Unlike some patients, Lana's extra heartbeats tended to occur during exertion - but doctors struggled to trigger the palpitations and therefore pinpoint the exact area of the problem until they used the electrode vest.

BBC: Electrode vest gives hope to heart rhythm patients

It was felt along the length of Sumatra but, unlike the one on December 26th, did not trigger a great wave and so devastated only a relatively small area: the islands of Nias and Simeulue and neighbouring islets about 130km (80 miles) off the coast.

ECONOMIST: Another earthquake, but no wave, strikes Sumatra

Moreover, the opening of a halfway decent grocery store is often the trigger for the arrival of other better-class shops in the area, which then spurs a local economic revival.

ECONOMIST: Poor access to fresh food is a solvable health problem

They have already won a small victory: an American-financed army unit set up last year to clear coca farmers' roadblocks in the Chapare (formerly the main growing area) is being disbanded, after several mistakes by trigger-happy troops.

ECONOMIST: Politics in Bolivia: Progress or collapse | The

The stated intention was to trigger a plankton bloom in the hope of attracting salmon to this food source and enhance fisheries in the area.

UNESCO: MEDIA SERVICES

Police teams were dressed in snow gear Friday, holding the trigger guards on their assault-style rifles while scouring eight square miles near Big Bear Lake, a popular skiing area two hours east of Los Angeles.

CNN: February 9, 2013 -- Updated 1735 GMT (0135 HKT)