• 0-9
  • a
  • b
  • c
  • d
  • e
  • f
  • g
  • h
  • i
  • j
  • k
  • l
  • m
  • n
  • o
  • p
  • q
  • r
  • s
  • t
  • u
  • v
  • w
  • x
  • y
  • z
  • Helmund River (river, Central Asia)

    Helmand River, river in southwestern Afghanistan and eastern Iran, about 715 miles (1,150 km) long. Rising in the Bābā Range in east-central Afghanistan, it flows southwestward across more than half the length of Afghanistan before flowing northward for a short distance through Iranian territory

  • Helmuth Karl Bernhard, Count von Moltke (German general [1800–1891])

    Helmuth von Moltke, chief of the Prussian and German General Staff (1858–88) and the architect of the victories over Denmark (1864), Austria (1866), and France (1871). Moltke’s father, a man of unstable character, belonged to the nobility of Mecklenburg, his mother to an old family of the free city

  • Helnaes Stone (monument, Denmark)

    Helnaes Stone, runic monument found at Fyn, Den., in 1860; it is among the oldest inscriptions with so-called Danish runes and is the first Danish example of a stone with the memorial formula: “[Person’s name] raised this stone in memory of.” The monument measures about 6 feet 10 inches (2 m) in

  • helobial endosperm (plant anatomy)

    angiosperm: Fertilization and embryogenesis: In helobial endosperm formation, a cell wall is laid down between the first two nuclei, after which one half develops endosperm along the cellular pattern and the other half along the nuclear pattern. Helobial endosperm is most commonly found in the Alismatales (monocotyledons). In many plants,…

  • HELOC (loan)

    Home equity line of credit (HELOC), a type of loan that uses a borrower’s equity in his house as collateral. In a home equity line of credit (HELOC), the lender agrees to provide up to a certain amount of money to the borrower within a specified period, the amount depending on the amount of equity

  • Heloderma (reptile)

    lizard: Dentition: The venomous lizards (Heloderma) have a longitudinal groove or fold on the inner side of each mandibular tooth; these grooves conduct the venom from the lizard to its victim.

  • Heloderma horridum (reptile)

    Gila monster: A closely related species, the Mexican beaded lizard (H. horridum), is slightly larger (to 80 cm [about 32 inches]) and darker but otherwise similar in appearance.

  • Heloderma suspectum (reptile)

    Gila monster, (Heloderma suspectum), one of two species of North American venomous lizards in the genus Heloderma of the family Helodermatidae. The Gila monster (H. suspectum) was named for the Gila River basin and occurs in the southwestern United States and northern Mexico. It grows to about 50

  • Helodermatidae (reptile family)

    lizard: Annotated classification: Varanoidea Family Helodermatidae (Gila monsters and beaded lizards) Venomous; grooved hollow fangs in lower jaw; heavy-bodied. Skin texture “beaded.” Oligocene to present; southwest United States and Mexico. Adult length to 50 cm (20 in.) in Gila monster, 80 cm (32 in.) in beaded lizard. 1 genus (Heloderma),…

  • Helodidae (insect)

    coleopteran: Annotated classification: Scirtidae, or Helodidae (marsh beetles) Small, oval; on vegetation in swampy places; aquatic larvae; about 600 species; widely distributed; example Scirtes. Superfamily Staphylinoidea Very large group; antennae with last 3 segments rarely club-shaped; outer skeleton rarely very hard, shiny; wing veins M (media) and Cu (cubitus) not connected;…

  • Helogale (genus of mammals)

    mongoose: Natural history: … (Mungos mungo), dwarf mongooses (genus Helogale), and meerkats, live in large groups. Litters usually consist of two to four young.

  • Helogale parvula (mammal)

    mongoose: …with the smallest being the dwarf mongoose (Helogale parvula), which measures 17–24 cm (7–10 inches) with a 15–20-cm (approximately 6–8-inch) tail. The largest mongoose is the white-tailed mongoose (Ichneumia albicauda), whose body length measures 48–71 cm (about 19–28 inches) long with a tail that may extend up to an additional…

  • Héloïse (French nun)

    Héloïse, wife of the theologian and philosopher Peter Abelard, with whom she was involved in one of the best known love tragedies of history. Fulbert, Héloïse’s uncle and a canon of Notre-Dame, entrusted Abelard with the education of his brilliant niece (c. 1118). The two fell in love and were

  • Helopeltis theivora (insect)

    plant bug: Helopeltis theivora is the tea blight bug of Southeast Asia. It is both common and highly destructive.

  • Helostoma temmincki (fish)

    perciform: Aquarium fishes: …and the kissing gourami (Helostoma temmincki), and various gobies (Gobiidae), blennies, and blennylike fishes of the suborder Blennioidei.

  • Helostomatidae (fish family)

    labyrinth fish: Badidae, Anabantidae, Belontiidae, Helostomatidae, and Osphronemidae.

  • helot (Greek serf)

    Helot, a state-owned serf of the ancient Spartans. The ethnic origin of helots is uncertain, but they were probably the original inhabitants of Laconia (the area around the Spartan capital) who were reduced to servility after the conquest of their land by the numerically fewer Dorians. After the

  • Helotiales (order of fungi)

    fungus: Annotated classification: Order Helotiales Pathogenic on plants, saprotrophic, endophytic, mycorhizzal, mycoparasitic, or symbiotic on roots; inoperculate asci with distinct hymenium; apothecia disk-shaped to goblet-shaped; example genera include Dactylella, Hymenoscyphus, and Ascocoryne. Order Rhytismatales

  • Helotidae (insect family)

    coleopteran: Annotated classification: Family Helotidae About 80 species in warm parts of Asia. Family Languriidae Feed on plant leaves and stems; about 400 species; e.g., Languria; mostly in Asia and North America. Family Latridiidae (minute brown scavenger beetles)

  • Hélou, Charles (president of Lebanon)

    Charles Hélou, president of Lebanon, 1964–70. Hélou was educated at St. Joseph’s University (1919–29) in Beirut and received a law degree from the French faculty of law there. He founded two French-language newspapers, L’Eclair du Nord (Aleppo, 1932) and Le Jour (Beirut, 1935–46). He served as

  • Hélou, Charles Alexandre (president of Lebanon)

    Charles Hélou, president of Lebanon, 1964–70. Hélou was educated at St. Joseph’s University (1919–29) in Beirut and received a law degree from the French faculty of law there. He founded two French-language newspapers, L’Eclair du Nord (Aleppo, 1932) and Le Jour (Beirut, 1935–46). He served as

  • Help Me Make It Through the Night (song by Kristofferson)

    Kris Kristofferson: Music career success: …1971’s best country song: “Help Me Make It Through the Night.” He recorded about a dozen of his own albums during the 1970s, three of which were collaborations with country singer Rita Coolidge, who was his wife from 1973 to 1979. Their first album, Full Moon (1973), went gold…

  • Help! (film by Lester [1965])

    Richard Lester: …by another enjoyable Beatles-Lester collaboration, Help! (1965).

  • Help! (American magazine)

    Terry Gilliam: …Harvey Kurtzman, the editor of Help!, a national humour magazine. His efforts won him a job at the publication, and his work there led to an initial meeting with English comic actor John Cleese, a future Monty Python member.

  • Help, The (film by Taylor [2011])

    Viola Davis: …rights era in the film The Help (2011) earned her Oscar and Golden Globe nods for best actress. She then appeared as a kindly stranger who tries to assist a young boy who has lost his father in the 9/11 attacks in Extremely Loud & Incredibly Close (2011), a screen…

  • helper cell (cytology)

    immune system: Helper-T-cell activation: Helper T cells do not directly kill infected cells, as cytotoxic T cells do. Instead they help activate cytotoxic T cells and macrophages to attack infected cells, or they stimulate B cells to secrete antibodies. Helper T cells become activated by interacting with antigen-presenting cells,…

  • helper lymphocyte (cytology)

    immune system: Helper-T-cell activation: Helper T cells do not directly kill infected cells, as cytotoxic T cells do. Instead they help activate cytotoxic T cells and macrophages to attack infected cells, or they stimulate B cells to secrete antibodies. Helper T cells become activated by interacting with antigen-presenting cells,…

  • helper T cell (cytology)

    immune system: Helper-T-cell activation: Helper T cells do not directly kill infected cells, as cytotoxic T cells do. Instead they help activate cytotoxic T cells and macrophages to attack infected cells, or they stimulate B cells to secrete antibodies. Helper T cells become activated by interacting with antigen-presenting cells,…

  • helper T lymphocyte (cytology)

    immune system: Helper-T-cell activation: Helper T cells do not directly kill infected cells, as cytotoxic T cells do. Instead they help activate cytotoxic T cells and macrophages to attack infected cells, or they stimulate B cells to secrete antibodies. Helper T cells become activated by interacting with antigen-presenting cells,…

  • Helper, Hinton Rowan (American author)

    Hinton Rowan Helper, the only prominent American Southern author to attack slavery before the outbreak of the American Civil War (1861–65). His thesis widely influenced Northern opinion and served as an important force in the antislavery movement. Despite his limited education, Helper was suddenly

  • Helphand, Alexander Israel Lazarevitsch (Russian socialist)

    Alexander Israel Helphand, Russian-German socialist who helped enable Lenin to reenter Russia in 1917 from exile in Switzerland, thus helping to ignite the Russian Revolution of October 1917. Helphand, the son of Jewish parents, grew up in Odessa, on the Black Sea. He was attracted to revolutionary

  • Helpman, Sir Robert Murray (Australian dancer)

    Sir Robert Helpmann, Australian ballet dancer, choreographer, actor, and director. His career encompassed activities in ballet, theatre, and motion pictures. Helpmann first appeared on the stage in 1923 as a dancer in musical comedy, and then, after seeing Anna Pavlova dance, he joined Pavlova’s

  • Helpmann, Sir Robert Murray (Australian dancer)

    Sir Robert Helpmann, Australian ballet dancer, choreographer, actor, and director. His career encompassed activities in ballet, theatre, and motion pictures. Helpmann first appeared on the stage in 1923 as a dancer in musical comedy, and then, after seeing Anna Pavlova dance, he joined Pavlova’s

  • helpmate (chess)

    chess: Heterodox problems: …such unusual stipulation is a helpmate: Black moves first and cooperates with White to get checkmated in a specified number of moves. Another is the selfmate, in which White moves first and forces Black—who is not cooperating—to deliver mate in the specified number of moves. (See the composition.) In a…

  • Helse Breughel (Flemish artist)

    Pieter Bruegel II, the Younger, Flemish painter of rustic and religious scenes and of visions of hell or Hades. The eldest son of Pieter Bruegel the Elder, the young Pieter studied first under his grandmother, the miniaturist Maria Verhulst, and then in Antwerp. He painted largely in the manner of

  • Helse Bruegel (Flemish artist)

    Pieter Bruegel II, the Younger, Flemish painter of rustic and religious scenes and of visions of hell or Hades. The eldest son of Pieter Bruegel the Elder, the young Pieter studied first under his grandmother, the miniaturist Maria Verhulst, and then in Antwerp. He painted largely in the manner of

  • Helse Brueghel (Flemish artist)

    Pieter Bruegel II, the Younger, Flemish painter of rustic and religious scenes and of visions of hell or Hades. The eldest son of Pieter Bruegel the Elder, the young Pieter studied first under his grandmother, the miniaturist Maria Verhulst, and then in Antwerp. He painted largely in the manner of

  • Helsingborg (Sweden)

    Helsingborg, city and seaport, Skåne län (county), southern Sweden. Situated at the narrowest part of The Sound (Öresund), opposite the Danish town of Helsingør (Elsinore), it is the most convenient place for motor traffic to cross to and from the European continent. Because of its situation,

  • Helsingfors (national capital, Finland)

    Helsinki, capital of Finland. It is the leading seaport and industrial city of the nation. Helsinki lies in the far south of the country, on a peninsula that is fringed by fine natural harbours and that protrudes into the Gulf of Finland. It is the most northerly of continental European capitals.

  • Helsingin Sanomat (Finnish newspaper)

    Helsingin Sanomat, (Finnish: “Helsinki News”) morning daily newspaper published in Helsinki, the largest paper in Finland and the only one of substance that remains free of political-party control. The newspaper was founded in 1889 by Eero Erkko as the Päivälehti. In 1904 it was suppressed, but it

  • Helsingør (Denmark)

    Helsingør, city, northeastern Denmark. It lies on the northeast coast of Zealand (Sjælland), at the narrowest part of The Sound (Øresund), opposite Helsingborg, Sweden, with which it is connected by ferry. A toll for crossing The Sound was introduced in medieval times, and Helsingør, which had been

  • Helsinki (national capital, Finland)

    Helsinki, capital of Finland. It is the leading seaport and industrial city of the nation. Helsinki lies in the far south of the country, on a peninsula that is fringed by fine natural harbours and that protrudes into the Gulf of Finland. It is the most northerly of continental European capitals.

  • Helsinki 1952 Olympic Games

    Helsinki 1952 Olympic Games, athletic festival held in Helsinki that took place July 19–Aug. 3, 1952. The Helsinki Games were the 12th occurrence of the modern Olympic Games. The 1952 Winter Games were the first Olympics in which the Soviet Union participated (a Russian team had last competed in

  • Helsinki Accords (international relations)

    Helsinki Accords, (August 1, 1975), major diplomatic agreement signed in Helsinki, Finland, at the conclusion of the first Conference on Security and Co-operation in Europe (CSCE; now called the Organization for Security and Co-operation in Europe). The Helsinki Accords were primarily an effort to

  • Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea Area (international agreement)

    Baltic Sea: Study and exploration: …by Baltic countries of the Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea Area, an agreement that was put into effect in 1980, revised in 1992, and reimplemented in 2000. The Helsinki Convention was one of the first international attempts to control land-based sources of…

  • Helsinki Final Act (international relations)

    Helsinki Accords, (August 1, 1975), major diplomatic agreement signed in Helsinki, Finland, at the conclusion of the first Conference on Security and Co-operation in Europe (CSCE; now called the Organization for Security and Co-operation in Europe). The Helsinki Accords were primarily an effort to

  • Helsinki Orchestral Society (Finnish orchestra)

    Robert Kajanus: In 1882 he founded the Helsinki Orchestral Society, the first complete symphony orchestra in Finland; in 1914 it united with the state’s symphony orchestra. He remained its conductor until 1932 and became known as the authoritative interpreter of the works of his friend Jean Sibelius. Kajanus also founded choral and…

  • Helsinki Philharmonic Orchestra (Finnish orchestra)

    Susanna Mälkki: …as chief conductor of the Helsinki Philharmonic Orchestra beginning in 2016–17.

  • Helsinki process (international relations)

    Helsinki process, series of events that followed the Conference for Security and Co-operation in Europe (CSCE; now called the Organization for Security and Co-operation in Europe) in 1972 and that culminated in the signing of the Helsinki Accords in 1975. Seeking to reduce tension between the

  • Helsinki Summit (international organization)

    Organization for Security and Co-operation in Europe, organization of representatives of virtually all the states of Europe, as well as the United States and Canada, committed to formalizing decisions on important questions affecting the security and stability of the European continent as a whole.

  • Helsinki Watch (international organization)

    Human Rights Watch, international nongovernmental organization that investigates and documents human rights violations and advocates for policies to prevent such abuses. Founded in 1978 as Helsinki Watch to monitor the Soviet Union’s adherence to the Helsinki Accords, the group subsequently

  • Helsinki Watch Group (Ukrainian political organization)

    Ukraine: Ukraine under Shcherbytsky: …rights provisions, in 1975, the Helsinki Watch Group was founded in Ukraine, headed by the poet Mykola Rudenko; by the end of the 1970s, its members were almost all in concentration camps or in exile abroad. The expirations of political prisoners’ sentences were increasingly followed by rearrest and new sentences…

  • Helsinki, Declaration of (1964)

    Declaration of Helsinki, formal statement of ethical principles published by the World Medical Association (WMA) to guide the protection of human participants in medical research. The Declaration of Helsinki was adopted in 1964 by the 18th WMA General Assembly, at Helsinki. Although not without its

  • Helsinki, University of (university, Helsinki, Finland)

    Finland: Education: …country achieved independence are the University of Helsinki, founded at Turku in 1640 and transferred to Helsinki in 1828, and the Helsinki University of Technology, founded in 1849. Instruction is offered in Finnish, Swedish, and often in English. State aid for higher education is available. Adult education and continuing education…

  • Helst, Bartholomeus van der (Dutch painter)

    Bartholomeus van der Helst, Dutch Baroque painter who was one of the leading portraitists of Amsterdam in the mid-17th century. Helst’s first known picture, Regents of the Walloon Orphanage (1637), is closely related to the work of Nicolaes Eliasz. Pickenoy, suggesting that the latter may have been

  • Helstein, Ralph (American labour leader)

    Ralph Helstein, American labour union official who was president of the United Packinghouse Workers of America (UPWA) from 1946 to 1968. Helstein graduated from the University of Minnesota in 1929 and received his law degree there in 1934. He immediately took a position as a labour compliance

  • Helston (England, United Kingdom)

    Helston, town (parish), Cornwall unitary authority, southwestern England. It lies on the River Cober, about 2.5 miles (4 km) from Mount’s Bay of the Atlantic Ocean. In the 13th century Helston, lying in the extreme southwest of England, was western Cornwall’s most important town, having a harbour

  • Helter Skelter (song by Lennon and McCartney)

    Paul McCartney: The Beatles: …in the USSR,” and “Helter Skelter” (all 1968), but above all he has an extraordinary gift for melodies and sometimes tags an entirely new one on to the end of a song, as he did with “Hey Jude” (1968). This facility extends to his bass playing, which is famously…

  • Helter Skelter (book by Bugliosi)

    Charles Manson: …crimes inspired the best-selling book Helter Skelter (1974).

  • Helton, Todd (American baseball player)

    Colorado Rockies: …outfielder Matt Holliday, first baseman Todd Helton, and All-Star relief pitcher Brian Fuentes went on a remarkable late-season run, winning 14 of their final 15 games, to win the franchise’s second NL Wild Card. Their hot streak extended to the playoffs, where the Rockies swept both the Philadelphia Phillies and…

  • helva (confection)

    Halvah, any of several confections of Balkan and eastern Mediterranean origin, made with honey, flour, butter, and sesame seeds or semolina, pressed into loaf form or cut into squares. Halvah is made with a variety of colourings and flavourings. Its texture is characteristically gritty and crisp.

  • helve hammer (metalwork)

    forging: …the old-fashioned smith’s technique, called helve-hammer forging, is used. The striking force is delivered by a wooden helve (handle) operating with the motion of a hand sledge. The helve hammer is usually used for preparatory and finishing operations.

  • Helvella (fungus genus)

    cup fungus: Caution is advised for all Helvella species. H. infula has a dull yellow to bay-brown, saddle-shaped cap. It grows on rotten wood and rich soil from late summer to early fall and is poisonous to some people.

  • Helvella gigas (fungus)

    cup fungus: The edible snow mushroom (Helvella gigas) is found at the edge of melting snow in some localities. Caution is advised for all Helvella species. H. infula has a dull yellow to bay-brown, saddle-shaped cap. It grows on rotten wood and rich soil from late summer to early…

  • Helvella infula

    cup fungus: …a dull yellow to bay-brown, saddle-shaped cap. It grows on rotten wood and rich soil from late summer to early fall and is poisonous to some people.

  • Helvering v. Davis (law case)

    Benjamin Nathan Cardozo: …wrote a majority opinion for Helvering v. Davis, 301 U.S. 619, and other Social Security cases (1937), upholding the federal Social Security program on the basis of the general welfare provision of the United States Constitution (Article I, section 8). In Palko v. Connecticut, 302 U.S. 319 (1937), a criminal…

  • Helvetia

    Switzerland, federated country of central Europe. Switzerland’s administrative capital is Bern, while Lausanne serves as its judicial centre. Switzerland’s small size—its total area is about half that of Scotland—and its modest population give little indication of its international significance. A

  • Helvetic Confederation

    Switzerland, federated country of central Europe. Switzerland’s administrative capital is Bern, while Lausanne serves as its judicial centre. Switzerland’s small size—its total area is about half that of Scotland—and its modest population give little indication of its international significance. A

  • Helvetic Confession (Protestant religion)

    Helvetic Confession, either of two confessions of faith officially adopted by the Reformed Church in Switzerland. The First Helvetic Confession (also called the Second Confession of Basel) was composed in 1536 by Heinrich Bullinger and other Swiss delegates, assisted by Martin Bucer of Strasbourg.

  • Helvetic Republic (Swiss history)

    Helvetic Republic, republic constituting the greater part of Switzerland, founded on March 29, 1798, after the country had been conquered by Revolutionary France. The new republic excluded both Geneva, which was annexed to France (April 1798), and the three provinces of Valtellina, Chiavenna, and

  • Helvetica, Confederaziun

    Switzerland, federated country of central Europe. Switzerland’s administrative capital is Bern, while Lausanne serves as its judicial centre. Switzerland’s small size—its total area is about half that of Scotland—and its modest population give little indication of its international significance. A

  • Helvetii (people)

    Helvetii, a Celtic people who, under pressure from Germanic peoples in the 2nd century bc, migrated from southern Germany into what is now northern Switzerland. In 61 bc, still pressed upon by the Germans, the Helvetii under Orgetorix decided to migrate to western Gaul; more than 250,000 of them

  • Helvétique, République (Swiss history)

    Helvetic Republic, republic constituting the greater part of Switzerland, founded on March 29, 1798, after the country had been conquered by Revolutionary France. The new republic excluded both Geneva, which was annexed to France (April 1798), and the three provinces of Valtellina, Chiavenna, and

  • Helvétius, Claude-Adrien (French philosopher)

    Claude-Adrien Helvétius, philosopher, controversialist, and wealthy host to the Enlightenment group of French thinkers known as Philosophes. He is remembered for his hedonistic emphasis on physical sensation, his attack on the religious foundations of ethics, and his extravagant educational theory.

  • Helvidius Priscus (Roman senator [died 93 CE])

    Domitian: …and headed by the younger Helvidius Priscus, whose father of the same name had been executed by Vespasian. Their Stoic views were probably the cause of Domitian’s expulsions of “philosophers” from Rome on two occasions. At least 12 former consuls were executed during his reign, but there is no reason…

  • Helvidius Priscus (Roman senator [died c. 70–79 CE])

    Helvidius Priscus, a Roman Stoic who forcefully upheld the principle that the emperor should act only with the consent of the Senate. Though the son of a centurion, he rose to the Senate in the reign of Nero and became praetor in 70 ce. Later his uncompromising freedom of speech brought him into

  • Helwan (Egypt)

    Ḥulwān, ancient settlement, now part of the Ḥulwān muḥāfaẓah (governorate), Egypt. It lies near the right (east) bank of the Nile River. After Egypt gained independence in 1952, it grew into an industrial suburb linked to Cairo by highway and electric railway. Ḥulwān was a centre of prehistoric and

  • Helwig, Andreas (German Protestant scholar)

    number symbolism: Arithmomancy: …beast? The German Protestant scholar Andreas Helwig in 1612 added up the Roman numerals in the phrase Vicarius Filii Dei (“Vicar of the Son of God,” a title falsely ascribed to the pope) and omitted all the other letters (that is, I = 1, V [and U, which appears as…

  • Helwingia (plant genus)

    Helwingia, genus of three species of shrubs, constituting the family Helwingiaceae in the order Aquifoliales. Native to the Himalayas and eastern Asia, all of the species in the genus have simple leaves and an unusual manner of flower growth. The plants are dioecious (male and female flowers on

  • Helwys, Thomas (English Puritan)

    Thomas Helwys, English Puritan leader, member of a Separatist group that emigrated to Amsterdam (1608), where he helped organize the first Baptist church. Returning to England (1611/12) to witness to his belief in adult Baptism and greater individual moral responsibility (against extreme Calvinist

  • Helxine soleiroli (plant)

    Urticaceae: Baby tears (Helxine soleiroli), a mosslike creeping plant with round leaves, often is grown as a ground cover. The trumpet tree (Cecropia peltata), a tropical American species that has hollow stems inhabited by biting ants, is an extremely aggressive invasive species.

  • Hélyot, Hippolyte (French historian)

    Hippolyte Hélyot, French historian and Franciscan friar whose greatest work provides the definitive and most detailed source of information on Roman Catholic religious orders and lay congregations up to the end of the 17th century. After entering the Franciscan convent of Picpus in Paris in 1683,

  • Hélyot, Pierre (French historian)

    Hippolyte Hélyot, French historian and Franciscan friar whose greatest work provides the definitive and most detailed source of information on Roman Catholic religious orders and lay congregations up to the end of the 17th century. After entering the Franciscan convent of Picpus in Paris in 1683,

  • HEMA (chemical compound)

    major industrial polymers: HEMA and cyanoacrylate polymers: …methyl methacrylate are the monomers 2-hydroxyethyl methacrylate and methyl cyanoacrylate, denoted by the chemical formulas

  • Hemachandra (Jaina author)

    Hemachandra, teacher of the Shvetambara (“White-Robed”) sect of Jainism who gained privileges for his religion from Siddharaja Jayasimha, one of the greatest kings of Gujarat. Eloquent and erudite, Hemachandra also succeeded in converting the next king, Kumarapala, thus firmly entrenching Jainism

  • Hemachatus haemachatus (snake)

    cobra: The ringhals, or spitting cobra (Hemachatus haemachatus), of southern Africa and the black-necked cobra (Naja nigricollis), a small form widely distributed in Africa, are spitters. Venom is accurately directed at the victim’s eyes at distances of more than two metres and may cause temporary, or even…

  • hemagglutinating virus of Japan (infectious agent)

    Sendai virus, (genus Respirovirus), infectious agent of the genus Respirovirus in the family Paramyxoviridae. Discovered in Sendai, Japan, the Sendai virus is naturally found in mice, rats, hamsters, guinea pigs, and pigs and primarily affects the respiratory system. The virus is highly contagious

  • hemagglutination (physiology)

    pregnancy: Symptoms and signs; biological tests: …based upon the inhibition of hemagglutination (clotting of red cells). A positive test is obtained when human chorionic gonadotropin (HCG) in the woman’s urine or blood is added to human chorionic gonadotropin antiserum (rabbit blood serum containing antibodies to HCG) in the presence of particles (or red blood cells) coated…

  • hemagglutinin (glycoprotein)

    Hemagglutinin, any of a group of naturally occurring glycoproteins that cause red blood cells (erythrocytes) to agglutinate, or clump together. These substances are found in plants, invertebrates, and certain microorganisms. Among the best-characterized hemagglutinins are those that occur as

  • hemagglutinin inhibition test (medicine)

    serological test: (3) Hemagglutinin-inhibition tests, which make use of the finding that certain viruses will cause the red blood cells of certain animal species to agglutinate (congeal, or clump together) and that this agglutination will be prevented by antibody.

  • hemangioma (pathology)

    eye disease: Tumours of the lids: …of the blood vessels, called hemangiomas, may occur in the lids and give rise to soft, bluish swellings. They are most often present at birth and tend to grow in the first few years of life, sometimes contributing to obscuration of vision and amblyopia. Often they disappear spontaneously, but they…

  • hemangioma, infantile (pathology)

    Infantile hemangioma, a congenital benign tumour made up of endothelial cells (the cells lining the inner surface of a blood vessel) that form vascular spaces, which then become filled with blood cells. Infantile hemangiomas are the most commonly occurring tumours in infants and are only rarely

  • Hemans, Felicia Dorothea (English poet)

    Felicia Dorothea Hemans, English poet who owed the immense popularity of her poems to a talent for treating Romantic themes—nature, the picturesque, childhood innocence, travels abroad, liberty, the heroic—with an easy and engaging fluency. Poems (1808), written when she was between 8 and 13, was

  • Hemantasena (Indian ruler)

    Sena dynasty: Hemantasena, the founder of the dynasty, was originally a tributary of the Pala dynasty. In the mid-11th century he declared his independence and set himself up as king. His successor, Vijayasena (reigned c. 1095–1158), built an empire on the ruins of that of the Palas,…

  • hemarthrosis (pathology)

    joint disease: Hemorrhagic joint diseases: Hemarthrosis (bleeding into the joints) is a major complication of hemorrhagic disorders. Aside from the life-threatening episodes of bleeding, it constitutes the principal disability arising from the hemophilias. Most persons with these clotting defects are affected and usually within the first years of life. Bleeding…

  • hematinic (biochemistry)

    human digestive system: Hematinics: Hematinics are substances that are essential to the proper formation of the components of blood. Examples of hematinics include folic acid, vitamin B12, and iron. In addition, vitamin D, which helps maintain the health of bones—the reservoirs of new blood cells—may also have a…

  • hematite (mineral)

    Hematite, heavy and relatively hard oxide mineral, ferric oxide (Fe2O3), that constitutes the most important iron ore because of its high iron content (70 percent) and its abundance. Its name is derived from the Greek word for “blood,” in allusion to its red colour. Many of the various forms of

  • hematite group (mineralogy)

    mineral: Oxides and hydroxides: Members of the hematite group are of the X2O3 type and have structures based on hexagonal closest packing of the oxygen atoms with octahedrally coordinated (surrounded by and bonded to six atoms) cations between them. Corundum and hematite share a common hexagonal architecture. In the ilmenite structure, iron…

  • hematocrit (medical analysis)

    Hematocrit, diagnostic procedure for the analysis of blood. The name is also used for the apparatus in which this procedure is performed and for the results of the analysis. In the procedure, an anticoagulant is added to a blood sample held in a calibrated tube. The tube is allowed to stand for one

  • hematogenous osteomyelitis (pathology)

    bone disease: Infectious diseases of bone: The incidence of hematogenous osteomyelitis reflects the fact that the body is more susceptible to invasion by microorganisms when nutrition and hygiene are poor. Thus, hematogenous osteomyelitis is common in South America, Asia, and Africa. In developed countries, hematogenous osteomyelitis is often associated with slum conditions or systemic…

  • Check out Britannica's new site for parents!
    Subscribe Today!