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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 large and diverse class of plants, commonly called green algae, in the chlorophyll <i>a-b</i> phyletic line (Chlorophycota). Estimated number of taxa varies widely; 560 genera and 8600 species are conservative estimates.
Industry:Science
A large and diverse order of conspicuous brown algae (Phaeophyceae) including such well-known seaweeds as <i>Fucus</i> and <i>Sargassum</i>. Definitive features include apical growth, production of sex organs in cavities, and a life history with only one somatic phase, which is diploid.
Industry:Science
A large and diverse order of the true mosses (Bryopsida), containing 13 families. Plants in the Dicranales generally have long, narrow leaves and deeply forked peristome teeth. The plants are erect and simple or merely forked and often woolly because of a dense covering of rhizoids among the leaves. The leaves, inserted in numerous rows, or rarely only two or three are often turned to one side or, when dry, crisped and curled. They are long-tapered, with a long, single costa and short or elongate cells which are sometimes bulging or papillose. The cells at the basal angles are often conspicuously differentiated. The capsules, terminal and generally exserted, may be erect and symmetric or inclined and asymmetric and often furrowed. An operculum is generally differentiated. The peristome (rarely lacking) commonly consists of 16 papillose or vertically pitted-striate teeth. The spores are spherical or rarely tetrahedral. The calyptra is cucullate or less commonly mitrate. Chromosome numbers 12 and 14 are common, but multiples of 10, 11, 13, and 15 are also known.
Industry:Science
A large and extremely diverse class of biflagellate algae (dinoflagellates) in the chlorophyll <i>a–c</i> phyletic line (Chromophycota). In protozoological classification, these organisms constitute an order, Dinoflagellida, of the class Phytomastigophora. Many taxonomists emphasize the distinctness of dinoflagellates by placing them in a separate division (Pyrrophyta or Pyrrhophyta) or even in a separate kingdom (Mesokaryota). More than 1200 species are known, classified into 18 orders and 54 families. Most are microscopic, but a few reach a diameter of 2 mm (0.08 in.). Cell shape is highly variable, with many planktonic species having elaborately modified surfaces. Dinoflagellates occur in marine, brackish, and fresh waters, frequently producing algal blooms. They may be benthic as well as planktonic, and a few are colonial. Ameboid, palmelloid, coccoid (with or without a gelatinous sheath), and filamentous forms are also known.
Industry:Science
A large and heterogeneous group of photosynthetic microorganisms, formerly referred to as blue-green algae. They had been classified with the algae because their mechanism of photosynthesis is similar to that of algal and plant chloroplasts; however, the cells are prokaryotic, whereas the cells of algae and plants are eukaryotic. The name cyanobacteria is now used to emphasize the similarity in cell structure to other prokaryotic organisms.
Industry:Science
A large and important genus of Australian forest trees; includes about 500 species in the family Myrtaceae. Only two species occur naturally outside Australia in the adjacent islands. Eucalypts occur throughout Australia except in coastal tropical and subtropical rainforests in Queensland and New South Wales and in temperate rainforests in Victoria and Tasmania. They are confined to water courses in the extensive arid zones of central and northwest Australia. Eucalypts grow from sea level to tree line (6600 ft or 2000 m).
Industry:Science
A large and relatively dense cloud of cold gas and dust in interstellar space from which new stars are born. Molecular clouds consist primarily of molecular hydrogen (H<sub>2</sub>) gas, have temperatures in the range 10–100 K, and contain 10<sup>31</sup>–10<sup>36</sup> kg of mass (for comparison the mass of the Sun is 2 × 10<sup>30</sup> kg). Molecular clouds are among the most massive gravitationally bound objects in the Milky Way Galaxy.
Industry:Science
A large aquatic reptile of the family Alligatoridae. Common usage generally restricts the name to the two species of the genus <i>Alligator</i>. The family also includes three genera (five species) of caiman. With the crocodiles and gharial (also spelled gavial), these are survivors of archosaurian stock and are considered close to the evolutionary line which gave rise to birds.
Industry:Science
A large aquatic rodent, <i>Ondatra zibethicus</i>, in the family Cricetidae and in the vole subfamily (Arvicolinae). It is known as the common muskrat (see <b>illustration</b>). It is dark reddish-brown, with a long, essentially naked, scaly, laterally compressed tail. The pelage is dense and shiny, and consists of a thick coat of underfur over which lies a covering of long, glossy guard hairs. The ears and eyes are relatively small for an animal of this size. The hindfeet bear webbed toes and are much larger than the front feet. The anterior faces of the upper incisors are yellowish-orange. The body length ranges about 14–16 in. (400–640 mm), with the tail about 7–12 in. (180–300 mm). The average weights of muskrats from Indiana are 1215 grams (2.67 lb) in adult males and 1247 grams (2.74 lb) in adult females, which is near average. The dental formula is I 1/1 C 0/0 Pm 0/0 M 3/3 = 16. The muskrat received its name because of its inguinal glands, which produce a musky odor.
Industry:Science
A large broad-leafed evergreen tree, <i>Bertholettia excelsa</i>, that grows wild in the forests of the Amazon valley of Brazil and Bolivia. The fruit is a spherical capsule, 3–6 in. (7.5–15 cm) in diameter and weighing 2–4 lb (0.9–1.8 kg) which, when mature, consists of an outer hard indehiscent husk about ½ in. (1.2 cm) thick enclosing an inner hard-shelled container or pod filled with about 20 rather triangular seeds or nuts.
Industry:Science
