Graduate teaching assistants (GTAs) are often the primary instructors for undergraduate biology laboratories and serve as research mentors in course-based undergraduate research experiences (CUREs). While several studies have explored undergraduate perceptions of CUREs, no previous study has qualitatively described GTAs’ perceptions about teaching CUREs, despite the essential instructional role GTAs play. The purpose of this phenomenological study was to describe and ascribe meaning to the perceptions that GTAs have regarding benefits and challenges with instructional experiences in introductory biology CUREs. We conducted semistructured interviews with 11 GTAs instructing an introductory biology CURE at a 4-year public university. We found that, while GTAs perceived professional benefits such as experience in research mentoring and postsecondary teaching, they also described challenges, including the time required to instruct a CURE, motivating students to take ownership, and a lack of expertise in mentoring undergraduates about a copepod-based CURE. Feelings of inadequacy in serving as a research mentor and high levels of critical thinking were also cited as perceived issues. We recommend that the greater responsibility and increased time commitment perceived by GTAs in the current study warrants reconsideration by lab coordinators and administrators as to what content and practices should be included in pedagogical training specifically designed for CURE GTAs and how departmental and institutional policies may need to be adapted to better implement CUREs.

In many ecology classrooms, examinations, written reports, and oral presentations are common assessment methods. However, translating original research projects or reviews of the literature into a culminating professional-style poster session is increasingly more common as a pedagogical tool

Field courses provide transformative learning experiences that support success and improve persistence for science, technology, engineering, and mathematics majors. But field courses have not increased proportionally with the number of students in the natural sciences. We conducted a scoping review to investigate the factors influencing undergraduate participation in and the outcomes from field courses in the United States. Our search yielded 61 articles, from which we classified the knowledge, affect, behavior, and skill-based outcomes resulting from field course participation. We found consistent reporting on course design but little reporting on demographics, which limits our understanding of who takes field courses. Cost was the most commonly reported barrier to student participation, and knowledge gains were the most commonly reported outcome. This scoping review underscores the need for more rigorous and evidence-based investigations of student outcomes in field courses. Understanding how field courses support or hinder student engagement is necessary to make them more accessible to all students.

Mammalian hibernators, such as golden-mantled ground squirrels (; GMGS), cease to feed while reducing metabolic rate and body temperature during winter months, surviving exclusively on endogenous fuels stored before hibernation. We hypothesized that mitochondria, the cellular sites of oxidative metabolism, undergo tissue-specific seasonal adjustments in carbohydrate and fatty acid utilization to facilitate or complement this remarkable phenotype. To address this, we performed high-resolution respirometry of mitochondria isolated from GMGS liver, heart, skeletal muscle, and brown adipose tissue (BAT) sampled during summer (active), fall (prehibernation), and winter (hibernation) seasons using multisubstrate titration protocols. Mitochondrial phospholipid composition was examined as a postulated intrinsic modulator of respiratory function across tissues and seasons. Respirometry revealed seasonal variations in mitochondrial oxidative phosphorylation capacity, substrate utilization, and coupling efficiency that reflected the distinct functions and metabolic demands of the tissues they support. A consistent finding across tissues was a greater influence of fatty acids (palmitoylcarnitine) on respiratory parameters during the prehibernation and hibernation seasons. In particular, fatty acids had a greater suppressive effect on pyruvate-supported oxidative phosphorylation in heart, muscle, and liver mitochondria and enhanced uncoupled respiration in BAT and muscle mitochondria in the colder seasons. Seasonal variations in the mitochondrial membrane composition reflected changes in the supply and utilization of polyunsaturated fatty acids but were generally mild and inconsistent with functional variations. In conclusion, mitochondria respond to seasonal variations in physical activity, temperature, and nutrient availability in a tissue-specific manner that complements circannual shifts in the bioenergetic and thermoregulatory demands of mammalian hibernators.

No abstract