angiosperm: Dermal tissue: , saltbush, Atriplex vesicaria; Amaranthaceae) that prevent a toxic internal accumulation of salt. In other cases, trichomes help prevent predation by insects, and many plants produce secretory (glandular) or stinging hairs (e.g., stinging nettle, Urtica dioica; Urticaceae) for chemical defense against herbivores. In insectivorous plants, trichomes have

atrium, in vertebrates and the higher invertebrates, heart chamber that receives blood into the heart and drives it into a ventricle, or chamber, for pumping blood away from the heart. Fishes have one atrium; amphibians, reptiles, birds, and mammals, two. In humans the atria are the two upper

atrium, in architecture, an open central court originally of a Roman house and later of a Christian basilica. In domestic and commercial architecture, the concept of the atrium experienced a revival in the 20th century. In Roman times the hearth was situated in the atrium. With the developing

reptile: Hearing: …typically made up of a tympanum, a thin membrane located at the rear of the head; the stapes, a small bone running between the tympanum and the skull in the tympanic cavity (the middle ear); the inner ear; and a eustachian tube connecting the middle ear with the mouth cavity.…

Esther Boise Van Deman: …published her preliminary findings in The Atrium Vestae (1909). Van Deman extended her research to other kinds of concrete and brick constructions and published “Methods of Determining the Date of Roman Concrete Monuments” in The American Journal of Archaeology in 1912. Her basic methodology, with few modifications, became standard procedure…

Michael Moorcock: Ballard that later appeared in The Atrocity Exhibition (1970); Thomas Disch’s Camp Concentration (1968), about an American military camp where political prisoners are subjected to experiments to increase their intelligence; and Brian Aldiss’s Barefoot in the Head (1969), about the aftermath of a war in which Europe had been bombarded…

belladonna, (Atropa belladonna), tall bushy herb of the nightshade family (Solanaceae), the source of the crude drug of the same name. The highly poisonous plant is a native of wooded or waste areas in central and southern Eurasia. It grows to about 1.5 metres (4–5 feet) tall and has dull green

Azerbaijan, geographic region that comprises the extreme northwestern portion of Iran. It is bounded on the north by the Aras River, which separates it from independent Azerbaijan and Armenia; on the east by the Iranian region of Gīlān and the Caspian Sea; on the south by the Iranian regions of

Media: …the north was left to Atropates, a former general of Darius III, who succeeded in founding an independent kingdom, named Atropatene, with its capital at Gazaca. In later times Atropatene came under the control of Parthia, Armenia, and Rome.

digestive system disease: Mouth and oral cavity: A bald tongue (atrophic glossitis), with a smooth surface due to complete atrophy of the papillae, is associated with malnutrition, severe iron deficiency anemia, pernicious anemia, and pellagra, a disorder of skin and mucous membranes due to niacin deficiency. The condition is endemic in underdeveloped countries in which…

vaginitis: Atrophic vaginitis occurs in postmenopausal women because the lack of estrogen stimulation causes the surface membrane of the vagina to become thin, dry, and fragile, increasing the likelihood of infection. Hormone replacement therapy restores the protective surface and eliminates vaginitis.

atrophy, decrease in size of a body part, cell, organ, or other tissue. The term implies that the atrophied part was of a size normal for the individual, considering age and circumstance, prior to the diminution. In atrophy of an organ or body part, there may be a reduction in the number or in the

atropine, poisonous crystalline substance belonging to a class of compounds known as alkaloids and used in medicine. Atropine occurs naturally in belladonna (Atropa belladonna), from which the crystalline compound was first prepared in 1831. Since then, a number of synthetic and semisynthetic

Atropos, in Greek mythology, one of the three Fates, the others being Clotho and Lachesis. Atropos’s name (meaning “unalterable” or “inflexible”) indicates her function, that of rendering the decisions of her sisters irreversible or immutable. Atropos is most frequently represented with scales, a

Atryn, trade name of recombinant human antithrombin, an anticoagulant agent used to prevent thrombosis—the formation of a clot in a blood vessel that may block or impede the flow of blood, causing a potentially life-threatening condition. Atryn was developed by U.S.-based GTC Biotherapeutics and

Atrypa, genus of extinct brachiopods, or lamp shells, that has a broad time range and occurs abundantly as fossils in marine rocks from the Silurian through the Early Carboniferous (444 million to 318 million years ago). Many species of Atrypa have been described. The genus is easily recognized by

Air Transportation Stabilization Board (ATSB), U.S. governmental entity created in the aftermath of the attacks of September 11, 2001, to maintain and provide for safe and efficient commercial aviation. The board was created by the Air Transportation Safety and System Stabilization Act, which was

Alalakh, ancient Syrian city in the Orontes (Asi) valley, southern Turkey. Excavations (1936–49) by Sir Leonard Woolley uncovered numerous impressive buildings, including a massive structure known as the palace of Yarim-Lim, dating from c. 1780 bce, when Alalakh was the chief city of the district

Atsina, North American Indian tribe related to the Algonquian-speaking Arapaho, from which they may have separated as early as 1700. The variant name Gros Ventres (French: “Big Bellies”) was a misinterpretation by French trappers of Plains Indian sign language. The Blackfoot called the Atsina the

Iran: The Khwārezm-Shahs: Atsiz was the military leader who, after Sultan Sanjar’s capture in 1153, succeeded in supplanting Seljuq power in northeastern Iran. His ancestor, Anūṣtegin, had been keeper of Malik-Shah’s kitchen utensils and had been rewarded with the governorship of Khwārezm on the Oxus, where he founded…

raden: Atsugai-hō, a technique using thick shell, consists of two methods, one of which is inlay: the shell is inserted into the incised pattern after the surface has been given a first coat of lacquer; after a final coating, the surface is smoothed by burnishing. The…

Atsugi, city, central Kanagawa ken (prefecture), east-central Honshu, Japan. It lies in the Sagami River valley, at the confluence of the Sagami and Nakatsu rivers. Until the late 19th century, Atsugi flourished as a river port, post town, and centre for sericulture. Now an important commercial

Daigo was the 60th emperor of Japan. He was unsuccessful in continuing his father’s policy of limiting the power of the important Fujiwara family, which dominated the Japanese government from 857 to 1160. The son of the emperor Uda, he ascended the throne in 897 and assumed the reign name Daigo;

Atsumi Kiyoshi was a Japanese comic actor who portrayed the bumbling hero Tora-jiro Kuruma (widely known as Tora-san) in the 48-film series Otoko wa tsurai yo (“It’s Tough Being a Man”). The series ran from 1968 to 1996 and was the longest-running film series in which the same actor portrayed the

Kaibara Ekken was a neo-Confucian philosopher, travel writer, and pioneer botanist of the early Tokugawa period (1603–1867) who explicated the Confucian doctrines in simple language that could be understood by Japanese of all classes. He was the first to apply Confucian ethics to women and children

Atsuta, ku (ward), Nagoya city, eastern Aichi ken (prefecture), central Honshu, Japan. It constitutes the south-central part of the city. Atsuta was a port town and early religious centre. In the Edo (Tokugawa) period (1603–1867) it was one of the most-prosperous post towns on the Tōkaidō (“Eastern

Nagoya: The Atsuta Shrine and the nearby Grand Shrine of Ise are the oldest and most highly esteemed Shintō shrines in Japan. Other institutions include Citizen Hall, Aichi Cultural Centre, Chūnichi Hall, and Misono Theatre. Higashiyama Park is noted for its zoological and botanical gardens. Pop. (2005)…

Amadou Toumani Touré was a Malian politician and military leader who twice led his country. He served as interim president (1991–92) after a coup and was elected president in 2002. In March 2012 he was deposed in a military coup. He officially resigned the next month. Touré studied to be a teacher

cereal processing: Human food: …mills into a meal called atta. This meal is cooked into flat cakes known as chapatis.

leafcutter ant: Nests of the Atta genus are characterized by ants of different sizes corresponding to castes of workers, soldiers, reproductives, and “guards.” Deep within the nest, the ants physically and chemically cultivate subterranean “gardens” of fungus that grow on the chewed leaves. The ants remove contaminants and produce amino…

leafcutter ant: …accomplish similar feats: one species, A. capiguara, reduces the commercial value of pasture land in Brazil and Paraguay by as much as 10 percent.

leafcutter ant: …study site in Costa Rica, A. cephalotes attacked only 17 of 332 available plant species, selecting woody species over herbaceous ones and introduced species over natives. Members of the plant families Compositae, Solanaceae, and Euphorbiaceae are frequently attacked. Within the favoured species, the ants prefer freshly sprouted leaves, flowers, and…

leafcutter ant: …cubic feet), a colony of A. sexdens leafcutters may turn over 40,000 kg (88,000 pounds) of soil in tropical moist forests, stimulating root growth of many plant species. In New World tropical rainforests, the large nests of these ants are often found among large trees that are spaced far apart…

Heinrich Heine: Later life and works: Ein Sommernachtstraum (1843–45; Atta Troll, a Midsummer Night’s Dream), a comic spoof of radical pomposity and the clumsiness of contemporary political verse.

Heinrich Heine: Later life and works: Ein Sommernachtstraum (1843–45; Atta Troll, a Midsummer Night’s Dream), a comic spoof of radical pomposity and the clumsiness of contemporary political verse.

Mohammed Atta was an Egyptian militant Islamist and al-Qaeda operative who helped plot and lead the September 11 attacks. He led the team of hijackers who took control of American Airlines flight 11 and flew it into the north tower of New York City’s World Trade Center. Atta studied architecture

antiglobalization: The antiglobalization movement: …most well-known antiglobalization group is ATTAC (Association pour la Taxation des Transactions Financière et l’Aide aux Citoyens, “Association for the Taxation of Financial Transactions and Aid to Citizens”), which exists in more than 30 countries. ATTAC holds that financial globalization leads to a less secure and a less equal playing…

Horn Concerto No. 1 in E-flat Major: …a musical technique known as attacca. Although concerti typically began with the orchestra stating the main themes and the soloist entering later on, Strauss took the opposite approach: after a single strong chord for the orchestra, the soloist begins a heroic theme based on rising and falling arpeggios. The movement…

diplomacy: The United Nations and the changing world order: …came from other agencies as attachés or counselors. Disarmament negotiations, for example, required specialized knowledge beyond the scope of military attachés. Environmental abuse gave rise to a host of topics, such as the law of the sea, global warming, and means of preventing or abating pollution. The complexity of diplomatic…

Western architecture: The Archaic period (c. 750–500 bce): …not freestanding but were half-columns engaged against (that is, partially attached to) a continuous solid wall. An earlier Sicilian variant of this use of the plastically molded wall mass with the orders applied decoratively can be seen in the columnar curtain walls of Temple F at Selinus, begun about 560…

attachment, in U.S. law, a writ issuing from a court of law to seize the person or property of a defendant. In several of the older states in the United States, attachments against property are issued at the commencement of suits in order to secure any judgment that may be entered for the

attachment theory, in developmental psychology, the theory that humans are born with a need to form a close emotional bond with a caregiver and that such a bond will develop during the first six months of a child’s life if the caregiver is appropriately responsive. Developed by the British

envelope: attack, sustain, and decay of a sound. Attack transients consist of changes occurring before the sound reaches its steady-state intensity. Sustain refers to the steady state of a sound at its maximum intensity, and decay is the rate at which it fades to silence. In…

aggressive behaviour: Physiological causes of aggression: …cause or motivation of an attack by one animal on another lies in the attacker’s response to certain cues or stimuli. Such cues can be visual (robins will vigorously attack a bunch of red feathers placed in their territory), auditory (robins will also attack a tape recorder playing the song…

attack aircraft, type of military aircraft that supports ground troops by making strafing and low-level bombing attacks on enemy ground forces, tanks and other armored vehicles, and installations. Attack aircraft are typically slower and less maneuverable than air combat fighters but carry a large

attack rate, in epidemiology, the proportion of people who become ill with (or who die from) a disease in a population initially free of the disease. The term attack rate is sometimes used interchangeably with the term incidence proportion. Attack rates typically are used in the investigation of

submarine: The nuclear navies: …revolution in antisubmarine warfare, with attack submarines becoming the primary antisubmarine weapons. Attack submarines are armed with torpedoes and, in some cases, with antiship missiles. Strategic submarines may carry similar weapons, but their primary weapons are submarine-launched ballistic missiles (SLBMs), such as the U.S. and British Trident.

sound: Other effects on tone: Attack transients, such as the way in which a string is bowed, a trumpet tongued, or a piano key struck, and decay transients, such as the way the sound of a plucked string dies away, are very important in many instruments, particularly those that are…

Attack!, American war film, released in 1956, that was considered groundbreaking for its exploration of cowardice and nepotism in the U.S. military. The film, set in the European theater during World War II, follows an American platoon that must contend with both a superior German force and the

airplane: Aerodynamics: , its angle relative to the wind. Both lift and angle of attack can be immediately, if crudely, demonstrated, by holding one’s hand out the window of a moving automobile. When the hand is turned flat to the wind, much resistance is felt and little “lift” is…

saturniid moth: Major species: …silk-producing species is the large atlas moth (Attacus atlas), whose wingspread often exceeds 25 cm (10 inches). The caterpillar of the cynthia moth (Samia cynthia or walkeri), also known as the ailanthus silk moth, native to Asia and introduced into North America, feeds chiefly on leaves of the ailanthus tree…

Pierre Attaingnant was a prominent French music printer and publisher in the Renaissance who was one of the earliest to use single-impression printing. (Earlier printers printed the staff and the notes in separate impressions.) Before 1527 Attaingnant began using a newly invented movable music

attainder, in English law, the extinction of civil and political rights resulting from a sentence of death or outlawry after a conviction of treason or a felony. The most important consequences of attainder were forfeiture and corruption of blood. For treason, an offender’s lands were forfeited to

attainder, in English law, the extinction of civil and political rights resulting from a sentence of death or outlawry after a conviction of treason or a felony. The most important consequences of attainder were forfeiture and corruption of blood. For treason, an offender’s lands were forfeited to

Pierre Attaingnant was a prominent French music printer and publisher in the Renaissance who was one of the earliest to use single-impression printing. (Earlier printers printed the staff and the notes in separate impressions.) Before 1527 Attaingnant began using a newly invented movable music

sociology: Social stratification: …stratification was influenced by the attainment model of stratification, initiated at the University of Wisconsin by William H. Sewell. Designed to measure how individuals attain occupational status, this approach assigned each occupation a socioeconomic score and then measured the distance between sons’ and fathers’ scores, also using the educational achievement…

palm: Economic importance: …palm, Astrocaryum; the piassava palm, Attalea; the carnauba wax palm, Copernicia; Euterpe; Mauritia; and the babassu palm) was more than $100 million. Entrepreneurs recognized during the 1980s that several genera that have been utilized only from natural stands might be enhanced by the selection, cultivation, and mechanical harvesting that could…

cohune oil: …fruits, or nuts, of the cohune palm tree, Attalea cohune. The tree grows in western Central America from the Yucatán Peninsula to Honduras. The oil’s properties, similar to those of coconut oil, have given it increasing importance. Because the nuts are unusually hard and difficult to crack and their collection…

babassu palm, (Attalea martiana, A. oleifera, or A. speciosa), tall palm tree with feathery leaves that grows wild in tropical northeastern Brazil. The kernels of its hard-shelled nuts are the source of babassu oil, similar in properties and uses to coconut oil and used increasingly as a substitute

babassu palm, (Attalea martiana, A. oleifera, or A. speciosa), tall palm tree with feathery leaves that grows wild in tropical northeastern Brazil. The kernels of its hard-shelled nuts are the source of babassu oil, similar in properties and uses to coconut oil and used increasingly as a substitute

babassu palm, (Attalea martiana, A. oleifera, or A. speciosa), tall palm tree with feathery leaves that grows wild in tropical northeastern Brazil. The kernels of its hard-shelled nuts are the source of babassu oil, similar in properties and uses to coconut oil and used increasingly as a substitute

Antalya, city and Mediterranean Sea port, southwestern Turkey. It is situated on the Gulf of Antalya. Attalia was founded as a seaport in the 2nd century bce by Attalus II Philadelphus, a king of Pergamum. It was bequeathed to the Romans by his successor, Attalus III Philometor Euergetes. St. Paul

Antalya, city and Mediterranean Sea port, southwestern Turkey. It is situated on the Gulf of Antalya. Attalia was founded as a seaport in the 2nd century bce by Attalus II Philadelphus, a king of Pergamum. It was bequeathed to the Romans by his successor, Attalus III Philometor Euergetes. St. Paul

Pergamum: The original Attalid territory around Pergamum (Mysia) was greatly expanded by 188 bce with the addition of Lydia (excluding most Greek coastal cities), part of Phrygia, Lycaonia, and Pisidia (from 183 bce), all former Seleucid territories. This expansion was accomplished as the result of Eumenes II’s alliance…

Attalus I Soter (“Preserver”) was the ruler of Pergamum from 241 to 197 bc, with the title of king after about 230. He succeeded his uncle, Eumenes I (reigned 263–241), and by military and diplomatic skill created a powerful Pergamene kingdom. Attalus’ mother, Antiochis, was a princess of the

Attalus II Philadelphus (“Brotherly”) was the king of Pergamum, in northwest Anatolia, from 159 bc until his death. He was the second son of King Attalus I Soter (reigned 241–197) and brother of Eumenes II (reigned 197–159), whom he succeeded. Before his accession he had been a loyal assistant to

Attalus III Philometor Euergetes (“Loving-his-mother Benefactor”) was the king of Pergamum from 138 to 133 bc who, by bequeathing his domains to Rome, ended the history of Pergamum as an independent political entity. He was the son of Eumenes II (reigned 197–159) and nephew of Attalus II

Priscus Attalus was a usurping Roman emperor of the West in ad 409–410, the first to be raised to that office by barbarians. Attalus was born a pagan and was baptized by an Arian bishop. He was a senator at the time of Alaric’s second siege of Rome, and he was named emperor of the West by the Goths

Afghanistan: The arts and cultural institutions: The performance of the attan dance in the open air has long been a feature of Afghan life. It became the national dance of the Pashtun and then of the entire country. Under the Taliban regime, however, all performances of music and dance—and even listening to or watching the…

orthopteran: General features: …orthopterans: tiny flightless cockroaches (Attaphila), living as commensals in the nests of ants, are only two millimetres long when mature, whereas a species of Megaloblatta found in South America reaches 10 centimetres in length with a wing span of almost 19 centimetres.

palygorskite: Attapulgite is a variety of palygorskite found in Attapulgus, Ga. For chemical formula and physical properties of attapulgite, see clay minerals (table).

attar of roses, fragrant, colourless or pale-yellow liquid essential oil distilled from fresh petals of Rosa damascena and R. gallica and other species of the rose family Rosaceae. Rose oils are a valuable ingredient of fine perfumes and liqueurs. They are also used for flavouring lozenges and

Farīd al-Dīn ʿAṭṭār was a Persian Muslim poet who was one of the greatest Sufi (mystical) writers and thinkers, composing at least 45,000 distichs (couplets) and many brilliant prose works. As a young man Farīd al-Dīn traveled widely, visiting Egypt, Syria, Arabia, India, and Central Asia. He

Yemen: Two Yemeni states: …by ʿAlī Sālim al-Bayḍ and Ḥaydar Abū Bakr al-ʿAṭṭas. It was this element of the YSP that undertook the negotiations that brought about the unity of the two Yemens. The ability of the new leadership to build popular political support and to revive the faltering development of South Yemen was…

Attawapiskat River, river in northern Ontario, Canada, that issues from Attawapiskat Lake (elevation 815 feet [248 metres]) and flows eastward into James Bay, opposite Akimiski Island. For most of its 465-miles (748-km) course, the river is sluggish and navigable only for canoes. Its lower reaches

Athis-Mons, town, southern suburb of Paris, in Essonne département, Île-de-France région, northern France. Athis-Mons lies near the confluence of the Orge and Seine rivers and is bisected by the N7 road artery leading to the centre of Paris. It was ancient Attegais, later Athis-sur-Orge, where a

leaf-rolling weevil, (family Attelabidae), any member of a subgroup of the weevil family, Curculionidae (insect order Coleoptera) whose females protect newly laid eggs by rolling them up inside a growing leaf. After hatching, the larvae eat the leaf from within. Adults are generally small (3–6 mm

Abe Attell was an American professional boxer, undisputed world featherweight champion from 1906 through 1912. Attell was from a poor Jewish family and began his boxing career at 15 as a means of supplementing the family’s income. (Read Gene Tunney’s 1929 Britannica essay on boxing.) In his first

criminal law: Attempt: In Anglo-American law there is a class of offenses known as inchoate, or preliminary, crimes because guilt attaches even though the criminal purpose of the parties may not have been achieved. Thus, the offense of incitement or solicitation consists of urging or requesting another…

Edmond Malone: Malone’s “An Attempt to Ascertain the Order in Which the Plays of Shakespeare Were Written” (1778) was the first such chronology. His three supplemental volumes (1780–83) to scholar George Steevens’s edition of Johnson’s Shakespeare—containing apocryphal plays, textual emendations, and the first critical edition of the sonnets—are…

Dmitri Mendeleev: Other scientific achievements of Dmitri Mendeleev: …khimicheskogo ponimania mirovogo efira (1902; An Attempt Towards a Chemical Conception of the Ether), he explained these phenomena as movements of ether around heavy atoms, and he tried to classify ether as a chemical element above the group of inert gases (or noble gases). This bold (and ultimately discredited) hypothesis…

Marc Maron: …of WTF and Maron’s memoir, Attempting Normal (2013), broadened the audience for his stand-up shows. The comedy TV show Maron, which aired in 2013–16 on IFC (the Independent Film Channel), featured Maron as himself. He also appeared in Easy (2016–19), an anthology series about Chicagoans dealing with everyday issues, and…

10 Organisms Named for David Attenborough: A genus of plesiosaur: • What: small, hardy hawkweed, the only living species from the British Isles to be named after David Attenborough. The plant blooms briefly in the summer, sprinkling the remote and

10 Organisms Named for David Attenborough: Attenborough’s flat lizard: • What: species of lizard that lives in rocky outcroppings. Flat lizards are the only lizards endemic to Africa and are so named for their flat bodies, which allow them to hide in tight crevasses for protection against the heat and predators.…

10 Organisms Named for David Attenborough: Attenborough’s hawkweed: • What: small, hardy hawkweed, the only living species from the British Isles to be named after David Attenborough. The plant blooms briefly in the summer, sprinkling the remote and rocky landscape with cheery yellow blooms. It is considered an endangered species.

10 Organisms Named for David Attenborough: Attenborough’s killifish: • What: small colorful killifish that inhabits ephemeral freshwater pools and marshes formed during the wet season. The fry grow rapidly, mate, and lay their eggs in the muddy substrate; the adults die as the pools dry out. The eggs hatch during the…

10 Organisms Named for David Attenborough: Attenborough’s pintail: • What: striking blue and black dragonfly with intricately veined wings. An agile flier, the insect is common in rice paddies and near bodies of fresh water in its native range.

Nepenthes: Major species: species, the critically endangered Attenborough’s pitcher plant (N. attenboroughii), is the largest carnivorous plant, reaching up to 1.5 metres (4.9 feet) tall. Its pitchers are 30 cm (11.8 inches) in diameter and are able to capture and digest rodents and other small animals. About 25 other species are listed…

10 Organisms Named for David Attenborough: Attenborough’s rubber frog: • What: tiny frog with a short snout, the first amphibian named for Attenborough. The species is terrestrial-breeding, meaning the young do not develop from tadpoles.

David Attenborough is an English broadcaster, writer, and naturalist noted for his innovative educational television programs, especially the nine-part Life series. Attenborough grew up in Leicester, England, where his father was principal of the local university; his older brother, Richard

Richard Attenborough was an English actor, director, and producer known for his dynamic on-screen presence, nuanced work behind the camera, and charity efforts. Attenborough—the eldest of three brothers, one of whom was nature documentarian Sir David Attenborough—was raised in Leicester, England,

Richard Attenborough was an English actor, director, and producer known for his dynamic on-screen presence, nuanced work behind the camera, and charity efforts. Attenborough—the eldest of three brothers, one of whom was nature documentarian Sir David Attenborough—was raised in Leicester, England,

Richard Attenborough was an English actor, director, and producer known for his dynamic on-screen presence, nuanced work behind the camera, and charity efforts. Attenborough—the eldest of three brothers, one of whom was nature documentarian Sir David Attenborough—was raised in Leicester, England,

David Attenborough is an English broadcaster, writer, and naturalist noted for his innovative educational television programs, especially the nine-part Life series. Attenborough grew up in Leicester, England, where his father was principal of the local university; his older brother, Richard

10 Organisms Named for David Attenborough: Burgundy snail: •What: small land snail, less than 40 mm (1.6 inches) in length. Brilliantly colored in speckled red and bright green, the animal is considered a semi-slug because its thin, brittle shell is too small for its body to retract inside.

telephone: The telephone network: …continuously (a process known as attending), responds with a dial tone. Upon receiving the dial tone, the customer enters the called party’s telephone number. The central office stores the entered number, translates the number into an equipment location and a path to that location, and tests whether the called party’s…

Muzio Attendolo Sforza was a soldier of fortune who played an important role in the wars of his period and whose son Francesco became duke of Milan. The son of Giovanni Attendolo, a prosperous farmer of the Romagna (in north-central Italy), Muzio left home in 1384 to join a mercenary band,

attention, in psychology, the concentration of awareness on some phenomenon to the exclusion of other stimuli. Attention is awareness of the here and now in a focal and perceptive way. For early psychologists, such as Edward Bradford Titchener, attention determined the content of consciousness and

attention-deficit/hyperactivity disorder (ADHD), a behavioral syndrome characterized by inattention and distractibility, restlessness, inability to sit still, and difficulty concentrating on one thing for any period of time. Attention-deficit/hyperactivity disorder (ADHD) most commonly occurs in

mental disorder: Attention-deficit disorders: Children with attention-deficit/hyperactivity disorder show a degree of inattention and impulsiveness that is markedly inappropriate for their stage of development. Gross overactivity in children can have many causes, including anxiety, conduct disorder (discussed below), or the stresses associated with living in institutions. Learning…