PREPARING FOR A CAREER IN ACADEMIA: EXPERIENCE WITH RESEARCH AND TEACHING A Capstone Presented to the Faculty of the Graduate School of Cornell University in Partial Fulfillment of the Requirements for the Degree of Master of Professional Studies in Agriculture and Life Sciences Field of Animal Science by Noel E. Acor August 2024 © 2024 Noel E. Acor ABSTRACT My objectives for this capstone project were to gain more experience in research and teaching to prepare for a career in academia. The outcomes include 1) completion of a research project and draft manuscript, and 2) development and instruction of a college-level course. I studied the reproductive cycles of African giant pouched rats and showed that there is high variability in the cycle length among females, and that females can be categorized into three groups based on their cycles. Interestingly, progesterone was significantly different among groups. I also developed and taught a 7-week course in physiology called Extreme Animal Adaptations (ANSC4940). This course was unique because it focused on evaluating different pedagogies, with content being secondary. Each lecture utilized a different active learning exercise (e.g., jigsaw classroom) to teach material, and students reflect on their experiences. The outcomes achieved will undoubtedly prepare me for a PhD program and academic career. 4 BIOGRAPHY Noel grew up in Victor, New York and always showed a great love for animals. Her dream was to attend Cornell University to become a veterinarian. In 2019, Noel started her journey at Cornell University, majoring in Animal Science to continue her lifelong goals of becoming a veterinarian. During her time at Cornell, she dedicated countless hours with the Cornell Raptor Program, teaching her peers and the local communities on the biology, conservation, and management of birds of prey. Through this experience, Noel found a new passion for teaching and decided to change career paths. Thus, after she received her Bachelor of Science, she pursued a Master of Professional Studies degree at Cornell University to gain teaching experience at a collegiate level. The unique opportunity to teach Cornell undergraduate students about animal physiology further strengthened this passion for Noel, and she plans to continue down this path. It is her goal to receive a doctorate and become a professor to continue teaching and inspiring students about the wonders of science. 5 ACKNOWLEDGMENTS I would like to extend my deepest appreciation for the following individuals. I would not have been able to have this wonderful and unique experience without them. First and foremost, the sincerest thanks to Dr. Jeremy Allen for being the best advisor, mentor, and friend. Watching you teach has been my biggest inspiration, and I hope to be half as good as the professor that you are. Thank you for believing in me throughout my entire Cornell education journey; I would not be where I am without you. I will always hold the experiences, conversations, and memories we have close to my heart. I am so grateful for you. Thank you to Dr. Alex Ophir and Dr. Ehren Bentz in the Department of Psychology at Cornell University. Allowing me to work in your lab increased my interest in research and equipped me with necessary skills to succeed in the future. Lastly, a heartfelt thanks to the students who enrolled in my course. Thank you for your patience as I did something completely unfamiliar to me. Your consistent generosity and positivity made this experience so much better, and I truly felt comfortable to teach for all of you. I wish you all luck in your future endeavors! 6 TABLE OF CONTENTS VOLUME I: DIFFERENCES IN ESTROUS CYCLE LENGTH AND SERUM PROGESTERONE IN FEMALE AFRICAN GIAN POUCHED RATS 8 INTRODUCTION 10 MATERIALS AND METHODS 12 Animals 12 Experiments and Sample Collection 13 Restraint and Anesthesia 13 Vaginal Cytology 14 Measurement of External Genitalia 16 Measurement of Serum Progesterone 16 Statistics 17 RESULTS 18 Experiment 1: Vaginal cytological changes during the estrous cycle of pouched rats 18 Experiment 2: Hormonal and morphologic changes during the estrous cycle 19 DISCUSSION 27 CONCLUSION 30 VOLUME II: EVALUATION OF DIFFERENT ACTIVE LEARNING STRATEGIES IN AN UNDERGRADUATE ANIMAL SCIENCE COURSE 32 INTRODUCTION TO ANSC4940: EXTREME ANIMAL ADAPTATIONS 32 INTRODUCTION TO PEDAGOGY & ACTIVE LEARNING 33 DEVELOPING ANSC 4940: EXTREME ANIMAL ADAPTATIONS 35 Week 1: Introduction to the Course 36 Week 2: Phenomenon in Nature & Poll Everywhere 36 Week 3: Unique Desert Animals & Case Studies 37 Week 4: Unique Tundra, Taiga, and Forest Animals & Brain Dumps 37 Week 5: Unique Aquatic Animals & the Jigsaw Classroom 38 Week 6: Unique Grassland Animals & Concept Mapping 38 Week 7: Climate Change and Gallery Walk 39 Final Project and Assessment 40 STUDENT FEEDBACK 41 Classroom Polling 41 Case Studies 41 Brain Dumps 42 Jigsaw Classroom 42 Concept Mapping 43 Gallery Walk 43 7 CONCLUSION 44 WORKS CITED 46 8 VOLUME I: DIFFERENCES IN ESTROUS CYCLE LENGTH AND SERUM PROGESTERONE IN FEMALE AFRICAN GIAN POUCHED RATS ABSTRACT African giant pouched rats (pouched rats) are widely known for their keen olfactory system and ability to detect landmines. However, more recent studies showed that changes in vaginal patency of female pouched rats is truly unique among mammals (Freeman et al., 2023) and highlights the importance of understanding more basic physiological processes like the estrous cycle. The purpose of the current study was to better characterize the estrous cycle of female pouched rats in our captive breeding colony. Vaginal cytology samples were collected from eighteen females for 12-14 consecutive days to determine the length and stages of the cycle. Feces, blood, and morphometric data were also collected on a subset of these females (n=12) to determine changes in progesterone (P4), estradiol (E2), and vulva size throughout the estrous cycle. Analysis of vaginal cytology samples showed the length of the cycle is highly variable among females, but that females can be grouped into three different types of cycling patterns: 1) Normal cycling, 2) Abnormal cycling, and 3) Non-cycling. Females with Normal cycles had an estrous cycle of 4-5 days with predictable patterns of estrus. Abnormal cycles were longer than 12 days and/or were not predictable, and non-cycling females appeared to be in anestrus with low cell density and predominance of neutrophils in their vaginal cytology samples. Interestingly, baseline serum P4 was significantly higher (P < 0.05) in normal females compared to females who were not cycling or had abnormal cycles. We hypothesized that morphological changes in the external genitalia could be used as an external marker of stage of estrous cycle, which 9 would be beneficial for selection and timing of females for use in breeding pairs, but there was no significant association among anogenital distance (AGD) or vulva size and the four stages of the estrous cycle (estrus, proestrus, metestrus, and diestrus). There was no significant difference in anogenital distance (AGD) or vulva size among the stages of the estrous cycle, however, there was a correlation between serum progesterone levels with AGD and vulva size. Our results indicate that there may be a female-on-female reproductive suppression of female African giant pouched rats. 10 INTRODUCTION Understanding basic reproductive physiology has been integral to the development of reproductive technologies and to improving reproductive success and efficiency in agricultural species. Perhaps more importantly, expanding the breadth and depth of knowledge to include more diverse species with unique reproductive adaptations is essential for wildlife conservation efforts. Our lab uses a subspecies of the African giant pouched rats (Crictomys ansorgei) as models to study olfaction and mate choice, and more recently we showed that reproductive physiology of female pouched rats is particularly unique. Interestingly, vaginal patency, the perforation and opening of the vaginal canal that allows for mating, can change between patent (open) and non-patent (closed) throughout adult life (A. R. Freeman et al., 2023). This plasticity has not been observed in other mammals, where the vaginal canal becomes patent and immutable by the time a female is sexually mature (A. R. Freeman et al., 2023). The mechanisms regulating vaginal patency are still unclear, and even less is known about more basic reproductive processes like the estrous cycle. A fundamental understanding of the pouched rat estrous cycle is necessary to improve the efficiency and success of captive breeding programs, because females will only breed when they are in estrus (heat), and there is currently no easy way to determine if a female is sexually receptive. The estrous cycle is a regular, reproductive cycle in female mammals defined by behavioral estrus and sexual receptivity. The estrous cycle can be divided into four chronological stages: estrus, metestrus, diestrus, and proestrus. In laboratory rats, the estrous cycle is 4 or 5 days long with the pouched rat showing both 4- or 5-day cycles in different studies (Cora et al., 2015; Oke & Oke, 1999). Each stage has their own 11 hormonal and cytological profiles, making them unique from one another. Most notably, estrus is when females are sexually receptive and display sexually receptive behaviors, such as lordosis (Powers, 1970). Metestrus is the shortest stage and often goes undetected, thus it can sometimes be seen characterized as diestrus I, with diestrus being referred to as diestrus II (Antunes et al., 2016). Many hormones dominate the estrous cycle, including progesterone and estradiol. Progesterone (P4) peaks twice in the estrous cycle, once at the start of metestrus going into diestrus, and then once again during proestrus. The peak at the start of metestrus/diestrus is due to the production of progesterone from the corpus luteum, that is formed during these stages (Antunes et al., 2016; Marcondes et al., 2002). If fertilization does not occur, the corpora lutea degrades, causing a sharp decline in progesterone. However, in some species it peaks once again at the end of proestrus, in tandem with the pre-ovulatory luteinizing hormone (LH) surge (Antunes et al., 2016). Estradiol also peaks at the end of proestrus, triggering the pre-ovulatory surge of gonadotropins (i.e., LH) (Sanabria et al., 2019). Estradiol then maintains baseline values during estrus. These hormonal changes cause vaginal cells to take different morphology throughout the estrous cycle. Vaginal cells can be collected through vaginal lavage and analyzed, to be used as markers of the different stages in the estrous cycle. In pouched rats, hormonal profiles during the estrous cycle have not been studied. In addition, there is lack of evidence that shows if there are changes to the external genitalia (i.e., vulva width, vulva length, vaginal depth) throughout the pouched rat cycle that can be used as a non-invasive way to detect estrus. However, in other 12 rodent studies, individuals in proestrus and estrus have enlarged vulvae and vaginal openings (Ajayi & Akhigbe, 2020). Therefore, this study looks to 1) determine the length of the estrous cycle in African pouched rats, 2) describe the progesterone changes that occur throughout their cycles, and 3) identify any morphological changes throughout the cycle. We hypothesize that our colony will have 4- or 5-day estrous cycles, as previously found. In addition, we expect to see hormonal changes much like those in other rodent species. Lastly, we hypothesize that there will be morphological changes to detect easily detect estrus in the Southern giant pouched rat. MATERIALS AND METHODS Animals All experiments were approved by Cornell University’s Center for Animal Resources and Education (CARE) and in compliance with International Animal Care and Use (IACUC) regulations. Pouched rats were housed in individual cages (sized 24”x24”x16”) within larger, same-sex rooms. Males and females were housed separately, with no visual or physical contact, in rooms that had independent ventilation. Animals were fed a diet of kibble (ScottPharma Solutions LabDiet 5053). Water and food were available ad libitum. A 12:12 (light:dark) light cycle was used because this closely resembles light exposure in their natural habitat, and because preliminary data showed that photoperiod had no effect on reproductive cyclicity (Unpublished data). 13 Experiments and Sample Collection Two main experiments were developed to better understand the characteristics of the pouched rat estrous cycle. The aim of Experiment 1 was to determine the length, stages, and cytological changes that occur during the estrous cycle. The aim of Experiment 2 was to characterize hormonal and morphological changes that occur at different stages of the estrous cycle. Samples were collected from a total of eighteen females in a serious of three separate trials (n=6 females per trial). In experiment 1, vaginal cytology samples were collected every day for fourteen consecutive days. Blood, feces, and morphometric data were also collected on a subset of females (n=12) in Experiment 1 for use in Experiment 2. Restraint and Anesthesia Due to their large size (1-3 kg), collection of vaginal cytology and blood samples from pouched rats is much more difficult compared smaller laboratory rodents. We developed a method to restrain females for collecting vaginal cytology samples that involves placing females head-first into a fabric cone, and this method was used to collect samples in Trial 1. Females were anesthetized in Trials 2 and 3 so that blood, feces, and body measurements of the external genitalia could be taken. Animals were anesthetized with isoflurane USP for approximately 15 minutes. All animals had normal recovery from anesthesia. 14 Vaginal Cytology Vaginal cytology samples were collected by vaginal lavage using 100 uL of sterile PBS. The lavage was pipetted onto a slide, which was gently rotated to distribute the fluid. Slides were dried at room temperature and then submitted to the Clinical Pathology Department at Cornell University for staining with Wrights Giemsa. Types and proportions of cells were determined microscopically at 20x magnification to determine stage of estrous cycle. Four main cell types were identified in vaginal cytology samples: parabasal cells, intermediate nucleated cells, anucleate superficial cells, and neutrophils based on previous studies (Cora et al., 2015; Oke & Oke, 1999). Cell types are described below, and their proportions at different stages of the estrous cycle are summarized in Table 1. Parabasal Cells. Parabasal cells are small epithelial cells with a uniform, round to ovoid shape. The dark basophilic staining and low cytoplasm to nucleus ratio often obscures the nucleus. Intermediate Cells. Intermediate cells are round to ovoid and have large, round nuclei. These cells are larger than parabasal cells with an increased ratio of cytoplasm: nucleus makes the cytoplasm clearly visible. Large and small intermediate cells were grouped together for analyses. 15 Anucleate Superficial Cells (Keratinized). Superficial cells were classified based on a “cornflake” shape with angular edges, evidence of keratinization, and the presence (nucleated) or absence (anucleated) of a nucleus. Although proportions of nucleated and anucleated cells were determined separately, the two groups were combined for analyses. Neutrophils. Neutrophils are the smallest of the cells, are round, and have a lobular nucleus. Oftentimes, these cells may clump together. Table 1. Classification of the estrous cycle based on proportion of cell type. Proportions are defined as Absent/Rare (0); Few (+); Moderate (++); and Predominate/Many (+++) Stage of Estrous Parabasal Cells Intermediate Cells Superficial Cells Neutrophils Proestrus + / ++ ++ ++ + Estrus 0 0 / + +++ 0 / + Metestrus 0 / + 0 / + ++ / +++ + / ++ Diestrus ++ + + / ++ +++ Anestrus 0 / + ++ + / ++ / +++ +++ In brief, estrus was characterized by a predominance (~100%) of anucleated superficial cells, the absence of neutrophils, and the presence of bacteria. Metestrus was only observed in a few instances (n=4) and is relatively short. Compared to estrus, metestrus has more neutrophils, few to none parabasal cells, and many superficial cells. All cell types are present during diestrus. Proestrus has a dramatic decrease in neutrophils after diestrus and the number of intermediate and nucleated superficial cells 16 increases. Anestrus is a period of noncycling and have variable cell proportions. In our observations, there was consistently a high number of neutrophils each day and a high volume of mucous. Parabasal cells remained low and superficial cells varied from few to many. Measurement of External Genitalia The ability to determine if a female is in estrus or not by non-invasive means is of interest. We hypothesized that certain changes in the size or appearance of the external genitalia correlates with whether a female is in estrus or not. Calipers were used to measure anogenital distance (AGD), vulva width, and vulva length to determine if there is a relationship among hormones, stage of cycle, and/or external morphology. AGD was measured from the base of the urethral papillae to the center of the anus. Overall vulva size (mm2) was determined by multiplying vulva length by vulva width. A dental probe with demarcations (mm) was gently inserted into the vestibule and vagina to measure the depth and tightness of the vagina. Measurement of Serum Progesterone In Experiment 2, approximately 500 uL of blood was drawn daily for 12 or 14 days by tail venipuncture using a 23 g needle and 1 mL syringe, which was transferred into no-additive serum collection tubes and stored on ice. Blood samples were centrifuged for 15 min at 4,000 rpm and serum (~200-300 uL) were transferred to tubes for storage at -20C. Serum samples were submitted to the Cornell Endocrinology lab and measured for progesterone using the MP Diagnostics Progesterone RIA. The 17 sensitivity of the assay is 0.06 ng/mL, and the high standard is 80 ng/mL. Dilutions of samples were also run to verify parallelism. Only progesterone was measured because estradiol was undetectable by RIA (< 15 pg/ml) in a subset of test samples, and we were unable to validate other methods to measure estradiol in pouched rat serum. The high standard for the progesterone RIA was 80 ng/mL and dilutions showed good parallelism. For each female, steroid concentrations were averaged and any value that was two standard deviations away from the average were considered outliers (i.e., peaks) and removed. Remaining concentration values were averaged again, and these calculations continued until there were no values two standard deviations away from the average. This average was determined to be the baseline hormone concentrations for fecal and serum steroids. Statistics All analyses were conducted using JMP Pro 17 and significance was set at P < 0.05. Data that were not normal were log transformed. Rat ID was included as a random variable. ANOVA and linear correlation tests were run. Global analysis of the data was performed using a mixed model, with rat ID as a random variable. Data sets with small sample were analyzed by nonparametric tests (Kruskal-Wallis). Non-cycling females were excluded from the analyses of serum progesterone during different stages of the estrous cycle. 18 RESULTS Experiment 1: Vaginal cytological changes during the estrous cycle of pouched rats Vaginal lavage was collected from 18 females over the course of three trials. Data for each rat are summarized in Table 2. Length of the estrous cycle length was determined by the number of days between two consecutive estruses, with estrus being day 1. Surprisingly, there was high variability in cycle length among the females sampled. However, three major classes of females emerged upon closer analyses: 1) Normal Cycling, 2) Abnormal Cycling, and 3) Non-Cycling. Cycles were considered normal if they lasted 4 or 5 days, showed at least 2 estruses, and were repetitive and predictable. Seven females had normal cycles lasting 4 to 5 days. One of these females had a six-day cycle but was predictable throughout the study, thus she was considered to have a normal cycle. Females with abnormal cycles appeared to be cycling based on vaginal cytology samples with high cell density, but these cycles were unpredictable and/or longer than 12 days. In some cases, estrus was not observed, and females remained in a state of persistent diestrus; the cell density suggested they were in fact cycling. Another seven females remained in one stage throughout their entire cycle. Out of these seven, four females persisted through diestrus, two in proestrus, and one in estrus. Two of the females had extremely long cycles and often only switched between two stages. Anestrus is the term for the lack of an estrous cycle. Cytologically, anestrus differs from diestrus in that there is often presence of thick mucus and low cell density, of which neutrophils are the predominant cell type. wo females were determined to be in anestrus or non-cycling. 19 Table 2. Summary of the estrous cycles in Experiment 1 UNK indicates that length was undetermined for that category Experiment 2: Hormonal and morphologic changes during the estrous cycle Blood, feces, and morphometric data were collected on a subset of females (n=12) during trials 2 and 3 of Experiment 1. Data was collected daily at the same time as vaginal cytology collection for 12 or 14 consecutive days. Data for each rat are summarized in Table 3. 20 Table 3. Summary of baseline serum and external genitalia measurements in Concentrations of serum progesterone and corresponding stage of cycle for representative females from each category are shown in Figures 1-3. Unexpectedly, the females who had normal cycles (Figure 1 A-C) did not have the same patterns of serum progesterone. Peaks in P4 either happened during proestrus or estrus and not every female with a normal cycle had a significant peak in P4. In addition, some females only peaked once over the span of multiple cycles. Females with abnormal cycles typically did not have any peaks in serum P4 (Figure 2). However, female 15 had two peaks of progesterone, both during diestrus. Her serum P4 profile suggests a normal estrous cycle, but based on vaginal cytology, her cycle length was not consistent and could not be predicted. Individuals in anestrus did not have any peaks in serum P4 (Figure 3). Average serum progesterone for females with normal and abnormal cycles (n=16) was calculated for each stage of the estrous cycle. There were no significant differences (P>0.05) in average progesterone concentrations among different stages of the cycle. 21 Figure. 1. Stages of estrous cycle and associated serum progesterone concentrations in females with normal cycles. ‘*’ indicates a significant peak in progesterone from the baseline. Stage of estrous corresponding to each day is indicated by E (estrus), M (metestrus), D (diestrus), and P (proestrus). 22 Figure 2. Change of serum progesterone (ng/mL) over the course of normal estrous cycles. ‘*’ indicates a significant peak in progesterone from the baseline. Stage of estrous corresponding to each day is indicated by E (estrus), M (metestrus), D (diestrus), and P (proestrus) on the x-axis. 23 Figure 3. Change of serum progesterone (ng/mL) over the course of non-cycling females. Anestrus (A) was observed for each day of sample collection. Measurements of baseline levels of serum progesterone, vulva length, vulva width, and AGD are summarized in Table 3. Statistical analysis (P < 0.05) showed that there is a significant difference in baseline levels of serum P4 among the types of cycle (Fig. 5). A Kruskal-Wallis further showed that P4 baselines in normal cyclers are 24 statistically significant from abnormal cyclers and females who were not cycling. There was no statistical difference between Abnormal cycling and Non-cycling females. The average serum P4 levels were found for each female. It was determined from a Tukey’s test that Normal cycling females had a statistically significant difference in average P4 than Abnormal cycling and Non-cycling females (Figure 6). No difference was found in the average P4 serum levels between Abnormal cycling and Non-cycling. Serum progesterone was compared to anogenital distance to see if serum progesterone influences anogenital distance (Figure 7). Weak linear correlation was found (r = -0.51), however there is a statistically significant effect of serum progesterone on anogenital distance (P < 0.0001, R2 = 0.26). Serum P4 was also determined to have a statistically significant effect on vulva size (P < 0.0001, r = 0.38, R2 = 0.15) (Fig. 8). Figure 4. Average baseline serum progesterone (ng/mL) in female pouched rats with normal cycles (n=7), Abnormal cycles (n=7) and non-cycling females (n=2). Means with no common letters are significantly different (P<0.05). 25 Figure 5. Average serum progesterone (ng/mL) in the stages of the estrous cycle of the female pouched rats. No statistical difference was found among the average serum progesterone in the different cycles (P > 0.05). 26 Figure 6. Linear correlation between serum progesterone (ng/mL) and anogenital distance (mm). There was a weak correlation found between serum progesterone and anogenital distance (r = -0.51). Serum P4 had a statistical difference on anogenital distance (P < 0.001). 27 Figure 7. Linear correlation between serum progesterone (ng/mL) and vulva size (mm2) Vulva size was determined by multiplying vulva length (mm) by vulva width (mm). Weak correlation was found between serum progesterone and vulva size (r = 0.38) Serum P4 had a statistical difference on vulva size (P < 0.001). DISCUSSION Data from the current study show that there is high variability in the length and hormonal profiles of the estrous cycles of captive African giant pouched rats. Despite this variability, we found that females could be grouped into three major groups (Normal Cycling, Abnormal Cycling, and Non-Cycling) based on the characteristics of their 28 cycles (Table 2). Normal cycles were defined as being 4-5 days in length with estrus being repetitive and predictable, which agrees with previous studies of Oke et al who showed that wild-caught pouched rats had a cycle of 4-5 days (Oke & Oke, 1999). However, Oke et al. did not observe different cycling types. Differences in our results could be due to using different subspecies of the African giant pouched rat. Captive bred and wild-caught females may also have differences in their estrous cycles. Although P4 levels were not significantly different throughout the stages of estrous, there was a significant difference in baseline P4 between the cycling groups. and that baseline serum progesterone was significantly higher in females in these groups (Figure 4) who had normal cycles compared to those with abnormal or no cycles. Normal cyclers had significantly higher serum P4 baselines compared to abnormal cyclers and non-cyclers. To our knowledge, this has not been observed in African giant pouched rat, however, has been seen in the naked mole rat, a social rodent species. From vaginal cytology, it was determined that subordinate naked mole rats do not cycle normally through the estrous cycle (Westlin et al., 1994). In addition, multiple studies have found that subordinate naked mole rats have lower levels of progesterone than breeding females (Faulkes et al., 1990; Westlin et al., 1994). Interestingly, when non-cycling naked mole rats are separated from dominate females and placed with males, their progesterone levels increase, suggesting female on female reproductive suppression (Faulkes et al., 1990). Similar studies should be done with the African giant pouched rat to better understand if female on female reproductive suppression also exists in the species. 29 The lack of progesterone peaks during a normal estrous cycle was surprising. It was expected to see repeated progesterone peaks during diestrus and proestrus over the course of multiple estrous cycles. In our study, Female 15 was the only female to have repeated progesterone peaks during diestrus but was not considered a normal cycler due to her unpredictable and long estrous cycle. Not all our normal cyclers had peaks in progesterone, but those that did mainly peaked only once during proestrus. Other rat studies found that progesterone peaks during proestrus, but none indicated that peaks were inconsistent and unpredictable like we observed. (Butcher et al., 1974; Chuon et al., 2022; Sanabria et al., 2019; Smith et al., 1975). In addition, we saw peaks during estrus, which has not been observed in other rat species. There has been evidence to show that progesterone may be linked to inducing the LH surge right before ovulation in rat species and canids (Butcher et al., 1974; Concannon et al., 1977), which could explain why we saw high peaks on progesterone during estrus in the African pouched rat. It is possible that we detected these peaks right at the beginning of estrus when LH also peaks to induce ovulation. Studies should be done to track the hormonal profile of LH throughout the pouched rat estrous cycle to compare to progesterone levels. Our results indicate that serum progesterone levels may play a role in anogenital distance and vulva size. However, we were unable to find any difference in morphometric data between stage of estrous, which has been observed in other rodent species (Ajayi & Akhigbe, 2020; Long & Evans, 1922). This suggests that African giant pouched rats may not have observable changes of their external genitalia during estrus, 30 but more studies must be done to examine the relationship between external genitalia and the estrous cycle. To our knowledge, our lab is the only institution in the US that currently has a captive breeding colony of African giant pouched rats. However, establishing successful breeding pairs has proved difficult and time-consuming, as males and females require several weeks of acclimation before allowing to breed. The ability to easily detect estrus (and sexual receptivity) in females could significantly improve the efficiency of our breeding program. Anecdotally, it seems likely that female on female suppression also occurs among breeding pairs. In early attempts, two breeding pairs of pouched rats were housed in separate cages, but within the same room, and only one of the breeding pairs produced pups. This study further supports the idea that female on female reproductive suppression of progesterone may exist in lab colonies of the African pouched rat. CONCLUSION Our results support the idea that female African giant pouched rats may have a female-on-female reproductive suppression mechanism due to baseline differences in serum progesterone. This in dominant, reproductively active females and subordinate, reproductively inactive females. This mechanism has not been observed in the wild, suggesting a possible lab-specific phenomenon. In addition, serum progesterone levels are correlated with morphometric data such as anogenital distance and vulva size, but vulva size could not be a predictor for estrus based on visualization alone. Regardless, 31 this study improves our understanding of the African giant pouched rat in captivity to increase the efficiency of breeding programs. 32 VOLUME II: EVALUATION OF DIFFERENT ACTIVE LEARNING STRATEGIES IN AN UNDERGRADUATE ANIMAL SCIENCE COURSE INTRODUCTION TO ANSC4940: EXTREME ANIMAL ADAPTATIONS Extreme Animal Adaptations (ANSC 4940) was a 7-week, undergraduate course taught within the Department of Animal Science at Cornell University. It met once a week for 115 mins, with 30 enrolled students. The course examined the unique physiologies of animals adapted to live in extreme environments or conditions. Students were required to apply their knowledge of physiology and adaptive radiation in a final project where they created a novel organism and explained the physiology responsible for the individual’s adaptations to a particular alien environment. By the end of the 7- weeks, students were intended to have a deeper understanding and appreciation for the physiology of the animals covered and how they can overcome harsh biomes. Lecture material was by reinforced by reading and discussing scientific articles on the animals and physiology covered. Course topics included specialized thermoregulation, metabolism, behavior, respiration, and more. Active learning strategies were implemented for each week. After each activity, students were required to submit anonymous surveys to reflect on how beneficial the active learning activity was for their learning and engagement. At the end of the course, students were required to take a survey that asked them to assess how well they knew the material. After, they took a multiple-choice assessment designed to test their overall knowledge from the material. After receiving their scores, they had to re-reflect on their knowledge, allowing me to judge their overall performance in the course. Overall, the 33 goal of Volume II of this capstone was to anecdotally assess the effectiveness of active learning based on student responses and my experiences in the classroom. INTRODUCTION TO PEDAGOGY & ACTIVE LEARNING The term pedagogy originates from ancient Greek which translates to “the act of leading a child” (Shah, 2021). In ancient Greece, pedagogues were slaves that were in charge of teaching children life skills and how to be successful. Because of this, pedagogues were seen as more important than teachers. Today, pedagogy is now an approach to teaching, shaped by the educator’s beliefs and incorporating diverse learning styles to maximize student education (Shah, 2021). In university classrooms, there are a wide range of cultures and learning styles, making it difficult for instructors to ensure each student is actively engaged and successful. Understanding the different pedagogical approaches is essential for an instructor to maximize student success. Implementing the different learning styles and pedagogical approaches creates a cohesive, inclusive environment for students to excel in their learning. Furthermore, this review focuses on different styles of pedagogy, specifically approaches that use active learning, and how these teaching styles maximize student learning. Constructivism is the pedagogical approach that argues that learning is an active and interactive process for students, where students are at the forefront of their education rather than the teacher (Shah, 2021). This is also called active learning, which has been shown to significantly enhance student learning compared to a passive, lecture style classroom (S. Freeman et al., 2014). Research has shown that active learning practices increases student engagement and expert attitudes towards course content (Deslauriers et al., 2019). In fact, one study found that students are 1.5x more 34 likely to fail a STEM class when it is taught in a traditional lecture setting, compared to an active learning classroom (S. Freeman et al., 2014). With increasing evidence that active learning boosts students’ grades and knowledge, active learning practices should be utilized more in college settings. One type of constructivist teaching is Project-Based Learning (PBL). PBL is typically a way for students for students to produce something as a way to measure their knowledge on the course’s subject matter (Chen & Yang, 2019). This typically involves creating a presentation, poster, or something made with their hands. In one metanalysis of 12,500 students in 189 schools, researchers found that PBL significantly increased academic achievement in students as well as improved student attitude towards the subject matter (Chen & Yang, 2019). PBL has been proved to be a great way for students to apply the knowledge they have learned and create something that can measure their knowledge and success, which is why having a final project rather than a final exam is more beneficial for college students. In addition to increasing student understanding, an active learning classroom has been shown to increase student attitudes and feelings towards learning. One survey- based study found that students had higher satisfaction in an active learning classroom and felt more comfortable, accepted, and important in these classroom settings (Bell, 2022). Having a classroom environment that is welcoming to all cultures and backgrounds is very important to me, evidence showing that active learning creates comfortability with students furthers strengthens my desire to use these practices in my class. Specifically, ensuring everyone, regardless of education background, is set up for success. For underrepresented individuals, such as low-income students, first- 35 generation students, and racial minorities, college is a very polarizing environment. To mitigate this, instructors that provide a safe space using active learning can help these students flourish and set them up for success (Theobald et al., 2020). In STEM majors specifically, these underrepresented students often drop out or switch to non-STEM majors due to poor scores and an increasing achievement gap between them and overrepresented students (Theobald et al., 2020). However, the increase of active learning strategies in STEM college courses has been able to decrease the achievement gap by 45% (Theobald et al., 2020). Being able to decrease the achievement gap can allow for underrepresented students to feel more comfortable in their learning environment, which is arguably equally, or more important as higher grades. In conclusion, the use of active learning has been shown to increase academic achievement and inclusivity in a college classroom, which are very important to me as an instructor. This is why I have decided to use more active learning practices in my class. Based on these studies, I hope to also increases the knowledge and academic achievement for my students. In addition, I hope the environment I create is inclusive and welcoming for all, regardless of their cultural, educational, or socio-economic background. DEVELOPING ANSC 4940: EXTREME ANIMAL ADAPTATIONS Each class period was designed to start with a lecture followed with a 15-minute break and concluded with a different active learning activity to reinforce material. Active learning activities were chosen based on Cornell University’s Center for Teaching 36 Innovation (CTI). I met one-on-one with one of the CTI specialists and used their resources to design my course with effective active learning activities. To get feedback on the active learning strategies, students were required to submit a brief survey at the end of each class to reflect on respective activity. Table 4 summarizes the subject of each week and its associated active learning activity. Table 4. ANSC 4940 Lecture Schedule Date Lecture Topic; Important Due Dates 3/18/24 1 Introduction to the Course 3/25/24 2 Phenomenon in Nature & Poll Everywhere 4/1/24 NO CLASS NO CLASS – SPRING BREAK 4/8/24 3 Unique Desert Animals & Case Studies 4/15/24 4 Unique Tundra, Taiga, and Forest Animals & Brain Dumps 4/22/24 5 Unique Aquatic Animals & Jigsaw Classroom 4/29/24 6 Unique Grassland Animals & Concept Mapping 5/6/24 7 Climate Change & Gallery Walk Week 1: Introduction to the Course The first class was dedicated to introducing the course and the syllabus. During this course, students were given full transparency of why I am teaching the course, the importance of it, and the expectations in an active learning classroom. Week 2: Phenomenon in Nature & Poll Everywhere Week two discussed the physiology of phenomenon that are often seen in nature. Topics covered included: migration, hibernation/torpor, echolocation, and magnetoreception. After the lecture, a Poll Everywhere activity was done to review the material and examine how well the material was retained. The students were not graded 37 on accuracy and got full points for participation. Classroom polling is an effective and easy way to create a more dynamic classroom (Classroom Polling | Center for Teaching Innovation, n.d.). The Poll Everywhere platform was chosen over other types of platforms polling due to its familiarity with Cornell University students. Week 3: Unique Desert Animals & Case Studies Week three discussed the physiology that are seen in animals living in desert biomes. The lecture started off with discussing the characteristics of deserts and followed with talking about the following animals and their unique adaptations: kangaroo rat, one-humped camel, sand gazelle, and fennec fox. Four case study questions were assigned to the students via Canvas. The goal of these questions was to stimulate higher-ordered thinking and application of knowledge to novel problems. There were not necessarily right answers, rather it was a way for students to problem solve open-ended questions. Grades were based on effort and participation on the questions. Week 4: Unique Tundra, Taiga, and Forest Animals & Brain Dumps Week 4 was dedicated to tundra, taiga, forest biomes as well as the unique animals who inhabit them. Animals discussed were emperor penguins, arctic foxes, Alaskan wood frogs, stingless bees, and sloths. This week’s activity was a brain dump. Students were asked to take 5 minutes to write down everything they remember from lecture. A graphic organizer was provided to help organize their thoughts if they wished to use it. After this closed-book activity, they were allowed to work with others and go through their notes and add what they may have missed or got incorrect. The 38 assignment was turned in for feedback as needed to ensure every student got the correct information. Brain dumps are a retrieval strategy that is a stress-free alternative to quizzes. These activities allow students to self-reflect on their understanding of the material, without the added stress of hurting their grades, like a quiz would do (4sure, 2021). Week 5: Unique Aquatic Animals & the Jigsaw Classroom During week 4, students were broken up into groups and assigned a different primary scientific article that discussed the adaptations of one of the following species: blue-ringed octopus, lantern shark, mudskipper, notothenioid Antarctic fish, and Guiana dolphin. Following a brief lecture on aquatic biomes, students broke off into their groups and discussed the main findings of their assigned paper. Students then broke off into new groups, that consisted of one person from each original group. In these new groups, their task was to teach everyone on the species that they were assigned. This structure is called the jigsaw classroom, which is used as a tool for students to become teachers for their peers, rather than passively listening to the instructor (Aronson, 2002). At the end of the class period, students turned in a graphic organizer of everything they learned from their peers and feedback was provided if needed. Week 6: Unique Grassland Animals & Concept Mapping Students learned about four species of grassland animals during week 6: African elephants, African wild dogs, cheetahs, and Ruppell’s vultures. After the lecture, students created their own concept map. Examples were provided, but ultimately students had creative freedom on how they wanted to organize their thoughts. Concept 39 mapping is a great tool to visualize course material and make connections. They are used to retain information, reveal connections, and be used as a study aid, especially for visual learners (Concept Mapping – Learning Strategies Center, n.d.). Concept maps were turned in and feedback was provided. Week 7: Climate Change and Gallery Walk The last week of the course was dedicated to how climate change is changing the biomes that were discussed throughout the course. Students were assigned one of the biomes and had to work in groups to brainstorm ways they think climate change was affecting that biome and the species that inhabit it. The students were required to answer three prompts: how their biome is changing; current examples of animals/plants adapting to climate change in their environment; predict how species may change due to climate change. The objective of this was to apply their knowledge of the adaptations learned throughout the course and make educated decisions on how they think species will be changing to overcome climate change. To help with the brainstorming process, articles, videos, and scientific literature were provided, but students were still required to do their own research to help answer the prompts. Groups created some sort of visual representation to be viewed by the entire class. Groups rotated throughout the room to view and learn from other groups. Students were encouraged to add and react to each other’s ideas. This active learning strategy is called a gallery walk, which is yet another way for students to be at the forefront of their learning, rather than passive intake from an instructor. 40 Final Project and Assessment Project-Based Learning was another active learning strategy implemented in ANSC 4940. Grades were primarily based on attendance, participation, and a final project. For the final project, students were given a random, made-up environment and were asked to create a novel organism that is well adapted to that environment. Students applied their knowledge of the adaptations discussed in class to create their organism. Students were also required to write a short paper that explained the physiology associated with each adaptation. Lastly, they had to discuss how climate change may impact their hypothetical animal, and whether their organism would be well adapted to environmental changes. A multiple-choice assessment was given at the end of the course to help gauge how well the students retained the information. This assessment was not graded based on accuracy, rather it was only for participation to ease the stress on the students. Table 5 summarizes the overall grade breakdown for the course. Table 5. Grade Breakdown for ANSC 4940 Assessment Points Percent Final Grade Surveys 35 14% Attendance 30 12% Participation and Engagement 35 14% Climate Change Gallery Walk 50 20% Final Project 100 40% Total 250 100% 41 STUDENT FEEDBACK Surveys were conducted at the end of each class to better understand how students felt about the different active learning strategies. Each survey was anonymous and allowed students to be honest and provide feedback and constructive criticism to the instructor. The surveys asked if they believed the activity helped them reach the learning outcomes of the course and enhanced their learning. Below summarizes some main points from survey responses. Classroom Polling Students felt that classroom polling helped them reinforce the content covered in class. They liked that it was a great way to review and test their knowledge, without the stress of their grades being affected. However, some students believed that using it did not allow for more in-class discussions on the material. Additionally, students wished there was a way to go back and review the questions outside of class. Based on the results of the final multiple-choice assessment, most of the students believed they were able to learn the main ideas associated with the classroom polling activity. However, most do not believe they are able to provide physiological explanations for each main concept. Students felt like classroom polling was the least helpful for their learning. Case Studies The third lecture was asynchronous due Cornell University pausing instruction for the solar eclipse. Thus, students had to watch the recorded lecture and do the case 42 study activity at home. Students liked the case study questions because it had them think deeper, rather than only copying from the lecture slides. However, they wish it was done in class so they could work with others and hold discussions to the open-ended questions. This activity was designed to be in person but had to be changed last minute due to instruction being paused. Regardless, most students felt they still retained the main ideas from this lecture and the case study activity was one of the more helpful activities in the course. Brain Dumps Students felt like brain dumps were the most helpful for their learning compared to other active learning strategies. They felt like it is a great tool to easily recall information and visualize gaps in their knowledge. Many students already used this method to study for tests and quizzes and is a go to study strategy. Some students were surprised that they were able to retain so much information, which improved confidence in themselves. Some students wished it was collaborative or had longer to jot down their thoughts. Again, the majority of students felt like they were able to retain the main ideas from the lecture. Jigsaw Classroom Based on the final assessment, the jigsaw classroom was one of the least helpful activities for their learning, with many students feeling like they had limited knowledge of the material associated with this activity. However, students still enjoyed the collaborative nature of the activity and the ability to discuss content on a deeper level. 43 Some students found this activity more difficult due to the rigor of the scientific papers. Others felt it was more stressful compared to other activities because they had to ensure they understood the paper thoroughly for their peers to understand it as well. These opinions may not reflect the activity’s effectiveness, rather the scientific papers chosen may have been too dense for this activity. Additionally, more instructor engagement with the groups could have made this activity much more successful. Concept Mapping Concept mapping was another favorite amongst the students. They felt like it was a great way to visualize what they learned in a low-stake setting. Additionally, they really liked the creative freedom it gave them, and helped them to identify gaps in their knowledge. Working with others on this activity greatly improved their experience with concept mapping. Most students felt like they had intermediate or advanced knowledge of the material associated with concept mapping. Gallery Walk The gallery walk activity was another favorite among the students mainly for its collaborative nature. They enjoyed looking at what other groups came up with, which ultimately aided in their learning and expanding their own ideas. However, auditory learners got less out of the activity and wished they could speak in front of the class, rather than walking around and reading the ideas of others. 44 CONCLUSION Overall, most students enjoyed the active-learning classroom and would not prefer if the class was only lecture based. Brain dumps and concept mapping was the most rewarding for students. Additionally, students thought the final project was a fun and creative way to apply their knowledge and was a great alternative to a final exam. Students seem to really enjoy group work that is catered more towards learning material, rather than getting a high grade. Providing a low stake environment allowed the students to enjoy the group discussions more and get more out of the activities. As the instructor, I felt the active learning strategies were very rewarding and a way to keep me engaged as well. I was able to get to know some of my students better due to the collaborative nature of active learning. Based on my experience, I believe active learning can be a very successful tool for college classrooms. However, in order to be successful, the instructor needs to be thoroughly trained on this style of teaching to maximize student engagement. Additionally, active learning is only successful if the students have a positive attitude about group discussions and are willing to put in the effort. As an instructor, it is extremely important to provide a safe space for students to discuss their ideas and feel accepted in the classroom. Without it, students may be less likely to participate, making active learning more burdensome than beneficial. Each student has their own learning style, making it very difficult for an instructor to successfully cater to each student. However, I think incorporating lectures with different active learning strategies is a good way for instructors to allow each student to learn the way they prefer. I think the most important thing is to provide different ways of learning and assessments, so students can learn the way that is most beneficial to them. Having 45 a rigid classroom structure does not promote inclusivity, which may affect student morale, confidence, and learning. This teaching experience was something completely out of my comfort zone. Although I do not think I was perfect at teaching, all but one student felt like they accomplished the learning outcomes. Many students told me they felt comfortable in my classroom and was their favorite class of the semester. At the end of the day, my main personal goal was to create a safe space for students, and I believe I was able to accomplish this. This experience was very eye-opening to me and taught me that teaching is incredibly hard, but the ability to inspire students makes up for the stress of teaching. 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