Familial Ménière's disease: clinical and genetic aspects

ABSTRACT Background and purpose:Mre's disease is not uncommon, with an incidence in Caucasians of about one in 2000. The incidence peaks in the fifth decade. Cases are usually isolated or sporadic, but in perhaps five per cent other family members are affected. We report here the clinical and genetic characteristics of a comprehensive set of familial Mre's disease cases from the UK.Methods:Forty-six affected families were studied. All cases were diagnosed using the American Academy of Otolaryngolog 8211;Head and Neck Surgery committee on hearing and equilibrium 1995, or more stringent, criteria.Outcomes and results:Autosomal dominant inheritance with reduced penetrance was the most likely mode of inheritance overall. Apparent genetic anticipation was observed, but may also be a result of ascertainment bias given the collection strategy. There was also a slight tendency for cases to result from maternal transmission within the families in this set. The family pedigrees are presented, and the authors have also set up a website at which all the pedigrees may be viewed in greater detai

Trace geochemistry of lunar material

The lunar samples from the Apollo 16 and 17 flights which were analyzed include soil, igneous rock, anorthositic gabbro, orange soil, subfloor basalt, and norite breccia. Up to 57 elements including majors, minors, rare earths and other trace elements were determined in the lunar samples. The analytical techniques used were spark source mass spectrometry and neutron activation analysis. The latter was done either instrumentally or with group radiochemical separations. The differences in abundances of the elements in lunar soils at the various sites are discussed. With regard to the major elements only Si is about the same at all the sites. A detailed analysis which was performed on a sample of the Allende meteorite is summarized

Comparing legislative mechanisms for SEA screening and decision-making: Austrian and Australian experiences

Austrian and Australian approaches to strategic environmental assessment (SEA) are compared with particular emphasis upon the legal basis for the initial phase of agreement/screening and the final stage of SEA decision-making and implementation. In Austrian SEA, screening is compulsory and the outcome leads only to recommendations, meaning that the SEA results have to be considered, but are not binding for the approval decision. In Australia engagement in SEA is largely voluntary but the process results in legally binding conditions of approval that can be applied to relevant actions arising from an assessed policy, plan or programme; the incentive for proponents to participate voluntarily is that subsequent project level activities may be exempt from further assessment processes. Compulsory SEA in Australia also provides a legally certain outcome, a factor of benefit to proponents. Examples of SEAs are provided to demonstrate the operation of the respective stages in the two countries. In Austria compulsory screening results in a lot of energy being spent avoiding triggering a full SEA. Although Australian proponents have been somewhat cautious in volunteering for SEA of their activities, there are signs that this is changing. We argue that the regulatory framework characteristics are a key determinant of the behaviour of proponents and the competent authority in practice and subsequently of SEA potential and outcomes. Consideration of the construct of the regulatory framework for SEA screening and decision-making provides a useful point of reflection for practitioners attempting to understand the effectiveness of SEA processes in a given jurisdiction

A hybrid layout algorithm for sub-quadratic multidimensional scaling

Many clustering and layout techniques have been used for structuring and visualising complex data. This paper is inspired by a number of such contemporary techniques and presents a novel hybrid approach based upon stochastic sampling, interpolation and spring models. We use Chalmers' 1996 O(N/sup 2/) spring model as a benchmark when evaluating our technique, comparing layout quality and run times using data sets of synthetic and real data. Our algorithm runs in O(N/spl radic/N) and executes significantly faster than Chalmers' 1996 algorithm, whilst producing superior layouts. In reducing complexity and run time, we allow the visualisation of data sets of previously infeasible size. Our results indicate that our method is a solid foundation for interactive and visual exploration of data

Metal speciation in urban runoff.

A literature review has identified free and weakly complexed dissolved as well as solid surface associated, metal species as those forms most likely to be bio available. To analyse bio available Zn, Cd, Pb and Cu fractions in urban runoff a speciation scheme was devised which provided a relatively rapid technique for separating the dissolved and suspended solid phases of storm water into appropriate fractions. A new method, termed Dialysis with Receiving Resins, which responds to bio available metal species by incorporating a specially developed cysteine resin, within a dialysis membrane, has been devised and tested, A small scale gullypot study allowed the identification of six major processes which affect metal mobilisation and transport. The relevance of these processes is discussed with reference to gullypot outflow loadings of the different metal fractions. Acid rain mobilisation was found to greatly increase the levels of bio available free and weakly complexed metal fractions. Mass balance studies showed that Zn, Cd and Cu have a residence time in the road surface/gullypot system of little more than one storm event whereas Pb tends to be more persistent due to its predominant association with the solid phase. The speciation scheme was also applied to the analysis of metal fractions in storm water outfall samples collected from urban catchments in Sweden and the U.K. Significant concentrations and loadings of metals were found for both catchments with, on average, bio available metal forms representing 68% of the Zn, 76% of the Cd, 66% of the Pb and 32% of the Cu. Individual metal species were found to load at different rates onto metal chemographs and can be explained in terms of controlling parameters, as well as the influence of mobilisation and transport processes. Cadmium and Cu concentrations in storm water were regularly found to exceed Water Quality Standards and also to accumulate to significant levels in the Dialysis with Receiving Resins method. These metals may therefore represent a direct threat to receiving water quality

Coordinating views for data visualisation and algorithmic profiling

A number of researchers have designed visualisation systems that consist of multiple components, through which data and interaction commands flow. Such multistage (hybrid) models can be used to reduce algorithmic complexity, and to open up intermediate stages of algorithms for inspection and steering. In this paper, we present work on aiding the developer and the user of such algorithms through the application of interactive visualisation techniques. We present a set of tools designed to profile the performance of other visualisation components, and provide further functionality for the exploration of high dimensional data sets. Case studies are provided, illustrating the application of the profiling modules to a number of data sets. Through this work we are exploring ways in which techniques traditionally used to prepare for visualisation runs, and to retrospectively analyse them, can find new uses within the context of a multi-component visualisation system

On Krein-like theorems for noncanonical Hamiltonian systems with continuous spectra: application to Vlasov-Poisson

The notions of spectral stability and the spectrum for the Vlasov-Poisson system linearized about homogeneous equilibria, f_0(v), are reviewed. Structural stability is reviewed and applied to perturbations of the linearized Vlasov operator through perturbations of f_0. We prove that for each f_0 there is an arbitrarily small delta f_0' in W^{1,1}(R) such that f_0+delta f_0$is unstable. When$f_0$ is perturbed by an area preserving rearrangement, f_0 will always be stable if the continuous spectrum is only of positive signature, where the signature of the continuous spectrum is defined as in previous work. If there is a signature change, then there is a rearrangement of f_0 that is unstable and arbitrarily close to f_0 with f_0' in W^{1,1}. This result is analogous to Krein's theorem for the continuous spectrum. We prove that if a discrete mode embedded in the continuous spectrum is surrounded by the opposite signature there is an infinitesimal perturbation in C^n norm that makes f_0 unstable. If f_0 is stable we prove that the signature of every discrete mode is the opposite of the continuum surrounding it.Comment: Submitted to the journal Transport Theory and Statistical Physics. 36 pages, 12 figure