Fuel distribution measurements in a model low NOx double annular combustor using laser induced fluorescence

Planar laser induced fluorescence (PLIF) was employed in a three sector, low NOx double annular combustor in order to characterise the combusting fuel spray. Naphthalene was employed as a fluorescent agent in odourless kerosene in order to determine the behavior of the light fractions in the fuel vapour, and the light to medium fractions in the fuel spray, while 2,5 di-phenyl oxizol (ppo) was employed to determine the behavior of the heavy fractions in the fuel spray. Counter-swirl air blast atomizing fuel injectors employing a nominal fuel spray included cone angle of 90 deg were employed to inject the kerosene fuel into the double annular combustor. Radial and axial measurements were performed on the combusting spray. Spatial variations in fuel spray placement were observed, together with radial anisotropy

The optical characterisation of spray and soot formation in a diesel engine

Laser sheet drop-sizing (LSD) measurements of a Diesel spray and simultaneous laser induced incandescence/Mie scattering measurements of soot have been performed in an optically accessible, common rail, 1.9 litre, turbo-charged, direct injection Diesel engine. The diesel fuel injectors employed in this study were prototype five hole injectors, supplied by R. Bosch. An oxygenated surrogate Diesel fuel with an estimated cetane number of 54 was employed in order to reduce the amount of soot formed during combustion. The prototype five-hole injector employed produced spray jets that were distinguishable in terms of the liquid volume fraction, drop-size distribution and spray penetration distance produced. The soot volume fraction formed during combustion was found to be correlated with drop-size distribution, and local soot particle size distribution was observed to be inversely correlated with local soot volume fraction

A meta-narrative review of electronic patient records

This session comprises four papers that consider how systematic review methods may be developed in order to make the best use of complex evidence in education and health. The methods and approaches reflected upon in these papers are not drawn from a single research tradition, but share a common goal of broadening the methodological scope of systematic reviews and better understanding the utilisation of knowledge produced in this way. The first paper (Henry Potts) reports an ongoing review using a meta-narrative approach to make sense of the diverse sources of knowledge regarding electronic patient records. The review method has stressed the importance of understanding knowledge from within the research tradition in which it was produced; it is argued that this has important implications for the way that evidence is utilised in the policy making process. The second paper (Geoff Wong) reflects upon the experience of using an explicit realist approach in the synthesis of the evidence in Internet based learning. This realist synthesis offers a method of making sense of the highly heterogeneous and context dependent evidence which exists in this field thus enabling greater insights into what makes such educational interventions ‘work’. The third paper (Rod Sheaff) reports a review of the predominantly qualitative research literature on organisational structures and their impacts upon policy outcomes in health systems. A scoping study found 14389 relevant papers of which 1568 were selected for review. These studies were very variable in the amount and quality of the qualitative data, hence 'evidence', which they reported. The paper describes an attempt to adapt realist methods so as to synthesise such bodies of research in ways which take account of this variation in the strength of qualitative evidence. The fourth paper (Mark Pearson) draws upon the work of Donald Campbell and colleagues in order to gain a fuller understanding of how systematic reviews are utilised in the policy making process. It is argued that interpretive approaches to understanding policy making (such as rhetorical analysis) need to be tempered with a more nuanced understanding of research validity. The case is made that interpretive approaches not only can, but should, be melded with research validity to increase understanding of the policy making process

Fos co-operation with PTEN loss elicits keratoacanthoma not carcinoma due to p53/p21^WAF-induced differentiation triggered by GSK3b inactivation and reduced AKT activity

To investigate gene synergism in multistage skin carcinogenesis, the RU486-inducible cre/lox system was employed to ablate PTEN function [K14.cre/D5PTENflx] in mouse epidermis expressing activated v-fos [HK1.fos]. RU486-treated HK1.fos/D5PTENflx mice exhibited hyperplasia, hyperkeratosis and tumours that progressed to highly differentiated keratoacanthomas rather than carcinomas, due to re-expression of high p53 and p21WAF levels. Despite elevated MAP kinase activity, cyclin D1/E2 over expression and increased AKT activity forming areas of highly proliferative, papillomatous keratinocytes, increasing levels of GSK3b inactivation exceeded a threshold that induced p53/p21WAF expression to halt proliferation and accelerate differentiation, giving the hallmark keratosis of keratoacanthomas. A pivotal facet to this GSK3b-triggered mechanism centred on increasing p53 expression in basal layer keratinocytes. This reduced activated AKT expression and released inhibition of p21WAF, which accelerated keratinocyte differentiation, as indicated by unique basal layer expression of differentiation-specific keratin K1, alongside premature filaggrin and loricrin expression. Thus, fos synergism with PTEN loss elicited a benign tumour context where GSK3b-induced, p53/p21WAF expression continually switched AKT-associated proliferation into one of differentiation, preventing further progression. This putative compensatory mechanism required the critical availability of normal p53 and/or p21WAF otherwise deregulated fos, Akt and GSK3b associate with malignant progression

Risk models and scores for type 2 diabetes: Systematic review

This article is published under a Creative Commons Attribution Non Commercial (CC BY-NC 3.0) licence that allows reuse subject only to the use being non-commercial and to the article being fully attributed (http://creativecommons.org/licenses/by-nc/3.0).Objective - To evaluate current risk models and scores for type 2 diabetes and inform selection and implementation of these in practice. Design - Systematic review using standard (quantitative) and realist (mainly qualitative) methodology. Inclusion - criteria Papers in any language describing the development or external validation, or both, of models and scores to predict the risk of an adult developing type 2 diabetes. Data sources - Medline, PreMedline, Embase, and Cochrane databases were searched. Included studies were citation tracked in Google Scholar to identify follow-on studies of usability or impact. Data extraction - Data were extracted on statistical properties of models, details of internal or external validation, and use of risk scores beyond the studies that developed them. Quantitative data were tabulated to compare model components and statistical properties. Qualitative data were analysed thematically to identify mechanisms by which use of the risk model or score might improve patient outcomes. Results - 8864 titles were scanned, 115 full text papers considered, and 43 papers included in the final sample. These described the prospective development or validation, or both, of 145 risk prediction models and scores, 94 of which were studied in detail here. They had been tested on 6.88 million participants followed for up to 28 years. Heterogeneity of primary studies precluded meta-analysis. Some but not all risk models or scores had robust statistical properties (for example, good discrimination and calibration) and had been externally validated on a different population. Genetic markers added nothing to models over clinical and sociodemographic factors. Most authors described their score as “simple” or “easily implemented,” although few were specific about the intended users and under what circumstances. Ten mechanisms were identified by which measuring diabetes risk might improve outcomes. Follow-on studies that applied a risk score as part of an intervention aimed at reducing actual risk in people were sparse. Conclusion - Much work has been done to develop diabetes risk models and scores, but most are rarely used because they require tests not routinely available or they were developed without a specific user or clear use in mind. Encouragingly, recent research has begun to tackle usability and the impact of diabetes risk scores. Two promising areas for further research are interventions that prompt lay people to check their own diabetes risk and use of risk scores on population datasets to identify high risk “hotspots” for targeted public health interventions.Tower Hamlets, Newham, and City and Hackney primary care trusts and National Institute of Health Research

SDE SIS epidemic model with demographic stochasticity and varying population size

In this paper we look at the two dimensional stochastic differential equation (SDE) susceptible-infected-susceptible (SIS) epidemic model with demographic stochasticity where births and deaths are regarded as stochastic processes with per capita disease contact rate depending on the population size. First we look at the SDE model for the total population size and show that there exists a unique non-negative solution. Then we look at the two dimensional SDE SIS model and show that there exists a unique non-negative solution which is bounded above given the total population size. Furthermore we show that the number of infecteds and the number of susceptibles become extinct in finite time almost surely. Lastly, we support our analytical results with numerical simulations using theoretical and realistic disease parameter values

An examination of business occupier relocation decision making : distinguishing small and large firm behaviour

This paper explores how business occupiers decide whether and where to relocate. It captures the experience and behaviour of a range of sizes and types of business occupier and subjects their decision-making processes to detailed scrutiny. A linear three-stage decision model is used to sequence and structure interviews with individuals who have intimate involvement with the relocation of 28 firms and organizations in Tyne and Wear, in the north-east of England. The 'constant comparative' method is used to analyse the interview data, from which emerges 18 key concepts, comprising 51 characteristic components. Using an axial approach, these are organized into 10 cross-cutting themes that represent the main areas of consideration or influence on the thinking of the people involved in determining whether a firm or organization should relocate and, if so, where to. The resulting analysis finds that organizations adopt varying degrees of sophistication when making relocation decisions; small firms are more inclined to make decisions based on constrained information; larger organizations adopt a more complex approach. Regardless of firm size, key individuals exert considerable influence over the decision-making process and its outcome

Caring for the patient, caring for the record: an ethnographic study of ‘back office’ work in upholding quality of care in general practice

The quality of information recorded about patient care is considered key to improving the overall quality, safety and efficiency of patient care. Assigning codes to patients' records is an important aspect of this documentation. Current interest in large datasets in which individual patient data are collated (e.g. proposed NHS care.data project) pays little attention to the details of how 'data' get onto the record. This paper explores the work of summarising and coding records, focusing on 'back office' practices, identifying contributors and barriers to quality of care.Ethnographic observation (187 hours) of clinical, management and administrative staff in two UK general practices with contrasting organisational characteristics. This involved observation of working practices, including shadowing, recording detailed field notes, naturalistic interviews and analysis of key documents relating to summarising and coding. Ethnographic analysis drew on key sensitizing concepts to build a 'thick description' of coding practices, drawing these together in a narrative synthesis.Coding and summarising electronic patient records is complex work. It depends crucially on nuanced judgements made by administrators who combine their understanding of: clinical diagnostics; classification systems; how healthcare is organised; particular working practices of individual colleagues; current health policy. Working with imperfect classification systems, diagnostic uncertainty and a range of local practical constraints, they manage a moral tension between their idealised aspiration of a 'gold standard' record and a pragmatic recognition that this is rarely achievable in practice. Adopting a range of practical workarounds, administrators position themselves as both formally accountable to their employers (general practitioners), and informally accountability to individual patients, in a coding process which is shaped not only by the 'facts' of the case, but by ongoing working relationships which are co-constructed alongside the patient's summary.Data coding is usually conceptualised as either a technical task, or as mundane, routine work, and usually remains invisible. This study offers a characterisation of coding as a socially complex site of moral work through which new lines of accountability are enacted in the workplace, and casts new light on the meaning of coded data as conceptualised in the 'quality of care' discourse