North Florida/South Georgia Veterans Health System, Gainesville, Florida, USA.

Disciple of Anatomy and Regenerative Medicine Institute, School of Medicine, College of Medicine, Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland.

A J Stone

Department of Medical Physics and Clinical Engineering, St. Vincent's University Hospital, Dublin, Ireland.

S Campisi

Department of Cardiovascular Surgery, University Hospital of Saint-Etienne, Saint-Etienne, France.

C Kerskens

Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.

Mines Saint-Etienne, Université Jean Monnet Saint-Etienne, INSERM, Saint-Etienne, France.