Roll function in a flight simulator

Method introduces roll into the flying-spot scanner by modifying the scanning waveforms

A study of the means of increasing the dynamic range of visual simulation by means of a flying-spot scanner Final report

Increasing dynamic range of visual simulation for pilots using flying spot scanne

Craniometaphyseal and craniodiaphyseal dysplasia, head and neck manifestations and management

Craniometaphyseal and craniodiaphyseal dysplasia are rare genetic disorders of bone due to modelling errors of long bones and skull bones. These syndromes present with multiple ENT symptomatology from an early age. The diagnostic distinction can now be made radiologically by serial skeletal survey which is important for prognosis. We review the clinical, radiological, computed tomography (CT) scan, otological, audiological and histopathological findings in two cases with craniodiaphyseal, and two cases with craniometaphyseal dysplasia, and report our experiences of medical and surgical treatment to date. In the craniodiaphyseal dysplasia, the hearing abnormality progressed from an initial conductive to a mixed loss on serial audiometric follow up. Temporal bone CT scans showed narrowing of the middle ear cavity, internal auditory meatus, and facial nerve canal at the geniculate ganglion. Benefits from choanal stenosis surgery, craniofacial remodelling and dacrocystorhinostomy were shortlived. Calcitriol therapy with a low calcium diet did not alter the clinical course of progression in our cases. The underlying defect, causing net bone formation in these phenotypically similar syndromes, appears to be different when based on the differing biochemical responses to calcitriol and bone biopsy findings. Increased numbers of osteoblasts were found in bone biopsies from both cases with craniodiaphyseal dysplasia. Early recognition is crucial in these conditions as therapy directed at the underlying bony defect has the best chance of success if initiated in infancy (Cole et al., 1988; Fanconi et al., 1988; Key et al., 1988)

Evaluation of the usefulness of a computer‐based learning program to support student learning in pharmacology

This study aims to evaluate the effectiveness of a computer‐based teaching program in supporting and enhancing traditional teaching methods. The program covers the pharmacology of inflammation and has been evaluated with a group of second‐year medical students at a UK university. The study assessed subject‐specific knowledge using a pre‐ and post‐test and surveyed, by questionnaire, students’ perceptions of the usefulness of the program to support learning before and after use. The use of computers for learning amongst this cohort of students was widespread. The results demonstrated an increase in students ‘ knowledge of the pharmacology of inflammation, coupled with a positive attitude towards the CBL program they had used and the advantages that this mode of study may provide in enabling students to manage their own learning. However, students did not feel that the program could substitute for traditional teaching (lectures)

The inefficiency of re-weighted sampling and the curse of system size in high order path integration

Computing averages over a target probability density by statistical re-weighting of a set of samples with a different distribution is a strategy which is commonly adopted in fields as diverse as atomistic simulation and finance. Here we present a very general analysis of the accuracy and efficiency of this approach, highlighting some of its weaknesses. We then give an example of how our results can be used, specifically to assess the feasibility of high-order path integral methods. We demonstrate that the most promising of these techniques -- which is based on re-weighted sampling -- is bound to fail as the size of the system is increased, because of the exponential growth of the statistical uncertainty in the re-weighted average

Differential and Twistor Geometry of the Quantum Hopf Fibration

We study a quantum version of the SU(2) Hopf fibration $S^7 \to S^4$ and its associated twistor geometry. Our quantum sphere $S^7_q$ arises as the unit sphere inside a q-deformed quaternion space $\mathbb{H}^2_q$. The resulting four-sphere $S^4_q$ is a quantum analogue of the quaternionic projective space $\mathbb{HP}^1$. The quantum fibration is endowed with compatible non-universal differential calculi. By investigating the quantum symmetries of the fibration, we obtain the geometry of the corresponding twistor space $\mathbb{CP}^3_q$ and use it to study a system of anti-self-duality equations on $S^4_q$, for which we find an `instanton' solution coming from the natural projection defining the tautological bundle over $S^4_q$.Comment: v2: 38 pages; completely rewritten. The crucial difference with respect to the first version is that in the present one the quantum four-sphere, the base space of the fibration, is NOT a quantum homogeneous space. This has important consequences and led to very drastic changes to the paper. To appear in CM

The 3D Spin Geometry of the Quantum Two-Sphere

We study a three-dimensional differential calculus on the standard Podles quantum two-sphere S^2_q, coming from the Woronowicz 4D+ differential calculus on the quantum group SU_q(2). We use a frame bundle approach to give an explicit description of the space of forms on S^2_q and its associated spin geometry in terms of a natural spectral triple over S^2_q. We equip this spectral triple with a real structure for which the commutant property and the first order condition are satisfied up to infinitesimals of arbitrary order.Comment: v2: 25 pages; minor change

The ‘Little Ice Age’ in the Southern Hemisphere in the context of the last 3000 years : Peat-based proxy-climate data from Tierra del Fuego

DM’s research (at Department of Earth Sciences, Uppsala University) was supported through a European Community Marie Curie Fellowship (Contract HPMF-CT-2000-01056).Peer reviewedPostprin

The ADHM Construction of Instantons on Noncommutative Spaces

We present an account of the ADHM construction of instantons on Euclidean space-time $\mathbb{R}^4$ from the point of view of noncommutative geometry. We recall the main ingredients of the classical construction in a coordinate algebra format, which we then deform using a cocycle twisting procedure to obtain a method for constructing families of instantons on noncommutative space-time, parameterised by solutions to an appropriate set of ADHM equations. We illustrate the noncommutative construction in two special cases: the Moyal-Groenewold plane $\mathbb{R}^4_\hbar$ and the Connes-Landi plane $\mathbb{R}^4_\theta$.Comment: Latex, 40 page