IN a review in NATURE 1 it is stated that the equation of conduction of heat can be regarded only as a limiting case of an equation arising in the calculus of variations. A successful attempt has been ...

Every year, nearly 200,000 Americans turn to surgeons for help with their obesity, seeking bariatric surgery to lose weight and prevent life-threatening health problems. But after more than two ...

Rare species are frequently genetically depauperate compared with widespread species, but the degree to which low genetic variation affects short-term viability is still unresolved. We examined the ...

(1) We investigate problems associated with the measurement and interpretation of population density variability that have confounded most, if not all, previous studies of the subject. (2) The most ...