Researchers holding the first long-term study of 'personalised' medicine found 15 per cent of very ill patients with various tumours treated after genetic tests survived three years.

While there have been many small-scale studies done, there has not yet been a large-scale or long-term study of brainwave entrainment.

However, one long-term study of elite trained athletes found that dilation of the left ventricle was only partially reversible after a long period of deconditioning.

One long-term study continues to survey the prevalence of disease in butterfly populations.

A long-term study in now being undertaken to catalogue changes and recovery after this event.