A Review of Methods for the Analysis of the Expected Value of Information

Over recent years Value of Information analysis has become more widespread in health-economic evaluations, specifically as a tool to perform Probabilistic Sensitivity Analysis. This is largely due to methodological advancements allowing for the fast computation of a typical summary known as the Expected Value of Partial Perfect Information (EVPPI). A recent review discussed some estimations method for calculating the EVPPI but as the research has been active over the intervening years this review does not discuss some key estimation methods. Therefore, this paper presents a comprehensive review of these new methods. We begin by providing the technical details of these computation methods. We then present a case study in order to compare the estimation performance of these new methods. We conclude that the most recent development based on non-parametric regression offers the best method for calculating the EVPPI efficiently. This means that the EVPPI can now be used practically in health economic evaluations, especially as all the methods are developed in parallel with

House of Flags, Parliament Square, London

The House of Flags was a temporary freestanding structure erected on Parliament Square for the 2012 Summer Olympic and Paralympic Games. It was one of the Mayor of London’s ‘Wonder Series’ of installations to celebrate the capital’s design talent by showcasing cutting edge architectural projects throughout London. It was made of plywood panels containing cut out symbols, each printed with the flag of a nation participating in the games. Together the flag panels created a large timber jigsaw, a matrix of symbols, shimmering colours, shadows and perforations, inviting the public to experience an image of the cosmopolitan world as well as an image of multi-ethnic London. The structure was designed to be demounted and installed elsewhere. The installation responded to the following research questions: How can the unifying spirit of the Olympic and Paralympic Games and the cosmopolitanism of London be reflected in a temporary installation? How can the design objectives of an interlocking, stacked structure be reconciled with the protocols of heraldry? How can a temporary installation be prefabricated for hand assembly, demounting and reassembly? Once the initial decision to design an interlocking, stacked structure had been made, the architects worked closely with manufacturers and printers to research the production of the CNC cut printed plywood panels. Panels were designed to be lighter towards the top of the structure to facilitate hand assembly. The architects worked closely with the Flag Institute, the world’s leading research and documentation centre for flag information, to determine how flag designs and relationships could correspond with their strict protocols. The structure was a highly visible installation and popular photographic backdrop throughout the Olympic and Paralympic games and was widely disseminated in the media as a symbol of the games. This output will also be returned by Yeoryia Manolopoulou for University College London

A Bayesian partial identification approach to inferring the prevalence of accounting misconduct

This paper describes the use of flexible Bayesian regression models for estimating a partially identified probability function. Our approach permits efficient sensitivity analysis concerning the posterior impact of priors on the partially identified component of the regression model. The new methodology is illustrated on an important problem where only partially observed data is available - inferring the prevalence of accounting misconduct among publicly traded U.S. businesses

Procesiones en la Constantinopla bizantina: la evidencia del manuscrito Dresden A104

This paper discusses supplicatory liturgical processions (litae) and their routes in eleventh-century Constantinople by examining a hitherto neglected source; the eleventh-century Praxapostolos Dresden A104. References to supplicatory processions found in this source are examined in comparison with one of the most important sources on Byzantine ceremonial: the tenth-century kanonarion-synaxarion known as the Typikon of the Great Church. By comparing the evidence relating to the use of sites within the city during commemorations that included a procession in these two sources it is possible to draw some conclusions in terms of the way the litanic landscape changed between the tenth and eleventh centuries. The paper aims to present new evidence relating to the way annually commemorative processions were performed in Byzantine Constantinople.Este artículo discute las procesiones suplicatorias litúrgicas (litae) y las rutas procesionales en la Constantinopla del siglo XI mediante el examen de una fuente hasta ahora descuidada: el Praxapostolos Dresden A104 del siglo XI. Las referencias a las procesiones suplicatorias que proporciona esta fuente, se discute en comparación con una de las fuentes más importantes del ceremonial bizantino: el kanonarion-synaxarion del siglo X conocido con el nombre de Typikon de la Gran Iglesia. Al comparar la evidencia relativa al uso de los lugares urbanos durante las conmemoraciones que incluían una procesión en estas dos fuentes, es posible extraer algunas conclusiones en cuanto a la forma en que cambió el paisaje litánico entre los siglos X y XI. El artículo pretende presentar nuevas pruebas relativas al modo en que se realizaban las procesiones conmemorativas anuales en la Constantinopla bizantina

Performing the architectural plan: egocentric and allocentric drawing

Elaborating on experiments in spatial cognition and representation from the Losing Myself project, this chapter highlights the confines of the architectural plan as a drawing medium that privileges an allocentric conception of space, one that is progressively lost to those living with dementia. The chapter describes an alternative, performative mode of drawing that animates the architectural plan and incorporates egocentric representation, a more direct, person-centered conception of space that is retained for longer as we age. Architects had not considered the egocentric and allocentric functions of spatial reference that occur in the human brain before. Allocentric spatial referencing requires a sophisticated form of mental manipulation whereby the world is understood by assessing and imagining multiple spatial relationships between objects and is dependent on the ability to retain a mental image of the whole. In egocentric spatial referencing, the brain makes simpler connections, however only between the viewer’s position and the observed objects. Studies of aging show a greater preservation of egocentric functions in the brain and a marked decline in the more complex allocentric processes, alongside a weakening of the ability to switch between the two. A loss of allocentric abilities is common to all forms of Alzheimer’s disease. In Losing Myself, a collaborative investigation of dementia and architecture, Yeoryia Manolopoulou and Niall McLaughlin developed a kind of performance drawing that synthesizes both allocentric and egocentric representation. This novel drawing method fosters a deeper understanding of how architecture is experienced, and how we might approach its design. ‘Performing’ the architectural plan simultaneously creates temporal and empathetic connections between the space of building as experienced in time by different occupants and the space of drawing produced by multiple authors

Endocrine Hypertension, Adrenal Steroids and Development of a Saliva Based Aldosterone Assay as a Potential Screening Method

Recent evidence has shown the increased incidence of PA in approximately 15% of the hypertensive population, making a non-invasive and simple screening method for the measurement of aldosterone levels necessary. The use of saliva for determination of steroid hormones is now widely used and accepted and salivary aldosterone concentrations have previously been reported at around 30% of those seen in plasma. Furthermore, there is a current lack of longitudinal and systematic studies addressing the involvement of aldosterone in the regulation of the RAAS in rodents due to sample volume restrictions and the lack of sensitivity to detect the very low aldosterone concentrations in commercially available assays. We developed a non-isotopic, competitive immunoassay for the determination of aldosterone levels in saliva, as well as in human and mouse plasma samples. The assay employs an aldosterone-biotin conjugate as the tracer and end-point determination through time-resolved fluorescence (TR-FIA) with Streptavidin-Europium as the detectable label. No pretreatment or purification of saliva is necessary while a simple extraction step is incorporated for the assessment of plasma levels. A polyclonal antibody was used for the development of the saliva assay giving a lower limit of detection of 19 pg/ml for each 50µl sample. Similarly, a highly specific monoclonal antibody against aldosterone, exhibiting a more sensitive linear working range starting from 8 pg/ml is used to detect aldosterone in 50µl of plasma. The monoclonal antibody could potentially also be used for the determination of salivary aldosterone levels, however this was not sufficiently evaluated in the studies shown here and further investigation of the exact assay conditions is needed. Inter- and intra-assay coefficients of variation, mean recoveries, accuracy and linearity were validated for both assays and the assay results correlated significantly with a commercially available radioimmunoassay for plasma in both settings. Overall, salivary aldosterone was found to correspond to approximately 28% of the concentrations seen in plasma and reflected the changes seen with posture and ACTH stimulation accurately. The assay presents the additional possibility of using salivary aldosterone levels, in combination with salivary cortisol, as a diagnostic tool in a clinical setting to screen suspected cases of PA and exclude healthy subjects. The salivary aldosterone to cortisol ratio remains elevated in PA persons due to autonomous hypersecretion of aldosterone throughout the day, alongside decreasing levels of cortisol, and can be clearly distinguished from healthy persons above a cut-off level of 0.1. Furthermore, as aldosterone concentrations are acutely affected by ACTH it was determined that sampling for this test should be carried out in the evening to avoid stress factors as well as diurnal fluctuations. In addition, as basal aldosterone values and those after suppression and stimulation under different conditions were found within the linear range of the assay, it is proposed that the assay could be especially useful to monitor adrenocortical function in pharmacological and dietary intervention studies in rodent models where repeated sampling and volumes collected are limited and measurement of multiple blood parameters is desirable