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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 group of small, deep-water cassiduloid echinoids with neotenous characteristics, treated as an order by some workers; possibly polyphyletic. The presence of bourrelets and phyllodes, the elongate first ambulacral plates, the undifferentiated tuberculation, and undifferentiated posterior interambulacral plating all indicate their relationships lie with cassiduloids. The only character shared by members of this group is the lack of petals (they have simple ambulacral pores only). Other characteristics, such as apical disc plating, are varied, indicating at least two independent origins from shallow-water cassiduloids.
Industry:Science
A group of species that utilize the same kinds of resources, such as food, nesting sites, or places to live, in a similar manner. Emphasis is on ecologically associated groups that are most likely to compete because of similarity in ecological niches, even though species can be taxonomically unrelated. The term was derived from the guild in human society composed of people engaged in an activity or trade held in common.
Industry:Science
A group of substances that are natural products of earth surface environments. Probably the most widely distributed organic carbon–containing materials in terrestrial and aquatic environments, they are dark-colored, predominantly aromatic, acidic, hydrophilic, molecularly flexible polyelectrolytes. Humic substances constitute 70–80% of the organic matter in inorganic soils and are formed from the chemical and biological degradation of plant and animal residues and from synthetic activities of microorganisms.
Industry:Science
A group of tiny marine crustaceans (body length 2.0–4.0 mm or 0.08–0.16 in.), discovered in 1954. Initially, cephalocarids were thought to be a living representation of what the primordial crustacean looked like. In recent years, that view has changed, with the Branchiopoda currently postulated to represent the most primitive of extant major crustacean taxa. In the classification of J. W. Martin and G. E. Davis (2001), the Branchiopoda are basal, whereas the Cephalocarida are positioned between the Remipedia and Maxillopoda, suggesting a more advanced evolutionary position for the class. Nonetheless, in their discussion of “most primitive,” Martin and Davis acknowledge that the question is still unresolved. At present, the Cephalocarida comprise ten species, assigned to five genera in one family. They have been found in flocculent surface deposits of mud or silty sand, from the intertidal zone down to depths of 5000 ft (1500 m), on the shores of all continents except Europe. Population densities up to an average of 16 individuals/ft<sup>2</sup> (177/m<sup>2</sup>) have been recorded.
Industry:Science
A group of unicellular, biflagellate, golden-brown algae characterized by a covering of extremely small (1–35 micrometers) interlocking calcite (the hexagonal form of calcium carbonate) plates called coccoliths. The plates show extinction crosses in a polarizing light microscope; however, detailed study requires the use of electron transmission or electron scanning microscopes. The Coccolithophorida are usually considered plants but possess also some animal characteristics. Botanists assign them to the class Haptophyceae (based on the possession of a haptonema, a threadlike organ of attachment) of the phylum Chrysophyta, and zoologists to the class Phytamastigophorea, superclass Mastigophora, subphylum Sarcomastigophora of the phylum Protozoa.
Industry:Science
A group of unit processes designed to separate, modify, remove, and destroy undesirable substances carried by wastewater from industrial sources. United States governmental regulations have been issued for volatile organic substances, designated priority pollutants, aquatic toxicity as defined by a bioassay, and in some cases nitrogen and phosphorus. As a result, sophisticated technology and process controls have been developed for treating industrial waste-water. It is also necessary to implement better water management and waste minimization practices to reduce waste loads and operating cost of treatment facilities.
Industry:Science
A group of unsegmented worms which have been variously recognized as an order, class, and phylum. They are now widely accepted as a separate phylum, Nemata (or Nematoda). When treated as a class, they were assigned either to the phylum Aschelminthes or to the phylum Nemathelminthes. In Aschelminthes they were ranked equally with Rotifera (Rotatoria), Gastrotricha, Kinorhyncha (Echinodera), and Nematomorpha (gordian or horsehair worms).
Industry:Science
A group of viruses that belong to the genus <i>Paramyxovirus</i> of the family Paramyxoviridae. The family includes two other genera, <i>Morbillivirus</i> and <i>Pneumovirus</i>. The genus <i>Parainfluenza</i> includes viruses such as mumps and Newcastle disease (in fowl and humans). Measles virus is a member of the genus <i>Morbillivirus</i>, and respiratory syncytial virus belongs to the genus <i>Pneumovirus</i>. Related members exist in nonhuman species; human measles virus is related to canine distemper and bovine rinderpest virus. Simian and bovine parainfluenza viruses also are known.
Industry:Science
A group of welding processes in which coalescence is produced by heating to suitable temperatures above 450°C and by using a filler metal that must have a liquidus temperature above 450°C and below the solidus temperature of the base metal. The filler metal is distributed between the closely fitted surfaces of the joint by capillary attraction. Brazing is distinguished from soldering in that the latter employs a filler metal having a liquidus below 450°C.
Industry:Science
A group that is recognized herein as consisting of the classes Actinopterygii (rayfin fishes) and Sarcopterygii (lungfishes and lobefins, or coelacanths, but excluding tetrapods). (Euteleostomi is a monophyletic group consisting of Actinopterygii and Sarcopterygii, including tetrapods.) The Sarcopterygii and Actinopterygii are well-defined phyletic lines which had evolved by the Middle Devonian, and many members of the two taxa persist today.
Industry:Science
