Nutritional Regulation of Growth Hormone-Stimulated Lipolysis

Growth hormone (GH) regulates several physiologic processes in vertebrates, including the promotion of growth, an anabolic process, and mobilization of stored lipid, a catabolic process. Here, we used rainbow trout (Oncorhynchus mykiss) as a model to examine the nutritional programming required for the disparate metabolic actions of GH, specifically lipolysis. Juvenile trout were exposed to fed and fasting regimens in vivo and subsequent hormone treatment in vitro. We used real-time quantitative-PCR to measure levels of mRNA expression of Hormone-sensitive lipase 1 (HSL1) and HSL2 in liver, muscle, and adipose tissue. We used Western blotting to investigate the signaling pathways affected by nutritional state and activated by GH (e.g., JAK-STAT, MAPK, PI3K-AKT, PKC-PLC). In vivo, fasting retarded growth and activated lipolysis through enhanced HSL mRNA expression and protein activation. Moreover, fasting resulted in phosphorylation of ERK and PKC but not Akt, JAK2, and STAT5 in adipose tissue, liver, and muscle. In vitro, GH stimulated glycerol release, HSL mRNA expression, and HSL phosphorylation in a time- and concentration- related manner but only in hepatocytes isolated from fasted and not fed fish. Moreover, these actions were dependent upon PKC-PLC and MAPK-ERK activation but not JAK-STAT or PI3K-Akt action. Nutritional state, insulin, and insulin-like growth factor I (IGF-I) pretreatments affect lipolytic responsiveness in hepatocyte. When in a fed state, with high levels of insulin and IGF, GH links to JAK-STAT pathways to promote growth. In a fasted state, with low levels of insulin and IGF, GH links to lipolysis through PKC and ERK activation. The findings of this dissertation indicate that nutritional status of an organism may mediate the pleiotropic actions of GH by linking it to unique intracellular signaling pathways. In the circumstances of fasting, GH stimulates lipolysis through PKC and ERK activation.National Science Foundation (NSF)ND EPSCoRNorth Dakota State University. Deptartment of Biological Science

Establishing Students’ Abilities to Reason with Relationships in the Context of Cellular Respiration

This study aims to establish the level at which University of Nebraska-Lincoln students reason with simple relationships in the context of cellular respiration at the levels of glycolysis, Krebs cycle, and electron transport chain. These processes are component processes of cellular respiration and each has multiple inputs and outputs. 633 student consented for this study, from which 18 student models were randomly selected, processed, and analyzed. Classroom observations were used to determine structures and relationships that were inputs and outputs to the three processes. In their models, students did not include different numbers of input or outputs when describing glycolysis, Krebs cycle and the electron transport On average, students had about one input and more than one output per process. The correctness was high for all three processes, however, relationships associated with Krebs cycle were significantly lower than relationships associated with ETC. Relationships associated with glycolysis were intermediate in quality. It was concluded that student\u27s still have a limited understanding of all processes, despite high correctness, because only one input and output for each process was included when three to four should be expected. Students must develop their system thinking skills to comprehend the smaller components at a high level, before they can consider the entire system. Current research suggests that computational modeling is one approach the University can implement as an activity to develop students\u27 system thinking skills

Changes in students’ mental models from computational modeling of gene regulatory networks

Background: Computational modeling is an increasingly common practice for disciplinary experts and therefore necessitates integration into science curricula. Computational models afford an opportunity for students to investigate the dynamics of biological systems, but there is significant gap in our knowledge of how these activities impact student knowledge of the structures, relationships, and dynamics of the system. We investigated how a computational modeling activity affected introductory biology students’ mental models of a prokaryotic gene regulatory system (lac operon) by analyzing conceptual models created before and after the activity. Results: Students’ pre-lesson conceptual models consisted of provided, system-general structures (e.g., activator, repressor) connected with predominantly incorrect relationships, representing an incomplete mental model of gene regulation. Students’ post-lesson conceptual models included more context-specific structures (e.g., cAMP, lac repressor) and increased in total number of structures and relationships. Student conceptual models also included higher quality relationships among structures, indicating they learned about these context-specific structures through integration with their expanding mental model rather than in isolation. Conclusions: Student mental models meshed structures in a manner indicative of knowledge accretion while they were productively re-constructing their understanding of gene regulation. Conceptual models can inform instructors about how students are relating system structures and whether students are developing more sophisticated models of system-general and system-specific dynamics

A Framework & Lesson to Engage Biology Students in Communicating Science with Nonexperts

Published as Wack, J., Jaeger, C., Yuan, S., & Bergan-Roller, H. E. (2021). A Framework & Lesson to Engage Biology Students in Communicating Science with Nonexperts. The American Biology Teacher, 83(1), 17-25. ©2021 by the Regents of the University of California/National Association of Biology Teachers. Copying and permissions notice: Authorization to copy this content beyond fair use (as specified in Sections 107 and 108 of the U. S. Copyright Law) for internal or personal use, or the internal or personal use of specific clients, is granted by the Regents of the University of California/on behalf of the National Association of Biology Teachers for libraries and other users, provided that they are registered with and pay the specified fee via Rightslink® or directly with the Copyright Clearance Center.Communicating science with non-experts (SciComm) is an important scientific practice. SciComm can inform decision making and public policies. Recently, seminal reports have indicated that SciComm is a practice in which students should engage. Unfortunately, students have few opportunities to engage in SciComm partially due to the absence of a framework that can help instructors facilitate such activities. We present a framework of the essential elements of effective SciComm that synthesizes previous work to describe the who, why, what, and how of effectively communicating science with non-experts. We applied the framework to a lesson for undergraduate biology students and assessed student outcomes. The lesson uses an introduction, assignment sheet, and worksheet to guide students through planning, producing, and describing their SciComm assignment. We assessed the outcomes of the lesson by quizzing students on their knowledge of SciComm and asking about their perceptions of SciComm and the lesson. Students performed well but focused some of their responses on what they were assigned in the lesson instead of what was best for effective SciComm. Moreover, students perceived the lesson positively. This work can be used by practitioners and researchers to understand how to engage students in the important scientific practice of SciComm

Establishing a Baseline of Science Communication Skills in an Undergraduate Environmental Science Course

Background Seminal reports, based on recommendations by educators, scientists, and in collaboration with students, have called for undergraduate curricula to engage students in some of the same practices as scientists—one of which is communicating science with a general, non-scientific audience (SciComm). Unfortunately, very little research has focused on helping students develop these skills. An important early step in creating effective and efficient curricula is understanding what baseline skills students have prior to instruction. Here, we used the Essential Elements for Effective Science Communication (EEES) framework to survey the SciComm skills of students in an environmental science course in which they had little SciComm training. Results Our analyses revealed that, despite not being given the framework, students included several of the 13 elements, especially those which were explicitly asked for in the assignment instructions. Students commonly targeted broad audiences composed of interested adults, aimed to increase the knowledge and awareness of their audience, and planned and executed remote projects using print on social media. Additionally, students demonstrated flexibility in their skills by slightly differing their choices depending on the context of the assignment, such as creating more engaging content than they had planned for. Conclusions The students exhibited several key baseline skills, even though they had minimal training on the best practices of SciComm; however, more support is required to help students become better communicators, and more work in different contexts may be beneficial to acquire additional perspectives on SciComm skills among a variety of science students. The few elements that were not well highlighted in the students’ projects may not have been as intuitive to novice communicators. Thus, we provide recommendations for how educators can help their undergraduate science students develop valuable, prescribed SciComm skills. Some of these recommendations include helping students determine the right audience for their communication project, providing opportunities for students to try multiple media types, determining the type of language that is appropriate for the audience, and encouraging students to aim for a mix of communication objectives. With this guidance, educators can better prepare their students to become a more open and communicative generation of scientists and citizens.This project was funded by the Department of Biological Sciences, College of Liberal Arts and Sciences, and the Division of Research and Innovative Partnerships at Northern Illinois University, as well as the Summer Internship Grant Program at Northwestern University. Funds were used to support the authors in their work on this project. The funders had no input on any aspect of this project

Challenging Endocrinology Students with a Critical Thinking Workbook

This is the accepted manuscript of an article published in Advances in Physiology Education. The version of record can be found here: https://doi.org/10.1152/advan.00101.2019A central goal of science education is to help students develop higher order thinking skills to enable them to face the challenges of life. Accordingly, science instructors are now urged to craft their classrooms such that they serve not only as spaces for disseminating information, but also an arena through which students are encouraged to think scientifically and develop critical thinking skills. This project aimed to develop a workbook that helps postsecondary students learn endocrinology and engages them in critical thinking. Each of the five chapters focus on a different topic rooted within core biological concepts relevant to endocrinology. Such topics were identified upon cross referencing seminal reports on science education. Tenants of Numrich’s Sequence of Critical Thinking Tasks were used to guide the development of chapter sections with the intent of engaging students in critical thinking over time by way of practice and scaffolded guidance. Chapter sections include modeling, event sequencing, clinical application, research and communication, and simulation, each of which target a different repertoire of skills presented in Numrich’s framework. Students’ learning, experiences, and behaviors were used to evaluate the workbook and inform the revision of the workbook into the publicly-available second edition

Tissue-Specific Orchestration of Gilthead Sea Bream Resilience to Hypoxia and High Stocking Density

Two different O-2 levels (normoxia: 75-85% O-2 saturation; moderate hypoxia: 42-43% O-2 saturation) and stocking densities (LD: 9.5, and HD: 19 kg/m(3)) were assessed on gilthead sea bream (Sparus aurata) in a 3-week feeding trial. Reduced O-2 availability had a negative impact on feed intake and growth rates, which was exacerbated by HD despite of the improvement in feed efficiency. Blood physiological hallmarks disclosed the enhancement in O-2-carrying capacity in fish maintained under moderate hypoxia. This feature was related to a hypo-metabolic state to cope with a chronic and widespread environmental O-2 reduction, which was accompanied by a differential regulation of circulating cortisol and growth hormone levels. Customized PCR-arrays were used for the simultaneous gene expression profiling of 34-44 selected stress and metabolic markers in liver, white skeletal muscle, heart, and blood cells. The number of differentially expressed genes ranged between 22 and 19 in liver, heart, and white skeletal muscle to 5 in total blood cells. Partial Least-Squares Discriminant Analysis (PLS-DA) explained [R2Y(cum)] and predicted [Q2Y(cum)] up to 95 and 65% of total variance, respectively. The first component (R2Y = 0.2889) gathered fish on the basis of O-2 availability, and liver and cardiac genes on the category of energy sensing and oxidative metabolism (cs, hif-1 alpha, pgc1 alpha, pgc1 beta, sirts 1-2-4-5-6-7), antioxidant defense and tissue repair (prdx5, sod2, mortalin, gpx4, gr, grp-170, and prdx3) and oxidative phosphorylation (nd2, nd5, and coxi) highly contributed to this separation. The second component (R2Y = 0.2927) differentiated normoxic fish at different stocking densities, and the white muscle clearly promoted this separation by a high over-representation of genes related to GH/IGF system (ghr-i, igfbp6b, igfbp5b, insr, igfbp3, and igf-i). The third component (R2Y = 0.2542) discriminated the effect of stocking density in fish exposed to moderate hypoxia by means of hepatic fatty acid desaturases (fads2, scd1a, and scd1b) and muscle markers of fatty acid oxidation (cpt1a). All these findings disclose the different contribution of analyzed tissues (liver >= heart > muscle > blood) and specific genes to the hypoxic- and crowding stress-mediated responses. This study will contribute to better explain and understand the different stress resilience of farmed fish across individuals and species

Nutritional Regulation of Growth Hormone-Stimulated Lipolysis

Growth hormone (GH) regulates several physiologic processes in vertebrates, including the promotion of growth, an anabolic process, and mobilization of stored lipid, a catabolic process. Here, we used rainbow trout (Oncorhynchus mykiss) as a model to examine the nutritional programming required for the disparate metabolic actions of GH, specifically lipolysis. Juvenile trout were exposed to fed and fasting regimens in vivo and subsequent hormone treatment in vitro. We used real-time quantitative-PCR to measure levels of mRNA expression of Hormone-sensitive lipase 1 (HSL1) and HSL2 in liver, muscle, and adipose tissue. We used Western blotting to investigate the signaling pathways affected by nutritional state and activated by GH (e.g., JAK-STAT, MAPK, PI3K-AKT, PKC-PLC). In vivo, fasting retarded growth and activated lipolysis through enhanced HSL mRNA expression and protein activation. Moreover, fasting resulted in phosphorylation of ERK and PKC but not Akt, JAK2, and STAT5 in adipose tissue, liver, and muscle. In vitro, GH stimulated glycerol release, HSL mRNA expression, and HSL phosphorylation in a time- and concentration- related manner but only in hepatocytes isolated from fasted and not fed fish. Moreover, these actions were dependent upon PKC-PLC and MAPK-ERK activation but not JAK-STAT or PI3K-Akt action. Nutritional state, insulin, and insulin-like growth factor I (IGF-I) pretreatments affect lipolytic responsiveness in hepatocyte. When in a fed state, with high levels of insulin and IGF, GH links to JAK-STAT pathways to promote growth. In a fasted state, with low levels of insulin and IGF, GH links to lipolysis through PKC and ERK activation. The findings of this dissertation indicate that nutritional status of an organism may mediate the pleiotropic actions of GH by linking it to unique intracellular signaling pathways. In the circumstances of fasting, GH stimulates lipolysis through PKC and ERK activation.National Science Foundation (NSF)ND EPSCoRNorth Dakota State University. Deptartment of Biological Science

Analysis of Questions from Undergraduate Introductory Biology Students

The types of questions that students ask can be indicative of their science knowledge. Students questions can reveal to instructors what students do or do not understand about the material, and what about the material they are interested in. We were interested in the types of questions students ask specifically in the context of an introductory, undergraduate biology class. Here, students were prompted to provide questions that they had about the material they were to study before lecture. Our research question was: what types of questions do students ask when preparing for class when given freedom to choose their resources? To answer this question, we used emergent thematic analysis to create a taxonomy of the types of questions students asked as a part of an assignment where students were asked how they prepared for that day’s lecture, and to provide a question that they had about the topic given open resources (i.e., allowed to refer to whatever resources they wanted, not just read a textbook). We found that students ask a variety of questions. Students most frequently asked questions about simple definitions and mechanisms. Students asked about malfunctions in biological systems least often. Understanding the types of questions students ask will serve as one piece that will help instructors guide their students on how to effectively prepare for class and understand biological concepts.B.A. (Bachelor of Arts

Research‐driven facilitation of systems thinking with computational models in life sciences education

Systems thinking, computational modeling, and simulating systems are examples of important skills stressed in life sciences education by Vision and Change. In response to these calls, we have designed a computational modeling and simulation‐driven intervention to supplement current instruction in the life sciences curriculum. As part of our pre‐intervention assessment we evaluated students on their systems thinking in the context of cellular respiration. For this assessment, we had students create conceptual models. We found that students with lecture instruction are able to recall more components associated with the cellular respiration process but are not better able to integrate these components into the system compared to students without lecture instruction. As a result, we have designed computational interventions to facilitate learning about complex biological processes. In these activities, we have students make and test predictions and apply simulation results to cellular mechanisms. We then assess student thinking to examine if the computational intervention improves systems thinking and modeling skills. Our preliminary data suggest that this intervention increases students’ mechanistic reasoning abilities. Currently, we are deploying computational activities and assessing students thinking on the topics of cellular respiration and gene regulation in all LIFE 120 laboratories. Finally, we are in the process of developing new computational activities to be used as learning tools for additional topics on complex biological system