Two modes of evolution shape bacterial strain diversity in the gut for thousands of generations

How and at what pace bacteria evolve when colonizing healthy hosts remains unclear. Here, by monitoring evolution for more than six thousand generations in the mouse gut, we show that the successful colonization of an invader Escherichia coli depends on the diversity of the existing microbiota and the presence of a closely related strain. Following colonization, two modes of evolution were observed: one in which diversifying selection leads to long-term coexistence of ecotypes and a second in which directional selection propels selective sweeps. These modes can be quantitatively distinguished by the statistics of mutation trajectories. In our experiments, diversifying selection was marked by the emergence of metabolic mutations, and directional selection by acquisition of prophages, which bring their own benefits and costs. In both modes, we observed parallel evolution, with mutation accumulation rates comparable to those typically observed in vitro on similar time scales. Our results show that gut environments can rapidly generate diversifying selection and ecotype formation.

Benefits and Costs of Mixed-Species Aggregations in Harvestmen (Arachnida: Opiliones)

Many animals form aggregations with individuals of the same species (single-species aggregations, SSA). Less frequently, individuals may also aggregate with individuals of other species (mixed-species aggregations, MSA). Although the benefits and costs of SSA have been intensively studied, the same is not true for MSA. Here, we first review the cases of MSA in harvestmen, an arachnid order in which the records of MSA are more frequent than other arthropod orders. We then propose several benefits and costs of MSA in harvestmen, and contrast them with those of SSA. Second, using field-gathered data we describe gregariousness in seven species of Prionostemma harvestmen from Costa Rica. These species form MSA, but individuals are also found solitarily or in SSA. We tested one possible benefit and one possible cost of gregariousness in Prionostemma harvestmen. Regarding the benefit, we hypothesized that individuals missing legs would be more exposed to predation than eight-legged individuals and thus they should be found preferentially in aggregations, where they would be more protected from predators. Our data, however, do not support this hypothesis. Regarding the cost, we hypothesized that gregariousness increases the chances of parasitism. We found no support for this hypothesis either because both mite prevalence and infestation intensity did not differ between solitary or aggregated individuals. Additionally, the type of aggregation (SSA or MSA) was not associated with the benefit or the cost we explored. This lack of effect may be explained by the fluid membership of the aggregations, as we found high turnover over time in the number of individuals and species composition of the aggregations. In conclusion, we hope our review and empirical data stimulate further studies on MSA, which remains one of the most elusive forms of group living in animals.

Inferring Humor Styles Through Men’s Formidability

Men’s formidability is inferred multimodally through various facial and bodily features. Such inferences frequently provide downstream perceptions of various traits and motivational states that inform subsequent affiliative decisions. Within these inferences could be an implicit understanding of men’s preferred humor styles. Across four studies, this research considered perceptions of men’s proclivity to employ each of the four humor styles through different formidability cues: upper body strength (Study 1), body muscularity (Study 2), facial width-to-height ratio (Study 3), and neck musculature (Study 4). Results indicated a relatively consistent perception of formidable features being diagnostic of men’s interest in aggressive humor. Additional findings indicate certain formidability cues connote a disinterest in self-defeating and self-enhancing humor. Facial and bodily cues finally connoted affiliative humor in different capacities. We frame findings from an evolutionary perspective based on perceptions of the various benefits and costs of different formidability features.

Survey on Student-Centered Learning Assessment and Feedback Practices - Research Brief

The challenge of assessing student progress and using information gained through assessment to improve teaching and learning is formidable. It can be argued that in student-centered learning (SCL) environments that challenge is even greater than in traditional frontal instruction classrooms. To better understand the assessment and feedback-giving practices of teachers in SCL classrooms, we invited teachers from across the United States to share with us their classroom practices relating to assessment and feedback-giving, the types of feedback they give to students, and their beliefs about the benefits and costs associated with feedback-giving. The goal of this report is to share back our preliminary findings with the participating teachers.

The concept of environmental capital in business accounting and integrated reporting

Subject. This article considers the conceptual basis of environmental capital accounting as one of the elements of assessing the value of business in conjunction with the concept of sustainable development of the organization. Objectives. The article aims to argue for a need for methodological and methodical information support in the system of business accounting for environmental safety of domestic business and identify the objects of the green economy and monetarization in the business accounting of the benefits and costs of creating and maintaining the organization’s ecosystem. Results. The article explains the need for the formation of various business accounting models in the system of the organization’s business model. Conclusions. Based on the study, the article concludes that it is necessary to reform the current system of accounting for environmental safety costs transforming it into business accounting of environmental capital.

The paradoxical consequences of leader feedback seeking for subordinates: a theoretical framework

Purpose Scholars in the feedback seeking domain have predominantly focused on subordinate feedback seeking. The authors still know very little about feedback seeking when the leader is the “seeker” and subordinates are the “targets” of such seeking. This paper aims to develop a theoretical framework that explores the potential benefits and costs of leader feedback seeking, specifically, leader feedback inquiry for subordinates. Design/methodology/approach The authors draw upon the transactional theory of stress to propose a framework in which leader feedback inquiry influences two subordinate behaviors (in-role and proactive skill development behaviors) via appraisal processes (challenge and threat appraisals). With insights from regulatory focus theory, the authors propose that individual characteristics, namely, the regulatory focus of subordinates (promotion and prevention focus), determine the appraisals of leader feedback inquiry, subsequently influencing subordinate behavioral outcomes. Findings The authors contend that leader feedback inquiry can be appraised as a challenge which then produces beneficial subordinate behaviors (i.e. higher in-role and proactive skill development behaviors). However, leader feedback inquiry can also be appraised as a threat which then elicits detrimental subordinate behaviors (i.e. lower in-role and proactive skill development behaviors). The authors then argue that subordinates with a high promotion focus appraise leader feedback inquiry as challenging, thereby enabling beneficial behaviors. Subordinates with a high prevention focus, by contrast, appraise leader feedback inquiry as threatening, thereby prompting detrimental behaviors. Originality/value The authors shed light on the benefits and costs of leader feedback seeking for subordinates. The resulting framework underlines the importance of including individual characteristics and cognitive appraisal processes in research investigating the effects of leader feedback inquiry on subordinate outcomes.

Where’S the “Everyday Black Woman”? an Intersectional Qualitative Analysis of Black Women’S Decision-Making Regarding HIV Pre-Exposure Prophylaxis (PrEP) in Mississippi

Background Black cisgender women in the U.S. South bear a disproportionate burden of HIV compared to cisgender women in other racial and ethnic groups and in any other part of the US. Critical to decreasing new HIV infections is the improved delivery of pre-exposure prophylaxis (PrEP) for Black cisgender women as it remains underutilized in 2021. Informed by intersectionality, the study sought to characterize the sociostructural influences on Black cisgender women’s deliberations about PrEP within the context of interlocking systems of oppression including racism, sexism, and classism. Methods Six focus groups were conducted with 37 Black women residing in Jackson, Mississippi. This sample was purposively recruited to include Black cisgender women who were eligible for PrEP but had never received a PrEP prescription. Results Six themes were identified as obstacles during PrEP deliberation among Black women: 1) limited PrEP awareness, 2) low perceived HIV risk, 3) concerns about side effects, 4) concerns about costs, 5) limited marketing, and 6) distrust in the healthcare system. Three themes were identified as facilitators during PrEP deliberations: 1) women’s empowerment and advocacy, 2) need for increased PrEP-specific education, and 3) the positive influence of PrEP-engaged women’s testimonials. Black women shared a limited awareness of PrEP exacerbated by the lack of Black women-specific marketing. Opportunities to support Black women-specific social marketing could increase awareness and knowledge regarding PrEP’s benefits and costs. Black women also shared their concerns about discrimination in healthcare and distrust, but they felt that these barriers may be addressed by patient testimonials from PrEP-engaged Black women, empowerment strategies, and directly addressing provider biases. Conclusions An effective response to PrEP implementation among Black women in the South requires developing programs to center the needs of Black women and carry out active strategies that prioritize peer advocacy while reinforcing positive and mitigating negative influences from broader social and historical contexts.