Echinococcal disease and the provision of humanitarian surgical aid in Bosnia

The Canadian Armed Forced have been deployed to the republics of the former Yugoslavia since 1992 as part of the United Nations Protection Force and the NATO-led Implementation Force. Most of the combat arms units have been supported by small, self-contained surgical teams for essential surgery. Considerable benefit is gained by cooperating with civilian surgeons. The experience of treating five patients with complicated hydatid disease endemic to the area is examined. Treatment of these patients requires performing major surgical procedures under austere conditions and must be undertaken with care. Careful selection and communication with the surgical nursing team and civilian surgeons is essential. Well selected cases can also pay tremendous dividends in terms of maintaining the skills of personnel who must be prepared for any emergency in addition to providing vital surgical assistance to these patients.     

The use of capsaicin in herpes zoster ophthalmicus neuralgia

The final stage in the production of a radiotherapy treatment plan must always be an independent check that the linear accelerator settings given on the plan do in fact deliver the required dose distribution. A tool is described that enables rapid checking of diaphragm settings in relation to the patient.     

Situated Innovation of e-Social Science: Integrating Infrastructure, Collaboration, and Knowledge in Developing e-Social Science

This article explores the relationships between academic knowledge and the practice of research in the construction of new computer-supported research tools for e-social science. The article draws on a U.K. e-social science pilot demonstrator project, "Collaborative Analysis of Offenders' Personal and Area-based Social Exclusion," that explores the relative impact of individual and neighborhood effects on geographical crime patterns. Three main dimensions of e-social science are addressed by the project: (1) identification of new social research foci, (2) adapting research processes, and (3) developing Grid-related research tools. The integration of these dimensions shows that research-driven and user-led development of computer-mediated research using the Grid can produce relevant and innovative tools for the social sciences.     

Flash photolysis of the carbon monoxide compounds of wild-type and mutant variants of cytochrome bo from Escherichia coli

The carbon monoxide compounds of the fully reduced and mixed valence forms of cytochrome bo from Escherichia coli were laser photolysed under anaerobic conditions at room temperature. The carbon monoxide recombined with characteristic rate constants of 50 s-1 or 35 s-1 in the fully reduced and mixed valence forms, respectively. Rates of CO recombination with the fully reduced enzyme were examined in a variety of mutant forms of cytochrome bo, produced by site-directed mutagenesis. A method was developed to deconvolute cytochromes bo and bd, leading to some reassessment of histidine ligands to the metals. Significant changes in the rate constant of recombination of carbon monoxide occurred in many of these mutants and these results could be rationalised generally in terms of our current working model of the folding structure of subunit I. In the mixed valence form of the enzyme the transient photolysis spectra in the visible region are consistent with a rapid electron redistribution from the binuclear centre to the low-spin haem. This electron transfer is biphasic, with rate constants of around 10(5) and 8000 s-1. The process was also examined in the His-333-Leu mutant, in which a putative histidine ligand to CuB is replaced by leucine, and which results in the loss of the CuB. It appeared that rapid haem-haem electron transfer could still occur. The observation that CuB is apparently not required for rapid haem-haem electron transfer is consistent with the recently proposed model in which the two haems are positioned on opposite sides of transmembrane helix X in subunit I of the oxidase.     

The UK Renewable Energy programme

The UK Government has supported a programme on Renewable Energy since 1975. In 1988 progress was reviewed and this led to some redirection of the programme with greater emphasis on the commercial development of renewables, as published in Energy Paper 55.The climate in which Renewable Energy operates has been influenced recently by a number of factors including privatisation of the UK electricity supply industry, when the Government introduced the New Fossil Fuel Obligation and publication of the Government's 1990 White Paper on the Environment which noted that the Government is working towards a figure of new renewable energy generating capacity of 1000 MW by 2000.The paper aims to give an overview of the present state of development of the renewable technologies in the UK and to discuss some of the factors - technical and non-technical - which will affect their likely future development.     

Reflection and transmission of plane waves at an interface between two fluids

The propagation, reflection, and transmission of a plane wave through a column of two fluids with a material discontinuity is studied by three methods: a mixed finite element formulation with both pressure and velocity at a point taken as independent variables, and a scaled and an un-scaled acoustic pressure formulation in which only the pressure at a point is taken as an independent variable. It is found that when mass densities of two fluids are close to each other, the un-scaled acoustic pressure formulation gives reasonable results. However, when the speeds of sound in two fluids are close to each other but their mass densities are quite different, and for cases where the first fluid has high impedance relative to that of the second fluid, a mixed or scaled pressure formulation is necessary. Without the mixed or scaled pressure formulation, the continuity conditions at the interface between two fluids are not well satisfied for the un-scaled pressure formulation. The consideration of viscosity of the two fluids and using a dispersion correction method in the time integration scheme in the mixed formulation slightly improves results.     

Discrete quadratic curvature energies

We present a family of discrete isometric bending models (IBMs) for triangulated surfaces in 3-space. These models are derived from an axiomatic treatment of discrete Laplace operators, using these operators to obtain linear models for discrete mean curvature from which bending energies are assembled. Under the assumption of isometric surface deformations we show that these energies are quadratic in surface positions. The corresponding linear energy gradients and constant energy Hessians constitute an efficient model for computing bending forces and their derivatives, enabling fast time-integration of cloth dynamics with a two- to three-fold net speedup over existing nonlinear methods, and near-interactive rates for Willmore smoothing of large meshes.