Bangladesh, June 4 -- Jet lag is nature's reminder that while humans can fly around the world, they still leave their body clocks at home. It's taxing enough for most of us, but particularly so for military personnel - such as pilots and special forces - who may be deployed to distant locations on short notice.

DARPA, the Pentagon's pet research agency, thinks it has a solution: bioimplants that will not just fight fatigue and disorientation, but also fight bacteria that afflict soldiers with diarrhea.

Home remedies for jet lag abound, such as taking melatonin tablets or adjusting their sleep schedule before the flight. But none of them are practical for military use. "Current mechanisms for physically adapting circadian rhythms to new ...