Have not seen this presentation posted previously. If it has been, I apologize for duplicating.
This presentation covers everything known about NAD/Sirtuin interaction with further elucidation of mTorc1 activity in stem cells during calorie restriction are longevity inducing. Rapamycin cancels this behavior. Guarente also comments on prospective research areas related to Alzheimer's.
I think it's a pretty good watch, no matter your level of background on this subject matter.