Rhinella lindae Rhinella lindae Rhinella lindae is a species of toad in the family Bufonidae. It is endemic to Colombia and known from its type locality, Murri in the municipality of Frontino, and from , both on the western slope of the Cordillera Occidental, Antioquia Department. The specific name "lindae" honors , an American herpetologist. However, common name Murri beaked toad has been coined for this species. The holotype, an adult female, measures , whereas the paratype male—of unknown maturity status—measures in snout–vent length. The snout is long and acuminate. In the female, tympanic annulus is present but the tympanic membrane is
Dirac membrane Dirac membrane A model of a charged membrane introduced by Paul Dirac in 1962. Dirac's original motivation was to explain the mass of the muon as an excitation of the ground state corresponding to an electron. Anticipating the birth of string theory by almost a decade, he was the first to introduce what is now called a type of Nambu–Goto action for membranes. In the Dirac membrane model the repulsive electromagnetic forces on the membrane are balanced by the contracting ones coming from the positive tension. In the case of the spherical membrane, classical equations of motion imply that the