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Seismic response of sand beds in a laminated shear stack: physical and numerical modelling
No full textThis paper presents the design and workings of a new type of laminated shear stack container. Several experiments were conducted involving a sand bed placed inside the shear stack that was excited horizontally under a variety of input excitations. A two-dimensional (2D) finite element model of the shaking table and laminated shear stack containing the sand bed was developed, incorporating details of the table and laminated shear stack design. The capability of the finite element model to replicate the dynamic response of the naked table, and of the sand bed inside the laminated shear stack when interacting with the table, were verified. The finite element model was extended to explore important aspects of the sand and laminated shear stack behaviours, including how the use of energy absorbing boundaries in the laminated shear stack enable parts of the sand model to exhibit field-equivalent responses. For low to moderate ground shaking it is shown that the chosen stiffness for the energy absorbing boundaries does not have a significant influence on the seismic performance of the sand bed at its center. Demonstrations of similitude are also given. Large size differences between model and field scales may be associated with attenuations of stress waves and de amplifications of accelerations that are not insignificant
Collaborative governance in marine and coastal management: A systematic review
No full textStrengthened collaboration across different levels of governance can lead to improved marine and coastal management outcomes. For example, collaborative governance can improve coordination between institutions and communities, enhance trust to facilitate the participation of diverse actors, and build capacity for shared decision-making among both state and non-state sectors. While interest in collaborative governance for marine and coastal systems is growing, critical gaps in the scholarship remain, particularly regarding its implementation and success. Systematically identifying these knowledge gaps is essential to guide future research efforts and funding investments. To address this, we systematically reviewed empirical case studies, examining the roles of actors, the barriers and opportunities to collaboration, and the outcomes reported. We applied qualitative thematic analysis to identify key themes across the studies. A total of 4196 articles were retrieved from literature databases, and after a multi-stage screening process, 60 articles qualified for inclusion in the systematic review. We find that while collaborative governance involves a diversity of actors in marine and coastal settings, power remains unevenly distributed, often concentrated within the state. Our findings further highlight that essential conditions for supporting and sustaining collaborative governance include power sharing, legitimacy, engagement with bridging actors, and access to financial resources. Finally, we emphasise the need for standardised approaches to evaluating both social and ecological outcomes. This review contributes a roadmap for advancing collaborative governance research in marine and coastal contexts and offers recommendations to better align theory with practice
Bio-inspired soft robotic system for reproducing myocardial biomechanics
No full textIn-vitro models of cardiovascular biomechanics/hemodynamics have emerged as a stable, controllable testbed for research into cardiac (dys)function, the development of mechanical circulatory support (MCS) devices, and the development of surgical devices and training. In recent years, researchers have turned to copying the myocardial architecture of the human heart to create biomimetic in-vitro models. Great progress has been made, but no existing model can accurately replicate the complex motions of the heart due to oversimplifications and choice of actuation. This thesis introduces a new framework for the use of soft robotic artificial muscles in physical cardiac simulators that faithfully recapitulate cardiac motion and hemodynamics in both health and disease. The feasibility of using inverse hydraulic artificial muscles in the development of a soft robotic fluid pump is first demonstrated, before developing a fabrication process that allows these muscle fibers to be arranged in close agreement to the myocardial architecture of the left ventricle. The biomimetic structure of the model is demonstrated to facilitate replication of the motions of the four phases of the cardiac cycle. A closed-loop control system was then developed to modulate the effective stiffness of the artificial ventricle, allowing for the simulation of heart failure with preserved ejection fraction (HFpEF) with the addition of a muscularized left atrium. Support of the diseased left heart is also demonstrated with a left ventricular assist device. Finally, this thesis then details the design and integration of a left-heart endocardial membrane, with functioning mitral and aortic valves, into the ventricular musculature. The membrane is fabricated using 3D printed molds and can be programmed for patient/disease specific internal cardiac geometry. With control over the papillary muscles in the mitral valve apparatus, variable mitral valve dysfunction can be induced and analyzed using clinical echocardiographic techniques. This left heart simulator is then demonstrated as a testbed for the development of a minimally invasive soft robotic catheter and its control system. This high-fidelity cardiac simulator, and those that follow, offer a stable, controllable platform for investigations into cardiac disease and the devices and tools that are used for treatment, reducing reliance on animal models, and improving outcomes in humans
Associations between multiple neurodevelopmental disorders and mental health in children
No full textObjective: This study investigated the association between multiple NDDs and the prevalence and severity of current depression and anxiety among children aged 3–17 years. Methods: We analyzed parent- or caregiver-reported data from 2016 to 2023 US National Survey of Children's Health. Children aged 3–17 years were included. We considered a broader spectrum of NDDs by including behavioral problems and grouped children based on the number of NDDs (out of ten): no multiple NDDs (none or one NDD), two NDDs, three NDDs, four NDDs, and five or more NDDs. Four mental health outcomes were measured: depression (yes/no), anxiety (yes/no), depression severity (mild/moderate/severe), and anxiety severity (mild/moderate/severe). Multinomial logistic regression models were used. Results: Among 267,044 children (mean age = 10.2 years; male = 51.8 %), 10.6 % had multiple NDDs. The increasing number of co-occurring NDDs was associated with higher odds of prevalence and severity of depression and anxiety. Children with multiple NDDs were 4.7–5.3 times more likely to have depression and 5.8–12.9 times more likely to have anxiety compared with those without multiple NDDs. These positive associations remained consistent for mild or moderate depression (adjusted odds ratios [ORs]: 5.0–5.6) and for mild or moderate anxiety (adjusted ORs: 5.6–8.9). The associations were more pronounced for severe mental health conditions, with children being 7.8–16.9 times more likely to experience severe depression and 8.1–34.9 times more likely to experience severe anxiety. Conclusions: The cumulative mental health burden associated with multiple NDDs emphasizes the need for integrated screening and tailored interventions to support this population
Can AI developers avoid bias in public health applications?
No full textDevelopments in the field of engineering biology and artificial intelligence have made it increasingly possible to deliver personalised treatments which are tailored to the individual and can help prevent illnesses before they occur. While such advancements have important implications for public health, the use of AI-enabled personalised treatments comes with potential downsides, not least of which is the potential for bias which may cause harm to certain subpopulations. As one of the key actors in the AI development pipeline, developers are ideally placed to ensure that treatments are designed in an equitable manner. However, existing bias mitigation strategies often fail to consider the practical challenges faced by developers which can significantly impact their abilities to detect and remove bias from any treatments which they help to design. In this paper, we highlight some of the practical challenges that developers face in mitigating bias. We also consider the implications of acknowledging such limitations for attributing responsibility related to bias mitigation
Assisted Self-Governance: The CASS Model of Volunteering among Older Immigrants
No full textIn Australia's multicultural ageing context, older immigrants’ community participation is shaped by institutional arrangements that value inclusion yet struggle to accommodate cultural difference. This article examines how CASS Care Ltd, a long-standing community organisation, supported culturally and linguistically diverse (CALD) older adults to become volunteers. Drawing on qualitative analysis of group activities and interviews, the study finds that the defining feature of the CASS Model is assisted self-governance, composed of three interdependent elements: empowerment, institutional support, and cultural sensitivity. Together, these elements explain how older immigrants transition from passive service recipients to active community volunteers. We argue that assisted self-governance is a practical model of culturally responsive governance through which volunteering becomes both community-led and institutionally supported and sustained. By theorising this model, the article advances understandings of ageing, migration, and multicultural governance, illustrating how inclusion can be achieved through relational and culturally grounded forms of organisation
Oxygen‐Substituted Porous C2N Frameworks as Efficient Electrocatalysts for Carbon Dioxide Electroreduction
No full textAbstract The electrochemical carbon dioxide reduction reaction (CO 2 RR) provides a green avenue for decarbonizing the conventional chemical industries. Here, a structure–selectivity relationship of catalysts is pivotal for the control of a highly selective and active CO 2 RR pathway. We report the fabrication of an oxygen‐substituted C 2 N as metal‐free catalyst (O─C 2 N) for electrochemical CO 2 ─to─CO conversion with tunable O microenvironment. Combined spectroscopic analysis reveals a fine tailored N─C─O moiety in O─C 2 N, where C─O─C species (e.g., ring in‐plane ether) become the dominant oxygen configurations at higher pyrolysis temperatures. Based on experimental observations, a correlation between the exocyclic O‐substituted N─C─O─C moieties and CO selectivity is established, giving clear chemical tools for active structure design. The optimized O─C 2 N electrocatalysts with the dominant appearance of C─O─C moieties exhibit an outstanding 2e − CO 2 RR performance with a CO selectivity up to 94.8%, which can be well maintained in a practical flow‐cell reactor with an adjustable syngas feature
Drivers, barriers, and implications of mpox vaccine uptake in Australia among gay, bisexual, and other men who have sex with men: results from a prospective observational mixed-methods study (2022–2024)
No full textBackground Unlike other high-income countries that experienced mpox outbreaks in 2022, Australia had low case numbers before a significant resurgence in 2024, with 99 % of cases occurring in males. Vaccine coverage among gay, bisexual, and other men who have sex with men (GBMSM) was estimated at 50 %. We identified drivers and barriers to vaccine uptake and discuss implications for mpox control in Australia. Methods The TraX study, established in 2022, was a mixed-method prospective observational study of GBMSM and their sexual partners tracking mpox vaccine uptake through weekly surveys. Two multivariable logistic regression models identified predictors of receiving one and two doses. We analyzed qualitative responses from unvaccinated participants using the Framework Method. Results A total of 3596 participants were recruited through a waitlist, vaccine hubs, and community networks. In 2024, 1224 responded and were included in this analysis. Among community-recruited participants, 82.8 % had received at least one dose, associated with living in areas where ≥5 % of residents were gay men, living with HIV, recent sexually transmitted infections (STIs), greater COVID-19 vaccine history, non-relationship sex, group sex, international travel, and mpox concern. Among all participants, 83.7 % had completed the second dose, associated with older age and non-relationship sex. In qualitative analysis of 57 unvaccinated participants, most cited low perceived risk based on geography or sexual behavior. Reported barriers included difficulty accessing services, limited vaccine knowledge, and concerns about side effects. Conclusions This study found high uptake of the first mpox vaccine dose and a high rate of second dose completion. Most participants made decisions aligned with public health guidance, though some underestimated their risk. With low vaccine coverage and natural immunity, Australia's 2024 mpox outbreak likely reflected insufficient population-level protection. Australia likely entered 2024 with little infection induced immunity because few cases had occurred in 2022–2023, and with incomplete vaccine coverage among people at ongoing risk. Our findings point to practical steps to prevent future outbreaks by increasing vaccination rates, including addressing side-effect concerns, streamlining vaccination, and improving awareness of personal risk factors
Manifestations of Physics beyond the Standard Model in Atomic and Molecular Phenomena
No full textThe Standard Model of elementary particles comprises the fundamental building
blocks of observable matter. To date, it is one of the most successful theories in
physics. Despite this, it is not complete. There remains a list of fundamental physical
phenomena which go unexplained by the Standard Model. Most notably, it is unable
to explain the observed matter-antimatter asymmetry in the universe, fails to supply
an adequate candidate dark matter particle and is unable to explain the origin of
dark energy. Efforts to extend the Standard Model in order to account for these
phenomena have become a focus of contemporary physics.
The use of atomic and molecular systems to probe dark matter interactions and
test the stability of fundamental constants is a central focus of this thesis. Interactions
with ultralight scalar and pseudoscalar fields can induce variations in these
constants, altering the hyperfine structure of atoms and molecules. To exploit this,
a new mechanism is proposed in which scalar field dark matter may be detected
through its effect on hyperfine transitions in alkali atoms. It is further shown that
comparing the variation of the electric quadrupole hyperfine constant with that of
the magnetic dipole hyperfine constant offers enhanced sensitivity to the dark matter
interaction. Atomic clock comparisons provide an additional and complementary
avenue, and data from these experiments are used to constrain the variation of
hadronic parameters, ultralight dark matter models, possible violations of the Einstein
Equivalence Principle, and the existence of long-range forces beyond gravity.
In parallel, constraints are obtained on the variation of the QCD interaction scale,
ΛQCD, within a framework where a dark matter or dark energy field couples to it
through a sole gluonic channel, and its prospective sensitivity to the anticipated
229Th nuclear clock is examined.
A complementary focus of this work is the study of enhanced nuclear moments
that violate the fundamental symmetries of parity (P) and time reversal (T). Such
moments provide sensitive tests of theories predicting CP violation and are directly
relevant to explaining the observed matter-antimatter asymmetry of the universe. In
octupole-deformed nuclei, near-degenerate states of opposite parity are mixed by Tand
P-violating nuclear forces, aligning the nuclear axis with the spin and allowing
the otherwise forbidden intrinsic Schiff, electric dipole, and magnetic quadrupole
moments to manifest in the laboratory frame with large amplification. Calculations
of these moments are presented for isotopes predicted to exhibit octupole deformation,
showing that Schiff and magnetic quadrupole moments are significantly
enhanced compared with those in spherical nuclei. When coupled to electrons,
these moments induce T, P-violating atomic and molecular electric dipole moments,
greatly increasing the sensitivity of EDM searches. The implications of these enhancements
are explored for atoms, molecules, and solids containing such nuclei,
highlighting their potential utility in tests of unification theories and in the search
for axion dark matter
Surface Proteomic Analysis Reveals the Presence of Noncanonical Cell Membrane Endoplasmic Reticulum Chaperones in High-Grade Gliomas
No full textHigh-grade gliomas (HGG) are highly aggressive tumors, which are predominately fatal for adults and pediatric patients. Identifying cancer-selective therapeutic targets remains a critical unmet need. The overexpression of endoplasmic reticulum (ER) chaperones in various cancers is well documented. Moreover, tumor cells exhibit an atypical surface expression of ER chaperones, suggesting the potential for selective targeting. Our study examined the differences in the mRNA, total protein, and surface expression levels of seven key ER chaperones, compared with those in non-neoplastic samples. Notably, a poor correlation was found between mRNA, protein, and surface protein levels, underscoring the limitations of transcriptomics alone in target discovery. We also highlight the limitations of surfaceome studies which exclude noncanonical membrane proteins, such as ectopically expressed ER chaperones, which often escape detection by conventional bioinformatic pipelines. For the first time, this study advances our understanding of the surface expression of ER chaperones in both adult and pediatric HGG. Our findings highlight the importance of surfaceome analysis in the discovery of cancer selective targets against this devastating disease