PubMed HealthSearch

Biomedical subjects

S McKee

Publications and source records attributed to S McKee.

4 recordsLinked to original sources

Modelling coccidial infection in chickens: emphasis on vaccination by in-feed delivery of oocysts.

Trickle immunization of poultry by incorporating wildtype strains of coccidia in the feed has been shown to be an effective and practical means of controlling coccidiosis. Here we develop a mathematical model of the life cycle of Eimeria tenella and estimate the model parameters from extant experimental studies. Numerical solutions of the model compare well with experiment. The model provides quantitative estimates of the required trickle immunization hitherto only available after extensive time-consuming trials.

Animal Feed

The effects of equine rhinovirus, influenza virus and herpesvirus infection on tracheal clearance rate in horses.

The response of horses exposed to three common respiratory viruses was studied by measuring tracheal mucociliary clearance rates in the trachea. Tracheal clearance rates (TCR) were determined before, during illness and following recovery in horses exposed to equine rhinovirus (ERhV-2), equine influenza virus (EIV) and equine herpesvirus (EHV-4) by means of lateral scintigraphs made following an injection of technetium-99m sulphide colloid into the tracheal lumen. In six horses exposed to ERhV-2, TCR remained within normal limits. Exposure to EIV resulted in reduced TCR in six of seven horses, with TCR remaining below the 95% confidence limits of normal values for each horse for up to 32 days despite the resolution of clinical signs. Moderate changes were observed in six horses exposed to EHV-4, but significant reductions in TCR were evident in three animals. Measurement of TCR was a useful, minimally-invasive technique which demonstrated that respiratory viruses may cause persistent changes in TCR, even though clinical signs are not evident.

Animals

GESA--a two-dimensional processing system using knowledge base techniques.

The successful analysis of two-dimensional (2-D) polyacrylamide electrophoresis gels demands considerable experience and understanding of the protein system under investigation as well as knowledge of the separation technique itself. The present work concerns the development of a computer system for analysing 2-D electrophoretic separations which incorporates concepts derived from artificial intelligence research such that non-experts can use the technique as a diagnostic or identification tool. Automatic analysis of 2-D gel separations has proved to be extremely difficult using statistical methods. Non-reproducibility of gel separations is also difficult to overcome using automatic systems. However, the human eye is extremely good at recognising patterns in images, and human intervention in semi-automatic computer systems can reduce the computational complexities of fully automatic systems. Moreover, the expertise and understanding of an "expert" is invaluable in reducing system complexity if it can be encapsulated satisfactorily in an expert system. The combination of user-intervention in the computer system together with the encapsulation of expert knowledge characterises the present system. The domain within which the system has been developed is that of wheat grain storage proteins (gliadins) which exhibit polymorphism to such an extent that cultivars can be uniquely identified by their gliadin patterns. The system can be adapted to other domains where a range of polymorpic protein sub-units exist. In its generalised form, the system can also be used for comparing more complex 2-D gel electrophoretic separations.

Algorithms