THAI AND MUNICIPAL authorities mounted a successful campaign years ago to control air pollution involving PM10 – particulate matter 10 microns in diameter or more. The problem since then – one that’s steadily worsening and more difficult to curb – is PM2.5.

Rafael Nadal described long-time rival Novak Djokovic as "one of the more complex" players he's ever met as they prepare to clash for the 52nd time on Friday with a Wimbledon final spot at stake.