G Traustason Editor

C. M. Campbell is an Honorary Reader in the School of Mathematics and Statistics at the University of St Andrews. M. R. Quick is a Senior Lecturer in the School of Mathematics and Statistics at the University of St Andrews. E. F. Robertson is Professor Emeritus in the School of Mathematics and Statistics at the University of St Andrews. C. M. Roney-Dougal is a Senior Lecturer in the School of Mathematics and Statistics at the University of St Andrews. G. C. Smith is a Senior Lecturer in the Department of Mathematical Sciences at the University of Bath. G. Traustason is a Reader in the Department of Mathematical Sciences at the University of Bath.