Positive, complicated, distant, and negative: How different teacher-student relationship profiles relate to students' science motivation.

INTRODUCTION: Researchers note a consistent decline in adolescents' motivation and participation in science. It is important to examine factors vital to students' motivation in science, such as teacher-student relationships (TSRs). Limited research in science has examined TSRs from a multidimensional or person-centered perspective. The present investigation adopts Ang's tripartite relational framework to examine three dimensions of TSRs: socio-emotional support, instrumental help, and conflict. Such research is needed to better understand the diversity of relationships that exist within a science classroom and their impact on science motivation. METHODS: This study examined N = 2669 Australian high school students (66% girls; Mage = 15.11 years; SD = 0.69). Data were collected via online sampling in the final quarter of 2020. The data are cross-sectional. Latent profile analysis was used to (1) determine if distinct student profiles based on the three dimensions of TSRs existed and (2) the extent to which these profiles were associated with varying levels of science motivation: self-efficacy, intrinsic value, utility value, and cost. RESULTS: Four distinct profiles were identified: Positive, Complicated, Distant, and Negative. Students in the Negative TSR profile reported the lowest adaptive motivation and highest cost. The associations between profile membership and motivation were more varied for the Positive, Complicated, and Distant TSR profiles. CONCLUSIONS: Findings indicate that dichotomous perspectives (positive vs. negative) may be insufficient to describe the diversity of relationships within science classrooms. Results also suggest that concurrent attendance to all dimensions of TSRs is needed to improve relationships.

Microbiome disruption and recovery in the fish Gambusia affinis following exposure to broad-spectrum antibiotic.

Antibiotics are a relatively common disturbance to the normal microbiota of humans and agricultural animals, sometimes resulting in severe side effects such as antibiotic-associated enterocolitis. Gambusia affinis was used as a vertebrate model for effects of a broad-spectrum antibiotic, rifampicin, on the skin and gut mucosal microbiomes. The fish were exposed to the antibiotic in the water column for 1 week, and then monitored during recovery. As observed via culture, viable counts from the skin microbiome dropped strongly yet returned to pretreatment levels by 1.6 days and became >70% resistant. The gut microbiome counts dropped and took longer to recover (2.6 days), and became >90% drug resistant. The resistance persisted at ~20% of skin counts in the absence of antibiotic selection for 2 weeks. A community biochemical analysis measuring the presence/absence of 31 activities observed a 39% change in results after 3 days of antibiotic treatment. The antibiotic lowered the skin and gut microbiome community diversity and altered taxonomic composition, observed by 16S rRNA profiling. A 1-week recovery period did not return diversity or composition to pretreatment levels. The genus Myroides dominated both the microbiomes during the treatment, but was not stable and declined in abundance over time during recovery. Rifampicin selected for members of the family Comamonadaceae in the skin but not the gut microbiome. Consistent with other studies, this tractable animal model shows lasting effects on mucosal microbiomes following antibiotic exposure, including persistence of drug-resistant organisms in the community.