Open Research Exeter - University of Exeter
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Humans self-organise balance control strategies on a dynamic platform
No full textThe human body continuously detects and predicts environmental disturbances and adaptively generates corrective responses to maintain standing balance. According to dynamical systems theory, these responses are self-organised, emerging naturally during human-environment interaction. Building on this, we introduce a model predictive controller (MPC) framework to simulate postural responses to environmental perturbations caused by a dynamic underfloor platform. The model uses a four-segment biomechanical system with sensory feedback and predicts the optimal response for maintaining balance, while accounting for biomechanical constraints, as the frequency of mechanical perturbation increases. The model findings, validated by the performance of nine young participants, provide evidence that indeed postural strategies emerge autonomously from the body’s dynamic interaction with the mechanical perturbation, without manual tuning. The emergent behaviour involves non-linear transitions from ankle to knee strategy, followed by transition in the relative motion between the centre of pressure and centre of mass as platform frequency increases. We demonstrate that effective models should include ankle, knee, and hip joint motion, with hip motion being less mechanically efficient in young people. The proposed framework also overcomes the limitations of traditional models which fail to capture the transitional dynamics and provides novel insights into the self-organising nature of postural responses.</p
Heat transport and dissipation in 2.5D rotating internally heated and cooled convection
No full textModels of astrophysical convection, such as mixing length theory, typically assume that the heat transport is independent of microphysical diffusivities. Such 'diffusion-free' behaviour is, however, not observed in numerical simulations employing standard fixed-flux or fixed-temperature boundary conditions, except possibly in extreme parameter regimes that are computationally expensive to achieve. Recent numerical and experimental work has suggested that internally heated and cooled convection can exhibit diffusion-free scalings in more numerically accessible regimes. Here, we present direct numerical simulations of 2.5D Cartesian rotating thermal convection driven by an internal heating and cooling function. The use of distributed heating and cooling functions alleviates sharp thermal boundary layers that would otherwise be present, allowing the flows to be simulated with modest computational resources. We show that for high Rossby numbers this set-up recovers mixing length theory scalings for the heat transport. The velocity amplitudes, in contrast, are observed to display diffusion-limited scalings. By comparing against boundary driven rotating convection, we show that internally heated cases have a larger fraction of their thermal dissipation occuring in the bulk of the fluid. We suggest this is connected to the increased convective efficiency observed in these cases. Our results indicate that 2.5D internally heated convection can be used as a computationally inexpensive test-bed to investigate some aspects of diffusion-free heat transport.</p
‘Shadows of remorse’: Guilt and murder in Ada the Betrayed
No full textThis essay discusses the depiction of violence and remorse in the popular penny serial Ada the Betrayed (1842-3) –the first serial written by James Malcolm Rymer, who would later write the more famous serials Varney the Vampire (1845-7) and The String of Pearls (1846-7). It briefly discusses the rise of penny crime fiction in the 1830s, and the depiction of violence and trauma in the penny serials published in the years immediately preceding Ada, such as Oliver Twiss (1838-9), Ela, the Outcast (1839-41), and The Maniac Father (1842). It then explores how Ada moved away from these in its treatment of the psychology of violence, responding to the moral panic over crime fiction that followed the murder of Lord Russell in 1840, and the role played by the serial in popularising the figure of the remorseful murderer in the popular literary culture of the early Victorian period.</p
Assessing virulence potential in domestically isolated, human pathogenic Vibrio parahaemolyticus
No full textVibrio species are a genus of bacteria that naturally inhabit warm, low-salinity marine, estuarine and freshwater environments. Over 100 species of Vibrio have been described to date, and around 12 of these species can cause disease in humans. This study investigates the presence of vibrios in The Fleet lagoon located in southern UK. The aim of this research was to establish the abundance and type of Vibrio species present in the lagoon and focus on understanding the virulence of pathogenic species that might be present. Sampling took place in The Fleet Lagoon during the summers of 2020, 2021 and 2022 where water, sediment and oyster samples were collected and tested for presence of Vibrio species. From these sampling periods we were able to isolate V. parahaemolyticus from The Fleet lagoon in all three years. We tested V. parahaemolyticus isolates in the in vivo infection model Galleria mellonella to establish the virulence potential of these isolates and assess the risk they may pose to public health. The V. parahaemolyticus isolates demonstrated increased virulence, despite lacking conventional virulence factors associated with infection. This study shows that V. parahaemolyticus present in The Fleet Lagoon could pose a risk to the public health and food safety.</p
Risk-based water pipe failure prediction through machine learning and hydraulic models
No full textFailures in Water Transmission Lines (WTLs) can cause severe disruptions, high repair
costs, and extensive damage to surrounding areas. To mitigate these risks, there is a
growing interest in proactive management through predictive methods. Traditional
methods for identifying high-risk pipelines are often constrained by the scarcity of
available data, especially for large-diameter pipes, making accurate failure prediction
challenging. This study proposes a hybrid approach combining machine learning
techniques with hydraulic modelling to improve the accuracy of pipe failure risk
predictions. Using data from 48 water transmission networks in South Korea, including
pipe intrinsic properties, environmental conditions, operational factors, and failure
history from 2008 to 2023, the study applied tree-based machine learning models
(Random Forest, XGBoost, and CatBoost) along with various data sampling
techniques to predict the probability of pipe failure. XGBoost with class weighting
showed the best performance across key evaluation metrics, including F1-score, F2-
score, AUC-ROC and AUC-PR. A hydraulic model was used to assess the impact of
pipe isolation, quantifying water supply shortages and secondary damages. An
economic analysis was conducted to prioritize pipeline rehabilitation, balancing the
cost of repair with risk reduction. The results demonstrate a cost-effective approach to
risk-based maintenance planning, enabling utilities to allocate resources efficiently for
pipeline rehabilitation while minimizing disruption and water loss.</p
Aggregations of free-living corals facilitate reef expansion at upper mesophotic depth off Poivre Island, Seychelles
No full textFree-living corals on unconsolidated substrates, such as sand and coral rubble, can play a key role in the outward expansion of coral reefs, yet their ecological significance at mesophotic depths remains poorly studied. Here, we present the first detailed documentation of aggregations of free-living corals at mesophotic depths (30–40 m) off Poivre Island, Seychelles, western Indian Ocean. Using manned submersibles and qualitative analysis of high-resolution video transects, we identified different benthic communites. Some of these communities were dominated by assemblages of free-living corals consisting of fungiids and a poritid, with a total of 13 species recorded. These free-living corals contributed substantially to live coral cover (estimated up to 75%) and provided new substrate for reef organisms, facilitating reef growth on unconsolidated sediments. Our findings offer the first direct evidence that free-living coral assemblages can enhance habitat complexity and live coral cover at upper mesophotic depths in the region. Although documented from a single site, our observations highlight the underappreciated ecological importance of free-living corals in deep reef environments and underscore the need for further quantitative research on their role in reef development and resilience.</p
The age imbalance in the duty solicitor scheme: exploring the role of solicitors qualifying examination costs and criminal legal aid policy
No full textThis article investigates the growing age imbalance in the duty solicitor scheme in England and Wales, where the majority of duty solicitors are aged 45 and over, and only 8% are under 34. Drawing on original quantitative data from a pilot survey of 193 aspiring solicitors, it explores whether the cost of the Solicitors Qualifying Examination (SQE) is acting as a financial barrier to specialisation in criminal legal aid (CLA). The findings demonstrate a clear link between the level of SQE fee funding and the perceived ease of entering the CLA sector. Full or substantial funding was widely viewed as an enabler, while lack of funding was consistently identified as a barrier, particularly among working-class respondents and those most committed to specialising in CLA. The article argues that the Ministry of Justice’s failure to implement training grants, despite recommendations from the Independent Criminal Legal Aid Review (CLAIR), is likely contributing to the ageing profile of the duty solicitor workforce. This has serious implications for access to justice and the sustainability of criminal defence provision. The study calls for urgent policy reform to restore generational diversity and ensure the long-term viability of the duty solicitor scheme. description supplied</p
Promoting cooperation in an unequal world: experimental evidence on the role of transparency and punishment
No full textAcross two studies, we examine the role of transparency and peer punishment in promoting cooperation and addressing economic inequality in public good contributions. With global inequality rising and the wealthiest few amassing a greater share of resources, its impact on social cohesion and business environments is increasingly significant. Financial secrecy further compounds these issues by allowing for income and wealth concealment at both societal and organizational levels. Our experimental findings reveal that transparency paired with peer punishment significantly boosts cooperation, particularly among advantaged individuals. In contrast, peer punishment alone proves insufficient to mitigate the adverse effects of inequality without the support of transparency. These results underscore the need for ethical governance structures that incorporate transparency, fairness, and accountability – principles essential for organizations committed to fostering trust and social responsibility in unequal settings.</p