Appraisal Framework for Integrated Transport

This working paper outlines an appraisal framework for the Integrated Transport project. The project examined the demand implications from the introduction of a Taktfahrplan timetable onto the east coast mainline rail route. The Taktfahrplan concept is frequently referred to as an interval timetable and is based on trains leaving stations at the same time past the hour throughout the operational day. A stated preference exercise was conducted to estimated what values people placed on such a timetable and these values were added to the more conventional elements of generalised cost to obtain the changes in demand that would result from the introduction of a Taktfahrplan. The working paper is divided into a number of sections that will highlight, • the key implications to arise from the Integrated Transport project; • the demand model; • the appraisal framework; • the data sources used within the appraisal framework; and • the results of the appraisal framework. Interested readers are also referred to the a conference paper that will be presented at the European Transport Conference in Strasbourg later this year (Wardman et al, 2003)

Acousto-optic tunable filters (AOTFs) optimised for operation in the 2-4μm region

Acousto-Optic Tunable Filters (AOTFs) are electronically-controlled bandpass optical filters. They are often preferred in applications in spectroscopy where their agility and rapid random-access tuning can be deployed to advantage. When used for spectral imaging a large aperture (typically 10mm or more) is desired in order to permit sufficient optical throughput. However, in the mid IR the λ2 dependence on RF drive power combined with the large aperture can prove to be a hurdle, often making them impractical for many applications beyond about 2μm. We describe and compare a series of specialised free-space configurations of AOTF made from single crystal tellurium dioxide, that require relatively low RF drive power. We report on AOTFs specifically optimised for operation with a new generation of Supercontinuum source operating in the 2-4μm window and show how these may be used in a spectral imaging system. Finally, we describe an AOTF with an (acoustic) Fabry-Perot cavity operating at acoustic resonance rather than the conventional travelling-wave mode; the acoustic power requirement therefore being reduced. We present an analysis of the predicted performance. In addition, we address the practical issues in deploying such a scheme and outline the design of a prototype "resonant AOTF" operating in the 1-2μm region

Thermodynamics of the spin-flop transition in a quantum XYZ chain

A special limit of an antiferromagnetic XYZ chain was recently shown to exhibit interesting bulk as well as surface spin-flop transitions at T=0. Here we provide a complete calculation of the thermodynamics of the bulk transition using a transfer-matrix-renormalization-group (TMRG) method that addresses directly the thermodynamic limit of quantum spin chains. We also shed some light on certain spinwave anomalies at low temperature predicted earlier by Johnson and Bonner.Comment: 4 pages, 6 Postscript figure

Direct and indirect orthotic management of medial compartment osteoarthritis of the knee

Osteoarthritis (OA) is a painful condition and affects approximately 80% of individuals by the age of 55 [1], with knee OA occurring two times more frequently than OA of the hand or hip [2].The condition is more prevalent in the medial compartment and restricts the daily lives of individuals due to pain and a lack of functional independence. Patients with medial compartment osteoarthritis often have a varus alignment, with the mechanical axis and load bearing passing through this compartment with a greater adduction moment leading to greater pain and progression of osteoarthritis [3]. Surgery for the condition is possible although in some cases, particularly younger patients or those not yet requiring surgery, clinical management remains a challenge. Before surgery is considered, however, conservative management is advocated, though no one treatment has been shown to be most effective, and there are few quality biomechanical or clinical studies. Of the conservative approaches the principal orthotic treatments are valgus knee braces and laterally wedged foot inlays. Studies of knee valgus bracing have consistently demonstrated an associated decreased pain and improved function [4], and greater confidence [5]. A laterally wedged foot inlay has a thicker lateral border and applies a valgus moment to the heel. It is theorised that by changing the position of the ankle and subtalar joints during weight-bearing [6] the lateral wedges may apply a valgus moment across the knee as well as the rearfoot, with the assumed reduction on load in the medial knee compartment [7]. However, there has been no study to directly compare these orthotic treatments in the same study. The aim of this research is to investigate the efficacy of valgus knee braces and laterally wedged foot inlays in reducing the varus knee moment

The Enhancon, Black Holes, and the Second Law

We revisit the physics of five-dimensional black holes constructed from D5- and D1-branes and momentum modes in type IIB string theory compactified on K3. Since these black holes incorporate D5-branes wrapped on K3, an enhancon locus appears in the spacetime geometry. With a `small' number of D1-branes, the entropy of a black hole is maximised by including precisely half as many D5-branes as there are D1-branes in the black hole. Any attempts to introduce more D5-branes, and so reduce the entropy, are thwarted by the appearance of the enhancon locus above the horizon, which then prevents their approach. The enhancon mechanism thereby acts to uphold the Second Law of Thermodynamics. This result generalises: For each type of bound state object which can be made of both types of brane, we show that a new type of enhancon exists at successively smaller radii in the geometry, again acting to prevent any reduction of the entropy just when needed. We briefly explore the appearance of the enhancon in the black hole interior.Comment: 22 pages, 2 figures, latex, epsfig (v2: Fixed trivial typos.

Supernovae and Positron Annihilation

Radioactive nuclei, especially those created in SN explosion, have long been suggested to be important contributors of galactic positrons. In this paper we describe the findings of three independent OSSE/SMM/TGRS studies of positron annihilation radiation, demonstrating that the three studies are largely in agreement as to the distribution of galactic annihilation radiation. We then assess the predicted yields and distributions of SN-synthesized radionuclei, determining that they are marginally compatible with the findings of the annihilation radiation studies.Comment: 7 pages, accepted for publication in New Astronomy Reviews (Astronomy with Radioactivites III

Research Report: A Preliminary Analysis of Medical Futility Decisionmaking: Law and Professional Attitudes

The debate in medical futility decisionmaking centers on the conflict between a patient insisting treatment and a doctor refusing to furnish it. Courts have taken two disparate approaches to the legal status of medical futility. Believing that such legal ambiguity may reflect ambiguity in the medical profession itself, this research report sought to identify any emerging consensus among professionals handling medical futility issues. The report explains the results of the Life Sustaining Treatment Survey, a nationwide survey of health care professionals at hospitals. Presented with a list of criteria, respondents assigned important ratings to the factors used in recent futility decisions at their institutions. The resulting data suggests that there is no consensus among professionals in medical futility decisionmaking. The data supports at least three distinct approaches for making futility decisions: emphasis on the patients’ preferences; providing for the patient and family; and adhering to objective medical and social norms. It is unlikely that the law will realize its full potential to regulate futility judgments until explicitly articulated professional standards emerge. This article advocates continued empirical research to document and test professional judgment principles. Such research may ultimately help identify factors that will form the basis for a consensus in medical futility decisionmaking

Trends in sexually transmitted infections in general practice 1990-2000: population based study using data from the UK general practice research database

Objective: To describe the contribution of primary care to the diagnosis and management of sexually transmitted infections in the United Kingdom, 1990-2000, in the context of increasing incidence of infections in genitourinary medicine clinics. Design: Population based study. Setting: UK primary care. Participants: Patients registered in the UK general practice research database. Main outcome measures: Incidence of diagnosed sexually transmitted infections in primary care and estimation of the proportion of major such infections diagnosed in primary care. Results: An estimated 23.0% of chlamydia cases in women but only 5.3% in men were diagnosed and treated in primary care during 1998-2000, along with 49.2% cases of non-specific urethritis and urethral discharge in men and 5.7% cases of gonorrhoea in women and 2.9% in men. Rates of diagnosis in primary care rose substantially in the late 1990s. Conclusions: A substantial and increasing number of sexually transmitted infections are diagnosed and treated in primary care in the United Kingdom, with sex ratios differing from those in genitourinary medicine clinics. Large numbers of men are treated in primary care for presumptive sexually transmitted infections