We then analyzed the effects of the GM maize varieties on each sex and each diet by pairwise comparisons of the parameters of GM-fed rats versus control groups, and subsequently to the unrelated non-GM maize reference groups. The statistical differences between reference and control groups were calculated in order to study the effects of the different normal diets per se (due to differences in salts, sugars, minerals, vitamins, pesticides, etc composition), and indicated by contrast to Monsanto's work (see legend Table 1 ). In order to select the appropriate two-tailed comparison test [ 7 ], we again studied first normality (Shapiro test) and variance equality (F test). According to the results, we performed the adapted test; that is, an unpaired t test, a Welch corrected t test or a Mann-Whitney test (which is generally more appropriate with a sample size of 10). To perform multiple pairwise comparisons, we used the False Discovery Rate approach (FDR, [ 9 ]) to calculate adjusted p-values, in order to limit the rate of false positives to 5%. We preferred Benjamini and Yekutieli's method [ 10 ] rather than that of Benjamini and Hochberg [ 11 ] as the parameters under investigation are not independent. In addition, after centering and scaling the data, Principal Components Analysis (PCA, [ 12 ]) was performed in order to study the scattering of the different factors (sex, period, diet, dose and group). Finally, we established per group for each rat and by parameter the representations and paired tests corresponding to the temporal changes between the two feeding periods.
But others disagree. Calling the problem runner’s face is a misnomer, says Kevin Burns, licensed fitness instructor and American Council on Exercise spokesperson. He says that the loss of facial fatty tissue is just as likely to be caused by a strict diet or a different form of rigorous exercise. He acknowledges that this can lead to a more angular appearance in older runners, but that’s no reason to stop working out. “Comments like Glatt’s aren’t doing very good things for the running community or for physical activity at large,” according to Burns.