ABSTRACT
Much of the research about STEM students' motivation measures the relationship between student motivation and academic outcomes, focusing on the student's mindset. This study takes a different approach, considering student motivation and instructional practices. Teaching practices and student motivation were analyzed simultaneously in undergraduate Biology classes using a self-determination theory-based survey and the Classroom Observation Protocol for Undergraduate STEM, and observation notes were collected to document instructor and student behaviors. Quantitative data was used to differentiate students' motivational levels and qualitative data was collected to describe how instructors use specific teaching practices. The results provide a lens into how students' intrinsic motivation varies alongside the instructional practices and interactions in these classes. We found a correlation between higher levels of student motivation in interactive lecture and student-centered teaching profiles. This study highlights how the same practice can be implemented by multiple instructors with varying student motivation scores, pointing out the importance of fidelity to evidence-based instructional practice methods. The results of this study are discussed in the context of published empirical studies examining evidence-based instructional practices that are conceptually supportive of autonomy, competence, and relatedness. Active learning practices observed in this study correlated to positive learning outcomes are discussed and may serve as a guide for instructors interested in implementing specific active learning practices. Recommendations for instructors and departments that are interested in flexible methods to monitor progress toward active learning practices in biology and other STEM disciplines by combining the COPUS and self-determination survey results are presented.
ABSTRACT
Sagebrush (Artemisia spp.) in North America is an abundant native plant species that is ecologically and evolutionarily adapted to have a diverse array of biologically active chemicals. Several of these chemicals, specifically polyphenols, have antioxidant activity that may act as biomarkers of biotic or abiotic stress. This study investigated the spatial variation of antioxidant capacity, as well as the relationship between a mammalian herbivore and antioxidant capacity in Wyoming big sagebrush (Artemisia tridentata wyomingensis). We quantified and compared total polyphenols and antioxidant capacity of leaf extracts from sagebrush plants from different spatial scales and at different levels of browsing by a specialist mammalian herbivore, the pygmy rabbit (Brachylagus idahoensis). We found that antioxidant capacity of sagebrush extracts was positively correlated with total polyphenol content. Antioxidant capacity varied spatially within and among plants. Antioxidant capacity in sagebrush was not related to either browsing intensity or duration of association with rabbits. We propose that the patterns of antioxidant capacity observed in sagebrush may be a result of spatial variation in abiotic stress experienced by sagebrush. Antioxidants could therefore provide a biomarker of environmental stress for sagebrush that could aid in management and conservation of this plant in the threatened sagebrush steppe.
ABSTRACT
This report presents the Gateway Scholars Program, an NSF-S-STEM supported program that recruited academically talented undergraduate students with demonstrated financial need. The objectives of our program included establishing a mentored cohort program, implementing enhanced risk-based advising, integrating evidence-based instructional practices in the curriculum, engaging students in co-curricular experiences, and generating new knowledge about the effect of activities on retention, student success, and degree attainment. Knowledge about broadening participation and effectiveness of evidence-based practices in STEM curricular and co-curricular activities and systems developed through this program have the potential to impact all STEM departments.
ABSTRACT
For herbivores, nutrient intake is limited by the relatively low nutritional quality of plants and high concentrations of potentially toxic defensive compounds (plant secondary metabolites, PSMs) produced by many plants. In response to phytochemical challenges, some herbivores selectively forage on plants with higher nutrient and lower PSM concentrations relative to other plants. Pygmy rabbits (Brachylagus idahoensis) are dietary specialists that feed on sagebrush (Artemisia spp.) and forage on specific plants more than others within a foraging patch. We predicted that the plants with evidence of heavy foraging (browsed plants) would be of higher dietary quality than plants that were not browsed (unbrowsed). We used model selection to determine which phytochemical variables best explained the difference between browsed and unbrowsed plants. Higher crude protein increased the odds that plants would be browsed by pygmy rabbits and the opposite was the case for certain PSMs. Additionally, because pygmy rabbits can occupy foraging patches (burrows) for consecutive years, their browsing may influence the nutritional and PSM constituents of plants at the burrows. In a post hoc analysis, we did not find a significant relationship between phytochemical concentrations, browse status and burrow occupancy length. We concluded that pygmy rabbits use nutritional and chemical cues while making foraging decisions.