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  • Author: Zahra Montazeri x
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Research on analyzing microarray data has focused on the problem of identifying differentially expressed genes to the neglect of the problem of how to integrate evidence that a gene is differentially expressed with information on the extent of its differential expression. Consequently, researchers currently prioritize genes for further study either on the basis of volcano plots or, more commonly, according to simple estimates of the fold change after filtering the genes with an arbitrary statistical significance threshold. While the subjective and informal nature of the former practice precludes quantification of its reliability, the latter practice is equivalent to using a hard-threshold estimator of the expression ratio that is not known to perform well in terms of mean-squared error, the sum of estimator variance and squared estimator bias. On the basis of two distinct simulation studies and data from different microarray studies, we systematically compared the performance of several estimators representing both current practice and shrinkage. We find that the threshold-based estimators usually perform worse than the maximum-likelihood estimator (MLE) and they often perform far worse as quantified by estimated mean-squared risk. By contrast, the shrinkage estimators tend to perform as well as or better than the MLE and never much worse than the MLE, as expected from what is known about shrinkage. However, a Bayesian measure of performance based on the prior information that few genes are differentially expressed indicates that hard-threshold estimators perform about as well as the local false discovery rate (FDR), the best of the shrinkage estimators studied. Based on the ability of the latter to leverage information across genes, we conclude that the use of the local-FDR estimator of the fold change instead of informal or threshold-based combinations of statistical tests and non-shrinkage estimators can be expected to substantially improve the reliability of gene prioritization at very little risk of doing so less reliably. Since the proposed replacement of post-selection estimates with shrunken estimates applies as well to other types of high-dimensional data, it could also improve the analysis of SNP data from genome-wide association studies.



Parents play a significant role in promoting of healthy sexuality in adolescents. The purpose of the present study was to assess the effectiveness of a sexuality education intervention program to enhance parent–adolescent sexual communication.


This study was a randomized controlled field trial. Parents of male adolescent aged 13–16 years were recruited from eight public all-boys high schools in Karaj, Iran. A multi-stage stratified random sampling method was used and 102 parents were assigned into intervention and control groups. The recruitment and data collection process lasted from February to November 2019. Self-report demographic questionnaire and six general parenting and parent–adolescent sexual communication measures were used to assess the impact of intervention. Sexuality education program was presented for the parents of intervention group, in the form of four weekly 2-h sessions. Parents were assessed at the baseline, within one week post-intervention, and three-month follow-up to evaluate the outcome variables. The data were analyzed using the Chi-square test, two-sample t-test, general linear model analyses, and Bonferroni test.


In terms of parent–adolescent general communication, parental monitoring, parent–adolescent communication about sex-related topics, parent’s sexual communication skills, parent’s self-efficacy, and responsiveness to sexual communication. There were no significant differences between intervention and control groups at the baseline (p>0.05). Compared to controls, intervention parents reported more improvement in general communication across the time; however, significant differences were not observed regarding general communication and parental monitoring (p=0.94, p=0.95). Parents in the intervention group significantly differed from those in the control group for the mean scores of parent–adolescent communication about sex-related topics (p=0.04), parent’s sexual communication skills (p=0.04), parent’s self-efficacy (p=0.002), and responsiveness (p<0.001) to sexual communication at each follow-up.


We identified the educational program as a promising tool for improving parent–adolescent communication regarding sexuality-related issues. This program provides the evidence for implementation of parent-based sexuality education programs.