Since the non-normality of treatment variables was confirmed using the Shapiro-Wilk test, correlations between the predictor variables including treatment variables and child/mother measures at T1, and score changes between T1 and T2 were examined by calculating Spearman's correlation coefficients.
Toxicity induced by 6-OHDA was also accompanied by an increase in nitrite production (Fig. 3C, lower panel), and its concentration was brought toward normality after S14 treatment, indicating that this drug blocks 6-OHDA-induced oxidative stress, which leads to free radical generation.
The assumptions that are made when using ANCOVA (i.e. normality of scores at treatment levels, homogeneity of variance, homogeneity of regression slopes, linear regression) will be assessed.
Ivanova [2003. A play-the-winner-type urn model with reduced variability. Metrika 58, 1 13] obtained the asymptotic normality only for two treatments.
Prior to analysis, data on sperm counts were log transformed to improve normality, and differences between treatments (familiar vs. unfamiliar, matched for mating status and oestrus stage; and early vs. late oestrus stage, matched for familiarity and mating status) were tested using paired Student's t-tests.
Hence, to power a trial to test the null hypothesis of equality of the treatments, assuming approximate normality for the VAS, would require 132 patients in each treatment arm or 264 in total assuming 90% power, 5% significance, a SD of 3 cm and an MCID of 12 mm.
The normal distributions of the values for each group (day and night for each treatment) were also tested using various normality tests (KS normality tests, D'Agostino and Pearson omnibus normality tests, Shapiro-Wilk normality tests).
If they passed, then a one-way analysis of variance (ANOVA) was performed to assess the differences in the values among the treatment groups; where normality failed, ANOVA was performed using a Kruskal Wallis analysis on ranks.
Elevated frequencies of total CD8+ T cells in PAT compared to PDT, may represent a tendency of these cells to reestablish levels of normality at the end of treatment and could be associated to clinical cure.
ANOVA was used in all measurements to compare the treatments and the normality of residuals was tested using GenStat software (14th edition).
