rarefaction


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rarefaction

[¦rer·ə¦fak·shən]
(acoustics)
The instantaneous, local reduction in density of a gas resulting from passage of a sound wave, or the region in which the density is reduced at some instant. Also known as rarefraction.
References in periodicals archive ?
Moderate-to-severe white matter rarefaction and arteriolosclerosis occurred frequently (46.6 and 47.2 percent, respectively), while infarcts, microinfarcts, and microbleeds did not.
Models and estimators linking individual-based and sample based rarefaction, extrapolation and comparison of assemblages.
The flow contains a strong shock wave, a rarefaction wave and a contact discontinuity between them.
Further, rarefaction curves showed that many more morphospecies would be identified with increased sampling across all height classes.
Antihypertensive treatment improves microvascular rarefaction and reactivity in low-risk hypertensive individuals.
A rarefaction curve was built with the numbers of selected individuals from a sample with certain quantity and species numbers counted from the individuals represented.
By solving the above problem, we obtain the constant state solution (u, [rho]) = constant, and the rarefaction wave solution
Rarefaction methods, both sample-based and individual-based, allow for meaningful standardization and comparison of datasets [51] and have been used on bird counts [e.g., [55]].
Reflecting the higher richness and higher numbers of rare OTUs, the rarefaction curve of the vegetative stage did not reach complete saturation considering the number of sequences sampled, indicating that additional OTUs will likely be detected with additional sequencing.
Especially, when [u.sub.+] [less than or equal to] 0 [less than or equal to] [u.sub.-], the two-shock solution of (1) and (2) tends to the delta-shock solution of (3) and (2), where the intermediate density between the two shocks tends to a weighted [delta]-measure which forms the delta-shock; by contrast, when [u.sub.+] [greater than or equal to] 0 [greater than or equal to] [u.sub.-], the two-rarefaction-wave solution of (1) and (2) tends to the two-contact-discontinuity solution of (3) and (2), in which the nonvacuum intermediate state between the two rarefaction waves tends to a vacuum state.
Capillary rarefaction was defined as the lower tertile of a population consisting of 250 otherwise healthy, except for the high blood pressure, individuals.
Rarefaction curves with chao1 and Shannon diversity were plotted with the average number of OTUs at each interval against the size of the subsample [27] (Figure 4).