- 行业: Printing & publishing
- Number of terms: 178089
- Number of blossaries: 0
- Company Profile:
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.
Thalidomide is the most infamous drug in the history of the world. It was formulated in the mid-1950s by Chemie Grünenthal, a West German cosmetic subsidiary, in search of new antibiotic drugs. Thalidomide had no antibiotic properties but, as no lethal dose could be found in rats, the company decided to test it in humans, where it was discovered to have a potent hypnotic effect. The drug was first marketed as a sleeping pill on October 1, 1957, under the trade name Contergan. Six months later Distillers Company Ltd. of Great Britain began to sell the drug under their trade name Distaval. The drug was marketed over the counter and was heavily advertised as the only completely safe sleeping pill. By summer 1960 thalidomide sales reached an all-time high, outselling the second-leading sleeping pill in Europe by 5:1.
Industry:Science
The equilibrium potential difference between two conducting phases in contact, most often an electronic conductor such as a metal or semiconductor on the one hand, and an ionic conductor such as an electrolyte solution (a solution containing ions) on the other. Electrode potentials are not experimentally accessible, but the differences in potential between two electronic conductors making contact with the same ionic conductor (that is, the difference between two electrode potentials) can be measured. A useful scale of electrode potentials can therefore be obtained when a particular electrode potential is set equal to zero by definition. There are several conventions, based on different definitions of the zero point on the scale of electrode potential, but all tables use the so-called standard hydrogen convention.
Industry:Science
The largest discrete structure in the Earth's interior, known as the African superplume, has been found beneath southern Africa within the outer layer known as the mantle. The mantle, comprising solid but flexible rock about 3000 km (1800 mi) thick, is where the flow associated with plate tectonics occurs. While it is not certain what the African superplume is exactly, it may be a giant upwelling of mantle material. Southern Africa's high topography and unusual land surface are indicative of uplift that may be dynamically supported by this rising superplume. This interpretation is qualitatively consistent with a range of observations showing that Africa is experiencing active intraplate volcanism and rifting, as well as with seismic and other quantitative evidence of anomalous mantle features below the continent.
Industry:Science
The giant squid, <i>Architeuthis</i>, is renowned as the largest invertebrate in the world. The largest squid so far recorded, which measured 55 ft (16.8 m) in total length (from tip of the fins to tip of the longest tentacle), was found stranded on a Newfoundland seashore in 1878. Considerable effort to view this elusive creature in its deep-sea habitat has been expended, but until the morning of September 30, 2004, no one had ever reported an observation of a live giant squid in the wild. On that morning, images of a live giant squid in its natural environment were captured by an underwater digital camera and depth recorder system in the deep sea off the Ogasawara Islands in the western North Pacific. This is the first evidence showing the behavior and biological characteristics of a live giant squid in the wild.
Industry:Science
Superimposed on generally warm climates of the early Tertiary Period was an abrupt and extreme warming interval at the end of the Paleocene Epoch some 55 million years ago. This event, the latest Paleocene thermal maximum (LPTM), coincided with a mass extinction of deep-sea organisms and a sudden radiation of terrestrial mammalian orders, including primates. The LPTM also was characterized by a global carbon-isotope excursion that was caused by a massive injection of carbon into the ocean and atmosphere. All of these phenomena were likely related to the escape of large amounts of biogenic methane from gas hydrate deposits on the sea floor. Although many details surrounding the LPTM are poorly known, it is probably the best past analog for understanding long-term effects of future fossil fuel inputs to the atmosphere.
Industry:Science
The study of triangles and the trigonometric functions. One common use for trigonometry is to measure heights and distances that are awkward or impossible to measure by ordinary means. Surveyors use it to find heights of mountains and distances across lakes and countries; engineers use it in the design of large structures and roads; astronomers use it in accurate measurements of the time and in locating the position of objects in the sky; and navigators on the sea and in the air use it to find latitudes, longitudes, and direction. Trigonometry has evolved from use by surveyors, engineers, and navigators to applications involving ocean tides, the rise and fall of food supplies in certain ecologies, brain-wave patterns, the analysis of alternating-current electricity, and many other phenomena of a vibratory character.
Industry:Science
The art or practice of designing computer systems. Just as the architecture of a building describes its overall structural concept and principal features, the architecture of a computer system consists of a description of the overall layout and major features of a computer system. In both cases, we are concerned with how the object, whose architecture we are describing, appears to the user. In computer architecture, the user is not the final user of the system, but the person who writes computer programs to be run on the system. Compared to the architecture of buildings, which is largely an issue of esthetics, the architecture of a computer system is principally about efficiency and economy of operation. There may be an esthetic dimension to computer architecture, but when present it is distinctly lower in importance.
Industry:Science
The combined evidence from molecular systematics, comparative morphology, and primatology has established that the African great apes—gorillas and chimpanzees—are more closely related to humans than they are to the Asian orangutan and other extant primates. Since our closest primate relatives are restricted today to Equatorial Africa, it can be deduced (as Charles Darwin and Thomas Huxley did more than a century ago) that humans are descended from a last common ancestor that also lived in Africa. Using a “molecular clock” model, in which the time scale of genetic change is calibrated against the fossil record, and based on the degree of genetic similarity between humans and chimpanzees (we share about 98% of our genomes), scientists can infer that humans diverged from the African apes about 6–7 million years ago (Ma).
Industry:Science
The device in the power train of a motor vehicle that provides different gear ratios between the engine and drive wheels, as well as neutral and reverse. An internal combustion engine develops relatively low torque at low speed and maximum torque at only one speed, with the crankshaft always rotating in the same direction. To meet the tractive-power demand of the vehicle, the transmission converts the engine speed and torque into an output speed and torque in the selected direction for the final drive. This arrangement permits a smaller engine to provide acceptable performance and fuel economy while moving the vehicle from standstill to maximum speed. The transmission may be a separate unit as in front-engine rear-drive vehicles or may be combined with the drive axle to form a transaxle as in most front-drive vehicles.
Industry:Science
The <i>Hipparcos</i> space astronomy mission was dedicated to the very accurate measurement of star positions and star motions in space. The satellite was designed, built, and operated under the responsibility of the European Space Agency. It was launched in August 1989 and operated until mid-1993. The two resulting star catalogs were completed and published in 1997: the <i>Hipparcos Catalogue</i> is a high-accuracy compilation of nearly 120,000 star positions, distances, and motions; the <i>Tycho Catalogue</i> is a lower-accuracy catalog of slightly more than 1 million stars. Together they represent astronomers' best understanding of the spatial distribution, space motion, and corresponding physical properties of stars in the solar neighborhood. The experiment was carried out by a collaboration of about 200 scientists.
Industry:Science
