Metabolic Flexibility and Weight Status May Contribute to Inter-Individual Changes in Breastmilk Lipid Content in Response to an Acute Bout of Exercise: Preliminary Findings from a Pilot Study

International Journal of Exercise Science 13(2): 1756-1769, 2020. The purposes of this pilot study were to describe changes in breastmilk lipid content in response to an acute bout of moderate intensity exercise and to explore maternal metabolic health factors, including metabolic flexibility, which may impact this change. A cross-sectional, observational, pilot study design was performed in 14 women between 4 and 6 months postpartum. Whole body fasting lipid oxidation was assessed, a standardized high-fat breakfast was consumed, and lipid oxidation was again measured 120-minutes post-meal. Metabolic flexibility was determined by comparing the change in lipid oxidation before and after the meal. Women completed 30-minutes of moderate intensity treadmill walking 150-minutes post-meal. Breastmilk was expressed and analyzed for lipid content before and after exercise. Overall, there was no significant difference between pre- and post-exercise breastmilk lipid content (pre-exercise 59.4±36.1 g/L vs. post-exercise 52.5±20.7 g/L, p=0.26). However, five (36%) women had an increase in breastmilk lipid content in response to the exercise bout, compared to nine (64%) that had a decrease in breastmilk lipid content suggesting inter-individual variability. The change in breastmilk lipid content from pre- to post-exercise was positively correlated to metabolic flexibility (r=0.595, p=0.03). Additionally, post-exercise lipid content was positively correlated with body mass index (BMI), body composition, and postpartum weight retention. Preliminary findings from this pilot study suggest that metabolic flexibility and maternal weight status may help explain the inter-individual changes in breastmilk lipid content in response to an acute bout of moderate intensity exercise

Mixed Student Ideas about Mechanisms of Human Weight Loss

Recent calls for college biology education reform have identified “pathways and transformations of matter and energy” as a big idea in biology crucial for students to learn. Previous work has been conducted on how college students think about such matter-transforming processes; however, little research has investigated how students connect these ideas. Here, we probe student thinking about matter transformations in the familiar context of human weight loss. Our analysis of 1192 student constructed responses revealed three scientific (which we label “Normative”) and five less scientific (which we label “Developing”) ideas that students use to explain weight loss. Additionally, students combine these ideas in their responses, with an average number of 2.19 ± 1.07 ideas per response, and 74.4% of responses containing two or more ideas. These results highlight the extent to which students hold multiple (both correct and incorrect) ideas about complex biological processes. We described student responses as conforming to either Scientific, Mixed, or Developing descriptive models, which had an average of 1.9 ± 0.6, 3.1 ± 0.9, and 1.7 ± 0.8 ideas per response, respectively. Such heterogeneous student thinking is characteristic of difficulties in both conceptual change and early expertise development and will require careful instructional intervention for lasting learning gains

Controversy in Biology Classrooms—Citizen Science Approaches to Evolution and Applications to Climate Change Discussions

The biological sciences encompass topics considered controversial by the American public, such as evolution and climate change. We believe that the development of climate change education in the biology classroom is better informed by an understanding of the history of the teaching of evolution. A common goal for science educators should be to engender a greater respect for and appreciation of science among students while teaching specific content knowledge. Citizen science has emerged as a viable yet underdeveloped method for engaging students of all ages in key scientific issues that impact society through authentic data-driven scientific research. Where successful, citizen science may open avenues of communication and engagement with the scientific process that would otherwise be more difficult to achieve. Citizen science projects demonstrate versatility in education and the ability to test hypotheses by collecting large amounts of often publishable data. We find a great possibility for science education research in the incorporation of citizen science projects in curriculum, especially with respect to “hot topics” of socioscientific debate based on our review of the findings of other authors

Climate Change and Energy Technologies in Undergraduate Introductory Science Textbooks

<p>Global climate change and the implementation of energy technologies are among the most pressing issues facing society and the environment today. Related educational content spans the science disciplines. Through an analysis of introductory-level university textbooks from four major US publishers in Biology, Chemistry, and Physics, this study presents trends in terminology and content. As the defining terms, “global warming” and “climate change” are used nearly equally. However, the first location of a working definition for climate change appears earlier. Energy technologies, climate change, and related environmental issues are found, on average, on ≤4% of textbook pages, and variation is large among individual textbooks. Discipline-based trends exist, especially for the energy technologies presented. Addressed separately as a non-renewable, non-fossil fuel, nuclear energy is found on ≤1% of textbook pages and unfavorably represented. The discussion within these science disciplines has implications on introductory-level education, public perception of science, and informed citizenship.</p

Anode Biofilms of <i>Geoalkalibacter ferrihydriticus</i> Exhibit Electrochemical Signatures of Multiple Electron Transport Pathways

Thriving under alkaliphilic conditions, <i>Geoalkalibacter ferrihydriticus</i> (<i>Glk. ferrihydriticus</i>) provides new applications in treating alkaline waste streams as well as a possible new model organism for microbial electrochemistry. We investigated the electrochemical response of biofilms of the alkaliphilic anode-respiring bacterium (ARB) <i>Glk. ferrihydriticus</i> voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. We observed there to be at least four dominant electron transfer pathways, with their contribution to the overall current produced dependent on the set anode potential. These pathways appear to be manifested at midpoint potentials of approximately −0.14 V, −0.2 V, −0.24 V, and −0.27 V vs standard hydrogen electrode. The individual contributions of the pathways change upon equilibration from a set anode potential to another anode potential. Additionally, the contribution of each pathway to the overall current produced is reversible when the anode potential is changed back to the original set potential. The pathways involved in anode respiration in <i>Glk. ferrihydriticus</i> biofilms follow a similar, but more complicated, pattern as compared to those in the model ARB, <i>Geobacter sulfurreducens</i>. This greater diversity of electron transport pathways in <i>Glk. ferrihydriticus</i> could be related to its wider metabolic capability (e.g., higher pH and larger set of possible substrates, among others)