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…

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.

Tay-Sachs disease: …low activity of the enzyme hexosaminidase A allows an unusual sphingolipid, ganglioside GM2, to accumulate in the brain, where it soon exerts devastating effects on neurological function. In some affected children, the enzyme is present but the sphingolipid accumulates nonetheless. Tay-Sachs infants appear normal at birth but become listless and…

Philadelphia Flyers: …the presence of star goaltender Ron Hextall, the team’s play fell off in the early 1990s, and the Flyers missed the playoffs each season between 1989–90 and 1993–94. In 1992 the team acquired centre Eric Lindros, who became one of the biggest stars in the NHL in his eight seasons…

historiography: The presentation of history: The American historian Jack Hexter wrote entertainingly about this issue, pointing out that excessive quotation breaks up the flow of the narrative and introduces discordant voices into the text. On the other hand, there are times when a point can be made only with the exact words of…

vitamin C, water-soluble, carbohydrate-like substance that is involved in certain metabolic processes of animals. Although most animals can synthesize vitamin C, it is necessary in the diet of some, including humans and other primates, in order to prevent scurvy, a disease characterized by soreness

antimicrobial agent: Antiseptics and germicides: …creosote, while such 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.,…

hookworm: Infection and treatment: Hexylresorcinol has no serious contraindications, is effective against 80 percent of the worms, and removes 90 percent of A. lumbricoides on a single treatment. Mass treatment, with other anthelminthics, of large groups of heavily infected persons has been successful in reducing the incidence of hookworm,…

Elvis Costello: …traditional pop vocal album; and Hey Clockface (2020). In 2021 he released Spanish Model, a Spanish-language version of This Year’s Model; it featured numerous other artists, including Juanes. Costello also cowrote (with Burnett) the Academy Award-nominated song “The Scarlet Tide” for the 2003 film Cold Mountain.

Neil Young: Harvest, Rust Never Sleeps, and Harvest Moon: …the main character in “Hey Hey, My My.” Thus, Young’s reenergized reaction to punk sharply contrasted with that of his aging peers, who generally felt dismissed or threatened. It also demonstrated how resistant he was to nostalgia—a by-product of his creative restlessness.

Paul McCartney: The Beatles: …as he did with “Hey Jude” (1968). This facility extends to his bass playing, which is famously melodic though often overlooked. A multi-instrumentalist, McCartney also played drums on some Beatles tracks and played all the instruments on some of his solo albums, as well as lead guitar at concerts.

Sarah Polley: She then codirected Hey Lady! (2020– ), a digital comedy series centring on a senior citizen who challenges societal norms and sometimes even the law; each episode was just five minutes long. In 2022 she earned praise for Women Talking, an adaptation of Miriam Toews’s novel, which was…

Douglas Coupland: …novels included Miss Wyoming (1999), Hey Nostradamus! (2003), JPod (2006), The Gum Thief (2007), and Worst. Person. Ever. (2013). In addition, Coupland penned the screenplay for Everything’s Gone Green (2006), and he cocreated and cowrote the TV series jPod (2008), which was based on his 2006 novel. Bit Rot: Stories

oceanic ridge: Pacific Ocean: …spreading centres, the American geophysicist Richard N. Hey developed the idea of the propagating rift. In this phenomenon, one branch of a spreading centre ending in a transform fault lengthens at the expense of the spreading centre across the fault. The rift and fault propagate at one to five times…

Kızıl Adalar: …islands, Büyükada (Prinkipo, ancient Pityoussa), Heybeli Ada (Halki, ancient Chalcitis), Burgaz Adası (Antigoni, ancient Panormos), and Kınalı Ada (Proti). Büyükada was Leon Trotsky’s home for a time after his exile from the Soviet Union in 1929. Heybeli Ada has a branch of the Turkish naval academy.

Shaykh Ḥaydar was one of the founders of the Ṣafavid state (1501–1736) in Iran. Ḥaydar inherited the leadership of the Ṣafavid order, a Shīʿite Muslim movement centred on Ardabīl (now in northwest Iran). He was raised in the city of Amid, but when the Kara Koyunlu empire in western Iran

Jan van der Heyden was a leading painter of cityscapes in late-17th-century Holland, especially known for his views of Amsterdam done in the 1660s. Little is known of his early life, though it is recorded that van der Heyden studied under a Dutch glass painter. In 1650 van der Heyden’s family moved

Reinhard Heydrich was a Nazi German official who was Heinrich Himmler’s chief lieutenant in the Schutzstaffel (“Protective Echelon”), the paramilitary corps commonly known as the SS. He played a key role in organizing the Holocaust during the opening years of World War II. Heydrich’s father, who

Reinhard Heydrich was a Nazi German official who was Heinrich Himmler’s chief lieutenant in the Schutzstaffel (“Protective Echelon”), the paramilitary corps commonly known as the SS. He played a key role in organizing the Holocaust during the opening years of World War II. Heydrich’s father, who

Thor Heyerdahl was a Norwegian ethnologist and adventurer who organized and led the famous Kon-Tiki (1947) and Ra (1969–70) transoceanic scientific expeditions. Both expeditions were intended to prove the possibility of ancient transoceanic contacts between distant civilizations and cultures. For

German literature: Expressionism: Georg Trakl, Georg Heym, and Gottfried Benn created terrifying images of war, urban life, oppression, and illness in their lyric poetry, and, although Trakl expressed a visionary mysticism in his battlefield scenes, Heym and Benn presented reality as grotesque, distorted, and starkly unrelieved. At the same time,…

I. Michael Heyman was an American scholar known for his academic career at the University of California at Berkeley and for spearheading the digitization of the archives of the Smithsonian Institution during his tenure as secretary (CEO). Despite Heyman’s early interest in science—he qualified to

I. Michael Heyman was an American scholar known for his academic career at the University of California at Berkeley and for spearheading the digitization of the archives of the Smithsonian Institution during his tenure as secretary (CEO). Despite Heyman’s early interest in science—he qualified to

Corneille Heymans was a Belgian physiologist who received the Nobel Prize for Physiology or Medicine in 1938 for his discovery of the regulatory effect on respiration of sensory organs associated with the carotid artery in the neck and with the aortic arch leading from the heart. After taking his

Corneille Heymans was a Belgian physiologist who received the Nobel Prize for Physiology or Medicine in 1938 for his discovery of the regulatory effect on respiration of sensory organs associated with the carotid artery in the neck and with the aortic arch leading from the heart. After taking his

Piet Heyn was an admiral and director of the Dutch West India Company who captured a Spanish treasure fleet (1628) with 4,000,000 ducats of gold and silver (12,000,000 gulden, or florins). That great naval and economic victory provided the Dutch Republic with money to continue its struggle against

library: Later developments: The library’s next director, C.G. Heyne, enthusiastically followed the same principles, with the result that Göttingen became the best-organized library in the world.

Jaroslav Heyrovský was a Czech chemist who received the Nobel Prize for Chemistry in 1959 for his discovery and development of polarography. Educated at the Charles University (Universita Karlova) of Prague and at University College, London, Heyrovský worked in London under Sir William Ramsay and

Paul Johann Ludwig von Heyse was a German writer and prominent member of the traditionalist Munich school who received the Nobel Prize for Literature in 1910. Heyse studied classical and Romance languages and traveled for a year in Italy, supported by a research grant. After completing his studies

Heysel Stadium disaster: FC and Juventus at Heysel Stadium in Brussels, Belgium. The disaster was blamed on hooliganism, mistakes by officials, and structural issues with the stadium.

Heysel Stadium disaster, incident in which a crush of football (soccer) fans resulted in 39 deaths and some 600 injuries. It occurred on May 29, 1985, during a match between Liverpool FC and Juventus at Heysel Stadium in Brussels, Belgium. The disaster was blamed on hooliganism, mistakes by

philosophy of mathematics: Logicism, intuitionism, and formalism: …was developed by Brouwer’s student Arend Heyting and somewhat later by the British philosopher Michael Dummett. Brouwer and Heyting endorsed intuitionism in conjunction with psychologism, but Dummett did not, and the view is consistent with various nonpsychologistic views—e.g., Platonism and nominalism.

DuBose Heyward: Dorothy Heyward (1890–1961) attended G.P. Baker’s Workshop 47 at Harvard University and had a play produced on Broadway in 1924. She was most effective as a collaborator with her husband and others.

DuBose Heyward was an American novelist, dramatist, and poet whose first novel, Porgy (1925), was the basis for a highly successful play, an opera, and a motion picture. At the age of 17 Heyward worked on the waterfront, where he observed the black Americans who were to become the subject of his

DuBose Heyward was an American novelist, dramatist, and poet whose first novel, Porgy (1925), was the basis for a highly successful play, an opera, and a motion picture. At the age of 17 Heyward worked on the waterfront, where he observed the black Americans who were to become the subject of his

Jasper Heywood was a Jesuit priest and poet whose translations of the works of the Roman playwright Seneca, including Troades (1559), Thyestes (1560), Hercules furens (1561), and other plays issued as Seneca His Tenne Tragedies Translated into English (1581), influenced English drama. A son of the

John Heywood was a playwright whose short dramatic interludes helped put English drama on the road to the fully developed stage comedy of the Elizabethans. He replaced biblical allegory and the instruction of the morality play with a comedy of contemporary personal types that illustrate everyday

Bo Xilai and Gu Kailai: On November 15, 2011, Neil Heywood, a British businessman who had dealt with Bo and Gu for 15 years, was found dead in a hotel room in Chongqing. The death was immediately ascribed to “excessive alcohol consumption,” but on February 6, 2012, former Chongqing police chief Wang Lijun, whom…

Thomas Heywood was an English actor-playwright whose career spans the peak periods of Elizabethan and Jacobean drama. Heywood apparently attended the University of Cambridge, though his attendance there remains undocumented. After arriving in London sometime before 1598, he joined Philip Henslowe’s

Akshay Kumar: His later films included Heyy Babyy (2007), Singh Is Kinng (2008), OMG: Oh My God! (2012), Toilet: Ek prem katha (2017; “Toilet: A Love Story”), 2.0 (2018), Good Newwz (2019), and Laxmii (2020). He also starred in the popular Housefull series of comedy films (2010, 2012, 2016, and 2019).

Hezbollah, political party and militant group that first emerged during Lebanon’s civil war as a militia after the Israeli invasion of that country in 1982. Since the 2000s it has been one of the foremost political forces in Lebanon. Shiʿi Muslims, traditionally the weakest religious group in

Hezbollah, political party and militant group that first emerged during Lebanon’s civil war as a militia after the Israeli invasion of that country in 1982. Since the 2000s it has been one of the foremost political forces in Lebanon. Shiʿi Muslims, traditionally the weakest religious group in

Hezekiah was the son of Ahaz, and the 13th successor of David as king of Judah at Jerusalem. The dates of his reign are often given as about 715 to about 686 bc, but inconsistencies in biblical and Assyrian cuneiform records have yielded a wide range of possible dates. Hezekiah reigned at a time

Manchu-Tungus languages: Classification and linguistic characteristics: For example, Ho-chen (Hezhe), usually considered a dialect of Nanai, is phonologically similar to the Manchu group, but morphologically similar to the Tungus group. This ambiguity has led some scholars to propose a third branch, the Central group, for Manchu-Tungus languages. Undoubtedly, the patterns of contact with…

Bar Hebraeus: …was an encyclopaedia of philosophy, Ḥēʾwath ḥekkmthā (“The Butter of Wisdom”), in which he commented on every branch of human knowledge in the Aristotelian tradition. Another was his Chronography, consisting of a secular history from the time of creation and an ecclesiastical history of the patriarchate of Antioch and the…

hafnium (Hf), chemical element (atomic number 72), metal of Group 4 (IVb) of the periodic table. It is a ductile metal with a brilliant silvery lustre. The Dutch physicist Dirk Coster and the Hungarian Swedish chemist George Charles von Hevesy discovered (1923) hafnium in Norwegian and Greenland

radar: Over-the-horizon radar: …the shortwave, or high-frequency (HF), portion of the radio band (from 3 to 30 MHz). The advantage of the HF band is that radio waves of these frequencies are refracted (bent) by the ionosphere so that the waves return to the Earth’s surface at long distances beyond the horizon,…

Robert Morris Page: …the first successful demonstration of high-frequency over-the-horizon (HF OTH) radar, whose propagating waves are refracted by the Earth’s ionosphere. The detection of ships, aircraft, and ballistic missiles was thereby extended out to about 3,200 km (2,000 miles), approximately 10 times the range of microwave radars, which are limited to the…

direction finder: …these devices were known as HF/DF, or Huff Duff. The use of HF/DF is given much credit, along with microwave radar and Ultra (a project for decoding encrypted German military messages), for the eventual defeat of the very serious German submarine threat.

hydrofluorocarbon (HFC), any of several organic compounds composed of hydrogen, fluorine, and carbon. HFCs are produced synthetically and are used primarily as refrigerants. They became widely used for this purpose beginning in the late 1980s, with the introduction of the Montreal Protocol, which

food desert: Improving access to healthy foods: Barack Obama proposed the Healthy Food Financing Initiative (HFFI), which encouraged retailers to bring healthy foods to impoverished urban and rural communities. A large share of subsequent funding for HFFI went to community-development financial institutions for lending to food retailers in food deserts.

Habitat for Humanity International (HFHI), Christian ministry that builds and renovates housing for families in need. HFHI was founded in 1976 by American philanthropist Millard Dean Fuller and his wife, Linda Fuller. The group gained wide recognition because of the involvement of former president

metabolic disease: Galactose and fructose disorders: Hereditary fructose intolerance (HFI) is caused by a deficiency of the liver enzyme fructose-1-phosphate aldolase. Symptoms of HFI appear after the ingestion of fructose and thus present later in life than do those of galactosemia. Fructose is present in fruits, table sugar (sucrose), and infant…

Herschel: Herschel discovered a galaxy, HFLS 3, that was forming stars at a rate more than 2,000 times that of the Milky Way even though HFLS 3 was observed only 880 million years after the big bang; accepted theories of galaxy formation could not explain how such a massive and…

Golden Globe Award: …awards presented annually by the Hollywood Foreign Press Association (HFPA) in recognition of outstanding achievement in motion pictures and television during the previous year. Within the entertainment industry, the Golden Globes are considered second in importance both to the Academy Awards (for film) and to the Emmy Awards (for television),…

episome: …(such a cell is designated Hfr). F+ and Hfr cells act as donors during conjugation, a mating process in certain bacteria (e.g., Escherichia, Salmonella, Serratia, Pseudomonas). During conjugation, cells lacking the episome (called F- cells) may receive either the episome (from an F+ cell) or the episome plus the chromosomal…

hantavirus: …first group is known as hemorrhagic fever with renal syndrome (HFRS). These illnesses typically develop within 1 to 2 weeks of exposure (sometimes later) and are characterized by acute fever, severe headache, blurred vision, and nausea. Severe forms, such as those involving Dobrava virus or Hantaan virus, can result in…

hepatitis: Hepatitis F and G: …water are attributed to the hepatitis F virus (HFV), which was first reported in 1994. Another virus isolated in 1996, the hepatitis G virus (HGV), is believed to be responsible for a large number of sexually transmitted and bloodborne cases of hepatitis. HGV causes acute and chronic forms of the…

mercury (Hg), chemical element, liquid metal of Group 12 (IIb, or zinc group) of the periodic table. atomic number80 atomic weight200.592 melting point−38.83 °C (−37.89 °F) boiling point356.62 °C (673.91 °F) specific gravity13.5 at 20 °C (68 °F) valence1, 2 electron configuration2-8-18-32-18-2 or

growth hormone (GH), peptide hormone secreted by the anterior lobe of the pituitary gland. It stimulates the growth of essentially all tissues of the body, including bone. GH is synthesized and secreted by anterior pituitary cells called somatotrophs, which release between one and two milligrams of

coal utilization: Grindability: …is used to calculate the Hardgrove grindability index (HGI). The index is used as a guideline for sizing the grinding equipment in a coal-preparation plant.