Prices have soared: the cost of cerium oxide (often used as a catalyst) has increased sixfold since the start of the year, and is 20 times higher than in 2005.

ECONOMIST: Rare earths and China

Warped Physique is a solid removal spell, but it can be used as the clutch catalyst for getting those crucial extra points in to win a match.

FORBES: Exclusive Dragon's Maze Preview: Warped Physique

Kadra used this disappointment as a catalyst to set up a Somali women's team in west London, changing attitudes about women's football and bringing women in the local community together.

BBC: David Beckham's 2018 World Cup bid letter of support

The UNESCO-Microsoft Task Force on Higher Education and Information and Communication Technology (ICT) will create a strategic plan of action to identify how ICT can be used by governments as a catalyst for change.

UNESCO: EDUCATION