Heritability is estimated as the ratio of VA to the total variance Vp (Vp = VA + VE + Ve) and can be interpreted as the proportion of total variance stemming from among-individual variance that derives from the pedigree.
This owes in part to the non-linear nature of the link function, non-constant residual variance stemming from the mean-variance link, and the resulting lack of closed-form expressions for the marginal correlations.
Then, to illustrate the statistical fundaments for the transcriptogram method, we consider gene expression from different microarray experiments and calculate the variance stemming from the variability in the technique and then that originating in the biological variance.
People who still believe the outdated notion that mental health conditions are "all in a person's head" have yet another reason to stop believing the myth: According to a new study in the journal Current Biology, those with anxiety perceive the world differently -- and it stems from a variance in their brains.
Fitness variance owing to maternal effects is also now widely recognized (Mousseau and Fox, 1998) and fitness variance stemming from the interaction between maternal and offspring phenotypes is also known (Moore et al., 1997, 1998; Wolf and Brodie, 1998; Wolf et al., 1999a; Wolf, 2000).
Random errors (37.1% of total variance) stemming from selection process (Operator) because of the enormity of food items listed in the database and system errors (59.5% of total variance) due to measurements (units, tools and procedures) variations.
We were interested in the amount of heterogeneity, i.e. of additional variance stemming from differences between centres.
The covariance between alleles stemming from LD complicates the variance assessment, and epistatic effects, i.e., interactions between causal loci are often ignored.
Besides a potential inflation of marker-explained variance stemming from LD between markers, it should also be noted that the detection of imprinting relies mainly on the comparison between heterozygotes, which might be confounded by dominance under some circumstances.
Note also that each of these factors contains a contribution stemming from a change in the variance of concentration fluctuations and another one reflecting the change in the mean of the concentrations.
