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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 class of marine arthropods, consisting of about 600 Recent and 3 Devonian species. The Pycnogonida, or Pantopoda, are commonly called sea spiders.
Industry:Science
A class of marine planktonic chromists. Their skeletons are composed of hollow, siliceous rods and (see <b>illus</b>.), resemble those of the Radiolaria, with which they have been grouped. They are usually subpyramidal or hemispherical in shape, delicately filigreed, and range in size from 10 to 150 micrometers. Two families and 11 genera of silicoflagellates have been described from siliceous sedimentary rocks ranging in age from the early Cretaceous to Recent, in association with abundant diatoms and siliceous sponge spicules, however, this may change pending systematic revision. One genus, <i>Dictyocha</i>, lives in the ocean today.
Industry:Science
A class of metamorphic rocks with one of the amphibole minerals as the dominant constituent. Most of the amphibolites are dark green to black crystalline rocks that occur as extensive layers widely distributed in mountain belts and deeply eroded shield areas of the continental crust. Amphibolite is the main country rock that has been intruded by the large granite masses found in most mountain ranges, with small and large masses of amphibolite present also as inclusions in granites.
Industry:Science
A class of microscopic, bilaterally symmetrical invertebrates which are generally less than 1 mm in length. About 400 species are known. Commonly called water bears, bear animalcules, or urslets, they are worldwide in distribution and are found in all habitats.
Industry:Science
A class of microsystems that combine the functions of optical, mechanical, and electronic components in a single, very small package or assembly. MOEMS devices can vary in size from several micrometers to several millimeters. MOEMS may be thought of as an extension of micro-electro-mechanical systems (MEMS) technology by the provision of some optical functionality. This optical functionality may be in the form of moving optical surfaces such as mirrors or gratings, the integration of guided-wave optics into the device, or the incorporation of optical emitters or detectors into the system. The term may be confused with micro-opto-mechanical systems (MOMS), which more properly refers to microsystems that do not include electronic functions at the microsystem location. MOEMS is a rapidly growing area of research and commercial development with great potential to impact daily life. The basic concept is the miniaturization of combined optical, mechanical, and electronic functions into an integrated assembly, or monolithically integrated substrate, through the use of micromachining processes derived from those used by the microelectronics industry. These processes, utilizing microlithography and various etch (subtractive) or deposition (additive) steps on a planar substrate, enable the production of extremely precise shapes, structures, and patterns in various materials.
Industry:Science
A class of phylum Arthropoda, subphylum Chelicerata. Merostomes are aquatic chelicerates, characterized by abdominal appendages bearing respiratory organs. Most merostomes are extinct; only the horseshoe crabs, comprising four species and three genera (<i>Carcinoscorpio</i> and <i>Tachypleus</i> of eastern Asia and <i>Limulus polyphemus</i> of eastern North America) survive. The body of a merostome consists of a prosoma, or head, which lacks antennae, has a pair of compound eyes and a pair of simple median eyes, and bears the chelicerae (pincers) and five pairs of uniramous walking legs with gnathobases for mastication. The opisthosoma, or trunk, consists of 12 or fewer segments which may be freely articulating or partly or entirely fused into a solid shield; the opisthosoma bears the respiratory appendages. The telson (tail) is a solid, usually spikelike, structure.
Industry:Science
A class of phylum Cnidaria (formerly known as Coelenterata) whose members are marine, live exclusively as polyps, and occur as solitary individuals or in clonal or colonial groups. Most adult anthozoans are attached to a firm object or the sea bottom but some burrow into soft sediments, and rare ones are planktonic. As is typical of cnidarians, sexual reproduction commonly gives rise to a planktonic larva, the planula, which metamorphoses to a polyp, usually when it settles onto the substratum.
Industry:Science
A class of plants, commonly called brown algae, in the chlorophyll <i>a</i>-<i>c</i> phyletic line (Chromophycota). Brown algae occur almost exclusively in marine or brackish water, where they are attached to rocks, wood, sea grasses, or other algae. Approximately 265 genera and 1500 species are recognized, arranged in about 15 orders.
Industry:Science
A class of plants, comprising the yellow-green algae, in the chlorophyll <i>a</i>–<i>c</i> phylectic line (Chromophycota). Alternate names are Tribophyceae, derived from <i>Tribonema</i>, a filamentous member of the class, and Heterokontae, referring to the presence of two kinds of flagella on each motile cell.
Industry:Science
A class of prokaryotic organisms coextensive with the division Cyanophycota of the kingdom Monera. Because these organisms have chlorophyll <i>a</i> and carry out oxygen-evolving photosynthesis, they have traditionally been aligned with algae and, with regard for their characteristic color, called blue-green algae. Microbiologists have emphasized the prokaryotic structure of these organisms and aligned them with bacteria, as the Cyanobacteria. Other names applied to these organisms include Cyanophyta at the level of division and Myxophyceae or Schizophyceae at the level of class. Blue-greens range in form from unicells 1–2 micrometers in diameter to filaments 10 cm (4 in.) long.
Industry:Science
