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Humans evolved to attend to valence and group membership when learning about their environment. The political domain offers a unique opportunity to study the simultaneous influence of these two broad, domain-general features of human experience. We examined whether the pervasive tendency for negatively valenced frames to “stick” in the mind applies to both intergroup and intragroup political contexts. In a preregistered experiment, we tested the effects of negative-to-positive (vs. positive-to-negative) reframing on people’s candidate preferences, first in the absence of party cue information and then in two partisan contexts: an intergroup context (analogous to a U.S. general election between opposing political parties) and an intragroup context (analogous to a U.S. primary election between candidates of the same party). We observed a persistent negativity bias in reframing effects, even in the presence of party cues. The results pave the way for future research at the intersection of psychology and political science.

The gut microbiome of worms from composting facilities potentially harbors organisms that are beneficial to plant growth and development. In this experiment, we sought to examine the potential impacts of rhizosphere microbiomes derived from Eisenia fetida worm castings (i.e. vermicompost) on tomato (Solanum lycopersicum, L.) plant growth and physiology. Our experiment consisted of a greenhouse trial lasting 17 weeks total in which tomato plants were grown with one of three inoculant treatments: a microbial inoculant created from vermicompost (V), a microbial inoculant created from sterilized vermicompost (SV), and a no-compost control inoculant (C). We hypothesized that living microbiomes from the vermicompost inoculant treatment would enhance host plant growth and gene expression profiles compared to plants grown in sterile and control treatments. Our data showed that bacterial community composition was significantly altered in tomato rhizospheres, but fungal community composition was highly variable in each treatment. Plant phenotypes that were significantly enhanced in the vermicompost and sterile vermicompost treatments, compared to the control, included aboveground biomass and foliar δ15N nitrogen. RNA sequencing revealed distinct gene expression changes in the vermicompost treatment, including upregulation of nutrient transporter genes such as Solyc06g074995 (high affinity nitrate transporter), which exhibited a 250.2-fold increase in expression in the vermicompost treatment compared to both the sterile vermicompost and control treatments. The plant transcriptome data suggest that rhizosphere microbiomes derived from vermicompost can influence tomato gene expression and growth-related regulatory pathways, which highlights the value of RNA sequencing in uncovering molecular responses in plant microbiome studies. [ABSTRACT FROM AUTHOR]

The practice of using covariates in experimental designs has become controversial. Traditionally touted by statisticians as a useful method to soak up noise in a dependent variable and boost power, the practice recently has been recast in a negative light because of Type I error inflation. But in order to make informed decisions about research practices like this one, researchers need to know more about the actual size of the benefits and costs of these practices. In a series of simulations, we compared the Type I error rates and power of two analytic practices that researchers might use when confronted with an unanticipated, independent covariate. In the baseline practice, a researcher only analyzes the effect of the manipulation on the dependent variable; in the flexible-covariate practice, she analyzes both the effect of the manipulation on the dependent variable and the effect adjusting for the unanticipated covariate. We show that the flexible-covariate (vs. baseline) practice inflates Type I error by a small amount, and that it boosts power substantially under certain circumstances. The flexible-covariate practice tends to be most beneficial when the covariate is strongly correlated with the dependent variable in the population, and when the experimental design would have been only moderately powered (40%–60%) without including the covariate in the analysis. We offer concrete recommendations for when and how to use independent covariates in experimental designs, and contextualize our findings within the movement toward quantifying trade-offs in choosing among research practices and optimizing the choice of practice within a given research context.

On college campuses today, student services staff (administrators and support staff) and faculty members are not only interacting with students but also with their parents. College employee interactions with prospective students and their parents may be common during information sessions and open houses. However, outside of the recruitment season, less is known about the experiences of student affairs staff and faculty who interact with parents. Through semi-structured interviews, this study examined employees’ interactions with parents of students at four colleges of applied arts and technology in Ontario, Canada. Of the interviewees, nine faculty members and 11 student affairs staff (non-academic employees) described interacting with parents. The analysis of the interviews revealed several themes. These included college employees’ interactions with parents regarding students’ program choice and educational decision making, academic challenges, and support services. Professional practices that serve parents (and other supporters) could contribute to institutional goals, including post-secondary student persistence. This study’s research findings may inform student affairs practice and inspire new ways to support students’ college journeys in cooperation with parents and family members. [ABSTRACT FROM AUTHOR]