked, is that the term STEM has several different meanings and that institutions in formal and informal settings may have different outcomes in mind when collaborating with each other. The implications are that discussing the meaning and purpose of STEM are an essential first step in any collaboration between formal and informal institutions

The moderating role of pre-adoptive reflective functioning in the association between early adversity and child difficulties after transnational adoption: a 4-year follow-up study

Early adversity is associated with an increased risk for psychopathology and behavioral difficulties among transnational adoptees. Pre-adoptive reflective functioning may be an important buffer in this relationship. However, no studies have investigated this in adoptive families. Using longitudinal data from the Leuven Adoption Study (N = 48 participating families), this study investigated whether anthropometric proxies of early adversity (assessed in terms of child age, body mass index (BMI), weight for age, and length for age, based on parental reports of child weight and height at placement) predicted child difficulties assessed with the Child Behavior Checklist 4 years after child placement. The study also investigated the potential moderating role of adoptive parents’ pre-adoptive reflective functioning, as assessed by the Reflective Functioning Scale scored on the Adoption Expectations Interview. All associations were investigated controlling for the effects of child temperament, as measured by the short versions of the Infant Behavior Questionnaire or the Early Childhood Behavior Questionnaire. Results indicated that child age at placement and low BMI predicted socioemotional difficulties. Pre-adoptive reflective functioning among fathers, but not among mothers, buffered against the effect of early adversity on child socioemotional difficulties. Conversely, low paternal levels of reflective functioning were associated with greater effects of early adversity on socioemotional difficulties. This study identified fathers’ capacity for reflective functioning as a buffer against socioemotional difficulties. Implications for future research and practice, in terms of effective early interventions, are discussed

Reaction mechanisms of coal gasification in supercritical water with CO₂ transport agent: A ReaxFF molecular dynamics study

Supercritical water gasification (SCWG) is a promising technology for efficient and low-carbon coal utilization. As a potential transport agent, introducing CO2 into SCWG offers a prospect for optimizing the gasification environment and reducing carbon emissions. In this study, a novel coal SCWG process using CO2 as the transport agent is investigated through reactive force field molecular dynamics (ReaxFF MD) method. The reaction mechanisms of coal fragment decomposition and gaseous product generation, along with the effects of key operating parameters, are revealed at the molecular level. The initial coal breakage primarily occurs at C-O bonds, followed by ring-opening and carbon chain cleavage reactions. Three primary ring-opening routes involving direct cleavage, contracted-ring cleavage, and expanded intermediate cleavage are identified. These processes are significantly facilitated by active O and OH radicals generated from CO2 and water dissociation, which effectively weaken C–C bonds within the carbon structure. H radicals derived from water serve as key intermediates for H2 formation through radical recombination. CO2 contributes to CO production both through direct decomposition and by providing reactive O radicals that oxidize coal fragments. CO2 addition increases the CO/H2 molar ratio and enhances the decomposition of coal macromolecules. An appropriate CO2 range of 100–300 molecules further improves carbon conversion efficiency. Moreover, higher reaction temperatures and higher water concentrations are beneficial to promote hydrogen production and carbon conversion