- 行业: Printing & publishing
- Number of terms: 178089
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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.
For any collection of species, given information on their attributes and a phylogeny that describes their shared hierarchy of descent, it is possible to reconstruct the characteristics of the ancestors of the species. This is an intriguing idea that offers the possibility of glimpsing the past, discovering how traits evolve, and understanding their function. Reconstructions of the ancestral states of organisms are increasingly used to investigate ancient features of life on Earth and to test ecological and evolutionary hypotheses. They are also being used to reconstruct proteins and genes that existed millions of years ago.
Industry:Science
By the midtwentieth century most scientists shared the view that the primate order consisted of the living and fossil tree shrews, lemurs, galagos, lorises, tarsiers, monkeys, and apes, including humans. The fossils of three extinct radiations known primarily from the Paleocene and Eocene of western Europe and North America were also included: the Plesiadapiformes (sometimes referred to as Archaic Primates), the Adapiformes, and the Omomyiformes. Primates were seen as the archetypal arboreal mammals and were consequently thought to have evolved most of their characteristics as a direct result of the demands of arboreal life.
Industry:Science
Cell growth and proliferation are regulated by various intracellular and environmental cues, including nutrients, growth factors, energy, and stress. Recent studies have suggested that the mammalian target of rapamycin (mTOR) plays a key role in sensing and integrating these diverse signals, thus placing mTOR as a central regulator of cell growth and proliferation. Interest in mTOR is also spawned by clinical applications of mTOR inhibitors in transplantation, prevention of coronary restenosis (reconstriction or renarrowing of a coronary artery after it has been treated with angioplasty or stenting), and treatment of cancer.
Industry:Science
Crystalline substances which have a permanent spontaneous electric polarization (electric dipole moment per cubic centimeter) that can be reversed by an electric field. In a sense, ferroelectrics are the electrical analog of the ferromagnets, hence the name. The spontaneous polarization is the so-called order parameter of the ferroelectric state, just as the spontaneous magnetization is the order parameter of the ferromagnetic state. The names Seignette-electrics or Rochelle-electrics, which are also widely used, are derived from the name of the first substance found to have this property, Seignette salt or Rochelle salt.
Industry:Science
Any of the viruses that infect fungi (mycoviruses). In general these viruses are spheres of 30–45-nanometer diameter composed of multiple units of a single protein arranged in an icosahedral structure enclosing a genome of segmented double-stranded ribonucleic acid (dsRNA). Viruses are found in most species of fungi, where they usually multiply without apparent harm to the host. Most fungal viruses are confined to closely related species in which they are transmitted only through sexual or asexual spores to progeny or by fusion of fungal hyphae (filamentous cells). Some fungal strains are infected with multiple virus species.
Industry:Science
Common name for the plant <i>Colocasia esculenta</i>, including the variety <i>antiquorum</i> (taro). These plants are among the few edible members of the aroid family (Araceae). Native to southeastern Asia and Malaysia, the plants supply the people with their most important food. The edible corms (underground stems) support a cluster of large leaves 4–6 ft (1.2–1.8 m) long. A main dish in the Polynesian menu is poi, a thin, pasty gruel of taro starch, often fermented, which is frequently formed into cakes for baking or toasting. The raw corms are baked or boiled to eliminate an irritating substance present in the cells.
Industry:Science
CT (computed, computer, or computerized tomography) is a technology that enables highly detailed and nondestructive three-dimensional examination of solid objects using x-rays. It is perfectly suited for paleontology, as fossil material is often precious and irreplaceable, and information on internal structures is crucial for placing ancient species into their proper anatomical, and ultimately evolutionary, context. In the past, comparable data could be obtained only though serial grinding, in which a specimen was slowly ground away and illustrations made at small intervals, a process that is slow, laborious, and destructive.
Industry:Science
Graphs of the intensity of radiation from astronomical objects as they change with time. Variations may be caused by the changing perspective from the Earth of two stars in orbit around each other, by pulsations that change an individual star's size and surface temperature, by mass ejection or accretion, by explosions, by beams of radiation sweeping across the line of sight from the Earth, or by clouds of very high-energy electrons in powerful magnetic fields. The information contained in the light curve includes the timing of events, such as eclipses or pulses, and the amplitude of changes in the radiation received at Earth.
Industry:Science
Computer systems that cannot be programmed by the user because they are preprogrammed for a specific task and are buried within the equipment they serve. The term derives from the military, where computer systems are generally activated by the flip of a switch or the push of a button. For example, a military aircraft pilot may wish to turn on the countermeasures equipment with a switch. There is no need for the pilot to be involved with the computer. The same holds true for a soldier who may direct a ground-to-ground missile against a target tank by the push of a button. In both cases, an embedded computer quickly goes to work.
Industry:Science
Any of five species of fishes which compose the family Esocidae in the order Esociformes, known by a variety of names such as pickerel and muskellunge. These fishes are voracious predators with an elongated beaklike snout and sharp teeth. The head is partly scaled and the body is covered with cycloid scales that have deeply scalloped edges. The body is cylindrical and compressed; thus, these fishes are well adapted for rapid movements as they dart after prey. They prey upon each other, as well as other fishes, amphibians, small aquatic birds and mammals, and rats. All species are edible but are considered second-rate game fishes.
Industry:Science
