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2020 Abstracts

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The Influence of Staphylococcus Aureus Biofilm-associated Gene Mutations on Biofilm Composition

December 30, 0020 12:00 AM
Berges, Bradford; Wienclaw, Trevor; Ball, Ashley; Richmond, Bradley (Brigham Young University)
Faculty Advisor: Berges, Bradford (Life Sciences, Microbiology and Molecular Biology)

Staphylococcus Aureus (SA) biofilms are serious impediments to immune defenses and antibiotics, making them a major factor in SA infection. Such infections can be highly lethal even using current treatments, representing a major challenge to the healthcare industry. Previous genetic screenings of SA have revealed several genes that may be associated with biofilm formation. While the roles of many of these genes have been studied, little research has been done on how mutations of these genes impact biofilm composition. As several therapeutic options for treating mature SA biofilms require understanding of biofilm composition, a better understanding of how genes influence that composition is critical to improving current treatments and developing new ones.
In this project, we will study the biofilm phenotypes of SA with mutations in common biofilm-associated genes. By comparing the biofilm mass and composition of the wild-type (wt) Je2 strain to strains containing mutated biofilm-associated genes, we hope to uncover the impact that each mutation has on the composition of the biofilm matrix. We will utilize crystal violet assays as well as extracellular DNA and protein quantifying procedures to determine biofilm composition, after which meaningful comparisons can be made between mutant biofilms and wt biofilms.
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Deep learning for image segmentation

December 30, 0020 12:00 AM
Jenkins, Abigail; Baugh, Makinnon; Frandsen, Paul; White, Alexander; Dikow, Rebecca (Brigham Young University)
Faculty Advisor: Frandsen, Paul (Life Sciences, Plant and Wildlife Sciences)

Historically, physical plant specimens have been preserved and mounted on paper sheets and stored in plant collections, or herbaria. Herbarium collections are used for a wide variety of research purposes, including plant taxonomy, ecology, and evolutionary biology. The process of digitizing the herbarium sheets is simple and involves taking high resolution photos of each sheet and recording the corresponding metadata and attributes of the particular sample. Digitized herbarium sheets can be useful for a variety of purposes, and, by making images freely available online, they become immediately accessible to the scientific community, facilitating remote analysis. In addition, in a digital format, the images become computable and usable for purposes such as training deep learning models for classification or analysis of morphology.

While the process of digitizing is simple, herbarium sheets contain other features not directly representative of the plant, such as annotations, labels, museum stamps, color palettes, and rulers. There are additional inconsistencies in the herbarium sheets that are introduced through staining, record keeping, and natural degradation. Taken together, this information can contribute a substantial amount of noise if one is to use the image for downstream research analysis concerning the pattern, shape, or color of the specimen. We have developed a pipeline to filter this extraneous information, using image segmentation (whereby the specimen material is partitioned from the background) and deep learning.

We present this pipeline for generating training data for image segmentation tasks along with a novel dataset of highly resolved image masks segmenting plant material from background noise. We used this dataset to train a neural network to segment plant material in herbarium sheets more generally, and our method is applicable to other museum data sources where masking may be useful for quantitative analysis of patterns and shapes.
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Development of a New Molecular Predictor for Risk of Melanoma Brain Metastases

December 30, 0020 12:00 AM
Stehn, Christopher; Colman, Howard; Boucher, Kenneth; Grossman, Allie H; Holmen, Sheri L (University of Utah)
Faculty Advisor: Holmen, Sheri (University of Utah, Surgery)

Despite therapeutic advances in the treatment of melanoma, development of brain metastases continues to be a major cause of treatment failure. Prognosis for patients with brain metastases is exceedingly poor, therefore the development of sensitive and specific biomarkers to predict which melanoma patients are at highest risk for disease progression are needed. To accomplish this goal, we developed a novel combined molecular/clinical/pathologic predictor of brain metastasis risk. We first analyzed multiple gene expression datasets including The Cancer Genome Atlas (TCGA; n = 437) and an independent series from the European Genome-Phenome Archive (n = 183) and identified a list of 60 consensus genes that is robustly predictive of development of melanoma brain metastases (p < 0.05; FDR 5%). Next, we performed a similar analysis of association of miRNAs and melanoma brain metastasis risk which identified a set of miRNAs with significant predictive power. An optimized combined set of 15 mRNA and miRNA markers was a better predictor of brain metastasis risk than either mRNA or miRNA list alone when applied to the TCGA data set. The combined predictor was most sensitive in separating patients with no metastases from those with either brain metastases or systemic metastases. Current efforts are focused on optimizing miRNA and mRNA separation of patients specifically with brain metastases from those with other metastases using a machine learning linear classifier, and with integrating the expression classifier with other clinical and pathologic predictive factors including: age, stage, thickness, location, histology, ulceration, and gender. The sensitivity and specificity of the resulting clinical/molecular predictor will be validated in an independent retrospective patient dataset, and subsequently implemented in a prospective brain metastasis screening trial to determine real-world utility of this approach in preparation for prospective brain metastasis adjuvant/chemoprevention trials utilizing both immunotherapy and targeted therapy approaches.
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Effect of Mercury Chloride and Methyl Mercury

December 30, 0020 12:00 AM
Villanueva,Xitlalli; Berthelemy Nicole (Weber State University)
Faculty Advisor: Berthelemy, Nicole (Weber State University, Zoology)

Introduction: Mercury, originating from mining and industrial activity, has been accumulating in the Great Salt Lake water and has contaminated its food web. Some of the mercury chloride (HgCl) is transformed by benthic bacteria to the more toxic monomethyl mercury (MeHg). While the effect of HgCl on the brine shrimp Artemia franciscana has been described, little is known about the effects of MeHG on this shrimp, except that it is more toxic. We correlated the tissue mercury concentrations to the amount of mercury present in the sea-water (SW). We also tested the ability of the shrimp to depurate mercury accumulated in the tissues.
Results: - Adult Artemia survived at least one week when exposed to concentrations ranging from 10-9 to 10-5g/L HgCl or MeHg. Shrimp exposed to 10-4g/L HgCl or MeHg died within two days.
Fertility was influenced by mercury exposure. The number of offspring per brood produced by females exposed to 10-6g/L or less HgCl was around 150, significantly higher than the average 80 offspring per brood produced by females exposed to 10-6g/L MeHg. When exposed to 10-5g/l HgCl and MeHg, the females brood size was 47 and 24, respectively.
- Artemia is able to maintain low level of tissue mercury, up to exposure to 10-6g/L HgCl and 10-7 g/L for MeHg. Exposure to higher mercury concentrations leads to much higher mercury levels, about 35 ppm HgCl for SW reaching 10-5g/L and 300 ppm with exposure to 10-4 MeHg.
Discussion: While both HgCl and MeHg are lethal to the shrimp, after a few days exposure, at concentration higher than 10-6 g/L, MeHg has a stronger effect on fertility, with brood size near half the size. Also, MeHg, the organic form of mercury, is accumulated in much higher level than the inorganic form. The organic form has a better ability to cross cell membranes. Since the mercury levels in the Great Salt Lake reach 55 ng/L (= 0.055 10-6g/L) and 30 ng/L (0.03 10-6 g/L) for HgCl and MeHG, respectively, the brine shrimp population is likely not affected by this pollutant.
Conclusion: Mercury has a strong effect on Artemia metabolism. We will study, next, the shrimp response to the oxidative stress induced by the mercury exposure.
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Effects of Exercise on Subjective Feelings of Vitality: A Randomized Crossover Study

December 30, 0020 12:00 AM
Stevens, Andrew; Hicks, Joseph; Savage, Ryland; Bailey, Bruce (Brigham Young University)
Faculty Advisor: Bailey, Bruce (Life Sciences, Exercise Science)

Purpose: This study examined the effect that differing exercise intensities have on subjective ratings of vitality both immediately following the condition and after 60 minutes of intense cognitive testing.
Methods: These findings come as a secondary analysis of a larger randomized crossover study that examined the effects of differing exercise intensities on cognitive performance. We recruited 228 men and women in roughly equal numbers to participate in the study. Each participant reported to the study lab four times one week apart. During the first day the participants ran a VO2 max test to establish pacing and baseline values. During the next three visits the participant completed a subjective vitality questionnaire before exercise, after 40 minutes of exercise or watching a video, and after 60 minutes of cognitive testing. The exercise conditions of vigorous (70% VO2 Max), moderate (35% VO2 Max) and sedentary activity (watching a video) were randomly assigned each week.
Results: The vitality rating before exercise was not significantly different between the three conditions with a mean rating of 19.9 ± 8.6 cm. After the sedentary condition, subjective ratings of vitality decreased from 19.9 cm to 12.5 cm after the condition and increased to 15.0 cm after the cognitive testing, remaining below pre-exercise values. After the moderate exercise condition, vitality did not change significantly after exercise (20.2 cm to 21.0 cm) but was lower following the cognitive tasks (15.9 cm). Vitality was slightly elevated following the vigorous exercise condition (19.8 cm to 21.3 cm) but went down after the cognitive tasks (17.1 cm). Vitality ratings did not differ significantly between exercise conditions at any time. The sedentary condition was lower than both exercise conditions after the 40-min intervention (p<0.001) and was lower than the vigorous exercise condition after the cognitive tasks (p<0.001).
Conclusion: Sedentary tasks may reduce subjective feelings of energy and vitality and this subjective evaluation remains suppressed after a period of cognitive exertion. Feelings of vitality and energy remain similar before and after exercise (vigorous or moderate) but then reduce after cognitive exertion. Vigorous exercise may be slightly beneficial for subjective feeling of vitality after exercise and following extended cognitive exertion.
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Ecology of Male Mating in Alfaro cultratus: Is morphology a response to the environment?

December 30, 0020 12:00 AM
Mueller, Kaeli; Kaitlyn, Golden; Johnson, J.B. (Brigham Young University)
Faculty Advisor: Johnson, Jerry (Brigham Young University, College of Life Sciences);

Human-induced changes to the environment are causing declines in many of the world's species. Studying model organisms, such as Poeciilidae fishes, can provide crucial information about a variety of other species (Johnson & Bagley, 2011). Alfaro, a monophyletic genus within the family Poeciilidae (Bagley & Johnson, 2014), has the potential to become an exemplary model species. There is currently much scientific knowledge about the two distinct reproductive tactics of Poeciliid males. However, studies about the presence of this trait are lacking for Alfaro. Therefore, I propose adding to the current knowledge about Alfaro cultratus by researching the presence of two distinct sets of traits that accompany different male reproductive tactics. The hypothesis is that male Alfaro will show similar physical characteristics to other Poeciliids, but that these traits will not differ across varying habitats. Measurements of deceased Alfaro specimens will be analyzed to identify differences in physical traits. This will be followed by a live experiment, in which the male size differential is expected to mirror that of the deceased specimens. This research will produce novel information about Alfaro cultratus because its life history strategies have yet to be described. Many intriguing evolution questions could follow.

References:

Bagley, J. C., & Johnson, J. B. (2014). Testing for shared biogeographic history in the lower Central American freshwater fish assemblage using comparative phylogeography: Concerted, independent, or multiple evolutionary responses? Ecology and Evolution, 4(9), 1686—1705.

Johnson, J. B., & Bagley, J. C. (2011). Ecology and Evolution of Poeciliid Fishes, Chapter 4, Ecological drivers of life-history divergence.
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Comparative anatomy and connectivity of the Aii amacrine cell in mouse and rabbit retina

December 30, 0020 12:00 AM
Sigulinsky, Crystal; Anderson, James; Emrich, Daniel; Rapp, Christopher; Dahal, Jeebika; Pfeiffer, Rebecca; Rapp, Kevin; Yang, Jia-Hui; Watt, Carl; Marc, Robert; Jones, Bryan (University of Utah)
Faculty Advisor: Jones, Bryan (University of Utah, Ophthalmology/Visual Sciences)

Purpose: Mouse retina differs structurally from rabbit retina, as it is thicker and vascular, while rabbit retina is thinner and avascular. The implications of these differences on neuronal morphology and connectivity is unclear. We compare the morphology and connectivity of the Aii amacrine cell (AC) at ultrastructural precision in connectomes of mouse (RC2) and rabbit (RC1) retina.

Methods: RC1 and RC2 are 0.25 mm diameter volumes built by automated transmission electron microscopy at 2 nm/pixel resolution. RC1 is from a 13 month old, female Dutch Belted rabbit. RC2 is from a 5 month old female C57BL/6J mouse. The Viking application was used to annotate Aii ACs.

Results: Mouse Aii ACs are elongated with a prominent neck region. Lobular appendages in both species extend from the soma, neck and proximal arboreal dendrites in the OFF sublamina, forming reciprocal synapses with OFF cone bipolar cells (BCs). In rabbits, multiple arboreal dendrites emerge from the base of the neck, branch and travel obliquely through the ON sublamina, forming gap junctions with ON cone BCs, neighboring Aii ACs, and itself. They extend laterally at the base of the IPL, collecting ribbon input from rod BCs. In contrast, mouse arboreal dendrites branch from a single primary dendrite, travel vertically through the IPL with limited self-interaction, and terminate at variable depths that align with the more broadly ramified axon terminals of mouse rod BCs. Synaptology reveals greater output in the OFF vs ON layer in mouse versus rabbit. Uniquely, descending axons of mouse ON cone BCs form gap junctions with Aii AC somas.

Conclusions: Lateral expansion of rabbit Aii ACs may be attributable to eccentricity. However, morphological differences correlate with connectivity differences. Comparative anatomy connectomics is essential for understanding implications of retinal structure on neuronal morphology and connectivity underlying network differences between the mouse and rabbit.
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Does phylogenetic relatedness influence response to heterospecific alarm cues in Brachyrhaphis rhabdophora?

December 30, 0020 12:00 AM
Chou, Audrey; Duffy, Alexandra; Johnson, Jerald (Brigham Young University)
Faculty Advisor: Johnson, Jerald (Brigham Young University, Biology)

Upon injury, fish release chemicals that cause fear and a dramatic change in behavior in nearby members of the species. Chemical alarm cues are released from injured epidermal tissue and provide an early warning signal for individuals to detect the presence of an active predator, and potentially increase the chances of individual survival. This research project investigates the conservation of alarm cue recognition and response across species boundaries by measuring the behavioral response of Brachyrhaphis rhabdophora to the alarm cues from five different species. Since these species will be of known phylogenetic relatedness, we will determine conservation of alarm cue response as a function of phylogenetic distance. I will also discuss the method of quantifying behavioral response through the use of a two-choice flume tank to measure both changes in activity and spatial avoidance upon alarm cue exposure.
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Cocoa Epicatechin Metabolites' affect on β Cell Proliferation and Cell Cycle

December 30, 0020 12:00 AM
Ross, Mimi; Tessem, Jeffery; Orton, Emily; Ekpo, Idongesit; Beales, Joseph (Brigham Young University)
Faculty Advisor: Tessem, Jeffery (Life Sciences; Nutrition, Dietetics, & Food Science)

In 2015 there were over 30 million Americans with diabetes and over 84 million Americans ages 18 and older had pre-diabetes. With diabetes being the seventh leading cause of death in the United States and becoming more prevalent the race is on to find a cure. One of the main problems with this disease is the decrease in functional β-cell mass. β-cells produce insulin to maintain blood glucose levels at healthy levels. Thus, if we can increase β-cell proliferation we are one step closer to curing diabetes. Cocoa epicatechins have been shown to be beneficial in blocking diabetes progression. Studies have shown that oligomeric and polymeric cocoa epicatechin extracts improve diabetes onset in a mouse model of Type 2 diabetes. We have demonstrated that the oligomeric fraction of cocoa epicatechins enhances β-cell proliferation in an in vitro model. Absorption studies have shown that while the oligomeric and polymeric forms are not readily absorbed in the gut, they are metabolized by gut bacteria and that these metabolites can be observed in circulation. Using flow cytometry we have studied how these phytochemicals: epicatechin, 5-phenylvaleric acid, Homovanilic acid, and Hippuric acid. Here we present the data regarding the effect of microbial cocoa flavanol metabolites on β-cell cell cycle during proliferation.
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Collared Peccary (Pecari tajucu) Group Size at La Selva Biological Station, Costa Rica

December 30, 0020 12:00 AM
Shin, Seungwon (Salt Lake Community College)
Faculty Advisor: Seaboch, Melissa (Salt Lake Community College, Anthropology)

The abundance of collared peccaries (Pecari tajucu) is crucial to study because they are a keystone species that plays a large role in their ecosystems. They consume fallen fruits and nuts, disperse seeds, and provide food for predators. Additionally, they are ecosystem engineers altering the landscape for other species. Previous studies have shown that collared peccaries at La Selva Biological Station travel in smaller groups (averaging 10 individuals per group) compared to peccaries at other Neotropical sites. La Selva Biological Station is located in northeastern Costa Rica and it consists of both primary and secondary (i.e. degraded) forests surrounded on three sides by farmland. Due to the general decline of mammals in degraded habitats, I predicted that the average group size of collared peccaries at La Selva will be even smaller than previously reported. I collected data at La Selva Biological Station for two weeks in May 2019. I used three census methods: total count sampling (counting all the species in a certain area), line transect sampling (counting all the species I see when I walk through a trail), and point sampling (standing at selected viewpoints and recording the species visible from that location). I observed 39 peccaries in 17 separate sightings. Group size ranged from 1 to 7 peccaries with an average of 2.3 peccaries per group. Eight sightings (20%) were of single peccaries. My hypothesis that peccary group size would be smaller than 10 individuals was supported. Some limitations of the study were low visibility due to the dense forest and the dispersed social organization of peccary individuals within the group. Both of these factors would underestimate the actual group size of collared peccaries. Nevertheless, the results support previous findings that peccary group size at La Selva are smaller than at other Neotropical sites.
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Effects of Exercise on Subjective Feelings of Fatigue: A Randomized Crossover Study

December 30, 0020 12:00 AM
Savage, Ryland; Stevens, Andrew; Hicks, Joseph (Brigham Young University)
Faculty Advisor: Bailey, Bruce (Brigham Young University, Exercise Science)

Purpose: This study examined the effect of different intensities of exercise on subjective feelings of fatigue both immediately following exercise and after 60 minutes of intense cognitive testing in men and woman.
Methods: These results come from a secondary analysis of a larger randomized crossover study examining the different levels of exercise intensity on cognitive performance. We recruited 228 men and woman to participate in the study. Each participant was tested after three exercise conditions: moderate (35% VO2 max), vigorous (70% VO2 max), and sedentary (no exercise). Each exercise condition was randomized and each test was separated by one week. After each 40-minute exercise condition, we administered a visual analog scale to evaluate subjective feelings of fatigue. This assessment of fatigue was delivered before treatment, immediately after treatment and then again after a variety of cognitive tasks were performed for the duration of one hour.
Results: For the sedentary condition, feelings of fatigue increased after the 40-minute intervention (p<0.001) and decreased after 60 minutes of cognitive work but remaining elevated compared to baseline (p<0.01). For the moderate condition, feelings of fatigue did not change immediately after exercise (p=0.063) but then increased after 60 minutes of cognitive work (p<0.001). For vigorous condition, feelings of fatigue increased after exercise(p<0.001) and remained elevated after performing the cognitive tasks (p=0.163). Following the 40-minute intervention, fatigue was highest after the sedentary condition, followed by the vigorous condition and did not change after completion of the moderate condition. Following 60 minutes of cognitive work, fatigue was highest in the vigorous condition (p<0.001) and did not differ between the sedentary and moderate conditions (p=0.063).
Conclusion: The results of this study show that moderate exercise has no significant impact on feelings of fatigue but exercise at a higher intensity and being sedentary increase fatigue. Doing cognitive work increases fatigue if exercise precedes the tasks but being sedentary beforehand decreases feelings of fatigue during cognitive tasks. This suggests cognitive work is usually draining, but if performed after sedentary or low activity states such as watching TV, cognitive work will be invigorating and help feel more alert.
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Differences in anthropometric characteristics between intermediate and high level climbers

December 30, 0020 12:00 AM
Miriam Reber; Ethan Del Toro; Holden Lyman; Weston Hargis; Travis Ficklin (Dixie State University)
Faculty Advisor: Ficklin, Travis (Dixie State University, Health and Human Performance)

In recent years sport climbing has increased in popularity, and with that have come questions regarding what factors improve performance. While multiple studies have examined the effect of anthropometric factors on injury in climbing, few have examined their relationship with climbing performance. Therefore, the purpose of this study is to compare the anthropometric measures of high-level to intermediate level climbers to determine if certain body types, or dimensions, lend themselves to better performance in climbing.

Twenty-one subjects were divided into an intermediate (INT) or high-level (HL) group based on highest graded climb achieved. Various measures including height, limb lengths, and experience. These were compared between the two groups using t-tests.

Significant differences were found in the number of days climbed per week (HL 2.9±1.1, INT 2.17±0.6, p = 0.03), and the ratios of upper arm to full arm length (HL 0.44±0.05, INT 0.41±0.02, p=0.03), and trunk to height (HL 0.26±0.03, INT 0.23±0.01, p=0.01). There were also statistical trends towards years of experience (HL 5.46±3.8, INT 3.39±1.8, p = 0.06), and trunk length (HL 44.96±7.1cm, INT 41.28±2.7cm, p=0.06).

The current data suggest that for the levels of climbing examined (5.9-5.13b on the Yosemite Decimal Scale) a greater trunk to height ratio, greater upper arm to arm length ratio, and increased frequency of practice (a variable within the climber's control) may positively impact climbing ability.
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Dopamine 2 receptors display rapid adaptation in response to acute ethanol administration

December 30, 0020 12:00 AM
LeBaron, Josh; Obray, J Daniel; Steffensen, Scott (Brigham Young University)
Faculty Advisor: Steffensen, Scott (Family, Home, and Social Sciences, Psychology)

Dopamine neurons in the substancia nigra (SN) and ventral tegmental area (VTA) are inhibited by dopamine (DA) via dopamine 2 receptor (D2R) activation. D2R expression in the striatum is a well-known biomarker for brain DA levels, drug abuse, and dependence. Markers of D2R expression are not only detectable in the brain but are also expressed in peripheral tissues, including the blood, where DA appears to play a pivotal role in mediating communication between the nervous and immune systems. Alteration in lympocytic D2Rs are seen in chronic psychostimulant use (Ersche et al., 2011). For the last two decades it has been generally accepted that D2R expression in the striatum is reduced by chronic ethanol use. Additionally, research has suggested that these changes mirror changes in DA levels in the striatum and predict risk of relapse. Despite this, the timecourse over which these changes occur has not been demonstrated. Further, recent research has challenged both the reduction in D2R expression produced by chronic ethanol and the mechanism whereby it was believed to be produced (reductions in striatal DA levels). This research has suggested that alterations in D2R levels may be due to disruption of sleep in individuals with substance use disorders. Here we demonstrate that dopamine 2 receptor expression in the brain and the blood follows brain and blood dopamine levels on a timescale of minutes to hours following an acute dose of ethanol. This research provides evidence for transient changes in D2R expression following a single dose of ethanol.
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Determining the Function and Structure of Cms1, A Type V CRISPR Effector Endonuclease

December 30, 0020 12:00 AM
Tonks, Adam; Domgaard, Hannah; Crowley, Valerie; Neumann, Gina; Keiser, Dylan; Metcalf, Josie; Guo, Hongjie; Zhou, Yi; Begemann, Mathew; Taylor, David; Jackson, Ryan (Utah State University)
Faculty Advisor: Jackson, Ryan (College of Science, Chemistry and Biochemistry)

Cms1 is a Type V endonuclease that contains a novel domain, shares little sequence homology with other Type V endonucleases, and in some organisms, is found near genes coding for other single-subunit nucleases. Studies in rice (Oryza sativa) have shown Cms1 capable of RNA-directed DNA editing. However, the mechanism of DNA cleavage remains unknown.
Here we present biochemical data that demonstrate Cms1 from Sulfuricurvum processes an RNA guide and binds/cleaves single- and double-stranded DNA through RuvC nuclease motifs. 2-D classification of structures obtained by negative staining electron microscopy show a major conformational change between SuCms1 bound and unbound to an RNA guide. The predicted global structure appears to be different than those reported for other Type V effectors. These data provide for a greater understanding of Type V endonucleases and may provide an alternative tool for genome editing applications.
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Effect of Gender on Shear Wave Elastography and Cross Sectional Area of the Gastrocnemius in Senior Athletes.

December 30, 0020 12:00 AM
Hutchison, Cortland; Preece, J. Caleb; Seibold, Tanner; Feland, J. Brent (Brigham Young University)
Faculty Advisor: Feland, Brent (Life Sciences, Exercise Science)

BACKGROUND: Muscle morphology changes with age and the fibrous/fatty infiltration should affect the overall stiffness of aging muscle. However, little info intrinsic stiffness as measured by SWE is available on aging muscle and the effect of gender using this measurement is not clear.
PURPOSE: This study aimed to determine how gender affects cross sectional area (CSA) and SWE of both the medial and lateral heads of the gastrocnemius muscle of the dominant leg in active older athletes participating in the HuntsmanWorld Senior Games.
METHODS: Data was collected from 116 volunteers (participants in the Huntsman World Senior Games) in St. George, Utah, 2019. Subjects (62 males: mean age = 68.9 ± 7.8 yrs, Ht = 177.4 ± 8.1 cm, Wt= 85.4±20 kg; 54 females: mean age = 66.9 ± 8.5 yrs, Ht =164.4 ± 7.2 cm, Wt= 69.8±18 kg) signed an approved consent form and then lay prone on a treatment table for ultrasonic measurement of both CSA and SWE of both heads of the gastrocnemius.
ANALYSIS: All data were analyzed a generalized linear model analysis using SPSS ver25 comparing CSA and SWE of both medial and lateral gastrocnemius heads by gender with age, height and weight as covariates.
RESULTS & CONCLUSION: We hypothesized that gender would affect both CSA and SWE with males exhibiting increases in both CSA and SWE values. We found a significant difference in CSA of both the medial and lateral gastroc (p=.000 for both) between genders, but no significant difference in lateral gastroc SWE (p=.337) or medial gastroc SWE (p=.320). Both age (p=.004) and weight (p=.000) were also found to significantly affect CSA and SWE between genders. The larger CSA values for men in this study may be more of a function of overall body size and weight since both populations are active athletes.
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Effects of Flavanols on β-cell proliferation.

December 30, 0020 12:00 AM
Tessem, Jeffery; Lloyd, Trevor; Brown, Nathan (Brigham Young University)
Faculty Advisor: Tessem, Jeffery (Brigham Young University; Nutrition, Dietetics and Food Science)

Diabetes is a global epidemic affecting millions of people. The total estimated cost of diabetes in the U.S. during 2017 was 327 billion dollars [1]. Diabetes is characterized by the loss of pancreatic β-cell function which is caused by an autoimmune disorder in Type 1 diabetes or insulin resistance and β-cell exhaustion in Type 2 (T2D) diabetes. Lifestyle changes in diet are beneficial in treating T2D. Phytochemicals are commonly utilized in these diets, and recent studies show diets high in flavanols exert beneficial bioactivity for β-cells. While flavanols demonstrate beneficial effects on β-cells, these flavanols are rarely observed in circulation, suggesting a necessary intermediate step. Flavanols are metabolized by gut bacteria to smaller metabolites that are absorbable. We hypothesize that these gut bacteria derived flavanol metabolites cross the gut and affect β-cell function. We have fed rats catechin supplemented or unsupplemented diets and collected urine as a means to isolate all absorbable gut flavanol metabolites. Here we present the effects of these absorbed metabolites on β-cell proliferation. This study begins to explain the mechanism by which flavanols exert their beneficial effect on glucose metabolism through the β-cell.
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CRISPR-based identification of Salmonella in local waterways

December 30, 0020 12:00 AM
Hirschi-Forster, Jeanallie; Mendoza, Matthew; Van Oene; Nicholas ; Payton, Jullian (Weber State University)
Faculty Advisor: Clark, Daniel (Science, Microbiology)

The purpose of this research is to obtain quantitative data about possible sources for Salmonella contamination including tributaries to the Great Salt Lake, namely, the Jordan River, Weber River, and Bear River in Utah. We will also analyze specific water and soil sources near poultry farms for possible contamination. In recent studies, there is a greater number of produce items that have been found to contribute to Salmonella outbreaks. Contaminated water used for irrigation of these crops has been implicated as the causative agent for food contamination.

Bacteria found in these waterways are enriched using selective and differential media. This means, the media provides Salmonella species with required nutrients to grow effectively while differential media inhibits the growth of non-Salmonella species. The enrichment media that is used during this process is 3 X Tryptic Soy Broth and Gram-Negative broth. Gram negative broth is used as an enrichment step, but also selective in that it inhibits growth of other organisms. The two types of differential media would be XLT4 and MSRV. Salmonella is a motile bacterium and thus branches out from its original location of inoculation. This creates a halo-like growth pattern that makes it possible to differentiate Salmonella on MSRV plates. Once Salmonella is confirmed through the MSRV and XLT4 media, sequencing of its two CRISPR loci is completed. These two chromosomal regions have been shown to be distinct in different serovars, and as such, they can be used to distinct what subspecies is present in the sample.
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Chemogenetic stimulation of connexin-36 expressing VTA GABA neurons enhances DA neuron firing rate

December 30, 0020 12:00 AM
Tuttle, Jared; Payne, Andrew; Obray, J Daniel; Steffensen, Scott (Brigham Young University)
Faculty Advisor: Steffensen, Scott (Family, Home, and Social Sciences; Psychology)

A subpopulation of ventral tegmental area (VTA) GABA neurons express connexin-36 (Cx36) gap junctions (GJs). Activation of GJ-mediated electrical coupling between VTA GABA neurons supports brain stimulation reward and alcohol reward is lowered in Cx36 KO mice due to a hyper-dopamine (DA) state. The aim of this study was to further evaluate the role of a subpopulation of Cx36+ VTA GABA neurons in alcohol reward and dependence. To accomplish this study, we customized a Gq-coupled Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) viral vector to only express in Cx36+ neurons (AAV8.hCx36.hM3D(Gq)-mCherry.WPRE.rBG) in the VTA. The hM3Dq viral vector was infused into male CD-1 GAD GFP mice and male Wistar rats. The animals were then given 10-14 days to recover prior to experimentation. A control virus (AAV9.CB7.CI.mCherry.WPRE.rBG) was used for comparison. We implemented standard cell-attached mode electrophysiology to evaluate the effects of clozapine-n-oxide (CNO; the ligand for DREADDs) on VTA GABA and DA neuronal activity. We found a robust enhancement of VTA GABA neuron firing rate in hM3Dq+ neurons with 20 _M CNO ex vivo. Surprisingly, while investigating CNO effects on VTA DA neuron firing rate, we found that CNO activation of hM3Dq+ VTA GABA neurons increased DA neuron activity, suggesting that Cx36+ VTA GABA neurons indirectly modulate local VTA DA neurons. Intraperitoneal CNO (3 mg/kg) also enhanced the firing rate of VTA GABA neurons in vivo. Administration of CNO reduced ethanol consumption (drink-in-the-dark paradigm) in both ethanol naïve and ethanol dependent hM3Dq-injected mice as compared to controls, suggesting that activation of Cx36+ neurons in the VTA is enough to block ethanol consumption in both naïve and dependent animals. Taken together, these findings support previous studies indicating that enhanced electrical coupling between VTA GABA neurons is rewarding and promotes reward and lowers the hedonic value of ethanol.
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