Katie Leibel Honors Portfolio

Katie Leibel\u27s honors portfolio captured in January 2020

Investigating the ovarian response to endotoxemia

The ovary is responsible for production of steroid hormones and gametes in the female. It is endowed with a finite pool of primordial follicles, established in utero, that serve as the source of oocytes during a female’s reproductive lifespan. Alterations to ovarian function and signaling can result in disruptions to steroid hormone production, follicle activation, and oocyte quality. The degree of disruption is dependent on the developmental or estrous cycle stage of the animal as well as the duration of the perturbation. Inflammation can have deleterious effects on ovarian signaling and function, and can arise from multiple sources, such as endotoxemia, or increased levels of lipopolysaccharide (LPS) in blood. One major source of LPS is the intestine, where stresses such as hypoxia due to heat stress, high fat diets, or obesity can induce increased intestinal permeability and allow passage of LPS from the intestinal lumen into circulation. LPS signaling via its receptor, toll-like receptor 4 (TLR4), may induce inflammation in the ovary, potentially compromising oocyte and follicular quality, resulting in reduced fertility. This thesis investigated the central hypothesis that increases in circulating LPS would alter ovarian signaling and function as evidenced by activation of the TLR4, phosphatidylinositol 3 kinase (PI3K), and steroidogenic pathways. To test this hypothesis, we utilized three animal model-LPS exposure schemes in pigs: post-pubertal chronic LPS infusion, post-pubertal heat stress (HS), and pre-pubertal high fat diet (HFD). We analyzed ovarian protein and mRNA abundance via western blotting and qRT-PCR, as well as quantification of 17β-estradiol, progesterone, and LPS binding protein concentrations via ELISAs. Overall, our findings demonstrate that the ovary is responsive to LPS as demonstrated by increased ovarian TLR4 in an LPS infusion but not HFD model. We also discovered alterations to the PI3K and steroidogenic pathways in our HFD model not seen with the other exposure paradigms, indicating a potential effect of developmental age or an alternate effector mechanism in these pigs. Taken together, these data demonstrate the alterations in ovarian function due to different exposures to LPS in isolation or combination with other physiological changes. This understanding is vital to the development of amelioration strategies to reduce infertility

Strange Bedfellows: Understanding the Motives Behind the U.S.-Saudi Relationship from 1961-2016

After Jamal Khashoggi’s murder, many Americans questioned why the United States, a proud democracy, continued to work alongside the repressive Saudi monarchy. This thesis addresses this question and explains how this partnership evolved between 1961 and 2016. Throughout this work, I explore the principal interests that drove and maintained the U.S.-Saudi relationship over time. Although the United States claimed to champion human rights in its foreign policy decision-making, I argue that mutual oil and security interests, rather than liberal reform, directed the two countries’ relations.Histor

Effects of Prescribed Fire and Habitat on Golden-winged Warbler (Vermivora chrysoptera) Abundance and Nest Survival in the Cumberland Mountains of Tennessee

Golden-winged Warbler (Vermivora chrysoptera) populations in Appalachia have declined precipitously over the past 45 years. The primary objective of my study was to monitor the response of Golden-winged Warblers to prescribed fire treatments on reclaimed coal mines in the North Cumberland Wildlife Management Area, Tennessee. Presence-absence surveys were conducted on eight mountain-top study sites and nest searching/monitoring was conducted on two additional sites, 2009-2011. I expanded on previous research of Golden-winged Warbler territory and nest-site selection by determining differences within main effects between used and unused territory plots, as well as used and unused nest-sites. Of my two nest-searched sites, Ash Log and Massengale Mountains, only Massengale received annual prescribed fire treatments, 2007-2011. Thus, analysis was conducted separately for these two study sites. I also modeled the effects of fire history, as well as temporal and biotic factors, on the variation in daily nest survival rates (DSR). I documented a population increase on Massengale, and no change on four sites. Population decline on three unmanaged sites was correlated with a decrease in shrub and/or Rubus spp. cover, and an increase in sapling height. Territories contained more shrub cover \u3e1 m in height on Massengale and Rubus spp. cover was greater inside territories than on unused plots on Ash Log. No nest-plot variables differed between nest and non-nest plots. The best-supported model of DSR included the effect of year, quadratic time, and the presence of Rubus spp. in nesting substrate. Nesting success was highly variable across years; 10.8 ± 5.4% in 2009, 57.5 ± 8.8% in 2010, and 29.3 ± 10.0% in 2011. With respect to time, nest survival was greatest during peak of nest initiation in early May, declined through the middle of the nesting season, and increased again through the latter half of the season (27 June). Nest success decreased with the presence of Rubus spp. in the nesting substrate. I detected no negative relationship between daily nest survival and fire history. My study suggests that prescribed burning on reclaimed coal mining land is a viable management practice for the creation and maintenance of Golden-winged Warbler breeding habitat

Facebook and Its Users: Using Grounded Theory to Understand Perceived Interactivity as a Constraint in the Rhetorical Situation

The general term interactivity has been used in a variety of disciplines to describe phenomena that occur in website interfaces; however, definitions and explanations about what constitutes interactivity and how it functions do not consider the specific ways in which interactivity can function and be perceived by users in specific rhetorical situations. In this study, I address the problems with the literature about general interactivity in writing studies and in other disciplines such as computer science, advertising, marketing, and communication studies by distinguishing between two types of interactivity—functional and perceived. I situate the different types of interactivity rhetorically, which can enable interface designers to create potential interfaces to be more rhetorically appropriate for end users based on their purposes or reasons for engaging with an interface. In this study, I investigated the ways that perceived interactivity appears as a constraint within the rhetorical situation of the Facebook interface. I also was interested in the ways a user\u27s purpose determines which features of an interface are perceived as interactive. In order to answer my research questions, I used the social networking website Facebook as the site of study. I used grounded theory as a framework to guide my interpretation of the data I collected. I triangulated my data using surveys, case study interviews, and genre analysis to answer my research questions. Grounded theory enabled me to develop theory from the data I collected in order to draw conclusions from my data sets, which I then evaluated further to confirm the results I reported. My results indicate that perceived interactivity functions as a constraint within the rhetorical situation of the Facebook interface enabling users to determine which tasks they can and cannot accomplish through the interface. My research has implications for writing studies—particularly technical/professional communication, rhetoric and composition, and new media. Research that further investigates the ways perceived interactivity functions within specific types of rhetorical situations can enable interface designers to create texts that support users to achieve a variety of purposes for engaging with a website

Reproductive Biology of the Bowfin, Amia Calva Linnaeus, from the Green Bottom Wildlife Management Area, Cabell County, West Virginia

The bowfin, Amia calva Linnaeus, is the only extant species of the family Amiidae. The Green Bottom Wildlife Management Area (GBWMA) is the home of the only known reproducing bowfin population in the state of West Virginia. The GBWMA (38°35\u27 35 N, 82°14\u27 55 W) is located along the Ohio River 26 km northeast of Huntington, West Virginia. The area (ca. 364 ha) contains a valuable wetland habitat (ca. 57 ha) in the southwestern portion of the state. A study of the reproductive biology of the bowfin became important when the u.s. Army Corps of Engineers proposed a habitat modification to add replacement marshland by building levees and dykes. The information from this study will establish a baseline for reproductive activities of the bowfin prior to habitat perturbation so that their adaptation to the new environ­ ment can be accurately determined. Bowfin were collected seasonally (spring, summer/ and fall) by hoop nets, pillow traps, seines, and electrofishing, with the nets and traps being most successful. Attempts were made to determine the duration of the reproductive season by: (1) calculating the seasonal gonadosomatic index (GSI), which was highest in spring fish, lowest during the summer season, and greatly increasing in the fall season, (2) observing seasonal gonadal development using histological techniques, which confirmed that most development occurs during the fall season, and (3) noting the appearance of newly hatched or Y-0-Y larvae, which were collected on May 15. Observations were also made on spawning colors (found only in spring males no younger than two years of age), fecundity (x = 22,575), egg diameters (1-2 mm) , and sexual dimorphism (meristics and morphometries), which showed significant differences in total length, standard length, body depth, and predorsal length. Females were slightly larger for all four characteristics. The results from this investigation will be compared with previous literature reports

Risk factors and mortality associated with multimorbidity in people with stroke or transient ischaemic attack: a study of 8,751 UK Biobank participants

Background: Multimorbidity is common in stroke, but the risk factors and effects on mortality remain poorly understood. Objective: To examine multimorbidity and its associations with sociodemographic/lifestyle risk factors and all-cause mortality in UK Biobank participants with stroke or transient ischaemic attack (TIA). Design: Data were obtained from an anonymized community cohort aged 40–72 years. Overall, 42 comorbidities were self-reported by those with stroke or TIA. Relative risk ratios demonstrated associations between participant characteristics and number of comorbidities. Hazard ratios demonstrated associations between the number and type of comorbidities and all-cause mortality. Results were adjusted for age, sex, socioeconomic status, smoking, and alcohol intake. Data were linked to national mortality data. Median follow-up was 7 years. Results: Of 8,751 participants (mean age 60.9±6.7 years) with stroke or TIA, the all-cause mortality rate over 7 years was 8.4%. Over 85% reported ≥1 comorbidities. Age, socioeconomic deprivation, smoking and less frequent alcohol intake were associated with higher levels of multimorbidity. Increasing multimorbidity was associated with higher all-cause mortality. Mortality risk was double for those with ≥5 comorbidities compared to those with none. Having cancer, coronary heart disease, diabetes, or chronic obstructive pulmonary disease significantly increased mortality risk. Presence of any cardiometabolic comorbidity significantly increased mortality risk, as did any non-cardiometabolic comorbidity. Conclusions: In stroke survivors, the number of comorbidities may be a more helpful predictor of mortality than type of condition. Stroke guidelines should take greater account of comorbidities, and interventions are needed that improve outcomes for people with multimorbidity and stroke

CHANGES IN LOWER-LIMB MUSCLE FORCES WITH PROPHYLACTIC KNEE BRACING DURING LANDING AND STOP-JUMP TASKS

Prophylactic knee braces are designed to prevent knee injuries, which often occur during sports such as basketball and volleyball, but their efficacy is debated. The purpose of this study is to calculate and compare lower-limb muscle forces in braced and unbraced recreational athletes during landing and stop-jump tasks. Experimental motion capture and ground reaction force data were collected from five participants with and without a knee brace. Subject-specific musculoskeletal models were created in OpenSim and were used to calculate muscle forces. Preliminary results indicated that knee bracing altered both the magnitude and timing of muscle actions. This study provides insight into the likely role of prophylactic knee bracing and muscle function in knee protection