alertness
41Light pollution — This article is about light pollution in the visible spectrum. For information on pollution in the radio spectrum, see radio spectrum pollution. This time exposure photo of New York City at night shows skyglow, one form of light pollution …
42Recreational drug use — is the use of a drug, usually psychoactive, with the intention of creating or enhancing recreational experience. Such use is controversial, however, often being considered to be also drug abuse, and it is often illegal. Also, it may overlap with… …
43Nicotine — This article is about the chemical compound. For other uses, see Nicotine (disambiguation). Nicotine Systematic (IUPAC) name …
44Circadian rhythm — Circadian redirects here. For the album by the rock band 5th Projekt, see Circadian (album). Some features of the human circadian biological clock A circadian rhythm, popularly referred to as body clock, is an endogenously driven, roughly 24 hour …
45Biorhythm — A biorhythm (from Greek βιορυθμός biorhuthmos ) is a hypothetical cycle in physiological, emotional, or intellectual well being or prowess. Bio pertains to life and rhythm pertains to the flow with regular movement. Biorhythms theory has no more… …
46Tobacco smoking — Part of a series on Smoking …
47Speed limit — For a discussion of the maximum speed possible in the universe, see speed of light and special relativity. A road speed limit is the maximum speed allowed by law for road vehicles. Speed limits are commonly set and enforced by the legislative… …
48Animal testing — A white Wistar lab rat Description Around 50–100 million vertebrate animals are used in experiments annually. Subjects Animal testing, scien …
49Brain stem — Infobox Brain Name = Brain stem Latin = truncus encephali GraySubject = 187 Caption = Hind and mid brains; postero lateral view. IsPartOf = Brain Components = Medulla, Pons, Midbrain Artery = Vein = BrainInfoType = ancil BrainInfoNumber = 218… …
50Kalarippayattu — Kalaripayattu Country of origin India Parenthood Historic …
