The Nobel Prize for Medicine has been awarded to three Americans for discoveries about the body's daily rhythms.
The laureates are Jeffrey Hall, Michael Rosbash and Michal Young.
Robash is on the faculty at Brandeis University, Young at Rockefeller University and Hall is at the University of Maine.
The citation for the 9 million kronor (R15 million) prize says the researchers isolated a gene that controls the normal daily biological rhythm. They "were able to peek inside our biological clock and elucidate its inner workings."
Circadian rhythms adapt one's physiology to different phases of the day, influencing sleep, behavior, hormone levels, body temperature and metabolism.
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