A note on Poisson goodness-of-fit tests for ionizing radiation induced chromosomal aberration samples

Abstract

Purpose: To present Poisson exact goodness-of-fit tests as alternatives and complements to the asymptotic u-test, which is the most widely used in cytogenetic biodosimetry, to decide whether a sample of chromosomal aberrations in blood cells comes from an homogeneous or inhomogeneous exposure. Results: It is observed how the u-test is not an appropriate approximation in small samples with small yield of chromosomal aberrations. Tools are provided to compute the three exact tests, which is not as trivial as the implementation of the u-test. Materials and Methods Conclusions:Poisson exact goodness-of-fit tests should be considered jointly to the u-test for detecting inhomogeneous exposures in the cytogenetic biodosimetry practice.

Manual Scoring with Shortened 48 h Cytokinesis-Block Micronucleus Assay Feasible for Triage in the Event of a Mass-Casualty Radiation Accident

“…Poisson distribution was first verified in observed MN distributions with GOF Poisson R files kindly provided by M. Higueras. The R files are based on the same Shiny R application developed by Ferna ´ndez-Fontelo et al and Higueras et al (37,38). The dispersion index and results from over-dispersion (u test), zero-inflated Poisson (ZIP) (Ztest) and Bayesian (ZIP versus Poisson) tests were reported (39)(40)(41)(42).…”

A High Throughput Approach to Reconstruct Partial-Body and Neutron Radiation Exposures on an Individual Basis

“…Biodosimetric panels using other types of biomarkers are also being developed [57][58][59][60][61][62][63][64][65][66][67][68][69] . Cytogenetic damage per cell distribution shapes are commonly modeled by Poisson, Negative Binomial or Neyman distributions 37,40,[70][71][72] , and it is well known that these shapes can change depending on exposure type due to the shielding and/or differences in radiation track structure and energy deposition patterns. For example, densely ionizing radiations like neutrons tend to produce "overdispersed" distributions of cytogenetic damage, where the ratio of variance/mean becomes significantly higher than in a standard Poisson distribution (e.g.…”

Cytogenetic effects in cancer patients lymphocytes depending on the radiation source and the locality of radiation exposure in experiment ex vivo

“…Стандартні похибки середніх рівнів цитогенетичних пошкоджень (SE) обчислювали з урахуванням дисперсії поклітинних розподілів аберацій (σ 2 ) в об"єднаних вибірках метафаз. Оцінку рандомізованості поклітинного розподілу аберацій хромосом проводили за відношенням дисперсії до середнього (σ 2 /Y) та за u-тестом Папворта (u) [15]. Вірогідність різниці між середніми значеннями цитогенетичних показників визначали за t-критерієм Стьюдента [16].…”