- 行业: Printing & publishing
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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.
Ever since Manhattan socialite Ruth Harkness set foot in San Francisco in 1936 holding a baby giant panda—the first living panda to enter the United States—the world has been enamored with this enigmatic black and white bear. Yet, despite the giant panda's immense global popularity, this animal is listed as endangered under the World Conservation Union's Red List of Threatened Species (International Union for Conservation of Nature and Natural Resources, IUCN)—the de facto catalog of the world's most endangered species. Thus, how is it that the world's oldest surviving bear species—with an ancestry stretching back 7–8 million years—is considered endangered?
Industry:Science
If a function <i>f</i>(<i>x</i>) has the value 0 for <i>x</i> = <i>a</i>, <i>a</i> is a root of the equation <i>f</i>(<i>x</i>) = 0. The fundamental theorem of algebra states that any algebraic equation of the form <i>a</i><sub>0</sub><i>x</i><sup><i>n</i></sup> + <i>a</i><sub>1</sub><i>x</i><sup><i>n</i>−1</sup> + … + <i>a</i><sub><i>n</i>−1</sub><i>x</i> + <i>a</i><sub><i>n</i></sub> = 0, where the <i>a</i><sub><i>k</i></sub>'s are real numbers (<i>k</i> = 0, 1, …, <i>n</i>), has at least one root. From this it follows readily that such an equation has roots, real or complex, in number equal to the index (here <i>n</i>) of the highest power of <i>x</i>.
Industry:Science
Complex adaptive systems (CAS) constitute an emerging field of study in science, technology, the behavioral sciences, and management. This field has evolved from major knowledge areas, including mathematics, chemistry, physics, biology, organizational science, computer science, and engineering. Fundamentally, a system is complex when it is not amenable to linear understanding, simple cause-and-effect relationships, or other standard methods of systems analysis. Complex systems are ones in which patterns can be seen and understood, but the interplay of individual elements cannot be reduced to the study of such elements considered in isolation from one another.
Industry:Science
Elongate accumulations of sediment formed in the shallow coastal zone and separated from the mainland by some combination of coastal bays and their associated marshes and tidal flats. Barrier islands are typically several times longer than their width and are interrupted by tidal inlets. There are at least three possible explanations for their origin: (1) longshore spit development and subsequent cutting of inlets; (2) upward shoaling by wave action of subtidal longshore sand bars; and (3) drowning of coastal ridges. All three modes of origin may have occurred. The first two have been observed in recent times, the third is yet to be conclusively demonstrated.
Industry:Science
Both the U.S. Navy and the U.S. Army have considerable stockpiles of unguided munitions, such as the Navy's MK64 and the Army's MK483 155-mm (6.1-in.) spinning rounds. These rounds are relatively ineffective in the field because of their large miss distances, which result from a combination of gun pointing errors, shot-to-shot velocity variations, and aerodynamic disturbances that cause the flight path to deviate from the expected trajectory. As a consequence, the hit probability for a single projectile is very low. In fact, the single-shot hit probability for these unguided rounds is so low that over 350 rounds are required to achieve a hit probability of 90%.
Industry:Science
Before 1492, marking the beginning of modern transoceanic journeys, humans had established themselves on all habitable continents. These migrations are thought to have originated in Africa and to have occurred during the last 100,000 years. Today, populations that still live in the land they inhabited before 1492 are referred to as aboriginal populations. Thus, Europeans (such as Basques and Germans) are aboriginals of Europe, Africans (such as San and Pygmies) are aboriginals of Africa, and Native Americans are aboriginals of America. Most of these populations have few historical records of their origins and, in any case, these do not go back beyond 5000 years.
Industry:Science
Helium nuclei, which are abundant throughout the universe both as radioactive-decay products and as key participants in stellar fusion reactions. Alpha particles can also be generated in the laboratory, either by ionizing helium or from nuclear reactions. They expend their energy rapidly as they pass through matter, primarily by taking part in ionization processes, and consequently have short penetration ranges. Numerous technological applications of alpha particles can be found in fields as diverse as medicine, space exploration, and geology. Alpha particles are also major factors in the health concerns associated with nuclear waste and other radiation hazards.
Industry:Science
Equine protozoal myeloencephalitis (EPM) is a treatable but frequently debilitating central nervous system disease of the horse. It is probably the most commonly diagnosed equine neurologic disease in the Western Hemisphere and results in considerable economic and personal loss. Although nervous disorders of the horse have been known for centuries, the unique pathology associated with EPM was not recognized until the early 1960s. The disease was initially known as segmental myelitis and was found in horses from the northeastern United States. Subsequent cases have been reported among native horses throughout North America, as well as in Central and South America.
Industry:Science
Arctic sea ice has undergone drastic change in recent years, emphasizing the critical role of satellite remote sensing to monitor Arctic change with a frequent coverage over large regions. Optical and multispectral sensors require clear sky and sufficient solar lighting. Microwave radiometers measure ice concentration, the fraction of ice-covered area over the total area, but cannot accurately detect different sea-ice classes. The satellite scatterometer, defined as a stable and accurate radar, is emerging as a versatile sensor for Earth observations and providing new capabilities for sea-ice classification and melt detection regardless of cloud cover and darkness.
Industry:Science
During the summer months of 2007, seven fatal infections caused by <i>Naegleria fowleri</i> occurred in Florida, Texas, and Arizona. All cases were in boys and young men who participated in recreational water sports at freshwater lakes during the summer. At the time, Florida was suffering from drought conditions through much of the state, leading to lowered water levels and increased temperature of the water. Arizona was in moderate to severe drought conditions during most of 2007, while Texas experienced typical high temperatures and had drought conditions present in 2005, 2006, and 2007. What connection, if any, exists between drought and these tragic fatalities?
Industry:Science
