Electromagnetic atmosphere-plasma coupling: the global atmospheric electric circuit

A description is given of the global atmospheric electric circuit operating between the Earth’s surface and the ionosphere. Attention is drawn to the huge range of horizontal and vertical spatial scales, ranging from 10−9 m to 1012 m, concerned with the many important processes at work. A similarly enormous range of time scales is involved from 10−6 s to 109 s, in the physical effects and different phenomena that need to be considered. The current flowing in the global circuit is generated by disturbed weather such as thunderstorms and electrified rain/shower clouds, mostly occurring over the Earth’s land surface. The profile of electrical conductivity up through the atmosphere, determined mainly by galactic cosmic ray ionization, is a crucial parameter of the circuit. Model simulation results on the variation of the ionospheric potential, ∼250 kV positive with respect to the Earth’s potential, following lightning discharges and sprites are summarized. Experimental results comparing global circuit variations with the neutron rate recorded at Climax, Colorado, are then discussed. Within the return (load) part of the circuit in the fair weather regions remote from the generators, charge layers exist on the upper and lower edges of extensive layer clouds; new experimental evidence for these charge layers is also reviewed. Finally, some directions for future research in the subject are suggested

A realistic evaluation : the case of protocol-based care

Background 'Protocol based care' was envisioned by policy makers as a mechanism for delivering on the service improvement agenda in England. Realistic evaluation is an increasingly popular approach, but few published examples exist, particularly in implementation research. To fill this gap, within this paper we describe the application of a realistic evaluation approach to the study of protocol-based care, whilst sharing findings of relevance about standardising care through the use of protocols, guidelines, and pathways. Methods Situated between positivism and relativism, realistic evaluation is concerned with the identification of underlying causal mechanisms, how they work, and under what conditions. Fundamentally it focuses attention on finding out what works, for whom, how, and in what circumstances. Results In this research, we were interested in understanding the relationships between the type and nature of particular approaches to protocol-based care (mechanisms), within different clinical settings (context), and what impacts this resulted in (outcomes). An evidence review using the principles of realist synthesis resulted in a number of propositions, i.e., context, mechanism, and outcome threads (CMOs). These propositions were then 'tested' through multiple case studies, using multiple methods including non-participant observation, interviews, and document analysis through an iterative analysis process. The initial propositions (conjectured CMOs) only partially corresponded to the findings that emerged during analysis. From the iterative analysis process of scrutinising mechanisms, context, and outcomes we were able to draw out some theoretically generalisable features about what works, for whom, how, and what circumstances in relation to the use of standardised care approaches (refined CMOs). Conclusions As one of the first studies to apply realistic evaluation in implementation research, it was a good fit, particularly given the growing emphasis on understanding how context influences evidence-based practice. The strengths and limitations of the approach are considered, including how to operationalise it and some of the challenges. This approach provided a useful interpretive framework with which to make sense of the multiple factors that were simultaneously at play and being observed through various data sources, and for developing explanatory theory about using standardised care approaches in practice

The off-prescription use of modafinil: an online survey of perceived risks and benefits

Cognitive enhancing drugs are claimed to improve cognitive functions such as learning and attention. However, little is known presently about the characteristics of off-prescription cognitive enhancing drug users or their perceived everyday experience with these drugs. As modafinil is the most commonly used off-prescription cognitive enhancing drug, the current study aimed to provide a detailed profile of modafinil users and their experiences and perceptions of this drug. To this end, an online survey, targeting cognitive enhancing drug users and students, was advertised on forum sites. Information was obtained regarding demographic data, illicit drug use, psychiatric diagnosis and experience of modafinil. Of the 404 respondents, 219 reported taking modafinil. Of these the majority were male, American or British, university educated and currently employed, with a mean age of 27. Overall, modafinil was perceived by users as being safe. Modafinil users reported higher levels of illicit drug use and psychiatric diagnosis than would be expected from population-based data. More frequent reported modafinil use was associated with higher numbers of perceived benefits whilst reported frequency of use was not associated with the number of perceived risks. There was also a tentative link between the reported use of modafinil and the reported presence of psychiatric disorders, largely depression and anxiety. Respondents who had reported a psychiatric diagnosis declared higher subjective benefits of modafinil. This may suggest further beneficial effects of modafinil or it may reflect insufficient medical treatment for psychiatric disorders in some people. Overall, the findings of the current study should be beneficial in informing clinicians and legislative bodies about the modafinil user profile and how modafinil is perceived

Perceived cognitive performance in off-prescription users of modafinil and methylphenidate: an online survey

Introduction Modafinil and methylphenidate are used off-prescription for cognitive enhancement in healthy individuals. Such use is often reported in online surveys, but it is unclear whether drug use for cognitive enhancement is motivated by perceived poor cognitive performance or a desire to improve good cognitive performance. The current study investigated whether off-prescription users of modafinil and methylphenidate differed in their self-perceived cognitive performance from people who do not take these drugs. Method An online survey targeting forum sites assessed self-perceived cognitive function via the Adult Attention Deficit/ Hyperactivity Disorder Self-Report Scale, the Cognitive Failures Questionnaire, and the General Procrastination Scale. Results There were 249 respondents, of whom 43% reported no use of modafinil and methylphenidate (the control group) and 58% reported use of one or both drugs without a prescription for cognitive enhancement. This created an independent samples design with three groups. On both the Adult Attention Deficit/ Hyperactivity Disorder Self-Report Scale and General Procrastination Scale, modafinil and methylphenidate users reported higher scores than the control group, indicating higher levels of perceived inattention and procrastination. Scores on the Cognitive Failures Questionnaire indicated that modafinil and methylphenidate users rated themselves as having fewer cognitive failures than controls. Conclusion These findings suggest that at least some reported off-prescription users of modafinil and methylphenidate may be seeking to reduce the impact of self-perceived poorer performance, particularly in forms of cognition that are likely to impact on self-directed or self-motivated work

A case study evaluation of implementation of a care pathway to support normal birth in one English birth centre: anticipated benefits and unintended consequences

Background: The policy drive for the UK National Health Service (NHS) has focused on the need for high quality services informed by evidence of best practice. The introduction of care pathways and protocols to standardise care and support implementation of evidence into practice has taken place across the NHS with limited evaluation of their impact. A multi-site case study evaluation was undertaken to assess the impact of use of care pathways and protocols on clinicians, service users and service delivery. One of the five sites was a midwifery-led Birth Centre, where an adapted version of the All Wales Clinical Pathway for Normal Birth had been implemented. Methods: The overarching framework was realistic evaluation. A case study design enabled the capture of data on use of the pathway in the clinical setting, use of multiple methods of data collection and opportunity to study and understand the experiences of clinicians and service users whose care was informed by the pathway. Women attending the Birth Centre were recruited at their 36 week antenatal visit. Episodes of care during labour were observed, following which the woman and the midwife who cared for her were interviewed about use of the pathway. Interviews were also held with other key stakeholders from the study site. Qualitative data were content analysed. Results: Observations were undertaken of four women during labour. Eighteen interviews were conducted with clinicians and women, including the women whose care was observed and the midwives who cared for them, senior midwifery managers and obstetricians. The implementation of the pathway resulted in a number of anticipated benefits, including increased midwifery confidence in skills to support normal birth and promotion of team working. There were also unintended consequences, including concerns about a lack of documentation of labour care and negative impact on working relationships with obstetric and other midwifery colleagues. Women were unaware their care was informed by a care pathway. Conclusion: Care pathways are complex interventions which generate a number of consequences for practice. Those considering introduction of pathways need to ensure all relevant stakeholders are engaged with this and develop robust evaluation strategies to accompany implementation

Brief communication: Earthquake–cloud coupling through the global atmospheric electric circuit

We illustrate how coupling could occur between surface air and clouds via the global electric circuit – through Atmospheric Lithosphere–Ionosphere Charge Exchange (ALICE) processes – in an attempt to develop a physical understanding of the possible relationships between earthquakes and cloud

Implementation, impact and costs of policies for safe staffing in acute NHS trusts

The aim of this research has been to describe the implementation of safe staffing policies in NHS general acute Trusts in England looking at costs and consequences, and examining the factors that have influenced implementation. A mix of qualitative and quantitative methods were used (national survey, analysis of national data, four case studies, realist evaluation) to examine the impact of policies nationally, and explore commonality and variation in local responses to safe staffing policies. The report is based on independent research commissioned and funded by the NIHR Policy Research Programme (“Implementation, Impact and Costs of Policies for Safe Staffing in Acute NHS Trusts”, PR-ST-1115-10017). The views expressed are those of the authors and not necessarily those of the NIHR, the Department of Health and Social Care, ‘arm’s length bodies’ or other government departments

Velocity profile of granular flows inside silos and hoppers

We measure the flow of granular materials inside a quasi-two dimensional silo as it drains and compare the data with some existing models. The particles inside the silo are imaged and tracked with unprecedented resolution in both space and time to obtain their velocity and diffusion properties. The data obtained by varying the orifice width and the hopper angle allows us to thoroughly test models of gravity driven flows inside these geometries. All of our measured velocity profiles are smooth and free of the shock-like discontinuities ("rupture zones") predicted by critical state soil mechanics. On the other hand, we find that the simple Kinematic Model accurately captures the mean velocity profile near the orifice, although it fails to describe the rapid transition to plug flow far away from the orifice. The measured diffusion length $b$, the only free parameter in the model, is not constant as usually assumed, but increases with both the height above the orifice and the angle of the hopper. We discuss improvements to the model to account for the differences. From our data, we also directly measure the diffusion of the particles and find it to be significantly less than predicted by the Void Model, which provides the classical microscopic derivation of the Kinematic Model in terms of diffusing voids in the packing. However, the experimental data is consistent with the recently proposed Spot Model, based on a simple mechanism for cooperative diffusion. Finally, we discuss the flow rate as a function of the orifice width and hopper angles. We find that the flow rate scales with the orifice size to the power of 1.5, consistent with dimensional analysis. Interestingly, the flow rate increases when the funnel angle is increased.Comment: 17 pages, 8 figure

Recent advances in global electric circuit coupling between the space environment and the troposphere

The global atmospheric electric circuit is driven by thunderstorms and electrified rain/shower clouds and is also influenced by energetic charged particles from space. The global circuit maintains the ionosphere as an equipotential at∼+250 kV with respect to the good conducting Earth (both land and oceans). Its “load” is the fair weather atmosphere and semi-fair weather atmosphere at large distances from the disturbed weather “generator” regions. The main solar-terrestrial (or space weather) influence on the global circuit arises from spatially and temporally varying fluxes of galactic cosmic rays (GCRs) and energetic electrons precipitating from the magnetosphere. All components of the circuit exhibit much variability in both space and time. Global circuit variations between solar maximum and solar minimum are considered together with Forbush decrease and solar flare effects. The variability in ion concentration and vertical current flow are considered in terms of radiative effects in the troposphere, through infra-red absorption, and cloud effects, in particular possible cloud microphysical effects from charging at layer cloud edges. The paper identifies future research areas in relation to Task Group 4 of the Climate and Weather of the Sun-Earth System (CAWSES-II) programme

A pragmatic cluster randomised trial evaluating three implementation interventions

Background Implementation research is concerned with bridging the gap between evidence and practice through the study of methods to promote the uptake of research into routine practice. Good quality evidence has been summarised into guideline recommendations to show that peri-operative fasting times could be considerably shorter than patients currently experience. The objective of this trial was to evaluate the effectiveness of three strategies for the implementation of recommendations about peri-operative fasting. Methods A pragmatic cluster randomised trial underpinned by the PARIHS framework was conducted during 2006 to 2009 with a national sample of UK hospitals using time series with mixed methods process evaluation and cost analysis. Hospitals were randomised to one of three interventions: standard dissemination (SD) of a guideline package, SD plus a web-based resource championed by an opinion leader, and SD plus plan-do-study-act (PDSA). The primary outcome was duration of fluid fast prior to induction of anaesthesia. Secondary outcomes included duration of food fast, patients' experiences, and stakeholders' experiences of implementation, including influences. ANOVA was used to test differences over time and interventions. Results Nineteen acute NHS hospitals participated. Across timepoints, 3,505 duration of fasting observations were recorded. No significant effect of the interventions was observed for either fluid or food fasting times. The effect size was 0.33 for the web-based intervention compared to SD alone for the change in fluid fasting and was 0.12 for PDSA compared to SD alone. The process evaluation showed different types of impact, including changes to practices, policies, and attitudes. A rich picture of the implementation challenges emerged, including inter-professional tensions and a lack of clarity for decision-making authority and responsibility. Conclusions This was a large, complex study and one of the first national randomised controlled trials conducted within acute care in implementation research. The evidence base for fasting practice was accepted by those participating in this study and the messages from it simple; however, implementation and practical challenges influenced the interventions' impact. A set of conditions for implementation emerges from the findings of this study, which are presented as theoretically transferable propositions that have international relevance. Trial registration ISRCTN18046709 - Peri-operative Implementation Study Evaluation (POISE