Answer: Living heart donors do occur but only rarely, perhaps a few per year at most, says University of Michigan, Ann Arbor, transplantation surgeon Dr. Jeffrey Punch. To understand it, take two patients: Joe has bad lungs but the surgeons would prefer to transplant him with a heart and lungs together. To do this, Joe's heart and lungs have to be removed, and they are replaced with the heart and lungs from a recently deceased donor.

Joe's lungs are, of course, no good to anyone — that's why he needed a transplant — so they are discarded. Joe's heart, however, is fine and can be given to someone with a bad heart. Bill has a bad heart and needs a heart transplant. When Joe's heart and lungs are removed, his heart can then be transplanted into Bill, whose own heart can then be removed and discarded.

Recap: That's two living patients, one deceased organ donor, and skillful surgeons versed in this medical legerdemain known as "domino transplant." Amazing!

Question: What's some pain relief you must really believe in?

Answer: Researchers have begun exploring what might be termed "faith-based analgesia," where striking a religious state of mind in devout Catholics triggered brain processes associated with substantial relief from physical pain, says Bruce Bower in "Science News" magazine.

While viewing classic religious images, the Catholics who were subjected to uncomfortable hand shocks reported feeling less pain than did atheists or agnostics under similar circumstances. Functional MRI (brain imaging) showed a change in the brain activity of these volunteers only while they looked at the religious icons.

"What's exciting is that this new study shows a neural mechanism by which religious belief affects pain perception," says Duke University psychiatrist Harold Koenig. Relief was accompanied by vigorous activity in a part of the brain associated with emotional detachment and control over pain, much as for placebo treatments.

Question: In an unfamiliar restaurant, could an understanding of economics help you decide which menu items to order?

Answer: Despite the daunting plenitude of choices, you need not feel completely lost, says Tyler Cowen in "Discover Your Inner Economist." At a fancy restaurant ($50 and up for a dinner), ask yourself: "Which item am I least likely to want to order? Which sounds least appetizing?" Then order that item.