ultrasonics: Therapy and surgery: …of kidney stones, known as endoscopic ultrasonic disintegration, uses a small metal rod inserted through the skin to deliver ultrasound in the 22- to 30-kilohertz frequency region.

endoscopy, medical examination of the interior of the body, usually through a natural body opening, by the insertion of a flexible, lighted optical shaft or open tube. Instruments used include the endoscope, a flexible tube for examination of the esophagus, stomach, and duodenum, and the

virus: The cycle of infection: …coated vesicle fuses with cytoplasmic endosomes (membrane-enclosed vesicles) and then with cell organelles called lysosomes, which are membrane-enclosed vesicles containing enzymes. In an acidic environment, the membrane of an enveloped virus fuses with the endosome membrane, and the viral nucleocapsid is released into the cytoplasm. Nonenveloped viruses presumably undergo a…

endosperm, tissue that surrounds and nourishes the embryo in the seeds of angiosperms (flowering plants). In some seeds the endosperm is completely absorbed at maturity (e.g., pea and bean), and the fleshy food-storing cotyledons nourish the embryo as it germinates. In others, some of the endosperm

Ferdinand Cohn: …and germination of spores (called endospores) in certain bacteria, particularly in Bacillus subtilis. He was also the first to note endospores’ resistance to high temperatures, and by his observations he was able to refute contemporary experiments that seemed to lend support to the theory of spontaneous generation. Cohn explained the…

arachnid: Support, skeleton, and exoskeleton: …hard internal structure called the endosternite, which anchors muscles.

amphioxus: The endostyle corresponds to the thyroid in vertebrates, since it seems to produce iodinated, tyrosine molecules, which may function as regulatory substances, much like hormones, in amphioxi.

therapeutics: Minimally invasive surgery: Traditional open surgical techniques are being replaced by new technology in which a small incision is made and a rigid or flexible endoscope is inserted, enabling internal video imaging. Endoscopic procedures (endoscopy) are commonly performed on nasal sinuses, intervertebral disks, fallopian tubes,…

algae: Distribution and abundance: …general sense these are called endosymbionts. Specifically, endozoic endosymbionts live in protozoa or animals such as shelled gastropods, whereas endophytic endosymbionts live in fungi, plants, or other algae.

cell: The endosymbiont hypothesis: Mitochondria and chloroplasts are self-dividing; they contain their own DNA and protein-synthesizing machinery, similar to that of prokaryotes. Chloroplasts produce ATP and trap photons by mechanisms that are complex and yet similar to those of certain prokaryotes. These phenomena have led to the…

algae: Distribution and abundance: …general sense these are called endosymbionts. Specifically, endozoic endosymbionts live in protozoa or animals such as shelled gastropods, whereas endophytic endosymbionts live in fungi, plants, or other algae.

arteriosclerosis: …of a blood vessel (the endothelium of the intimal layer) becomes injured. Some factors that cause mechanical damage to the endothelium are high cholesterol and triglycerides (a type of lipid, or fat), high blood pressure, and tobacco smoke. People who have an abnormally large amount of cholesterol or other lipids…

Robert F. Furchgott: The molecule, which he named endothelium-derived relaxing factor (EDRF), signals smooth muscle cells in blood vessel walls to relax, dilating the vessels. Furchgott’s work would eventually be linked with research done by Murad in 1977, which showed that nitroglycerin and several related heart drugs induce the formation of nitric oxide,…

endotherm, so-called warm-blooded animals; that is, those that maintain a constant body temperature independent of the environment. The endotherms primarily include the birds and mammals; however, some fish are also endothermic. If heat loss exceeds heat generation, metabolism increases to make up

chemical reaction: Energy considerations: The opposite of endothermic is exothermic; in an exothermic reaction, energy as heat is evolved. The more general terms exoergic (energy evolved) and endoergic (energy required) are used when forms of energy other than heat are involved.

liquid: Endothermic and exothermic solutions: When two substances mix to form a solution, heat is either evolved (an exothermic process) or absorbed (an endothermic process); only in the special case of an ideal solution do substances mix without any heat effect. Most simple molecules mix with…

Ascomycota: chestnut blight (Cryphonectria parasitica), and apple scab (Venturia inequalis).

Endothyra, extinct genus of Foraminifera, protozoans with a readily preservable shell; found as fossils in Devonian to Triassic marine rocks (between 416 million and about 200 million years old). Endothyra, characterized by a tightly coiled shell, is sometimes found in very large numbers; it is

endotoxin, toxic substance bound to the bacterial cell wall and released when the bacterium ruptures or disintegrates. Endotoxins consist of lipopolysaccharide and lipoprotein complexes. The protein component determines its foreign (antigenic) nature; the polysaccharide component determines the

conifer: Roots: …species have vesicular-arbuscular mycorrhizae, called endomycorrhizae because the fungal hyphae actually penetrate the cells of the roots. All of the Pinaceae, and only the Pinaceae, have the other kind of root symbiosis, called ectomycorrhizal because the fungi sheath the rootlets and hyphae pass between the outer root cells without penetrating…

Church of Jesus Christ of Latter-day Saints: Institutions and practices: Baptism for the dead, endowment (a rite of adult initiation in which blessings and knowledge are imparted to the initiate), and the sealing of husbands, wives, and children (which may also be undertaken by proxy for the dead) are essential ceremonies that take place in the temple. During the…

heredity: Heredity and environment: A notion that was widespread among pioneer biologists in the 18th century was that the fetus, and hence the adult organism that develops from it, is preformed in the sex cells. Some early microscopists even imagined that they saw…

seed: Agents of dispersal: …carried can be emphasized, distinguishing endozoochory, seeds or diaspores carried within an animal; epizoochory, seeds or diaspores accidentally carried on the outside; and synzoochory, seeds or diaspores intentionally carried, mostly in the mouth, as in birds and ants.

John Updike: Endpoint, and Other Poems, published posthumously in 2009, collects poetry Updike had written between 2002 and a few weeks before he died; it takes his own death as its primary subject. Selected Poems (2015) broadly surveys his poetic career. Higher Gossip, a collection of commentaries,…

Hungary: The early kings: …followed on the throne by Andrew (Endre) I, of a collateral branch of the house of Árpád, who was killed in 1060 while fleeing from a battle lost to his brother, Béla I. After Béla’s death there was a further conflict between his sons, Géza and Ladislas (László), and Andrew’s…

aldrin (C12H8Cl6), one of the several isomers (compounds with the same composition but different structures) of hexachlorohexahydrodimethanonaphthalene, a chlorinated hydrocarbon formerly used as an insecticide. Aldrin was first prepared in the late 1940s and is manufactured by the reaction of

decision making: Satisficing and bounded rationality: …missions through what Simon called ends-means chains. Leaders set the organizational mission, find a set of means for achieving the mission, take each of those means as a subgoal, and then find means for the subgoals and so on, until goals exist for every member of the organization. Leaders thus…

Ernest Shackleton: …Pole, but the expedition ship Endurance was trapped in ice off the Caird coast and drifted for 10 months before being crushed in the pack ice. The members of the expedition then drifted on ice floes for another five months and finally escaped in boats to Elephant Island in the…

Daniel Lieberman: …Lieberman and Bramble outlined the endurance-running hypothesis, which states that the ability of humans to run long distances is an adaptation that originated approximately two million years ago with the emergence of the genus Homo. They noted that several features that facilitate endurance running first appeared in H. habilis and…

synthetic biology: BioBricks and xeno-nucleic acids: …synthetic biology was American bioengineer Drew Endy, who founded the nonprofit BioBricks Foundation. Endy was developing a catalogue of information needed to synthesize basic biological parts, or “bricks,” from DNA and other molecules. Other scientists and engineers were able to use this information to build whatever biological products they wanted,…

John Keats: Early works: …Canterbury and began work on Endymion, his first long poem. On his return to London he moved into lodgings in Hampstead with his brothers. Endymion appeared in 1818. This work is divided into four 1,000-line sections, and its verse is composed in loose rhymed couplets. The poem narrates a version…

Endymion, in Greek mythology, a beautiful youth who spent much of his life in perpetual sleep. Endymion’s parentage varies among the different ancient references and stories, but several traditions say that he was originally the king of Elis. According to one tradition, Zeus offered him anything

Benjamin Disraeli: Second administration: …his party leadership and finished Endymion (3 vol., 1880), a mellow, nostalgic political novel viewing his early career. His health failed rapidly, and, a few days after his burial in the family vault at Hughenden, Queen Victoria came to lay a wreath upon the tomb of her favourite prime minister.

bluebell: …clusters of English bluebell, or wild hyacinth (Hyacinthoides non-scripta), and Spanish bluebell (H. hispanica) are borne on plants about 30 cm (1 foot) tall. Both species are cultivated as garden ornamentals.

Pierre-Narcisse, Baron Guérin: …for colour and atmosphere, is Enée racontant à Didon les malheurs de la ville de Troie (1817). He was director of the Académie de France in Rome from 1822 to 1828.

Ninazu: …deity, the city god of Enegir, which was located on the Euphrates River between Larsa and Ur in the southern orchard region. Ninazu was also the city god of Eshnunna (modern Tall al-Asmar in eastern Iraq). Ninazu, whose name means “Water Knower,” was primarily an underworld deity, although the exact…

Heinrich von Veldeke: …of Thuringia, Heinrich completed the Eneit, modeled on the French Roman d’Eneas rather than directly on Virgil’s Aeneid. Eneit was written not in Heinrich’s native Flemish but in the Franconian literary language of such works as Eilhart von Oberg’s Tristrant und Isalde. Following its French example, Eneit greatly expands the…

Heinrich von Veldeke: …of Thuringia, Heinrich completed the Eneit, modeled on the French Roman d’Eneas rather than directly on Virgil’s Aeneid. Eneit was written not in Heinrich’s native Flemish but in the Franconian literary language of such works as Eilhart von Oberg’s Tristrant und Isalde. Following its French example, Eneit greatly expands the…

Endesa: …and the Italian energy company Enel. Two years later Enel purchased Acciona’s stake, thereby taking full control of Endesa.

enema, procedure in which water or other fluids are injected via the rectum into the lower intestine. Enemas stimulate defecation and thus are most commonly used to treat occasional constipation. They also may be used to cleanse the colon, to assist in the diagnosis of certain conditions, or to

Paul Mazursky: Films of the 1980s: Mazursky next made Enemies, A Love Story (1989), an adaptation of Isaac Bashevis Singer’s novel about a Holocaust survivor (Ron Silver) who is living in New York City with his wife (Margaret Sophie Stein) while also having an affair with a married woman (Lena Olin). The situation becomes…

José Lezama Lima: Enemigo rumor (1941; “Hostile Murmurs,” or “Enemy Rumour”) reveals, in addition to aesthetic preoccupations about the essence of poetry, the poet’s belief that the act of creation is laden with religious and metaphysical possibilities. In Aventuras sigilosas (1945; “Surreptitious Adventures”), he recreates incidents of his…

Robin Maugham: …is about homosexuals: a play, Enemy (1970), which brings a British and a German soldier into confrontation alone in the desert, charts their doomed friendship; and The Last Encounter (1972), which portrays Charles George (“Chinese”) Gordon of Khartoum as a man as unsure of his destiny as of his sexual…

Johnson v. Eisentrager: …ruled in 1950 that nonresident enemy aliens do not have the legal right to petition U.S. courts for writs of habeas corpus—a prisoner’s petition requesting that the court determine the legality of his or her incarceration. This landmark Supreme Court case was reexamined in 2008 in light of the detention…

enemy combatant, extraordinary legal status developed by the administration of Pres. George W. Bush (2001–09) that permitted U.S. military authorities to detain indefinitely and without charge individuals so designated and to deny them other rights and protections afforded under the international

Oliver La Farge: …set in Central America, while The Enemy Gods (1937) centres on the inability of the Navajo to adapt to white civilization. Long Pennant (1933) and The Copper Pot (1942) have New Englanders as their main characters. La Farge’s short stories were collected in All the Young Men (1935) and A…

Steve McQueen: …of Henrik Ibsen’s stage play An Enemy of the People (1977), a drama about a scientist’s efforts to expose his community’s polluted water system. The film was decidedly a labour of love for the actor, but it was poorly received and barely released theatrically. In 1980 McQueen twice played a…

An Enemy of the People, five-act drama by Henrik Ibsen, published in 1882 as En folkefiende and performed in 1883. An Enemy of the People concerns the actions of Doctor Thomas Stockmann, a medical officer charged with inspecting the public baths on which the prosperity of his native town depends.

English literature: Anglo-American Modernism: Pound, Lewis, Lawrence, and Eliot: His experimental play Enemy of the Stars, published in Blast in 1914, and his experimental novel Tarr (1918) can still surprise with their violent exuberance.

Gene Hackman: …films included Get Shorty (1995), Enemy of the State (1998), The Royal Tennenbaums (2001), Runaway Jury (2003), and Welcome to Mooseport (2004).

Copper Age, early phase of the Bronze Age

R. Buckminster Fuller: Life: …geometry that he called “Energetic-Synergetic geometry.” The basic unit of this system is the tetrahedron (a pyramid shape with four sides, including the base), which, in combination with octahedrons (eight-sided shapes), forms the most economic space-filling structures. The architectural consequence of the use of this geometry by Fuller was…

Wilhelm Ostwald: Other notable activities of Wilhelm Ostwald: …world that he named “energetics.” Second, he asserted a form of positivism in the sense of rejecting theoretical concepts that are not strictly founded on empirical grounds. Although energetics found few adherents, the latter position found many contemporary proponents, such as the physicist-philosophers Ernst Mach in Austria and Pierre…

Energia, Soviet heavy-lift launch vehicle. In 1976 approval was given for development of Energia (named for the design bureau that developed it) and its primary mission, the space shuttle Buran. Energia could lift 100,000 kg (220,000 pounds) to low Earth orbit, slightly more than the American

Energia, Russian aerospace company that is a major producer of spacecraft, launch vehicles, rocket stages, and missiles. It built the world’s first intercontinental ballistic missile and the first artificial satellite, Sputnik, and pioneered the development and operation of Soviet space stations

reproduction: Multiple fission: …metabolism, which he called an energid. Cell reproduction, therefore, might be considered a special case of energid reproduction.

energy, in physics, the capacity for doing work. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms. There are, moreover, heat and work—i.e., energy in the process of transfer from one body to another. After it has been transferred, energy is always

band theory, in solid-state physics, theoretical model describing the states of electrons, in solid materials, that can have values of energy only within certain specific ranges. The behaviour of an electron in a solid (and hence its energy) is related to the behaviour of all other particles around

climate: The biosphere and Earth’s energy budget: Biogenic gases in the atmosphere play a role in the dynamics of Earth’s planetary radiation budget, the thermodynamics of the planet’s moist atmosphere, and, indirectly, the mechanics of the fluid flows that are Earth’s planetary wind systems. In addition, human cultural and economic…

cogeneration, in power systems, use of steam for both power generation and heating. High-temperature, high-pressure steam from a boiler and superheater first passes through a turbine to produce power (see steam engine). It then exhausts at a temperature and pressure suitable for heating purposes,

solar cell: …based on the world’s projected energy consumption by 2030 suggest that global energy demands would be fulfilled by solar panels operating at 20 percent efficiency and covering only about 496,805 square km (191,817 square miles) of Earth’s surface. The material requirements would be enormous but feasible, as silicon is the…

energy conversion, the transformation of energy from forms provided by nature to forms that can be used by humans. Over the centuries a wide array of devices and systems has been developed for this purpose. Some of these energy converters are quite simple. The early windmills, for example,

magnetism: Magnetization effects in matter: The energy density in a magnetic field is given in the absence of matter by 12B2/μ0; it is measured in units of joules per cubic metre. The total magnetic energy can be obtained by integrating the energy density over all space. The direction of the magnetic…

energy drink, any beverage that contains high levels of a stimulant ingredient, usually caffeine, as well as sugar and often supplements, such as vitamins or carnitine, and that is promoted as a product capable of enhancing mental alertness and physical performance. Energy drinks are distinguished

biosphere: The flow of energy: Life on Earth depends on the harnessing of solar energy by the process of photosynthesis. Photosynthetic plants convert solar energy into the chemical energy of living tissue, and that stored chemical energy flows into herbivores, predators, parasites,

band gap, in solid-state physics, a range of energy levels within a given crystal that are impossible for an electron to possess. Generally, a material will have several band gaps throughout its band structure (the continuum of allowed and forbidden electron energy levels), with large band gaps

biofuel: Economic and environmental considerations: In the United States the Energy Independence and Security Act of 2007 mandated the use of 136 billion litres (36 billion gallons) of biofuels annually by 2022, more than a sixfold increase over 2006 production levels. The legislation also requires, with certain stipulations, that 79 billion litres (21 billion gallons)…

nuclear power: World nuclear power: The Energy Information Administration (EIA), a statistical arm of the U.S. Department of Energy, has projected that world electricity generation between 2005 and 2035 will roughly double (from more than 15,000 terawatt-hours to 35,000 terawatt-hours) and that generation from all energy sources except petroleum will continue…

military intelligence: Energy: Energy intelligence specifically addresses the location and size of foreign energy resources; how these resources are used and allocated; foreign governments’ energy policies, plans, and programs; new or improved foreign energy technologies; and the economic and security aspects of foreign energy supply, demand, production, distribution,…

energy level, in physics, any discrete value from a set of values of total energy for a subatomic particle confined by a force to a limited space or for a system of such particles, such as an atom or a nucleus. A particular hydrogen atom, for example, may exist in any of several configurations,

energy level, in physics, any discrete value from a set of values of total energy for a subatomic particle confined by a force to a limited space or for a system of such particles, such as an atom or a nucleus. A particular hydrogen atom, for example, may exist in any of several configurations,

microgeneration: Net metering: …United States, under the 2005 Energy Policy Act, all public electric utilities are required to make net metering available to customers on request. The process of net metering credits the bills of nonutility net energy producers when they add electricity to the grid, which reduces the amount they pay for…

trophic pyramid, the basic structure of interaction in all biological communities characterized by the manner in which food energy is passed from one trophic level to the next along the food chain. The base of the pyramid is composed of species called autotrophs, the primary producers of the

Atomic Energy Commission: government under the Energy Reorganization Act of 1974 disbanded the AEC and divided its functions between two new agencies: the Nuclear Regulatory Commission (q.v.), which regulates the nuclear-power industry; and the Energy Research and Development Administration, which was disbanded in 1977 when the Department of Energy was created.

radiation measurement: Scintillators: One consequence is that the energy resolution of scintillators is rather poor owing to the statistical fluctuations in the number of carriers actually obtained. For example, the best energy resolution from a scintillator for 0.662 MeV gamma rays (a common standard) is about 5 to 6 percent. By comparison, the…

geology: Oil and natural gas: …yet make them attractive alternative energy resources.

Environmental Protection Agency: …Policy Act (1982) and the Energy Star program (1992); the latter was implemented to rate the usage costs and energy efficiency of household appliances and other electronic devices. This period also saw the development of the Emergency Planning and Community Right-to-Know Act (EPCRA), which allowed local communities to know the…

energy transfer, the change of energy from one form to another. According to the first law of thermodynamics, energy can be neither created nor destroyed; in other words, the total energy of the universe remains constant. For example, when a block slides down a slope, the potential energy of the

biosphere: The flow of energy: Life on Earth depends on the harnessing of solar energy by the process of photosynthesis. Photosynthetic plants convert solar energy into the chemical energy of living tissue, and that stored chemical energy flows into herbivores, predators, parasites,

conservation of energy, principle of physics according to which the energy of interacting bodies or particles in a closed system remains constant. The first kind of energy to be recognized was kinetic energy, or energy of motion. In certain particle collisions, called elastic, the sum of the

radiation measurement: Modes of operation: …a certain amount of charge Q as a result of depositing its energy in the detector material. For example, in a gas, Q represents the total positive charge carried by the many positive ions that are produced along the track of the particle. (An equal charge of opposite sign is…

equipartition of energy, law of statistical mechanics stating that in a system in thermal equilibrium, on the average, an equal amount of energy will be associated with each degree of freedom. (A particle moving through space has three degrees of freedom because three coordinates are needed to

U.S. Department of Energy, executive division of the U.S. federal government responsible for administering national energy policy. Established in 1977, it promotes energy efficiency and the use of renewable energy. Its national security programs serve to develop and oversee nuclear-energy

automobile: Safety systems: Interior-impact energy-absorbing devices augment restraint systems by absorbing energy from the occupant while minimizing injuries. The energy-absorbing steering column, introduced in 1967, is a good example of such a device. Instrument panels, windshield glass, and other surfaces that may be struck by an unrestrained occupant may…

George Enesco was a Romanian violinist and composer, known for his interpretations of Bach and his eclectic compositions. At age seven Enesco went to the Vienna Conservatory, where he studied violin. In 1894 he became acquainted with Johannes Brahms, whose formal symphonic developments he later

George Enesco was a Romanian violinist and composer, known for his interpretations of Bach and his eclectic compositions. At age seven Enesco went to the Vienna Conservatory, where he studied violin. In 1894 he became acquainted with Johannes Brahms, whose formal symphonic developments he later

Enets, an indigenous Arctic people who traditionally resided on the east bank of the lower Yenisey River of Russia. They numbered about 300 in the Russian census of 2002. The Enets live in the Arctic tundra, a region of permafrost, and are divided into two major groups, the so-called Tundra Enets

Enets, an indigenous Arctic people who traditionally resided on the east bank of the lower Yenisey River of Russia. They numbered about 300 in the Russian census of 2002. The Enets live in the Arctic tundra, a region of permafrost, and are divided into two major groups, the so-called Tundra Enets

Samoyedic languages: …subgroup consists of Nenets (Yurak), Enets (Yenisey), and Nganasan (Tavgi). The South Samoyedic subgroup comprises Selkup and the practically extinct Kamas language. None of these languages was written before 1930, and they are currently used only occasionally for educational purposes in some elementary schools.

Enewetak, atoll, northwestern end of the Ralik chain, Republic of the Marshall Islands, in the western Pacific Ocean. Circular in shape (50 miles [80 km] in circumference), it comprises 40 islets around a lagoon 23 miles (37 km) in diameter. During World War II it was captured from the Japanese by

Ukraine: Literature: In his work Eneyida (1798), he transformed the heroes of Virgil’s Aeneid into Ukrainian Cossacks. Classicist prose appeared only with Hryhorii Kvitka-Osnovianenko’s novel Marusya (1834).

Belle-Île-en-Mer, island off the south coast of Brittany, western France, 8 miles (13 km) southwest of Presqu’Île de Quiberon and administratively part of Morbihan département, Bretagne région. As an outpost of the mainland ports of Saint-Nazaire and Lorient, a citadel on the island was

oratorio: Oratorio after 1750: …oratorio of major importance is L’Enfance du Christ (1854) by Hector Berlioz, a series of theatrical tableaus.

Tahar Ben Jelloun: …until L’Enfant de sable (1985; The Sand Child), an imaginative, richly drawn novel that critiques gender roles in Arab society through the tale of a girl raised as a boy, that Ben Jelloun was accorded widespread praise and recognition. Its sequel, La Nuit sacrée (1987; The Sacred Night), won France’s…

French literature: Romanticism: …terms mal du siècle and enfant du siècle (literally “child of the century”) capture their distress. Alfred de Musset took the latter phrase for his autobiography, La Confession d’un enfant du siècle (1836; The Confession of a Child of the Century). Most French Romantics, whether they adopted a liberal or…

Maurice Ravel: …of his best known opera, L’Enfant et les sortilèges. The latter work gave Ravel an opportunity of doing ingenious and amusing things with the animals and inanimate objects that come to life in this tale of bewitchment and magic in which a naughty child is involved. His only other operatic…

Camara Laye: …autobiographical novel L’Enfant noir (1953; The Dark Child) recreates nostalgically his childhood days in Guinea in a flowing, poetic prose. The life he depicts in a traditional African town is an idyllic one in which human values are paramount and the inevitable alienation from the land that accompanies Western technology…

Dardenne brothers: In 2005, with L’Enfant (The Child), the brothers for the second time in six years won the Palme d’Or. Only filmmakers Emir Kusturica and Imamura Shohei had previously won twice. L’Enfant explores life in a poverty-stricken, gritty, industrial region of French-speaking southern Belgium. Its protagonist, Bruno, is a 20-year-old…

Pierre Charles L’Enfant was a French-born American engineer, architect, and urban designer who designed the basic plan for Washington, D.C., the capital city of the United States. L’Enfant studied art under his father at the Royal Academy of Painting and Sculpture from 1771 until he enlisted in

Barthélemy-Prosper Enfantin was an eccentric French social, political, and economic theorist who was a leading member of the St. Simonian movement. After studies at the École Polytechnique, Enfantin traveled widely and frequented secret societies in Paris. When introduced to the social reformer