Magma storage and differentiation in volcanic arcs: examples from the central Aeolian arc, Italy

The Aeolian arc is characterised by its complex geodynamic setting, with a heterogeneous mantle source and differing extents of shallow-level magmatic processes. These processes result in large within arc geochemical variations influencing the magma compositions erupted and styles of volcanism in the region distinguishing it from other volcanic arcs worldwide. Intermediate to silicic volcanism dominates during the most recent eruption stages in the central Aeolian arc, on Vulcano, Lipari and Salina after the first occurrence of rhyolitic volcanism in the Aeolian archipelago. Key eruptive centres from the central Aeolian arc characterised by alternating periods of Vulcanian to Subplinian explosive events and lava flow effusion were selected as case studies including La Fossa di Vulcano and the Lentia domes on Vulcano, the southern dome field and northern rhyolitic centres on Lipari and the Pollara crater on Salina. This study quantitatively assesses the role of crustal contamination in the generation of intermediate and silicic magmas in the central Aeolian arc, geochemically and isotopically constrains the evolution of the La Fossa di Vulcano magmatic system and identifies the shallow conduit processes during the 1888-90 eruption of La Fossa di Vulcano. We present a stratigraphically controlled dataset to elucidate magma storage conditions, magmatic processes occurring at different levels in the subvolcanic system, and the role and extent of crustal assimilation in producing intermediate to felsic magmas since the switch to dominantly rhyolitic volcanism in the central Aeolian arc. New major- and trace-element geochemistry, stable- and radiogenic isotope geochemistry data from characteristic crustal xenoliths from the different levels within the Calabro Peloritano basement are presented to quantify the role of crustal contamination during magmatic evolution in the central Aeolian arc. This study of the central Aeolian arc quantitatively assesses the role of source and crustal contamination at arguably the most hazardous volcanoes in Aeolian arc

Implementation of U.K. Earth system models for CMIP6

We describe the scientific and technical implementation of two models for a core set of experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The models used are the physical atmosphere-land-ocean-sea ice model HadGEM3-GC3.1 and the Earth system model UKESM1 which adds a carbon-nitrogen cycle and atmospheric chemistry to HadGEM3-GC3.1. The model results are constrained by the external boundary conditions (forcing data) and initial conditions.We outline the scientific rationale and assumptions made in specifying these. Notable details of the implementation include an ozone redistribution scheme for prescribed ozone simulations (HadGEM3-GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in the simulation of background natural vegetation.We discuss the implications of these decisions for interpretation of the simulation results. These simulations are expensive in terms of human and CPU resources and will underpin many further experiments; we describe some of the technical steps taken to ensure their scientific robustness and reproducibility

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention

Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

BACKGROUND: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. METHODS: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). FINDINGS: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29-146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0- 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25-1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39-1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65-1·60]; p=0·92). INTERPRETATION: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention. FUNDING: British Heart Foundation

Investigating speech motor control using vocal tract imaging, fMRI, and brain stimulation

The aim of this thesis was to understand speech motor control in both people who are typically fluent (PWTF) and people who stutter (PWS). To do this, I used a multi-modal approach including vocal tract MRI, functional MRI during task and brain stimulation. These methods allowed me to explore speech motor control from the brain’s control of speech to the movement of the articulators. First, I conducted a systematic review of previous studies of articulation in PWS that used a variety of different methods. Technological advances over the last 15 years have offered new insight into the speech motor control of PWS by measuring precise movements of the articulators involved in speech. I then used vocal tract MRI (vtMRI) to look at the speech movements in PWS. As this is a novel technique, experiments have been designed to first replicate and then extend key results identified via the systematic review that used alternative methods. We found that PWS, on average, produced more variable movements than typically fluent speakers even during fluent productions of simple nonwords. This indicates general, trait-level differences in the control of the articulators between PWS and people who are typically fluent. I used functional MRI of the brain to investigate differences in the neural control of speech in PWS and PWTF. I used a task known as the Stop-Signal task that was previously used to investigate inhibitory motor control in both speech and manual movements (Xue, Aron & Poldrack, 2008). The results support the role of an over-active inhibitory response in PWS compared with controls. Finally, I designed a study to investigate whether transcranial direct current stimulation (tDCS) can modulate speech articulation in a typically fluent population. I used both behavioural and electrophysiological outcomes to assess the role of tDCS in modulating performance on a complex articulation task. TDCS did not modulate performance on a complex articulation task in healthy young adults. TDCS applied concurrently with task learning also failed to modulate cortical excitability in expected ways

A feminist materialist inspired analysis of the meaning and management of pregnancy and reproductive health in Olympic and Paralympic female athletes

The number of elite female athletes returning to professional sport following childbirth has gradually increased in recent years. There now exists a burgeoning of scholarship across sport and health-related disciplines that have paid attention to the experiences of pregnancy and motherhood in elite female athlete populations. This paper contributes to this expanding topic of inquiry by taking inspiration from feminist materialist approaches to examine the experiences and politics of pregnancy and reproductive health in elite female Olympic and Paralympic athletes on the United Kingdom elite sport funded programme–The World Class Programme (WCP). In doing so, we begin to foreground the bio-social-material practices and entanglements that constitute the WCP environment which actively shape athletes’ understandings of reproductive health and choice around pregnancy in particular ways. We discuss how the presented data has implications for female athlete embodied subjectivity and reproductive realities that complicate cultural narratives around athlete agency and gender equities in elite sport