traffic control: Conventional control techniques: …all pilots must obey the instrument flight rule; that is, they must depend principally on the information provided by the plane’s instruments for their safety. In poor visibility and at night, instrument flight rules invariably apply. At airports, in control zones, all movements are subject to permission and instruction from…

Ifrane, town, north-central Morocco. Ifrane was founded in 1929 and is situated in the Middle Atlas (Moyen Atlas) mountains; it includes in its immediate environs Morocco’s premier winter and summer resort areas. Located at an elevation of about 5,400 feet (1,650 metres) above sea level, this

Aghlabid dynasty: …Arab Muslim dynasty that ruled Ifrīqīyah (Tunisia and eastern Algeria) from ad 800 to 909. The Aghlabids were nominally subject to the ʿAbbāsid caliphs of Baghdad but were in fact independent. Their capital city was Kairouan (al-Qayrawān), in Tunisia. The most interesting of the 11 Aghlabid emirs were the energetic…

ifrit, in Islamic mythology and folklore, a class of powerful malevolent supernatural beings. The exact meaning of the term ifrit in the earliest sources is difficult to determine. It does not occur in pre-Islamic poetry and is only used once in the Qurʾān, in the phrase “the ifrit of the jinn”

ifrit, in Islamic mythology and folklore, a class of powerful malevolent supernatural beings. The exact meaning of the term ifrit in the earliest sources is difficult to determine. It does not occur in pre-Islamic poetry and is only used once in the Qurʾān, in the phrase “the ifrit of the jinn”

ifrit, in Islamic mythology and folklore, a class of powerful malevolent supernatural beings. The exact meaning of the term ifrit in the earliest sources is difficult to determine. It does not occur in pre-Islamic poetry and is only used once in the Qurʾān, in the phrase “the ifrit of the jinn”

Gregory La Cava: Early life and work: …1917 he was heading the International Film Service (IFS), an animated cartoon studio founded by William Randolph Hearst. There La Cava collaborated with noted animator Walter Lantz. After IFS closed in 1918, La Cava continued to make animated shorts, eventually directing more than 100, some of which were based on…

Ramadan: Practices: …a festive evening meal, called ifṭār, after sundown is a central part of the holiday as well. After the sunset prayer, Muslims gather in their homes or mosques to break their fast, often joyfully shared with friends and extended family. The ifṭār usually begins with dates, as was the custom…

Ifugao, group of wet-rice agriculturalists occupying the mountainous area of northern Luzon, Philippines. They are of Malay stock and their language is Austronesian (Malayo-Polynesian), as is that of their neighbours, but they have developed a number of cultural characteristics that set them apart.

armoured vehicle: The tank is the principal fighting armoured vehicle. Other types armed with large-calibre main guns include tank destroyers and assault guns. This article traces the development of armoured personnel carriers, infantry fighting vehicles, and other armoured vehicles designed primarily as platforms for assault troops.

antibody, a protective protein produced by the immune system in response to the presence of a foreign substance, called an antigen. Antibodies recognize and latch onto antigens in order to remove them from the body. A wide range of substances are regarded by the body as antigens, including

IG Farben, (German: “Syndicate of Dyestuff-Industry Corporations”), world’s largest chemical concern, or cartel, from its founding in Germany in 1925 until its dissolution by the Allies after World War II. The IG (Interessengemeinschaft, “syndicate” or, literally, “community of interests”), partly

magnesium processing: History: …chloride (now known as the IG Farben process) as well as the technology for electrolyzing this product to magnesium metal and chlorine. Other contributions by IG Farben were the development of numerous cast and malleable alloys, refining and protective fluxes, wrought magnesium products, and a vast number of aircraft and…

antibody: Antibody structure and classes: IgA, IgD, and IgE. The classes of antibody differ not only in their constant region but also in activity. For example, IgG, the most common antibody, is present mostly in the blood and tissue fluids, while IgA is found in the mucous membranes lining the…

blood transfusion: Transfusion-induced immune reactions: These patients, described as IgA-deficient because they do not make IgA, can have a severe allergic reaction characterized by anaphylaxis with vascular collapse, severe drop in blood pressure, and respiratory distress. This problem can be treated by using washed red cells to remove the remaining plasma containing IgA or…

keffiyeh: Variations: …thick black cord called the ʿiqāl is tied around the ghutrah to secure it to the head. This variation is worn primarily in the Gulf States, including Bahrain, Qatar, and the United Arab Emirates. In Iran the chafiyeh is worn atop the head and is typically checkered in a dark…

Igala, a largely Muslim people of Nigeria, living on the left bank of the Niger River below its junction with the Benue River. Their language belongs to the Benue-Congo branch of the Niger-Congo family. Their ruler, the ata, traditionally also governed two other groups, the Bassa Nge and the Bass

Benue-Congo languages: Defoid: members are Yoruba (20,000,000 speakers), Igala (1,000,000), and Itsekiri (Itsεkiri; 600,000). Yoruba is the Niger-Congo language with the largest number of mother-tongue speakers. Though Swahili has a greater total number of speakers—some 35,000,000—most of them are second-language speakers. One of the principal languages of Nigeria, Yoruba is spoken throughout southwestern…

Amazon basin: Amazon basin ecosystems: …that add to their fertility—and igapó—i.e., forests flooded annually by black water (in which tannins and humic acid cause the water to appear darker and increase its acidity) that contain slow-growing trees and a few other plants (see also Amazon River).

Igala, a largely Muslim people of Nigeria, living on the left bank of the Niger River below its junction with the Benue River. Their language belongs to the Benue-Congo branch of the Niger-Congo family. Their ruler, the ata, traditionally also governed two other groups, the Bassa Nge and the Bass

Kawaíb: …remaining Parintintin live on the Igarapé Ipixuna, a tributary of Lake Uruapiára, or have become rubber workers on the Madeira River.

Igarashi Family was a group of Japanese lacquerware artists who specialized in the maki-e technique, wherein a design is made by sprinkling minute gold, silver, or copper flakes over a lacquer ground. The founder of the Igarashi family, Shinsai, contributed to the art by perfecting two techniques

graphic design: Postmodern graphic design: …the work of Japanese designer Igarashi Takenobu. After studying design fundamentals in Los Angeles, Igarashi began his independent design practice in Tokyo and used basic design elements—point, line, plane, grids, and isometric perspectives—as the building blocks of his work. This design vocabulary enabled him to invent imaginative solutions. His poster…

Igarka, city, Krasnoyarsk kray (territory), northwestern Siberia, Russia. It is 60 miles (100 km) north of the Arctic Circle. The city lies along the Yenisey River, 418 miles (673 km) from the sea, but is accessible to oceangoing vessels. It was founded in 1929. The city is an important wood-export

African art: Edo peoples: …cult of the water spirit Igbile. Both the cult and the sculptural style seem to have derived from the Ijo.

Igbira, inhabitants of the areas northeast and southwest of the confluence of the Niger and Benue rivers in central Nigeria. Their language is usually classified as a Nupoid variety within the Benue-Congo branch of the Niger-Congo language family. The two main habitats within the Igbira area are a

Igbira, inhabitants of the areas northeast and southwest of the confluence of the Niger and Benue rivers in central Nigeria. Their language is usually classified as a Nupoid variety within the Benue-Congo branch of the Niger-Congo language family. The two main habitats within the Igbira area are a

Igbo, people living chiefly in southeastern Nigeria who speak Igbo, a language of the Benue-Congo branch of the Niger-Congo language family. The Igbo may be grouped into the following main cultural divisions: northern, southern, western, eastern or Cross River, and northeastern. Before European

In 1803, having just overpowered their captors on a small slave vessel off the coast of a small island in Georgia, a group of Igbo people chose death over a life of enslavement and defiantly waded into the cool coastal waters and drowned. One of the largest mass suicides of enslaved West Africans

D.O. Fagunwa: His second novel, Igbo Olodumare (“The Forest of God”), was published in 1949. He also wrote Ireke Onibudo (1949; “The Sugarcane of the Guardian”), Irinkerindo Ninu Igbo Elegbeje (1954; “Wanderings in the Forest of Elegbeje”), and Adiitu Olodumare (1961; “The Secret of the Almighty”); a number of short…

western Africa: The wider influence of the Sudanic kingdoms: …government, the archaeological finds at Igbo Ukwu revealed that ancestors of the modern Igbo (Ibo) had, as early as the 9th century, a sophisticated society with surpluses of wealth supporting considerable craft specialization, including a highly developed bronze art with a distinctive style of its own. Recent thinking suggests that…

Igboid languages, a language cluster that constitutes a subbranch of the Benue-Congo branch of the Niger-Congo language family. There are nearly 20 million speakers of Igboid languages in southeastern Nigeria. In the early years of the 20th century an attempt to develop an artificial form of Igbo

Kieran Culkin: Screen and stage roles: …a rebellious high-school dropout, in Igby Goes Down. Culkin’s performance earned him much attention and praise, as well as a Golden Globe nomination for best actor in a musical or comedy. He then stepped away from the spotlight and took on a series of supporting roles, such as in the…

flag of Iraq: On April 26, 2004, the Iraqi Governing Council announced a new national flag, its design consisting of four unequal horizontal stripes from top to bottom of white, blue, yellow, and blue and with a light blue crescent centred on the white stripe. The flag, almost universally rejected by Iraqis, was…

Quaternary: …was made at the 18th International Geological Congress (IGC) in London that the base of the Pleistocene Series should be fixed in marine rocks exposed in the coastal areas of Calabria in southern Italy. As ratified by the International Commission on Stratigraphy (ICS) in 1985, the type section for boundary…

Intergovernmental Committee on Refugees (IGCR or ICR), agency created in 1938 on the initiative of U.S. Pres. Franklin D. Roosevelt to administer intergovernmental efforts to resettle refugees from Nazi Germany and to prepare for the resettlement of future German emigrants, thus originating planned

antibody: Antibody structure and classes: IgD, and IgE. The classes of antibody differ not only in their constant region but also in activity. For example, IgG, the most common antibody, is present mostly in the blood and tissue fluids, while IgA is found in the mucous membranes lining the respiratory…

igloo, temporary winter home or hunting-ground dwelling of Canadian and Greenland Inuit (Eskimos). The term igloo, or iglu, from Eskimo igdlu (“house”), is related to Iglulik, a town, and Iglulirmiut, an Inuit people, both on an island of the same name. The igloo, usually made from blocks of snow

antibody: Antibody structure and classes: IgA, IgD, and IgE. The classes of antibody differ not only in their constant region but also in activity. For example, IgG, the most common antibody, is present mostly in the blood and tissue fluids, while IgA is found in the mucous membranes lining the respiratory and gastrointestinal…

Generation Z, term used to describe Americans born during the late 1990s and early 2000s. Some sources give the specific year range of 1997–2012, although the years spanned are sometimes contested or debated because generations and their zeitgeists are difficult to delineate. Generation Z follows

Bernhard Severin Ingemann: …“Igennem nat og trængsel” (“Through the Night of Doubt and Sorrow”), well known in English translation. To a lesser extent, he is also remembered for his historical novels.

Disney Company: Continuing expansion: ABC, Pixar, Marvel Entertainment, and Lucasfilm: …succeeded by former ABC chairman Robert Iger. Iger oversaw a dramatic expansion of the Disney brand and orchestrated a string of high-profile acquisitions. In 2006 Disney purchased Pixar for $7.4 billion, and it acquired Marvel Entertainment, a company best known as a comic book publisher, for $4 billion in 2009.

Will Eisner: Career in comics and graphic novels: His first sale was to Jerry Iger, the editor of Wow, What a Magazine!, for which he created the character Captain Scott Dalton, a globe-trotting adventurer. Eisner’s other work for Wow included the detective series Harry Karry and the pirate comic The Flame.

Disney Company: Continuing expansion: ABC, Pixar, Marvel Entertainment, and Lucasfilm: …succeeded by former ABC chairman Robert Iger. Iger oversaw a dramatic expansion of the Disney brand and orchestrated a string of high-profile acquisitions. In 2006 Disney purchased Pixar for $7.4 billion, and it acquired Marvel Entertainment, a company best known as a comic book publisher, for $4 billion in 2009.

insulin-like growth factor (IGF), any of several peptide hormones that function primarily to stimulate growth but that also possess some ability to decrease blood glucose levels. IGFs were discovered when investigators began studying the effects of biological substances on cells and tissues outside

insulin-like growth factor: There are two IGFs: IGF-1 and IGF-2. These two factors, despite the similarity of their names, are distinguishable in terms of specific actions on tissues because they bind to and activate different receptors. The major action of IGFs is on cell growth. Indeed, most of the actions of pituitary…

cancer: Milestones in cancer science: …gene known as IGF2 (insulin-like growth factor 2), for instance, has been linked to an increased risk for certain types of cancer, including colorectal cancer and nephroblastoma. Other products of regulatory genes, such as microRNAs, have also been implicated in the malignant transformation of cells, and it is likely…

fishing: Big-game fishing: The establishment of the International Game Fish Association (IGFA) in 1939 did much to promote big-game fishing and to regulate it—supervising marine fishing competitions, establishing various weight categories for lines, and keeping championship records. The IGFA also promoted scientific study by encouraging the tagging of released fish to establish…

antibody: Antibody structure and classes: …abbreviation of the word immunoglobulin: IgG, IgM, IgA, IgD, and IgE. The classes of antibody differ not only in their constant region but also in activity. For example, IgG, the most common antibody, is present mostly in the blood and tissue fluids, while IgA is found in the mucous membranes…

Aḥad Haʿam: …spent in Palestine, editing his Iggerot Aḥad Haʿam, 6 vol. (1923–25; “Letters of Aḥad Haʿam”). Further letters, principally from the last phase of his life, and his memoirs were published in Aḥad Haʿam: Pirqe zikhronot we-iggerot (1931; “Collected Memoirs and Letters”). His essays comprise four volumes (1895, 1903, 1904, and…

Judy Blume: Early life and first publications: …she published a version of Iggie’s House in Trailblazer magazine; she rewrote it for publication in book form in 1970.

Iggy and the Stooges, American rock band, initially active in the late 1960s and early 1970s, that helped define punk music. Both with the Stooges and in his subsequent solo career, Iggy Pop had a far-reaching influence on later performers. The principal members of the band were vocalist Iggy Pop

Relizane, town, northwestern Algeria, near Wadi Mîna, which is a tributary of the Chelif River. Built near the ruined Roman settlement of Mina, modern Relizane is a typical French-style town of wide streets and parks. It is surrounded by orchards and gardens, and a large area of cropland is

manor house: …battlements, gatehouse, and moat—as at Ightham Mote, Kent. Ockwells Manor in Berkshire is a typical timber-framed manor house built in the 15th century without defensive elements.

Jijel, town and roadstead port, northeastern Algeria, on the Mediterranean seacoast and the western edge of the Collo Kabylie region. The city of Jijel, originally a Phoenician trading post, passed successively to the Romans (as Igilgili), the Arabs, and, in the 16th century, to the pirate Khayr

Giglio Island, mountainous, volcanic islet of the Tuscan Archipelago, in the Tyrrhenian Sea, opposite Mount Argentario, on the west coast of Italy. The island rises to 1,634 feet (498 metres) and has an area of 8 square miles (21 square km). Wine is produced, and there is considerable offshore

Calgary Flames: …Theo Fleury (until 1999) and Jarome Iginla. In 2003–04 the team returned to the playoffs and proceeded to defeat three higher-seeded teams to make an unlikely appearance in the Stanley Cup finals. There the Flames played a thrilling series with the Tampa Bay Lightning in which the final four contests…

Jihlava, city, south-central Czech Republic. It lies in the Bohemian-Moravian Highlands, along the Jihlava River. From about 1240, its prosperity rested on its silver mines. A royal mint operated there from about 1260, and a codified town mining law (Ius Regale Montanorum) served as a model for

Germany: The Hussite wars: …with the council by the Compact of Iglau (July 5, 1436), which conceded them communion in both kinds and reunited them with the Roman Catholic church. The Utraquist nobles extracted far better terms from Sigismund as the price of their recognition. He agreed to accept the guidance of Czech councillors…

Andes Mountains: Physiography of the Central Andes: … (more than 10,000 feet), and Iglesia (13,400 feet). Farther north the passes are more numerous but higher. The peaks of Mounts Bonete, Ojos del Salado, and Pissis surpass 20,000 feet.

Philippine Independent Church, independent church organized in 1902 after the Philippine revolution of 1896–98 as a protest against the Spanish clergy’s control of the Roman Catholic Church. Cofounders of the church were Isabelo de los Reyes y Florentino, author, labour leader, and senator, who was

Iglesia ni Cristo (INC), international Christian religious movement that constitutes the largest indigenous Christian church in the Philippines. It was established by Félix Ysagun Manalo in 1914. Manalo (birth name Félix Manalo ý Ysagun) was raised in the Roman Catholic Church but left as a

Iglesia ni Cristo (INC), international Christian religious movement that constitutes the largest indigenous Christian church in the Philippines. It was established by Félix Ysagun Manalo in 1914. Manalo (birth name Félix Manalo ý Ysagun) was raised in the Roman Catholic Church but left as a

Iglesias, town and episcopal see, southwestern Sardinia, Italy. It lies west-northwest of Cagliari city. The town’s cathedral dates from 1288, and the 15th-century Church of San Francesco is a good example of Franciscan architecture in Sardinia. Iglesias is the centre of a region in which lead,

Julio Iglesias is a Spanish singer and songwriter whose romantic image, magnetic stage presence, and expressive music made him one of the best-selling artists of all time. By the early 21st century, he had sold hundreds of millions of albums in more than a dozen languages. Iglesias was born and

Spain: Economic recovery and Catalonian independence: …led by the youthful, charismatic Pablo Iglesias Turrión, Podemos ran on an anti-austerity platform while presenting itself as a movement of neither the left nor the right but one that was opposed to the corrupt and self-serving political and economic elites.

Julio Iglesias is a Spanish singer and songwriter whose romantic image, magnetic stage presence, and expressive music made him one of the best-selling artists of all time. By the early 21st century, he had sold hundreds of millions of albums in more than a dozen languages. Iglesias was born and

Pablo Iglesias was a political leader who played a significant role in the development of Spanish democratic socialism and trade unionism. Iglesias was raised in a foundling home and eventually became a printer. He helped found the Spanish Socialist Workers’ Party (Partido Socialista Obrero

Puerto Rico: Political developments: …the highly respected labour leader Santiago Iglesias, remained focused on the plight of Puerto Rico’s labouring classes, but its program had little support, because popular attention was largely concentrated on the political status of the island.

igloo, temporary winter home or hunting-ground dwelling of Canadian and Greenland Inuit (Eskimos). The term igloo, or iglu, from Eskimo igdlu (“house”), is related to Iglulik, a town, and Iglulirmiut, an Inuit people, both on an island of the same name. The igloo, usually made from blocks of snow

igloo, temporary winter home or hunting-ground dwelling of Canadian and Greenland Inuit (Eskimos). The term igloo, or iglu, from Eskimo igdlu (“house”), is related to Iglulik, a town, and Iglulirmiut, an Inuit people, both on an island of the same name. The igloo, usually made from blocks of snow

igloo, temporary winter home or hunting-ground dwelling of Canadian and Greenland Inuit (Eskimos). The term igloo, or iglu, from Eskimo igdlu (“house”), is related to Iglulik, a town, and Iglulirmiut, an Inuit people, both on an island of the same name. The igloo, usually made from blocks of snow

antibody: Antibody structure and classes: …of the word immunoglobulin: IgG, IgM, IgA, IgD, and IgE. The classes of antibody differ not only in their constant region but also in activity. For example, IgG, the most common antibody, is present mostly in the blood and tissue fluids, while IgA is found in the mucous membranes lining…

Institut Géographique National (IGN), one of the foremost centres of mapmaking and geographic research in France, specializing in aerial and ground surveys and maps; it is located in Paris. Its origins can be traced to a mapmaking group organized in 1719, the Engineers and Geographers for Armies

St. Ignatius of Loyola ; canonized March 12, 1622; feast day July 31) was a Spanish theologian and mystic who became one of the most influential figures in the Roman Catholic Counter-Reformation in the 16th century. In 1534 he formed a religious brotherhood in Paris known as the Society of Jesus

primate: Paleocene: …available for the genera Plesiadapis, Ignacius, and Palaechthon from Europe and North America. The skulls show a number of dental specializations, including, in the case of Plesiadapis, procumbent rodentlike incisors in the upper and lower jaw and the absence of other antemolar teeth, though the molar teeth show more plausible…

Louis Ignarro is an American pharmacologist who, along with Robert F. Furchgott and Ferid Murad, was co-awarded the 1998 Nobel Prize in Physiology or Medicine for the discovery that nitric oxide (NO) acts as a signaling molecule in the cardiovascular system. This work uncovered an entirely new

Louis Ignarro is an American pharmacologist who, along with Robert F. Furchgott and Ferid Murad, was co-awarded the 1998 Nobel Prize in Physiology or Medicine for the discovery that nitric oxide (NO) acts as a signaling molecule in the cardiovascular system. This work uncovered an entirely new

Louis Ignarro is an American pharmacologist who, along with Robert F. Furchgott and Ferid Murad, was co-awarded the 1998 Nobel Prize in Physiology or Medicine for the discovery that nitric oxide (NO) acts as a signaling molecule in the cardiovascular system. This work uncovered an entirely new

education: Before 1917: …the minister of education, Count P.N. Ignatev, started serious reforms to modernize the secondary schools and to establish a system of vocational and technical education, which he regarded as most important for the industrialization of Russia. During the Provisional Government (February to October 1917, Old Style), the universities were granted…

Michael Ignatieff is a Canadian author, literary critic, and politician who represented the Etobicoke-Lakeshore riding in the Canadian House of Commons (2006–11) and who served as leader of the Liberal Party (2008–11). Ignatieff’s paternal grandparents were Russian nobles who fled to Canada in the

Michael Ignatieff is a Canadian author, literary critic, and politician who represented the Etobicoke-Lakeshore riding in the Canadian House of Commons (2006–11) and who served as leader of the Liberal Party (2008–11). Ignatieff’s paternal grandparents were Russian nobles who fled to Canada in the

Nikolay Pavlovich, Count Ignatyev was a pan-Slavist diplomat and statesman who played a major role in the administration of Russia’s foreign policy in Asia under Tsar Alexander II (reigned 1855–81). Having become an officer in the Russian Guards at 17, Ignatyev began his diplomatic career in 1856

St. Ignatius of Antioch ; Western feast day October 17; Eastern feast day December 20) was the third bishop of Antioch, Syria (now in Turkey), known mainly from seven highly regarded letters that he wrote during a trip to Rome as a prisoner condemned to be executed for his Christian beliefs. He was

Byzantine Empire: The Iconoclastic controversy: In the patriarch Ignatius (847–858; 867–877) they discovered a spokesman after their own hearts: one drawn from the monastic ranks and contemptuous of all the allurements that the world of secular learning seemed to offer. More significant than the men to be found on the other extreme, iconoclast…

St. Ignatius of Loyola ; canonized March 12, 1622; feast day July 31) was a Spanish theologian and mystic who became one of the most influential figures in the Roman Catholic Counter-Reformation in the 16th century. In 1534 he formed a religious brotherhood in Paris known as the Society of Jesus

St. Ignatius of Antioch ; Western feast day October 17; Eastern feast day December 20) was the third bishop of Antioch, Syria (now in Turkey), known mainly from seven highly regarded letters that he wrote during a trip to Rome as a prisoner condemned to be executed for his Christian beliefs. He was

David Ignatow was an American poet whose works address social as well as personal issues in meditative, vernacular free verse. Ignatow worked for a time as a journalist with the WPA Federal Writers’ Project. His first book of poetry, entitled Poems (1948), was followed by The Gentle Weight Lifter

Nikolay Pavlovich, Count Ignatyev was a pan-Slavist diplomat and statesman who played a major role in the administration of Russia’s foreign policy in Asia under Tsar Alexander II (reigned 1855–81). Having become an officer in the Russian Guards at 17, Ignatyev began his diplomatic career in 1856

George Herriman: …the same: Krazy Kat loved Ignatz Mouse, but the malicious Ignatz would have none of it and took every opportunity to throw a brick at Krazy. The policeman Offissa Pupp tried to protect Krazy, often by putting Ignatz in jail. The three principals were perpetually oblivious to each other’s actual…

agglomerate: Upon accumulation, blocks form breccia, which are solid angular fragments larger than 64 mm.

geology: Igneous petrology: Igneous petrology is concerned with the identification, classification, origin, evolution, and processes of formation and crystallization of the igneous rocks. Most of the rocks available for study come from the Earth’s crust, but a few, such as eclogites, derive from the mantle. The…

igneous rock, any of various crystalline or glassy rocks formed by the cooling and solidification of molten earth material. Igneous rocks constitute one of the three principal classes of rocks, the others being metamorphic and sedimentary. Igneous rocks are formed from the solidification of magma,

António Ferreira: His tragedy Castro (written c. 1558) was one of the first in modern European literature. It takes as its subject the death of the Portuguese national heroine Inês de Castro, who was murdered by Afonso IV—the father of Dom Pedro, her lover—for reasons of state, a theme…

archaea: Habitats of the archaea: …the surface of another archaea, Ignicoccus. Nanoarchaea, which were discovered in 2002, contain both the smallest known living cell (1/100th the size of Escherichia coli) and the smallest known genome (112 kilobases [1 kilobase = 1,000 base pairs of DNA]; for comparison, the human genome contains 3.2 billion base pairs).…

ignimbrite, rock composed of compacted volcanic ejecta (see

jack-o’-lantern, in meteorology, a mysterious light seen at night flickering over marshes; when approached, it advances, always out of reach. The phenomenon is also known as will-o’-the-wisp and ignis fatuus (Latin: “foolish fire”). In popular legend it is considered ominous and is often purported

hazardous-waste management: Hazardous-waste characteristics: Ignitable wastes burn at relatively low temperatures and may cause an immediate fire hazard. Corrosive wastes include strong acidic or alkaline substances. They destroy solid material and living tissue upon contact, by chemical reaction.

explosive: Ignition of black powder: Black powder is relatively insensitive to shock and friction and must be ignited by flame or heat. In the early days such devices as torches, glowing tinder, and heated iron rods were used to ignite the powder and, in most cases,…

nuclear fusion: Conditions for practical fusion yield: …this balance is called the ignition condition. An equation relates the product of density and energy confinement time, denoted nτ, to a function that depends only on the plasma temperature and the type of fusion reaction. For example, when the plasma is composed of deuterium and tritium, the smallest value…