Non-alcoholic fatty liver disease (NAFLD) is a serious metabolic condition affecting millions of people worldwide. A “Western-style diet” has been shown to induce pediatric NAFLD with the potential disruption of skeletal muscle composition and metabolism. To determine the in vivo effect of a “Western-style diet” on pediatric skeletal muscle fiber type and fuel utilization, 28 juvenile Iberian pigs were fed either a control diet (CON) or a high-fructose, high-fat diet (HFF), with or without probiotic supplementation, for 10 weeks. The HFF diets increased the total triacylglycerol content of muscle tissue but decreased intramyocellular lipid (IMCL) content and the number of type I (slow oxidative) muscle fibers. HFF diets induced autophagy as assessed by LC3I and LC3II, and inflammation, as assessed by IL-1α. No differences in body composition were observed, and there was no change in insulin sensitivity, but HFF diets increased several plasma acylcarnitines and decreased expression of lipid oxidation regulators PGC1α and CPT1, suggesting disruption of skeletal muscle metabolism. Our results show that an HFF diet fed to juvenile Iberian pigs produces a less oxidative skeletal muscle phenotype, similar to a detraining effect, and reduces the capacity to use lipid as fuel, even in the absence of insulin resistance and obesity.

In contrast to mammals and birds, effects of exercise on bone microstructure in reptiles have received scant attention. We investigated the effects of long‐term exercise on a treadmill or in a flume on limb bones of the American alligator. Juvenile alligators were run or swum to exhaustion every other day for 17 months, and received fluorescent dye injections to determine bone deposition rates. We found no significant differences in whole bone morphology and cortical bone deposition rates in the alligator humeral or femoral midshaft, regardless of exercise regimen. Similarly, we found no effects of either exercise regimen on trabecular number, thickness or density in the distal femur. In addition, bone mineral content was similar across exercise groups. Altogether, this suggests that long‐term exercise has no discernible effect on bone microstructure in alligators. These results stand in contrast to studies on endothermic vertebrates. The disparity could be due to metabolic differences between ectothermic and endothermic vertebrates. An alternative explanation is that alligator limb bones are subjected to insufficient strain levels or load cycles during short exercise bouts, which may account for lack of bone remodelling in response to exercise in alligators. Funded by the NSF IOB 04445680 to JWH.

Expertise in searching and evaluating scientific literature is a requisite skill of trained scientists and science students, yet information literacy instruction varies greatly among institutions and programs. To ensure that science students acquire information literacy skills, robust methods of assessment are needed. Here, we describe a novel tool for longitudinal, crossover assessment of literature-searching skills in science students and apply it to a cross-sectional assessment of literature-searching performance in 145 first-year and 43 senior biology majors. Subjects were given an open-ended prompt requiring them to find multiple sources of information addressing a particular scientific topic. A blinded scorer used a rubric to score the resources identified by the subjects and generate numerical scores for source quality, source relevance, and citation quality. Two versions of the assessment prompt were given to facilitate eventual longitudinal study of individual students in a crossover design. Seniors were significantly more likely to find relevant, peer-reviewed journal articles, provide appropriate citations, and provide correct answers to other questions about scientific literature. This assessment tool accommodates large numbers of students and can be modified easily for use in other disciplines or at other levels of education.

Prior studies, including Medler in 2019 ( Adv Physiol Educ 43: 69–75, 2019), have shown that the primary anesthetic used in fish and other aquatic vertebrates, MS-222, blocks nerve and muscle function and thus interferes with classroom neuromuscular physiology demonstrations in frogs. In this study, we show that eugenol anesthesia is practical and effective for classroom experiments, and we characterize the effect of eugenol on neuromuscular physiology over different anesthetic durations.