Heroes and Villains

Portia Walker: optimism in Yemen has been punctured by a devastating bomb blast in the capital. Alan Johnston: a state funeral has taken place in Sicily to honour a man who dared to take on the Mafia - and paid the ultimate price. Laura Trevelyan: the town in Mexico which has grown rich on the profits of sex trafficking. Matthew Teller: how the authorities in the Saudi capital Riyadh have transformed a public rubbish tip into lush parkland complete with lakes and walkways. and Bethany Bell: why the people of Vienna, who live in one of the world's most desirable capital cities, still seem to have plenty to moan about.