On Memorial Day,the day Americans remember the fallen, the president or vice president traditionally lays a wreath at the Tomb of the Unknown - this is the scene from last year.

VOA: standard.2010.05.26

"We also looked at the part of the brain called the hippocampus which is very important for forming the sort of memories we make everyday,you know, when you have to remember a pin number or you have to remember how to get somewhere, and the hippocampus, if it's a good size that means you are less likely to develop Alzheimer's,"

VOA: standard.2009.12.30