336 research outputs found
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Horizontal and vertical structure of the Eyjafjallajökull ash cloud over the UK: a comparison of airborne lidar observations and simulations
During April and May 2010 the ash cloud from the eruption of the Icelandic volcano Eyjafjallajökull caused widespread disruption to aviation over northern Europe. The location and impact of the eruption led to a wealth of observations of the ash cloud were being obtained which can be used to assess modelling of the long range transport of ash in the troposphere. The UK FAAM (Facility for Airborne Atmospheric Measurements) BAe-146-301 research aircraft overflew the ash cloud on a number of days during May. The aircraft carries a downward looking lidar which detected the ash layer through the backscatter of the laser light. In this study ash concentrations derived from the lidar are compared with simulations of the ash cloud made with NAME (Numerical Atmospheric-dispersion Modelling Environment), a general purpose atmospheric transport and dispersion model.
The simulated ash clouds are compared to the lidar data to determine how well NAME simulates the horizontal and vertical structure of the ash clouds. Comparison between the ash concentrations derived from the lidar and those from NAME is used to define the fraction of ash emitted in the eruption that is transported over long distances compared to the total emission of tephra. In making these comparisons possible position errors in the simulated ash clouds are identified and accounted for.
The ash layers seen by the lidar considered in this study were thin, with typical depths of 550–750 m. The vertical structure of the ash cloud simulated by NAME was generally consistent with the observed ash layers, although the layers in the simulated ash clouds that are identified with observed ash layers are about twice the depth of the observed layers. The structure of the simulated ash clouds were sensitive to the profile of ash emissions that was assumed. In terms of horizontal and vertical structure the best results were obtained by assuming that the emission occurred at the top of the eruption plume, consistent with the observed structure of eruption plumes. However, early in the period when the intensity of the eruption was low, assuming that the emission of ash was uniform with height gives better guidance on the horizontal and vertical structure of the ash cloud.
Comparison of the lidar concentrations with those from NAME show that 2–5% of the total mass erupted by the volcano remained in the ash cloud over the United Kingdom
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Using data insertion with the NAME model to simulate the 8 May 2010 Eyjafjallajökull volcanic ash cloud
A data insertion method, where a dispersion model is initialized from ash properties derived from a series of satellite observations, is used to model the 8 May 2010 Eyjafjallajökull volcanic ash cloud which extended from Iceland to northern Spain. We also briefly discuss the application of this method to the April 2010 phase of the Eyjafjallajökull eruption and the May 2011 Grímsvötn eruption. An advantage of this method is that very little knowledge about the eruption itself is required because some of the usual eruption source parameters are not used. The method may therefore be useful for remote volcanoes where good satellite observations of the erupted material are available, but little is known about the properties of the actual eruption. It does, however, have a number of limitations related to the quality and availability of the observations. We demonstrate that, using certain configurations, the data insertion method is able to capture the structure of a thin filament of ash extending over northern Spain that is not fully captured by other modeling methods. It also verifies well against the satellite observations according to the quantitative
object-based quality metric, SAL—structure, amplitude, location, and the spatial coverage metric, Figure of
Merit in Space
Fibre-based ratiometric fluorescence imaging for contrast enhancement of spectrally similar signals in the lung
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Analysis of three epoetin alpha products by LC and LC-MS indicates differences in glycosylation critical quality attributes, including sialic acid content
Erythropoietin (EPO) is one of the main therapeutics used to treat anaemic patients, greatly improving their quality of life. In this study, biosimilars Binocrit and a development product, called here CIGB-EPO, were compared to the originator product, Eprex. All three are epoetin alpha products, reputed to have similar glycosylation profiles. The quality, safety and efficacy of this biotherapeutic depend on the following glycosylation critical quality attributes (GCQAs): sialylation, N-glycolyl-neuraminic acid (Neu5Gc) content, branching, N-acetyl-lactosamine (LacNAc) extensions and O-acetylation pattern. Reverse-phase ultra high pressure liquid chromatography (RP-UHPLC) analysis of acid-released, 1,2-diamino-4,5-methylenedioxybenzene (DMB) labelled sialic acid derivatives and hydrophilic interaction liquid chromatography (HILIC) in combination with mass spectrometry (HILIC-UHPLC-MS) of procainamide (PROC) labelled N-glycans were the analytical tools used. An automated method for enzymatic release and PROC labelling was applied for the first time to the erythropoiesis stimulating agent (ESA) products, which facilitated novel, in-depth characterisation, and allowed identification of precise structural features including the location of O-acetyl groups on sialic acid (SA) moie-ties. Samples were digested by a sialate-O-acetylesterase (NanS) to confirm the presence of O-acetyl groups. It was found that Eprex contained the greatest relative abundance of O-acetylated derivatives, Binocrit expressed the least Neu5Gc, and CIGB-EPO showed the greatest variety of high-mannose-phosphate structures. The sialylation and LacNAc extension patterns of the three ESAs were similar, with a maximum of four N-acetyl-neuraminic acid (Neu5Ac) moieties detected per glycan. Such differences in SA derivatisation, particularly O-acetylation, could have consequences for the quality and safety of a biotherapeutic, as well as its efficacy
Validity of a three-variable juvenile arthritis disease activity score in children with new-onset juvenile idiopathic arthritis
<p>Objectives To investigate the validity and feasibility of the Juvenile Arthritis Disease Activity Score (JADAS) in the routine clinical setting for all juvenile idiopathic arthritis (JIA) disease categories and explore whether exclusion of the erythrocyte sedimentation rate (ESR) from JADAS (the ‘JADAS3’) influences correlation with single markers of disease activity.</p>
<p>Methods JADAS-71, JADAS-27 and JADAS-10 were determined at baseline for an inception cohort of children with JIA in the Childhood Arthritis Prospective Study. JADAS3-71, JADAS3-27 and JADAS3-10 were determined using an identical formula but with exclusion of ESR. Correlation of JADAS with JADAS3 and single measures of disease activity/severity were determined by category.</p>
<p>Results Of 956 eligible children, sufficient data were available to calculate JADAS-71, JADAS-27 and JADAS-10 at baseline in 352 (37%) and JADAS3 in 551 (58%). The median (IQR) JADAS-71, JADAS-27 and JADAS-10 for all 352 children was 11 (5.9–18), 10.4 (5.7–17) and 11 (5.9–17.3), respectively. Median JADAS and JADAS3 varied significantly with the category (Kruskal–Wallis p=0.0001), with the highest values in children with polyarticular disease patterns. Correlation of JADAS and JADAS3 across all categories was excellent. Correlation of JADAS71 with single markers of disease activity/severity was good to moderate, with some variation across the categories. With the exception of ESR, correlation of JADAS3-71 was similar to correlation of JADAS-71 with the same indices.</p>
<p>Conclusions This study is the first to apply JADAS to all categories of JIA in a routine clinical setting in the UK, adding further information about the feasibility and construct validity of JADAS. For the majority of categories, clinical applicability would be improved by exclusion of the ESR.</p>
Single-vehicle collisions in Europe: analysis using real-world and crash-test data
A large proportion of European road casualties result when a vehicle leaves the main carriageway, often impacting roadside obstacles. As part of the EC-funded project, RISER (Roadside Infrastructure for Safer European Roads), a number of activities were undertaken to collate the type of data which is needed to understand the frequency and severity of real world crash situations and relate this to crash test data mandated in the EU. Accident data was collected and used to create a statistical database and a detailed database exclusively for single vehicle 'run-off the road' collisions on major rural (not urban) roads, simulation software was used to further understand impacts with roadside structures and an inventory of crash test data was collected for impacts with objects such as poles and safety barriers .
The combination of real world accident data, simulations and crash test data has provided a unique insight into the characteristics of single vehicle collisions, helping us to understand them better and make recommendations for consideration when drafting design guidelines. This information is crucial for those involved in the design and evaluation of the roadside environment
Agreement between proxy and adolescent assessment of disability, pain, and well-being in juvenile idiopathic arthritis.
OBJECTIVES: Adolescents with juvenile idiopathic arthritis have demonstrated substantial disagreement with their proxy's assessment of their disability, pain, and well-being. Our objective was to describe the clinical and psychological factors associated with discordance. STUDY DESIGN: This analysis included 204 proxy-adolescent (median age, 13 years) dyads that completed a Childhood Health Assessment Questionnaire for disability with 100-mm visual analogue scales for pain and well-being. Depressive symptoms in adolescents were measured by the Mood and Feelings Questionnaire and in proxies the General Health Questionnaire. Disagreement was assessed using Bland-Altman plots. Associations with discordance were identified using logistic regression analyses. RESULTS: There was higher agreement for disability (84%) than for pain (71%) and well-being (66%). Regression analyses found no association between age, sex, or disease duration and disagreement. However, relationships between disease activity and disagreement in outcomes were identified. Independent associations were found between increasing Mood and Feelings Questionnaire scores and disagreement in pain and well-being. CONCLUSIONS: Proxy and adolescent reports of pain and well-being are more likely to disagree in those with severe disease. Adolescents who report depressive symptoms are also more likely to disagree with their proxy. The reasons for these are multifactorial, and considerations of both reports are important when assessing outcomes in juvenile idiopathic arthritis
Hugs and behaviour points: alternative education and the regulation of 'excluded' youth
In England, alternative education (AE) is offered to young people formally excluded from school, close to formal exclusion or who have been informally pushed to the educational edges of their local school. Their behaviour is seen as needing to change. In this paper, we examine the behavioural regimes at work in 11 AE programmes. Contrary to previous studies and the extensive ‘best practice’ literature, we found a return to highly behaviourist routines, with talking therapeutic approaches largely operating within this Skinnerian frame. We also saw young people offered a curriculum largely devoid of languages, humanities and social sciences. What was crucial to AE providers, we argue, was that they could demonstrate 'progress' in both learning and behaviour to inspectors and systems. Mobilising insights from Foucault, we note the congruence between the external regimes of reward and punishment used in AE and the kinds of insecure work and carceral futures that might be on offer to this group of young people
Levels and equivalence in credit and qualifications frameworks: Contrasting the prescribed and enacted curriculum in school and college
Drawing on data from an empirical study of three matched subjects in upper secondary school and further education college in Scotland, this article explores some of the factors that result in differences emerging from the translation of the prescribed curriculum into the enacted curriculum. We argue that these differences raise important questions about equivalences which are being promoted through the development of credit and qualifications frameworks. The article suggests that the standardisation associated with the development of a rational credit and qualifications framework and an outcomes-based prescribed curriculum cannot be achieved precisely because of the multiplicity that emerges from the practices of translation
An exploration of the use of infant observation methods to research the identities of severely learning disabled adolescents and to enhance relationship-based practice for professional social work practice
This paper considers how infant observation methods may be adapted to explore and research the identities of severely learning disabled adolescents, a group of young people whose experiences are poorly represented in the literature. Through focusing on emotion and relationship, this ‘practice-near’ research method also offers a way for social workers to develop their reflective capacity in relation to the often hidden, uncomfortable emotions aroused by experiencing impairment and difference, but without the defences usually involved in assuming the professional role. The importance of taking time to get on a disabled child’s ‘wavelength’ is illustrated through extracts from the research which show how a young person’s agency and identity can be appreciated. The method also has the potential to develop social workers’ awareness of the powerful undercurrent of emotions apparent at times within families of severely disabled young people and tentative suggestions are made about the projective processes and hidden hostilities at work within one of the families observed as part of the research project. Professionals may be able to use this knowledge to become resilient and reflective practitioners and the observation method itself has something to offer by way of a containing experience for families
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