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Defect chemistry manipulation by heavy ion irradiation in Y-doped CeO2 solid solutions
Get PDFA combination of experimental methods is used to study the effect of trivalent cation doping and radiation stability of Y-doped CeO2 with dopant content ranging from 0–15 wt%. X-ray diffraction reveals that Y-incorporation leads to long-range ordering of anionic vacancies with randomly distributed C-type Y2O3 nanodomains that form coherently within the host fluorite structure. Raman and positron annihilation spectroscopies are employed to characterise and analyse the nature of oxygen vacancies that charge the aliovalent direct substitution and Ce3+ formation. Heavy-ion irradiation at different fluences (1 × 1016 and 5 × 1016 ions per cm2) shows that the doped compositions offer improved resistance to radiation damage. These findings are attributed to the ballistic mixing of dopant-induced defects with those introduced by ionic implantation, thereby increasing defect recombination volume and enhancing lattice recovery. Furthermore, the defect migration and annealing mechanisms are seen to differ for the studied fluences, highlighting the specific role of sample surfaces as effective annealing sites
Effect of energy density on microstructure control in precipitation hardening steel during powder bed fusion
Get PDFWe demonstrate how controlling the heat affected zone during laser powder bed fusion may be used to optimise the phase composition of additively manufactured (AM) components in-situ to reduce post-processing heat treatments. We showcase this approach by promoting in-situ precipitation hardening in martensitic 17-4 PH stainless steel by varying the laser energy density. We link the melting and reheating associated with the layer-wise metal consolidation to the phase evolution and local material hardness, providing guidelines to achieve ‘print and use’ strategies for precipitation hardened alloys. These processing strategies may yield AM parts with lower cost, time, and embodied energy
Measurement of grit wear in abrasive c-BN electroplated tipped blades for gas turbines applications
Get PDFThe increasing use of ceramic abradable seal systems in the High-Pressure Turbine section of gas turbines, aimed at improving efficiency and reducing fuel consumption, introduces new challenges in performance evaluation. This work proposes a standard method to quantify wear on c-BN electroplated tipped blades, which function as abrasive coatings on rotor blades. The approach relies on 3D metrology scanner to capture surface data of the blade and converting them into measurable parameters that allow for consistent comparison between blades from rig testing. Key metrics include grit density, the volume occupied by abrasive particles, and the corresponding void volume and void density resulting from wear. An additional parameter is proposed to account for debris accumulation and its effect on the proposed wear-related metrics. The results demonstrate consistent trends across the proposed parameters, both in pristine and tested blades, regardless of their initial grit density as well as with grit wear patterns. The proposed Positive Volume Variation (PVV) and Grit Density Variation (GDV) metrics exhibited a strong mutual correlation (r = 0.950), a result supported by their shared underlying physical basis. In contrast, the Mean Height Variation (MHV), typically applied to bare blades, demonstrated weaker correlations with both PVV (r = 0.893) and GDV (r = 0.745)
A universal of human social cognition:Children from 17 communities process gaze in similar ways
Get PDFTheoretical accounts typically assume that key features of human socio-cognitive development are universal. This paper reports a large-scale cross-cultural study (17 communities, diverse ethnicities, N = 1,377, 709 female, mean = 5.50 years, -collected March 2022 to January 2024) on gaze following in early childhood. To test for universality, cognitive processing signatures were derived from a computational model treating gaze following as social vector estimation. Results showed substantial variation between communities and individuals. Yet, the processing signature was found in all communities. Individual differences in performance were related to children's familiarity with the data-collection device but not opportunities for social interaction. These results provide strong evidence for gaze following as a universal socio-cognitive process despite cultural and individual-level variation in absolute performance
Is there a right to family reunification for refugees in Latin America?
Get PDFRefugees often end up separated from their families when they cross international borders. While the right to family life and unity is enshrined in different international human rights documents, the right to family reunification is contested. This paper discusses the right to family reunification for refugees in Latin America by explaining family reunification as a human right in the region and the expanded definition of family based primarily on economic dependency. I conducted a thematic analysis of (a) regional documents on human rights and asylum in Latin America, (b) the Inter-American Court of Human Rights jurisprudence and (c) the national asylum legislation of Latin American countries. There has been a consolidation of the right to family reunification for refugees in Latin America as a region, as most countries have directly guaranteed a right to family reunification in their asylum legislation and indirectly by recognising the principle of family unity. Most countries in the region (except Colombia) tend to adopt an expanded definition of family in their asylum legislation. However, it is based on the idea of economic dependency, rather than emotional dependency, as defined by the Inter-American Court of Human Rights in its Advisory Opinion 21/2014
Transcutaneous vagus nerve stimulation during motor activity in healthy volunteers: a high-density diffuse optical tomography study
Get PDFBackground: Stroke is a leading cause of long-term disability worldwide. Non-invasive or transcutaneous auricular vagus nerve stimulation (taVNS) shows promise in promoting neuroplasticity and supporting motor recovery. There are currently no validated biomarkers of taVNS. High-density diffuse optical tomography (HD-DOT) is a portable neuroimaging technology that uses near-infrared light to map cortical activity via the quantification of changes in blood oxygenation. The aim of this study was to determine whether HD-DOT could detect motor task-related activity with concurrent taVNS.
Methods: Thirty-one healthy participants completed right and left finger tapping tasks with concurrent sham (earlobe) and then active (tragus) taVNS in a within-subject block design. HD-DOT was recorded across the bilateral sensorimotor cortex using 36 sources and 48 detectors (1728 channels). Cortical reconstructions were parcellated and block-averaged task-related oxygenated and deoxygenated haemoglobin changes were compared between sham and active taVNS conditions.
Results: In a group-level analysis, appropriate lateralised task-related haemodynamic responses were seen in the contralateral sensorimotor regions, demonstrating the validity of HD-DOT. Between-group comparisons showed no significant change in task-related activation during right finger tapping tasks under active vs. sham taVNS conditions. A non-significant redistribution of task-related activity to the right motor cortex was seen with left finger tapping under active taVNS compared to sham taVNS.
Conclusions: Simultaneous recording of neural responses to taVNS during motor activity was feasible and well tolerated. Reliable task-related activation was recordable. Future studies of whole brain HD-DOT in people with stroke will help evaluate its potential as a biomarker in taVNS
Incidental food nanoparticles from freshwater clam soup stabilize Pickering emulsions
Get PDFDaily foods contain abundant amounts of nanoparticles produced by the self-assembly of amphiphilic food components during processing. These nanoparticles are referred to as incidental food nanoparticles (iFNPs) because they are formed incidentally rather than through a specific nanoparticle fabrication method. Among them, freshwater clam soup nanoparticles (FCNPs) have potential as nanocarriers, but their capacity as stabilizers for pickering emulsions (PEs) has not yet been explored. This study investigated the feasibility of FCNPs as stabilizers for food-grade PEs. FCNPs were characterized and showed a contact angle of 54.64 ± 1.06°, indicating their suitability for stabilizing O/W PEs. FCNPs stabilized medium-chain triglycerides at different concentrations (1%-5%) and oil fractions (φ = 20%-80%) to form PEs or high internal phase PEs with excellent stability. These PEs were dominated by elastic gel-like and typical shear-thinning behavior. Increasing either the FCNPs concentration or the oil fraction was resulted in emulsions with smaller droplets and higher gel strength. These FCNPs-stabilized PEs were stable at 4 °C for 90 days and across broad ionic strength (0-600 mM) and pH (3-11) ranges, as well as under pasteurization treatments. These findings provide new insight into the development of food-grade PEs by utilizing iFNPs, widely present in daily foods, as a novel class of safe, effective, and ‘clean-label’ stabilizers
Clinician and patient experiences with opportunistic offer of HPV self-testing in Aotearoa New Zealand primary care clinics: interview and survey findings
Get PDFBackground
To support the introduction of human papillomavirus (HPV) self-testing in the New Zealand National Cervical Screening Programme, we conducted an implementation study aimed to explore the acceptability and feasibility of opportunistically offering HPV self-testing in general practice from both clinician and participant perspectives with a home testing option and centralised follow-up.
Methods
Primary care clinicians trained to offer the HPV self-test were invited to semi-structured interviews exploring their perception of receptivity to the opportunistic offer and challenges and enablers to implementation. Reflexive thematic analysis was undertaken on transcripts. Participants (aged 30–69 years) were sent a link to an online survey after HPV result notification. Survey results were analysed using descriptive statistics with an inductive approach to analysis of free text responses. Participant recruitment and data collection occurred between November 2021 and January 2024.
Results
Of the 40 clinicians trained to offer HPV self-testing, 12 primary care clinicians from six ethnically diverse primary care sites in Auckland completed an interview. ‘Positive reception’ was the strongest theme with clinicians reporting that overwhelmingly, participants were receptive to the HPV self-test offer. The four enabler themes were: ‘supportive practice systems’, ‘importance of the discussion’, ‘options for testing' and ‘specialised support and consistency’. Key challenge themes in implementing opportunistic self-testing were ‘competing demands’ and ‘communicating what it’s all about’.
Of the 3,524 self-tested participants, 394 responded to the survey. Most (93%) found the amount of information they received about HPV self-testing ‘about right’ and 86% were comfortable in their decision to self-test. Considering their next cervical screening, more respondents preferred home-based self-testing options than self-testing at a clinic (46% versus 37%).
Conclusion
Offering the HPV self-test opportunistically to people due for screening when they visited their primary care provider for any reason was generally well received and feasible for clinic staff. The option to take kits home for sampling was an enabler of participation. Supportive systems and resources for clinicians will be important if opportunistic HPV self-testing is offered more widely in primary care, including further consideration of a central specialist team to follow-up and support home testing and participants with HPV detected results.
Trial registration
This study did not reach the ICJME or WHO criteria for clinical trial registration
Avoiding corporate amnesia in health systems – the need for organizational memory
No full textBalancing finite resources with rising demand remains a universal challenge for healthcare systems. Organizational decision making is increasingly shaped by cost-efficiency, yet efficiency is often mistakenly equated with effectiveness. Systems may reduce costs and waiting times but still fail to improve individual health outcomes, risking population health in pursuit of financial balance. In England, efforts to curb the ballooning health budget include the dissolution of NHS England and its merger with the Department of Health and Social Care. These reforms, while aimed at streamlining services, risk eroding organizational memory—knowledge embedded in people, processes, and practices. Organizational memory guides current decisions, prevents repetition of failed measures, and supports innovation. Its loss, especially through staff attrition and restructuring, may paradoxically undermine the very improvements these reforms seek to achieve. Singapore's healthcare system offers a counterfactual example, demonstrating how effective use of organizational memory—through electronic health records, regionalized clusters, and preventive care initiatives—can lead to adaptive, efficient, and high-quality care. Gulf Cooperation Council countries, including Qatar, are adopting similar strategies, using rich patient data to inform research and policy. Organizational memory is not an afterthought but a foundational asset. As healthcare systems evolve under financial, technological, and patient-centered pressures, preserving and leveraging organizational memory is essential. Reforms must be designed not only to improve efficiency but also to sustain effectiveness and ensure long-term improvements in patient outcomes
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