Determination of degassing patterns in volcanic systems

The volume of gas contained within a silicic magma, dissolved and subsequently exsolved, greatly influences the behaviour of a volcano. There is a marked contrast between the behaviour of a volcano "open" to degassing, compared to one which is "closed". It is, therefore, essential to understand the entire degassing process of gas transport, storage and loss. The particular focus of this study is the effect different permeabilities and pressure gradients within a volcanic edifice have on the degree and pattern of the gas velocity. Gas loss is modelled numerically in two- and three-dimensions using a finite element approach. By combining the time-dependent continuity equation and Darcy's law, a partial differential equation is derived and solved for the pressure. The associated pressure gradient is used in Darcy's law to determine the corresponding gas velocity distribution. The momentum equation is also used to determine the surface displacement pattern resulting from the movement and storage of gas within the system. The model framework is applied to numerous volcanic scenarios including cracks and sealing within the dome structure and shear fractures at the margin between the conduit and country rock. Two case studies are investigated: Ash venting at Soufriere Hills volcano in March 2012, and persistent, repetitive ring-shaped degassing at Santiaguito. Quantitative estimates regarding gas emissions and deformation provide the link to constraining observations. The results show the country rock and dome are important and it is the relative permeabilities, rather than the actual values which determine the pressurisation. A decrease of just two orders of magnitude in the surrounding permeability could switch behaviour from effusive to explosive. For efficient gas storage within a volcano, a high permeability is required to hold the gas, whilst a low permeability is necessary to trap it. From the modelled surface displacement patterns and gas emissions at the surface, it may be possible to track the migration of large volumes of gas, particularly if used in conjunction with real-time monitoring of active volcanoes

CHARACTERISATION OF PHASE CURRENT IMBALANCE ON THREE-PHASE LV FEEDERS TO IDENTIFY OPPORTUNITIES FOR REBALANCING

ABSTRAC

Anthropause opportunities: Experimental perturbation of road traffic and the potential effects on wildlife

The SARS-CoV-2 pandemic severely reduced many human activities. So pronounced was the change, it has given rise to the term “anthropause”: the considerable alteration of modern human activities. Among these was surface transportation, with prolonged traffic reductions, in excess, of 50% in many countries. Roads and traffic are responsible for functionally fragmenting ecosystems, wildlife populations, and species interactions. The unintentional “dialing-down” of traffic has given continuous monitoring systems of wildlife-vehicle conflict a unique opportunity to study the consequences of perturbing this source of wildlife disturbance and mortality. Experimental manipulation of traffic at the global scale would not have been possible without mitigation responses to SARS-CoV-2. Such a perturbation allows robust empirical investigation into wildlife responses to traffic, including changes in mortality, behavior, genetic connectivity, and knock-on ecosystem effects, the responses to which can be replicated across a global network of wildlife-vehicle conflict monitoring systems. We review the extent to which these extensive data-collection systems provide the primary source of data to study many of these responses, providing the raw material to understand some striking wildlife consequences of the anthropause

Experiences of Establishing an Academic Early Phase Clinical Trials Unit

Background: Early phase trials are essential in drug development, determining appropriate dose levels and assessing preliminary activity. These trials are undertaken by industry and academia, with increasing collaborations between the two. There is pressure to perform these trials quickly, safely and robustly. However, there are inherent differences between developing and managing early phase, compared to late phase, drug trials. This paper describes an approach to establishing an academically-led early phase trial portfolio, highlighting lessons learned and sharing experiences. Methods: In 2009 the University of Leeds Clinical Trials Research Unit became the Clinical Trials Coordinating Office for Myeloma UK’s phase I and II trials. We embarked on a transition from working extensively in phase III to early phase trials development and conduct. This involved evaluating and revising our well-established standard operating procedures, visiting other academic early phase units, and developing essential new documentation and processes. Results: A core team of trial and data managers and statisticians was established to facilitate expertise and knowledge retention. A detailed training plan was implemented focusing on essential standard practices for early phase. These included pharmacovigilance, recruitment, trial design and set-up, data and site monitoring, and oversight committees. Training in statistical methods for early phase trials was incorporated. Conclusion: Initial scoping of early phase trial management and conduct was essential in establishing this early phase portfolio. Many of the processes developed were successful. However, regular review and evaluation were implemented to enable changes and ensure efficiencies. It is recommended that others embarking on this venture build on the experiences described in this article

The dynamic action of SecA during the initiation of protein translocation

Biotechnology and Biological Sciences Research Council (BBSRC) [a doctoral training grant Ph.D. studentship to S.W. and project grant number BB/I008675/1] and the Wellcome Trust [project grant number 084452]

Seeing the way: visual sociology and the distance runner's perspective

Employing visual and autoethnographic data from a two‐year research project on distance runners, this article seeks to examine the activity of seeing in relation to the activity of distance running. One of its methodological aims is to develop the linkage between visual and autoethnographic data in combining an observation‐based narrative and sociological analysis with photographs. This combination aims to convey to the reader not only some of the specific subcultural knowledge and particular ways of seeing, but also something of the runner's embodied feelings and experience of momentum en route. Via the combination of narrative and photographs we seek a more effective way of communicating just how distance runners see and experience their training terrain. The importance of subjecting mundane everyday practices to detailed sociological analysis has been highlighted by many sociologists, including those of an ethnomethodological perspective. Indeed, without the competence of social actors in accomplishing these mundane, routine understandings and practices, it is argued, there would in fact be no social order

Mobility of the SecA 2-helix-finger is not essential for polypeptide translocation via the SecYEG complex

The bacterial ATPase SecA and protein channel complex SecYEG form the core of an essential protein translocation machinery. The nature of the conformational changes induced by each stage of the hydrolytic cycle of ATP and how they are coupled to protein translocation are not well understood. The structure of the SecA–SecYEG complex revealed a 2-helix-finger (2HF) of SecA in an ideal position to contact the substrate protein and push it through the membrane. Surprisingly, immobilization of this finger at the edge of the protein channel had no effect on translocation, whereas its imposition inside the channel blocked transport. This analysis resolves the stoichiometry of the active complex, demonstrating that after the initiation process translocation requires only one copy each of SecA and SecYEG. The results also have important implications on the mechanism of energy transduction and the power stroke driving transport. Evidently, the 2HF is not a highly mobile transducing element of polypeptide translocation

Phosphorylation of toxoplasma gondii secreted proteins during acute and chronic stages of infection

ABSTRACT The intracellular parasite Toxoplasma gondii resides within a membrane-bound parasitophorous vacuole (PV) and secretes an array of proteins to establish this replicative niche. It has been shown previously that Toxoplasma secretes kinases and that numerous proteins are phosphorylated after secretion. Here, we assess the role of the phosphorylation of strand-forming protein 1 (SFP1) and the related protein GRA29, two secreted proteins with unknown function. We show that both proteins form stranded structures in the PV that are independent of the previously described intravacuolar network or actin. SFP1 and GRA29 can each form these structures independently of other Toxoplasma secreted proteins, although GRA29 appears to regulate SFP1 strands. We show that an unstructured region at the C termini of SFP1 and GRA29 is required for the formation of strands and that mimicking the phosphorylation of this domain of SFP1 negatively regulates strand development. When tachyzoites convert to chronic-stage bradyzoites, both proteins show a dispersed localization throughout the cyst matrix. Many secreted proteins are reported to dynamically redistribute as the cyst forms, and secreted kinases are known to play a role in cyst formation. Using quantitative phosphoproteome and proteome analyses comparing tachyzoite and early bradyzoite stages, we reveal widespread differential phosphorylation of secreted proteins. While we found no direct evidence for phosphorylation playing a dominant role for SFP1/GRA29 redistribution in the cyst, these data support a model in which secreted kinases and phosphatases contribute to the regulation of secreted proteins during stage conversion. IMPORTANCE Toxoplasma gondii is a common parasite that infects up to one-third of the human population. Initially, the parasite grows rapidly, infecting and destroying cells of the host, but subsequently switches to a slow-growing form and establishes chronic infection. In both stages, the parasite lives within a membrane-bound vacuole within the host cell, but in the chronic stage, a durable cyst wall is synthesized, which provides protection to the parasite during transmission to a new host. Toxoplasma secretes proteins into the vacuole to build its replicative niche, and previous studies identified many of these proteins as phosphorylated. We investigate two secreted proteins and show that a phosphorylated region plays an important role in their regulation in acute stages. We also observed widespread phosphorylation of secreted proteins when parasites convert from acute to chronic stages, providing new insight into how the cyst wall may be dynamically regulated

An adaptable implementation package targeting evidence-based indicators in primary care: a pragmatic cluster-randomised evaluation

Background In primary care, multiple priorities and system pressures make closing the gap between evidence and practice challenging. Most implementation studies focus on single conditions, limiting generalisability. We compared an adaptable implementation package against an implementation control and assessed effects on adherence to four different evidence-based quality indicators. Methods and findings We undertook two parallel, pragmatic cluster-randomised trials using balanced incomplete block designs in general practices in West Yorkshire, England. We used ‘opt-out’ recruitment, and we randomly assigned practices that did not opt out to an implementation package targeting either diabetes control or risky prescribing (Trial 1); or blood pressure (BP) control or anticoagulation in atrial fibrillation (AF) (Trial 2). Within trials, each arm acted as the implementation control comparison for the other targeted indicator. For example, practices assigned to the diabetes control package acted as the comparison for practices assigned to the risky prescribing package. The implementation package embedded behaviour change techniques within audit and feedback, educational outreach, and computerised support, with content tailored to each indicator. Respective patient-level primary endpoints at 11 months comprised the following: achievement of all recommended levels of haemoglobin A1c (HbA1c), BP, and cholesterol; risky prescribing levels; achievement of recommended BP; and anticoagulation prescribing. Between February and March 2015, we recruited 144 general practices collectively serving over 1 million patients. We stratified computer-generated randomisation by area, list size, and pre-intervention outcome achievement. In April 2015, we randomised 80 practices to Trial 1 (40 per arm) and 64 to Trial 2 (32 per arm). Practices and trial personnel were not blind to allocation. Two practices were lost to follow-up but provided some outcome data. We analysed the intention-to-treat (ITT) population, adjusted for potential confounders at patient level (sex, age) and practice level (list size, locality, pre-intervention achievement against primary outcomes, total quality scores, and levels of patient co-morbidity), and analysed cost-effectiveness. The implementation package reduced risky prescribing (odds ratio [OR] 0.82; 97.5% confidence interval [CI] 0.67–0.99, p = 0.017) with an incremental cost-effectiveness ratio of £1,359 per quality-adjusted life year (QALY), but there was insufficient evidence of effect on other primary endpoints (diabetes control OR 1.03, 97.5% CI 0.89–1.18, p = 0.693; BP control OR 1.05, 97.5% CI 0.96–1.16, p = 0.215; anticoagulation prescribing OR 0.90, 97.5% CI 0.75–1.09, p = 0.214). No statistically significant effects were observed in any secondary outcome except for reduced co-prescription of aspirin and clopidogrel without gastro-protection in patients aged 65 and over (adjusted OR 0.62; 97.5% CI 0.39–0.99; p = 0.021). Main study limitations concern our inability to make any inferences about the relative effects of individual intervention components, given the multifaceted nature of the implementation package, and that the composite endpoint for diabetes control may have been too challenging to achieve. Conclusions In this study, we observed that a multifaceted implementation package was clinically and cost-effective for targeting prescribing behaviours within the control of clinicians but not for more complex behaviours that also required patient engagement. Trial registration The study is registered with the ISRCTN registry (ISRCTN91989345)