| log | Formally, the number of times ten must be multiplied with itself to equal a certain number. For example: 100,000 is log 5 because it is equal to 10 x 10 x 10 x 10 x 10. Logs are used to measure changes in viral load (see). For example: a reduction in viral load from 100,000 to 1,000 copies/ml is a two log (or 99 percent) reduction. Note that a half log change is not a five-fold difference but a change of 3.16-fold (the square root of ten). (09 Oct 1997) |
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| log choker | A length of cable or chain that is wrapped around a log or harvested tree to secure the log to the winch cable of a skidder or to an overhead cable yarding line. (05 Dec 1998) |
| logagnosia | <clinical sign, neurology> A defect or loss of the ability to speak or write, loss of ability to understand spoken or written language, due to injury or disease of the brain centres. Origin: Gr. Phasis = speech (16 Dec 1997) |
| logagraphia | <neurology> Loss of ability to write (a form of aphasia). Symptom common to tumours of the parietal lobe of the dominant cerebral hemisphere. (16 Dec 1997) |
| logamnesia | <clinical sign, neurology> A defect or loss of the ability to speak or write, loss of ability to understand spoken or written language, due to injury or disease of the brain centres. Origin: Gr. Phasis = speech (16 Dec 1997) |
| Logan, William | <person> Early 20th century U.S. Plastic surgeon. See: Logan's bow. (05 Mar 2000) |
| logaphasia | Aphasia of articulation. Origin: Logo-+ G. Aphasia, speechlessness (05 Mar 2000) |
| logarithm | <mathematics> One of a class of auxiliary numbers, devised by John Napier, of Merchiston, Scotland (1550-1617), to abridge arithmetical calculations, by the use of addition and subtraction in place of multiplication and division. The relation of logarithms to common numbers is that of numbers in an arithmetical series to corresponding numbers in a geometrical series, so that sums and differences of the former indicate respectively products and quotients of the latter; thus 0 1 2 3 4 Indices or logarithms 1 10 100 1000 10,000 Numbers in geometrical progression Hence, the logarithm of any given number is the exponent of a power to which another given invariable number, called the base, must be raised in order to produce that given number. Thus, let 10 be the base, then 2 is the logarithm of 100, because 10^2 = 100, and 3 is the logarithm of 1,000, because 10^3 = 1,000. Arithmetical complement of a logarithm, the difference between a logarithm and the number ten. Binary logarithms. See Binary. Common logarithms, or Brigg's logarithms, logarithms of which the base is 10; so called from Henry Briggs, who invented them. Gauss's logarithms, tables of logarithms constructed for facilitating the operation of finding the logarithm of the sum of difference of two quantities from the logarithms of the quantities, one entry of those tables and two additions or subtractions answering the purpose of three entries of the common tables and one addition or subtraction. They were suggested by the celebrated German mathematician Karl Friedrich Gauss (died in 1855), and are of great service in many astronomical computations. Hyperbolic, or Napierian, logarithms, those logarithms (devised by John Speidell, 1619) of which the base is 2.7182818; so called from Napier, the inventor of logarithms. Logistic or Proportionallogarithms. Origin: Gr. Word, account, proportion + number: cf. F. Logarithme. Source: Websters Dictionary (01 Mar 1998) |
| logarithmic phase | <cell culture> The steepest slope of the growth curve of a culture--the phase of vigorous growth during which cell number doubles every 20-30 minutes. (15 Nov 1997) |
| logarithmical | Of or pertaining to logarithms; consisting of logarithms. <mathematics> Logarithmic curve, a curve which, referred to a system of rectangular coordinate axes, is such that the ordinate of any point will be the logarithm of its abscissa. Logarithmic spiral, a spiral curve such that radii drawn from its pole or eye at equal angles with each other are in continual proportion. See Spiral. Origin: F. Logarithmique. Source: Websters Dictionary (01 Mar 1998) |
| logasthenia | <clinical sign, neurology> A defect or loss of the ability to speak or write, loss of ability to understand spoken or written language, due to injury or disease of the brain centres. Origin: Gr. Phasis = speech (16 Dec 1997) |
| logcock | <ornithology> The pileated woodpecker. Source: Websters Dictionary (01 Mar 1998) |
| logetronography | <photography> A method of photographic printing in which fine details are emphasized by electronic enhancement of their contrast; formerly used for reproducing radiographic images. (05 Mar 2000) |
| loggat | 1. A small log or piece of wood. 2. An old game in England, played by throwing pieces of wood at a stake set in the ground. Origin: Also written logget. Source: Websters Dictionary (01 Mar 1998) |
| loggerhead | 1. A blockhead; a dunce; a numskull. 2. A spherical mass of iron, with a long handle, used to heat tar. 3. An upright piece of round timber, in a whaleboat, over which a turn of the line is taken when it is running out too fast. 4. <zoology> A very large marine turtle (Thalassochelys caretta, or caouana), common in the warmer parts of the Atlantic Ocean, from Brazil to Cape Cod; called also logger-headed turtle. 5. <zoology> An American shrike (Lanius Ludovicianus), similar to the butcher bird, but smaller. See Shrike. To be at loggerheads, To fall to loggerheads, or To go to loggerheads, to quarrel; to be at strife. Origin: Log + head. Source: Websters Dictionary (01 Mar 1998) |
| butt log | The log taken from the base of a tree; often slightly irregular. (05 Dec 1998) |
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