Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is the ribose derivative deoxyribose, the polymer is DNA. Nucleic acids are naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells and make up the genetic material. Nucleic acids are found in abundance in all living things, where they create, encode, and then store information of every living cell of every life-form on Earth. In turn, they function to transmit and express that information inside and outside the cell nucleus to the interior operations of the cell and ultimately to the next generation of each living organism. The encoded information is contained and conveyed via the nucleic acid sequence, which provides the 'ladder-step' ordering of nucleotides within the molecules of RNA and DNA. They play an especially important role in directing...

A supercluster is a large group of smaller galaxy clusters or galaxy groups; they are among the largest known structures in the universe. The Milky Way is part of the Local Group galaxy group (which contains more than 54 galaxies), which in turn is part of the Virgo Supercluster, which is part of the Laniakea Supercluster. The large size and low density of superclusters means that they, unlike clusters, expand with the Hubble expansion. The number of superclusters in the observable universe is estimated to be 10 million. Existence The existence of superclusters indicates that the galaxies in the Universe are not uniformly distributed; most of them are drawn together in groups and clusters, with groups containing up to some dozens of galaxies and clusters up to several thousand galaxies. Those groups and clusters and additional isolated galaxies in turn form even larger structures called superclusters. Their existence was first postulated by George Abell in his 1958 Abell catalogue of galaxy clusters. He called them "second-order clusters", or clusters of clusters.Superclusters form massive structures of galaxies...

The Parthenon (; Ancient Greek: Παρθενών, Parthenṓn, [par.tʰe.nɔ̌ːn]; Greek: Παρθενώνας, Parthenónas, [parθeˈnonas]) is a former temple on the Athenian Acropolis, Greece, that was dedicated to the goddess Athena during the fifth century BC. Its decorative sculptures are considered some of the high points of Greek art, an enduring symbol of Ancient Greece, democracy and Western civilization.The Parthenon was built in thanksgiving for the Hellenic victory over Persian invaders during the Greco-Persian Wars. Like most Greek temples, the Parthenon also served as the city treasury....

Caesium (IUPAC spelling) (or cesium in American English) is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of 28.5 °C (83.3 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. It is pyrophoric and reacts with water even at −116 °C (−177 °F). It is the least electronegative element, with a value of 0.79 on the Pauling scale. It has only one stable isotope, caesium-133. Caesium is mined mostly from pollucite. The element has 40 known isotopes, making it, along with barium and mercury, one of the elements with the most isotopes. Caesium-137, a fission product, is extracted from waste produced by nuclear reactors. The German chemist Robert Bunsen and physicist Gustav Kirchhoff discovered caesium in 1860 by the newly developed method of flame spectroscopy. The first small-scale applications for caesium were as a "getter" in vacuum tubes and in photoelectric cells. In 1967, acting on Einstein's proof that the speed of...

Square rig is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular, or square, to the keel of the vessel and to the masts. These spars are called yards and their tips, outside the lifts, are called the yardarms. A ship mainly rigged so is called a square-rigger. History The oldest archaeological evidence of use of a square-rig on a vessel is an image on a clay disk from Mesopotamia from 5000 BC. Single sail square rigs were used by the ancient Egyptians, the Phoenicians, the Greeks, the Romans, and the Celts. Later the Scandinavians, the Germanic peoples, and the Slavs adopted the single square-rigged sail, with it becoming one of the defining characteristics of the classic “Viking” ships. See also Glossary of nautical terms (A-L) Glossary of nautical terms (M-Z) References...

Integrated Water Resource Management: An Interdisciplinary Approach [PDF] [2u76gjldb3k0]. This book addresses the enormous global challenge of providing balanced and sustainable solutions to urgent water proble...

In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold. Spacetime diagrams can be used to visualize relativistic effects, such as why different observers perceive differently where and when events occur. Until the 20th century, it was assumed that the three-dimensional geometry of the universe (its spatial expression in terms of coordinates...

Karl Paul Reinhold Niebuhr (June 21, 1892 – June 1, 1971) was an American Reformed theologian, ethicist, commentator on politics and public affairs, and professor at Union Theological Seminary for more than 30 years. Niebuhr was one of America's leading public intellectuals for several decades of the 20th century and received the Presidential Medal of Freedom in 1964. A public theologian, he wrote and spoke frequently about the intersection of religion, politics, and public policy, with his most influential books including Moral Man and Immoral Society and The Nature and Destiny of Man. The latter is ranked number 18 of the top 100 non-fiction books of the twentieth century by Modern Library. Andrew Bacevich labelled Niebuhr's book The Irony of American History "the most important book ever written on U.S. foreign policy." The historian Arthur Schlesinger Jr. described Niebuhr as "the most influential American theologian of the 20th century" and Time posthumously called Niebuhr "the greatest Protestant theologian in America since Jonathan Edwards."Starting as a minister with working-class sympathies in the 1920s...

USAP, Usap, or usap may refer to: USA Perpignan, a rugby union club in Perpignan, France USA Pickleball, the national governing body for pickleball in the United States. Unacknowledged Special Access Program United States Antarctic Program United States Student Achievers Program United States Academic Pentathlon University of San Pedro Sula, Honduras