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Invariant theory is a branch of abstract algebra dealing with actions of groups on algebraic varieties, such as vector spaces, from the point of view of their effect on functions. Classically, the theory dealt with the question of explicit description of polynomial functions that do not change (are …

An individual is one that exists as a distinct entity. Individuality (or self-hood) is the state or quality of living as an individual; particularly (in the case of humans) as a person unique from other people and possessing one's own needs or goals, rights and responsibilities. The concept of an in…

Laeta Kalogridis (/ˈliːtə ˌkæləˈɡriːdɪs/ LEE-tə KAL-ə-GREE-diss) is an American screenwriter and television and film producer. She has written scripts for Alexander (2004), Night Watch (2004), Pathfinder (2007) and Shutter Island (2010). She also served as an executive producer for the television se…

Air pollution is the presence of substances in the air that are harmful to humans, other living beings or the environment. Pollutants can be gases, like ozone or nitrogen oxides, or small particles like soot and dust. Both outdoor and indoor air can be polluted.…

Number theory is a branch of pure mathematics devoted primarily to the study of the integers and arithmetic functions. Number theorists study prime numbers as well as the properties of mathematical objects constructed from integers (for example, rational numbers), or defined as generalizations of th…

Bolesław Konstanty "Bill" Gebert (22 July 1895 – 13 February 1986) was a leading official in the Communist Party of America, remembered as one of the organization's top Polish-language leaders. He was a Soviet agent during World War II and was an official of the Polish People's Republic after the wa…

The flag consists of the red cross of Saint George (the patron saint of England), edged in white, superimposed on the red saltire of Saint Patrick (the patron saint of Ireland), also edged in white, superimposed on the saltire of Saint Andrew (the patron saint of Scotland). Wales is not represented …

Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromosome from the father. Sex differentiation of the male fetus is governed by the SRY gene on the Y chromosome. During puberty, hormones which stimulate androgen production result in the developm…

General semantics is a school of thought that incorporates philosophic and scientific aspects. Although it does not stand on its own as a separate school of philosophy, a separate science, or an academic discipline, it describes itself as a scientifically empirical approach to cognition and problem …

A landmass, or land mass, is a large region or area of land that is in one piece and not noticeably broken up by oceans. The term is often used to refer to lands surrounded by an ocean or sea, such as a continent or a large island. In the field of geology, a landmass is a defined section of continen…