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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 modestly diverse order constituting about 5500 species of medium-sized insects and representing about 9 extinct and 18 surviving families that currently occupy a broad range of terrestrial to freshwater habitats. They are distributed across all continents except Antarctica. Neuropterans are characterized by the holometabolous development of an egg→larva→pupa→adult sequence, whose greatest morphological and ecologic variability lies among their larvae. Neuropteran larvae include species such as underwater forms that feed on freshwater sponges (Sisyridae, spongillaflies), underground litter and root feeders (Ithonidae, ithonid lacewings), inhabitants of leaf surfaces that are pursuit predators of aphids (Chrysopidae, green lacewings), parasitoids and predators of spider and social wasp eggs (Mantispidae, mantisflies), and ambush predators that shallowly bury themselves at the bottoms of conical sand pits that snag infalling prey such as ants (Myrmeleontidae, antlions).
Industry:Science
A modification in the mathematical structure of a problem changing the problem from one that can be solved exactly, the unperturbed problem, to one, the perturbed problem, for which it is usually possible to obtain only an approximate solution. The methods employed for this purpose form perturbation theory. These methods attempt to express the solution of the perturbed problem in terms of the properties of the solutions of the unperturbed problem.
Industry:Science
A molecular device is an assemblage of a discrete number of molecular components (that is, a supramolecular structure) designed to achieve a specific function. Each molecular component performs a single act, while the entire supramolecular structure performs a more complex function, which results from the cooperation of the various molecular components. Molecular devices operate via electronic or nuclear rearrangements. Like any device, they need energy to operate and signals to communicate with the operator. The extension of the concept of a device, so common on a macromolecular level, to the molecular level is of interest not only for basic research but also for the growth of nanoscience and nanotechnology.
Industry:Science
A molecule exists in this electronic state when its total spin angular momentum quantum number <i>S</i> is equal to one. The triplet state is an important intermediate of organic chemistry. In addition to the wide range of triplet molecules available through photochemical excitation techniques, numerous molecules exist in stable triplet ground states, for example, oxygen molecules. Theoretical calculations, furthermore, make predictions concerning the spin multiplicities of the ground states of many prototype organic molecules such as cyclobutadiene, trimethylene methane, and methylene, and indicate that they will be triplets.
Industry:Science
A molecule possessing a permanent electric dipole moment. Molecules containing atoms of more than one element are polar except where forbidden by symmetry; molecules formed from atoms of a single element are nonpolar (except ozone). The dipole moments of polar molecules result in stronger intermolecular attraction, increased viscosities, higher melting and boiling points, and greater solubility in polar solvents than in nonpolar molecules.
Industry:Science
A molecule which contains an unpaired electron spin which can be detected with electron spin resonance (ESR) spectroscopy. Molecules are labeled when an atom or group of atoms which exhibit some unique physical property is chemically bonded to a molecule of interest. Groups containing unpaired electrons include organic free radicals and a variety of types of transition-metal complexes (such as vanadium, copper, iron, and manganese). Molecules with unpaired electron spins are readily detected with electron spin resonance spectroscopy. Through analysis of ESR spectra, rates of molecular motion whose motion is restrained by surrounding molecules can be determined. Measurement of rates of molecular motion and molecular orientation has proved to be very important in the study of a variety of types of biologically important problems.
Industry:Science
A molecule with an affinity to bind to a second atom or molecule. This affinity can be described in terms of noncovalent interactions, such as the type of binding that occurs in enzymes that are specific for certain substrates; or of a mode of binding where an atom or groups of atoms are covalently bound to a central atom, as in the case of coordination complexes and organometallic compounds. Ligands of the latter type can be further distinguished by the nature of the orbitals used in bond formation.
Industry:Science
A monoclinic sodic amphibole with composition close to Na<sub>2</sub>(Mg<sub>3</sub>Al<sub>2</sub>)Si<sub>8</sub>O<sub>22</sub>(OH)<sub>2</sub>. This mineral exhibits a characteristic blue color with distinct pleochroism from colorless to lavender blue when viewed in thin section by plane-polarized light. Outcrops of glaucophane-rich metamorphic rocks are commonly blue and tend to have good foliation; these rocks are termed blueschists.
Industry:Science
A monophyletic grade of craniates comprising Acanthodii, Actinopterygii (ray-finned fishes), and Sarcopterygii (coelacanths, lungfishes, and tetrapods). (Monophyletic refers to any form evolved from a single interbreeding population. Craniates are vertebrates distinguished by a cranium.) The Acanthodii (all fossil species) is the sister group to the actinopterygians and sarcopterygians, a relationship based on otoliths and certain details of the vertebral column and associated elements. The term Teleostomi, coined by C. L. Bonaparte in 1836, has changed in meaning, as have Acanthodii and Actinopterygii, which originated with E. D. Cope in 1871. The term Osteichthyes, first used by T. H. Huxley in 1880, is not used by J. S. Nelson in a formal taxonomic sense; however, the term is conveniently used for the vast number of fishes with a bony skeleton. The term Sarcopterygii was used by A. S. Romer to include the lobed-finned fishes, that is, crossopterygians and dipnoans; however, E. O. Wiley, and D. E. Rosen and collaborators include the tetrapods in Sarcopterygii to form a monophyletic group. The grade Teleostomi contains about 53,633 extant valid species, of which 26,891 are actinopterygians and 26,742 are sarcopterygians.
Industry:Science
A monospecific order of Asteroidea established for <i>Trichasteropsis wiessmanni</i>, the only Triassic asteroid known from articulated specimens. It is a small starfish with a relatively large disc and short arms. The skeleton is differentiated into marginals, actinals, and abactinals, the marginals comprising a single series of blocklike ossicles. The abactinal surface is composed of larger stellate plates and smaller rods and granules; a carinal row is present. Oral plates are large and well developed. Pedicellariae are not present. <i>Trichasteropsis</i> is the most primitive post-Paleozoic asteroid known and lies close to the latest common ancestor of all living asteroids. It comes from the Muschelkalk (Middle Triassic, Anisian-Ladinian) of Germany.
Industry:Science
