A power law distribution in patients' lengths of stay in hospital

The distribution of patients' lengths of stay in English hospitals is measured by using routinely collected data from 11 years. It is found to be well approximated by a power law distribution spanning over more than 3 decades. To explain this observation, a theoretical resource allocation model is presented. It is based on iterative long-term scheduling of hospital beds, and its main assumption is that future beds are allocated preferentially. This represents a situation where di®erent parts of the health care system compete for resources, with bargaining powers proportional to current resource levels

Eigenvalue distribution of large dilute random matrices

We study the eigenvalue distribution of dilute N3N random matrices HN that in the pure ~undiluted! case describe the Hopfield model. We prove that for the fixed dilution parameter a the normalized counting function ~NCF! of HN converges as N!` to a unique sa(l). We find the moments of this distribution explicitly, analyze the 1/a correction, and study the asymptotic properties of sa(l) for large ulu. We prove that sa(l) converges as a !` to the Wigner semicircle distribution ~SCD!. We show that the SCD is the limit of the NCF of other ensembles of dilute random matrices. This could be regarded as evidence of stability of the SCD to dilution, or more generally, to random modulations of large random matrices

Mediapolis: an introduction

The organisation of this workshop has been prompted by concerns with the way media so often seem to get left out of writing on cities and urban politics (rather than vice-versa). We agree with Iveson’s (2007) argument that urban and media studies have much more in the way of shared concerns when it comes to politics than is conventionally thought to be the case. As a result, we are hoping this workshop will create an occasion for urban scholars to meet those studying media, to explore what difference it makes to explicitly consider the place of media practices in making a politics of cities, and conversely, to consider what is left out when such practices are relegated to the background. In certain ways, we are suggesting a contemporary return to something like Robert Park’s inclination in relation to cities and media. In his seminal essay on the natural history of the newspaper, for example (Park, 1925), Park exhibits a style which does not generally seem to distinguish between or oppose the urban and the media when studying politics and democracy. This surely has something to do with Park’s own intellectual period, and the absence of established disciplines in media or urban studies. Yet this is also precisely the point of the workshop: an opportunity for engagement and discussion through a similar sort of pre-disciplinary spirit

High-pressure/high-temperature synthesis of transition metal oxide perovskites

Perovskite and related Ruddlesden-Popper type transition metal oxides synthesised at high pressures and temperatures during the last decade are reviewed. More than 60 such new materials have been reported since 1995. Important developments have included perovskites with complex cation orderings on A and B sites, multiferroic bismuth-based perovskites, and new manganites showing colossal magnetoresistance (CMR) and charge ordering properties

Proposed reference models for nitrous oxide and methane in the middle atmosphere

Data from the Stratospheric and Mesospheric Sounder (SAMS) on the Nimbus 7 satellite, for the period from Jan. 1979 - Dec. 1981, are used to prepare a reference model for the long-lived trace gases, methane and nitrous oxide, in the stratosphere. The model is presented in tabular form on seventeen pressure surfaces from 20 to 0.1 mb, in 10 degree latitude bins from 50S to 70N, and for each month of the year. The means by which the data quality and interannual variability, and some of the more interesting globally and seasonally variable features of the data are discussed briefly

A simple tool to predict admission at the time of triage

Aim To create and validate a simple clinical score to estimate the probability of admission at the time of triage. Methods This was a multicentre, retrospective, cross-sectional study of triage records for all unscheduled adult attendances in North Glasgow over 2 years. Clinical variables that had significant associations with admission on logistic regression were entered into a mixed-effects multiple logistic model. This provided weightings for the score, which was then simplified and tested on a separate validation group by receiving operator characteristic (ROC) analysis and goodness-of-fit tests. Results 215 231 presentations were used for model derivation and 107 615 for validation. Variables in the final model showing clinically and statistically significant associations with admission were: triage category, age, National Early Warning Score (NEWS), arrival by ambulance, referral source and admission within the last year. The resulting 6-variable score showed excellent admission/discharge discrimination (area under ROC curve 0.8774, 95% CI 0.8752 to 0.8796). Higher scores also predicted early returns for those who were discharged: the odds of subsequent admission within 28 days doubled for every 7-point increase (log odds=+0.0933 per point, p&#60;0.0001). Conclusions This simple, 6-variable score accurately estimates the probability of admission purely from triage information. Most patients could accurately be assigned to ‘admission likely’, ‘admission unlikely’, ‘admission very unlikely’ etc., by setting appropriate cut-offs. This could have uses in patient streaming, bed management and decision support. It also has the potential to control for demographics when comparing performance over time or between departments.</p

Luscher Term for k-string Potential from Holographic One Loop Corrections

We perform a systematic analysis of k-strings in the framework of the gauge/gravity correspondence. We discuss the Klebanov-Strassler supergravity background which is known to be dual to a confining supersymmetric gauge theory with chiral symmetry breaking. We obtain the k-string tension in agreement with expectations of field theory. Our main new result is the study of one-loop corrections on the string theoretic side. We explicitly find the frequency spectrum for both the bosons and the fermions for quadratic fluctuations about the classical supergravity solution. Further we use the massless modes to compute 1/L contributions to the one loop corrections to the k-string energy. This corresponds to the Luscher term contribution to the k-string potential on the gauge theoretic side of the correspondence.Comment: 39 pages, 3 figures. New Calculation showing explicit k -> M - k symmetry of Energy utilizing the new figure. Discussion of non-k-dependence of Luscher term at end of last section right before Conclusion. Same version to be published in JHE