This may be because of sample heterogeneity or natural selection for larger individuals in the wild.
Indeed, gene expression profiling revealed that only 45% of these lines displayed the same subtype as the tumor of origin, probably not only because of sample heterogeneity but also due to the presence of non-neoplastic cells (inflammatory cells, reactive astrocytes, vascular cells) in the tissue samples.
Because of the sampling heterogeneity and the non-significant genetic differences observed for the Gm system among the Noir Marron communities [ 7], a Fst test on uniparental markers, using Arlequin v.3.11 software [ 17], confirmed their genetic homogeneity (Fst < 0.05, p-value = 0.05, data not shown).
That's because of sampling theory.
Pigments like minium, green earth, a lead-based yellow and smalt have been detected in the painted layer, while a precise identification of the resins and varnishes layered on top of the decoration was not possible because of the heterogeneity of samples.
The reports from previous studies were contradictory, at least partly because of issues related to sample sizes, sample heterogeneity (both in ethnic background and phenotype), population stratification, genotyping resolution, and extent of coverage.
As no intra-sample concordance results are available, the question whether these differences are because of a true discordance between primary tumour and metastases or rather due to an intra-sample variability (i.e., variability (a) between different areas within the same sample because of biological heterogeneity (Al-Mulla et al, 1998 ) or (b) to technical reproducibility) remains unanswered.
Regular exercise has often been suggested to have beneficial effects on cognition, but empirical findings are mixed because of heterogeneity in sample composition (age and sex); the cognitive domain being investigated; the definition and reliability of exercise behavior measures; and study design (e.g., observational versus experimental).
However, humidity penetrates at different degrees along the sample because of the heterogeneity of microstructure morphology and defects in the MWs (described in the "Photoluminescence Evolution of MAPbI3 Microwires Under Humidity" section of the main text and in Additional file 1: Section 2).
It is often cumbersome to reproduce the data using patient samples because of the heterogeneity.
