Life Sciences

Hirschi, Blake; Pickett, Brad; Thompson, Jared; Telford, Mady; Berges, Bradford (Brigham Young University)
Faculty Advisor: Berges, Brad (Life Sciences, Microbiology and Molecular Biology)

Staphylococcus aureus (S. aureus) is a commensal bacterium commonly found amongst livestock and near 30% of humans' nostrils. However, through acquisition of certain genes S. aureus may develop antibiotic resistance such as in methicillin-resistant Staphylococcus aureus (MRSA). One hypothesized component lending to acquisition of genetic resistance in S. aureus is the synthesis of colony biofilms. Biofilms are comprised of a variety of substances including secreted polysaccharides, protein and even extracellular DNA. Our work postulates that extracellular DNA-based biofilms will transfer genes for antibiotic resistance at a higher rate than in polysaccharide/protein biofilms. Through employment of polymerase chain reaction (PCR), we aim to characterize a wide sample of methicillin-susceptible S. aureus (MSSA) human associated strains and MRSA livestock associated strains for multiple antibiotic resistances. Co-inoculating pairs of human associated and livestock associated strains, each lacking the other's resistance genes, will provide an environment wherein biofilm-mediated gene transfer may occur. Further pairing based on biofilm composition (DNA or polysaccharide/protein) will yield data concerning which biofilm facilitates gene transfer more efficiently. Subsequent genotyping will confirm whether resulting isolates acquired new antibiotic resistance through biofilm-mediated transfer, thus increasing pathogenicity.

Bartlett, Ashley; Phatak, Sumira; Hintze, Korry; Benninghoff, Abby (Utah State University)
Faculty Advisor: Benninghoff, Abby (College of Agriculture and Applied Sciences; Animal, Dairy, and Veterinary Sciences Department)

The gut microbiome modulates various physiological functions related to cancer development including inflammation, cell proliferation, apoptosis, and angiogenesis. Patients with inflammatory bowel disease have a microbiome distinct from healthy controls with consistent observations of reduced gut biomass, decreased diversity within the community, and altered relative abundance. Although a consensus cancer-related microbiome has not been identified, several pathogenic species play an instrumental role in the progression of colitis and tumorigenesis, including: Streptococcus bovis, Helicobacter pylori, Enterococcus faecalis, Clostridium septicum, and Escherichia coli. Gut microbial composition is highly responsive to diet and inadequate intake of micronutrients is a critical feature of the Western dietary pattern. Gut dysbiosis has been proposed to further limit mineral uptake and impair vitamin synthesis, predisposing the host to micronutrient deficiency. Dietary bioactives, such as those in green tea, may function as a mediator between the gut microbiome and basal diet to ultimately prevent colitis associated colorectal cancer (CAC). The overarching objective of our work is to determine the impact of ancestral or multi-generational consumption of the total Western diet (TWD) in a murine model of CAC. Our previous work is the first to investigate how diet induced transgenerational inheritance affects CAC outcome. Our data suggested that multigenerational patterns of exposure to the TWD altered both phenotype and gene expression in third generation offspring. Supplementation with green tea appeared to be most promising after consumption of TWD for multiple generations. Considering that gut microbes are inherited maternally after colonization during vaginal birth, the gut microbiome is a missing piece in this disease model puzzle. The hypothesis of our current project is to investigate whether intake of TWD influences the transmission of microbes and whether CAC outcome is reflected by altered gut microbial composition. Based on other work, we expect the healthy control to possess an abundance of varied bacterial taxa that maintain protective epithelial barrier function and overall homeostasis. On the other hand, a high fat diet would promote increased intestinal permeability, a substantial shift at the phyla level, and increased production of pro-inflammatory cytokines. After TWD consumption, we expect an overall negative phenotypic outcome within the gut microbiome, that includes a breakdown of the epithelial barrier and introduction of pathogenic bacteria. These harmful bacteria tend to thrive on simple sugars that are common in the Western dietary pattern and tend to produce metabolites known as endotoxins that promote dysbiosis.

Leavitt, Amanda; Harris, Heather; Szanter, Kathryn; Stokes, Alexis (Weber State University)
Faculty Advisor: Dunn, Charles (Weber State University, Child and Family Studies); Hubler, Daniel (Weber State University, Child and Family Studies); Osai, Keith (Weber State University, Child and Family Studies)

How a child is parented can influence their success socially, mentally, physically, and emotionally. Agarwal (2017) states that "Parenting plays the most important part in any child's life, it can help a child by teaching them to deal with people, situations and adapt to a better living standard" (p.1335). Parents help form worldviews, shape a child's attitude towards personal achievement, teach how to approach adversity in life, and satisfy their needs whether it be psychological and/or physiological. Much is known about how the base of one's childhood is built upon one's primary caregivers' parenting style, however, less is known about the intergenerational transmission of parenting philosophies.

The current study was designed to assess how parenting styles affect child delinquency and bullying. Through social media invitations and snowball sampling, 200 people accepted invitations to participate in an online survey incorporating both open-ended and quantitative items. Participants were asked to reflect on how they were parented and then state what they have maintained or changed in their own parenting styles. Considering the rich nature of the responses to the qualitative items, a corroborative narrative came together through personal stories.

Through thematic analysis, several themes emerged. When participants reported being parented with: open communication, flexibility, love, trust, and higher expectations they wanted to keep those traits. When asked what participants carried on from their parents one participant stated, "Cherish the family and the moments we have together." Additionally, 28% (n = 113) of our participants shared the importance of spending quality time together. However, when participants' parents did not display those traits, most participants indicated that similar traits, namely communication, flexibility, love, quality time, trust, and higher expectations were desired in their homes. The findings from the current study can be used to inform future parenting research assessing influence on subsequent generations.

Olsen, Lindsey; Frandsen, Paul (Brigham Young University)
Faculty Advisor: Frandsen, Paul (Life Science, Plant and Wildlife)

Trichoptera (caddisflies) have evolved to become the most diverse, exclusively aquatic insects, yet many of the genomic changes that contribute to Trichoptera's the success of this order of insects are still unknown. Trichoptera and Lepidoptera (moths and butterflies) are reciprocally monophyletic meaning that they both share their most recent common ancestor. Despite being closely related, Trichoptera have evolved into the most diverse, exclusively aquatic insects, whereas, Lepidoptera have evolved to become a diverse, almost exclusively terrestrial insect (Holzenthal et al. 2007). Trichoptera and Lepidoptera are the subjects of scientific inquiry because they are both capable of spinning silk. Trichoptera produce silk as larvae and use it to make cases or fixed retreats. Trichoptera silk is of particular interest because its properties allow for it to be an underwater adhesive. While other research has focused primarily on the evolution of Trichoptera silk, little research has been done to identify the evolutionary innovations that allowed Trichoptera to adapt and diversify in an aquatic environment. Our research focuses on identifying the genomic basis of their evolutionary innovations. We report the genome annotation of four newly sequenced Trichoptera species Hesperophylax magnus, Parapsyche elsis, Philanisus plebeius, and Rhyacophila brunnea. These annotations will reveal levels of homozygosity, conserved elements, and gene duplications. We then conducted a genome-wide search for gene family expansions and retractions using CAFE, in order to identify genomic regions that could contribute to Trichoptera's unique qualities and evolutionary history.

Holzenthal R. W., R. J. Blahnik, A. L. Prather, and K. M. Kjer, 2007 Order Trichoptera Kirby, 1813 (Insecta), Caddisflies*. Zootaxa 1668: 639—698. https://doi.org/10.11646/zootaxa.1668.1.29

Armitstead, Annie; Grether, Lara; Creech, Kealani (Brigham Young University)
Faculty Advisor: Watt, Richard (Brigham Young University, Biochemistry)

Lateral Flow Immunoassays (LFI) are simple tests that detect specific levels of antigens or antibodies in patient samples. Requiring only a few minutes, small sample sizes and no read-out equipment, LFI�s are an invaluable and time efficient testing technique. Made up of multiple layers they facilitate the capillary flow of a sample through protein detection zones and can be developed to detect virtually any disease or condition.

Despite the attractive attributes of these tests, the assembly of an LFI strip requires expensive machines, trained personnel, and materials not easily accessible to low-resourced labs or clinics. Developing an innovative point-of-care platform designed to be streamlined, low-cost, and intelligible to the unskilled would open the door of medicine to even the most underprivileged clinics in the world.

We are currently developing a paper LFI that uses a single sheet of copy paper with the ability to filter whole blood as well as replacing high-priced machines with stencils and pens which can still deliver detection proteins to the designated test zones. This avenue of testing is supported by previous experiments we have done with protein pens and tagged antibodies. Using anti-mouse and anti-hCG antibodies as our control and test lines respectively, we spike our sample with hCG mouse antibodies tagged with nanoparticles, and we are able to see binding of both proteins with their respective antibodies. We have seen results in our new testing technique that is easily comparable with currently commercialized LFI's: visual results of binding within 1 min, successful transformation of printer paper into a functional binding platform, and consistent protein binding at a 1/10^5 concentration. Once this concept can be translated to different inks in order to diagnose a plethora of varying conditions, we'll be able to detect diseases and other important biomarkers no matter the limiting low-resource circumstances.

Boyce, Zach; Smith, Calvin; Martin, Ashlyn; Ketch, Yuko; Dugan, James; Wright, Cole (Brigham Young University)
Faculty Advisor: Jeffrey, Edwards (Brigham Young University, Physiology and Developmental Biology)

Post-traumatic stress disorder (PTSD) is a complex psychological disorder that affects about 1 of 4 individuals after a stressful/traumatic experience. One common model to induce PTSD in rats is social defeat (SD) combined with chronic light exposure. First, we screened rats for natural anxiety to use in the SD protocol. Next, elevated plus maze (EPM) and light-dark transition (LDT) tests were used to detect anxious behavior after SD. The SD protocol induced significant anxious behavior when compared to controls. Next, we performed long-term potentiation (LTP) field electrophysiology synaptic plasticity physiology experiments in brain slices of the ventral hippocampus (VH) and basolateral amygdala (BLA), regions known to have altered enhanced plasticity in PTSD. SD significantly increased LTP in the VH (~25% greater than control) and BLA (~35% greater than control). To determine whether a prophylactic treatment could prevent the physiological changes of PTSD, we simultaneously administered two drugs at 10 mg/kg doses by intraperitoneal injection one week prior to and for the duration of SD. The first, propranolol, is a beta-adrenergic receptor antagonist, and the second, mifepristone, is a glucocorticoid receptor antagonist; thus, treatment would target the action of stress hormones altered in PTSD. To determine whether a prophylactic treatment could prevent the physiological changes of PTSD, propranolol and mifepristone, antagonists of two stress receptors, were simultaneously administered at 10 mg/kg doses by intraperitoneal (IP) injection one week prior to and for the duration of SThese drugs significantly decreased LTP in the VH and BLA back to near-control levels while SD rats with vehicle injections still had elevated LTP. However, SD drug-treated rats did not show significant reductions in anxious behavior compared to non-injected SD rats and also exhibited significantly more anxious behavior than control rats, suggesting the IP injection induced added stress. Next, we used rtPCR to examine gene expression of drug targets and plasticity markers to determine potential mechanisms for observed LTP changes. In both the VH and BLA, SD was associated with a significant decrease in glucocorticoid and mineralocorticoid receptor expression, which was restored to control levels under drug treatment. Overall, our data suggest that propranolol and mifepristone together may be a potential prophylactic treatment for preventing PTSD through a mechanism likely mediated by glucocorticoid/mineralocorticoid receptors.

Hannah A. Veltkamp, Sydney Houghton, Michael T. Stevens (Utah Valley University)
Faculty Advisor: Stevens, Micheal (Utah Valley University, Biology)

Netleaf hackberry (Celtis reticulata) is a deciduous shrub native to the southwestern United States and northern Mexico. Individual shrubs can be long-lived, but newly established stands of hackberry are rare. The lack of juvenile hackberry in the wild could be due to low germination rates reported in both laboratory and field settings. The seeds of hackberry are embedded in drupes that are an important source of food for birds and small mammals. Animals likely play an important role in seed dispersal, and passing through a digestive tract could increase the germination rates of hackberry seeds. Passage through the digestive tract of a mammal can increase the germination rates for some plant species, but not for others. We hypothesized that passage through the digestive tract of a coyote would increase the germination rates of C. reticulata. To test this hypothesis, we collected 17 coyote scats containing visible hackberry fruits from along the Bonneville Shoreline Trail east of Provo, Utah, using latex gloves. Each scat location was recorded using a GPS unit. After collecting each scat, we found the closest hackberry shrub and picked a sample of fresh hackberry fruits from it. All samples were cleaned and cold stratified and then planted into cone-tainers containing a potting soil mix and placed in the Utah Valley University greenhouse. We sowed 20 seeds from each of the 17 coyote scats and

20 seeds from each of the neighboring hackberry bushes for a total of 680 seeds. The 680 cone-tainers were labeled with plastic stakes and randomly positioned into trays that were randomly distributed on a bench in the greenhouse. The seeds, and later seedlings, were watered as needed (typically three days/week). On watering days, we checked for newly-germinated hackberry seedlings and recorded their date of emergence. Near the end of the experiment, we measured the height of each seedling. The germination rate of hackberry seeds that had passed through the

digestive tract of a coyote did not differ from the germination rate of seeds from fresh-picked fruit (42.7% vs. 46.5%, respectively; _ 2 = 0.558, df = 1, p = 0.455). However, on average, the coyote-treatment seeds took just over half as many days to germinate as did the seeds from fresh-picked (undigested) fruit (35 days vs. 69 days, respectively; p < 0.001). The seedlings from coyote-treatment seeds were 9.5% taller than were the seedlings derived from seeds from undigested fruit (6.4 cm vs. 5.8 cm, respectively; p < 0.001). Our results show that consumption by coyotes can benefit hackberries by enabling their seeds to germinate earlier in the year when

conditions for establishment are good. The earlier start on germination that coyote-ingested hackberries get translates to increased height and likely a higher rate of survival in the field.

Elison, Weston; Bauchle, Casey; Bunker, Libby; Stephens, Samuel; Tessem, Jeffery (Brigham Young University)
Faculty Advisor: Tessem, Jeffery (Brigham Young University; Nutrition, Dietetics and Food Science)

Type 2 Diabetes (T2D) effects hundreds of millions of people worldwide, with that number increasing rapidly. It is characterized by increased insulin resistance and dysfunctional insulin secretion. The beta cell of the pancreas is the primary insulin secreting tissue, found in the endocrine tissue of the pancreas called islets of Langerhans. In T2D beta cells become glucose intolerant and disease progression is characterized by loss of functional beta cell mass. Previous studies have shown that the transcription factor Nkx6.1 is vital for beta cell differentiation, identity, and insulin secretion. Research has indicated that Nkx6.1 expression and protein levels decrease in pancreatic islets from human donors with T2D. Our data indicates that glucolipotoxicity, a common model for obesity and diabetes in cell culture, leads to decreased Nkx6.1 mRNA expression, protein levels and nuclear localization in Ins-1 832/13 cells. Nkx6.1 regulates genes in the nucleus , and its loss inhibits proper insulin secretion. We propose that reactive oxygen species created by metabolism of excess fuel decreases Nkx6.1 expression and Nkx6.1 target gene expression, as measured by quantitative polymerase chain reaction (qPCR). Also, increased glucose concentrations causes increased Nkx6.1 protein degradation and translocation out of the nucleus. Protein levels will be measured by western blot and localization by confocal microscopy. In order to understand how these changes effect beta cell function, we will measure glucose stimulated insulin secretion by sandwich Enzyme Linked Immunosorbent Assay (ELISA). We further propose that Nkx6.1 overexpression will restore beta cell function. These results will assist in unraveling the cause of beta cell dysfunction in T2D.

Pugh, Sam; Valentine, Julie; Miles, Leslie (Brigham Young University)
Faculty Advisor: Valentine, Julie (Brigham Young University, College Of Nursing); Miles, Leslie (Brigham Young University, College of Nursing)

Rape is generally recognized as a sexual assault by a male perpetrator to a female victim. However, sexual assault is a crime that affects all genders. Although the majority of rapes are male to female, current findings indicate that one in seventy-one men will be raped in their lifetime. Over time, research has recognized the psychological effects and underreporting that ail male rape victims. However, very little has been reported regarding short tandem repeat (STR) DNA findings from sexual assault kits of male victim rapes. These STR DNA profiles prove to be highly influential in the detainment and prosecution of perpetrators. After an extensive search for earlier publications concerning the topic, only three articles were found to have relative correlation to this topic. Current best practice is to obtain STR DNA profiles from sexual assault kit samples to enter into the FBI Combined DNA Index System (CODIS). The purpose of this study was to evaluate DNA analysis findings from 266 sexual assault kits collected from male sexual assault victims and compare predictors for the development of CODIS-eligible STR DNA profiles of male victims to female victims. Our study methodology is an exploratory, retrospective design to identify male rape victims from a sample size of 5,758 victims who received sexual assault forensic examinations with sexual assault kit evidence collection. Approximately 5% of the victims in our study were male (N=266). Male victims were found to have more physical or mental impairments. Male victim cases revealed significantly less development of STR DNA profiles and CODIS-eligible DNA profiles of the perpetrator (p=.007). Due to low STR DNA profile yields and increased targeting of mentally impaired or otherwise vulnerable male victims, we must improve our response to male victims to ensure justice to all victims of sexual assault.

Smith, Mick; Desdames, Chloe (University of Utah)
Faculty Advisor: Seaboch, Melissa (University of Utah, Anthropology)

Census and sampling work are important because they provide critical information on population size, distribution, and habitat preference — all important factors in conservation. La Selva Biological station is located on the north eastern side of Costa Rica and is a protected biological reserve. It is home to three species of primates including Alouatta palliata, commonly known as the mantled howler monkey. It is comprised of primary forest that has been undisturbed by human forces and secondary forest that is regenerating from past disturbances, such as deforestation. Past research conducted on howler monkeys shows they prefer primary forest over secondary because primary forests have higher species richness and a wider range of trees which provides food for howler monkey's selective diet. I predict that the majority of A. palliata in Costa Rica will be located in primary forest because it offers more resources. I censused 11 established trails at La Selva (two trails in primary forest, seven trails in secondary forest, and two trails crossing both forest types). For each howler monkey encountered, I recorded the location, forest type, and group size. I identified four different groups of A. palliata with group size ranging between 6-10 individuals. One group was located in primary forest and three groups in secondary forest; thus, my hypothesis that A. palliata would prefer primary forests was not supported. Anecdotally, A. palliata were observed more frequently around rivers or streams. This could indicate that rather than being concerned with primary versus secondary forest, they prefer riparian habitats found along the banks of rivers or other actively moving sources of water. A study conducted by Stoner found howler monkeys in riparian habits supporting this hypothesis. This type of research continues to provide critical information for understanding primate's habitats which helps with conservation of species.

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.

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.

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.

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.