Tweet valence, volume of abuse, and observers’ dark tetrad personality factors influence victim-blaming and the perceived severity of Twitter cyberabuse

Previous research into Twitter cyberabuse has yielded several findings: victim-blaming (VB) was influenced by victims’ initial tweet-valence; perceived severity (PS) was influenced independently by tweet valence and abuse volume; VB and PS were predicted by observer narcissism and psychopathy. However, this previous research was limited by its narrow focus on celebrity victims, and lack of consideration of observer sadism. The current study investigated 125 observers’ VB and PS perceptions of lay-user cyberabuse, and influence of observers’ Dark Tetrad scores (psychopathy, narcissism, Machiavellianism, sadism). We manipulated initial-tweet valence (negative, neutral, positive) and received abuse volume (low, high). Our results indicated that VB was highest following negative initial tweets; VB was higher following high-volume abuse. PS did not differ across initial-tweet valences; PS was greater following a high abuse volume. Regression analyses revealed that observer sadism predicted VB across initial-tweet valences; psychopathy predicted PS when initial tweets were ‘emotive’ (negative, positive), whereas Machiavellianism predicted PS when they were neutral. Our results show that perceptions of lay-user abuse are influenced interactively by victim-generated content and received abuse volume. Our current results contrast with perceptions of celebrity-abuse, which is mostly determined by victim-generated content. Findings are contextualised within the Warranting Theory of impression formation

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Range-wide genetic baseline alewife

Genetic baseline for alewife. Provided in this file is the individual ID composed of the location code (indicated in Reid et al., 2018) and the individual sample number, followed by the single nucleotide polymorphisms (SNPs). These SNPs are characterized in Baetscher et al., (2017). It should be noted that this genetic baseline excludes the populations of Dresden Mills and Sewall pond as described in the materials and methods. For more information please contact John Carlos Garza [email protected] or Kerry Reid [email protected]

Range-wide genetic baseline Blueback herring

Genetic baseline for blueback herring. Provided in this file is the individual ID composed of the location code (indicated in Reid et al., 2018) and the individual sample number, followed by the single nucleotide polymorphisms (SNPs). These SNPs are characterized in Baetscher et al., (2017). It should be noted that this genetic baseline excludes the population of Dresden Mills as described in the materials and methods. For more information please contact John Carlos Garza [email protected] or Kerry Reid [email protected]