Ulises Heureaux was the president of the Dominican Republic who allowed most of his country’s economy to fall under U.S. control. The republic’s fiscal disorder led to American intervention after Heureaux’s assassination. Heureaux received some schooling in a Methodist mission and then joined a

Émile Verhaeren: …intimate Les Heures claires (1896; The Sunlit Hours) is an avowal of his love for his wife; it led to the series of his major works, among which the most outstanding are Les Visages de la vie (1899; “The Faces of Life”), the five-part Toute la Flandre (1904–11; “All of…

heuristic, in cognitive psychology, a process of intuitive judgment, operating under conditions of uncertainty, that rapidly produces a generally adequate, though not ideal or optimal, decision, solution, prediction, or inference. Heuristics function as mental shortcuts that produce serviceable

DENDRAL, an early expert system, developed beginning in 1965 by the artificial intelligence (AI) researcher Edward Feigenbaum and the geneticist Joshua Lederberg, both of Stanford University in California. Heuristic DENDRAL (later shortened to DENDRAL) was a chemical-analysis expert system. The

Jean Renoir: Early years: …one of his father’s models, Andrée Heurschling, a few months after the painter’s death, and went with her to live in Marlotte, a village near Paris in which his father had once painted.

Heusler alloy, any of the first magnetic alloys composed of metals that, in their pure state, are not magnetic. The alloys are named after Fritz Heusler, 19th-century German mining engineer and chemist. Heusler alloys consist of approximately two parts of copper, one of manganese, and one of tin.

Heusler alloy: The alloys are named after Fritz Heusler, 19th-century German mining engineer and chemist. Heusler alloys consist of approximately two parts of copper, one of manganese, and one of tin. The tin may be replaced by aluminum, arsenic, antimony, bismuth, or boron; the copper may be replaced by silver.

Theodor Heuss was a liberal democratic legislator, the first president of West Germany, author, and leader of the Free Democratic Party (Freie Demokratische Partei, FDP). He also helped draft a new constitution for postwar West Germany. After receiving a political science degree from the University

Johanna Spyri was a Swiss writer whose Heidi (2 volumes; 1880–81), a classic of children’s literature, is popular all over the world. Her psychological insight into the child mind, her humor, and her ability to appreciate the joys and sorrows of childhood gave her books appeal and lasting value.

Johannes Benedictus van Heutsz was a Dutch general and governor-general of the Dutch East Indies (1904–09) who conquered the Sumatran kingdom of Aceh (also spelled Acheh, or Atjeh) and brought all of Indonesia directly under Dutch rule. Van Heutsz was sent to Aceh as a subaltern in 1873 and won

hepatitis: Hepatitis E: Discovered in the 1980s, the hepatitis E virus (HEV) is similar to HAV. HEV is transmitted in the same manner as HAV, and it, too, only causes acute infection. However, the effects of infection with HEV are more severe than those caused by HAV, and death is more common. The…

lymph node: …through specialized blood vessels called high endothelial venules (HEVs). HEVs contain a single layer of large endothelial cells that possess surface receptors specific for B and T lymphocytes. As these cells pass through the HEVs, they bind to the receptors and are carried into the paracortex of the lymph node.

Hevajra, in northern Buddhism, a fierce protective deity, the yab-yum (in union with his female consort, Nairatmya) form of the fierce protective deity Heruka. Hevajra is a popular deity in Tibet, where he belongs to the yi-dam (tutelary, or guardian, deity) class. His worship is the subject of the

Sa-skya-pa: …Tibetan the important Tantric work Hevajra Tantra, which remains one of the basic texts of the order. He also transmitted into Tibet from India the teachings of the lam-’bras (“path and result”).

Sa-skya-pa: …Tibetan the important Tantric work Hevajra Tantra, which remains one of the basic texts of the order. He also transmitted into Tibet from India the teachings of the lam-’bras (“path and result”).

rubber tree, (Hevea brasiliensis), South American tropical tree of the spurge family (Euphorbiaceae). Cultivated on plantations in the tropics and subtropics, especially in Southeast Asia and western Africa, it replaced the rubber plant in the early 20th century as the chief source of natural

mask: Social and religious uses: …Guinea build mammoth masks called hevehe, attaining 20 feet (6 metres) in height. They are constructed of a palm wood armature covered in bark cloth; geometric designs are stitched on with painted cane strips. These fantastic human-animal masks are given a frightening aspect. When mask wearers emerge from the men’s…

Johannes Hevelius was an astronomer who compiled an atlas of the Moon (Selenographia, published 1647) containing one of the earliest detailed maps of its surface as well as names for many of its features. A few of his names for lunar mountains (e.g., the Alps) are still in use, and a lunar crater

Hever Castle, castle in Hever, Kent, England, that is best known for being the childhood home of Anne Boleyn, second wife of King Henry VIII. Since the mid-20th century it has been a tourist attraction, based on its connection with the Tudors. The castle is an enjoyable combination of Tudor and

Heves, megye (county), northern Hungary. It is bounded by the counties of Borsod-Abaúj-Zemplén to the north and east, Jász-Nagykun-Szolnok to the south, Pest to the southwest, and Nógrád to the west. The main cities are Eger—the county seat, in the Eger River valley—and the industrial centres of

Georg Charles von Hevesy was a chemist and recipient of the 1943 Nobel Prize for Chemistry. His development of isotopic tracer techniques greatly advanced understanding of the chemical nature of life processes. In 1923 he also discovered, with the Dutch physicist Dirk Coster, the element hafnium.

Georg Charles von Hevesy was a chemist and recipient of the 1943 Nobel Prize for Chemistry. His development of isotopic tracer techniques greatly advanced understanding of the chemical nature of life processes. In 1923 he also discovered, with the Dutch physicist Dirk Coster, the element hafnium.

Hebron, city in the West Bank, situated in the southern Judaean Hills south-southwest of Jerusalem. Located about 3,050 feet (930 metres) above sea level, Hebron long benefited from its mountainous clime, which encouraged the cultivation of fruit trees and vineyards. In addition, its location at a

Dwight D. Eisenhower: First term as president of Dwight D. Eisenhower: …the spring of 1953 the Department of Health, Education, and Welfare was created.

Gordon Hewart, 1st Viscount Hewart was the lord chief justice of England from 1922 to 1940. A scholar of University College, Oxford, Hewart was called to the bar at the Inner Temple in 1902 and practiced on the northern circuit. After an unsuccessful contest for a seat in Parliament in northwest

Gordon Hewart, 1st Viscount Hewart was the lord chief justice of England from 1922 to 1940. A scholar of University College, Oxford, Hewart was called to the bar at the Inner Temple in 1902 and practiced on the northern circuit. After an unsuccessful contest for a seat in Parliament in northwest

Gordon Hewart, 1st Viscount Hewart was the lord chief justice of England from 1922 to 1940. A scholar of University College, Oxford, Hewart was called to the bar at the Inner Temple in 1902 and practiced on the northern circuit. After an unsuccessful contest for a seat in Parliament in northwest

Johannes Hevelius was an astronomer who compiled an atlas of the Moon (Selenographia, published 1647) containing one of the earliest detailed maps of its surface as well as names for many of its features. A few of his names for lunar mountains (e.g., the Alps) are still in use, and a lunar crater

Johannes Hevelius was an astronomer who compiled an atlas of the Moon (Selenographia, published 1647) containing one of the earliest detailed maps of its surface as well as names for many of its features. A few of his names for lunar mountains (e.g., the Alps) are still in use, and a lunar crater

Neoclassical art: Britain: …the Elder, John Deare, and Christopher Hewetson—the last two working mostly in Rome. The leading artist of the younger generation was John Flaxman, professor of sculpture at the Royal Academy and one of the few British artists of the period with an international reputation. The last generation of Neoclassicists included…

Antony Hewish was a British astrophysicist who won the Nobel Prize for Physics in 1974 for his discovery of pulsars (cosmic objects that emit extremely regular pulses of radio waves). Hewish was educated at the University of Cambridge and in 1946 joined the radio astronomy group there led by Sir

Abram Stevens Hewitt was an American industrialist, philanthropist, and politician who in 1886 defeated Henry George and Theodore Roosevelt to become mayor of New York City. Hewitt won a scholarship to Columbia College (now part of Columbia University). He graduated in 1842 and remained at Columbia

The Well-Tempered Clavier, BWV 846–893: Sviatoslav Richter, Angela Hewitt, and András Schiff. A performance by American composer Wendy Carlos of two of the prelude and fugue numbers from Book I is noteworthy for having been played on a Moog synthesizer (Switched-On Bach, 1968). She made other recordings of Baroque music on synthesizer…

Don S. Hewitt was an American television producer who was perhaps best known for creating and producing the television news magazine 60 Minutes. After serving as a war correspondent in World War II, Hewitt joined CBS in 1948, and he directed its first televised evening news broadcast, with Douglas

Don S. Hewitt was an American television producer who was perhaps best known for creating and producing the television news magazine 60 Minutes. After serving as a war correspondent in World War II, Hewitt joined CBS in 1948, and he directed its first televised evening news broadcast, with Douglas

Henry Kent Hewitt was a U.S. naval officer who directed important amphibious landings in Europe during World War II. A graduate of the U.S. Naval Academy at Annapolis, Md., in 1906, Hewitt commanded the destroyer “Cummings” during World War I. When World War II broke out, he was put in charge of

Lleyton Hewitt is an Australian professional tennis player whose astonishing court speed, fierce determination, and unrelenting ground strokes allowed him to capture victories at both the U.S. Open (2001) and Wimbledon (2002). Hewitt was born into an exceedingly athletic family; his father, uncle,

Lleyton Hewitt is an Australian professional tennis player whose astonishing court speed, fierce determination, and unrelenting ground strokes allowed him to capture victories at both the U.S. Open (2001) and Wimbledon (2002). Hewitt was born into an exceedingly athletic family; his father, uncle,

Peter Cooper Hewitt was an American electrical engineer who invented the mercury-vapour lamp, a great advance in electrical lighting. At an early age, Hewitt began research on electricity and mechanics in a greenhouse converted into a workshop. In 1901 he marketed his first mercury-vapour lamp, but

R. Buckminster Fuller: Life: …married Anne Hewlett, daughter of James Monroe Hewlett, a well-known architect and muralist. Hewlett had invented a modular construction system using a compressed fibre block, and after the war Fuller and Hewlett formed a construction company that used this material (later known as Soundex, a Celotex product) in modules for…

Damon Albarn: …1990s Albarn and comic-book artist Jamie Hewlett developed the idea for Gorillaz, a “virtual band” for which animated characters drawn by Hewlett would serve as the sole visual component (on record covers and in music videos, for instance) of music conceived by Albarn. The group’s self-titled full-length debut album (2001)…

William Hewlett was an American engineer and businessman who cofounded the electronics and computer corporation Hewlett-Packard Company (HP). Hewlett’s interest in science and electronics started when he was a child, and in 1930 he began studying engineering at Stanford University in California. It

William Hewlett was an American engineer and businessman who cofounded the electronics and computer corporation Hewlett-Packard Company (HP). Hewlett’s interest in science and electronics started when he was a child, and in 1930 he began studying engineering at Stanford University in California. It

Hewlett-Packard Company, American manufacturer of software and computer services and a major brand in the history of computers and computer-related products. The company split in 2015 into two companies: HP Inc. and Hewlett Packard Enterprise. Headquarters were in Palo Alto, California. The company

Tony Abbott: …secretary for Liberal Party leader John Hewson in 1990. When the Liberals were defeated in 1993 in an election that they were widely expected to win, Hewson became a pariah within the party, and Abbott found himself out of work. From 1993 to 1994 he served as executive director for…

Bono is the lead singer for the popular Irish rock band U2 and a prominent human rights activist. He was born of a Roman Catholic father and a Protestant mother (who died when he was just age 14). In Dublin in 1977, he and school friends David Evans (later “the Edge”), Larry Mullen, Jr., and Adam

William Hewson was a British anatomist and physiologist who described blood coagulation and isolated a key protein in the coagulation process, fibrinogen, which he called coagulable lymph. He also investigated the structure of the lymphatic system and described red blood cells. Hewson was trained

number game: Puzzles involving configurations: …marketed under the name of hex.

hex sign, emblem painted on a barn, especially in Pennsylvania Dutch country, an agricultural region in southeastern Pennsylvania largely settled by German immigrants who have preserved ethnic custom and identification to a high degree (see Pennsylvania German). Hex designs, usually round, with

organometallic compound: The structure of metal carbonyls: …the six carbonyl ligands in hexacarbonylchromium project toward the vertices of an octahedron.

benzene hexachloride (BHC), any of several stereoisomers of 1,2,3,4,5,6-hexachlorocyclohexane formed by the light-induced addition of chlorine to benzene. One of these isomers is an insecticide called lindane, or Gammexane. Benzene hexachloride was first prepared in 1825; the insecticidal

antimicrobial agent: Antiseptics and germicides: …bisphenols as hexyl resorcinol and hexachlorophene are widely used as antiseptic agents in soaps. Chlorine and iodine are both extremely effective agents and can be used in high dilution. Chlorine is widely used in the disinfection of drinking-water supplies, and among its derivatives, the hypochlorite solutions (e.g., Dakin’s solution) are…

hexachloroplatinic acid (H2PtCl6∙6H2O), complex compound formed by dissolving platinum metal in aqua regia (a mixture of nitric and hydrochloric acids) or in hydrochloric acid that contains chlorine. It is crystallized from the solution in the form of reddish brown deliquescent (moisture-absorbing)

hexachord, in music, six-note pattern corresponding to the first six tones of the major scale (as, C–D–E–F–G–A). The names of the degrees of the hexachord are ut, re, mi, fa, sol, and la (also called solmization [q.v.] syllables); they were devised by the 11th-century teacher and theorist Guido of

cnidarian: Annotated classification: Subclass Zoantharia Sea anemones and corals. Six (or multiples of 6) tentacles (rarely branched). Mesenteries commonly arranged hexamerously. Solitary or colonial. Skeletons non-spicular calcareous, horny, or lacking. Usually 2 siphonoglyphs. Order Actiniaria Sea anemones. Solitary or clonal, never colonial; lacking skeleton; with or without basilar muscles.…

glass sponge, any of a class (Hexactinellida, also called Hyalospongiae, or Triaxonia) of sponges characterized by a skeleton that consists of silica spicules (needlelike structures) often united into a delicate geometric network—e.g., that of Venus’s flower basket (q.v.). Glass sponges occur

carboxylic acid: Saturated aliphatic acids: to C18 (lauric, myristic, palmitic, and stearic), are present in the fats and oils of many animals and plants, with palmitic and stearic acids being the most prevalent. Lauric acid (C12) is the main acid in coconut oil (45–50 percent) and palm kernel oil (45–55 percent). Nutmeg butter is…

Blossius Aemilius Dracontius: …Middle Ages under the title Hexaëmeron. The tragedy Orestes—927 lines on the murder of Agamemnon and the revenge of his son, Orestes—has been transmitted without Dracontius’s name but is now held to be his. Dracontius demonstrates wide familiarity with pagan Latin literature and with the Bible.

St. Basil the Great: Works and legacy: In the Hexaëmeron (“Six Days”), nine Lenten sermons on the days of the Creation, Basil speaks of the varied beauty of the world as reflecting the splendour of God. Against Eunomius defends the deity of the Son against an extreme Arian thinker, and On the Holy Spirit…

George the Pisidian: George’s major work, the Hexaëmeron (Greek: “Of Six Days”), a rhapsody on the beauty of creation and the Creator’s wisdom, was popularized through translations into Armenian and Slavic languages. Other writings included the moralistic elegy “De vanitate vitae” (“On the Vanity of Life”), in the manner of the Old…

major industrial polymers: Fluoroelastomers: the monomers vinylidene fluoride (CH2=CF2), hexafluoropropylene (CF2=CFCF3), and chlorotrifluoroethylene (CF2=CFCl) in addition to tetrafluoroethylene. These elastomers have outstanding resistance to oxygen, ozone, heat, and swelling by oils, chlorinated solvents, and fuels. With service temperatures up to 250° C (480° F), they are the elastomers of choice for use in industrial…

hexagon, in geometry, a six-sided polygon. In a regular hexagon, all sides are the same length, and each internal angle is 120 degrees. The area of a regular hexagon is commonly determined with the formula: area = 3√3 2 × side2In an irregular hexagon, the sides are of unequal length, and each

crystal: Structures of metals: , which is called the hexagonal- closest-packed (hcp) structure. Cadmium and zinc crystallize with this structure. The second possibility is to place the atoms of the third layer over those of neither of the first two but instead over the set of holes in the first layer that remains unoccupied.…

basketry: Matting or plaited construction: …one woven) is known as hexagonal openwork and is the technique most common in openwork basketry using flat elements. It has a very wide distribution: from Europe to Japan, southern Asia, Central Africa, and the tropical Americas. A closely woven fabric in three layers, forming a six-pointed star design, is…

hexagonal system, one of the principal categories of structures to which a given crystalline solid can be assigned. Components of crystals in this system are located by reference to four axes—three of equal length set at 120° to one another and a fourth axis perpendicular to the plane of the other

Canadian literature: World War II and the postwar period, 1935–60: …models for the next generation—the Hexagone poets.

Yijing: …its presentation of 64 symbolic hexagrams that, if properly understood and interpreted, are said to contain profound meanings applicable to daily life. Throughout the ages, Yijing enthusiasts have claimed that the book is a means of understanding, and even controlling, future events.

greenling, any of a number of marine fish of the family Hexagrammidae (order Scorpaeniformes). Greenlings are characterized, as a group, by such features as small scales, long dorsal fins, and strong jaw teeth. Members of the family usually do not exceed a length of about 45 or 46 cm (18 inches).

scorpaeniform: Annotated classification: Suborder Hexagrammoidei Moderate-sized, slender-bodied fishes. Vertebrae 42–64; ribs attached to strong parapophyses (projections of vertebrae). Small scales, long dorsal fins, spines on the head few, powerful teeth in jaws. Locally important food fishes, some with sporting value. Size of most Hexagrammidae (greenlings) and Anoplopomatidae (sablefish) to…

greenling: …the North Pacific; and the ainame (H. otakii), a common food fish of Japan.

iron meteorite: …groups grading into one another: hexahedrites, octahedrites, and ataxites. Hexahedrites are usually made up entirely of kamacite and lack the Widmanstätten pattern. Octahedrites contain both kamacite and taenite and constitute the largest group of iron finds. Most ataxites, which are the rarest group, are pure taenite; some ataxite specimens contain…

isomerism: Stereoisomers of more complex molecules: One classic example is hexahelicene, a molecule composed of six benzene rings connected to each other. The molecule coils in the form of a spiral so that the atoms of the last ring do not impinge on the atoms of the first ring. The result is a left- or…

piperazine, anthelmintic drug used in the treatment of intestinal roundworm infection in humans and domestic animals (including poultry) and against pinworm infection in humans. It is administered orally, in repeated doses, usually as the citrate salt. Its action causes worms to be paralyzed and

hexameter, a line of verse containing six feet, usually dactyls (′ ˘ ˘). Dactylic hexameter is the oldest known form of Greek poetry and is the preeminent metre of narrative and didactic poetry in Greek and Latin, in which its position is comparable to that of iambic pentameter in English

cholinergic drug: The latter group includes hexamethonium and trimethaphan. These drugs cause overall paralysis of the autonomic nervous system because they do not distinguish between sympathetic and parasympathetic ganglia and therefore are not specific in their action. They were the first effective agents to reduce high blood pressure (antihypertensive drugs), but…

amine: Occurrence and sources of amines: Some amines—such as hexamethylenediamine, used in the manufacture of nylon-6,6—are made by catalytic addition of hydrogen to nitriles, R≡CN.

diplomonad: …sometimes causes severe diarrhea, and Hexamita meleagridis, the cause of fatal infectious catarrhal enteritis in turkeys.

chondrichthyan: Annotated classification: Family Hexanchidae (cow sharks and 7-gilled sharks) Distinguished by presence of 6 gill slits; teeth of lower jaw strikingly unlike those of upper, the 5 or 6 on either side of the central tooth being about twice as broad as high, their inner edges saw-toothed with…

natural gas: Hydrocarbon content: hexane. In natural gas reservoirs even the heavier hydrocarbons occur for the most part in gaseous form because of the higher pressures. They usually liquefy at the surface (at atmospheric pressure) and are produced separately as natural gas liquids (NGLs), either in field separators or…

fat and oil processing: Processes: …especially the various grades of petroleum benzin (commonly known as petroleum ether, commercial hexane, or heptane). In large-scale operations, solvent extraction is a more economical means of recovering oil than is mechanical pressing. In the United States and increasingly in Europe, there are many instances of simple petroleum benzin extraction…

carboxylic acid: Saturated aliphatic acids: …6-, 8-, and 10-carbon acids: hexanoic (caproic), octanoic (caprylic), and decanoic (capric) acids, respectively. Common names for these three acids are derived from the Latin caper, meaning “goat.” Some hard cheeses (e.g., Swiss cheese) contain natural propanoic acid. The higher even-numbered saturated acids, from C12 to C18 (lauric,

Hexapla, (Greek: “Sixfold”), edition of the Old Testament compiled by Origen of Alexandria in Caesarea, Palestine, before ad 245. The Hexapla presented for comparison the Hebrew text of the Old Testament, the Hebrew text in Greek characters, and the Greek versions of Aquila, Symmachus, the

Poaceae: Economic and ecological importance: …fusion of diploid gametes); and hexaploid (2n = 21). An example of a domesticated diploid wheat is einkorn wheat (Triticum monococcum), one of the earliest domesticated wheat species. Hybridization of a diploid wheat with Aegilops speltoides (a closely allied species of grass), followed by doubling of the chromosome complement, produced…

hippopotamus: Pygmy hippopotamus: The rare pygmy hippopotamus (Hexaprotodon liberiensis, also known as Choeropsis liberiensis), the other living species of the family Hippopotamidae, is about the size of a domestic pig. The pygmy hippo is less aquatic than its larger relative, although, when pursued, it hides in water. Less gregarious, it…

spider: Annotated classification: Family Hexathelidae 85 mostly tropical species. Arched, glabrous carapace differentiates it from Dipluridae; funnel-web spiders (genus Atrax) of southeastern Australia are venomous. Family Atypidae (purse-web spiders) 43 species of Europe, North America, Japan, Myanmar, and Java. 3 tarsal claws; 6

organosulfur compound: Reactions: …etherlike structures, such as the hexathia-18-crown-6. Oxidation of sulfides yields sulfoxides or, under more vigorous conditions, sulfones; reaction with alkyl halides gives sulfonium salts; and reaction with halogen compounds produces halosulfonium salts. Halosulfonium ions and related species formed from sulfoxides are key intermediates in the synthesis of polysaccharides from

liquid crystal: Symmetries of liquid crystals: … layers, is broken in the hexatic-B phase, but a proliferation of dislocations maintains continuous translational symmetry within its layers. A similar relationship holds between smectic-C and smectic-F. Crystal-B and crystal-G have molecular positions on regular crystal lattice sites, with long axes of molecules (directors) aligned, but allow rotation of molecules…

hexatonic scale, musical scale containing six different tones within an octave. Using the syllables ut, re, me, fa, sol, and la to refer to the pitches, the 11th-century Italian theorist Guido d’Arezzo identified three hexatonic scales—which he called hexachords—built of whole- and half-step

stingray: …1981 with the identification of Hexatrygon bickelli. The specimen, found on the coast of South Africa, showed unique adaptations to deepwater life and was classified by its discoverers in a separate family and suborder.

chondrichthyan: Annotated classification: Family Hexatrygonidae (sixgill stingrays) Distinguished by having 6 pairs of gill slits. 1 genus (Hexatrygon), about 4 species; generally found in very deep water in Indo–West Pacific region but also on the continental shelf. Family Dasyatidae (whip-tailed rays) Caudal fin lacking; no distinct

Ilse Koch was the German wife of a commandant (1937–41) of Buchenwald concentration camp, notorious for her perversion and cruelty. On May 29, 1937, she married Karl Otto Koch, a colonel in the SS who was commander of the Sachsenhausen camp. In the summer of 1937 he was transferred to Buchenwald,

witches’-broom, symptom of plant disease that occurs as an abnormal brushlike cluster of dwarfed weak shoots arising at or near the same point; twigs and branches of woody plants may die back. There are numerous causes, including rust (Gymnosporangium and Pucciniastrum); Apiosporina, Exobasidium,

blitzkrieg: Blitzkrieg in practice: …to be known as the Hexenkessel (“witches’ cauldron”). By the end of the war, Germany found itself defeated by the strategic (Schwerpunkt) and tactical (Kesselschlacht) concepts that had initially brought it such success. German armies were destroyed at Falaise in France, the Scheldt in the Netherlands, and the Bulge in…

Hexham, town, administrative and historic county of Northumberland, northern England. It is situated on the upper River Tyne, about 12 miles (19 km) southeast of Hadrian’s Wall. The abbey church of St. Andrew, containing a great stone staircase, dominates the town. The church and monastery were

Gansu: Agriculture: The fertile Hexi Corridor produces most of the province’s food crops, which include wheat, barley, millet, corn (maize), and tubers. The province is also a modest producer of sugar beets, rapeseed, soybeans, and a variety of fruits. Attempts have been made to increase agricultural output by transforming…

Jiaxing, city, northern Zhejiang sheng (province), eastern China. Jiaxing is a communications centre in the southern Yangtze River (Chang Jiang) delta, situated to the southeast of Lake Tai on the Grand Canal, north of the port of Hangzhou and on the railway between Hangzhou and Shanghai. It is

RDX, powerful explosive, discovered by Georg Friedrich Henning of Germany and patented in 1898 but not used until World War II, when most of the warring powers introduced it. Relatively safe and inexpensive to manufacture, RDX was produced on a large scale in the United States by a secret process

metabolism: Glycolysis: In most cells a hexokinase with a high affinity for glucose—i.e., only small amounts of glucose are necessary for enzymatic activity—effects the reaction. In addition, the liver contains a glucokinase, which requires a much greater concentration of glucose before it reacts. Glucokinase functions only in emergencies, when the concentration…

number game: Polyominoes: …there are 35 types of hexominoes and 108 types of heptominoes, if the dubious heptomino with an interior “hole” is included.

aging: Changes in structural tissues: …a measure of this, the hexosamine–collagen ratio, has been investigated as an index of individual differences in the rate of aging. An important consequence of these changes is decreased permeability of the tissues to dissolved nutrients, hormones, and antibody molecules.