Spss v20

The two‐tailed student's t‐test (IBM spss, v.20, IBM, Armonk, NY, USA) was used to compare the means among Q4 versus Q1 samples, with acceptable Benjamini false discovery rate (FDR) of less than 0·05. Linear regression analysis (IBM spss, v.20) was performed to study the correlation of the differences among various gene sets. Overall survival (OS) was measured from the date of patient enrolment to the date of death. Event‐free survival (EFS) was measured from the date of patient enrolment to the date of failure to achieve complete remission, relapse from complete remission or death. Relapse‐free survival (RFS) was measured from the date of complete remission to the date of relapse or death. Cox regression test (IBM SPSS, v.20) was used for univariate and multivariate analysis of survival in the classifier and validation AML series. Univariate Cox regression analysis was performed using each of the potentially implicated variables. Multivariate Cox regression analysis was performed using all variables with P < 0·1 in univariate analyses. Kaplan–Meier analysis was performed using Mantel‐Cox statistic (IBM spss, v.20) in order to test the equality of survival distributions for the different levels of the classifier in both the classifier and validation AML series.

One-way ANOVA was used to identify the statistical significance of the pH value within each group along the incubation time. The differences of alpha diversity index, as well as the q-PCR abundance of bacteria, archaea, and methanogens, between the control and treatment groups was evaluated by Independent-Samples t-test (SPSS v20.0) at a single time point. Heatmaps representing the relative sequence abundances of bacterial OTUs among the samples were constructed using the “pheatmap” and “gplots” packages. Significantly enriched microbial taxa during the treatment was evaluated by Independent-Samples t-test (SPSS v20.0) at each time point. The relationships between relative abundance and incubation time for each group were then explored with four models, linear, quadratic, exponential, and logarithmic regression. The best models were selected based on Akaike’s information criterion (AIC, Bozdogan, 1987 (link)). Permutational multivariate analysis of variance (PERMANOVA) (Anderson, 2001 (link)) was performed using the adonis function in the Vegan package (R studio, version 2.14.1, R Development Core Team, 2011 ) to evaluate the two-sided effects of Microcystis addition and incubation time on microbial community dynamics. The correlation between methane concentration and methanogen abundance was measured by Pearson correlation coefficient (r-value, SPSS v20.0).

A Shapiro-Wilk test indicated that the assumptions of normality were violated (p < 0.05, SPSS v. 20.0); therefore, differences among treatments and among sampling weeks were tested using the non-parametric one-way Kruskal-Wallis test (SPSS v.20.0). Significant results were further tested by pairwise post-hoc comparisons (Mann-Whitney U test, SPSS v. 20.0), adjusted for type I error, and Similarity percentages analysis, SIMPER (PRIMER 6).