In the case of WUEi, peak values occurred in the first generation of breeding for both populations, when stomatal conductance was low in comparison with the second generation of breeding; however, the overall generations-within-populations effect was non-significant (P = 0.14).
That is, all studies are viewed as estimating a common, or fixed, population effect size.
This meta-analysis estimated the population effect size for Pilates effects on mental health outcomes.
Furthermore, (T_{j}^{2}) explicitly models the fact that the true population effect for a certain relation is not unique, but varies across primary studies (between-study variation).
A 95% confidence interval around the overall mean - C lower = 0.53 and C upper = 0.66 - indicated nonzero population effect and relative precision.
Given a sufficiently large sample size, a statistical comparison will always show a significant difference unless the population effect size is exactly zero.
The scientific contribution of the Cuban strategy could support a paradigm shift from individual protection to a population effect based on a rigorous body of scientific evidence.
In our experiments we found a significant population effect (Fig. 2 and 3), possibly due to different degrees of inbreeding and inbreeding depression between populations.
As detailed in the Methods section, this model relies on the estimation, through a logistic regression, of both a "locus effect" and a "population effect" on genetic differentiation.
