gamman.adj.
/ˈɡamə/, U.S. /ˈɡæmə/ A. n.
I. The letter.† 2. Music. = gamut n. (in various senses). Obsolete.† 5. Surgery. A gamma-shaped cauterizing instrument used in the treatment of hydrocele. Cf. quot. 1846 at Compounds 1a. Obsolete. historical. rare.Apparently only attested in dictionaries or glossaries.
1. (The name of) the third letter (Γ, γ) of the Greek alphabet.In transliterating ancient Greek, usually rendered as g.
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society > communication > writing > written character > name of written character > [noun] > Greek
alphac1175
muc1175
betaa1400
taua1400
chic1400
deltac1400
etac1400
kappac1400
gamma?a1425
lambda?a1425
nu?a1425
phi?a1425
pi?a1425
psi?a1425
rho?a1425
xi?a1425
zeta?a1425
upsilon1559
san1584
omega1599
theta1603
iota1607
sigma1607
omicron1631
digamma1699
epsilon1842
zeta1850
?a1425 Mandeville's Trav. (Egerton) (1889) 11 Here ȝe may see þam [sc. the Greek letters] and þer names also: alpha..beta..gamma [etc.].
1573 T. Twyne tr. H. Llwyd Breuiary of Britayne f. 75v As in all other, yt C, and G, haue the force of Cappa, & Gamma.
1651 J. F. tr. H. C. Agrippa Three Bks. Occult Philos. ii. xiv. 27 Thou shalt bend thy thumb with the outward joynt, like to the Greek Gamma, to the Palme.
1746 T. Nugent tr. C. Lancelot et al. New Method of learning Greek Tongue I. i. i. 3 The Greeks have 24 letters..alpha..beta..gamma..phi..chi..[etc.].
1756 P. Pott Treat. Ruptures xi. 178 Cauteries of very different shapes have been proposed, triangular, elliptical, circular, and in the form of the Greek letter gamma.
1823 Eclectic Rev. Dec. 491 He proceeds to form a hieroglyphic alphabet comprising eleven forms of Alpha, five of Beta, two Gammas, two Deltas, [etc.].
1871 Med. Times & Gaz. 25 Nov. 668/2 This is a Greek word—αγγελος—spelt with two gammas.
1900 Methodist Rev. May 399 This letter..was called digamma because it looked like two gammas, one superposed upon the other.
1961 Hesperia 30 20 In line 19 the first gamma is certain, both from the visible horizontal stroke..and from the spacing.
2000 R. S. Kraemer & S. L. Lander in P. F. Esler Early Christian World II. xli. 1058 According to one family of Latin manuscripts (identified by the Greek letter gamma) and the only extant Greek manuscript, she came from [etc.].
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society > leisure > the arts > music > musical sound > pitch > system of sounds or intervals > [noun] > great scale or gamut > notes in gamut
gammea1393
gamuta1450
quatreblea1450
superacute1504
ela1580
gamma1602
sur-sharp1786
1602 S. Patrick tr. J. de Hainault Estate of Church 284 At this time flourished in Italie, Guido Aretin, a Monke of the order of S. Benet, an excellent Musitian, who first inuented the Gamma [Fr. la game] to learne vpon the hand.
1622 H. Peacham Compl. Gentleman xi. 104 Two Lutes of equall size being..tuned Vnison, or alike in the Gamma, G sol re vt, or any other string.
1724 Short Explic. Foreign Words Musick Bks. Gama or Gamma, is what we call the Gamut.
1730 N. Bailey et al. Dictionarium Britannicum Gam, Gama, Gammot, the first or gravest Note in the modern Scale of Musick.
1825 J. F. Danneley Encycl. Music Gamme..Gamma, Gamut or Gammut.
3. Astronomy. Used in the name of the third star (typically the third brightest) of a constellation. Usually with the genitive of the Latin name of the constellation (or an abbreviation of this) as a postmodifier. Usually written γ.The use of Greek letters to designate the stars in a constellation was introduced by J. Bayer in Uranometria (1603).
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1717 Philos. Trans. 1714–16 (Royal Soc.) 29 432 It very much resembled the Tail of a Comet, and was about 20 gr. inclined from the Perpendicular to the Right, beginning about γ of Bayer on the Corona Borea.
1744 Philos. Trans. (Royal Soc.) 43 91 It [sc. the comet] formed, at that time, an obtuse-angled Triangle, with (α) of Andromeda, and (γ) Pegasi, the Comet being at the obtuse Angle.
1834 Philos. Trans. (Royal Soc.) 124 209 The erection of a zenith telescope..for the purpose of measuring the zenith distance of γ Draconis.
1899 R. H. Allen Star-names 50 Aquarius is not conspicuous, being marked chiefly by the stars γ, ζ, η, and π.
1910 G. P. Serviss Round Year with Stars iii. 79 None of its stars exceeds the fourth magnitude; but three of them, Alpha, Beta, and Gamma, are telescopic doubles.
1989 J. B. Kaler Stars & their Spectra x. 203 ζ Pup and γ Vel, lie within an extraordinary volume of space outlined by..the vast remnant of an exploded star.
2006 Daily Tel. 1 Jan. 22/7 In neighbouring Sextans, the two brightest stars, Alpha and Gamma, are so obscure that they do not even have popular names, which seems unfair in view of their brightness!
4. In full gamma moth. The silver Y moth, Autographa gamma, a Holarctic noctuid moth having brownish forewings with a silvery mark in the shape of the letter Y or the Greek letter γ; also called silver gamma.
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the world > animals > invertebrates > phylum Arthropoda > class Insecta > Heterocera > [noun] > family Plusiidae > member of genus Plusia > plusia gamma (gamma moth)
gamma1799
silver y1832
1799 E. Donovan Nat. Hist. Brit. Insects VIII. 34 Phalæna Gamma. Common γ Moth.
1821 Time's Telescope: Guide to Almanack 257 The gamma moth..haunts our clover fields when in bloom.
1879 Times 25 Aug. 10/5 The gamma is one of the few day-flying moths, and on the occasion of which I speak it would have been difficult to have found a flower of any description without a tenant.
1903 Garden 12 Sept. 179/2 The Michaelmas Daisies are also much appreciated, but more especially by moths, the silver gamma often haunting the plants in hundreds.
1961 B. Meeuse Story Pollination xvii.190 A moth that everyone in this country should know..is the little gamma moth.
2005 Jrnl. Chem. Ecol. 31 2153 We found the gamma moth to be sexually active throughout the scotophase.
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the world > health and disease > healing > medical appliances or equipment > other surgical equipment > [noun] > cautery
cultellary?a1425
olivary?a1425
cultelere?c1425
branding-ironc1440
burning-iron1483
cautera1533
actual?1541
cautelayre?1541
searing-iron1541
cautery1543
actual cautery1575
cauterizing iron1575
olive cautery1598
back-cauter1611
cauting-iron1688
brand1692
gamma1809
thermo-cautery1879
1809 B. Parr London Med. Dict. I. 696/2 Gamma,..an instrument mentioned by P. Ægineta,..used for cauterising a hernia aquosa.
1848 J. Craig New Universal Dict. Gamma..a surgical instrument used for cauterising a hernia—so called from its shape resembling that letter.
6. A third-class mark awarded in an examination, test, etc.; a paper, candidate, etc., meriting such a mark. Sometimes with a following modifying word or phrase, indicating relative position within the (notional) third class, as gamma minus, gamma plus, etc.
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society > education > educational administration > examination > [noun] > marks > specific marks
accessit1753
honour1774
credit1802
second class1810
firsta1830
first class1830
third class1844
Hons.1850
max1851
second1852
special mention1886
distinction?1890
A1892
E1892
pass mark1894
two-two1895
alpha1898
alpha plus1898
gamma1898
beta1902
delta1911
alpha minus1914
fourth1914
straight A1926
two-one1937
lower second1960
honourable mention2011
1898 M. Beerbohm in Sat. Rev. 28 May 710/1 The examiners..marked my paper ‘gamma-minus-query’.
1914 M. West Educ. & Psychol. ii. 21 Even if the boy passes, the classes are given on the average of the papers; gammas (‘bads’) cancel out alphas (‘goods’), whereas in life an alpha is an alpha.
1956 L. E. Jones Edwardian Youth iv. 98 A Second Class in Greats, thanks to ‘Gammas’ for Greek and Latin composition.
1973 Mod. Lang. Rev. Oct. 837 I cannot resist the temptation to bestow..Gamma-minus..on [the poet] Firdusi; Gamma-plus on the maker of ‘Il'ya and Sokol'nik’; [etc.].
2010 Guardian (Nexis) 20 Apr. 10 Her essay received a double gamma minus, taking her total result from a first to a third.
7. Physics. A gamma particle or ray; (as a mass noun) gamma radiation. Esp. in attributive and objective compounds, as gamma counter, gamma emitter, gamma-emitting adj., gamma irradiation, etc. Frequently written γ.See also gamma camera n. at Compounds 1c, gamma knife n. at Compounds 1c.
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1919 Hahnemannian Monthly Mar. 191 The reason he commences with massive gamma irradiation is that too small a dosage stimulates cell proliferation.
1930 Nature 20 Dec. 953/2 Either a γ-quantum is emitted or one of the extra-nuclear electrons [is] thrown out of the atom.
1949 W. S. Eastwood Surv. Pile Made Isotopes 1 Sources of this kind have previously been confined to the natural gamma emitting elements.
1955 Jrnl. Amer. Chem. Soc. 77 802/1 It would not be detected by the γ-counters which were used for Ra-analysis.
1965 Bull. Amer. Metereol. Soc. 46 555 Here gammas from a source in one tube pulse through the snowpack to the other tube.
1971 Nature 12 Mar. 120/2 Corneas were first irradiated for 15 h in a γ-irradiator..delivering 1·2 × 105 rad/h.
2005 L. K. Massey Effect Sterilization Methods Plastics (ed. 2) 2/2 Plastic parts sterilized by electron beam are only exposed for minutes versus hours or days with gamma.
8. After Aldous Huxley's use (see quot. 19321): a person considered as belonging to a caste or class characterized by third-rate intelligence. Cf. A. 6.
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1932 A. Huxley Brave New World i. 4 The fertilized ova went back to the incubators; where the Alphas and Betas remained until definitely bottled; while the Gammas, Deltas and Epsilons were brought out again, after only thirty-six hours.
1932 A. Huxley Brave New World xi. 188 The fifty-six..machines were being manipulated by fifty-six aquiline and ginger Gammas.
1974 K. Millett Flying (1975) ii. 170 A type of drudge, some gamma out of Huxley's Brave New World.
2000 S. White in C. McKinnon & I. Hampsher-Monk Demands of Citizenship iv. 81 Casting a wary eye back to the dystopias depicted by Wells and Huxley, we can picture a society in which highly taxed ‘alphas’ peer down with contempt at modestly taxed ‘betas’, who in turn peer down with contempt at heavily subsidized ‘gammas’.
II. As a symbol or name for various quantities or units in science. Frequently written γ.
9. Originally (Photography): the gradient of the straight-line portion of the characteristic curve of a photographic emulsion, taken as measuring the contrast (contrast n. 2b) of the developed image compared with that of the scene photographed; (also) the contrast itself. In later use also: a measure of the relationship between the input and output luminance values of a video image, which can be adjusted to improve the perceived contrast of the image.
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society > leisure > the arts > visual arts > photography > a photograph > qualities and effects > [noun] > contrast, etc.
high contrast1895
gamma1903
contrast1911
step wedge1931
society > communication > broadcasting > television > visual element > [noun] > television picture or image > tone differentiation > measure of
gamma1937
1903 Photogr. Jrnl. 43 48 The relation between the development factor (afterwards called γ) and the time of development (t).
1912 B. E. Jones Cassell's Cycl. Photogr. I. 109/2 Watkins has done away with the sector wheel..and the finding of the gammas.
1937 A. T. Witts Television Cycl. 65 The contrast in detail in a picture, sometimes referred to as the gamma of the picture.
1961 G. Millerson Technique Television Production iii. 48 From the angle of the slope, the curve's gamma can be deduced (tan α).
1962 Unesco Bull. Libr. 16 16 A high value of gamma is desirable in photographic reproduction of lines, as in the pages of a printed book.
2003 3D World June 61/1 In the new comp, add a Levels Filter to correct its gamma.
10. Geology and Physics. A unit of magnetic field strength, equal to 10−5 oersted (approx. 7.96 × 10−4 ampere per metre).
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1903 Nature 5 Nov. 6/1 There was a movement of the declination needle to the west through about 34′, and a diminution of 240 γ in the horizontal force.
1931 F. H. Lahee Field Geol. (ed. 3) xxiii. 674 Isanomalies..express in gammas the local variations from the average total magnetic intensities in the area.
1967 New Scientist 7 Dec. 617/2 The lunar magnetic field is no bigger than two gammas.
2010 S. Soloman Sensors Handbk. xvi. 455 Another unit that is sometimes used for very small magnetic fields is the gamma.
11. A unit of mass or weight, equal to one millionth of a gram; = microgram n. Now historical.
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the world > relative properties > measurement > measurement by weighing > [noun] > unit or denomination of weight > metric gram(me) > decimal parts of
centigram1795
milligram1797
decigram1801
mg1892
mgm1909
gamma1931
1931 Industr. & Engin. Chem. (Analyt. ed.) 15 July 314/2 The value obtained was 4·0 γ copper per gram (1 γ = 0·001 mg.) for the combined filtrates.
1937 C. D. Miller et al. Some Fruits of Hawaii (ed. 2) 108 1 unit is equivalent to 0.6 gamma of carotene.
1940 Industr. & Engin. Chem. 15 June 359/2 For 0·001 milligram the term ‘micro~gram’, designated by the symbol γ (the word ‘gamma’ should not be used as a substitute for ‘microgram’).
1956 A. Huxley Let. 23 Sept. (1969) 807 Fifty gamma of LSD were sufficient to produce in me virtually the full effect of the standard dose.
2006 S. Grof When Impossible Happens p. xxx In this planned self-experiment, he [sc. Huxley] ingested 250 micrograms or gammas (millionths of a gram) of LSD.
B. adj. (Usually attributive). Chiefly in scientific and technical contexts: that is the third in a series of three or more related things designated with Greek letters.
1. Chemistry. Designating the third of three or more structurally similar or chemically related (spec. isomerous) compounds. Also: designating the third carbon atom in order of position relative to the main functional group of an organic compound, and compounds having a specific functional group attached to this carbon. Cf. alpha adj. 1, beta n. 2b.See also Compounds 2b.
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1834 J. D. Morries in G. Graves Hortus Medicus 151 The alcohol at the same times takes up another resin, which Berzelius designates ‘Resin gamma’.
1862 J. C. Booth & C. Morfit Encycl. Chem. (ed. 2) 305/1 The gamma-resin leaving the other two, of which alpha-resin is soluble in ether.
1904 Jrnl. Chem. Soc. 85 ii. 1052 If..the lactones of aldonic acids are γ-lactones, then tetramethyl gluconolactone is a γ-lactone.
1945 Pop. Mech. Mag. Sept. 10/3 Called Gammexane or 666, the super-DDT is chemically the gamma isomer of benzene hexachloride, and is not particularly close to DDT in structural chemistry.
1964 A. J. Ihde Develop. Mod. Chem. xiii. 349 Lactone formation is to be expected when a hydroxyl group occurs on a carbon atom gamma to a carboxyl group.
1997 Lett. Appl. Microbiol. 25 113 Most industrial processes use the bioconversion of ricinoleic acid by yeasts to produce γ-decalactone.
2006 New Yorker 18 Dec. 44/1 Gamma interferon has since proved effective in treating children with a rare immune-system disorder called chronic granulomatous disease.
2. Metallurgy.
a. Designating the third in a series of allotropes. Cf. alpha adj. 2a, beta n. 2g(a). gamma iron n. the allotrope of iron stable between 910°C and 1,403°C, characterized by a face-centred cubic crystal structure.
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1848 D. P. Gardner Med. Chem. 130 The difference of properties can only be attributed to the presence of the elements in different allotropic states... A new nomenclature, with appropriate symbols, has, therefore, been recommended. The active phase has been designated the alpha (α) state, and, other phases, beta (β), gamma (γ), &c.
1868 J. D. Dana Syst. Mineral. (ed. 5) Introd. p. xv These different states of elements are best designated in the symbol by the letters of the Greek alphabet, as thus the confusion arising from the conflicting numbers for atomic weights and combining relations are avoided..αRO 3 βRO 2 γRO [etc.].
1896 F. Osmond in Jrnl. Iron & Steel Inst. 49 180 It was necessary to distinguish at least three molecular states of iron, which were respectively stable within certain limits of temperature: α below 700°, β between a range of 750° to 860°, γ above 860°.
1911 L. T. O'Shea Elem. Chem. Coal-mining Students vi. 99 The chief of these modifications are (1) rhombic or alpha sulphur, (2) prismatic or beta sulphur, (3) plastic or gamma sulphur.
1973 Gramophone Jan. 1404/2 For recording tape manufacture a gamma iron oxide with crystalline structure is employed.
2003 L. E. Samuels Metallogr. Polishing by Mech. Methods (ed. 4) iii. 37/2 An allotrope of Al2O3 that has a hexagonal crystal structure (gamma alumina) is also manufactured.
b. Designating an alloy having the percentage of a particular metal in a certain range, as gamma brass, gamma bronze; cf. alpha adj. 2b, beta n. 2g(b). Also (in extended use): designating a phase of an alloy having a crystal structure analogous to that of gamma brass.
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society > occupation and work > materials > derived or manufactured material > metal > alloy > [adjective] > types or qualities of alloys
gamma1904
substitutional1923
solution-treated1952
maraged1961
solutionized1978
1904 E. S. Shepherd in Jrnl. Physical Chem. 8 435 Copper and zinc unite to form six series of solid solutions, which have been distinguished [in this paper] as α, β, γ, δ, ε, and η.
1925 London, Edinb. & Dublin Philos. Mag. 6th Ser. 50 311 Some authors have supposed γ-brass to be CuZn2, while others believe that it is a solid solution of zinc in Cu2Zn3.
1949 C. L. Martell Tin (ed. 2) xi. 239 Under this curve we find an area in which gamma-bronze is in stable equilibrium with the liquid alloy.
1973 Jrnl. Less Common Metals 30 366 An analogous phase was found, isotypic with ‘Ce5Hg21’, the structure of which..is ascribed to the gamma-brass family.
2010 U. Mizutani Hume-Rothery Rules for Structurally Complex Alloy Phases i. 3 The γ-phase is often referred to as the gamma-brass phase and will be treated..as the representative of structurally complex alloy (CMA) phases.
3. Physiology. Designating a pattern of electrical activity in the brain characterized by high-frequency waves (35 to 100 cycles per second), thought to be associated with functions such as information processing, cognition, and consciousness. Esp. in gamma rhythm, gamma wave. Cf. alpha adj. 3a, beta n. 2h.
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1938 H. H. Jasper & H. L. Andrews in Arch. Neurol. & Psychiatry 39 103 These higher frequencies (from 35 to 45 per second, which might be called gamma waves) have not as yet been observed with sufficient regularity for analysis.
1977 Jrnl. Res. Music Educ. 25 162 Further research is recommended designed specifically to learn more about the properties of gamma waves.
2002 R. Carter Consciousness iv. 124 The idea that gamma waves underlie consciousness has been heavily championed by Francis Crick.
2008 New Yorker 28 July 43/ The gamma rhythm is thought to come from the ‘binding’ of neurons, as cells distributed across the cortex draw themselves together into a new network, which is then able to enter consciousness.
4. British. Stock Market. Designating stocks and shares in the third category (those least intensively traded) in a system that classifies stocks available through the Stock Exchange Automated Quotation system (SEAQ). Now disused.The categorization of shares as alpha, beta, and gamma, according to how actively they were traded, was discontinued in 1991.
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society > trade and finance > stocks and shares > stocks, shares, or bonds > [adjective] > types of securities
unissued1703
preferable1837
ordinary1866
pre-preference1867
gilt-edge1880
gilt-edged1881
unlisted1882
voting1883
assented1907
voteless1908
senior1914
well-traded1936
medium-dated1943
off-board1943
go-go1966
unquoted1969
alpha1984
gamma1986
1986 Financial Times 12 Apr. (Weekend FT section) p. v/4 SAEF could be extended in various way[s] so as to cover smaller Gamma stocks.
1986 Observer 14 Sept. 34/8 Investment clients are as concerned about the future of gamma securities as corporate clients.
1991 Economist 6 July 87/3 The bulk of trading in beta and gamma shares in London takes place by brokers matching bids and offers, not through market quotes.
2003 J. White Investing Stocks & Shares (ed. 6) ii. 42 Prior to 1991..Gamma stocks formed the bulk of the market.
Compounds
C1. Compounds of the noun.
a. Similative, as gamma-shaped adj.
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1846 F. Adams tr. Paulus Ægineta Seven Bks. II. vi. 367 Having heated ten or twelve cauteries, shaped like the Greek letter Γ [Gk. δέκα ἢ δώδεκα τῶν γαμμοειδῶν καυτήρων], and two sword-shaped ones, we must first burn the scrotum through the middle with the gamma-shaped [cauteries].
1893 W. M. Ramsay Church in Rom. Empire xii. 262 A gamma-shaped crypt, attached to a small chapel.
1965 Jrnl. Kansas Entomol. Soc. 38 11 It is a gamma-shaped, flat plate lying in the horizontal plane of the sternum.
2006 Archaeol. Rep. for 2005–6 (Soc. for Promotion Hellenic Stud.) No. 52. 77/2 It comprises five rooms and one gamma-shaped courtyard.
b. Mathematics.
gamma distribution n. a continuous statistical distribution of two parameters α and β of which the chi-squared and exponential distributions are special cases, given by f(x) = βαxα−1e−βx/ Γ(α), for x, α, β all positive, where Γ is the gamma function.
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1937 Ann. Math. Statistics 8 152 It will often be sufficient to use the normal distribution to which the gamma distribution tends as N becomes large.
1973 Jrnl. Amer. Statist. Assoc. 68 928/1 We derive a test of whether the dependent variable follows a lognormal or a Gamma distribution.
2011 D. S. Wilks Statist. Methods in Atmospheric Sci. (ed. 3) iv. 97 The versatility in shape of the gamma distribution makes it an attractive candidate for representing precipitation data.
gamma function n. a function (symbol Γ) which extends the notion of factorial n (written n!) from positive whole numbers to real and complex variables, given by Γ(z) = ∫∞0tz − 1e−tdt.The function has the properties that Γ(z) = (z − 1)!, and Γ(z + 1) = zΓ(z), and is undefined for values of z that are negative whole numbers or zero. The incomplete gamma function is obtained by varying one or other of the limits of integration in the defining equation.The function was devised by Euler in 1729 ( L. Euler Let. 13 Oct. 1729 , in P. H. Fuss Correspondance mathématique et physique (1843) I. 3–4), but not named by him; the name and symbol Γ were given by Legendre in 1809 ( Mém. de la classe des sci. mathématiques et physiques de l'Inst. de France, année 1809 (1810) 477; also A. M. Legendre Exercises de calcul intégral (1811) I. ii. 277).
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the world > relative properties > number > calculus > [noun] > integral calculus > integration or integrability > integral
fluent1706
integral1728
gamma function1834
surface integral1867
Riemann integral1894
Cauchy's integral1898
Lebesgue integral1905
Stieltjes integral1914
convolution1934
1834 Rep. Brit. Assoc. Advancem. Sci. 1833 222 (note) Legendre has named the function Γ (1 + r) = 1. 2... r, the function gamma.
1843 Penny Cycl. XXV. 120/2 One of the first of these [transcendental quantities] will be the well-known function of n, which is generally designated by Γn, and is sometimes called the gamma-function, sometimes the factorial function.
1875 B. Williamson Elem. Treat. Integral Calculus (rev. ed.) 150 All definite integrals which are reducible to Gamma-functions.
1908 T. J. I'A. Bromwich Introd. Theory Infinite Series 461 (heading) Stirling's asymptotic formula for the gamma-function when x is real, large and positive.
1922 Jrnl. Inst. Actuaries 53 309 The incomplete Γ-function..is not convenient, as it stands, either for tabulation or for computation.
1998 A. A. Vigasin in A. A. Vigasin & Z. Slanina Molecular Complexes in Earth's Planetary, Cometary & Interstellar Atmospheres i. 18 Integration over E yields an incomplete gamma-function.
2005 Brit. Jrnl. Hist. Sci. 38 200 He devoted much of his energy to exploring gamma functions, integral equations and the behaviour of asymptotic expansions.
c. In sense A. 7.
gamma camera n. a device used to produce an image of a source of gamma rays, typically by detecting scintillation; esp. one used in medical scintigraphy.
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1953 Engin. Jrnl. (Montreal) July 840/2 The gamma camera competes with X-ray for cheaper, faster welding inspection.
1974 R. M. Kirk et al. Surgery iv. 62 The radioactivity can be detected with a gamma camera, often before radiographic changes take place.
1986 Dumfries & Galloway Standard 25 Apr. 4/6 We have recently paid £250,000 for a gamma camera to locate tumours.
2002 Wall St. Jrnl. 9 Apr. d12/4 Because the Apomate protein also bears a radioactive molecule, hospital gamma cameras can record the extent of cell death in a tumor after a single dose of chemotherapy.
gamma knife n. Surgery a device that focuses beams of gamma rays on a precise point within the brain or other part of the body in order to destroy abnormal tissue.
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1970 New Scientist 3 Dec. 377/1 Surgery in the depth of the brain with a ‘gamma knife’ to produce lesions can now be considered a practical technique.
1990 Neurosurg. Clin. N. Amer. 1 991 By measuring beam energy, beam accuracy, and dose gradient, it is possible to compare them to the older radiosurgical device, the gamma knife.
2003 S. Greenfield Tomorrow's People (2004) vi. 158 A greater finesse in brain location can be achieved with a ‘Gamma Knife’—a device that uses ionizing radiation to allow neurosurgeons to operate on abnormal areas of the brain without making an incision.
C2. Compounds of the adjective.
a. Physics.
gamma particle n. a photon of gamma radiation.
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1926 R. W. Lawson tr. G. von Hevesy & F. A. Paneth Man. Radioactivity iv. 49 A γ-‘particle’ produces 1·5 pairs of ions per unit of length.
1974 Billboard 11 May 45/1 Audio Magnetics has greatly improved upon their cobalt-doped coatings, conducting research on gamma particles.
2003 M. E. Byrnes et al. Nucl., Chem., & Biol. Terrorism (2005) ii. 38 Alpha-emitting radionuclides may also emit gamma particles.
gamma radiation n. one of the three main forms of radiation emitted by radioactive material, consisting of electromagnetic waves of very short wavelength.Originally regarded as the third and most penetrating kind of radiation emitted by radium, and later shown to be identical with very short wavelength (very energetic) X-rays. Gamma radiation is now usually defined in terms of the mode of production: gamma rays are produced by the radioactive decay of atomic nuclei, while X-rays are produced by the deceleration of charged particles, esp. electrons, or by electron transitions in atoms.
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the world > matter > physics > atomic nucleus > radioactivity > gamma radiation > [noun]
gamma radiation1904
1904 R. J. Strutt Becquerel Rays iii. 83 I have succeeded in observing the γ-radiation from 10 milligrammes of radium bromide.
1958 Listener 30 Oct. 704/1 Food-preservation by gamma radiation.
2008 I. M. Banks Matter iv. 67 Intense bursts of gamma radiation emanating from the floor/ceiling structure itself flooded either individual levels or the whole world.
gamma ray n. a photon of gamma radiation; (also) (attributive or in plural) gamma radiation.
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the world > matter > physics > atomic nucleus > radioactivity > gamma radiation > [noun] > ray of
gamma ray1903
1903 E. Rutherford in London, Edinb. & Dublin Philos. Mag. 6th Ser. Feb. 177 The γ rays, which are non-deviable by a magnetic field, and which are of a very penetrating character.
1904 Daily Chron. 6 June 4/4 It is probably the ‘gamma’ rays from radium, similar to Röntgen rays.
1961 G. R. Choppin Exper. Nucl. Chem. iii. 30 Frequently, rather than emit a gamma ray, a nucleus will..cause emission of an electron.
1969 Times 29 Sept. 12/6 What is almost certainly the discovery of the first gamma ray star has now been reported.
2010 N.Y. Mag. 9 Aug. 72/1 Nothing, by the way, explains his sudden surge of superheroism: no gamma rays or mutant spider bites.
b.
gamma-aminobutyric acid n. Biochemistry and Physiology an amino acid found principally in the central nervous system of vertebrates, where it acts as an inhibitory neurotransmitter; abbreviated GABA.Systematic name: 4-aminobutanoic acid; H2N(CH2)3COOH.
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1890 Jrnl. Chem. Soc. 58 i. 360 When digested for three hours with 27 per cent. hydrochloric acid, it is resolved into phthalic acid and γ-amidobutyric acid, NH2·CH2·CH2·CH2·COOH.]
1900 Jrnl. Chem. Soc. 78 i. 557 When pyrrolidone is boiled with alkalis, concentrated hydrochloric acid, or barium hydroxide, it is converted into γ-aminobutyric acid.
1975 W. R. Uttal Cellular Neurophysiol. ix. 196 Substances that have classically been considered to be solely inhibitory in mammalian brains include the amino acids glycine and GABA (gamma aminobutyric acid).
2012 Los Angeles Times (Nexis) 6 Feb. d8 Studies by scientists..showed that yoga boosted brain levels of the neurotransmitter gamma-aminobutyric acid. Low GABA levels have been linked to depression.
gamma cellulose n. the portion of a cellulosic material that is soluble in alkaline solution and is not re-precipitated by acids.See also alpha cellulose n. at alpha n. and adj. Compounds 2a, beta cellulose n. at beta n. Additions.
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1912 C. F. Cross & E. J. Bevan Res. Cellulose III. ii. 23 The cellulose is fractionated by this treatment into:—α cellulose... β cellulose: soluble and reprecipitated by acids... γ cellulose: not reprecipitated: permanently soluble.
1947 J. Grant Wood Pulp & Allied Products (ed. 2) iii. 28 The point to be emphasized at this stage is that alpha-, beta- and gamma-celluloses have not been proved to be definite compounds..they are merely names given to the products obtained when the analytical operations described in chapter xvii are carried out.
2003 B. Lavédrine et al. Guide Preventive Conservation Photograph Coll. 23 Alpha cellulose must be present in a high proportion in photographic paper, whereas the beta and gamma cellulose content must be less than 4%.
gamma globulin n. Biochemistry and Medicine the fraction of serum globulin which migrates most slowly on electrophoresis; a protein belonging to this fraction; spec. = immunoglobulin n.
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1937 A. Tiselius in Biochem. Jrnl. 31 1466 The fastest of these components could be identified with serum albumin. The other three..are more or less completely precipitated by half saturation with ammonium sulphate. They will therefore be named α, β, and γ serum-globulin.]
1937 A. Tiselius in Biochem. Jrnl. 31 1473 The β- and γ- globulins gave rather diffuse boundaries.
1960 M. E. Florey Clin. Appl. Antibiotics II. vii. 202 Gamma globulin has been considered to play a part in enhancing the effect of antibiotic therapy.
2008 N.Y. Rev. Bks. 23 Oct. 24/3 Intravenous gamma globulin..is used in several different immunologically mediated disorders.
gamma-hydroxybutyrate n. Chemistry a salt or ester of 4-hydroxybutanoic acid (cf. hydroxybutyrate n. at hydroxy- comb. form Additions); esp. the sodium salt, used as a recreational drug and (formerly) as an anaesthetic (see GHB n.).
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1913 T. A. Henry Plant Alkaloids ii. 23 C4H7O3K Potassium γ-hydroxybutyrate.
1964 Science 6 Mar. 1045/2 Gamma-hydroxybutyrate, a normal metabolite in brain, is apparently unique among natural intermediates in that it has anesthetic properties.
2000 Independent 1 June i. 3/1 The Leeds Health Authority said it was ‘extremely concerned’ about Gamma-hydroxybutyrate, better known as GHB or liquid ecstasy.
2004 M. Beckerman Generation S.L.U.T. 45 Trevor poured five shots of Malibu into a glass..then added twelve milligrams of gamma hydroxybutyrate from a vial hidden in his tuxedo pocket.
gamma-linolenic acid n. [after German γ-Linolensäure (A. Heiduschka & K. Lüft 1919, in Arch. der Pharm. 257 37); compare linolenic acid n.] Chemistry an omega-6 fatty acid which is found in evening primrose, safflower, and other plant-seed oils, is a metabolic precursor of arachidonic acid and prostaglandins, and has been used as a dietary supplement in the management of premenstrual syndrome and various other (mainly chronic inflammatory) disorders; abbreviated GLA; also called gamolenic acid.Systematic name: all-cis-6,9,12-octadecatrienoic acid; C18H30O2.
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1919 Jrnl. Chem. Soc. 116 i. 372 A sparingly soluble hexabromo-γ-linolenic acid..separated which, when treated with zinc and alcohol, yielded γ-linolenic acid as a yellow substance of unpleasant odour.
1962 Brit. Med. Jrnl. 30 June 1831/1 Thomasson list nine [essential fatty acids], of which one—γ-linolenic acid—is well known to have greater potency than linoleic.
1982 BioScience 32 247/3 Who knows which of the evening primroses of the US may provide the richest source of gamma-linolenic acid?
2003 S. J. Segal & L. Mastroianni Hormone Use Menopause & Male Andropause 56 Evening primrose, also called evening star, is rich in gamma-linolenic acid.
This entry has been updated (OED Third Edition, March 2013; most recently modified version published online June 2022).
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