Based on computer modelling, the craft QinetiQ has developed thus far could complete a day-night cycle.

BBC: NEWS | Science/Nature | 'Eternal planes' to watch over us

Scientific research based on mathematical modelling indicates that restricting travel will be of limited or no benefit in stopping the spread of disease.

UNESCO: CONFINTEA VI

The study has been published in the journal Nephrology Dialysis Transplantation and its findings are drawn from NHS data and economic modelling based on clinical studies.

BBC: Kidney care 'needs to improve'

Modelling based on experience with previous plants suggests that the risk of a significant radiation leak from generation I reactors was between one in 1, 000 and one in 10, 000 per reactor year.

ECONOMIST: Safety