- achondrite (meteorite)
achondrite, any stony meteorite containing no chondrules (small, roughly spherical objects that formed in the solar nebula). The only exclusions are carbonaceous chondrites of the CI group, which, though they are clearly chondrites, are so heavily altered by water that any evidence for their having
- achondroplasia (genetics)
achondroplasia, genetic disorder characterized by an abnormality in the conversion of cartilage into bone. As a consequence, bones that depend on cartilage models for development, particularly long bones such as the femur and humerus, cannot grow. Achondroplasia is the most common cause of
- Achoris (king of Egypt)
ancient Egypt: The 28th, 29th, and 30th dynasties: Achoris (ruled 393–380 bce), its third ruler, was especially vigorous, and the prosperity of his reign is indicated by many monuments in Upper and Lower Egypt. Once again Egypt was active in international politics, forming alliances with the opponents of Persia and building up its…
- Achras (plant genus)
Rainforest Regeneration in Panama: …are tree species such as Manilkara, almendro, and the suicide tree, characterized by slower growth and lower light requirements, with the capacity for extended persistence under low light conditions. Such trees tend toward high wood densities, relatively delayed attainment of reproductive status, and larger, often animal-dispersed seeds. They also have…
- Achras zapota (tree and fruit)
sapodilla, (Manilkara zapota), tropical evergreen tree (family Sapotaceae) and its distinctive fruit, native to southern Mexico, Central America, and parts of the Caribbean. Though of no great commercial importance in any part of the world, the sapodilla is much appreciated in many tropical and
- Achroia grisella (insect)
beekeeping: Pests: The larvae of the lesser wax moth, Achroia grisella, cause damage to stored combs similar to that of the greater wax moth. The Mediterranean flour moth larva, Anagasta kuehniella, feeds on pollen in the combs and causes some damage. Control for both of these moths is the same as…
- achroite (mineral)
tourmaline: …(Brazilian emerald), or colourless (achroite). Some crystals are pink at one end and green at the other; concentric colour zoning may also occur. The coloured varieties, when transparent and free from flaws, are cut as gems.
- achromatic lens (optics)
biology: The discovery of cells: …solved until the invention of achromatic lenses, which were introduced about 1830. In 1878 a modern achromatic compound microscope was produced from the design of the German physicist Ernst Abbe. Abbe subsequently designed a substage illumination system, which, together with the introduction of a new substage condenser, paved the way…
- achromatic point (optics)
colour: Tristimulus measurement and chromaticity diagrams: The achromatic point is the central point at x = 13, y = 13 (shown as W in the figure), where visually perceived white is located (as well as the pure grays and black, which vary only in the magnitude of the luminance Y).
- Achromatium (bacteria)
bacteria: Diversity of structure of bacteria: …5 μm or more; and Achromatium, which has a minimum width of 5 μm and a maximum length of 100 μm, depending on the species. Giant bacteria can be visible with the unaided eye, such as Thiomargarita namibiensis, which averages 750 μm in diameter; T. magnifica, which averages 700 μm…
- achromatopsia (ophthalmology)
colour blindness: Types of colour blindness: …conditions are rare and include achromatopsia (or rod monochromacy; the complete absence of functional cone photopigments) and cone monochromacy (when two of the three cone types are nonfunctional).
- Achterberg, Gerrit (Dutch poet)
Gerrit Achterberg was a Dutch poet whose use of surreal language and imagery influenced a generation of post-World War II poets known as the Experimentalists. His verse, traditional in form, is characterized as romantic and metaphysical. He was a linguistic innovator, often coining new words based
- Achterhoek (region, Netherlands)
Gelderland: …on the west and the Achterhoek on the east. The hill plateau of the Veluwe is covered with scantily cultivated heaths and some woods, of primarily fir and beech. There are two national parks (Hoge Veluwe and Veluwezoom) and a wildlife reserve. Much of the Veluwe is used for military…
- Achterhuis, Het (work by Frank)
The Diary of a Young Girl, journal by Anne Frank, a Jewish teenager who chronicled her family’s two years (1942–44) in hiding during the German occupation of the Netherlands during World War II. The book was first published in 1947—two years after Anne’s death in a concentration camp—and later
- Achtung Baby (album by U2)
U2: …in 1991 with the album Achtung Baby and a sound heavily influenced by European experimental, electronic, and disco music. With this came a stage show that trafficked in irony and self-deprecating humour, qualities virtually absent from the band’s music in the previous decade; the 1992 Zoo TV tour was one…
- Achtung! Panzer! (work by Guderian)
Heinz Guderian: His Achtung! Panzer! (1937; Attention! Tanks!) incorporated many of the theories of the British general J.F.C. Fuller and General Charles de Gaulle, who advocated the creation of independent armoured formations with strong air and motorized infantry support, intended to increase mobility on the battlefield by quick penetrations of enemy…
- Achtzehnte Brumaire des Louis Bonaparte, Der (essay by Marx)
Karl Marx: Early years in London of Karl Marx: …Brumaire des Louis Napoleon” (The Eighteenth Brumaire of Louis Bonaparte), with its acute analysis of the formation of a bureaucratic absolutist state with the support of the peasant class. In other respects the next 12 years were, in Marx’s words, years of “isolation” both for him and for Engels…
- Achy Breaky Heart (song by Von Tress)
Billy Ray Cyrus: …for his 1992 song “Achy Breaky Heart,” a smash hit that crossed over to the pop charts and inspired a line dancing craze. He also acted in several television series, including Hannah Montana (2006–11), a family-friendly show that launched the career of his daughter, the actress and singer Miley…
- Achyuta Deva Rāya (Vijayanagar ruler)
India: Renewed decentralization: …and picked his half brother Achyuta Deva Raya (reigned 1529–42) to succeed him. Following a brief succession dispute, Achyuta Deva Raya was able to reach the capital from Chandragiri, where Krishna Deva had kept him and other princes confined, and to ascend the throne. Although he probably was not as…
- acicular texture (mineralogy)
mineral: Crystal habit and crystal aggregation: …slender fibres, parallel or radiating; acicular, slender, needlelike crystals; radiating, individuals forming starlike or circular groups; globular, radiating individuals forming small spherical or hemispherical groups; dendritic, in slender divergent branches, somewhat plantlike; mammillary, large smoothly rounded, masses resembling mammae, formed by radiating crystals; botryoidal,
- acid (chemical compound)
acid, any substance that in water solution tastes sour, changes the colour of certain indicators (e.g., reddens blue litmus paper), reacts with some metals (e.g., iron) to liberate hydrogen, reacts with bases to form salts, and promotes certain chemical reactions (acid catalysis). Examples of acids
- acid anhydride (chemical compound)
chemical compound: Carboxylic acids: …chlorine or bromine atom; and anhydrides have an attached carboxyl group. Each type of acid derivative has a set of characteristic reactions that qualifies it as a unique functional group, but all acid derivatives can be readily converted to a carboxylic acid under appropriate reaction conditions. Many simple esters are…
- Acid Band (Zimbabwean musical group)
Thomas Mapfumo: In 1976 Mapfumo formed the Acid Band, which produced a blend of popular and traditional music as a vehicle to carry thinly veiled political messages; that music was called chimurenga (Shona: “struggle”). The band’s first album, released in 1977, was titled Hokoyo! (“Watch Out!”).
- acid bite (art)
printmaking: Acids and the etching process: The acid bite of the plate is a critical stage in the making of an etching. The printmaker must be familiar with the characteristics of the materials that are being used. On a zinc plate nitric acid is used. In the process of biting, this acid…
- Acid Black 1 (dye)
dye: Azo dyes: Acid Black 1 is formed by coupling first to diazotized p-nitroaniline in weakly acidic solution and then to diazotized aniline in alkaline solution.
- acid chloride (chemical compound)
carboxylic acid: Acyl halides: The functional group of an acyl halide (acid halide) is an acyl group (RCO―) bonded to a halogen atom. They are named by changing the suffix -ic acid in the name of the parent carboxylic acid to -yl halide. Because…
- acid deposition (pollution)
acid rain, precipitation possessing a pH of about 5.2 or below primarily produced from the emission of sulfur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and NO2) from human activities, mostly the combustion of fossil fuels. In acid-sensitive landscapes, acid deposition can reduce
- acid dye (chemical compound)
acid dye, any bright-coloured synthetic organic compound whose molecule contains two groups of atoms—one acidic, such as a carboxylic group, and one colour-producing, such as an azo or nitro group. Acid dyes are usually applied in the form of their sodium salts, chiefly on wool but also on silk
- acid halide (chemical compound)
acid halide, neutral compound that reacts with water to produce an acid and a hydrogen halide. Acid halides are ordinarily derived from acids or their salts by replacement of hydroxyl groups by halogen atoms. The most important organic acid halides are the chlorides derived from carboxylic acids
- acid house (music)
Daft Punk: …of house music known as acid house. Their debut album, Homework (1997), won them further acclaim within the dance music scene, and the buoyant single “Around the World”—which featured a looped, electronically processed vocal—helped introduce the act to a wider audience.
- acid hydrolase (enzyme)
lysosome: …variety of hydrolytic enzymes (acid hydrolases) that break down macromolecules such as nucleic acids, proteins, and polysaccharides. These enzymes are active only in the lysosome’s acidic interior; their acid-dependent activity protects the cell from self-degradation in case of lysosomal leakage or rupture, since the pH of the cell is…
- acid indigestion
nutritional disease: Heartburn and peptic ulcer: When gastric contents, containing hydrochloric acid, flow backward from the stomach, the lining of the esophagus becomes inflamed, leading to the burning sensation known as heartburn. Occasional heartburn (also known as acid indigestion) is a common occurrence, typically
- acid leaching (industrial process)
uranium processing: Leaching: Acid leaching is commonly performed by agitating an ore-leach mixture for 4 to as long as 48 hours at ambient temperature. Except in special circumstances, sulfuric acid is the leachant used; it is supplied in amounts sufficient to obtain a final leach liquor at about…
- acid lead (alloy)
lead processing: The metal and its alloys: Acid lead, made by adding copper to fully refined lead, differs from chemical lead primarily in its higher bismuth content.
- acid maltase deficiency (pathology)
Pompe’s disease, hereditary defect in the body’s ability to metabolize glycogen, resulting in a muscle disorder that is usually fatal during the first year of life. The defect responsible, absence of the enzyme alpha-1,4-glucosidase, is extremely rare, occurring in fewer than one in every 150,000
- acid phosphatase (enzyme)
enzyme analysis: …hepatitis and obstructive jaundice; (4) acid phosphatase, an enzyme found in most body tissue but in unusually high concentration in the adult prostate gland; it is released into the circulation in metastatic cancer of the prostate; (5) peptidases, a group of enzyme-digesting proteins found in greater concentrations in the serum…
- acid precipitation (pollution)
acid rain, precipitation possessing a pH of about 5.2 or below primarily produced from the emission of sulfur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and NO2) from human activities, mostly the combustion of fossil fuels. In acid-sensitive landscapes, acid deposition can reduce
- acid rain (pollution)
acid rain, precipitation possessing a pH of about 5.2 or below primarily produced from the emission of sulfur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and NO2) from human activities, mostly the combustion of fossil fuels. In acid-sensitive landscapes, acid deposition can reduce
- Acid Rain Program (United States government program)
emissions trading: Acid rain and greenhouse gases: …large-scale practical application in the Acid Rain Program run by the U.S. Environmental Protection Agency in the 1990s. In 1990, amendments to the U.S. Clean Air Act of 1970 called for a halving of emissions of sulfur dioxide (SO2) within two decades, along with a parallel ambitious reduction in emissions…
- acid rock (igneous rock)
felsic and mafic rocks, division of igneous rocks on the basis of their silica content. Chemical analyses of the most abundant components in rocks usually are presented as oxides of the elements; igneous rocks typically consist of approximately 12 major oxides totaling over 99 percent of the rock.
- acid-base catalysis (chemistry)
acid-base catalysis, acceleration of a chemical reaction by the addition of an acid or a base, the acid or base itself not being consumed in the reaction. The catalytic reaction may be acid-specific (acid catalysis), as in the case of decomposition of the sugar sucrose into glucose and fructose in
- acid-base equilibrium (chemical reaction)
acid–base reaction: Acid–base equilibria: Certain general principles apply to any solvent with both acidic and basic properties—for example, water, alcohols, ammonia, amines, and acetic acid. Denoting the solvent molecule by SH, proton transfer can give rise to the ions SH2+ and S−, sometimes called lyonium and lyate…
- acid–base reaction (chemistry)
acid–base reaction, a type of chemical process typified by the exchange of one or more hydrogen ions, H+, between species that may be neutral (molecules, such as water, H2O; or acetic acid, CH3CO2H) or electrically charged (ions, such as ammonium, NH4+; hydroxide, OH−; or carbonate, CO32−). It also
- acid-base titration (chemical process)
titration: …the sample and titrant, include: acid-base titrations, precipitation titrations, complex-formation titrations, and oxidation-reduction (redox) titrations. In acid-base titration (i.e., the titration of an acid with a base, or vice versa), the indicator is a substance that can exist in two forms, an acid form and a basic form, which differ…
- acid-copper lead (alloy)
lead processing: The metal and its alloys: Acid lead, made by adding copper to fully refined lead, differs from chemical lead primarily in its higher bismuth content.
- Acidalia Planitia (region, Mars)
Mars: Sparsely cratered plains: These include Chryse Planitia and Acidalia Planitia (centered on 30° W longitude), Amazonis Planitia (160° W), and Utopia Planitia (250° W). The only significant relief in this huge area is a large ancient impact basin, informally called the Utopia basin (40° N, 250° W).
- Acidithiobacillus ferrooxidans (bacterium)
bacteria: pH: …sulfide deposits are attacked by A. ferrooxidans to generate sulfuric acid, which lowers the pH to 2.0 or even 0.7. However, acid tolerance of A. ferrooxidans applies only to sulfuric acid, since these bacteria die when exposed to equivalent concentrations of other acids such as hydrochloric acid. Many bacteria cannot…
- acidity (chemistry)
buffer: …the ionization constant of acetic acid and the expressions in brackets are the concentrations of the respective substances. The hydrogen ion concentration of the buffer solution is dependent on the relative amounts of acetic acid and acetate ion (or sodium acetate) present, known as the buffer ratio. The addition of…
- acidity exponent (chemistry)
acid–base reaction: Acid–base equilibria: …quantity pKa, sometimes called the acidity exponent, and defined by the relation pKa = −log10Ka. Values of pKa are generally of a more convenient magnitude.
- acidity function (chemistry)
acid–base reaction: Concentrated aqueous acids: …is commonly measured by the acidity function, H0, a quantity measured by the effect of the solvent on a basic indicator I. It is defined by H0 + pKih+ − log10 [IH+]/[I] and becomes equal to the pH in dilute solution. The acidity function H0 frequently is found to be…
- acidophile (biology)
extremophile: …organisms may be described as acidophilic (optimal growth between pH 1 and pH 5); alkaliphilic (optimal growth above pH 9); halophilic (optimal growth in environments with high concentrations of salt); thermophilic (optimal growth between 60 and 80 °C [140 and 176 °F]); hyperthermophilic (optimal growth above 80 °C [176 °F]);…
- acidophilic organism (biology)
extremophile: …organisms may be described as acidophilic (optimal growth between pH 1 and pH 5); alkaliphilic (optimal growth above pH 9); halophilic (optimal growth in environments with high concentrations of salt); thermophilic (optimal growth between 60 and 80 °C [140 and 176 °F]); hyperthermophilic (optimal growth above 80 °C [176 °F]);…
- acidosis (pathology)
acidosis, abnormally high level of acidity, or low level of alkalinity, in the body fluids, including the blood. There are two primary types of acidosis: respiratory acidosis and metabolic acidosis. Respiratory acidosis results from inadequate excretion of carbon dioxide from the lungs. This may be
- acids and bases, proton theory of (chemistry)
Brønsted-Lowry theory, a theory, introduced independently in 1923 by the Danish chemist Johannes Nicolaus Brønsted and the English chemist Thomas Martin Lowry, stating that any compound that can transfer a proton to any other compound is an acid, and the compound that accepts the proton is a base.
- Acier Noir (typeface)
Cassandre: …he designed two other typefaces, Acier Noir (1935) and Piegnot (1937). In 1939 he abandoned poster art and henceforth devoted himself to designing stage sets and to painting.
- Acier, Michel Victor (French sculptor)
pottery: Porcelain: …by the figure modelling of Michel Victor Acier, who came to the factory to share the position of Modellmeister with Kändler in 1764. From 1774 to 1814 the Neoclassical style was increasingly used, and the designs of Sèvres and of Wedgwood (Wedgwoodarbeit) were copied.
- Aciéries Réunies de Burbach-Eich-Dudelange (Luxembourger company)
Luxembourg: Manufacturing and trade: …the late 1970s ARBED (Aciéries Réunies de Burbach-Eich-Dudelange) SA was Luxembourg’s only remaining steelmaker. In 2001 ARBED merged with the Spanish company Aceralia and the French company Usinor to form Arcelor, which subsequently joined Mittal to create ArcelorMittal, the world’s largest steel company at the time of its formation…
- Acilia Repetundarum, Lex (Roman law)
epigraphy: Ancient Rome: …bce; pieces of the laws Lex Acilia Repetundarum (123 bce) and Lex Agraria (111 bce) were found in the 16th century on opposite sides of what was once a large bronze tablet; the local laws of the town of Bantia (on the borderlands of Lucania and Apulia in southern Italy)…
- Acilius Glabrio (Roman consul)
Marcus Porcius Cato: …Cato served with distinction under Manius Acilius Glabrio at Thermopylae in the war against the Seleucid king Antiochus III. Shortly thereafter he included Glabrio in his denunciation of the supporters of the Scipios. He then attacked Lucius Scipio and Scipio Africanus the Elder and broke their political influence. This success…
- acinar cell (anatomy)
pharmaceutical industry: Isolation of insulin: …destroyed by enzymes from the acinar cells. By this time Banting had enlisted the support of Charles H. Best, a fourth-year medical student. Together they tied off the pancreatic ducts through which acinar cells release the digestive enzymes. This insult caused the acinar cells to die. Subsequently, the remainder of…
- Acinipo (Spain)
Ronda, town, Málaga provincia (province), in the Andalusia comunidad autónoma (autonomous community), southern Spain. It lies in the Ronda Mountains west of Málaga city. The town is situated on two hills divided by a deep ravine (El Tajo de Ronda) containing the Grande River, which is an affluent
- Acinonyx (mammal)
feline: Evolution and classification: Acinonychinae Genus Acinonyx (cheetah) 1 almost exclusively African species. Assorted ReferencesAmazon Rain Forestclassification and characteristics
- Acinonyx jubatus (mammal)
cheetah, (Acinonyx jubatus), one of the world’s most-recognizable cats, known especially for its speed. Cheetahs’ sprints have been measured at a maximum of 114 km (71 miles) per hour, and they routinely reach velocities of 80–100 km per hour while pursuing prey. Nearly all the cheetahs remaining
- Ačinsk (Russia)
Achinsk, city, Krasnoyarsk kray (region), south-central Russia. It lies along the Chulym River, which is a tributary of the Ob. It was founded in 1621 and chartered in 1782. Important as a river-road transfer point until rail lines were constructed, it gained economic importance when an alumina
- acinus (anatomy)
respiratory disease: Morphological classification of respiratory disease: …terminal bronchiole opens into an acinus, so called because the structure resembles a cluster of grapes, and from this point onward the gas-exchanging portion of the lung is reached. The alveoli, or air sacs, which are divided into groups or lobules by fibrous partitions, or septa, are small hexagonal structures…
- Acipenser baerii (fish)
chondrostean: Distribution: The Baikal sturgeon (A. baerii) occurs in Lake Baikal and in nearby regions of Russia (Siberia), China, and Kazakhstan. A smaller species, the sterlet (A. ruthenus), inhabits the Black and Caspian seas. The starry
- Acipenser fulvescens (fish)
chondrostean: Distribution: The lake sturgeon of North America (A. fulvescens) occurs in the Mississippi River valley, in Lake Huron, and northward into Canada. The white, Oregon, or Sacramento sturgeon (A. transmontanus) inhabits the waters of the Pacific coast of North America from California to
- Acipenser guldenstadtii (fish)
sturgeon: Distribution: The Russian sturgeon, A. guldenstadtii, is one of the most valuable species inhabiting the rivers of Russia and occurs eastward to Lake Baikal. It is about the same size as the common sturgeon and is found particularly in the rivers feeding the Black and Caspian seas.…
- Acipenser huso (fish)
hausen, large species of sturgeon
- Acipenser oxyrinchus (fish)
chondrostean: Distribution: A closely related form (A. oxyrinchus) is found along the east coast of North America from the St. Lawrence River to the Gulf of Mexico. The Baikal sturgeon (A. baerii) occurs in Lake Baikal and in nearby regions of Russia (Siberia), China, and Kazakhstan. A
- Acipenser ruthenus (fish)
caviar: …the golden eggs of the sterlet, was formerly reserved for the table of the tsar; more recently it found its way to the tables of Soviet dignitaries and that of the shah of Iran. Lesser grades of caviar, made from broken or immature eggs, are more heavily salted and compressed.…
- Acipenser sinensis (fish)
sturgeon: Conservation status: The Chinese sturgeon is thought to be the species most at risk, because its population declined nearly 98 percent between 1973 and 2010. The species decline has been associated with water pollution in the Yangtze and dam construction that has blocked access to or changed the…
- Acipenser stellatus (fish)
chondrostean: Distribution: The starry sturgeon (A. stellatus) occurs in rivers leading to the Black Sea, the Sea of Azov, and the Caspian Sea. The lake sturgeon of North America (A. fulvescens) occurs in the Mississippi River valley, in Lake Huron, and northward into Canada. The white, Oregon, or…
- Acipenser sturio (fish)
chondrostean: Distribution: The common sturgeon (Acipenser sturio; also known as the Atlantic, or Baltic, sturgeon) is found along the European coast from Norway to the Mediterranean Sea. A closely related form (A. oxyrinchus) is found along the east coast of North America from the St. Lawrence River to…
- Acipenser transmontanus (fish)
chondrostean: Distribution: …Oregon, or Sacramento sturgeon (A. transmontanus) inhabits the waters of the Pacific coast of North America from California to Alaska. The shovelnose sturgeons (genus Scaphirhynchus) occur in the Mississippi drainage system of North America. The Aral Sea shovelnose sturgeons (Pseudoscaphirhynchus) are found in rivers that drain into the
- Acipenseridae (fish)
sturgeon, (family Acipenseridae), any of about 29 species of fishes of the family Acipenseridae (subclass Chondrostei), native to temperate waters of the Northern Hemisphere. Most species live in the ocean and ascend rivers (possibly once in several years) to spawn in spring or summer; a few others
- Acipenseriformes (fish order)
fish: Annotated classification: Order Acipenseriformes (sturgeons and paddlefishes) Almost no internal ossification; scales as large scutes in isolated rows (Acipenseridae); snout enlarged and tactile (Polyodontidae); median fins chondrostean in having more fin rays than basal elements; tail heterocercal. Length (sturgeons) up to 6 metres (roughly 20 feet), weight to…
- Acireale (Italy)
Acireale, town and episcopal see, eastern Sicily, Italy, on terraces above the Ionian Sea at the foot of Mount Etna, 7 miles (11 km) northeast of Catania. Known as Aquilia by the Romans, the town was called Reale by Philip IV of Spain in 1642. The first part of its name is derived from the ancient
- Acis (Greek mythology)
Acis, in the Greek mythology of Ovid, the son of Faunus (Pan) and the nymph Symaethis. He was a beautiful shepherd of Sicily, the lover of the Nereid Galatea. His rival, Polyphemus the Cyclops, surprised them together and crushed him to pieces with a rock. His blood, gushing forth from beneath, was
- Acis and Galatea (serenata by Handel)
serenata: …genre is Handel’s pastoral serenata Acis and Galatea (c. 1718).
- Acis et Galatée (ballet by Fokine)
Michel Fokine: …performance by his pupils, was Acis et Galatée, based on an ancient Sicilian legend. Fokine’s enthusiasm for antiquity owed nothing in origin to the “free dance” ideas of the American dancer Isadora Duncan, although her appearance in Russia in 1905 greatly consolidated his own views. In 1905 he also composed…
- Acis in Oxford (work by Finch)
Robert Finch: …as did a later work, Acis in Oxford (1961), a series of meditations inspired by a performance of G.F. Handel’s dramatic oratorio Acis and Galatea. Dover Beach Revisited (1961), treating the World War II evacuation of Dunkirk and issues of faith, contains 11 variations on Matthew Arnold’s poem. In another…
- Acisoma attenboroughi (dragonfly)
10 Organisms Named for David Attenborough: Attenborough’s pintail: • What: striking blue and black dragonfly with intricately veined wings. An agile flier, the insect is common in rice paddies and near bodies of fresh water in its native range.
- aCJD
Creutzfeldt-Jakob disease: Types: acquired (aCJD). Both sCJD and aCJD may be further divided into subtypes. The most common sCJD subtype is sCJDMM1. Subtypes of aCJD include iatrogenic (iCJD) and variant (vCJD) forms of the disease (kuru is sometimes considered a third subtype of aCJD).
- AcK (isotope)
francium: …an isotope of francium (francium-223) that was formerly called actinium K (AcK) and is a member of the actinium decay series. Though it is the longest-lived isotope of francium, francium-223 has a half-life of only 22 minutes. Thirty-four isotopes of francium with masses between 199 and 232 have been…
- Ack libertas, tu ädla tingh (work by Wivallius)
Lars Wivallius: …1632 and translates as “Ah, Liberty, Thou Noble Thing”) and love of nature (most notably the majestic “Klagovisa över denna torra och kalla vår” [1642; “Dirge over This Dry and Cold Spring”], in which the poet laments the season that he encountered upon his release from Kajaneborg).
- ackee (plant)
ackee, (Blighia sapida), tree of the soapberry family (Sapindaceae) native to West Africa, widely cultivated throughout tropical and subtropical regions for its edible fruit. Ackee and salt fish is a popular dish in the Caribbean and is the national dish of Jamaica. Taken to the Caribbean area with
- Acker, Kathy (American author)
Kathy Acker was an American novelist whose writing style and subject matter reflect the so-called punk sensibility that emerged in the 1970s. Acker studied classics at Brandeis University and the University of California, San Diego. Her early employment ranged from clerical work to performing in
- Ackerley, J.R. (British writer and editor)
J.R. Ackerley was a British novelist, dramatist, poet, and magazine editor known for his eccentricity. Ackerley’s education was interrupted by his service in World War I, during which he was captured and imprisoned for eight months in Germany. He graduated from Magdalen College, Cambridge, in 1921.
- Ackerley, Joe Randolph (British writer and editor)
J.R. Ackerley was a British novelist, dramatist, poet, and magazine editor known for his eccentricity. Ackerley’s education was interrupted by his service in World War I, during which he was captured and imprisoned for eight months in Germany. He graduated from Magdalen College, Cambridge, in 1921.
- Ackerman, Diane (American author)
Diane Ackerman is an American writer whose works often reflect her interest in natural science. Ackerman was educated at Pennsylvania State University (B.A., 1970) and Cornell University, Ithaca, N.Y. (M.F.A., 1973; M.A., 1976; Ph.D., 1978). From 1980 to 1983 she taught English at the University of
- Ackerman, Edward A. (American geographer)
geography: Geography as a science: a new research agenda: …well to the war effort: Edward A. Ackerman, a professor of geography at the University of Chicago from 1948 to 1955 (and later head of the Carnegie Foundation), claimed that those working in the U.S. government’s intelligence service had only a weak understanding of their material and portrayed them as…
- Ackermann aus Böhmen, Der (work by Johannes von Tepl)
Johannes von Tepl: 1400; Death and the Ploughman), the first important prose work in the German language.
- Ackermann system (mechanics)
truck: Steering: Steering is always by the Ackermann system, which provides a kingpin for each front wheel. Maximum cramp angle of the front wheels is about 35 degrees. The minimum turning radius is dependent on the wheelbase. A few vehicles have been built with two steering axles in the front.
- Ackermann, Haider (French fashion designer)
Timothée Chalamet: Red carpet fashion: …has favored such designers as Haider Ackermann, Alexander McQueen, and Stella McCartney. A few of Chalamet’s more daring looks included a Virgil Abloh sequin harness that he sported at the 2019 Golden Globe Awards and a cropped shimmering jacket from Louis Vuitton’s women’s wear line, under which he wore nothing,…
- Ackermann, Konrad Ernst (German actor and manager)
Konrad Ernst Ackermann was an actor-manager who was a leading figure in the development of German theatre. Conflicting accounts exist of Ackermann’s early adult years. He was probably not a trained scientist and surgeon, as has been widely reported, but was instead a soldier—and later an officer—in
- Ackermann, Louise-Victorine (French poet)
Louise-Victorine Ackermann was a French poet who is best-known for works characterized by a deep sense of pessimism. Educated by her father in the philosophy of the Encyclopédistes, she traveled to Berlin in 1838 to study German and there married (1843) Paul Ackermann, an Alsatian philologist. Two
- Ackermann, Wilhelm (German logician)
history of logic: Propositional and predicate logic: …Theoretical Logic”) by Hilbert and Wilhelm Ackermann.
- Ackoli (work by Holub)
Miroslav Holub: … (1963; “The So-Called Heart”), and Ačkoli (1969; Although).
- Ackroyd, Peter (British author, biographer, critic and scholar)
Peter Ackroyd is a British novelist, critic, biographer, and scholar whose technically innovative novels present an unconventional view of history. Ackroyd graduated from Clare College, Cambridge (M.A., 1971), and then attended Yale University for two years. In 1973 he returned to England and