expansion

(redirected from clonal expansion)
Also found in: Dictionary, Thesaurus, Medical, Legal, Financial.
Related to clonal expansion: Clonal selection

expansion,

in physics, increase in volume resulting from an increase in temperature. Contraction is the reverse process. When heat is applied to a body, the rate of vibration and the distances between the molecules composing it are increased and, hence, the space occupied by the body, i.e., its volume, increases. This increase in volume is not constant for all substances for any given rise in temperature, but is a specific property of each kind of matter. For example, zinc and lead undergo greater expansion in a one-degree rise in temperature than do silver or brass. Since solidssolid,
one of the three commonly recognized states in which matter occurs, i.e., that state, as distinguished from liquid and gas, in which a substance has both a definite shape and a definite volume.
have a definite shape, each linear dimension of the solid increases by a proportional amount for a given temperature increase. The amount that a unit length along any direction of a substance increases for a temperature increase of one degree is called the coefficient of linear expansion of the substance. Most liquids also expand when heated. However, since liquids do not have a definite shape, it is the expansion of their volume as a whole that is relevant rather than the increase in a linear dimension. The amount of expansion that a unit volume (e.g., a cubic centimeter or a cubic foot) of any substance undergoes per one-degree rise in temperature is called its volume coefficient or coefficient of cubical expansion and is listed as a property of that substance. The coefficient of linear expansion can be calculated by dividing the coefficient of cubical expansion of the substance by three. When the amount of expansion of a given length of a substance has been determined experimentally, the linear coefficient is calculated by dividing the total amount of expansion by the product of the original number of length units and the number of degrees of rise in temperature. Gases also exhibit thermal expansion. The coefficient of expansion is about the same for all the common gases at ordinary temperatures; it is 1-273 of the volume at 0°C; per degree rise in temperature. The Kelvin, or absolute, scale is based upon this behavior (see Kelvin temperature scaleKelvin temperature scale,
a temperature scale having an absolute zero below which temperatures do not exist. Absolute zero, or 0°K;, is the temperature at which molecular energy is a minimum, and it corresponds to a temperature of −273.
). Charles's law concerning the expansion of gases states that the volume of a gas is directly proportional to its absolute temperature (see gas lawsgas laws,
physical laws describing the behavior of a gas under various conditions of pressure, volume, and temperature. Experimental results indicate that all real gases behave in approximately the same manner, having their volume reduced by about the same proportion of the
). Liquids differ from each other as do solids in their expansion coefficients. Water, unlike most substances, contracts rather than expands as its temperature is increased from 0°C; to 4°C;; above 4°C; it exhibits normal behavior, expanding as the temperature increases.

expansion

[ik′span·shən]
(electronics)
A process in which the effective gain of an amplifier is varied as a function of signal magnitude, the effective gain being greater for large signals than for small signals; the result is greater volume range in an audio amplifier and greater contrast range in facsimile.
(mathematics)
The expression of a quantity as the sum of a finite or infinite series of terms, as a finite or infinite product of factors, or, in general, in any extended form.
(mechanical engineering)
Increase in volume of working material with accompanying drop in pressure of a gaseous or vapor fluid, as in an internal combustion engine or steam engine cylinder.
(physics)
Process in which the volume of a constant mass of a substance increases.

expansion

The increase in length or volume of a material, or a body, caused by temperature, moisture, or other environmental condition.

expansion

1. Maths
a. the form of an expression or function when it is written as the sum or product of its terms
b. the act or process of determining this expanded form
2. the part of an engine cycle in which the working fluid does useful work by increasing in volume
3. Physics the increase in the dimensions of a body or substance when subjected to an increase in temperature, internal pressure, etc.
References in periodicals archive ?
CCAAT/enhancer-bin ding protein [beta] is required for mitotic clonal expansion during adipogenesis.
On the clonal expansion side, one example of a potentially misleading result might be in the case of benign monoclonal gammopathy--a long known and not uncommon "condition" of (as the name suggests) little clinical importance, where for unknown reasons one particular B cell clone becomes highly overrepresented.
a], there are substantial differences in predicted net displacements inside and outside of grass patches [ILLUSTRATION FOR FIGURE 6C OMITTED], and also in the power to detect treatment differences in long-term rates of clonal expansion.
Two-stage clonal expansion models of cancer that account explicitly for mutation of normal cells to initiated cells, clonal expansion of initiated cells, and mutation of initiated cells to fully malignant cells (Moolgavkar et al.
Antibiotic resistance genes can also spread through clonal expansion in successful pathogenic strains, for example, KPC in K.
The multiple somatic antigens, variety of antimicrobial drug-resistance scores, and variety of gene complements in this successful ST indicate multiple acquisitions of virulence markers, rather than clonal expansion from a single source (Table; online Technical Appendix Figure, http://wwwnc.
Molecular epidemiology of KPCproducing Klebsiella pneumoniae isolates in the United States: clonal expansion of multilocus sequence type 258.
These clades are thought to be basal to the highly fit clonal expansion on these continents.
We conclude that the relatively limited variation in clonal variants (STs) and ESBL genotypes is a consequence of recent introduction from connecting areas, such as Canada, possibly directly by bird migration or human activities, of a few resistant clones, followed by a local clonal expansion.
Outbreak of W135 meningococcal disease in 2000: not emergence of a new W135 strain but clonal expansion within the electrophoretic type-37 complex.
Serogroup W135 strains are widely distributed worldwide; the emergence of these strains during the 2000s corresponded to a clonal expansion of 1 clone within the ST11 complex (7).

Site: Follow: Share:
Open / Close