The implementation of random survival forests in conflict management data: An examination of power sharing and third party mediation in post-conflict countries.

Time-to-event analysis is a common occurrence in political science. In recent years, there has been an increased usage of machine learning methods in quantitative political science research. This article advocates for the implementation of machine learning duration models to assist in a sound model selection process.

Poor maternal nutrition during gestation in sheep alters prenatal muscle growth and development in offspring.

Poor maternal nutrition during gestation can have immediate and life-long negative effects on offspring growth and health. In livestock, this leads to reduced product quality and increased costs of production. Based on previous evidence that both restricted- and overfeeding during gestation decrease offspring muscle growth and alter metabolism postnatally, we hypothesized that poor maternal nutrition during gestation would reduce the growth and development of offspring muscle prenatally, reduce the number of myogenic progenitor cells, and result in changes in the global expression of genes involved in prenatal muscle development and function.

MicroRNA-messenger RNA interactions involving JAK-STAT signaling genes in colorectal cancer.

JAK-STAT signaling influences many downstream processes that, unchecked, contribute to carcinogenesis and metastasis. MicroRNAs (miRNAs) are hypothesized as a mechanism to prevent uncontrolled growth from continuous JAK-STAT activation. We investigated differential expression between paired carcinoma and normal colorectal mucosa of messenger RNAs (mRNAs) and miRNAs using RNA-Seq and Agilent Human miRNA Microarray V19.

Power in pairs: assessing the statistical value of paired samples in tests for differential expression.

Background: When genomics researchers design a high-throughput study to test for differential expression, some biological systems and research questions provide opportunities to use paired samples from subjects, and researchers can plan for a certain proportion of subjects to have paired samples. We consider the effect of this paired samples proportion on the statistical power of the study, using characteristics of both count (RNA-Seq) and continuous (microarray) expression data from a colorectal cancer study.

Results: We demonstrate that a higher proportion of subjects with paired samples yields higher statistical power, for various total numbers of samples, and for various strengths of subject-level confounding factors.

miRNA involvement in cell cycle regulation in colorectal cancer cases.

Uncontrolled cell replication is a key component of carcinogenesis. MicroRNAs (miRNAs) regulate genes involved in checkpoints, DNA repair, and genes encoding for key proteins regulating the cell cycle. We investigated how miRNAs and mRNAs in colorectal cancer subjects interact to regulate the cell cycle.

Expression of Wnt-signaling pathway genes and their associations with miRNAs in colorectal cancer.

The Wnt-signaling pathway functions in regulating cell growth and thus is involved in the carcinogenic process of several cancers, including colorectal cancer. We tested the hypothesis that multiple genes in this signaling pathway are dysregulated and that miRNAs are associated with these dysregulated genes. We used data from 217 colorectal cancer (CRC) cases to evaluate differences in Wnt-signaling pathway gene expression between paired CRC and normal mucosa and identify miRNAs that are associated with these genes.

Infrequently expressed miRNAs in colorectal cancer tissue and tumor molecular phenotype.

This corrects the article DOI: 10.1038/modpathol.2017.

MicroRNA-transcription factor interactions and their combined effect on target gene expression in colon cancer cases.

Transcription factors (TFs) and microRNAs (miRNAs) regulate gene expression: TFs by influencing messenger RNA (mRNA) transcription and miRNAs by influencing mRNA translation and transcript degradation. Additionally, miRNAs and TFs alter each other's expression, making it difficult to ascertain the effect either one has on target gene (TG) expression. In this investigation, we use a two-way interaction model with the TF and miRNA as independent variables to investigate whether miRNAs and TFs work together to influence TG expression levels in colon cancer subjects.

The NF-κB signalling pathway in colorectal cancer: associations between dysregulated gene and miRNA expression.

Background: The nuclear factor-kappa B (NF-κB) signalling pathway is a regulator of immune response and inflammation that has been implicated in the carcinogenic process. We examined differentially expressed genes in this pathway and miRNAs to determine associations with colorectal cancer (CRC).

Methods: We used data from 217 CRC cases to evaluate differences in NF-κB signalling pathway gene expression between paired carcinoma and normal mucosa and identify miRNAs that are associated with these genes.

Infrequently expressed miRNAs influence survival after diagnosis with colorectal cancer.

Half of miRNAs expressed in colorectal tissue are expressed < 50% of the population. Many infrequently expressed miRNAs have low levels of expression. We hypothesize that less frequently expressed miRNAs, when expressed at higher levels, influence both disease stage and survival after diagnosis with colorectal cancer (CRC); low levels of expression may be background noise.

Identifying factors associated with the direction and significance of microRNA tumor-normal expression differences in colorectal cancer.

Background: microRNAs are small non-protein-coding RNA molecules that regulate gene expression, and have a potential epigenetic role in disease progression and survival of colorectal cancer. In terms of tumor-normal expression differences, many microRNAs exhibit evidence of being up-regulated in some subjects but down-regulated in others, or are dysregulated only for a subset of the population. We present and implement an approach to identify factors (lifestyle, tumor molecular phenotype, and survival-related) that are associated with the direction and/or significance of these microRNAs' tumor-normal expression differences in colorectal cancer.

The PI3K/AKT signaling pathway: Associations of miRNAs with dysregulated gene expression in colorectal cancer.

The PI3K/AKT-signaling pathway is one of the most frequently activated signal-transduction pathways in cancer. We examined how dysregulated gene expression is associated with miRNA expression in this pathway in colorectal cancer (CRC). We used data from 217 CRC cases to evaluate differential pathway gene expression between paired carcinoma and normal mucosa and identify miRNAs that are associated with these genes.

A Bivariate Hypothesis Testing Approach for Mapping the Trait-Influential Gene.

The linkage disequilibrium (LD) based quantitative trait loci (QTL) model involves two indispensable hypothesis tests: the test of whether or not a QTL exists, and the test of the LD strength between the QTaL and the observed marker. The advantage of this two-test framework is to test whether there is an influential QTL around the observed marker instead of just having a QTL by random chance. There exist unsolved, open statistical questions about the inaccurate asymptotic distributions of the test statistics.

: A Microbial Community Analysis Tool to Identify and Visualize Significantly Responsive Branches in a Phylogenetic Tree.

Microbial community analysis experiments to assess the effect of a treatment intervention (or environmental change) on the relative abundance levels of multiple related microbial species (or operational taxonomic units) simultaneously using high throughput genomics are becoming increasingly common. Within the framework of the evolutionary phylogeny of all species considered in the experiment, this translates to a statistical need to identify the phylogenetic branches that exhibit a significant consensus response (in terms of operational taxonomic unit abundance) to the intervention. We present the R software package , a collection of flexible tools that make use of meta-analysis methods and regular expressions to identify and visualize significantly responsive branches in a phylogenetic tree, while appropriately adjusting for multiple comparisons.

An Assessment of Database-Validated microRNA Target Genes in Normal Colonic Mucosa: Implications for Pathway Analysis.

Background: Determination of functional pathways regulated by microRNAs (miRNAs), while an essential step in developing therapeutics, is challenging. Some miRNAs have been studied extensively; others have limited information. In this study, we focus on 254 miRNAs previously identified as being associated with colorectal cancer and their database-identified validated target genes.

Transcription factor-microRNA associations and their impact on colorectal cancer survival.

MicroRNAs (miRNAs) and Transcription Factors (TFs) both influence messenger RNA (mRNA) expression, disrupting biological pathways involved in carcinogenesis and prognosis. As many miRNAs target multiple mRNAs, thus influencing a multitude of biological pathways, deciphering which miRNAs are important for cancer development and survival is difficult. In this study, we (i) determine associations between TF and survival (N = 168 colon cancer cases); (ii) identify miRNAs associated with TFs related to survival; and (iii) determine if factors derived from TF-specific miRNA principal component analysis (PCA) influence survival.

Infrequently expressed miRNAs in colorectal cancer tissue and tumor molecular phenotype.

We have previously shown that commonly expressed miRNAs influenced tumor molecular phenotype in colorectal cancer. We hypothesize that infrequently expressed miRNAs, when showing higher levels of expression, help to define tumor molecular phenotype. In this study, we examine 304 miRNAs expressed in at least 30 individuals, but in <50% of the population and with a mean level of expression above 1.

A comparison of multiple testing adjustment methods with block-correlation positively-dependent tests.

In high dimensional data analysis (such as gene expression, spatial epidemiology, or brain imaging studies), we often test thousands or more hypotheses simultaneously. As the number of tests increases, the chance of observing some statistically significant tests is very high even when all null hypotheses are true. Consequently, we could reach incorrect conclusions regarding the hypotheses.

Alterations in microRNA expression associated with alcohol consumption in rectal cancer subjects.

Purpose: Alcohol consumption has been purported to influence many diseases. MicroRNAs (miRNAs) may be influenced by compounds found in alcohol. In this investigation, we test the hypothesis that total alcohol, beer, wine, and hard liquor influence miRNA expression.

Genetic variants in the TGFβ-signaling pathway influence expression of miRNAs in colon and rectal normal mucosa and tumor tissue.

The TGF-β signaling pathway is involved in regulation of cell growth, angiogenesis, and metastasis. We test the hypothesis that genetic variation in the TGF-β signaling pathway alters miRNA expression.We use data from 1188 colorectal cancer cases to evaluate associations between 80 SNPs in 21 genes.

Diet and lifestyle factors associated with miRNA expression in colorectal tissue.

MicroRNAs (miRNAs) are small non-protein-coding RNA molecules that regulate gene expression. Diet and lifestyle factors have been hypothesized to be involved in the regulation of miRNA expression. In this study it was hypothesized that diet and lifestyle factors are associated with miRNA expression.

The miRNA landscape of colorectal polyps.

The genomic landscape of adenomas and polyps may help define disease pathways. Expression of miRNAs in adenomas and polyps may importantly contribute to these pathways. We evaluated miRNA expression in 293 polyp-normal colorectal mucosa pairs.

Association of cigarette smoking and microRNA expression in rectal cancer: Insight into tumor phenotype.

Smoking is known to influence messenger RNA (mRNA) expression in colorectal cancer (CRC) cases. As microRNAs (miRNAs) are known repressors of mRNAs, we hypothesize that smoking may influence miRNA expression, thus altering mRNA expression. Our sample consisted of 1447 CRC cases that had normal colorectal mucosa and carcinoma miRNA data and lifestyle data.

Site-specific associations between miRNA expression and survival in colorectal cancer cases.

Background: MicroRNAs (miRNA) are small non-coding RNA involved in cellular processes, including cell proliferation and angiogenesis. Thus, miRNA expression may alter survival after diagnosis with colorectal cancer (CRC).

Results: Individuals diagnosed with stage 1 or stage 2 rectal cancer had worse survival than colon cancer cases diagnosed at stage 1 or stage 2.

Increased Susceptibility to Atrial Fibrillation Secondary to Atrial Fibrosis in Transgenic Goats Expressing Transforming Growth Factor-β1.

Introduction: Large animal models of progressive atrial fibrosis would provide an attractive platform to study relationship between structural and electrical remodeling in atrial fibrillation (AF). Here we established a new transgenic goat model of AF with cardiac specific overexpression of TGF-β1 and investigated the changes in the cardiac structure and function leading to AF.

Methods And Results: Transgenic goats with cardiac specific overexpression of constitutively active TGF-β1 were generated by somatic cell nuclear transfer.