Keele University

About: Keele University is a education organization based out in Newcastle-under-Lyme, United Kingdom. It is known for research contribution in the topics: Population & Stars. The organization has 11318 authors who have published 26323 publications receiving 894671 citations. The organization is also known as: Keele University.

Prevalence of radiographic osteoarthritis—it all depends on your point of view

Abstract: Objectives Knee pain and disability in older people may occur in the apparent absence of radiographic osteoarthritis. However, the view chosen to define radiographic osteoarthritis may be critical. We have investigated the prevalence and compartmental distribution of radiographic osteoarthritis in people with knee pain using different combinations of three separate radiographic views. Methods We performed a population-based study of 819 adults aged 50 yr and over with knee pain (part of the Clinical Assessment Study - Knee [CAS(K)]). Three radiographic views were obtained: weight-bearing posteroanterior (PA) semiflexed/metatarsophalangeal view; supine skyline; and supine lateral. Results Complete data for all three views were available on 777 subjects. The distribution of compartmental radiographic osteoarthritis was 314 (40%) combined tibiofemoral/patellofemoral, 186 (24%) isolated patellofemoral, 31 (4%) isolated tibiofemoral and 246 (32%) normal. Hence, the overall prevalence of radiographic osteoarthritis was 531/777 (68.3%) in this symptomatic population. Using a PA view alone (reflecting tibiofemoral osteoarthritis only) would identify 56.7% of the 531, whilst the addition of a skyline or lateral view increased this to 87.0%. When using both skyline and lateral views in addition to the PA view, 98.7% cases of radiographic osteoarthritis were identified. In addition to prevalence, compartmental distribution altered markedly when different combinations of views were used. Conclusions Multiple views detect more radiographic osteoarthritis than single views alone. When different combinations of views are used, the prevalence and compartmental distribution of osteoarthritis changes and this may alter the accepted relationship, or lack of it, between symptoms and radiographic change.

A fast hybrid algorithm for exoplanetary transit searches

Abstract: We present a fast and efficient hybrid algorithm for selecting exoplanetary candidates from wide-field transit surveys. Our method is based on the widely used SysRem and Box Least-Squares (BLS) algorithms. Patterns of systematic error that are common to all stars on the frame are mapped and eliminated using the SysRem algorithm. The remaining systematic errors caused by spatially localized flat-fielding and other errors are quantified using a boxcar-smoothing method. We show that the dimensions of the search-parameter space can be reduced greatly by carrying out an initial BLS search on a coarse grid of reduced dimensions, followed by Newton-Raphson refinement of the transit parameters in the vicinity of the most significant solutions. We illustrate the method's operation by applying it to data from one field of the SuperWASP survey, comprising 2300 observations of 7840 stars brighter than V = 13.0. We identify 11 likely transit candidates. We reject stars that exhibit significant ellipsoidal variations caused indicative of a stellar-mass companion. We use colours and proper motions from the Two Micron All Sky Survey and USNO-B1.0 surveys to estimate the stellar parameters and the companion radius. We find that two stars showing unambiguous transit signals pass all these tests, and so qualify for detailed high-resolution spectroscopic follow-up.

Microwave Tomography for Brain Imaging: Feasibility Assessment for Stroke Detection

Abstract: There is a need for a medical imaging technology, that supplements current clinical brain imaging techniques, for the near-patient and mobile assessment of cerebral vascular disease. Microwave tomography (MWT) is a novel imaging modality that has this potential. The aim of the study was to assess the feasibility, and potential performance characteristics, of MWT for brain imaging with particular focus on stroke detection. The study was conducted using MWT computer simulations and 2D head model with stroke. A nonlinear Newton reconstruction approach was used. The MWT imaging of deep brain tissues presents a significant challenge, as the brain is an object of interest that is located inside a high dielectric contrast shield, comprising the skull and CSF. However, high performance, nonlinear MWT inversion methods produced biologically meaningful images of the brain including images of stroke. It is suggested that multifrequency MWT has the potential to significantly improve imaging results.