- 行业: Printing & publishing
- Number of terms: 178089
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- 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.
Electrical processes that take place in the lower atmosphere. This activity is ubiquitous and is of two kinds: the intense local electrification accompanying storms, and the much weaker fair-weather electrical activity occurring over the entire globe that is produced by the thousand or so electrified storms continuously in progress. The relative importance of the various mechanisms that cause storms to accumulate electrically charged particles is unknown, and the extent to which atmospheric electricity affects meteorological processes has yet to be determined. It is possible that atmospheric electricity may be important in forming precipitation and in providing energy to severe tornadoes.
Industry:Science
An ultramafic igneous rock composed of at least 90% olivine. Important accessory minerals (abundances usually less than 1%) found in different occurrences of dunite include chromian spinel, low- or high-calcium pyroxenes (enstatite and diopside), and plagioclase. If these minerals constitute greater than 10% of the rock, it is called chromitite, peridotite, or troctolite, respectively. Low-temperature alteration (less than 750°F or 400°C) causes hydration of olivine to the mineral serpentine and, where extensive, may transform dunite to the metamorphic rock serpentinite. Dunite was first described at Dun Mountain, New Zealand. The dun color is a characteristic feature of the weathered rock.
Industry:Science
Impairment in the use of spoken or written language caused by injury to the brain, which cannot be accounted for by paralysis or incoordination of the articulatory organs, impairment of hearing or vision, impaired level of consciousness, or impaired motivation to communicate. The language zone in the brain includes the portion of the frontal, temporal, and parietal lobes surrounding the sylvian fissure and structures deep to these areas. In right-handed persons, with few exceptions, only injury in the left cerebral hemisphere produces aphasia. Lateralization of language function is variable in left-handers, and they are at greater risk for becoming aphasic from a lesion in either hemisphere.
Industry:Science
Figures from the Joint United Nations Programme on human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) suggest that 40 million people are infected with HIV worldwide. Thus the need for an effective HIV vaccine is more pressing than ever. For individuals already infected, potent drugs are available to control the virus. However, these drugs often have significant toxicities and are difficult to afford in many parts of the world, particularly where they are most urgently needed. In addition, noncompliance with drug regimens is believed to contribute to the development of drug-resistant strains of HIV. Hence a vaccine remains the best hope of controlling the HIV pandemic.
Industry:Science
Any of the pebbles swallowed by animals and retained for a time in the gizzard or stomach, where they serve to grind up the food and in so doing become rounded and highly polished. Birds generally use such pebbles, as do some living reptiles, notably the crocodile and certain lizards. Some of the Mesozoic reptiles also used gastroliths. Articulated skeletons of the Plesiosaurs are generally associated with such highly polished cobbles, even when embedded in formations such as the Niobara chalk, which is otherwise free of gravel. In some instances as many as a half bushel of such stones have been found within the rib cage. Among the dinosaurs the great sauropods likewise used gizzard stones.
Industry:Science
Common designation for letters patent, which is a certificate of grant by a government of an exclusive right with respect to an invention for a limited period of time. A United States patent confers the right to exclude others from making, using, or selling the patented subject matter in the United States and its territories. A United States patent covering a process also, under certain conditions, prohibits the unlicensed sale in the United States of articles made by that process anywhere in the world. Portions of those rights deriving naturally from it may be licensed separately, as the rights to sell, to use, to make, to have made, and to lease. Any violation of this right is an infringement.
Industry:Science
For many years, functional molecules with multiple controllable and responsive properties have been at the center of major research efforts. Such molecules may combine, for example, the properties of polymers with response to heat, as in thermoplastic materials, or the properties of dyes with response to electricity, as in electrochromic materials. Responsive materials that display enhanced characteristics are gaining in versatility and leading to numerous new applications. Considerable progress has been made toward supramolecular assembly at interfaces. We will discuss the formation of films of metallosurfactants. Self-assembled monolayers, metallopolymers, and dendrimers will not be discussed.
Industry:Science
Bioprospecting is the search for new pharmaceutical, nutritional, or agricultural products from natural sources, including plants, animals, or microorganisms. Most commonly, it refers to the search for new medicines from plants or microbes. Plants have always been an important source of medicines, and approximately 25% of prescription pharmaceuticals contain a plant-derived ingredient. Examples of plant-derived drugs include the antihypertensive reserpine from <i>Rauvolfia serpentina</i>; vincristine and vinblastine, used to treat childhood leukemia and Hodgkin's disease, and derived from <i>Catharanthus roseus</i>; and taxol, derived from <i>Taxus brevifolia</i> and used to treat ovarian cancer.
Industry:Science
Autism is a neurodevelopmental condition that impairs the way a person relates to and communicates with other people. Persons with autism can also have unusual behaviors, such as insistence on sameness, obsessions, or stereotypic behaviors (for example, hand flapping, spinning, and toe walking). The condition varies greatly in the presenting symptoms, the timing of presentation, the range and severity of symptoms, and its association with other conditions. Although recognition of autism is increasingly common, the cause of autism and the reason for its increase remain unknown. With intensive early intervention, significant improvements in a large percentage of children with autism can be achieved.
Industry:Science
Charge-transfer-device detectors have become common in many systems used for chemical analysis, and are often an attractive alternative to photomultiplier tubes, photodiode arrays, and vidicons. Charge-transfer devices are solid-state, array detectors sensitive to photons from the far-infrared to the x-ray region of the spectrum. Today, most commercially available instruments use silicon-based detector technology, which has optimum sensitivity from the near-infrared to the x-ray region. Some important characteristics of properly operated scientific-grade charge-transfer devices are high sensitivity, large dynamic range, remarkably low dark current, very low read noise, and multichannel capability.
Industry:Science
