We instinctively lower our heads and pitch them forward when we know ourselves to be in the presence of someone we consider our superior.

FORBES: Getting Inside V. S. Ramachandran's Head

The imaging agent can't be used to diagnose someone with Alzheimer's disease if the individual doesn't experience memory impairment because the presence of amyloid in the brain doesn't alone suggest that someone has Alzheimer's.

WSJ: FDA Approves Alzheimer's Test Developed by Eli Lilly

Dr Ritchie said he has no experience of seeing someone confined to one place for this length of time but he told the jury it is possible that someone in this situation would have pressure sores which could be worsened by the presence of urine.

BBC: Lynda Spence trial: Alleged injuries would be 'painful'

In domestic or bar-room disputes, the presence of a gun makes it far more likely that someone will die.

ECONOMIST: South Africa

In the European Parliament today, the tell-tale sign is the presence of a cute cuddly seal toy, sitting on someone's desk, or peeking winsomely out of their bag.

ECONOMIST: European politics