The human pathogen Vibrio vulnificus undergoes phase variation among colonial morphotypes, including a virulent opaque form which produces capsular polysaccharide (CPS) and a translucent phenotype that produces little or no CPS and is attenuated. Here, we found that a V. vulnificus mutant defective for RfaH antitermination control showed a diminished capacity to undergo phase variation and displayed significantly reduced distal gene expression within the Group I CPS operon. Moreover, the rfaH mutant produced negligible CPS and was highly sensitive to killing by normal human serum, results which indicate that RfaH is likely essential for virulence in this bacterium.

Suicide rates among military-connected populations have increased over the past 15 years. Meta-analytic studies indicate prediction of suicide outcomes is lacking. Machine-learning approaches have been promoted to enhance classification models for suicide-related outcomes. In the present study, we compared the performance of three primary machine-learning approaches (i.e., elastic net, random forests, stacked ensembles) and a traditional statistical approach, generalized linear modeling (i.e., logistic regression), to classify suicide thoughts and behaviors using data from the Military Suicide Research Consortium’s Common Data Elements (CDE; n = 5,977–6,058 across outcomes). Models were informed by (a) selected items from the CDE or (b) factor scores based on exploratory and confirmatory factor analyses on the selected CDE items. Results indicated similar classification performance across models and sets of features. In this study, we suggest the need for robust evidence before adopting more complex classification models and identify measures that are particularly relevant in classifying suicide-related outcomes.

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Objective While the lack of relation between performance- and inventory-based executive function (EF) measures is well documented, there remains ambiguity between self-report EFs and closely related constructs (e.g., impulsivity) assessed via the same method. The degree of convergence between purported EF measures with similar yet distinct constructs contain important theoretical implications for available EF assessment strategies and their construct validity. A newer measure of EF, the Behavior Regulation Inventory of Executive Functions—Adult (BRIEF-A), allows for more direct comparisons to self-reported measures of impulsivity, such as the commonly used Urgency, Planning, Perseverance, Sensation Seeking—Positive Urgency (UPPS-P) assessment. Method The present study used factor analysis and hierarchical regression to explore the associations between the BRIEF-A and UPPS-P, using alcohol and cannabis consumption across various outcomes (i.e., quantity-frequency and consequences) as an external criterion. Participants were 339 undergraduate students (Mage = 19.35; Female = 63%) from a large southwestern university. Results The BRIEF-A and UPPS-P demonstrated strong correlations at both higher- and lower order facets. While the BRIEF-A was a significant correlate to many substance use outcomes, these relations were generally weaker than those seen with the UPPS-P. Hierarchical regression suggested limited contributions of the BRIEF-A over and above the UPPS-P. Conclusions Overall, this study suggested substantial overlap between impulsigenic factors and EFs when measured by self-report, and limited utility of EF measures to account for unique variance with substance use outcomes in this sample.