Disease the time between infection and the appearance of symptoms. The latency period is the time between infection and the ability of the disease to spread to another person, which may precede, follow, or be simultaneous with the appearance of symptoms. Some viruses also exhibit a dormant phase, called viral latency, in which the virus hides in the body in an inactive state. For example, varicella zoster virus causes chickenpox in the acute phase; after recovery from chickenpox, the virus may remain dormant in nerve cells for many years, and later cause herpes zoster (shingles). Diseases may be classified by cause,
Center for Scientific and Technical Creativity of the Youth Center for Scientific and Technical Creativity of the Youth Centers for Scientific and Technical Creativity of the Youth , NTTM) were established in the late Soviet Union during "perestroika" as enterprises whose goal was commercialization of science and technology. Other translations of the Russian term are Scientific and Technical Creativity of Youth Center, Youth Center for Scientific Creativity, etc. The Centers were introduced by a joint decree of the USSR Council of Ministers, All-Union Central Council of Trade Unions, and Komsomol Central Committee no. 321 (March 13, 1987) "об образовании единой общегосударственной системы научно-технического творчества молодежи". They were established as