Brian Thomas graduated from University of College of Wales, Aberystwyth where he also obtained his doctorate in plant physiology. Following post-doctoral study in Canada and the UK, he worked as a research scientist at the Glasshouse Crops Research Institute which later became Horticulture Research International. In 1995 he moved to HRI Wellesbourne where he is Head of the Molecular and Environmental Physiology Department. He is currently a Vice President of the Association Internationale de Photobiologie.Daphne Vince-Prue graduated from the University of London (Wye College) and did postgraduate work in plant physiology at UC Berkeley. She obtained her doctorates at the Universities of Reading and London, and subsequently taught plant physiology to students of horticulture and botany at Reading for most of her career. She has also been a Scientific Adviser and later Head of the Physiology and Chemistry Division at the Glasshouse Crops Research Institute for the Agricultural Research Council. Since her retirement in 1986 she has maintained contacts with research groups working in photoperiodism, and continues her interest in horticulture as a committee member of the Royal Horticultural Society.