Open Research Exeter - University of Exeter
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Researching Russia with digital trace data
No full textThe Russo-Ukrainian war and the deterioration of the relationship between Russia and the West made the application of traditional social science research methods, such as surveys and fieldwork, difficult for researchers. It is likely that in the foreseeable future students of Russia will have to increasingly rely on the data that can be collected online. Using these data has defined the field of computational social science and has many analytical advantages and come limitations. This paper provides a review of the sources of digital trace data for Russia and of the studies that used them for the analysis of political communication and behaviour, education, labour markets, discrimination, and the Russo-Ukrainian war.</p
An unconditional proof of the abelian equivariant Iwasawa main conjecture and applications
No full textLet p be an odd prime. We give an unconditional proof of the equivariant Iwasawa main conjecture for totally real fields for every admissible one-dimensional p-adic Lie extension whose Galois group has an abelian Sylow p-subgroup. Crucially, this result does not depend on the vanishing of any μ-invariant. As applications, we deduce the Coates--Sinnott conjecture away from its 2-primary part and new cases of the equivariant Tamagawa number conjecture for Tate motives
Advanced Interaction Analysis for Foundation Design and Coastal Cliff Stability
No full textAbstract
Background
Coastal cliff environments present complex geotechnical and structural challenges arising from the combined effects of soil behaviour, wave loading, and progressive cliff erosion. The stability of these areas is critical for the safety and sustainability of coastal infrastructure. Current approaches often fail to fully integrate the coupled effects of hydrodynamic forces, soil response, and structural interaction. This research addresses this gap by developing an integrated analytical and numerical framework capable of simulating fluid-cliff interaction (FCI) and fluid–cliff–foundation interaction (FCFI) and identifying the critical zones in failure and critical construction distance from the cliff crest, beyond which the impact of wave action on foundation performance becomes negligible.
Methodology
A comprehensive mixed-method approach was adopted, combining advanced numerical modelling, experimental investigation, and field data analysis. The research was conducted through three complementary studies:
1)Structure–Soil–Structure Interaction (SSSI): Finite element modelling was used to evaluate how adjacent buildings affect one another’s foundations under varying subgrade reaction modulus (Ks), as outlined in chapter 3.
2)Wave–Cliff Interaction: The mechanisms driving cliff instability under wave impact were examined using an experimental wave flume, supported by three-dimensional numerical models incorporating fluid–structure interaction (FSI) principles. This phase, presented in chapter 4, identified the critical cliff profiles most prone to wave-induced failure.
3)Cliff–Foundation Interaction and Critical Distance: The final component, detailed in chapter 5, developed a methodology to quantify the critical distance from the cliff crest by coupling hydrodynamic loading, soil deformation, and structural response.
Model validation was achieved through comparison with field data from Sidmouth, UK. Parametric and sensitivity analyses using the Random Parameters Method (RPM) and Strength Reduction Method (SRM) were employed to identify the most influential soil and material parameters affecting overall stability.
Key Findings
Incorporating variable subgrade reaction moduli (Ks) in foundation design allows for a more realistic representation of soil–structure interaction. By assigning different Ks values to different regions of the foundation, designers can account for spatial variability in soil stiffness, improving load distribution and minimizing potential settlement or localized overstressing. The experimental and computational results identified soil density, cohesion, and internal friction angle as the dominant parameters influencing cliff retreat and failure modes. Moreover, SSSI exhibited a dual role: it reduced stability in soft soils but contributed positively to stiffness and stress redistribution in hard soils. This finding underscores the importance of site-specific soil characterization in foundation design for coastal regions. The research established that, for the Sidmouth cliff profile examined in this study, wave action significantly amplifies deformation and stress within foundations located within approximately 12 m of the cliff crest, identifying this distance as the critical threshold for safe construction under the given geological and hydrodynamic conditions. Beyond this range, wave-induced and hydrodynamic effects were found to diminish markedly.
Contributions
This thesis delivers a novel, validated, and adaptable framework that integrates SSI, SSSI, FSI, and FCFI within a unified analysis platform. The key contributions include:
•Establishing a quantitative critical distance from the cliff crest to guide safe building placement.
•Demonstrating the interactive effects of wave energy, cliff morphology, and soil–foundation behaviour.
•Introducing an optimised design approach using variable subgrade stiffness to enhance the accuracy of foundation modelling.
•Providing a scientific basis for coastal planning and setback policy formulation.
Collectively, the findings advance understanding of coupled geotechnical–hydrodynamic–structural interactions in coastal environments. The developed framework supports the design of resilient coastal infrastructure, promotes sustainable urban planning, and informs evidence-based coastal management strategies for erosion-prone regions.</p
Harmonising Social Considerations in Firms Transitioning to a Circular Economy
No full textThis thesis investigates how organisations develop capabilities for integrating social considerations within circular economy business model transitions - a dimension systematically marginalised in circular economy scholarship despite determining transformation success through stakeholder acceptance, workforce engagement, and community support. Through qualitative investigation of three multinational enterprises at different circular economy maturity stages (nascent, emergent, mature) within UK automotive and related sectors, the research addresses three questions: how organisations incorporate social considerations into business model design, what drivers and barriers influence social value integration, and how organisations harmonise economic, environmental, and social dimensions.
The research employs critical realist philosophy with abductive methodology, enabling theoretical development when empirical patterns exceeded explanation by existing frameworks. The Gioia methodology provided systematic analytical progression from participant accounts through conceptual themes to theoretical contributions, while cross-maturity comparison generated insights into capability development trajectories.
Three interconnected theoretical contributions emerge. First, the extended dynamic capabilities framework proposes "reacting" as a fourth capability alongside Teece's sensing-seizing-reconfiguring triad, addressing how organisations respond to unexpected stakeholder pressures while generating learning that enhances systematic capability development. The reacting capability develops progressively over time while operationally enabling rapid response to unanticipated events - addressing temporal complexity that existing frameworks inadequately accommodate. Second, the multi-level social value integration framework demonstrates how organisations progressively embed social considerations through operational, strategic, and ecosystem levels, each requiring distinct capabilities while building upon previous foundations. Third, the nested stakeholder development framework reveals how stakeholder engagement capabilities develop cumulatively from inner through middle to outer circles, with outer circle effectiveness depending fundamentally on inner circle capability strength.
The findings contribute to circular economy literature by addressing systematic marginalisation of social dimensions, to dynamic capabilities theory by extending theoretical frameworks for complex transformation contexts, and to sustainability science by bridging the persistent gap between transformation aspirations and organisational realities. Practical implications provide capability assessment frameworks and implementation guidance for organisations navigating circular economy transitions.</p
Understanding immune priming in Pacific oysters: A multi-omics exploration of transcriptomic, epigenetic and microbiome regulation
No full textAquaculture has a fundamental role to play in global food security, given the limitations for increase of captures from global fisheries and the pressures they pose on the natural environment. Infectious disease remains an important limitation for the aquaculture industry both because it is financially costly and contributes towards poor animal welfare. For molluscs, widespread mass-mortalities of Pacific oysters (Magallana gigas) have occurred in recent years linked to infection with the bacterial pathogen Vibrio aestuarianus. Disease in farmed oysters is difficult to prevent or to treat and, in this context, immune priming has been proposed as a method to increase resistance to disease, and has been reported to be effective for viral pathogens. However, it is unknown whether an immune response can be primed in oysters to provide protection against Vibrio aestuarianus upon secondary challenge. This thesis aimed to address this knowledge gap and explored the hypothesis that epigenetic and microbiome processes are involved in sustaining long-lasting immune system memory.
In order to identify a period of DNA methylation reprogramming, and therefore a candidate window of epigenome malleability, Pacific oyster embryos were exposed to the methylation inhibitor 5-azacytidine at different temporal intervals throughout early development (Chapter 2). A period of methylation inhibitor sensitivity was observed up to approximately 11 hours post fertilisation, which is indicative of a window of methylome reprogramming. Further periods of reprogramming and/or epigenetic sensitivity may exist after this window, but their presence and precise timing was not explored.
Pacific oysters were primed with heat-inactivated Vibrio aestuarianus via 24-hour bath exposure at either the larval or young spat stage, then challenged with the non-attenuated form of the pathogen at six months old. A multi-omics approach involving RNA-Seq, 16S amplicon sequencing and whole genome bisulphite sequencing was utilised to interrogate whether immune priming resulted in long-lasting molecular alterations to the oyster transcriptome, microbiome and epigenome (Chapters 3-5). For naïve oysters, transcriptomic analysis evidenced that Vibrio aestuarianus had an immunosuppressant effect on 6-month-old oyster spat, despite high survival rates and no significant alterations in oyster microbiota suggesting spat were not susceptible to disease. Immune priming at either the larval or young spat stage resulted in lasting alterations in the oyster transcriptome, microbiome and epigenome that were sustained for up to five months after the priming took place. Lasting transcriptional alterations were identified in pathways including complement, protein modification and phagocytosis, with upregulation of these pathways suggesting faster pathogen recognition upon challenge. The oyster transcriptome, microbiome and epigenome appeared to remain malleable after metamorphosis, although larval priming appeared to be more beneficial in terms of increasing within-sample microbial diversity.
Together, this thesis demonstrates that acquired immunity can be primed in Pacific oysters against Vibrio aestuarianus at either the larval or spat stage and suggests that epigenetics may be responsible for the continued alteration of transcriptional and microbiome regulation after priming. However, it remains unclear how long this acquired pathogen memory may persist for and whether priming during a window of epigenome malleability will enhance adult survival against the virulent pathogen. Overall, this work highlights the potential to utilise sensitive windows during early life to manipulate the microbiome and epigenome in order to induce lasting memory for use in disease control within bivalve molluscs. Future research is required to clarify the precise causative mechanisms of the effects seen, whether transgenerational immunological memory can be primed against Vibrio aestuarianus, and evaluate the feasibility of this approach for building pathogen resistance within invertebrate aquaculture settings.</p
Harmonising definitions of multiple long term conditions for inflammation research: a co-production approach
No full textObjectiveInflammation is implicated in many chronic diseases, but its role in driving multiple long-term conditions (MLTCs) remains unclear. The InflAIM programme aims to explore this potential link. Existing MLTC codelists are valuable but have not been designed for inflammation-focused research and often lack harmonisation across coding systems. This work aimed to develop a transparent, co-produced MLTC framework with harmonised codelists for epidemiological research, focusing on inflammatory conditions within the InflAIM programme.ResultsUsing a systematic, co-produced approach, we combined literature review, clinical consensus, and patient input. From 8 sources, 363 candidate conditions were identified, refined to 60 validated MLTCs. Patients informed terminology and diagnostic experiences. Codelists were drawn from CALIBER (43), HDR UK Phenotype Library (4), MULTIPLY (8), with 7 developed de novo. Harmonisation covered Read v2, SNOMED CT, and Medcodeids. Quality assurance excluded 16.5% of codes and resolved 92 overlaps.We produced harmonised codelists for 60 MLTCs, comprising 7,426 validated MedCodeids. Clinical consensus identified 17 conditions with significant inflammatory components. Additional lists were developed for autoimmune and infectious diseases to support inflammation-focused analyses. This framework extends existing resources to meet the needs of inflammation-focused research, offering a transparent, harmonised, and patient-informed foundation for the InflAIM programme.</p
Quantification of droplet aerosol generation during phacoemulsification and pars plana vitrectomy
No full textIntroductionIntraocular procedures such as phacoemulsification and pars plana vitrectomy (PPV) may generate fine droplet aerosols that are relevant to infection control, particularly in the context of SARS-CoV-2. Data on aerosol production during cataract and vitrectomy surgery, especially in human tissue and with different wound constructions, remain limited. This study used a high-sensitivity optical particle spectrometer to quantify droplet aerosols (0.12-8.00 μm in diameter) generated during phacoemulsification in cadaveric human eyes with 2.2 mm and 2.75 mm corneal incisions, to assess whether hydroxypropyl methylcellulose (HPMC) reduces aerosol production, and to measure aerosol generation during individual steps of PPV.MethodsTests were performed on one model eye and two human cadaveric eyes. A printed optical particle spectrometer (POPS) was used to measure droplet aerosol generation during phacoemulsification through 2.2 mm and 2.75 mm main corneal incisions, with and without HPMC coating, and during predefined stages of 23-gauge PPV. Particle number concentration (PNC, particles cm⁻³) was recorded each second and summarised as mean PNC for each condition.ResultsIn this small series, mean PNC during phacoemulsification without HPMC appeared to be higher with 2.75 mm incisions than with 2.2 mm incisions, and counts of particles >1 μm in diameter were also greater. Application of HPMC was associated with reduced aerosol counts. The maximum measured mean PNC without HPMC for 2.2 mm corneal incisions was 88 cm⁻³, which fell to 66 cm⁻³ with HPMC (pConclusionTo our knowledge, this is the first study to use whole cadaveric human eyes in combination with a high-sensitivity optical particle spectrometer to quantify airborne particle number and size during phacoemulsification and PPV. In this model, droplet aerosol production during cataract surgery appeared lower with 2.2 mm incisions and with HPMC coating of the cornea. Droplet aerosols may be generated during vitrectomy when air infusion is delivered through a leaking trocar valve, highlighting the importance of port integrity.</p
Natural language processing of biomedical text to map and prioritize protein–disease associations in HFpEF
No full textThe validation of promising clinical biomarkers, molecular mechanisms, and novel drug targets in cardiovascular disease (CVD) is hindered by a vast and fragmented biomedical literature, which now exceeds 38 million publications indexed in PubMed. To address the central challenge of navigating and synthesizing a huge fragmented biomedical literature base, we applied our validated machine learning–based text-mining algorithm containing natural language processing (NLP) and incorporated this into a ValIdated Text-mining using Advanced Language model (VITAL) as a complementary framework. Using this approach, we analyzed more than 38 million PubMed abstracts and identified over 5.5 million relevant to six major CVD groups. These curated data then enabled a deep-dive case study on heart failure with preserved ejection fraction (HFpEF). Our computational framework systematically queried, quantified, mapped, and prioritized protein–disease associations, confirming established CVD biomarkers, such as BNP, troponin-I, galectin-3, and renin, and revealing novel protein signatures with potential diagnostic and therapeutic relevance. Ischemic heart disease (IHD, heart attacks), cardiomyopathy (CM, leading to heart failure), and cerebrovascular accidents (CVA, strokes and brain hemorrhages) exhibited the highest protein attribution densities and overlap, suggesting shared molecular pathways. Using HFpEF as a focused case study, our framework identified 5124 proteins associated with this condition, 4879 of which were shared across its major comorbidities (aging, type 2 diabetes/obesity, hypertension, and hyperlipidemia). Additionally, 4991 proteins were co-shared across key pathological mechanisms, including inflammation, mitochondrial dysfunction, and fibrosis, implicating convergent biological networks spanning these domains. To further characterize and prioritize these molecular associations, we performed a series of data science-driven analyses involving HFpEF-associated proteins. The top computationally ranked HFpEF protein candidates were the same top ranked proteins in the comorbidity-domains and in the pathology-domains suggesting that these proteins are important drivers with convergent molecular networks underlying HFpEF. Cross-referencing and validating top-ranked computational HFpEF protein candidates with clinical myocardial and extracardiac biopsy data from HFpEF patients and corresponding controls revealed that most of these proteins are predominantly expressed in the liver, pancreas, adipose tissue, and lymph nodes, rather than in cardiac tissue. This finding supports the emerging concept that HFpEF is fundamentally a multisystemic disorder mediated by inter-organ signaling rather than a disease confined to the heart. Our computational study demonstrates the capacity of text mining to annotate, integrate, and prioritize protein-disease relationships from large-scale textual data, thereby providing a complementary framework to traditional omics approaches for biomarker discovery and drug target identification in CVDs.</p
Reverse chronology quota record screening for realist synthesis: Fostering causally rich extrapolations with a diverse and contemporaneous sample of literature
No full textIdentifying studies for inclusion in realist syntheses using title and abstract screening is challenging given the need to unearth explanatory insights to build context–mechanism–outcome configurations. Such insights may only be uncovered through full-text paper reading. To address this issue, a novel approach for identifying studies has been developed called Reverse Chronology Quota Record Screening (RCQRS). Results of database searches are screened in reverse chronology, and in stages, to fill quotas matching the requirements of the review. RCQRS may be beneficial in any of the following circumstances: (a) the timeframe to complete the synthesis is short; (b) the scope of inquiry is not fully defined, (c) the availability of suitable literature is beyond the screening capacity of the reviewers; or (d) the availability of literature is sparse and reviewers seek to extrapolate insights from other areas. In contrast to RCQRS, exhaustive title and abstract screening (i.e., screening entire database results) may hamper study selection due to being overwhelming in volume and time-intensive, resulting in a causally thin cohort of papers for analysis. RCQRS used in stages, and in conjunction with other search strategies (e.g., hand searching, backward citation tracking, and expert solicitation) can support creative, robust analytical insights with causally rich extrapolations. Using the Horizon-EU funded SERENITY study on deprescribing in palliative care as a case example, the benefits and limitations of RCQRS are explored. Finally, a checklist template is offered for teams who wish to reflect on, and transparently report, the use of RCQRS in their realist synthesis.</p
The effectiveness of prehabilitation on post-operative recovery from lumbar spinal stenosis surgery - a systematic review and intervention component analysis.
No full textObjective: To evaluate prehabilitation interventions evaluated in randomised controlled trials for people undergoing lumbar spinal stenosis surgery and determine which individual intervention components are associated with successful interventions. Data sources: English language papers from 2011 until December 2025 from PubMed, Cumulative Index of Nursing and Allied Health, Scopus and Web of Science. Review methods: We searched for randomised controlled trials comparing prehabilitation to other non-active interventions for people undergoing surgery for lumbar spinal stenosis. Two authors independently screened, selected and performed quality assessments of the studies. Relevant study details were extracted, tabulated and synthesised using intervention component analysis. Results: Nine papers describing five randomised control trials involving 466 participants and 28 outcomes measured pre- and/or post-surgery were found. Overall, the interventions consisted of 47 individual components. Fifteen of these components (including psychological/behavioural approaches, and cardiovascular, strength and trunk/core exercise) featured in successful interventions that resulted in greater improvement in 16 outcomes (including back pain, disability, walking and hospital stay) in prehabilitation compared to usual care participants. The results of further evaluation of individual outcomes at each time point was inconsistent and unreliable. Conclusion: Only five small trials of low-to-moderate quality report common outcomes at similar timepoints. There is high uncertainty regarding the importance of individual intervention components in successful prehabilitation interventions for people undergoing lumbar spinal stenosis surgery. [PROSPERO registration number: CRD42025645253, https://www.crd.york.ac.uk/PROSPERO/view/CRD42025645253]</p