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Bacterial genotype and infection host shape the potential for cheating and evolution of virulence during passage in Bacillus thuringiensis.
No full textUnderstanding the evolution of pathogen host range is a challenging problem but one that is important for emerging infections and for biocontrol. Theory predicts that sequential selection in multiple host species should select for broad host range. Using two genotypes of B. thuringiensis we tested whether selection in alternating host environments would produce bacteria with increased virulence in both hosts, relative to bacteria passaged in single host species (fall armyworm, Spodoptera frugiperda or diamondback moth, Plutella xylostella). Since the Cry toxins of B. thuringiensis are public goods that benefit groups of bacteria, not individual cells, we employed a passage design which provided reproductive benefits to groups of pathogens, based on infectivity. Passage of one bacterial genotype (Bt morrisoni) led to the loss of virulence, while the second genotype (Bt galleriae) evolved virulence that was dependent on selection treatment. In contrast to expectation, selection in P. xylostella produced lineages with increases in virulence in both hosts; selection in S. frugiperda led to very low virulence and the alternating host treatment produced intermediate levels of virulence. Modest increases in virulence were accompanied by a reduction in fitness, consistent with a cost of increased investment in virulence factors. In contrast, infection in S. frugiperda selected for cheaters that had reduced investment in Cry toxins and high competitive fitness within hosts. In conclusion, the selection favouring cheaters depended strongly on both host species and bacterial genotype. Importantly, the host (P. xylostella) that favoured cooperation produced mutants with gains in virulence across multiple hosts.</p
Sleep, steps, and screens: between- and within-person effects of digital markers of daily life behaviors on smartphone-based assessments of cognitive functioning in depression
No full textCognitive impairment represents a core feature of major depressive disorder (MDD), often persisting after mood symptoms remit and not addressed by usual antidepressant treatments. Despite its relevance, cognition is typically assessed with infrequent tests in clinical settings, overlooking its contextual nature. Smartphones and wearables enable ecologically valid, repeated measurements of cognition and daily life behaviors that may impact it. We examined whether sleep duration, step count, and smartphone screen time are associated with cognitive functioning in MDD.We conducted secondary analyses of RADAR-MDD, a multicenter study following individuals with recurrent MDD. Cognitive functioning – self-reported and performance-based – was assessed with the THINC-it® app. Sleep duration and step count were measured with Fitbit devices, and screen time with the RADAR-Base app. Cognitive assessments (outcomes) were linked to behavioral measures (predictors) from the day of and the day preceding each assessment. Two-level multilevel models estimated between-person (differences in participant means) and within-person (deviations from participant means) effects. The sample included 502 participants, further subdivided by behavior–cognitive outcome pair.For performance-based cognitive assessments, positive associations at the between-person level were found for step count (β = 0.104, SE = 0.031, p Our findings illustrate that smartphones and wearables can collect meaningful daily life data of MDD patients that can be used to support cognitive health. Step count emerges as a promising behavioral target as it is simple to track and is correlated with better cognitive outcomes.</p
Time as possibility, scale as power: entanglement and the emergence of international imaginaries of democratic confederalism and Neo-Ottomanism in the Kurdish-Turkish Conflict
No full textEMBARGOED – expected end date 11.02.2028</p
Can micro-behaviours be used for graph comprehension assessment?
No full textNo description supplied</p
Locomotory behaviour in a wild ground beetle is consistent within individuals and depends on temperature and humidity
No full textLocomotion is central to the lives of animals. Fluctuations in temperature and humidity can influence animal locomotion, particularly in ectotherms where internal and external temperatures are generally more closely coupled, despite the buffering effects of behavioural thermoregulation. The advances in radiotelemetry have permitted fine-scale movement data to be obtained under natural conditions on smaller animals. Despite their ubiquity, insect locomotion and its dependence on temperature and humidity have been little explored in the field. In this study, radiotelemetry was used to track 52 flightless ground beetles, Carabus hortensis, in a temperate forest in Northern Germany, recording 3870 beetle locations. The distances walked by beetles were dependent on temperature and relative humidity, with individuals moving farther at intermediate temperatures and extreme (high and low) humidities. Furthermore, individuals differed consistently in the distances they walked despite fluctuating temperature and humidity, showing that locomotion is a personality trait in this species under fluctuating field conditions. Results indicate that locomotory behaviour is a response to varying environmental conditions and a personality trait with potential implications on individual survival and reproductive success.</p
Advances in soft porous lubrication
No full textThis dissertation examines the mechanisms, underlying principles, and practical applications of Exporo-hydrodynamic (XPHD) lubrication, a soft, porous lubrication approach inspired by biologicaljoint function. It presents a structured, multi-phase study which leads to the creation and experimental validation of the first theoretical model of XPHD journal bearing.XPHD lubrication operates by generating fluid pressure within a compressed, fluid-saturated porous layer, a mechanism that contrasts sharply with classical hydrodynamic lubrication, which depends on rigid surfaces and converging geometries to build pressure. A detailed literature review and theoretical assessment revealed limitations in current XPHD research, particularly regarding performance at low sliding speeds and the narrow focus on open-cell foams as the primary material choice.A comprehensive friction performance study revealed that woven fibrous materials significantly outperform foam-based counterparts, achieving friction coefficients as low as 0.02 with high durability under dry and wet conditions. These findings led to the selection of woven materials for all subsequent phases.The mechanism was then validated at ultra-low sliding speeds (0.06 m/s) using a custom-designed and built inclined slider rig, showing strong agreement with Pascovici’s 1D XPHD model. This low-speed validation provided critical groundwork for conformal systems modelling.A new theoretical model for XPHD journal bearings was introduced by reformulating the Reynolds equation in cylindrical coordinates and integrating it with Darcy’s law and the Carman–Kozeny relationship. Experimental validation using a purpose-built test rig showed strong alignment between predicted and measured pressure profiles across different eccentricities and materials.Key contributions include:- Introducing woven fibrous materials as high-performance XPHD substrates.- Demonstrating XPHD pressure generation at joint-like speeds.- Extending XPHD theory to cylindrical journal bearings.- Developing the first experimental rig dedicated to XPHD journal bearing testing.Limitations such as simplified flow modelling, measurement variability, and the absence of coupled fluid-solid simulations are acknowledged, with future directions proposed in dynamic loading, wear studies, and smart system integration.</p
Simulation-enabled physically plausible data augmentation for wearable IMU-based Human Activity Recognition
No full textWearable devices equipped with inertial measurement units (IMUs) are widely used for human activity recognition (HAR), but effective HAR model training requires extensive annotated data-sets, which are costly and challenging to collect. Signal transformation-based data augmentation (STDA) methods, adapted by common time-series augmentation techniques, aim to address this data scarcity. However, they often lack domain-specific realism and physical plausibility, limiting their effectiveness. Meanwhile, advances in video-based human pose estimation have made virtual IMU simulation increasingly accessible, creating promising opportunities for simulation-based augmentation via systematic parameter modifications. However, existing simulation approaches still face a substantial fidelity gap between simulated and real IMU signals, which limits their practical use. This thesis argues that PPDAs realised through physics-based virtual IMU simulation yield more effective data for training HAR models than conventional STDAs, provided the fidelity gap is addressed. To demonstrate this, we first explore simulation-based augmentations through a digit-drawing gesture recognition task, revealing promising benefits but also highlighting the fidelity gap as a critical limitation. To address this limitation, we introduce WIMUSim, a differentiable simulation framework designed to generate high-fidelity virtual IMU data by precise parameter identification through gradient descent, using concurrently recorded wearable IMU and motion data. Leveraging WIMUSim, we propose PPDA methods and systematically evaluate their effectiveness using three public datasets (REALDISP, REALWORLD, MM-Fit). Our evaluations in fully supervised learning scenarios demonstrate that PPDA enhances HAR classification accuracy and reduces the number of subjects required for effective model training compared to STDAs. Extending PPDA into self-supervised contrastive learning, we observe substantial improvements in downstream HAR performance and label efficiency. Collectively, these results support the central thesis that simulation-enabled physically plausible data augmentations provide more effective data for HAR than conventional STDAs. This data-centric approach incorporates domain knowledge into augmentations to mitigate data collection burdens and enables efficient and ethically responsible use of human-subject data, particularly relevant in contexts where data collection is especially challenging, such as research involving vulnerable populations. </p
Social context in misophonia: does misophonia impact social judgements (& do social judgements impact misophonia)?
No full textMisophonia is a sound sensitivity disorder characterised by strong negative reactions to specific sounds (e.g., chewing). Previous studies have suggested a link between social judgements and misophonia, in that misophonia arises not simply from auditory/acoustic processing but also from how an individual interprets the meaning of trigger sounds within their social world. In our study, we experimentally manipulated our participants’ social perceptions of various people making sounds, to explore its impact on misophonia. In reverse, we also examined how sounds influenced misophonics’ social evaluations of those same individuals, revealing a bidirectional relationship between sound intolerance and social cognition. We found that social judgements affected the aversiveness of trigger sounds, since sounds were judged as more aversive if they came from people who had been depicted as socially negative. We also found that—when no sounds were present—social judgements made by people with misophonia were entirely typical (i.e., no different from controls). Finally, misophonics perceived people as less pleasant if they produced noisy eating sounds, and these differences were especially apparent if prior perceptions of those people were positive. Together, our findings suggest that unpleasant sounds are harder to tolerate for misophonics when they come from unlikeable individuals, and that even highly likeable people can be judged more harshly if they produce trigger sounds.</p
Exploring and harnessing social identity processes to enhance international students’ mental health in the United Kingdom
No full textEMBARGOED - expected end date 19.01.2028</p
Making victims, making offenders: county lines, modern slavery and the criminal law
No full text‘County lines’ drug supply has grown into a powerful cultural, criminological and political concern in the UK. In recent years, the criminal law has been mobilised, through the use of anti-trafficking and modern slavery legislation, to increase punishments for those found responsible for the exploitation of children. In this paper, I use insights from actor-network theory (ANT) to explore the first test case in which judges authorised this strategic repurposing of legislation. By opening up the ‘black box’ of legal thinking, my aim is to both scrutinise the technical forms of practice that make up criminal lawmaking and to situate such practices within a broader cultural apparatus of blame.</p