Open Research Exeter - University of Exeter
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Skin and gill microbiome profiles and network structures in farmed tilapia (Oreochromis niloticus) and their relationships with health conditions
No full textBackground: Tilapia is one of the most popular finfish in aquaculture, but various emerging infectious diseases are limiting the growth of the tilapia aquaculture industry globally. The external mucosal microbiomes of fish act as a first line of defence for maintaining host health. However, how skin and gill microbiomes differ between healthy and naturally infected tilapia remains poorly understood. Here, we employed 16S rRNA and 18S rRNA high-throughput metabarcoding to characterise the microbiome of tilapia skin, gills, and water from ponds reported with diseased and non-diseased conditions, and to investigate signatures of microbial dysbiosis related to health conditions. Results: Microbial diversity varied significantly across different sample types (gill, skin and pond water) and geographical locations. Skin and gill microbiomes from reported non-diseased conditions differed in the presence of the commensal genus Cetobacterium, while diseased gill-skin were enriched with pathogenic genera including Flavobacterium, Aeromonas, Vibrio, Vogesella, and Klebsiella. Additionally, the relative abundance of diatom Cyclotella in pond water under diseased conditions appeared to be almost double that of non-diseased pond water, albeit this was statistically non-significant. Cetobacterium formed a core component of the bacterial genera in the non-diseased gill and skin microbiome. In contrast, Aeromonas formed a core component of the core microbiome in the diseased gill and skin microbiomes. Analysis of the microbial co-occurrence network in the diseased skin and gill found it to be relatively less complex compared with these tissues in the non-diseased state. Conclusions: The findings show that the tilapia microbiome differs across the skin and gill tissue surfaces, and from the pond waters in which they are cultured. In reported diseased cases, these microbiomes show enrichment of potential pathogenic genera and less complex microbial co-occurrence networks, which may be used as an indicator of microbial dysbiosis in aquaculture systems. Understanding how these alterations may be used to predict potential disease outbreaks requires an understanding of the functional impacts of the changes in the microbial assemblages, allowing for timely interventions to mitigate the impacts of disease in the aquaculture system.</p
Light-matter interactions in 3D chiral plasmonic nanostructures with geometric spin-orbit hybridization
No full textChirality, either induced by geometry or motion, plays a pivotal role in optics and photonics. The interaction of light and matter lacking mirror symmetry induces intriguing optical phenomena such as circular dichroism (CD) and enhanced optical chirality density, inspiring various applications ranging from polarization control, optical sensing, and enantioselective detection to chiral light emission management and photocatalysis. Inspired by the spin and orbital angular momentum of light, we present a systematic framework that classifies and integrates chiral nanostructures formed through the spin and orbital motion of two-dimensional (2D) geometries with mirror symmetry. By systematically analyzing geometric asymmetry and rotational speed, we control both far-field CD and near-field optical chirality density, uncovering distinct yet complementary chiral responses arising from spin-orbit geometry. Inspired by spin-orbit interactions in light, we introduce and implement a geometric spin-orbit hybridization framework to design chiral nanostructures, demonstrating the potential for practical applications, including polarization-sensitive photothermal detection and plasmonic nano-needles with uniform and strong chirality density. Our findings establish a versatile platform for engineering chiral nanostructures, shedding light on advanced applications in nanophotonics and chiral light-matter interactions.</p
Updating a clinical prediction model for identifying monogenic diabetes to include both clinical features and biomarkers.
No full textOBJECTIVE: Selecting appropriate individuals for monogenic diabetes genetic testing is challenging. We aimed to develop a new probability calculator, integrating clinical features and biomarkers, to aid identification of monogenic diabetes. RESEARCH DESIGN AND METHODS: We developed two prediction models (for early-insulin-treated, proxy for type 1 diabetes; and not-early-insulin-treated patients, proxy for type 2 diabetes) using a Bayesian recalibration mixture model approach. We used case-control data (monogenic diabetes = 594, non-monogenic diabetes = 597) for initial model development (clinical features only) and recalibrated to population data (Using pharmacogeNetics to Improve Treatment in Early-onset Diabetes [UNITED] study, n = 1,299) including biomarkers (C-peptide and islet autoantibodies). We externally validated the calculator in an independent population-based cohort (n = 1,025). RESULTS: For early-insulin-treated individuals, the model incorporating biomarkers improved discrimination over using clinical features only (Receiver Operating Characteristic Area Under the Curve [ROCAUC] 0.98 [95% credible interval [CrI] 0.95-0.98] vs. 0.80 [95% CrI 0.71-0.82], P </p
Bidirectional Prototype-Guided Consistency Constraint for Semi-Supervised Fetal Ultrasound Image Segmentation
No full textFetal ultrasound (US) image segmentation plays an important role in fetal development assessment, maternal pregnancy management, and intrauterine surgery planning. However, obtaining large-scale, accurately annotated fetal US imaging data is time-consuming and labor-intensive, posing challenges to the application of deep learning in this field. To address this challenge, we propose a semi-supervised fetal US image segmentation method based on bidirectional prototype-guided consistency constraint (BiPCC). BiPCC utilizes the prototype to bridge labeled and unlabeled data and establishes interaction between them. Specifically, the model generates pseudo-labels using prototypes from labeled data and then utilizes these pseudo-labels to generate pseudo-prototypes for segmenting the labeled data inversely, thereby achieving bidirectional consistency. Additionally, uncertainty-based cross-supervision is incorporated to provide additional supervision signals, thereby enhancing the quality of pseudo-labels. Extensive experiments on two fetal US datasets demonstrate that BiPCC outperforms state-of-the-art methods for semi-supervised fetal US segmentation. Furthermore, experimental results on two additional medical segmentation datasets exhibit BiPCC's outstanding generalization capability for diverse medical image segmentation tasks. Our proposed method offers a novel insight for semi-supervised fetal US image segmentation and holds promise for further advancing the development of intelligent healthcare.</p
“So, what’s the actual strengths of having ADHD?”: Exploring resilience factors that support adolescent girls with ADHD to experience success at school.
No full textThe estimated prevalence of attention deficit hyperactivity disorder (ADHD) in children and young people (CYP) in the UK is 5% (NHS England, 2024; Sayal et al., 2018). While there is evidence to suggest that ADHD is more likely to be diagnosed in boys than girls, this gap is lessening with increased awareness of gender differences in ADHD presentation (Hinshaw et al., 2022; Young et al., 2020). Despite this, evidence on the experiences of girls with ADHD is under-researched, with much of the previous literature exploring ADHD focusing on a deficit model (Climie & Mastoras, 2015; Edwards, 2022; Krtkova et al., 2022), with a lack of research directly considering what factors contribute to success. This research aimed to consider what resilience factors contribute to success at school for girls with ADHD. A multisystemic theory of resilience is drawn upon to support the exploration of how personal, relational and contextual resilience factors dynamically interact and contribute to how girls can overcome the challenges of ADHD to thrive at school (Ungar, 2021).
This research adopted a two-phase design. In phase one, five adolescent girls, attending mainstream secondary schools in England, completed a semi-structured creative interview, using an adapted tree of life to explore their experiences and views of school. Using a thematic narrative approach, threads across each story identified that peer relationships, supportive school staff, identity development and personal strengths of creativity and perseverance played a significant role in their resilience and school success. In addition, gendered expectations, lack of understanding of ADHD in themselves and challenges related to stigma contributed to the barriers they experienced.
In phase two, seven TAs who work at mainstream secondary schools completed a semi-structured interview to explore their experiences of supporting girls with ADHD and resilience factors contributing to girls with ADHD's success at school. A reflexive thematic analysis (RTA) was used to identify themes across interviews. Findings from phase two outline that TAs identified the importance of their role in building relationships, advocating and supporting in recognising and promoting strengths and self-esteem in girls with ADHD. Systemic barriers of limited training, lack of understanding of gender differences in ADHD and the rigidity of school systems contributed to barriers to both TAs themselves and girls with ADHD.
Considering both phases together, these findings highlight the complexity of resilience factors for girls with ADHD, suggesting the need for a holistic, relational and identity-affirming environment to support girls with ADHD at school. In addition, these findings evidence the importance of further exploring the experiences of girls with ADHD and utilising a strengths-based approach to identifying factors that contribute to their success at school. The lack of recognition of ADHD in girls, the importance of peer, family and education staff relationships in promoting self-esteem is discussed, considering how these factors contribute to the academic, social and emotional experiences of girls with ADHD at school. The research concludes with implications and recommendations for educational psychology practice and school.</p
The Ultrastructure of the Articular Cartilage and its Biomechanics
No full textThe biomechanical properties of articular cartilage (AC) arise from a complex environment in which hierarchically organised collagen networks within the extracellular matrix (ECM) interact with a proteoglycan-rich interstitial fluid. However, how collagen fibrils reorganise under load across the tissue, and how these behaviours vary with anatomical context or disease, remains poorly understood. This gap stems from the challenge of simultaneously capturing fine-scale (sub-micron) collagen organisation and the collective mechanical responses of cartilage zones (micron scale) under near-physiological conditions, which is essential for understanding degenerative conditions such as osteoarthritis (OA).
Upon reviewing the literature, recent advances in polarisation-resolved second harmonic generation (pSHG) microscopy have demonstrated the ability to capture the hierarchical organisation of collagen fibrils at sub-micron resolution, as well as intrafibrillar molecular alignment, offering a label-free, depth-resolved imaging for collagen tissue (Chapter 2). Building on these capabilities, this thesis presents the integration of pSHG with in-situ mechanical loading to quantify depth-resolved fibril organisation and zonal-specific mechanical responses for the first time (Chapter 3). This work further introduces a novel multimodal correlative imaging pipeline, combining pSHG with histology, quantitative backscattered electron imaging (qBEI) and micro-computed tomography (µ-CT) in murine joints. This integrated approach enabled the first direct correlation between collagen organisation, mineralisation, and bone-cartilage architecture, revealing previously unreported compartment-specific differences that demonstrate how anatomical context governs cartilage zonal structure and mechanical function (Chapters 4-5). Building on this foundation, the progression of OA was monitored in preclinical models to detect early alterations preceding visible AC degeneration, thereby identifying quantitative biomarkers for early disease detection (Chapter 6).
Collectively, this thesis addressed key challenges in characterising the ultrastructure and mechanics of collagen fibrils, offering a transformative approach for the early diagnosis of OA and providing valuable insights for the development of tissue-engineered cartilage. By advancing the understanding of collagen fibril architecture and biomechanics, this approach holds considerable promise for improving the durability and functional performance of engineered cartilage, ultimately supporting the development of more effective regenerative therapies for patients with OA. Furthermore, by identifying early-stage biomarkers associated with AC degeneration, this thesis contributes to a potential shift in OA management from late-stage intervention toward proactive disease prevention, thereby reducing reliance on joint replacement surgery.</p
Issues of Sustainability and Resilience in UNESCO Biosphere Reserves Governance: A Legal Evaluation
No full textThis article explores the potential of UNESCO's Statutory Framework of the World Network of Biosphere Reserves as an effective adaptive legal instrument for enhancing environmental governance. It examines the framework of Biosphere Reserves (BRs), focusing on interactions with local communities to explore place-based outcomes in sustainable development and biodiversity conservation. The flexibility of soft law frameworks associated with BRs enables an adaptive response to local contexts. It fosters community collaboration in environmental management, contrasting with rigid conventional frameworks that often struggle with adaptability and local relevance. BRs emphasise collaboration between stakeholders and demonstrate a pathway for achieving sustainable development and biodiversity conservation effectively. This study contributes to the discourse within international environmental law by highlighting the importance of integrating more adaptive legal mechanisms, such as the BR Framework, alongside typical hard law instruments. As the global community faces increasingly complex environmental and climate challenges, findings underscore the need for approaches that leverage adaptability, indicating that BRs serve as models for enhancing local governance in sustainability and resilience. This research suggests that the effectiveness of international environmental governance depends on embracing flexible, adaptive, and community-oriented frameworks, thereby prompting a re-evaluation of existing hard law in the pursuit of comprehensive environmental governance.</p
Work‐related technology use during nonwork time and its consequences: A resource‐oriented perspective
No full textEmployees increasingly use information and communication technologies (i.e., ICTs) to work during nonwork time (e.g., responding to e‐mails, taking calls), even when not contractually required. Despite potential work‐related benefits, voluntary work‐related ICT use can affect employees' recovery and well‐being. Drawing on the conservation of resources theory and self‐regulation, we argue that engaging in voluntary ICT use during workday evenings is a work‐related resource investment, requiring self‐regulatory resources. Consequently, employees lack such resources to regulate their attention away from work, thus experiencing reduced psychological detachment. This, in turn, can impede employees' ability to engage in mood repair regarding affective well‐being at bedtime and the following morning. We propose that employees can alleviate this process through substituting and replacing self‐regulatory resources by having control over their evening and good sleep quality, respectively. Conducting a daily diary study over five consecutive workdays and following mornings with 187 participants, we found negative indirect effects of voluntary ICT use on affective well‐being the following morning, via reduced psychological detachment. Feeling in control during nonwork time and sleep quality mitigated these effects. Our study contributes to the conceptual understanding of voluntary ICT use and how this behaviour can be managed more actively by individuals
Heterogeneous graph neural networks enhance pressure estimation in water distribution networks
No full textPressure estimation is crucial for efficient operation and management of water distribution networks (WDNs). However, it is often challenged by limited sensor observations. While graph neural networks (GNNs) have been used to improve hydraulic and water quality predictions of WDNs, their reliance on homogeneous graphs oversimplifies the diverse roles and interactions of hydraulic components, resulting in lower performance under dynamic system states. This research introduces a novel heterogeneous graph neural network (HGNN) framework, which models control units such as pumps and valves as distinct nodes while preserving their interactions through additional edge types. Experimental results using C-Town as a benchmark demonstrate that HGNN outperforms GNN in terms of accuracy, robustness, and adaptability, achieving a mean absolute percentage error (MAPE) of 1.88 % and a mean absolute error (MAE) of 1.70 m under a 95 % masking rate. Additionally, this study shows that optimal sensor placement reduces MAE by up to 15 %, and the proposed HGNN framework achieves high computational efficiency, highlighting its effectiveness in WDN analysis and management. This research offers an advanced and transferable approach for WDN pressure estimation, serving as a superior alternative to traditional pressure evaluation models
Mechanising Mediums: Spiritualism and Media Imaginaries in the Nineteenth and Twentieth Centuries
No full textThis paper engages with studies by media historians and media archaeologists of the significant role of the imagination in the development of communication technologies. It explores the trajectory of devices built by nineteenth and twentieth century spiritualists to facilitate direct communication with professed spirits of the dead, and whose design was attributed to inspiration from technically-minded denizens of the spirit world. Typically, these devices were built to limit or eliminate problems associated with spiritualist mediums, notably their possible fraudulence and the distorting effect of their minds on the quality of spirit communication. My analysis supports three arguments: first, that we need to take seriously both embodied and disembodied minds as the locations given by historical actors for imagined and realised communication technologies; second, the chequered histories of these devices highlight spiritualists’ doubts about the possibility and desirability of entirely replacing mediums by machines, and their faith in mediums’ ‘imaginations’ to act as superior ‘receivers’ of potentially problematic other-worldly intelligence; third, the devices offer new challenges to rigid distinctions between technological and religious experiences still adopted in the humanities