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  • atole (beverage)

    Atole, a hot Mexican beverage typically made from masa (corn dough) or masa harina (dough flour), water, and spices. Sometimes it is made with oatmeal, rice, barley, or wheat instead of masa. The drink is commonly prepared by toasting the masa on a griddle before mixing in water, sugar, vanilla,

  • Atoleiros, Battle of (Portuguese history)

    Saint Nuno Álvares Pereira: …defeated the Castilians in the Battle of Atoleiros (April 6, 1384). Further brilliant and heroic actions as a field commander won him the office of constable of the kingdom in 1385.

  • atoll (coral reef)

    Atoll, coral reef enclosing a lagoon. Atolls consist of ribbons of reef that may not always be circular but whose broad configuration is a closed shape up to dozens of kilometres across, enclosing a lagoon that may be approximately 50 metres (160 feet) deep or more. Most of the reef itself is a

  • Atoll (missile)

    rocket and missile system: Air-to-air: …primitive semiactive radar missile, the AA-2 Atoll, an infrared missile closely modeled after the Sidewinder, and the AA-3 Anab, a long-range, semiactive radar-homing missile carried by air-defense fighters. The AA-5 Ash was a large, medium-range radar-guided missile, while the AA-6 Acrid was similar to the Anab but larger and with…

  • atom (matter)

    Atom, smallest unit into which matter can be divided without the release of electrically charged particles. It also is the smallest unit of matter that has the characteristic properties of a chemical element. As such, the atom is the basic building block of chemistry. Most of the atom is empty

  • atom bomb (fission device)

    Atomic bomb, weapon with great explosive power that results from the sudden release of energy upon the splitting, or fission, of the nuclei of a heavy element such as plutonium or uranium. When a neutron strikes the nucleus of an atom of the isotopes uranium-235 or plutonium-239, it causes that

  • atom buncher (device)

    spectroscopy: Noble gas detection: …the chance that a krypton atom will be in the laser beam when the beam is pulsed through the apparatus. The atom buncher consists of a surface held near the temperature of liquid helium to condense the krypton atoms and another pulsed laser to heat the surface just prior to…

  • atom economy (chemistry)

    green chemistry: Atom economy: Of these principles, “atom economy,” originally suggested by American chemist Barry Trost in 1973, became a central concept among green chemistry researchers. Atom economy was designed to overcome the limitations of the traditional concept of “yield,” the amount of final products, which was…

  • atom laser (physics)

    atomic physics: …trap to form an “atom laser” analogous to the coherent beam of photons in a conventional laser. The atom laser is still in an early stage of development, but it has the potential to become a key element of future technologies for the fabrication of microelectronic and other nanoscale…

  • Atom Piece (sculpture by Moore)

    Henry Moore: Later years: Although the University of Chicago’s Atom Piece, with its mushroom-cloud formation at the top, commemorates the splitting of the atom, the sculpture is also closely related to other large abstract sculptures of the 1960s: Knife-Edge Two-Piece (1962), Locking Piece (1963–64), Three-Way Piece No. 1: Points (1964), and Three-Piece Sculpture No.…

  • atom probe (instrument)

    field-emission microscope: …the field-ion microscope is the atom probe. In this instrument, individual atoms are removed from the tip by pulsing the electric field. The atoms pass through a time-of-flight spectrometer, which measures their energy and charge-to-mass ratio. In this way the chemical nature of each atom in the field-ion image may…

  • atom, central (molecule)

    chemical bonding: Hypervalence: …more atoms attached to a central atom than can be accommodated by an octet of electrons. An example is sulfur hexafluoride, SF6, for which writing a Lewis structure with six S―F bonds requires that at least 12 electrons be present around the sulfur atom:

  • Atom, The (American comic strip superhero DC Comics)

    The Atom, American comic strip superhero created for DC Comics by writer Bill O’Connor and artist Ben Flinton. The character first appeared in All-American Comics no. 19 (October 1940). Al Pratt, the first hero to adopt the mantle of the Atom, was a college student tired of being teased about his

  • Atombombe und die Zukunft des Menschen, Die (work by Jaspers)

    Karl Jaspers: Postwar development of thought: …die Zukunft des Menschen (The Future of Mankind, 1961). The aim of this political world union would not be absolute sovereignty but rather world confederation, in which the various entities could live and communicate in freedom and peace.

  • Atomic Age (historical era)

    material culture: …beginning of the third great revolution in material culture and culture as a whole.

  • Atomic Annie (nuclear device)

    cannon: …shells; it was called an atomic cannon. Similar weapons were displayed by the U.S.S.R. in 1957. In later years, atomic explosives were fitted into shells small enough to be fired in standard artillery. See artillery.

  • Atomic Arrangement in Glass, The (work by Zachariasen)

    industrial glass: Science in glassmaking: Zachariasen published The Atomic Arrangement in Glass, a classic paper that had perhaps the most influence of any published work on glass science. Zachariasen’s work placed the understanding of glass structure and its relationship to composition on its modern footing. The principles of his atomic structure theory…

  • atomic beam

    spectroscopy: Methods: …his collaborators, using molecular and atomic beams. A beam focused by magnets in the absence of a radio-frequency field was defocused and lost when atoms were induced to make transitions to other states. The radio-frequency or microwave spectrum was taken by measuring the number of atoms that remained focused in…

  • Atomic Blonde (film by Leitch [2017])

    John Goodman: Film career: …a Time in Venice, and Atomic Blonde. His later movies included Captive State (2019), in which aliens have colonized Earth and face a resistance movement.

  • atomic bomb (fission device)

    Atomic bomb, weapon with great explosive power that results from the sudden release of energy upon the splitting, or fission, of the nuclei of a heavy element such as plutonium or uranium. When a neutron strikes the nucleus of an atom of the isotopes uranium-235 or plutonium-239, it causes that

  • Atomic Bomb Casualty Commission (research facility)

    Hiroshima: …Casualty Commission (since 1975 the Radiation Effects Research Foundation) began to conduct medical and biological research on the effects of radiation in Hiroshima. A number of public hospitals and private clinics give free treatment to victims of the atomic bombing (hibakusha). Hiroshima Castle, destroyed in the bombing, was restored in…

  • Atomic Bomb Dome (dome, Hiroshima, Japan)

    Hiroshima: Atomic Bomb Dome (Genbaku dōmu), which was designated a UNESCO World Heritage site in 1996, is the remains of one of the few buildings not obliterated by the blast. Pop. (2015) 1,194,034; (2018 est.) 1,199,252.

  • atomic cannon (nuclear device)

    cannon: …shells; it was called an atomic cannon. Similar weapons were displayed by the U.S.S.R. in 1957. In later years, atomic explosives were fitted into shells small enough to be fired in standard artillery. See artillery.

  • atomic clock (instrument)

    Atomic clock, type of clock that uses certain resonance frequencies of atoms (usually cesium or rubidium) to keep time with extreme accuracy. The electronic components of atomic clocks are regulated by the frequency of the microwave electromagnetic radiation. Only when this radiation is maintained

  • atomic diamagnetism (physics)

    superfluidity: Theoretical explanation of superfluidity: …for example, the phenomenon of atomic diamagnetism. Similarly, a single atom (or molecule) placed in a ring-shaped container is allowed by quantum mechanics to travel around the ring with only certain definite velocities, including zero. In an ordinary liquid such as water, the thermal disorder ensures that the atoms (or…

  • atomic emission spectroscopy

    chemical analysis: Luminescence: …emitted radiation, the method is atomic emission spectrometry. If a chemical reaction is used to initiate the luminescence, the technique is chemiluminescence; if an electrochemical reaction causes the luminescence, it is electrochemiluminescence.

  • atomic energy

    Nuclear energy, energy that is released in significant amounts in processes that affect atomic nuclei, the dense cores of atoms. It is distinct from the energy of other atomic phenomena such as ordinary chemical reactions, which involve only the orbital electrons of atoms. One method of releasing

  • Atomic Energy Act (United States [1954])

    nuclear weapon: Origins of the Super: The Atomic Energy Act, signed by President Truman on August 1, 1946, established the Atomic Energy Commission (AEC), replacing the Manhattan Engineer District, and gave it civilian authority over all aspects of atomic energy, including oversight of nuclear warhead research, development, testing, and production.

  • Atomic Energy Commission (French organization)

    nuclear weapon: France: …October 18, 1945, the French Atomic Energy Commission (Commissariat à l’Énergie Atomique; CEA) was established by Gen. Charles de Gaulle with the objective of exploiting the scientific, industrial, and military potential of atomic energy. The military application of atomic energy did not begin until 1951. In July 1952 the National…

  • Atomic Energy Commission (UN)

    United Nations: Arms control and disarmament: …Assembly in 1946 created the Atomic Energy Commission to assist in the urgent consideration of the control of atomic energy and in the reduction of atomic weapons. The United States promoted the Baruch Plan, which proposed the elimination of existing stockpiles of atomic bombs only after a system of international…

  • Atomic Energy Commission (United States organization)

    Atomic Energy Commission, U.S. federal civilian agency established by the Atomic Energy Act, which was signed into law by President Harry S. Truman on Aug. 1, 1946, to control the development and production of nuclear weapons and to direct the research and development of peaceful uses of nuclear

  • Atomic Energy Organization of Iran

    Iran: Power: The Atomic Energy Organization (AEO) of Iran was established in 1973 to construct a network of more than 20 nuclear power plants. By 1978 two 1,200-megawatt reactors near Būshehr on the Persian Gulf were near completion and were scheduled to begin operation early in 1980, but…

  • atomic fact (philosophy)

    Logical Atomism: …(an atomic proposition) and an atomic fact; thus, for each atomic fact there is a corresponding atomic proposition. An atomic proposition is one that asserts that a certain thing has a certain quality (e.g.: “This is red.”). An atomic fact is the simplest kind of fact and consists in the…

  • atomic fission (physics)

    thermonuclear warhead: Basic two-stage design: …a two-stage design, featuring a fission or boosted-fission primary (also called the trigger) and a physically separate component called the secondary. Both primary and secondary are contained within an outer metal case. Radiation from the fission explosion of the primary is contained and used to transfer energy to compress and…

  • atomic fission (physics)

    Nuclear fission, subdivision of a heavy atomic nucleus, such as that of uranium or plutonium, into two fragments of roughly equal mass. The process is accompanied by the release of a large amount of energy. In nuclear fission the nucleus of an atom breaks up into two lighter nuclei. The process may

  • atomic fluorescence (physics)

    chemical analysis: Luminescence: …gaseous atoms, it is termed atomic fluorescence.

  • atomic fluorescence spectrometry (chemistry)

    spectrochemical analysis: Atomic fluorescence spectrometry makes use of the same basic instrumental components as atomic absorption spectrometry; however, it measures the intensity of the light emitted by atoms that have been excited from their ground state by the absorption of light of shorter wavelength than that emitted.…

  • atomic fluorescence spectroscopy (chemistry)

    spectrochemical analysis: Atomic fluorescence spectrometry makes use of the same basic instrumental components as atomic absorption spectrometry; however, it measures the intensity of the light emitted by atoms that have been excited from their ground state by the absorption of light of shorter wavelength than that emitted.…

  • atomic force microscopy (physics)

    surface analysis: Atomic force microscopy: Atomic force microscopy profiles a sample by dragging an atomically sharp (i.e., only a few atoms wide) stylus across the surface and measuring the force between the stylus and the surface. The resulting signal can be translated into a description of the…

  • atomic formula (logic)

    Stanislao Cannizzaro: A single system of atomic formulas: In his 1858 pamphlet, Cannizzaro showed that a complete return to the ideas of Avogadro could be used to construct a consistent and robust theoretical structure that fit nearly all of the available empirical evidence. The few remaining anomalies, he argued, could easily…

  • atomic fusion (physics)

    Nuclear fusion, process by which nuclear reactions between light elements form heavier elements (up to iron). In cases where the interacting nuclei belong to elements with low atomic numbers (e.g., hydrogen [atomic number 1] or its isotopes deuterium and tritium), substantial amounts of energy are

  • atomic hydrogen maser

    maser: Gas masers: …frequency or time is the atomic hydrogen maser introduced by American scientists N.F. Ramsey, H.M. Goldenberg, and D. Kleppner in 1960. Its output is a radio wave whose frequency of 1,420,405,751.786 hertz (cycles per second) is reproducible with an accuracy of one part in 30 × 1012. A clock controlled…

  • atomic hypothesis (philosophy)

    Atomism, any doctrine that explains complex phenomena in terms of aggregates of fixed particles or units. This philosophy has found its most successful application in natural science: according to the atomistic view, the material universe is composed of minute particles, which are considered to be

  • atomic layer epitaxy (crystallography)

    epitaxy: Atomic layer epitaxy is based on introducing one gas that will absorb only a single atomic layer on the surface and following it with another gas that reacts with the preceding layer.

  • atomic mass (physics)

    Atomic mass, the quantity of matter contained in an atom of an element. It is expressed as a multiple of one-twelfth the mass of the carbon-12 atom, 1.992646547 × 10−23 gram, which is assigned an atomic mass of 12 units. In this scale 1 atomic mass unit (amu) corresponds to 1.660539040 × 10−24

  • atomic mass number (physics)

    Mass number, in nuclear physics, the sum of the numbers of protons and neutrons present in the nucleus of an atom. The mass number is commonly cited in distinguishing among the isotopes of an element, all of which have the same atomic number (number of protons) and are represented by the same

  • atomic mass unit (physics)

    atom: Atomic mass and isotopes: …measured in terms of the atomic mass unit, which is defined to be 112 of the mass of an atom of carbon-12, or 1.660538921 × 10−24 gram. The mass of an atom consists of the mass of the nucleus plus that of the electrons, so the atomic mass unit is…

  • atomic model

    atom: Models of atomic structure: J.J. Thomson’s discovery of the negatively charged electron had raised theoretical problems for physicists as early as 1897, because atoms as a whole are electrically neutral. Where was the neutralizing positive charge and what held it in place? Between 1903 and 1907 Thomson…

  • atomic moment (physics)

    atom: Bohr’s shell model: …to the orientation of their magnetic moments. In their experiment Stern and Gerlach found only two deflections, not the continuous distribution of deflections that would have been seen if the magnetic moment had been oriented in any direction. Thus, it was determined that the magnetic moment and the angular momentum…

  • atomic nucleus (physics)

    atom: The nucleus: The primary constituents of the nucleus are the proton and the neutron, which have approximately equal mass and are much more massive than the electron. For reference, the accepted mass of the proton is 1.672621777 × 10−24 gram, while that of the…

  • atomic number (physics)

    Atomic number, the number of a chemical element in the periodic system, whereby the elements are arranged in order of increasing number of protons in the nucleus. Accordingly, the number of protons, which is always equal to the number of electrons in the neutral atom, is also the atomic number. An

  • atomic orbital (chemistry and physics)

    Orbital, in chemistry and physics, a mathematical expression, called a wave function, that describes properties characteristic of no more than two electrons in the vicinity of an atomic nucleus or of a system of nuclei as in a molecule. An orbital often is depicted as a three-dimensional region

  • atomic particle (physics)

    particle accelerator: …beam of fast-moving, electrically charged atomic or subatomic particles. Physicists use accelerators in fundamental research on the structure of nuclei, the nature of nuclear forces, and the properties of nuclei not found in nature, as in the transuranium elements and other unstable elements. Accelerators are also used for radioisotope production,…

  • atomic physics

    Atomic physics, the scientific study of the structure of the atom, its energy states, and its interactions with other particles and with electric and magnetic fields. Atomic physics has proved to be a spectacularly successful application of quantum mechanics, which is one of the cornerstones of

  • atomic polarization (physics)

    liquid: Speed of sound and electric properties: The second effect, atomic polarization, arises because there is a relative change in the mean positions of the atomic nuclei within the molecules. This generally small effect is observed at radio frequencies but not at optical, and so it is missing from the refractive index. The third effect,…

  • atomic power

    Nuclear energy, energy that is released in significant amounts in processes that affect atomic nuclei, the dense cores of atoms. It is distinct from the energy of other atomic phenomena such as ordinary chemical reactions, which involve only the orbital electrons of atoms. One method of releasing

  • atomic proposition (philosophy)

    Logical Atomism: …an “atom” of language (an atomic proposition) and an atomic fact; thus, for each atomic fact there is a corresponding atomic proposition. An atomic proposition is one that asserts that a certain thing has a certain quality (e.g.: “This is red.”). An atomic fact is the simplest kind of fact…

  • atomic radius (physics)

    Atomic radius, half the distance between the nuclei of identical neighbouring atoms in the solid form of an element. An atom has no rigid spherical boundary, but it may be thought of as a tiny, dense positive nucleus surrounded by a diffuse negative cloud of electrons. The value of atomic radii

  • Atomic Research Laboratory (United States history)

    Manhattan Project, U.S. government research project (1942–45) that produced the first atomic bombs. American scientists, many of them refugees from fascist regimes in Europe, took steps in 1939 to organize a project to exploit the newly recognized fission process for military purposes. The first

  • Atomic Rooster (British rock group)

    Emerson, Lake & Palmer: … (1968–69); and Palmer had cofounded Atomic Rooster (1969–70). ELP made synthesizer keyboards rather than guitars the centrepiece of its sound and developed an eclectic and innovative style blending classical music, jazz, blues, electronic music (then still a novelty), and

  • Atomic Scientists, Bulletin of the (American magazine)

    Harrison Brown: …editor in chief for the Bulletin of the Atomic Scientists from 1985 until his death.

  • atomic second

    spectroscopy: Methods: One second is defined as the time it takes for the cesium frequency to oscillate 9,192,631,770 times. Such atomic clocks have a longer-term uncertainty in their frequency that is less than one part in 1013. Measurement of time intervals based on the cesium atom’s oscillations are…

  • atomic sentence (logic)

    metalogic: Syntax and semantics: …as forming the simple (atomic) sentences, and (3) a set of inductive clauses—inductive inasmuch as they stipulate that natural combinations of given sentences formed by such logical connectives as the disjunction “or,” which is symbolized “∨”; “not,” symbolized “∼”; and “for all ,” symbolized “(∀),” are again sentences. [“(∀)”…

  • atomic size (physics)

    Atomic radius, half the distance between the nuclei of identical neighbouring atoms in the solid form of an element. An atom has no rigid spherical boundary, but it may be thought of as a tiny, dense positive nucleus surrounded by a diffuse negative cloud of electrons. The value of atomic radii

  • atomic slip (crystals)

    Slip, in engineering and physics, sliding displacement along a plane of one part of a crystal relative to the rest of the crystal under the action of shearing forces—that is, forces acting parallel to that plane. Much of the permanent, or plastic, deformation of materials under stress is the result

  • atomic spectrum (physics)

    spectroscopy: Basic atomic structure: The emission and absorption spectra of the elements depend on the electronic structure of the atom. An atom consists of a number of negatively charged electrons bound to a nucleus containing an equal number of positively charged protons. The nucleus

  • atomic structure (matter)

    Atom, smallest unit into which matter can be divided without the release of electrically charged particles. It also is the smallest unit of matter that has the characteristic properties of a chemical element. As such, the atom is the basic building block of chemistry. Most of the atom is empty

  • atomic theory (physics)

    Atomic theory, ancient philosophical speculation that all things can be accounted for by innumerable combinations of hard, small, indivisible particles (called atoms) of various sizes but of the same basic material; or the modern scientific theory of matter according to which the chemical elements

  • atomic time (physics)

    Atomic time, timescale generated by atomic clocks, which furnish time more accurately than was possible with previous astronomical means (measurements of the rotation of the Earth and its revolution about the Sun). International Atomic Time (TAI) is based on a system consisting of about 270

  • atomic vapour laser isotope separation (physics)

    isotope: Photochemical enrichment methods: In atomic vapour laser isotope separation (AVLIS), the starting material is the element itself; in molecular laser isotope separation (MLIS), the starting material is a chemical compound containing the element. Ordinary light sources are not suitable for isotope separation because they emit a broad range of…

  • atomic warfare

    doomsday machine: …in the event of a nuclear attack on the country maintaining the device. The former type of device might automatically launch a large number of ICBMs (intercontinental ballistic missiles) when it detected a nuclear explosion or an imminent nuclear attack, whereas the latter might detonate several very large thermonuclear bombs…

  • atomic weapon

    Nuclear weapon, device designed to release energy in an explosive manner as a result of nuclear fission, nuclear fusion, or a combination of the two processes. Fission weapons are commonly referred to as atomic bombs. Fusion weapons are also referred to as thermonuclear bombs or, more commonly,

  • atomic weight (chemistry and physics)

    Atomic weight, ratio of the average mass of a chemical element’s atoms to some standard. Since 1961 the standard unit of atomic mass has been one-twelfth the mass of an atom of the isotope carbon-12. An isotope is one of two or more species of atoms of the same chemical element that have different

  • Atomico Ventures (investment fund)

    Niklas Zennström: Joost: …2006 Zennström and Friis founded Atomico Ventures, an investment fund that sought out European technology companies that had the potential to be successful in the global market. Niklas and his wife, Catherine, established Zennström Philanthropies in 2007 to support and engage with organizations in efforts to stop climate change and…

  • Atomised (novel by Houellebecq)

    Michel Houellebecq: …the United Kingdom and as The Elementary Particles in the United States. In it he presented two half brothers who were abandoned by their parents in childhood. Bruno is driven by an insatiable sexual appetite, while Michel, a scientist, avoids the issue of any attachment whatsoever by focusing his attention…

  • atomism (philosophy)

    Atomism, any doctrine that explains complex phenomena in terms of aggregates of fixed particles or units. This philosophy has found its most successful application in natural science: according to the atomistic view, the material universe is composed of minute particles, which are considered to be

  • Atomism, Logical (philosophy)

    Logical Atomism, theory, developed primarily by the British logician Bertrand Russell and the Austrian-born philosopher Ludwig Wittgenstein, proposing that language, like other phenomena, can be analyzed in terms of aggregates of fixed, irreducible units or elements. Logical Atomism supposes that

  • atomistic competition (economics)

    monopoly and competition: Concentration of sellers: …competing seller, economists speak of atomistic competition. A more common situation is that of oligopoly, in which the number of sellers is so few that the market share of each is large enough for even a modest change in price or output by one seller to have a perceptible effect…

  • Atomium (building, Brussels, Belgium)

    Brussels: Cultural life: …held and where the iconic Atomium, a structure built for that exhibition, still stands.

  • atomization (spectrochemical analysis)

    spectroscopy: RIS atomization methods: Because the RIS technique is limited to the study of free atoms or molecules in the gas phase, the analysis of solids and liquids requires a means for releasing atoms from the bulk material. A simple and effective system in which…

  • atomization (metallurgy)

    metallurgy: Processes: In other atomization processes, centrifugal force is used. The metal can be poured onto a spinning disk that breaks up the stream, or a spinning rod can be melted by an electric arc so that it throws off particles as it spins.

  • atomizer (device)

    e-cigarette: …in the cartridge, and the atomizer vaporizes the liquid, emitting it as a mist that the user inhales. Hence, e-cigarette use is commonly described as vaping, a term also used in reference to the use of similar devices, including vape pens and e-hookas.

  • atomoxetine (drug)

    attention-deficit/hyperactivity disorder: Treatment: …drug known as atomoxetine (Strattera®). Atomoxetine works by inhibiting the reuptake of norepinephrine from nerve terminals, thereby increasing the amount of the neurotransmitter available in the brain.

  • Atoms for Peace (musical group)

    Radiohead: …sang for the electronic-influenced group Atoms for Peace, which in 2013 released the intricately textured Amok, while Jonny Greenwood composed film soundtracks, among them Phantom Thread and You Were Never Really Here (both 2017).

  • Atoms for Peace speech (speech by Eisenhower)

    Atoms for Peace speech, speech delivered to the United Nations by U.S. Pres. Dwight D. Eisenhower on December 8, 1953 (see primary source document: Atoms for Peace). In this address, Eisenhower spelled out the necessity of repurposing existing nuclear weapons technology to peaceful ends, stating

  • Aton (Egyptian god)

    Aton, in ancient Egyptian religion, a sun god, depicted as the solar disk emitting rays terminating in human hands, whose worship briefly was the state religion. The pharaoh Akhenaton (reigned 1353–36 bce) returned to supremacy of the sun god, with the startling innovation that the Aton was to be

  • Aton Hymn (Egyptian religion)

    Aton Hymn, the most important surviving text relating to the singular worship of the Aton, a new religious ideology espoused by the ancient Egyptian king Akhenaton of the 18th dynasty. During his reign Akhenaton returned to the supremacy of the sun god, with the startling innovation that the Aton

  • atonality (music)

    Atonality, in music, the absence of functional harmony as a primary structural element. The reemergence of purely melodic-rhythmic forces as major determinants of musical form in the Expressionist works of Arnold Schoenberg and his school prior to World War I was a logical, perhaps inevitable

  • Atonement (film by Wright [2007])

    Atonement: An Academy Award-winning film version of the story appeared in 2007.

  • atonement (religion)

    Atonement, the process by which a person removes obstacles to his reconciliation with God. It is a recurring theme in the history of religion and theology. Rituals of expiation and satisfaction appear in most religions, whether primitive or developed, as the means by which the religious person

  • Atonement (novel by McEwan)

    Atonement, novel by Ian McEwan, published in 2001. An Academy Award-winning film version of the story appeared in 2007. The first part of the novel begins in the summer of 1935 as 13-year-old Briony Tallis attempts to direct her three cousins in a self-penned play to celebrate the homecoming of her

  • Atonement, Day of (Judaism)

    Yom Kippur, most solemn of Jewish religious holidays, observed on the 10th day of the lunar month of Tishri (in the course of September and October), when Jews seek to expiate their sins and achieve a reconciliation with God. Yom Kippur concludes the “10 days of repentance” that begin with Rosh

  • Atoni (people)

    Atoni, predominant people of Timor, easternmost of the Lesser Sunda Islands, Indonesia. They inhabit the central and western plains and mountains of the island and number about 530,000. Of Proto-Malay and Melanoid stock, they speak a Malayo-Polynesian dialect called Timorese. Atoni legend claims

  • atopic dermatitis (pathology)

    Atopic dermatitis, a type of dermatitis

  • atopic hypersensitivity (medicine)

    Atopy, type of hypersensitivity characterized by an immediate physiological reaction, with movement of fluid from the blood vessels into the tissues, upon exposure to an allergen. Atopy occurs mainly in persons with a familial tendency to allergic diseases; reaginic antibodies are found in the

  • Atopogale cubana (mammal)

    Cuba: Plant and animal life: Solenodons (Atopogale cubana), which are nearly extinct ratlike insectivores, are found only in the remotest eastern regions. Other mammals include hutias (edible rodents) and manatees, or sea cows, which inhabit river mouths. Several types of bats prey on mosquitoes and insects harmful to agriculture, and in…

  • atopy (medicine)

    Atopy, type of hypersensitivity characterized by an immediate physiological reaction, with movement of fluid from the blood vessels into the tissues, upon exposure to an allergen. Atopy occurs mainly in persons with a familial tendency to allergic diseases; reaginic antibodies are found in the

  • Atossa (Persian princess)

    Cyrus the Great: Cyrus’s conquests: …had at least one daughter, Atossa (who married her brother Cambyses), and possibly two others, but they played no role in history.

  • ATP (coenzyme)

    Adenosine triphosphate (ATP), energy-carrying molecule found in the cells of all living things. ATP captures chemical energy obtained from the breakdown of food molecules and releases it to fuel other cellular processes. Cells require chemical energy for three general types of tasks: to drive

  • ATP (international sports organization)

    tennis: The open era: …female players formed guilds—the men’s Association of Tennis Professionals (ATP) and the Women’s Tennis Association (WTA), which in 1986 became the Women’s International Tennis Association (WITA). Previous player unions had been ineffective, but the ATP showed itself a potent political force when the majority of its members boycotted Wimbledon in…

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