Alps: Plant and animal life: These distinctive mountain pastures—called alpages, from which both the names of the mountain system and the vegetational zone are derived—are found above the main and lateral valleys; the spread of invasive weeds, pollution from animal wastes, and erosion from ski-related development limit their carrying capacity. In the southern reaches…

alphorn, long horn played by Alpine herdsmen and villagers, sounded for intercommunication and at daily ceremonies and seasonal festivals. It is carved or bored in wood and overwound with birch bark. Some instruments are straight, reaching 12 feet (4 metres) in length; since the mid-19th century,

Alpenrhein River, the part of the Rhine River between the confluence of the Vorder- and Hinterrhein and its entry into Lake Constance. It is 63 miles (102 km) long. From Reichenau to Sargans it flows entirely within Swiss territory; for the next 19 miles (30 km) it forms the border between

An Alpine Symphony, Op. 64, symphonic poem by German composer Richard Strauss that musically re-creates a day’s mountain climb in the Bavarian Alps. It premiered on October 28, 1915. At the time he composed this piece, Strauss was living in the southern Bavarian town of Garmisch (now

Herb Alpert is an American trumpeter and music industry executive known for leading the band Herb Alpert & the Tijuana Brass and for cofounding A&M Records. Hit albums by Alpert, one of the best-selling instrumentalists of all time, helped A&M Records become an industry powerhouse. Alpert was the

Herb Alpert is an American trumpeter and music industry executive known for leading the band Herb Alpert & the Tijuana Brass and for cofounding A&M Records. Hit albums by Alpert, one of the best-selling instrumentalists of all time, helped A&M Records become an industry powerhouse. Alpert was the

Ram Dass was an American spiritual leader, psychologist, and writer who was influential in the New Age movement. Born Richard Alpert, he spent much of his early career developing a reputation as an academic psychologist. In the early 1960s, alongside Timothy Leary, he began to research psychedelic

Alpes, several small provinces set up by the Romans in the western Alps. Some time after the conquest of the Ligurian tribes in the area in 14 bc, Augustus established Alpes Maritimae (Maritime Alps) under a prefect (later a procurator), to guard the coastal road from Italy to southern France. Its

Alpes: Farther north, Alpes Graiae (Graian Alps), administered within changing borders, was organized by Claudius as a province that included the Swiss Valais. He founded a capital at Forum Claudii (perhaps present-day Aime, about 20 miles [32 km] from the Little Saint Bernard Pass, which the province was…

Alpes: Farther north, Alpes Graiae (Graian Alps), administered within changing borders, was organized by Claudius as a province that included the Swiss Valais. He founded a capital at Forum Claudii (perhaps present-day Aime, about 20 miles [32 km] from the Little Saint Bernard Pass, which the province was…

Alpes: Adjoining it was Alpes Cottiae (Cottian Alps), where Augustus installed Cottius, a native chieftain with Roman citizenship, as prefect. Claudius bestowed the title of king on Cottius’s son. After the king’s death, Nero organized the area as a province under a procurator. Its capital was Eburodunum (present-day Embrun),…

Dauphiné Alps, western spur of the Cottian Alps (q.v.) in southeastern France, lying between the Arc and Isère river valleys (north) and the upper Durance River valley (south). Many peaks rise to more than 10,000 feet (3,050 m), with Barre des Écrins (13,459 feet [4,102 m]) the highest. The

Alpes: Farther north, Alpes Graiae (Graian Alps), administered within changing borders, was organized by Claudius as a province that included the Swiss Valais. He founded a capital at Forum Claudii (perhaps present-day Aime, about 20 miles [32 km] from the Little Saint Bernard Pass, which the province was…

Lepontine Alps, segment of the Central Alps along the Italian–Swiss border, bounded by the Simplon Pass and Pennine Alps (west-southwest), the Upper Rhône and Vorderrhein river valleys (north), Splügen Pass (Italian Passo dello Spluga) and the Rhaetian Alps (east-northeast), and the Italian lake

Alpes: …in 14 bc, Augustus established Alpes Maritimae (Maritime Alps) under a prefect (later a procurator), to guard the coastal road from Italy to southern France. Its capital was Cemenelum (present-day Cimiez, near Nice), which developed into a prosperous municipality. It was joined to Pedo (present-day Borgo San Dalmazzo in Piedmont,…

Pennine Alps, segment of the central Alps along the Italian-Swiss border, bounded by the Great St. Bernard Pass and the Mont Blanc group (southwest), by the Upper Rhône Valley (north), by Simplon Pass and the Lepontine Alps (northeast), and by the Dora Baltea River valley (south). The highest point

Alpes: …Graiae was often combined with Alpes Poeninae (Pennine Alps), farther north and east, which guarded the Great Saint Bernard Pass. The administration of these northern Alpes seems to have fluctuated until Diocletian reorganized the whole provincial system.

Rhaetian Alps, segment of the Central Alps extending along the Italian-Swiss and Austrian-Swiss borders but lying mainly in Graubünden canton, eastern Switzerland. The mountains are bounded by the Lepontine Alps and Splügen Pass (west-southwest), the Hinterrhein River (west), the Lechtaler Alps

Provence–Alpes–Côte d’Azur: of Alpes-Maritimes, Hautes-Alpes, Alpes-de-Haute-Provence, Var, Bouches-du-Rhône, and Vaucluse. Provence–Alpes–Côte d’Azur is bounded by the régions of Occitanie to the west and Auvergne-Rhône-Alpes to the north. Other boundaries include Italy to the east and the Mediterranean Sea to the south.

Provence–Alpes–Côte d’Azur: … encompassing the southeastern départements of Alpes-Maritimes, Hautes-Alpes, Alpes-de-Haute-Provence, Var, Bouches-du-Rhône, and Vaucluse. Provence–Alpes–Côte d’Azur is bounded by the régions of Occitanie to the west and Auvergne-Rhône-Alpes to the north. Other boundaries include

John Knudsen Northrop: …Northrop produced the low-wing, aluminum Alpha, which was used to carry mail and passengers. In 1932 he formed the Northrop Corporation in partnership with Douglas, which used his multicellular wing structure on its famous DC-3 passenger and transport plane. In 1939 he founded Northrop Aircraft, Inc., and directed it until…

wolf: Gray wolf: …an adult breeding pair (the alpha male and alpha female) and their offspring of various ages. Each individual has its own distinct personality. The ability of wolves to form strong social bonds with one another is what makes the wolf pack possible. A dominance hierarchy is established within the pack,…

Selena: Early life and performing with Los Dinos: …1984, followed by the albums Alpha and Muñequito de Trapo (“Rag Doll”) two years later. In 1986, when Quintanilla was 15 years old, she won female entertainer of the year at the Tejano Music Awards, and her songs with Los Dinos began soaring on Latin music charts.

alanine: …one of which, L-alanine, or alpha-alanine (α-alanine), is a constituent of proteins. An especially rich source of L-alanine is silk fibroin, from which the amino acid was first isolated in 1879. Alanine is one of several so-called nonessential amino acids for birds and mammals; i.e., they can synthesize it from…

titanium processing: Alpha and beta phases: …into four classes: commercially pure, alpha, alpha-beta, and beta. Each class has distinctive characteristics. Pure titanium, although very ductile, has low strength and is therefore used when strength is not critical and corrosion resistance is desired. The alpha alloys are weldable and have good elevated-temperature strengths. The alpha-beta alloys are…

protein: The amino acid composition of proteins: …consist of long chains of α-amino (alpha amino) acids. The α-amino acids are so called because the α-carbon atom in the molecule carries an amino group (―NH2); the α-carbon atom also carries a carboxyl group (―COOH).

Alpha and Omega, in Christianity, the first and last letters of the Greek alphabet, used to designate the comprehensiveness of God, implying that God includes all that can be. In the New Testament Revelation to John, the term is used as the self-designation of God and of Christ. The reference in

Altair, the brighest star in the northern constellation Aquila and the 12th brightest star in the sky. With the bright stars Deneb and Vega, Altair (Arabic for “flying eagle”) forms the prominent asterism of the Summer Triangle. It is an A-type star 16.6 light-years from Earth. Altair rotates at

Capella, sixth brightest star in the night sky and the brightest in the constellation Auriga, with an apparent visual magnitude of 0.08. Capella is a spectroscopic binary comprising two G-type giant stars that orbit each other every 104 days. It lies 42.2 light-years from Earth. (List of Brightest

Arcturus, the fourth brightest star in the night sky, and the brightest star in the northern constellation Boötes, with an apparent visual magnitude of −0.05. It is an orange-coloured giant star 36.7 light-years from Earth. It lies in an almost direct line with the tail of Ursa Major (the Great

brass: Characteristics of the alloy: …former group, known as the alpha brasses, are widely used in the manufacture of pins, bolts, screws, and ammunition cartridge cases. The beta brasses are less ductile but stronger and thus are suitable for the manufacture of faucet handles, sprinkler heads, window and door fittings, and other fixtures. A third…

Sirius, brightest star in the night sky, with apparent visual magnitude −1.46. It is a binary star in the constellation Canis Major. The bright component of the binary is a blue-white star 25.4 times as luminous as the Sun. It has a radius 1.71 times that of the Sun and a surface temperature of

Procyon, brightest star in the northern constellation Canis Minor (Lesser Dog) and one of the brightest in the entire sky, with an apparent visual magnitude of 0.41. Procyon lies 11.4 light-years from Earth and is a visual binary, a bright yellow-white subgiant with a faint, white dwarf companion

Cor Caroli, binary star located 110 light-years from Earth in the constellation Canes Venatici and consisting of a brighter component (A) of visual magnitude 2.9 and a companion (B) of magnitude 5.5. It is the prototype for a group of unusual-spectrum variable stars that show strong and fluctuating

Canopus, second brightest star (after Sirius) in the night sky, with a visual magnitude of −0.74. Lying in the southern constellation Carina, 310 light-years from Earth, Canopus is sometimes used as a guide in the attitude control of spacecraft because of its angular distance from the Sun and the

islets of Langerhans: The alpha cells of the islets of Langerhans produce an opposing hormone, glucagon, which releases glucose from the liver and fatty acids from fat tissue. In turn, glucose and free fatty acids favor insulin release and inhibit glucagon release. The delta cells produce somatostatin, a strong…

Alpha Centauri, triple star system, the faintest component of which, Proxima Centauri, is the closest star to the Sun, about 4.2 light-years distant. The two brighter components, called A and B, about 0.2 light-year farther from the Sun, revolve around each other with a period of about 80 years,

Chamaeleon: Its brightest star is Alpha Chamaeleontis, with a magnitude of 4. This constellation was invented by Pieter Dircksz Keyser, a navigator who joined the first Dutch expedition to the East Indies in 1595 and who added 12 new constellations in the southern skies. It is named after the chameleon,…

Arctic Ocean: Topography of the ocean floor: …two unequal basins by the Alpha Cordillera (Alpha Ridge), a broad, rugged submarine mountain chain that extends to within 4,600 feet of the ocean surface. The origin of this seismically inactive ridge, which was discovered in the late 1950s, is undetermined and holds the key to understanding the origin of…

Alpha Crucis, brightest star in the southern constellation Crux (the Southern Cross) and the 13th brightest star in the sky. Alpha Crucis is about 320 light-years from Earth. It is a multiple star system consisting of three B-type stars, the spectroscopic binary α1 and α2, that are of roughly the

Deneb, one of the brightest stars, with an apparent magnitude of 1.25. This star, at about 1,500 light-years’ distance, is the most remote (and brightest intrinsically) of the 20 apparently brightest stars. It lies in the northern constellation Cygnus and, with Vega and Altair, forms the prominent

alpha decay, type of radioactive disintegration in which some unstable atomic nuclei dissipate excess energy by spontaneously ejecting an alpha particle. Because alpha particles have two positive charges and a mass of four units, their emission from nuclei produces daughter nuclei having a positive

Olivia Wilde: Acting career: House, Rush, and Babylon: …the horror mystery Turistas and Alpha Dog, a crime drama that featured Justin Timberlake. The following year she landed a recurring role on the TV series House, a medical drama centering on a brilliant but arrogant doctor played by Hugh Laurie; Wilde remained on the show until it ended in…

polestar: …is Polaris (α Ursae Minoris); Thuban (α Draconis) was closest to the North Pole about 2700 bce, and the bright star Vega (α Lyrae) will be the star closest to the pole in 14,000 ce. The location of the northern polestar has made it a convenient object for navigators to…

geomagnetic field: The geomagnetic dynamo: This process is called the alpha effect (because the effects are proportional with a constant, α, to the background field). Finally, small loops may merge into a single large loop, re-creating the initial poloidal field (D). In cells of sinking fluid the toroidal field wraps in the opposite direction and…

human nervous system: Muscle spindles: Called alpha (α) efferents, these fibers have either a static or a dynamic effect. The physiologically important point is that most of the motor supply to the muscle spindles is largely independent of that of the ordinary muscle fibers, and only a small part is obligatorily…

Achernar, brightest star in the constellation Eridanus and the ninth brightest star in the sky. Achernar (Arabic for “end of the river”) is 144 light-years from Earth. It is a binary star with a B-type star, Achernar A, as its primary and a much fainter A-type star, Achernar B, orbiting the primary

human nervous system: Muscle spindles: Called alpha (α) efferents, these fibers have either a static or a dynamic effect. The physiologically important point is that most of the motor supply to the muscle spindles is largely independent of that of the ordinary muscle fibers, and only a small part is obligatorily…

Castor, multiple star having six component stars, in the zodiacal constellation Gemini. The stars Castor and Pollux are named for the twins of Greek mythology. (List of Brightest Stars as Seen from Earth) Castor’s combined apparent visual magnitude is 1.58. It appears as a bright visual binary, of

haptoglobin: …a colourless protein of the α-globulin fraction of human serum (liquid portion of blood plasma after the clotting factor fibrinogen has been removed) that transports hemoglobin freed from destroyed red blood cells to the reticuloendothelial system, where it is broken down. Three common types—numbered 1-1, 2-1, and 2-2—and three uncommon…

bleeding and blood clotting: Platelets and their aggregation: …types of internal granules: the alpha granules, the dense granules, and the lysosomes. Each of these granules is rich in certain chemicals that have an important role in platelet function. For example, dense granules contain large quantities of calcium ions and adenosine diphosphate (ADP). Upon release from the platelet, ADP…

Ras Algethi, red supergiant star, whose diameter is nearly twice that of Earth’s orbit. It lies in the constellation Hercules and is of about third magnitude, its brightness varying by about a magnitude every 128 days. It is 380 light-years from Earth. The name comes from an Arabic phrase meaning

radioactivity: Alpha decay: …rate formula (6) is the hindrance factor. The existence of uranium-235 in nature rests on the fact that alpha decay to the ground and low excited states exhibits hindrance factors of over 1,000. Thus the uranium-235 half-life is lengthened to 7 × 108 years, a time barely long enough compared…

Horologium: Its brightest star is Alpha Horologii, with a magnitude of 3.9. The French astronomer Nicolas Louis de Lacaille formed this constellation in 1754; it represents a pendulum clock.

therapeutics: Biological response modifiers: Interferon-α is produced by a recombinant DNA process using genetically engineered Escherichia coli. Recombinant interferon-α appears to be most effective against hairy-cell leukemia and chronic myelogenous leukemia, lymphoma, multiple myeloma, AIDS-associated Kaposi sarcoma, and chronic hepatitis C

iron: Occurrence, uses, and properties: …is a transition to paramagnetic alpha iron, which is also body-centred cubic in structure. Below 773 °C (1,423 °F), alpha iron becomes ferromagnetic (i.e., capable of being permanently magnetized), indicating a change in electronic structure but no change in crystal structure. Above 773 °C (its Curie point), it loses its…

Regulus, brightest star in the zodiacal constellation Leo and one of the brightest in the entire sky, having an apparent visual magnitude of about 1.35. It is 77 light-years from Earth. The name Regulus, derived from a Latin word for king, reflects an ancient belief in the astrological importance

Lynx: Its brightest star is Alpha Lyncis, with a magnitude of 3.2. Polish astronomer Johannes Hevelius invented this constellation in 1687. Since all the stars in the constellation are quite faint, Hevelius wrote that its name came from one needing the eyesight of a lynx to see it.

Vega, brightest star in the northern constellation Lyra and fifth brightest in the night sky, with a visual magnitude of 0.03. It is also one of the Sun’s closer neighbours, at a distance of about 25 light-years. Vega’s spectral type is A (white) and its luminosity class V (main sequence). It will

Monoceros: Its brightest star is Alpha Monocerotis, with a magnitude of 3.9. This constellation contains R Monocerotis, a young star immersed in a nebula. In 1612 Dutch cartographer Petrus Plancius introduced this constellation on a celestial globe he made and represented it as a unicorn. Because this area of the…

human nervous system: Muscle spindles: Called alpha (α) efferents, these fibers have either a static or a dynamic effect. The physiologically important point is that most of the motor supply to the muscle spindles is largely independent of that of the ordinary muscle fibers, and only a small part is obligatorily…

Ophiuchus: Its brightest star is Rasalhague (from the Arabic for “the head of the serpent collector”), with a magnitude of 2.1. This constellation contains Barnard’s Star, the second nearest star to Earth at a distance of six light-years and the star with the largest proper motion. Kepler’s Nova, one of…

Betelgeuse, second brightest star in the constellation Orion, marking the eastern shoulder of the hunter. Its name is derived from the Arabic term bat al-jawzāʾ, which means “the giant’s shoulder.” Betelgeuse is one of the most luminous stars in the night sky. It is a variable star and usually has

human behaviour: Central nervous system processing: The dominant rhythm is the alpha wave, which reaches its maximum frequency in adolescence and begins to slow gradually after young adulthood. This slowing may be related to disease processes (particularly vascular disease) and to basic aging processes. The older adult’s central nervous system appears to be in a state…

alpha particle, positively charged particle, identical to the nucleus of the helium-4 atom, spontaneously emitted by some radioactive substances, consisting of two protons and two neutrons bound together, thus having a mass of four units and a positive charge of two. Discovered and named (1899) by

Pavo: Its brightest star is Alpha Pavonis, sometimes known as Peacock, with a magnitude of 1.9. This constellation was invented by Pieter Dircksz Keyser, a navigator who joined the first Dutch expedition to the East Indies in 1595 and who added 12 new constellations in the southern skies. Pavo represents…

astronomical map: Star names and designations: …article “the”: Aldebaran (“the Follower”), Algenib (“the Side”), Alhague (“the Serpent Bearer”), and Algol (“the Demon”). A conspicuous exception is Albireo in Cygnus, possibly a corruption of the words ab ireo in the first Latin edition of the Almagest in 1515. Most star names are in fact Arabic and are…

titanium processing: Alpha and beta phases: The atoms of pure titanium align in the solid state in either a hexagonal close-packed crystalline structure, called the alpha (α) phase, or a body-centred cubic structure, called the beta (β) phase. In the pure metal, transformation from the alpha to…

Phoenix: Its brightest star is Alpha Phoenicis, with a magnitude of 2.4. This constellation was invented by Pieter Dircksz Keyser, a navigator who joined the first Dutch expedition to the East Indies in 1595 and who added 12 new constellations in the southern skies. It represents the mythical phoenix, a…

Pictor: Its brightest star is Alpha Pictoris, with a magnitude of 3.3. The second brighest star, Beta Pictoris, is notable for an encircling disk of debris that might contain planets. The French astronomer Nicolas Louis de Lacaille formed this constellation in 1754. It represents a painter’s easel and was orginally…

Fomalhaut, the 18th star (excluding the Sun) in order of apparent brightness. It is used in navigation because of its conspicuous place in a sky region otherwise lacking in bright stars. It lies in the southern constellation Piscis Austrinus, 25 light-years from Earth. A white star, it has an

nervous system: Epinephrine and norepinephrine: …are divided into two types, α and β. These are further classified into subtypes α1, α2, β1, and β2.

Venus: Tesserae: …large elevated regions, such as Alpha Regio, are composed largely of tessera terrain. Such terrain appears extraordinarily rugged and highly deformed in radar images, and in some instances it displays several different trends of parallel ridges and troughs that cut across one another at a wide range of angles. The…

Reticulum: Its brightest star is Alpha Reticuli, with a magnitude of 3.3. The French astronomer Nicolas Louis de Lacaille formed this constellation in 1754. It represents the reticle, a device consisting of a network of silk threads placed in a telescope’s eyepiece and used to measure positions of celestial objects.…

human behaviour: Central nervous system processing: The dominant rhythm is the alpha wave, which reaches its maximum frequency in adolescence and begins to slow gradually after young adulthood. This slowing may be related to disease processes (particularly vascular disease) and to basic aging processes. The older adult’s central nervous system appears to be in a state…

Antares, red, semiregular variable star, with apparent visual magnitude about 1.1, the brightest star in the zodiacal constellation Scorpius and one of the largest known stars, having several hundred times the diameter of the Sun and 10,000 times the Sun’s luminosity. It has a fifth-magnitude blue

Ida B. Wells-Barnett: …Black women’s suffrage group, Chicago’s Alpha Suffrage Club. From 1913 to 1916 she served as a probation officer of the Chicago municipal court. She was militant in her demand for justice for African Americans and in her insistence that it was to be won by their own efforts.

dementia with Lewy bodies: …of a protein known as alpha-synuclein—in the brain. Lewy bodies are named for German physician Friedrich Heinrich Lewy, who first described them (1912), in the context of Parkinson disease.

Aldebaran, reddish giant star in the constellation Taurus. Aldebaran is one of the 15 brightest stars, with an apparent visual magnitude of 0.85. Its diameter is 44 times that of the Sun. It is accompanied by a very faint (13th magnitude) red companion star. Aldebaran lies 65 light-years from

Polaris, Earth’s present northern polestar, or North Star, at the end of the “handle” of the so-called Little Dipper in the constellation Ursa Minor. Polaris will be closest to the north celestial pole in about 2100, and, because of the precession of Earth’s axis, in several centuries Polaris will

Spica, brightest star in the zodiacal constellation Virgo and one of the 15 brightest in the entire sky, having an apparent visual magnitude of 1.04. It is a bluish star; spectroscopic examination reveals Spica to be a binary with a four-day period, its two components being of the first and third

human behaviour: Central nervous system processing: The dominant rhythm is the alpha wave, which reaches its maximum frequency in adolescence and begins to slow gradually after young adulthood. This slowing may be related to disease processes (particularly vascular disease) and to basic aging processes. The older adult’s central nervous system appears to be in a state…

emphysema: …is an inherited deficiency of alpha-1 antitrypsin, an enzyme that normally protects the lungs from injury caused by cigarette smoke. Smokers who inherit an abnormal gene for alpha-1 antitrypsin from both parents often develop progressive, severe emphysema, especially in the lower lungs, beginning before the age of 40. Nonsmokers who…

nervous system: Epinephrine and norepinephrine: …are divided into two types, α and β. These are further classified into subtypes α1, α2, β1, and β2.

amylase: Alpha-amylase is widespread among living organisms. In the digestive systems of humans and many other mammals, an alpha-amylase called ptyalin is produced by the salivary glands, whereas pancreatic amylase is secreted by the pancreas into the small intestine. The optimum pH

titanium processing: Alpha and beta phases: …four classes: commercially pure, alpha, alpha-beta, and beta. Each class has distinctive characteristics. Pure titanium, although very ductile, has low strength and is therefore used when strength is not critical and corrosion resistance is desired. The alpha alloys are weldable and have good elevated-temperature strengths. The alpha-beta alloys are widely…

immune system: Structure of the T-cell receptor: …type of receptor is called alpha-beta because it is composed of two different chains, one called alpha and the other beta. A less common type is the gamma-delta receptor, which contains a different set of chains, one gamma and one delta. A typical T cell may have as many as…

tear gas: …tear gases are ω-chloroacetophenone, or CN, and o-chlorobenzylidenemalononitrile, or CS. CN is the principal component of the aerosol agent Mace and is widely used in riot control. It affects chiefly the eyes. CS is a stronger irritant that causes burning sensations in the respiratory tract and involuntary closing of the…

cristobalite: Cristobalite has two modifications: low-cristobalite, which occurs naturally up to 268° C (514° F) but is not stable; and high-cristobalite, which occurs above 268° C but is only stable above 1,470° C. Natural low-cristobalite usually occurs in sub-microcrystalline masses (see opal) or fibrous to columnar spherulites (see lussatite) in…

cancer: Molecular evaluation: …pancreatic or gastrointestinal cancers; and alpha-fetoprotein and chorionic gonadotropin, which can indicate testicular cancer. The diagnostic tests that are necessary to identify genetic alterations and tumor markers and thereby predict the efficacy of a drug are sometimes referred to as companion diagnostics.

lone star tick: Alpha-gal syndrome: Lone star ticks have alpha-gal, a sugar molecule also found in the tissues of all non-primate mammals, in their saliva. When alpha-gal is passed to a human through the tick’s saliva, the person’s immune system sometimes responds by producing antibodies against it. Now sensitized to alpha-gal, the affected person…

lone star tick: Alpha-gal syndrome: …in the United States is alpha-gal syndrome (other ticks can cause the syndrome elsewhere in the world). Lone star ticks have alpha-gal, a sugar molecule also found in the tissues of all non-primate mammals, in their saliva. When alpha-gal is passed to a human through the tick’s saliva, the person’s…

lone star tick: Alpha-gal syndrome: …in the United States is alpha-gal syndrome (other ticks can cause the syndrome elsewhere in the world). Lone star ticks have alpha-gal, a sugar molecule also found in the tissues of all non-primate mammals, in their saliva. When alpha-gal is passed to a human through the tick’s saliva, the person’s…

helium dating: …the method is called the alpha-helium radioactive clock. Alpha particles are the nuclei of helium atoms emitted from the nucleus of the radioactive progenitor.

lactic acid, an organic compound belonging to the family of carboxylic acids, present in certain plant juices, in the blood and muscles of animals, and in the soil. It is the commonest acidic constituent of fermented milk products such as sour milk, cheese, and buttermilk. First isolated in 1780 by

fatty acid: Essential fatty acids: … (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid). Those fatty acids are required, however, for cellular processes and the production of other necessary omega-3 and omega-6 fatty acids. Thus, because they must be taken in through the diet, they are called essential fatty acids. Omega-6 and omega-3…

metabolism: Incomplete oxidation: …oxaloacetate; and the five-carbon compound α-oxoglutarate. The first, acetate in the form of acetyl coenzyme A, constitutes by far the most common product—it is the product of two-thirds of the carbon incorporated into carbohydrates and glycerol; all of the carbon in most fatty acids; and approximately half of the carbon…

radiation: Neutrons: …particles provides the basis for alpha-particle welding. The principle of such welding, invented by the Soviet chemist V.I. Goldansky, is to deposit a thin layer of a boron (or lithium) compound in the interface between diverse materials, which is thereafter irradiated with neutrons. The high-energy α-particles produced from the nuclear…

silica mineral: High quartz (β-quartz): …transition to ordinary quartz (low quartz) on cooling, and all ordinary quartz, when heated above the transition temperature, is transformed into high quartz. The transformation involves displacement of the linkage between the tetrahedrons; no bonds are broken.

thalassemia: Genetic defects of thalassemia: …the most severe form (homozygous α-thalassemia) usually causes premature birth, either stillborn or with death following within a few hours. It is thought that a primary thalassemia genetic mutation results in reduction in the rate at which α-, β-, or δ-chains are manufactured, the chains being otherwise normal. The relative…