PI
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Look up PI in Wiktionary, the free dictionary. |
PI may refer to:
Science
- Isoelectric point, the pH at which a particular molecule or surface carries no net electrical charge.
- Parental investment, in evolutionary biology
- Paternity Index, a value used to calculate probability of paternity
- Phosphatidylinositol, a class of lipids
- Pistillata, a gene that influences the development of flowers in the ABC model of flower development
- Plasticity index, a measure of the plasticity of a soil
- Polyimide, a polymer of imide monomers
- Ponderal index, a measure of leanness of a person (similar to body mass index)
- Principal investigator, the lead scientist or engineer for a particular project
- Propidium iodide, a chemical used as a DNA stain
- Protease inhibitor (pharmacology), class of drugs used to treat or prevent infection by viruses, including HIV and Hepatitis C
- Protease inhibitor (biology), molecules that inhibit the function of proteases
- Pulsatility index, a ratio of blood flow rates
Companies and organizations
- Perimeter Institute for Theoretical Physics, a research centre in Ontario, Canada
- Privacy International, a UK-based charity that supports the right to privacy across the world
- Defunct Piedmont Airlines (1948–89) IATA airline code
Political parties
- Partido Independiente or Independent Party, a political party in Uruguay
- Partido Intransigente or Intransigent Party, an Argentine political party
- Partit per la Independència, a political party in Catalonia (Spain) of the 1990s
Professional occupations
- Principal investigator, the lead scientist in a project
- Private investigator, a person who can be hired to undertake investigations
Computing
- Persistent identifier, a long-lasting reference to a digital object
- Processing Instruction, an SGML and XML node type
- Programmed instruction, a technology invented to improve teaching
Other uses
- PI controller, a concept in automation and control engineering
- Pass interference, a foul in American and Canadian gridiron football
- People's Initiative, one of the modes in which the constitution of the Philippines could be amended
- Politically Incorrect (blog), a German political blog
- Seattle Post-Intelligencer or P-I, a newspaper in the United States
- Primitive Instinct, an English rock band formed in 1987
- Profitability index, the ratio of payoff to investment of a proposed project
- Pirot's license plate code
- Pro forma Invoice