Critical Eruptive Controls of an Intra-plate Volcano: Ascension Island, South Atlantic

Understanding what drives transitions in eruptive style is an important challenge in volcanology. Existing descriptions of small-volume trachytic eruptions often record transitions in eruptive behaviour, including and outwith explosive-effusive transitions, but detailed ascent and eruption dynamics reconstructions are rare. Historically, poor deposit preservation and exposure and unconstrained trachytic melt physical properties have contributed to a dearth of relevant literature. Here, I first make use of recent advances in understanding trachytic melt properties to reconstruct ascent and eruption dynamics of a particularly well-preserved and -exposed small-volume eruption on Ascension Island, South Atlantic - the Echo Canyon eruption (EC). Forensic stratigraphy, petrographic analysis, reconstruction of bulk magma properties and quantitative textural analysis reveal: the EC eruption underwent several transitions in eruptive behaviour, driven by rapid ascent, decompression and vesiculation. Further, peak explosion intensity equivalent to volcanic explosivity index (VEI) 6 eruptions was transiently achieved before transition to effusive activity by rapid evolution of permeable vesicle networks in conduit margin shear zones. Next, I use 2D and 3D textural analyses of a stratigraphically and compositionally well-constrained basalt-rhyolite ‘Mingled Fall’ deposit to assess how mingling impacts vesiculation during ascent. I find vesiculation in mingled clasts’ basaltic and rhyolitic regions progressed independently with little–no shear. In the basaltic regions, connectivity development was only slightly inhibited relative to scoriaceous clasts. I show 2D and 3D studies in texturally complex samples return different vesiculation histories. The 3D vesicle size distribution studies are more reliable for complex clasts, whereas 2D shape descriptors are better constrained and more useful for inter-eruption comparisons. Finally, I demonstrate how frameworks developed throughout offer insights into the evolution of the volumetrically comparable La Soufrière St Vincent, 2020-21 eruption. This thesis makes a useful contribution to understanding ascent and eruption dynamics of small-volume, but potentially high-impact events, common to isolated ocean island settings

Challenges of recruiting emergency department patients to a qualitative study: a thematic analysis of researchers’ experiences

Background: At times of increasing pressure on emergency departments, and the need for research into different models of service delivery, little is known about how to recruit patients for qualitative research in emergency departments. We report from one study which aimed to collect evidence on patients’ experiences of attending emergency departments with different models of using general practitioners, but faced challenges in recruiting patients. This paper aims to identify and reflect on the challenges faced at all stages of patient recruitment, from identifying and inviting eligible patients, consenting them for participation and finally to engaging them in interviews, and make recommendations based on our learning.Methods: A thematic analysis was carried out on field-notes taken during research visits and meeting minutes of discussions to review and improve patient recruitment throughout the study.Results: The following factors influenced the success of patient recruitment in the emergency department setting:complicated or time-consuming electronic health record systems for identifying patients; narrow participant eligibility criteria; limited research nurse support; and lack of face-to-face communication between researchers and eligible patients.Conclusions: This paper adds to the methodological evidence for improving patient recruitment in different settings, with a focus on qualitative research in emergency departments. Our findings have implications for future studies attempting to recruit patients in similar settings

Patients’ experiences of attending emergency departments where primary care services are located: qualitative findings from patient and clinician interviews from a realist evaluation

Background: Patient experience is an important outcome and indicator of healthcare quality, and patient reported experiences are key to improving quality of care. While patient experience in emergency departments (EDs) has been reported in research, there is limited evidence about patients’ specific experiences with primary care services located in or alongside EDs. We aim to identify theories about patient experience and acceptability of being streamed to a primary care clinician in an ED. Methods: Using theories from a rapid realist review as a basis, we interviewed 24 patients and 106 staff members to generate updated theories about patient experience and acceptability of streaming to primary care services in EDs. Feedback from 56 stakeholders, including clinicians, policymakers and patient and public members, as well as observations at 13 EDs, also contributed to the development of these theories, which we present as a programme theory. Results: We found that patients had no expectations or preferences for which type of clinician they were seen by, and generally found being streamed to a primary care clinician in the ED acceptable. Clinicians and patients reported that patients generally found primary care streaming acceptable if they felt their complaint was dealt with suitably, in a timely manner, and when clinicians clearly communicated the need for investigations, and how these contributed to decision-making and treatment plans. Conclusions: From our findings, we have developed a programme theory to demonstrate that service providers can expect that patients will be generally satisfied with their experience of being streamed to, and seen by, primary care clinicians working in these services. Service providers should consider the potential advantages and disadvantages of implementing primary care services at their ED. If primary care services are implemented, clear communication is needed between staff and patients, and patient feedback should be sought

Identifying safe care processes when GPs work in or alongside emergency departments: realist evaluation

Background: Increasing pressure on emergency services has led to the development of different models of care delivery including GPs working in or alongside emergency departments (EDs), but with a lack of evidence for patient safety outcomes. Aim: We aimed to explore how care processes work and how patient safety incidents associated with GPs working in ED settings may be mitigated. Design and Setting: We used realist methodology with a purposive sample of 13 EDs with different GP service models. We sought to understand the relationship between contexts, mechanisms and outcomes to develop theories about how and why patient safety incidents may occur, and how safe care was perceived to be delivered. Method: We collected qualitative data (observations, semi-structured audio-recorded staff interviews and local patient safety incident reports). We coded data using ‘if, then, because’ statements to refine initial theories developed from an earlier rapid realist literature review and analysis of a sample of national patient safety incident reports. Results: We developed a programme theory to describe how safe patient care was perceived to be delivered in these service models including: an experienced streaming nurse using local guidance and early warning scores; support for GPs’ clinical decision-making with clear governance processes relevant to the intended role (traditional GP approach or emergency medicine approach); and strong clinical leadership to promote teamwork and improve communication between services. Conclusion: Our findings can be used as a focus for more in-depth human factors investigations to optimise work conditions in this complex care delivery settin

Zircon double-dating, trace element and O isotope analysis to decipher late Pleistocene explosive-effusive eruptions from a zoned ocean-island magma system, Ascension Island

In this first detailed study of zircon from Ascension Island, South Atlantic, we take a novel approach combining trace element and O isotope compositional data with double-dating (disequilibrium 238U–230Th and (U–Th)/He) to decipher timescales and dynamics of magmatic processes. The Echo Canyon (EC) sequence comprises small-volume explosive-effusive eruptions of trachyte that tapped a compositionally zoned magma system. Associated volcanic hazards may be constrained from the age of volcanism, duration of magma storage, and magma source and plumbing system character. Zircon U–Th–Pb dating of lithic lava clasts has revealed recurrent evolved volcanism at 1.34 and 0.6 Ma, and 95 ka. The (U–Th)/He zircon cooling ages indicate that most of the EC explosive-effusive sequence erupted in a brief episode at ca. 95 ka. Additionally, uniform 238U–230Th zircon crystallisation ages suggest moderately protracted magma storage with melt present at depth for at most 103–104 years before eruption. The enriched character of zircon trace element compositions, relative to MORB, in the absence of a continental crustal signature in the oxygen isotope values (δ18O range 2.67–5.63‰), suggests the presence of an enriched component in the EC magma source. Furthermore, low δ18O zircon compositions imply assimilation of high temperature hydrothermally altered country rock by the source magma. The mineral assemblage in crystal-poor pumices indicates equilibrium storage conditions: zircon saturation and Ti-in-zircon crystallisation temperatures are consistent with alkali feldspar-melt temperatures. Significantly, zircon crystals were preserved both as macrocryst inclusions and in the groundmass of EC explosive and effusive deposits. These rocks preserve evidence of magma evolution by fractional crystallisation. This process led to pre-eruptive compositional stratification, which is evidenced in the range of whole-rock major and trace element compositions and zircon Zr/Hf values. Notably, zircon crystallisation and cooling ages derived from pumice, lava, and accidental lithic lava clasts in highly explosive pyroclastic deposits, have revealed episodes of evolved magmatism that would otherwise have gone undetected. In addition, the zircon trace element and isotope compositions, in combination with the range of crystallisation ages, evidence progressively deeper tapping of less evolved magma stored in discrete lenses. Thus, a combined zircon geochronological-geochemical approach can place constraints on the ca. 0.6 Ma recurrence of past explosive-effusive pulses of millennial to decamillennial duration and their enriched magma sources. This information is relevant for assessing hazards and informing monitoring and forecasting efforts to assist in managing associated risks for small ocean island volcanoes with particularly vulnerable populations and infrastructure

Implementing public involvement throughout the research process—Experience and learning from the GPs in EDs study

Background: Public involvement in health services research is encouraged. Descriptions of public involvement across the whole research cycle of a major study are uncommon and its effects on research conduct are poorly understood. Aim: This study aimed to describe how we implemented public involvement, reflect on process and effects in a large‐scale multi‐site research study and present learning for future involvement practice. Method: We recorded public involvement roles and activities throughout the study and compared these to our original public involvement plan included in our project proposal. We held a group interview with study co‐applicants to explore their experiences, transcribed the recorded discussion and conducted thematic analysis. We synthesized the findings to develop recommendations for future practice. Results: Public contributors' activities went beyond strategic study planning and management to include active involvement in data collection, analysis and dissemination. They attended management, scrutiny, planning and task meetings. They also facilitated public involvement through annual planning and review sessions, conducted a Public Involvement audit and coordinated public and patient input to stakeholder discussions at key study stages. Group interview respondents said that involvement exceeded their expectations. They identified effects such as changes to patient recruitment, terminology clarification and extra dissemination activities. They identified factors enabling effective involvement including team and leader commitment, named support contact, building relationships and demonstrating equality and public contributors being confident to challenge and flexible to meet researchers' timescales and work patterns. There were challenges matching resources to roles and questions about the risk of over‐professionalizing public contributors. Conclusion: We extended our planned approach to public involvement and identified benefits to the research process that were both specific and general. We identified good practice to support effective public involvement in health services research that study teams should consider in planning and undertaking research. Public Contribution: This paper was co‐conceived, co‐planned and co‐authored by public contributors to contribute research evidence, based on their experiences of active involvement in the design, implementation and dissemination of a major health services research study

Emergency department clinical leads’ experiences of implementing primary care services where GPs work in or alongside emergency departments in the UK: a qualitative study

Background To manage increasing demand for emergency and unscheduled care NHS England policy has promoted services in which patients presenting to Emergency Departments (EDs) with non-urgent problems are directed to general practitioners (GPs) and other primary care clinicians working within or alongside emergency departments. However, the ways that hospitals have implemented primary care services in EDs are varied. The aim of this study was to describe ED clinical leads’ experiences of implementing and delivering ‘primary care services’ and ‘emergency medicine services’ where GPs were integrated into the ED team. Methods We conducted interviews with ED clinical leads in England (n = 19) and Wales (n = 2). We used framework analysis to analyse interview transcripts and explore differences across ‘primary care services’, ‘emergency medicine services’ and emergency departments without primary care services. Results In EDs with separate primary care services, success was reported when having a distinct workforce of primary care clinicians, who improved waiting times and flow by seeing primary care-type patients in a timely way, using fewer investigations, and enabling ED doctors to focus on more acutely unwell patients. Some challenges were: trying to align their service with the policy guidance, inconsistent demand for primary care, accessible community primary care services, difficulties in recruiting GPs, lack of funding, difficulties in agreeing governance protocols and establishing effective streaming pathways. Where GPs were integrated into an ED workforce success was reported as managing the demand for both emergency and primary care and reducing admissions. Conclusions Introducing a policy advocating a preferred model of service to address primary care demand was not useful for all emergency departments. To support successful and sustainable primary care services in or alongside EDs, policy makers and commissioners should consider varied ways that GPs can be employed to manage variation in local demand and also local contextual factors such as the ability to recruit and retain GPs, sustainable funding, clear governance frameworks, training, support and guidance for all staff. Whether or not streaming to a separate primary care service is useful also depended on the level of primary care demand

Improving access for community health and sub-acute outpatient services: protocol for a stepped wedge cluster randomised controlled trial

BACKGROUND: Waiting lists for treatment are common in outpatient and community services, Existing methods for managing access and triage to these services can lead to inequities in service delivery, inefficiencies and divert resources from frontline care. Evidence from two controlled studies indicates that an alternative to the traditional &quot;waitlist and triage&quot; model known as STAT (Specific Timely Appointments for Triage) may be successful in reducing waiting times without adversely affecting other aspects of patient care. This trial aims to test whether the model is cost effective in reducing waiting time across multiple services, and to measure the impact on service provision, health-related quality of life and patient satisfaction. METHODS/DESIGN: A stepped wedge cluster randomised controlled trial has been designed to evaluate the impact of the STAT model in 8 community health and outpatient services. The primary outcome will be waiting time from referral to first appointment. Secondary outcomes will be nature and quantity of service received (collected from all patients attending the service during the study period and health-related quality of life (AQOL-8D), patient satisfaction, health care utilisation and cost data (collected from a subgroup of patients at initial assessment and after 12&nbsp;weeks). Data will be analysed with a multiple multi-level random-effects regression model that allows for cluster effects. An economic evaluation will be undertaken alongside the clinical trial. DISCUSSION: This paper outlines the study protocol for a fully powered prospective stepped wedge cluster randomised controlled trial (SWCRCT) to establish whether the STAT model of access and triage can reduce waiting times applied across multiple settings, without increasing health service costs or adversely impacting on other aspects of patient care. If successful, it will provide evidence for the effectiveness of a practical model of access that can substantially reduce waiting time for outpatient and community services with subsequent benefits for both efficiency of health systems and patient care.<br /