Evaluating Bioinformatic Pipeline Performance for Forensic Microbiome Analysis*,†,‡

Microbial communities have potential evidential utility for forensic applications. However, bioinformatic analysis of high-throughput sequencing data varies widely among laboratories. These differences can potentially affect microbial community composition and downstream analyses. To illustrate the importance of standardizing methodology, we compared analyses of postmortem microbiome samples using several bioinformatic pipelines, varying minimum library size or minimum number of sequences per sample, and sample size. Using the same input sequence data, we found that three open-source bioinformatic pipelines, MG-RAST, mothur, and QIIME2, had significant differences in relative abundance, alpha-diversity, and beta-diversity, despite the same input data. Increasing minimum library size and sample size increased the number of low-abundant and infrequent taxa detected. Our results show that bioinformatic pipeline and parameter choice affect results in important ways. Given the growing potential application of forensic microbiology to the criminal justice system, continued research on standardizing computational methodology will be important for downstream applications.     

Is the internet an instrument of global democratization?

This article explores the hypothesis that people in less democratic nations will use the Internet newsgroups devoted to those countries as a relatively ‘safe’ form of political discussion and even protest. Also, it is expected that nationals of those countries living overseas will use these newsgroups to more openly discuss politics in those nations than they could otherwise do so. Before turning to a content analysis of the messages posted in non‐United States Usenet groups, the number of these groups and the levels of political discussion in them are quantified. The article quantifies the international usage of the Usenet as a first attempt to find some patterns in this usage that may be politically motivated. After all, many pundits imagine that the Internet will become the vaunted ‘global village’ and source of ‘grass‐roots democracy’, and not merely in the United States. An examination of the content of about 2500 messages in 41 Usenet groups then follows, with a view to establishing the following: how many messages are explicitly political; how many are in opposition to the current government; how many are pro‐government; whether they primarily serve as alternative sources of news; whether they are attempts to recruit people in the subject country and around the world into some sort of political action; and whether richer nations are more likely to have higher levels of discussion in their newsgroups than poorer ones. The findings conclude that newsgroups devoted to countries with lower levels of democratization have a much higher percentage of anti‐government messages than the newsgroups about nations that are more democratic.     

A Rationale and Method for Examining Reasons for Linkages Among Adolescent Risk Behaviors

A large volume of research has investigated interrelations among adolescent risk behaviors. Although several theoretical accounts have been proposed, researchers have not directly examined hypotheses for why risk behaviors are linked. In the present paper, a distinction is drawn between predictive factors that explain variance in risk behaviors and “linkage factors” which may provide an explanation for why risk behaviors are interrelated. The relevance of linkage factors to risk behavior research, theory, and practice is described. Further, a simple to use and easy to interpret analytic technique for exploring linkage-related issues is illustrated. Using this technique, hypotheses regarding the role of predictors in explaining linkages among risk behaviors can be tested directly. The proposed line of inquiry will provide valuable input for intervention efforts and theoretically relevant information concerning linkages among adolescent risk behaviors. Research Associate at the Brock Research Institute for Youth Studies at Brock University, Ontario, Canada. He received his M.A. in Clinical Psychology from the University of North Dakota. His major research interests are adolescent risk behavior involvement and youth activity involvement as a context for positive development. Professor in the Department of Child and Youth Studies at Brock University, Ontario, Canada. She received her Ph.D. in Developmental Psychology from the University of Waterloo. Her major research interests include adolescent risk taking and resilience, including academic underachievement and media/technology influences on lifestyle choices and learning. Assistant Professor in the Department of Child and Youth Studies at Brock University, Ontario, Canada. She received her Ph.D. in Developmental Psychology from Brock University. Her major research interests are adolescent risk-behavior involvement, particularly related to gambling, and risk and resilience.