Acetylcholine is an organic chemical that functions in the brain and body of many types of animals, including humans, as a neurotransmitterâa chemical released by nerve cells to send signals to other cells. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic. Substances that interfere with acetylcholine activity are called anticholinergics. Acetylcholine is the ...
Every interior algebra can be represented as a topological field of sets with its interior and closure operators corresponding to those of the topological space. Given a topological space the clopen sets trivially form a topological field of sets as each clopen set is its own interior and closure.
Abstract algebra is the set of advanced topics of algebra that deal with abstract algebraic structures rather than the usual number systems. The most important of these structures are groups, rings, and fields. Important branches of abstract algebra are commutative algebra, representation theory, and homological algebra. Linear algebra, elementary number theory, and discrete mathematics are sometimes considered branches of abstract algebra.