Batchelor described Pistorius as someone who "had a trip switch, " quick to get angry and fight.

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While most researchers agree that light exposure and melatonin can help reduce the symptoms of jet lag after arriving at your destination, not everyone thinks it makes sense to switch sleep schedules before a trip, which can cut into social time with family and friends.

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When one machine gun became inoperable he directed the return to the rally point to switch to another gun truck for a third trip into the ambush area, where his accurate fire directly supported the remaining U.S. personnel and Afghan soldiers fighting their way out of the ambush.

WHITEHOUSE: The White House