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We are investigating a novel enrichment process that could allow the use of industrial complementary metal–oxide–semiconductor implanters to manufacture "quantum grade" 28Si layers for use in quantum computers. Our implanted layer exchange enrichment process leverages conventional deposition-based layer exchange approaches but replaces a step of depositing a Si layer above an Al layer with a 28Si implant into the top of an Al layer. A subsequent anneal dissolves Si into Al beneath the implanted region where Si diffuses and either epitaxially grows onto the substrate or forms poly-crystals in the Al [Schneider and England, ACS Appl. Mater. Interfaces 15, 21609 (2023)]. We have developed a qualitative model using simple assumptions and boundary conditions to estimate characteristic times and rates of epitaxy or poly-crystallization for this novel layer exchange process. We have used the model to explain crystallization outcomes reported in this paper and previously. We find that the absence of an oxide boundary layer separating Si and Al allows Si diffusion to become established within the first second of all the anneals studied and that crystallization actually completes during the temperature ramp of most of the anneals. The rapid evolution of Si supersaturation in Al beneath the implanted layer explains the ratios of epitaxial growth to poly-crystallization observed after these anneals. We use this understanding to propose the implant layer exchange conditions that could produce the highest quality mono-crystalline quantum grade Si. [ABSTRACT FROM AUTHOR]

Population-level disease risk varies in space and time, and is typically estimated using aggregated disease count data relating to a set of non-overlapping areal units for multiple consecutive time periods. A large research base of statistical models and corresponding software has been developed for such data, with most analyses being undertaken in a Bayesian setting using either Markov chain Monte Carlo (MCMC) simulation or integrated nested Laplace approximations (INLA). This paper presents a tutorial for undertaking spatio-temporal disease modelling using MCMC simulation, utilising the CARBayesST package in the R software environment. The tutorial describes the complete modelling journey, starting with data input, wrangling and visualisation, before focusing on model fitting, model assessment and results presentation. It is illustrated by a new case study of pneumonia mortality at the local authority level in England, and answers important public health questions including the effect of covariate risk factors, spatio-temporal trends, and health inequalities., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This paper describes the collaborative process of building a simulation model in order to understand patient waiting times in an accident and emergency department. The purpose is to explore the issues that arise when involving clients, in this case health care professionals, in the process of model building. The study background and a detailed account of the modelling process are presented. The focus of the paper is on some general themes that can be discovered running through the process. These offer some tentative insights into client involvement in system dynamics modelling, in particular its application in health care. Given this study's first promising results, further collaborative studies are encouraged. [ABSTRACT FROM AUTHOR]

Multicomponent injection molding often combines a stiff thermoplastic material with a thermoplastic elastomer or thermoplastic vulcanite. Recently, for high‐demanding applications, a novel process has been developed to replace these thermoplastic elastomers or vulcanite with a thermoset rubber, for example, NBR or EPDM. One of the most important properties of a two component product is an adequate adhesion between both components. This paper describes a method, which combines experiments and numerical simulations to predict the adhesion strength between a thermoplastic, semicrystalline HDPE, and an EPDM thermoset rubber. This method uses numerical simulations of the interfacial temperature and the local degree of cure. The local interface temperature is combined with the results of DSC measurements to predict the degree of melting, subsequently linked to the ability to develop adhesive strength. The degree of cure is used to determine the local rubber strength. The combination of the given data will be used to predict interfacial strength. The results obtained by proposed numerical strategy have been successfully validated with experimental data on a simple plate product. POLYM. ENG. SCI., 59:1489–1498 2019. © 2019 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

This paper presents highlights from research conducted at the University of Liverpool to deteimine suitable fidelity criteria and guidelines for the modelling and simulation of the helicopter-ship dynamic interface environment. The paper begins by describing the characteristics of the helicopter-ship dynamic interface, explaining the motivation behind the research and reviewing the state-of-the-art in dynamic interface simulation. The development of a dynamic interface research environment based on an existing research simulator operated by the University of Liverpool is then described, before key results from a number of piloted simulation experiments are presented. These experiments were specifically designed to address fidelity sensitivity issues, such as, are unsteady airwake models necessary, or can a steady airwake model induce appropriate levels of pilot workload? What influence does the modelled ship geometry, or choice of atmospheric wind conditions have on the airwake model and on pilot workload? Finally, the paper concludes by briefly describing the relevance of these research findings to current and future industry programmes. [ABSTRACT FROM AUTHOR]

This paper suggests that computer simulation modelling can offer opportunities for redistributing expertise between science and affected publics in relation to environmental problems. However, in order for scientific modelling to contribute to the coproduction of new knowledge claims about environmental processes, scientists need to reposition themselves with respect to their modelling practices. In the paper we examine a process in which two hydrological modellers became part of an extended research collective generating new knowledge about flooding in a small rural town in the UK. This process emerged in a project trialling a novel participatory research apparatus-competency groups-aiming to harness the energy generated in public controversy and enable other than scientific expertise to contribute to environmental knowledge. Analysing the process repositioning the scientists in terms of a dynamic of 'dissociation' and 'attachment', we map the ways in which prevailing alignments of expertise were unravelled and new connections assembled, in relation to the matter of concern. We show how the redistribution of knowledge and skills in the extended research collective resulted in a new computer model, embodying the coproduced flood risk knowledge. [ABSTRACT FROM AUTHOR]

Computer-Aided Assessments (CAAs) have been used increasingly at Brunel University for over 10 years to test students' mathematical abilities. Recently, we have focussed on providing very rich feedback to the students; given the work involved in designing and coding such feedback, it is important to study the impact of the interaction between students and feedback. To make feedback more focussed, examination scripts have been analysed to identify common student errors and misconceptions. These have then been used to code distracters in multiple-choice and responsive numerical input-type questions. Since random parameters are used in all questions developed, distracters have to be coded as algebraic or algorithmic mal-rules. This paper reports on the methodology used to identify students' errors and misconceptions and how the evidence collected was used to code the distracters. The paper also provides hard evidence that real learning has taken place while students have interacted with the CAAs. Statistical analyses of exam performance over eight years indicate that students are able to improve performance in subsequent formative and summative assessments provided that they have truly engaged with the CAA, especially by spending time studying the feedback provided. [ABSTRACT FROM AUTHOR]

This paper challenges three assumptions common in the literature on expertise: that expertise is linearly derived from scientific knowledge; that experts always align with the established institutional order; and that expertise is a property acquired by individuals. We criticize these ideas by juxtaposing three distinct expert practices involved with flood risk management in England. Virtual engineering is associated with commercial consultancy and relies on standardized software packages to assess local flood inundation. Mathematical experimentation refers to academic scientists creating new digital renderings of the physical dynamics of flooding. Participatory modeling denotes research projects that aim to transform the relationships between experts and local communities. Focusing on different modes of modeling we contribute an analysis of how particular models articulate with specific politics of knowledge as experts form relationships with flood risk management actors. Our empirical study also shows how models can contribute to re-distribution of expertise in local flood risk management.

It is uncommon for risk groups defined by statistical or artificial intelligence (AI) models to be chosen by jointly considering model performance and potential interventions available. We develop a framework to rapidly guide choice of risk groups in this manner, and apply it to guide breast cancer screening intervals using an AI model. Linear programming is used to define risk groups that minimize expected advanced cancer incidence subject to resource constraints. In the application risk stratification performance is estimated from a case–control study (2044 cases, 1:1 matching), and other parameters are taken from screening trials and the screening programme in England. Under the model, re-screening in 1 year for the highest 4% AI model risk, in 3 years for the middle 64%, and in 4 years for 32% of the population at lowest risk, was expected to reduce the number of advanced cancers diagnosed by approximately 18 advanced cancers per 1000 diagnosed with triennial screening, for the same average number of screens in the population as triennial screening for all. Sensitivity analyses found the choice of thresholds was robust to model parameters, but the estimated reduction in advanced cancers was not precise and requires further evaluation. Our framework helps define thresholds with the greatest chance of success for reducing the population health burden of cancer when used in risk-adapted screening, which should be further evaluated such as in health-economic modelling based on computer simulation models, and real-world evaluations. [ABSTRACT FROM AUTHOR]

This paper uses a symbiotic adaptive neuro-evolutionary algorithm to breed neural network models for the River Ouse catchment. It advances on traditional evolutionary approaches by evolving and optimising individual neurons. Furthermore, it is ideal for experimentation with alternative objective functions. Recent research suggests that sum squared error may not result in the most appropriate models from a hydrological perspective. Models are bred for lead times of 6 and 24 hours and compared with conventional neural network models trained using backpropagation. The algorithm is also modified to use different objective functions in the optimisation process: mean squared error, relative error and the Nash-Sutcliffe coefficient of efficiency. The results show that at longer lead times the evolved neural networks outperform the conventional ones in terms of overall performance. It is also shown that the sum squared error objective function does not result in the best performing model from a hydrological perspective.

It is recognised that Visual Impact Assessment (VIA), unlike many other aspects of Environmental Impact Assessments (EIA), relies less upon measurement than upon experience and judgement. Hence, it is necessary for a more structured and consistent approach towards VIA, reducing the amount of bias and subjectivity. For proposed developments, there are very few quantitative techniques for the evaluation of visibility, and these existing methods can be highly inaccurate and time consuming. Percentage view changes are one of the few quantitative techniques, and the use of computer technology can reduce the inaccuracy and the time spent evaluating the visibility of either existing or proposed developments. For over 10 years, research work undertaken by the authors at the University of Nottingham has employed Computer Graphics (CG) and Virtual Reality (VR) in civilian and industrial contexts for environmental planning, design visualisation, accident reconstruction, risk analysis, data visualisation and training simulators. This paper describes a method to quantitatively assess the visual impact of proposed developments on the landscape using CG techniques. This method allows the determination of accurate percentage view changes with the use of a computer-generated model of the environment and the application of specialist software that has been developed at the University of Nottingham. The principles are easy to understand and therefore planners, authorisation agencies and members of the public can use and understand the results. A case study is shown to demonstrate the application and the capabilities of the technology.

This paper reports the processes and initial outcomes of a pilot study which investigated a week long 'virtual' children's ward experience for nursing students. Providing sufficient and meaningful experiences which enable students to quickly and effectively achieve competence in diverse areas of practice is often frustrated by the realities of available clinical experiences. Our response to this challenge was to more fully exploit and evaluate technologies which can be used to provide these learning experiences. Students experienced 'real time' scenario based work involving SIM-MAN; interactive information technology scenarios, critical incidents, master classes, video conferencing, and observational skill development exercises. Evaluation methodologies included observation of student performance, competence self rating scales; analysis of videotaped performance episodes and other data generated through the learning activities and lived experience accounts of participants. Initial findings indicate (1) statistically significant improvements in student competence measured through self reports; and (2) evidence of improvement gleaned from observed accounts, video analysis and qualitative evaluative comments. The final outcomes, including work with a control group, will be available for Conference.

Two-dimensional flood inundation modelling is a widely used tool to aid flood risk management. In urban areas, the model spatial resolution required to represent flows through a typical street network often results in an impractical computational cost at the city scale. This paper presents the calibration and evaluation of a recently developed formulation of the LISFLOOD-FP model, which is more computationally efficient at these resolutions. Aerial photography was available for model evaluation on 3 days from the 24 to the 31 of July. The new formulation was benchmarked against the original version of the model at 20 and 40 m resolutions, demonstrating equally accurate simulation, given the evaluation data but at a 67 times faster computation time. The July event was then simulated at the 2 m resolution of the available airborne LiDAR DEM. This resulted in more accurate simulation of the floodplain drying dynamics compared with the coarse resolution models, although maximum inundation levels were simulated equally well at all resolutions tested. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the development of the Learning in Virtual Environments programme (LIVE), carried out in special education over the last four years. It is more precisely a project chronology, so that the reader can sense the historical development of the programme rather than giving emphasis to any one particular feature or breakthrough, which are covered in other papers and available through the authors. The project conception in a special school in Nottingham is followed by a description of the development of experiential and communicational virtual learning environments. These are followed, in turn, by the results of our testing programmes which show that experience gained in a virtual environment can transfer to the real world and that their use can encourage self-directed activity in students with severe learning difficulties. Also included is a discussion of the role of virtual learning environments (VLEs) in special education and of its attributes in the context of contemporary educational theory.

Background: models projecting future disease burden have focussed on one or two diseases. Little is known on how risk factors of younger cohorts will play out in the future burden of multi-morbidity (two or more concurrent long-term conditions). Design: a dynamic microsimulation model, the Population Ageing and Care Simulation (PACSim) model, simulates the characteristics (sociodemographic factors, health behaviours, chronic diseases and geriatric conditions) of individuals over the period 2014-2040. Population: about 303,589 individuals aged 35 years and over (a 1% random sample of the 2014 England population) created from Understanding Society, the English Longitudinal Study of Ageing, and the Cognitive Function and Ageing Study II. Main outcome measures: the prevalence of, numbers with, and years lived with, chronic diseases, geriatric conditions and multi-morbidity. Results: between 2015 and 2035, multi-morbidity prevalence is estimated to increase, the proportion with 4+ diseases almost doubling (2015:9.8%; 2035:17.0%) and two-thirds of those with 4+ diseases will have mental ill-health (dementia, depression, cognitive impairment no dementia). Multi-morbidity prevalence in incoming cohorts aged 65-74 years will rise (2015:45.7%; 2035:52.8%). Life expectancy gains (men 3.6 years, women: 2.9 years) will be spent mostly with 4+ diseases (men: 2.4 years, 65.9%; women: 2.5 years, 85.2%), resulting from increased prevalence of rather than longer survival with multi-morbidity. Conclusions: our findings indicate that over the next 20 years there will be an expansion of morbidity, particularly complex multi-morbidity (4+ diseases). We advocate for a new focus on prevention of, and appropriate and efficient service provision for those with, complex multi-morbidity. [ABSTRACT FROM AUTHOR]

Objectives: While there has been significant research on the pressures facing acute hospitals during the COVID-19 pandemic, there has been less interest in downstream community services which have also been challenged in meeting demand. This study aimed to estimate the theoretical cost-optimal capacity requirement for 'step down' intermediate care services within a major healthcare system in England, at a time when considerable uncertainty remained regarding vaccination uptake and the easing of societal restrictions. Methods: Demand for intermediate care was projected using an epidemiological model (for COVID-19 demand) and regressing upon public mobility (for non-COVID-19 demand). These were inputted to a computer simulation model of patient flow from acute discharge readiness to bedded and home-based Discharge to Assess (D2A) intermediate care services. Cost-optimal capacity was defined as that which yielded the lowest total cost of intermediate care provision and corresponding acute discharge delays. Results: Increased intermediate care capacity is likely to bring about lower system-level costs, with the additional D2A investment more than offset by substantial reductions in costly acute discharge delays (leading also to improved patient outcome and experience). Results suggest that completely eliminating acute 'bed blocking' is unlikely economical (requiring large amounts of downstream capacity), and that health systems should instead target an appropriate tolerance based upon the specific characteristics of the pathway. Conclusions: Computer modelling can be a valuable asset for determining optimal capacity allocation along the complex care pathway. With results supporting a Business Case for increased downstream capacity, this study demonstrates how modelling can be applied in practice and provides a blueprint for use alongside the freely-available model code. [ABSTRACT FROM AUTHOR]

This paper challenges three assumptions common in the literature on expertise: that expertise is linearly derived from scientific knowledge; that experts always align with the established institutional order; and that expertise is a property acquired by individuals. We criticize these ideas by juxtaposing three distinct expert practices involved with flood risk management in England. Virtual engineering is associated with commercial consultancy and relies on standardized software packages to assess local flood inundation. Mathematical experimentation refers to academic scientists creating new digital renderings of the physical dynamics of flooding. Participatory modeling denotes research projects that aim to transform the relationships between experts and local communities. Focusing on different modes of modeling we contribute an analysis of how particular models articulate with specific politics of knowledge as experts form relationships with flood risk management actors. Our empirical study also shows how models can contribute to re-distribution of expertise in local flood risk management. [ABSTRACT FROM PUBLISHER]

This paper discusses computer simulation modelling in the context of environmental risk management. Approaching computer simulation as practice, performed in networks of heterogeneous elements, we examine the modelling undertaken by engineering consultants commissioned to provide knowledge about local flood risk to the Environment Agency of England and Wales (EA), the public body responsible for flood risk management. We propose that this simulation modelling is best understood as a form of engineering, work geared to solving the problems of clients. It is also a 'virtual' activity, articulating risks and possibilities in the digital space of the computer. We find that this 'virtual engineering' is shaped by the demands and protocols of the EA, first, by the establishment of long-term contractual agreements for delivering knowledge and second, by an EA requirement to use particular software packages. Fashioned between long-term contracts and black-boxed software virtual engineering becomes stabilised as 'the' way in which knowledge about flood risk in actual localities is generated and, consequently, becomes 'hard-wired' into flood risk management in England. [ABSTRACT FROM AUTHOR]

Abstract: Traditionally, researchers have employed statistical methods to model crime. However, these approaches are limited by being unable to model individual actions and behaviour. Brantingham and Brantingham (1993) described that in their opinion a useful and productive model for simulating crime would have the ability to model the occurrence of crime and the motivations behind it both temporally and spatially. This paper presents the construction and application of an agent-based model (ABM) for simulating occurrences of residential burglary at an individual level. It presents a novel framework that allows both human and environmental factors to be simulated. Although other agent-based models of crime do exist, this research represents the first working example of integrating a behavioural framework into an ABM for the simulation of crime. An artificial city, loosely based on the real city of Leeds, UK, and an artificial population were constructed, and experiments were run to explore the potential of the model to realistically simulate the main processes and drivers within this system. The results are highly promising, demonstrating the potential of this approach for both understanding processes behind crime and improving policies and developing effective crime prevention strategies. [Copyright &y& Elsevier]

Abstract: Masonry structures may be modelled as an assembly of linearly elastic bodies (individual bricks or stone-blocks) in unilateral frictional contact. Such models generally constitute a formidable computational challenge owing to the need to resolve interactions between individual bodies, such as detection of crack and openings and the resolution of non-linear equations governing the contact. Even for medium size structures, the large number of blocks from which they are assembled renders a full direct simulation of such structures practically impossible. In this paper, an adaptive multi-scale technique for the modelling of large-scale dynamic structures is implemented and applied to the computer simulation of Clare College Bridge, in Cambridge, UK. The adaptive multi-scale approach enables us to carry out simulations at a complexity normally associated with the cost of modelling the entire structure by a simple continuum model whilst incorporating small scale effects, such as openings of gaps and slippage between individual masonry units, using a systematic and locally optimal criterion. [Copyright &y& Elsevier]

An approach that incorporates three modelling components has been developed to estimate road traffic CO2 emissions for an urban area with street level resolution. The first component enables the determination of the road traffic characteristics using the SATURN (Simulation and Assignment of Traffic in Urban Road Networks) model. The output from this component is then analysed using MATrix LABoratory (MATLAB) programming to provide estimates of CO2 emissions for the urban area. Finally, ArcGIS is used to illustrate the model output. The three components are integrated using a Loose-Coupling approach in which the individual components each load the necessary data to give an independent output. The model structure is discussed in the current paper and the modelling results for a small city (Norwich, UK) are presented. [Copyright &y& Elsevier]

A computer simulation has been developed at The University of Sheffield that predicts the impact performance of roadway wire rope safety fences. Effective use of this simulation for design, or other purposes, requires it to be validated by showing that the predicted vehicle motion and fence response closely represent that of the real system. Two distinct validation studies are described in the current paper. The first compares the major results of eight impact tests undertaken at the UK Motor Industry Research Association and a further four impact tests undertaken at the Swedish Road and Transport Research Institute with the simulation predictions. The close prediction of the test results validates the use of the simulation as a design tool for a range of fence designs and impact conditions. The second validation study compares, in detail, the test results and simulation prediction for a single test. This suggests that, if required, results may be improved further by considering suspension effects in the vehicle model, and by a better understanding of frictional effects at the rope-post and the rope-vehicle contacts. [ABSTRACT FROM AUTHOR]

Background: An established finding suggests that, in balancing variability in patient demand and length of stay, an average bed occupancy of 85% should be targeted for acute hospital wards. The notion is that higher figures result in excessive capacity breaches, while anything lower fails to make economic use of available resources. Although concerns have previously been raised regarding the generic use of the 85% target, there has been little research interest into alternative derivations that may better represent the diverse range of conditions that exist in practice.Objective: To quantify a continuum of average occupancy targets for use within the acute hospital setting.Methods: Computer simulation is used to model the process of acute patient admission and discharge. Patient arrivals are assumed to be independent of one another (i.e. random) with length of stay distributions obtained through fitting to patient-level data from all of England.Results: Target average occupancy increases with ward size, ranging from 45% to 79% for a relatively small 15-bed ward to 64-84% for a relatively large 50-bed ward. Regarding ward speciality, for a typical 25-bed ward, values range from 57-58% for Gynaecology to 67-74% for Adult Mental Health. These increase to 62-63% and 75-82%, respectively, if the tolerance on breaching capacity is relaxed from 2% to 5% of days per year.Conclusion: An unconditional 85% target serves as an overestimate across the vast majority of settings that typically exist in practice. Hospital planners should consider ward size, speciality and capacity-breach tolerance in determining a more sensitive assessment of bed occupancy requirements. This study provides hospital planners with a means to reliably assess the operational performance and readily calculate optimal capacity requirements. [ABSTRACT FROM AUTHOR]

A reductio ad absurdum argument is used to establish that a universal computer cannot exist. The proof uses a recursive process whereby an assumed universal computer attempting to simulate itself descends into an infinite regress. Appealing to a more powerful computer to do the simulation leads to the same unavoidable conclusion. [ABSTRACT FROM AUTHOR]

The proportional hazards model represents the most commonly assumed hazard structure when analysing time to event data using regression models. We study a general hazard structure which contains, as particular cases, proportional hazards, accelerated hazards, and accelerated failure time structures, as well as combinations of these. We propose an approach to apply these different hazard structures, based on a flexible parametric distribution (exponentiated Weibull) for the baseline hazard. This distribution allows us to cover the basic hazard shapes of interest in practice: constant, bathtub, increasing, decreasing, and unimodal. In an extensive simulation study, we evaluate our approach in the context of excess hazard modelling, which is the main quantity of interest in descriptive cancer epidemiology. This study exhibits good inferential properties of the proposed model, as well as good performance when using the Akaike Information Criterion for selecting the hazard structure. An application on lung cancer data illustrates the usefulness of the proposed model. [ABSTRACT FROM AUTHOR]

Background: Air pollution damages health by promoting the onset of some non-communicable diseases (NCDs), putting additional strain on the National Health Service (NHS) and social care. This study quantifies the total health and related NHS and social care cost burden due to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) in England.Method and Findings: Air pollutant concentration surfaces from land use regression models and cost data from hospital admissions data and a literature review were fed into a microsimulation model, that was run from 2015 to 2035. Different scenarios were modelled: (1) baseline 'no change' scenario; (2) individuals' pollutant exposure is reduced to natural (non-anthropogenic) levels to compute the disease cases attributable to PM2.5 and NO2; (3) PM2.5 and NO2 concentrations reduced by 1 μg/m3; and (4) NO2 annual European Union limit values reached (40 μg/m3). For the 18 years after baseline, the total cumulative cost to the NHS and social care is estimated at £5.37 billion for PM2.5 and NO2 combined, rising to £18.57 billion when costs for diseases for which there is less robust evidence are included. These costs are due to the cumulative incidence of air-pollution-related NCDs, such as 348,878 coronary heart disease cases estimated to be attributable to PM2.5 and 573,363 diabetes cases estimated to be attributable to NO2 by 2035. Findings from modelling studies are limited by the conceptual model, assumptions, and the availability and quality of input data.Conclusions: Approximately 2.5 million cases of NCDs attributable to air pollution are predicted by 2035 if PM2.5 and NO2 stay at current levels, making air pollution an important public health priority. In future work, the modelling framework should be updated to include multi-pollutant exposure-response functions, as well as to disaggregate results by socioeconomic status. [ABSTRACT FROM AUTHOR]

Introduction Coronary heart disease (CHD) remains a leading cause of UK mortality. Dietary trans fats (TFA) represent a powerful CHD risk factor. However, UK efforts to reduce intake have been less successful than other nations. We modelled the potential health and economic effects of eliminating industrial and all TFA up to 2020. Methods We extended the previously validated IMPACTsec model, to estimate the potential effects on health and economic outcomes of mandatory reformulation or a complete ban on dietary TFA in England and Wales from 2011 to 2020. We modelled two policy scenarios: 1) Elimination of industrial TFA consumption, from 0.8% to 0.4% daily energy 2) Elimination of all TFA consumption, from 0.8% to 0% Results Elimination of industrial TFA across the England and Wales population could result in approximately 1600 fewer deaths per year, with some 4000 fewer hospital admissions; gaining approximately 14 000 additional life years. Health inequalities would be substantially reduced in both scenarios. Elimination of industrial TFA would be cost saving. This would include approximately £100m saved in direct healthcare costs. Elimination of all TFA would double the health and economic gains. Conclusions Eliminating industrial or all UK dietary intake of TFA could substantially reduce CHD mortality and inequalities, while resulting in substantial annual savings. [ABSTRACT FROM AUTHOR]

The article presents a study which investigated unwarranted variation in ventilation tube insertions for otitis media with effusion in children in England. Topics include derivation of estimates using Monte Carlo simulation, expected number of children that would be expected to benefit from ventilation tubes for otitis media with effusion yearly, and the observed number of ventilation tubes for otitis media with effusion-associated diagnoses.

Background Obesity care services are often faced with the need to adapt their resources to rising levels of demand. The main focus of this study was to help prioritise planned investments in new capacity allowing the service to improve patient experience and meet future anticipated demand. Methods We developed computer models of patient flows in an obesity service in an Academic Health Science Centre that provides lifestyle, pharmacotherapy and surgery treatment options for the UK's National Health Service. Using these models we experiment with different scenarios to investigate the likely impact of alternative resource configurations on patient waiting times. Results Simulation results show that the timing and combination of adding extra resources (eg, surgeons and physicians) to the service are important. For example, increasing the capacity of the pharmacotherapy clinics equivalent to adding one physician reduced the relevant waiting list size and waiting times, but it then led to increased waiting times for surgical patients. Better service levels were achieved when the service operates with the resource capacity of two physicians and three surgeons. The results obtained from this study had an impact on the planning and organisation of the obesity service. Conclusions Resource configuration combined with demand management (reduction in referral rates) along the care service can help improve patient waiting time targets for obesity services, such as the 18 week target of UK's National Health Service. The use of simulation models can help stakeholders understand the interconnectedness of the multiple microsystems (eg, clinics) comprising a complex clinical service for the same patient population, therefore, making stakeholders aware of the likely impact of resourcing decisions on the different microsystems. [ABSTRACT FROM AUTHOR]

Objective:To produce a high-resolution, three-dimensional temporal bone model from serial sections, using a personal computer.Method:Digital images were acquired from histological sections of the temporal bone. Image registration, segmentation and three-dimensional volumetric reconstruction were performed using a personal computer. The model was assessed for anatomical accuracy and interactivity by otologists.Results:An accurate, high-resolution, three-dimensional model of the temporal bone was produced, containing structures relevant to otological surgery. The facial nerve, labyrinth, internal carotid artery, jugular bulb and all of the ossicles were seen (including the stapes footplate), together with the internal and external auditory meati. Some projections also showed the chorda tympani nerve.Conclusion:A high-resolution, three-dimensional computer model of the complete temporal bone was produced using a personal computer. Because of the increasing difficulty in procuring cadaveric bones, this model could be a useful adjunct for training. [ABSTRACT FROM PUBLISHER]

Infection control for hospital pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) often takes the form of a package of interventions, including the use of patient isolation and decolonization treatment. Such interventions, though widely used, have generated controversy because of their significant resource implications and the lack of robust evidence with regard to their effectiveness at reducing transmission. The aim of this study was to estimate the effectiveness of isolation and decolonization measures in reducing MRSA transmission in hospital general wards. Prospectively collected MRSA surveillance data from 10 general wards at Guy's and St. Thomas' hospitals, London, United Kingdom, in 2006–2007 were used, comprising 14,035 patient episodes. Data were analyzed with a Markov chain Monte Carlo algorithm to model transmission dynamics. The combined effect of isolation and decolonization was estimated to reduce transmission by 64% (95% confidence interval: 37, 79). Undetected MRSA-positive patients were estimated to be the source of 75% (95% confidence interval: 67, 86) of total transmission events. Isolation measures combined with decolonization treatment were strongly associated with a reduction in MRSA transmission in hospital general wards. These findings provide support for active methods of MRSA control, but further research is needed to determine the relative importance of isolation and decolonization in preventing transmission. [ABSTRACT FROM PUBLISHER]

The rapid spread of the new influenza virus A(H1N1)v in young age groups in 2009 has been partly attributed to a high transmission intensity in schools. However, detailed characterization of the spread of influenza in school populations has been difficult to obtain, simply because it is very hard to identify who infected whom in a large outbreak. Data collected in large outbreak investigations typically miss many transmission events, and some reported transmission events will be incorrect. Here the authors present robust likelihood-based methods that can be used to analyze outbreak data while explicitly accounting for both missing data and erroneous data. They apply this method to a school-based outbreak of pandemic influenza A(H1N1)v that occurred in London, United Kingdom, in April 2009. The authors show that the generation interval in this school-based population was 2.20 days and that the reproduction number declined coincident with school closure, from 1.33 secondary cases per primary case to 0.43 secondary cases per primary case. These results provide quantitative evidence for the change in influenza transmission that is to be expected from school closure. [ABSTRACT FROM PUBLISHER]

When planners intervene in urban systems they seek in part to generate a positive response from those parts of a city outside of their control, namely the private market and private individuals. This response is difficult to predict due to the fact that the city is a nonlinear system of organized complexity. Models of cities which seek to explain this response are necessarily complicated and dynamic. Where an analytical solution is not possible we turn to computer simulation and interactive visualization in order to understand their output. Allowing human participation in such simulations provides a sandbox in which to experiment with the dynamic behaviour of an urban model and play a part in its evolution. Two possible options for structuring this participation are: (1) toy retail systems, which allow unconstrained experimentation, and (2) games, which impose rules and involve role-play and competition. To explore these ideas we construct a toy retail system and a two-player retail game, both of which are derived from an existing agent-based retail model. We explore the application of these systems to the metropolitan county of South Yorkshire in the UK. [ABSTRACT FROM AUTHOR]

The article focuses on the creation of the virtual patient (VP) cases for primary care-based learning. It mentions that opportunities were given to students who engage to VP cases in terms of refining and practicing their unique clinical reasoning skills. It states that VP cases was created by identifying key core curriculum then students observe consultations. It says that a learning resource was created for undergraduate primary care education through the VP case design.

The aim of the study is to devise a new reliable dynamic route guidance approach by integrating the A* algorithm, the concept of reliability and an existing route guidance method into a single package. A new purpose-developed software tool, the Imperial College Navigation Software (ICNavS), is presented, so as to implement and demonstrate the new approach on a real road network, using simulated data. A summary of the background of the program is given, followed by a procedure developed in order to model the features of real road networks as well as missing data. Then, a simulation experiment on a part of West London's road network is carried out and the results are presented. [ABSTRACT FROM AUTHOR]

Objectives To assess the first commercially available virtual reality (VR) simulator to incorporate procedural modules for training of inexperienced gynaecological surgeons to perform laparoscopic salpingectomy for ectopic pregnancy. Design Prospective cohort study. Setting Departments of surgery and gynaecology in central London teaching hospitals. Sample Thirty gynaecological surgeons were recruited to the study, and were divided into novice (<10 laparoscopic procedures), intermediate (20–50) and experienced (>100) groups. Methods All subjects were orientated to the VR simulator with a basic skills task, followed by performing ten repetitions of the virtual ectopic pregnancy module, in a distributed manner. Main outcome measures Operative performance was assessed by the time taken to perform surgery, blood loss and total instrument path length. Results There were significant differences between the groups at the second repetition of the ectopic module for time taken (median 551.1 versus 401.2 versus 249.2 seconds, P= 0.001), total blood loss (median 304.2 versus 187.4 versus 123.3 ml, P= 0.031) and total instrument path length (median 17.8 versus 8.3 versus 6.8 m, P= 0.023). The learning curves of the experienced operators plateaued at the second session, although greater numbers of sessions were necessary for intermediate (seven) and novice (nine) surgeons to achieve similar levels of skill. Conclusions Gynaecological surgeons with minimal laparoscopic experience can improve their skills during short-phase training on a VR procedural module. In contrast, experienced operators showed nonsignificant improvements. Thus, VR simulation may be useful for the early part of the learning curve for surgeons who wish to learn to perform laparoscopic salpingectomy for ectopic pregnancy. [ABSTRACT FROM AUTHOR]

This work investigates differences in lateral displacement when driving on curved and straight road sections in real-road and simulator conditions. We observed 100 licensed drivers on a rural road and 100 in a fixed-base simulator. Speed and lateral position on the real road were measured using videocameras. The analysis indicates that the mean vehicle lateral displacement is in general higher on the real road than in the simulator. However, these differences decrease for higher speeds at curved sections and for lower speeds at straight sections. It was also found that the standard deviation of the vehicle lateral displacement is significantly lower on the real road than the corresponding values in the simulator, at either curved or straight sections. Actual or potential applications of this research are related to a more realistic assessment of driving behavior scenarios derived on the basis of simulation experiment results. [ABSTRACT FROM AUTHOR]

The article offers information on executable biology, a biological modelling approach developed by Jasmin Fisher of Microsoft Research in Cambridge, England. It states that the approach was used by Fisher and her colleagues to make a discovery in molecular biology. She says that the program could make cell simulations and their components, making it more easier for researchers to build, understand, and verify experimentally. She adds that each set of biological knowledge pictured on the screen corresponds to a programming statement on the first screen.

The article presents information on a technique developed by researchers from England to examine small peptides on the surface of a gold nanoparticle. It is noted that the new method could lead to new ways of designing and manufacturing materials on the tiniest scale. The initiative is financed by the Biotechnology and Biological Sciences Research Council (BBSRC) of Great Britain. A chemistry-based approach and computer modeling were used by the scientists to determine the distance between the peptides where they sit assembled on the gold nanoparticle.

Introduction: Peer observation of teaching is important in the development of educators. The foundation curriculum specifies teaching competencies that must be attained. We created a developmental model of peer observation of teaching to help our foundation doctors achieve these competencies and develop as educators. Methods: A process for peer observation was created based on key features of faculty development. The project consisted of a pre-observation meeting, the observation, a post-observation debrief, writing of reflective reports and group feedback sessions. The project was evaluated by completion of questionnaires and focus groups held with both foundation doctors and the students they taught to achieve triangulation. Results: Twenty-one foundation doctors took part. All completed reflective reports on their teaching. Participants described the process as useful in their development as educators, citing specific examples of changes to their teaching practice. Medical students rated the sessions as better or much better quality as their usual teaching. Discussion: The study highlights the benefits of the project to individual foundation doctors, undergraduate medical students and faculty. It acknowledges potential anxieties involved in having teaching observed. Conclusion: A structured programme of observation of teaching can deliver specific teaching competencies required by foundation doctors and provides additional benefits. [ABSTRACT FROM AUTHOR]