Written medical discharge communication from an acute stroke service: a project to improve content through development of a structured stroke-specific template

Specific guidelines for the content of discharge summaries from acute stroke services do not currently exist. The aims of this project were to assess the strengths and weaknesses of stroke discharge communication from Imperial College Healthcare NHS Trust, to develop a structured template to guide completion, and to re-audit discharge communication following its implementation. The audit compared local performance against record standards from the Academy of Medical Royal Colleges (1), which was augmented by criteria generated from the British Association of Stroke Physicians (BASP) Stroke Service Standards (2). Discharge information was examined within the Trust’s Electronic Discharge Communication (EDC) system to determine the recording of selected items for consecutively discharged patients from the hyperacute and acute stroke units. The audit was repeated following implementation of a newly developed stroke-specific discharge summary template. Fifty-one EDC summaries were examined at baseline (July 2012) and 30 summaries at re-audit (January 2013). The criteria which showed low adherence initially and which showed the most significant improvement following the introduction of the template were the guidance on blood pressure and lipids targets (increased from 2% and 0% respectively at baseline, to 93% post intervention), and the driving and flying advice (from 3% to 79%). Documentation was also seen to improve for measures of physical and cognitive function, discharge arrangements, and follow up plans. This audit cycle has demonstrated improvement in the consistency of content within written discharge communication following the introduction of a structured stroke-specific template adhering to combined criteria from identified standards

Regge calculus from a new angle

In Regge calculus space time is usually approximated by a triangulation with flat simplices. We present a formulation using simplices with constant sectional curvature adjusted to the presence of a cosmological constant. As we will show such a formulation allows to replace the length variables by 3d or 4d dihedral angles as basic variables. Moreover we will introduce a first order formulation, which in contrast to using flat simplices, does not require any constraints. These considerations could be useful for the construction of quantum gravity models with a cosmological constant.Comment: 8 page

Robust artificial neural networks and outlier detection. Technical report

Large outliers break down linear and nonlinear regression models. Robust regression methods allow one to filter out the outliers when building a model. By replacing the traditional least squares criterion with the least trimmed squares criterion, in which half of data is treated as potential outliers, one can fit accurate regression models to strongly contaminated data. High-breakdown methods have become very well established in linear regression, but have started being applied for non-linear regression only recently. In this work, we examine the problem of fitting artificial neural networks to contaminated data using least trimmed squares criterion. We introduce a penalized least trimmed squares criterion which prevents unnecessary removal of valid data. Training of ANNs leads to a challenging non-smooth global optimization problem. We compare the efficiency of several derivative-free optimization methods in solving it, and show that our approach identifies the outliers correctly when ANNs are used for nonlinear regression

Finiteness and Dual Variables for Lorentzian Spin Foam Models

We describe here some new results concerning the Lorentzian Barrett-Crane model, a well-known spin foam formulation of quantum gravity. Generalizing an existing finiteness result, we provide a concise proof of finiteness of the partition function associated to all non-degenerate triangulations of 4-manifolds and for a class of degenerate triangulations not previously shown. This is accomplished by a suitable re-factoring and re-ordering of integration, through which a large set of variables can be eliminated. The resulting formulation can be interpreted as a ``dual variables'' model that uses hyperboloid variables associated to spin foam edges in place of representation variables associated to faces. We outline how this method may also be useful for numerical computations, which have so far proven to be very challenging for Lorentzian spin foam models.Comment: 15 pages, 1 figur