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McGraw Hill Financial, Inc. is an American publicly traded corporation headquartered in Rockefeller Center in New York City. Its primary areas of business are financial, publishing, and business services.
A functionally heterogenous class of genes, ranging from nuclear transcription factors to cell adhesion molecules having as their common denominator that their function must be compromised during development and progression of a given tumor. The most important and most widely studied tumor suppressor is called p53. Its importance becomes evident from the fact that mutations in its gene are found in approximately 50% of all human cancers, thus constituting the most frequent alteration in a single human cancer-associated gene. The prevalence of p53 mutations in human cancer has spurred research worldwide to decipher p53 functions. It is now clear that the major function of p53 is to preserve the integrity of the genome of a cell under various conditions of cellular stress, endowing p53 with the title “guardian of the genome,” coined by David Lane, one of the discoverers of p53 in 1979.
Industry:Science
A fundamental aspect of social organization that is established by fighting or display behavior and results in a ranking of the animals in a group. Social, or dominance, hierarchies are observed in many different animals, including insects, crustaceans, mammals, and birds. In many species, size, age, or sex determines dominance rank. Dominance hierarchies often determine first or best access to food, social interactions, or mating within animal groups.
Industry:Science
A fundamental geological unit used in the description and interpretation of layered sediments, sedimentary rocks, and extrusive igneous rocks. A formation is defined on the basis of lithic characteristics and position within a stratigraphic succession. It is usually tabular or sheetlike, and is mappable at the Earth's surface or traceable in the subsurface (for example, between boreholes or in mines). Examples are readily recognized in the walls of the Grand Canyon of northern Arizona (see <b>illus.</b>). Each formation is referred to a section or locality where it is well developed (a type section), and assigned an appropriate geographic name combined with the word formation or a descriptive lithic term such as limestone, sandstone, or shale (for example, Temple Butte Formation, Hermit Shale). This usage of “formation” by geologists differs from its informal lay usage for stalactites, stalagmites, and other mineral buildups in caves.
Industry:Science
A fundamental goal of physics is to describe and understand all the forces appearing in nature. All the phenomena occurring in the universe can be traced to the action of just four fundamental forces or interactions, namely, the gravitational, electromagnetic, strong, and weak interactions. This classification, although it greatly simplifies the picture of different interactions, does not provide real understanding of the nature of the different forces. Recent theoretical work suggests the existence of an M-theory, which would unify and explain all the interactions in a natural way.
Industry:Science
A fundamental hypothesis according to which classical mechanics can be understood as a limiting case of quantum mechanics; or conversely, many characteristic features in quantum mechanics can be approximated on the basis of classical mechanics, provided classical mechanics is properly reinterpreted. This idea was first proposed by N. Bohr in the early 1920s as a set of rules for understanding the spectra of simple atoms and molecules.
Industry:Science
A fundamental ingredient in quantum field theories, which dictates that all interactions in nature, all the force laws, are unchanged (invariant) on being subjected to the combined operations of particle-antiparticle interchange (so-called charge conjugation, <i>C</i>), reflection of the coordinate system through the origin (parity, <i>P</i>), and reversal of time, <i>T.</i> The operations may be performed in any order; <i>TCP</i>, <i>TPC</i>, and so forth, are entirely equivalent. If an interaction is not invariant under any one of the operations, its effect must be compensated by the other two, either singly or combined, in order to satisfy the requirements of the theorem.
Industry:Science
A fundamental tenet of quantum mechanics is that every particle also has a wave nature and every wave also has a particle nature, at least in principle. For light, which in classical physics is an electromagnetic wave, the particle nature was first postulated by Albert Einstein in 1905, after Max Planck's introduction of the quantum of action in 1900. The particles of light are now called photons and have found abundant experimental confirmation.
Industry:Science
A furnace is an apparatus in which heat is liberated and transferred directly or indirectly to a solid or fluid mass for the purpose of effecting a physical or chemical change. The source of heat is the energy released in the oxidation of fossil fuel (commonly known as combustion) or the flow of electric current through adjacent semiconductors or through the mass to be heated. In recent years, scientific and engineering effort has been made to utilize nuclear and solar energy for heating purposes. Therefore, according to the source of heat and method of its application, there are four categories of furnaces; combustion, electric, nuclear, and solar, in the order of their present commercial or industrial importance.
Industry:Science
A fuzzy set is a generalized set to which objects can belong with various degrees (grades) of memberships over the interval (0,1). In general, fuzziness describes objects or processes that are not amenable to precise definition or precise measurement. Thus, fuzzy processes can be defined as processes that are vaguely defined and have some cognitive uncertainty in their description. The data arising from fuzzy systems are, in general, soft, with no precise boundaries. Examples of such systems are large-scale engineering complex systems, social systems, economic systems, management systems, medical diagnostic processes, and human perception.
Industry:Science
A galaxy that is observed to be undergoing an unusually high rate of formation of stars. It is often defined as a galaxy that, if it continues to form stars at the currently observed rate, will exhaust its entire supply of star-forming material, the interstellar gas and dust, in a time period that is very short compared to the age of the universe. For a typical starburst galaxy, this gas and dust exhaustion time scale is less than 10<sup>8</sup> years, that is, less than 1% of the age of the universe. Since such a galaxy must shortly run out of star-forming material, the high star formation rate currently observed not only must end soon but also must have started relatively recently or the gas supply would have run out long ago. It follows that such galaxies must be undergoing a passing burst of star formation. The rates of star formation that are estimated to occur in starbursts can exceed 100 times the mass of the Sun per year for the most energetic bursts observed in the nearby universe. This may be compared to about 2–3 solar masses per year in the Milky Way Galaxy. However, there are large uncertainties in such estimates because there is only weak evidence on the range of masses of stars that form in starburst events. There are theoretical limits to the total rate of star formation that can occur in a starburst. One limit is derived from the mass of all the available interstellar material turning into stars during the time taken for that material to fall inward under gravity to form a typically sized galaxy. Another limit is related to the expectation that when large numbers of newly formed massive stars reach supernova stage, they will blow away much of the remaining star-forming material, thus inhibiting the burst.
Industry:Science
