Atelopus petersi Atelopus petersi Atelopus petersi is a species of toads in the family Bufonidae. It is endemic to Ecuador and is known from the Cordillera Oriental in the Napo Province and more provisionally, in the Chimborazo Province. The specific name "petersi" honors James A. Peters, an American zoologist who collected the first specimens of this species in 1962 and provided a description under the name "Atelopus pachydermus". Common names Peters' stubfoot toad and Peters' jambato toad have been coined for it. Adult males measure and adult females in snout–vent length. The snout is acuminate. The tympanic membrane, annulus, and stapes are
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