Avtor/Urednik		Glaser, EM; Wilson, PD
Naslov		A comparison of three estimators of the coefficient of error of optical fractionar cell count estimates
Tip		članek
Vir		Acta Stereol
Vol. in št.		Letnik 18, št. 1
Leto izdaje		1999
Obseg		str. 15-25
Jezik		eng
Abstrakt		The optical fractionator is a design-based two-stage systematic sampling method that is used to estimate the number of cells in populations that are too large to count exhaustively. It counts the cells found in optical disectors that have been systematically sampled in serial sections. Computer simulation was used to investigate three methods for estimating the coeffcient of error (CE), the precision of a population size estimate, obtained from a single optical fractionator sample. The methods were: the original estimation equation of Gundersen and Jensen (1987), its nugget effect modification (West et al., 1996), and the method of Scheaffer, Mendenhall, and Ott (1996), which has not been used in stereology. It is difficult to evaluate the estimated precision of population cell count estimates by using biological tissue samples.They do not permit a comparison of an estimated CE with the true CE. Computer simulation does permit such comparisons while avoiding the observational biases inherent in working with biological tissue. The estimated CE's were evaluated in tests of three types of non-random cell population distribution and one random cell population distribution. The non-random population distributions varied according to both section and disector location within the section. Two were sinusoidal and one was linearly increasing; in all three there was a 6-fold difference between the high and low intensities, i.e., expected cell counts per disector. The sinusoidal distributions produced either a peak or a depression of cell intensity at the center of the simulated region. The linear cell intensity gradually increased from the beginning to the end of the region that contained the cells. The random population distribution had constant cell intensity over the region. (Abstract truncated at 2000 characters).
Deskriptorji		CELL COUNT CELL SIZE COMPUTER SIMULATION IMAGE PROCESSING, COMPUTER-ASSISTED