Open Research Exeter - University of Exeter
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Sources, Pathways and Sinks of Metal(loid) Contaminants in an Acid Mine Drainage-Affected River System
No full textAcid mine drainage (AMD) is a global environmental concern that persists long after mining activities cease and poses challenges for remediation efforts. Understanding the behaviour of AMD-related metal(loid) contaminants such as arsenic (As), copper (Cu) and zinc (Zn) in the aqueous and sediment phase is vital for protecting affected catchments, especially under differing hydrogeochemical conditions and their interaction with seawater upon entering coastal zones. This thesis aimed to investigate the sources, pathways, and sinks of contaminants within an AMD-affected river system (the Carnon River, UK). The mining history and short length (14 km) of the Carnon River catchment allowed an extensive investigation into the behaviour of the aqueous phase metal(loid)s from source (AMD) to sink (estuary).
Contaminant sources, loads, and transport mechanisms were assessed through a 12-month sampling of water and over 22 years of data from the UK Environment Agency. Sediment samples were also collected along the Carnon River and analysed for their spatial and particle size distribution of metal(loid)s and mineralogy.
Decadal (22 years) water quality monitoring revealed increasing As and iron (Fe) export to the coastal zone and ongoing AMD generation (and Cu and Zn release) at the County Adit (AMD input). The one-year (2021-2022) more detailed study recorded substantial load contributions of unfiltered and filtered Cu (59-81%), Zn (46-83%), and Fe (49-86%) from the County Adit to the cumulative load of the Carnon River. The main drivers of release were found in this study to be riverine discharge for Cu and Zn, while pH and Eh controlled As and Fe behaviour in the Carnon River.
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Aqueous- and sediment-phase As speciation analysis revealed a downstream shift, where aqueous As (III) became dominant and the proportion of As (V) decreased in the sediment phase. This process likely via reductive dissolution of Fe oxides and sequestration by sulfides in the estuary.
Maximum (filtered and unfiltered) contaminant loadings into the coastal zone were recorded at 742 kg/month (Cu), 3430 kg/month (Zn), 354 kg/month (As), 1960 kg/month (Fe) and 128,000 kg/month (sulfur, S). Sediment analysis revealed As, Cu and Zn concentrations were concentrated in both coarse (>2 mm) and fine (2 mm particles were likely detrital phases remobilised instream ore and mine waste. The <0.063 mm particles were most likely a mix of detrital and secondary Fe (oxy)hydroxides and other phases.
Overall, this study addresses knowledge gaps in AMD-affected river systems, informing future research and intervention strategies to address the environmental challenges posed by AMD contamination
An exploration of the factors influencing successful implementation, delivery and outcomes in an intensive care sedation study: process evaluation of the A2B RCT
No full textBackgroundChoice of sedation of critically ill patients is a core element of intensive care practice. The alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B) trial tested the effectiveness of two alpha agonist sedatives versus propofol in reducing time on mechanical ventilation in 38 intensive care units in the United Kingdom. To evaluate both how this complex trial was implemented and how this may have influenced trial outcomes, an understanding of the contextual and practice variation across multiple sites was required.Aim and objectivesThe aim of this process evaluation of the A2B trial was to determine how the intervention was delivered, the extent to which it was delivered as intended and the impact this had on outcomes. Specifically, we aimed to:Establish the degree to which the A2B intervention was delivered as intended, specifically in relation to fidelity, dose and reach across patients.Understand factors that impacted on successful delivery of both the A2B intervention and trial, in relation to attitudes and perceptions of staff, including context and standard care.Design and methodsA mixed-methods, multiphase design was used following extensive pre-trial exploration of current practice. Quantitative data were drawn from the main trial database covering 38 sites to assess the intervention’s fidelity, dose and reach in each site. Data were analysed descriptively and provided a low-moderate-high rating. Qualitative data were collected by interviews mid trial (phase 1) and end of trial (phase 2). Participants were recruited from a random sample of 30 intensive care units active at the time of sampling and included the principal investigator, research nurses and clinical staff. Semistructured interviews, informed by the trial’s logic model, lasted 45–60 minutes. Data collection focused on whether the intervention could be delivered as intended, factors that impacted upon successful delivery and understanding intervention adherence. Analysis used a framework approach based on the logic model. Data collection and qualitative analyses were completed prior to knowing the primary results of the trial.ResultsSite intervention adherence ratings for fidelity, dose and reach were low (4), moderate (20) and high (14). Participants from 12 intensive care units in each of phase 1 (33 staff) and phase 2 (36 staff) provided qualitative data; participating intensive care units differed between phases. Factors identified in phase 1 focused on intervention delivery and trial conduct and incorporated both organisational and participant-related factors. In phase 2, participant-related factors included clinician preference, individual equipoise, clinician resistance and staff capability and capacity, while A2B trial-related factors included concerns relating to safety and side effects, overnight deep sedation practice, patient comfort and trial documentation. Many of these factors were impacted by the COVID-19 pandemic, particularly in regard to staffing numbers and experience.LimitationsDue to the impact of the COVID-19 pandemic, most data collection occurred remotely through video-conferencing rather than planned at site observation and interviews.ConclusionOptimal sedation practice is influenced by multiple factors related to clinician perceptions, capacity and capability. Priorities in care focus on short-term safety and comfort. Limitations in staffing mean that longer-term consequences related to recovery and rehabilitation are second tier considerations.Future workFindings highlight the multiple contextual factors, including both organisational and participant-related characteristics, that should be considered when planning both clinical trials and changes to routine care. Multiple strategies for achieving behaviour change when implementing complex interventions are essential.</p
Beyond the “iconic” climate visual
No full textThis chapter focuses on the visual representation of climate change, taking a comparative approach to consider why "iconic" climate visuals and climate visual tropes tend to dominate news media coverage, often at the expense of a broader and more diverse representation of climate change. How climate change is reported is central in shaping how people think, feel, and act on climate change - with iconic images, such as a polar bear on melting ice, contributing toward an understanding of climate change as a remote issue. This chapter takes, as its point of departure, a critical focus on absent and marginalized images to explore how dominant media visualizations of climate change often sideline the perspectives of those most exposed to climate impacts; and how the news media fail to visualize how society might approach both climate mitigation and climate adaptation. The chapter begins by outlining a brief history of research into climate change and visual communication before focusing on three case studies of climate visuals: heatwaves, flooding, and media personalization. It concludes by providing recommendations for journalists, editors, and others involved in the visual journalism process and outlining fruitful areas for future research endeavors.</p
Replicating Semi-Implicit Semi-Lagrangian Stability in semi-implicit timestepping schemes using forward-in-time Eulerian advection
No full textSemi-implicit semi-Lagrangian schemes have excellent stability properties, making them popular for operational numerical weather prediction. That stability is obtained by integrating the equations along a Lagrangian trajectory. It might be desirable, for example as a route to achieving mass conservation, to avoid the integration along a Lagrangian trajectory and replace semi-Lagrangian advection with an explicit, forward-in-time Eulerian scheme. However, a naïve replacement of certain Lagrangian average quantities by Eulerian average quantities, including the advecting velocity, results in an unstable time integration scheme. Here, this instability is understood through a linear stability analysis of different time integration schemes for the rotating shallow-water equations. The analysis develops a general approach to restoring stability by a modified calculation of advection terms or advective fluxes in both the height and momentum equations, in which the advection operator acts on partially time-stepped or ‘predicted’ fields. The results of the analysis are supported by numerical experiments with the shallow-water equations.</p
A narrative inquiry exploring pupil, parent, and teacher perceptions of reintegration following suspension from primary school. How do Educational Psychologists (EPs) understand their role within this reintegration.
No full textRecent national data shows the highest levels of school exclusion ever recorded for primary and secondary aged students in the United Kingdom (UK), despite extensive literature detailing its overwhelmingly adverse impact for students, their families and their wider communities. The successful reintegration of a student back into school following suspension can reduce future exclusions and its associated adverse social, emotional and educational impacts. There is currently limited literature however, considering how students, parents and teachers perceive reintegration following suspension from primary school.
This study explored the narrative perceptions of students (n=2), their parent (n=2) and their teachers (n=3) regarding reintegration back into their primary school after suspension. What Educational Psychologists (EPs) perceived as their role within reintegration was then explored (n=9).
This study used a sequential, two-phase qualitative narrative inquiry design. Phase 1 comprised 6 individual narrative interviews within two participant triads consisting of a primary aged student their parent and class teacher. Data were restoried to create individual participant narratives and analysed to identify critical incidents, contradictions / dilemmas and themes. Phase 1 combined these individual narratives to create fictional narratives vignettes representing each participant role (student, parent, teacher). These were presented within phase 2.
Phase 1 findings identified participant conceptualisation of reintegration as one distinct element within broader exclusionary processes. This conceptualisation included the perceived importance in providing a ‘fresh start’ for the student, maintaining a productive home-school relationship and the challenges of acting within current educational systems and processes. Power dynamics and the impact of reintegration on individual role identities were also identified.
Phase 2 comprised two narrative focus groups with EPs employed within one rural, English, local authority (LA). The fictional narrative vignettes created in phase 1 were visually presented and discussions facilitated focused on perceptions of the EP role within reintegration contexts. Data were combined into a shared narrative through restorying before being analysed using narrative thematic analysis.
Phase 2 findings identified EPs felt appropriately skilled and well situated within educational systems to promote successful student reintegration following suspension. EPs identified their skills and knowledge in multi-systems thinking alongside interpersonal problem-solving skills as pivotal to promote and advocate for families and students within professional discussions, alongside enabling creative thinking and the personalisation of reintegration support. EPs identified tensions in their role from casework allocation models, between-school differences in resource and implementation approaches and professional expectations in assuming a ‘critical friend’ approach within schools.
This study provides insight into the perceptions of students, parents and teachers who experience reintegration, identifying areas of shared understanding alongside areas of difference in what is considered helpful or problematic. EPs perceive their role as potentially supportive to enable successful reintegration. Implications for EP practice and further areas of study are discussed.</p
A systematic review of the association between ultrasound-detected features and laboratory inflammatory biomarkers in hand osteoarthritis
No full textObjectivesTo systematically review observational studies for the relationship between ultrasound (US)-detected features and laboratory inflammatory biomarkers in hand osteoarthritis (OA).MethodsA systematic literature search was performed in MEDLINE, EMBASE, CINAHL, and Web of Science from their inception to June 2025 to identify relevant observational studies. Study quality was evaluated using the Newcastle–Ottawa Scale (NOS), with two independent reviewers validating the papers. Correlation coefficients and corresponding confidence intervals and P values between US-detected features and biomarkers were extracted and analysed.ResultsOut of 5,128 citations, four studies (546 participants, 91.75% female, mean age 56.1–66.3 years) scored >5 on the NOS. Significant correlations (r = 0.3–0.57) were found between serum inflammatory markers (e.g. TNF, MIP-β, PDGF-bb, IP-10) and grey-scale synovitis (GSS) specifically in erosive hand OA. No significant correlations were observed between other US-detected features (e.g. power Doppler (PD) signals, osteophytes (OST), effusion, cartilage thickness) and inflammatory biomarkers, with coefficients generally ConclusionThese findings highlight a critical gap in research linking US-detected features and serum inflammatory markers in hand OA. While some evidence suggests that US-detected GSS may reflect subclinical inflammation, particularly in erosive hand OA, inconsistent results across studies underscore the need for larger, standardised research to support phenotyping and inform targeted diagnostic and therapeutic strategies.</p
Exploring Problem-Based Learning in Teaching the Philosophy of Education to Trainee Teachers
No full textThis study focused on exploring problem-based learning in teaching the Philosophy of Education to trainee-teachers with reference to determining how trainee-teachers constructed Philosophy of Education schemas using the problem-based learning instructional design. To achieve this, problem-based learning was compared to the didactic/lectures in a quasi-experimental context that engaged 200 participants drawn from a Nigerian University using the random sampling technique. The study was situated within the social constructivist framework in a bid to conduct a deep exploration of the research aims and problems, and, in consequence, adopted the mixed methods quantitative, and qualitative, using five research instruments, namely: essay survey, achievement test, questionnaire, semi-structured interview, and observation. The essay survey was developed from the Philosophy of Education Module and contained 5 questions derived from 5 select topics and was administered simultaneously to the two groups that participated in the study in 3 phases and designated as tasks 1, 2, and 3 and were administered at the 1st, 6th, and the 12th weeks of the study. The achievement test adopted the multiple-choice format of 30 questions developed around the select topics and was administered simultaneously to both the problem-based learning and didactic/lecture groups after an intervention that lasted for 3 months. The problem-based learning group was taught using the problem-based learning technique using 5 case problems developed from the topics of metaphysics, pragmatism, existentialism, freedom, and realism while the comparing group undertook the conventional lectures using the same topics. A-50-item questionnaire was administered to 100 students of the problem-based learning group as they have had experience of didactic/lecture. 30 students of the problem-based learning group were randomly sampled and interviewed using questions of the open-ended format, whereupon, some live sessions of lessons were observed to determine how students engaged and interacted with their learning using the two instructional strategies. The instruments were validated, and reliability procedures were conducted. The questionnaire instrument, for instance, yielded a reliability value of 0.9 by Cronbach alpha. The achievement test was exposed to item analysis. Essay survey was validated by philosophy of education experts. The interview instrument was also validated using expert judgment. All instruments were pilot tested. Concept maps were adopted as data analysis strategy for the essays. Inferential statistics of the non-parametric type were utilized in the analysis of the achievement test scores. Based on Mann-Whitney U test, there was a significant difference in the achievements of the problem-based learning and the didactic/lecture groups (U=9462.5, p=.000). Principal axis factoring was adopted to reduce the 50-item questionnaire to smaller set of underlying factors with development of critical skills, promotion of team spirit, and development of professional skills emerging as factors using the scree plot approach while thematic analyses were used to analyze interview and observational data. Among other things the study found that problem-based learning occasioned greater conceptual changes among students with significant relationship between problem-based learning and students’ achievements recorded. Problem-based learning occasioned greater conceptual change and improved students’ achievements. It seems pedagogical framework for teaching philosophy of education should be developed based on the social constructivist criteria.</p
Optimal exercise modalities and doses for therapeutic management of osteoarthritis of the knee
No full textOsteoarthritis (OA) is a progressive osteoarticular disease affecting the whole joint. In the United Kingdom, OA is the most prevalent joint disease, with knee osteoarthritis (KOA) being the most common type of OA. Key symptoms of KOA include knee pain, stiffness, and loss of physical function. Different types of exercise can be performed in people with KOA, which exert different magnitudes of impact forces on the knee joint, whereby the National Institute for Health and Care Excellence (NICE) OA guidelines in fact recommend exercise as the core form of therapeutic OA management. However, the optimal type or dose – the cumulative intensity, duration, and frequency – of therapeutic exercise that most effectively provides KOA management is not currently known. This review aims to summarise and compare the literature, discussing optimal exercise modalities and doses for the management of KOA. All exercise modalities proved similarly beneficial at managing KOA with comparable improvements to knee pain, stiffness, and physical function, therefore with no optimal exercise modality identified. Benefits to KOA management was observed in everyone, including the elderly, obese, and those with severe KOA. Although, in those with severe KOA, walking was observed to only prevent further deterioration, rather than induce any symptomatic improvement. Furthermore, there was minimal difference between exercise modalities in relation to the improvements not only in KOA symptoms, but also modifiable KOA risk factors, adherence, adverse events, and QoL. Assessment of the dose-response relationship of each exercise modality showed that any dose of regular exercise was effective. Although, moderate intensity exercise performed three times weekly for 20-to-60-min appears optimal for KOA symptom control following most exercise modalities. Therefore, those with KOA should be encouraged to continue whatever exercise they currently do as should effectively manage symptoms, regardless of the modality or dose. However, those who do no exercise should use the present review in collaboration with clinicians via shared decision making to create a holistic exercise prescription. In summary, this review contributes to the literature through comprehensive discussion of different exercise modalities and doses in managing not only KOA symptoms, but modifiable KOA risk factors, exercise adherence, adverse events, and QoL. Additionally, summarised findings are discussed to give practical exercise recommendations to promote effective KOA management and recommendations for ongoing research
Transient structural features of Glycogen phosphorylase revealed by millisecond hydrogen deuterium exchange mass spectrometry
No full textAllostery is a fundamental mechanism of protein activation/inhibition, intricately linked to the structural dynamics of proteins upon stimulation by changes in their environment. Proteins have evolved to regulate their function by allostery from a variety of inputs, such as pH, metal-binding, ligand-binding, light and even the Earth’s weak magnetic field. However, a complete understanding of the exact mechanisms responsible for long-range intra-molecular signal transmission remains elusive, due to the limited availability of advanced biophysical techniques capable of capturing these signals across temporal and spatial dimensions. Glycogen phosphorylase (GlyP), the first allosteric enzyme described, demonstrates this challenge. The precise mechanisms controlling GlyP activity are unclear, particularly regarding the key regulatory loops of the active site 250′ (amino acid (248-260) and 280s (278-288), which are weakly stable and often lack density in structural models. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) is an extremely sensitive technique that quantifies backbone amide hydrogen-to-deuterium exchange, which is directly linked to local structural dynamics. Compared to structural elucidation methods, such as X-ray crystallography, HDX-MS offers higher sensitivity in detecting conformational bias, as low as a few percent difference and can probe structural dynamics with minimal sample requirements of pico-nanomole quantities. Protein amide HDX occurs with a vast dynamic range from µs up to at least days. It is this large dynamic range that presents the opportunity for information about the protein dynamics. Hence, HDX can bridge the gap between protein structure and biological function. Conventional HDX-MS sample preparation methods can reproducibly measure labelling times of >10s, leaving weakly stable intrinsically disordered regions (IDR)/proteins (IDP) intractable. Thus, development of reproducible and reliable millisecond HDX instruments is needed, as it can uncover the structural dynamics of IDP/IDR, crucial for protein function, as well as paving the way for potential non-equilibrium measurements of protein structural dynamics. The work in this thesis reports on the development of a novel millisecond HDX instrument and associated methods and softwares, revealing the allosteric mechanism of GlyP transition in greater detail. In Manuscript I, the construction, development and validation of an automated, rapid-mixing quench-flow HDX instrument is demonstrated. The broad applicability of this instrument is also shown by measuring rapid exchange kinetics of small peptides, furthermore, allowing for the analysis of an entire protein. In Manuscript II structural dynamic differences between the active and inactive form of GlyP were analysed. Structural motifs that critically regulate the activity of GlyP are weakly stable and therefore not often revealed by conventional HDX and often absent in X-ray crystallographic studies. In manuscript III, we were able to quantitatively measure the changes in local stability throughout GlyP, including these weakly stable sites. The key regulatory loops were probed by millisecond HDX and their site-localized stability differences quantified, supporting a longstanding hypothesis for the mechanism of allosteric regulation. In Manuscript IV a rapid, non-equilibrium millisecond HDX-MS method was demonstrated and used to precisely locate dynamic structural changes during glycogen phosphorylase's allosteric activation and inhibition. This approach revealed transient changes in localized structure, common to both allosteric activation by AMP and inhibition by caffeine. Altogether, the achievements in this work enhance our understanding of the complex mechanisms underpinning allostery. The mass spectrometry approach developed here allows for precise quantitative measurements and has the potential to be used in the future to observe dynamic changes in protein structure triggered by nearly any environmental stimulus
Bodies sensing air pollution in asthma research
No full textAir pollution knowledge practices are rapidly changing in science and policy research because of growing awareness of its harmful effects on environmental and human health. Informed by developments in environmental epigenetics and exposomics, a turn to the body is now evident, which includes generating more granular data to define individual disease risks and specify personal health interventions. By turning their attention towards the body, scientific researchers are also zeroing in on the contexts and conditions of exposure, and how living environments impact air’s toxicity. Evidence shows air pollution can contribute to the development of asthma. It is not just episodes of high levels of air pollution that matter but its sources, the timing of exposure, and accumulative effects. The knowledge practices of air pollution science are therefore useful sites for exploring how air pollution is entangled within the powerful systems and political economies that enact it. The recent monitoring of asthmatic bodies (rather than environments) with wearable sensors are informing knowledge about how and when exposure happens and is particularly harmful. Yet this more contextual, practical knowledge is often disregarded because the primary focus is on generating more data. By centring the ‘sensing body’ - which highlights the spaces, times and social practices of exposure that contribute to and worsen asthma - scientific studies can generate more critical analyses of air pollution that are relevant for guiding actions to prevent harm