K-State Electronic Theses, Dissertations, and Reports: 2004 -
Permanent URI for this collectionhttps://hdl.handle.net/2097/4
This is the collection for doctoral dissertations and masters theses and reports submitted electronically by K-State students. Electronic submission of doctoral dissertations was required beginning Fall semester 2006. Electronic submission for masters theses and reports was required beginning Fall 2007. The collection also contains some dissertations, theses, and reports from the years 2004 and 2005 that were submitted during a pilot test project. Some items before 2004 have been digitized and are available in K-State Electronic Theses, Dissertations, and Reports: pre-2004. Check the Library catalog for dissertations, theses, and reports not found in these collections.
All items included in this collection have been approved by the K-State Graduate School. More information can be found on the ETDR Information Page. Items within this collection are protected by U.S. Copyright. Copyright on each item is held by the individual author.
Browse
Recent Submissions
Item Open Access Determination of consumer purchase thresholds for discoloration of beef steaks in retail display(2025) Witberler, StephanieThe objective of this study was to evaluate and determine similar purchasing tendencies and develop predictive models for consumer purchase likelihood based on objective measures of steak redness and discoloration to identify thresholds for consumer purchase of beef strip loin steaks. To accomplish this, the study was designed in two phases. Phase 1 required consumers to evaluate steak samples from various days of display ranging in discoloration from fresh to 100% discolored. Phase 2 required consumers to evaluated samples from all the same day of display with similar discoloration. Commercially packaged steaks were procured from a major beef processor in a case-ready format, identical to packages that would otherwise be displayed and sold at retail. Steaks were all the same USDA quality grade (upper 2/3 Choice), and were packaged and stored identically prior to the simulated retail display period. For each phase, steaks were removed from their mother-bag and placed in coffin-style retail cases and displayed under florescent lights for the pre-planned display period (0 – 14 days) in order to create differences in both steak color and discoloration. Consumers (N = 200 phase 1; 176 phase 2) evaluated steaks for overall appearance liking and identified whether or not they would purchase the product (yes/no) if it was fully-priced as well as if it was sold at a discount. Additionally, numerous objective color measures (L*, a*, b*, chroma, hue angle) were assessed on each sample and each was evaluated by a trained descriptive sensory panel for overall redness, % discoloration, and fat color. Results showed that in both phases of the study, all of the objective measures evaluated were predictors (P < 0.05) of consumer purchase intent. The predictive models accounted for 30 – 78% of the variation in consumer purchase intent for steaks sold at full-price and 27 – 72% of the variation when sold at a discount for Phase 1. In Phase 2, the models were less predictive, with models only accounting for 11 – 57% of the variation in consumer purchase likelihood in both full-priced and discounted samples. a* value and trained sensory panel discoloration scores were some of the best predictors evaluated. These models showed that even minimal discoloration has a large impact on consumer purchasing likelihood, with steaks that have 12 to 22 percent discoloration only having a 50% chance of being purchased at full-price. These results underscore the importance of insuring steaks sold at retail are maintained at a bright red level and free of discoloration, with the developed models proving some guidance to the requirements expected by consumers for purchase of beef steaks related to color characteristics.Item Open Access Describing post-mortem characteristics of bovine congestive heart failure and evaluating variability of ionophore concentrations in feed delivered to feedyard cattle(2025) Long, KatieBovine congestive heart disease (CHF) has garnered the attention of both veterinarians and beef cattle producers, raising concerns regarding animal health, welfare, and economics. The exact cause of non-infectious right-sided CHF is not well known. Published data suggest a variety of factors such as genetics, concurrent pulmonary diseases, and other demographics play a role in the onset of CHF. To further complicate matters, CHF clinical case definition varies among feedyards, leading to potential misclassifications. Progressive right-ventricular remodeling leading to cardiomegaly, is a hallmark of CHF. Cardiac eccentric hypertrophy occurs following increased pre-load volume, leading to a dilated ventricle, increased myocardial mass, and increased end-diastolic volume. These anatomical changes result in decreased cardiopulmonary functionality. The objective of this research was to refine bovine right-sided CHF diagnosis and improve post-mortem diagnostic approaches utilizing objective methods in combination with subjective methods, as well as evaluate variability of ionophore concentrations in feed. This thesis delves into associations of objective and subjective post-mortem heart evaluations with the presence of CHF. Digital photographs and CHF diagnoses were acquired from an observational cross-sectional study on feedyard cattle mortalities. Digital cardiac photographs were measured in several locations to determine potential changes in heart size. Systemic post-mortem evaluations of 346 feedyard mortalities resulted in 106 cases being classified with cardiac enlargement/misshapen ventricle (CEMV). The CEMV cases were determined based on gross evaluation of heart size and shape with no signs of infectious heart disease present. A subset of CEMV cases were determined to be CHF when cases included congested (nutmeg) liver and at least two of the following lesions: serous or serosanguineous pleural, peritoneal, or pericardial effusion. Eleven of the 346 mortalities were classified as CHF. Descriptive statistics and multivariate models were used to identify associations between objective heart measurements and subjective heart scores with the prevalence of CEMV or CHF. The CEMV model showed heart width, left ventricular thickness, and right ventricular lumen area significantly associated with the prevalence of CEMV cases (p<0.05). Heart scores were also associated with the prevalence of CEMV cases (p<0.01). In contrast, identifying associations between CHF and objective heart measurements and subjective heart was not possible because the CHF model did not converge. Heart measurements and scores can be used to improve diagnosis of heart disease post-mortem and provide further insight into subclinical heart disease. An additional retrospective case-control study was conducted to determine potential differences in cardiac and hepatic histopathology between CHF cases and feedyard mortalities from other causes. Post-mortem examination was performed and samples retrieved from animals with grossly abnormal and normal hearts. Case-definition for CHF included abnormal heart shape, congested liver, and presences of ancillary signs; all other cases were considered as non-CHF for comparison. Cardiac and hepatic histopathology was performed categorizing fibrosis and necrosis into either none/minimal or moderate/severe changes. A generalized linear model was used to evaluate potential associations between the probability of CHF with histopathological lesions. Of the 87 cases included for analysis, 11 met the case definition for CHF. Cardiac histopathologic changes were identified in grossly normal and abnormal hearts with moderate/severe necrosis in 14.9% of mortalities and 16.1% moderate/severe fibrosis of mortalities. Hepatic necrosis was moderate/severe in 33.3% of mortalities and hepatic fibrosis was moderate/severe in 16.1% of mortalities. Liver fibrosis was the only factor associated with CHF probability and cattle with moderate/severe liver fibrosis were more (P < 0.01) likely (0.57 +/- 0.13) to have CHF compared to cattle with minimal liver fibrosis (0.04 +/- 0.02). These results illustrate cardiac histopathologic changes were relatively rare and not associated with the probability of abnormal heart shape; however, hepatic histopathology may be useful in confirming CHF. This thesis further investigated potential external contributors to CHF in cattle, such as the potential role of ionophore toxicosis. Ionophores are a class of antibiotics commonly added to feed in commercial cattle feeding operations to act as a coccidiostat and increase feed efficiency. In high concentrations, ionophores can cause acute cardiotoxic effects in cattle, resulting in clinical signs similar to CHF. The first objective of this study was to evaluate the differences in the mean and variation of monensin concentrations between bunk location (at-delivery and 2 hours post-delivery), and between the batch location (beginning and end of batch as delivered from feed truck) to evaluate finisher ration samples from feedyards. One truck load was considered a batch and consisted of four feed samples (A, B, C, and D) from one central Kansas feedyard on eight different days. Sample points A and B were collected from the feed bunk at the initial time of feed delivery from the point where the truck began unloading (A) and where the truck finished unloading (B). Sample points C and D were collected from the same feed bunk 2 hours after-delivery from the point where the truck began unloading (C) and where the truck finished unloading (D). The second objective was to evaluate associations of feedyard diet particle size with monensin concentrations. Particle size distribution of starter and finisher ration samples were determined using a Penn State particle separator with four sieves (S1 = 0.75, S2 = 0.31, S3 = 0.16, S4 = <0.16). All samples were analyzed for monensin concentrations using Ultra Performance Liquid Chromatography (UPLC). Descriptive statistics were conducted on monensin concentrations and variability between samples and two multivariate models were used to identify associations between monensin concentrations in 1) batch or bunk location and 2) sieve location or ration type. There was no interaction between delivery timing and start or end of the batch; however, batch location affected monensin concentration in that the start of the batch had a higher (32,934 ± 18,982; mean ± SD) monensin concentration compared to the end of the batch (28,185 ± 17,560). In the second model, there was an interaction between sieve and ration type (P<0.01). The monensin concentrations in both starter (7,122 ± 3,477) and finisher (9,638 ± 4,705) rations were lower in S1. The monensin concentrations in both starter (25,837 ± 12,613) and finisher (18,384 ± 8,975) rations were highest in S4. These results show that monensin concentrations in feed samples can have important variability. These projects demonstrated the utility of objective heart measurements, subjective scoring systems, and liver histopathology in further refining the bovine right-sided CHF definition for feedlot cattle. Utilizing gross pathological findings, histopathologic findings, and monensin concentration variability, these useful approaches provide data that help fill the information gaps related to bovine right-sided CHF. This work warrants further research and lays a foundation for future hypotheses like evaluating objective post-mortem diagnosis and identification of risk factors for CHF.Item Open Access Measuring up: Testing measurement equivalence and developing a concise organizational transparency scale(2025) Stuckey, LeahThe current study had two aims, the first was to test the measurement equivalence (ME) of an organizational transparency scale, and the second aim was to develop a shorter organizational transparency scale. For the first aim, multi-group confirmatory factor analysis and item response theory (IRT) methods were used to investigate two research questions regarding the potential ME of the organizational transparency scale between public and private sector employees as well as employees who belong to one of two different government agencies in the same facility within the public sector. The results found evidence in support of ME in both cases of the private vs. public sector comparison and between the two agencies within the private sector, although the latter did have differential item functioning for one item. The ME results provide evidence for the benefits of utilizing both factor and item level analyses to capture a fuller picture and provide more nuanced information. For the second aim, IRT was used to develop a more concise organizational transparency scale. The developed shortened scale was made up of eight items and demonstrated validity and reliability. The newly shortened scale will hopefully aide in spurring more research on organizational transparency and in turn further develop its nomological network as researchers and practitioners alike will now be able to incorporate it more easily into their surveys with the reduction in survey length compared to the original 23-item scale and they can balance it with considerations of compensation costs, total survey length in conjunction with other constructs, participant experience, etc. With these two lines of research, the study findings have the potential to stimulate more research on the construct of organizational transparency with knowledge on the generalizability of the scale across industry sectors and within the public sector as well as through the creation of the shortened scale which provides benefits to survey participants, researchers, and practitioners.Item Open Access Cattle feeding in the Great Plains: Economic and environmental impacts of cattle performance and disease management(2025) Day, MerriThe United States Roundtable for Sustainable Beef (USRSB) is credited with developing a framework that provides specific targets for achieving sustainability throughout all sectors of the U.S. beef industry. Livestock operations have been identified as important contributors to greenhouse gas emissions, and the U.S. beef industry is under considerable pressure to reduce its environmental footprint, specifically within the feedyard sector. The USRSB aims to reduce feedyard greenhouse gas emissions by 10% per pound of beef produced by 2030. The USRSB also identifies animal health and well-being, which includes assurance of proper veterinary care, as a top priority for beef feedyards. In beef cattle feedyards, challenges related to animal health and disease management are compounded by space and density, and even the most treatable illnesses can have considerable harmful effects on both herd health and economic returns. Innovations in feeding technologies such as growth implants and feed additives have shown potential for reducing greenhouse gas emissions. Advancements in veterinary diagnostics and use of antimicrobials have proven effective in improving outcomes for diseased cattle in feedyards. However, economic viability of these management practices is paramount to achieving feedyard sustainability goals set forth by the USRSB. The first study examines how alternative cattle feeding management decisions impact both net returns and greenhouse gas emissions. We use established procedures to estimate the effects of changes in mortality and growth implant protocols on feedyard net returns. We then propose new methods for estimating concurrent impacts to feedyard greenhouse gas emissions. Using operational feeding data, we find that reducing mortality consistently increases net returns while reducing greenhouse gas emissions intensity. Additionally, our findings indicate that using two growth implants compared to one has potential for simultaneous improvement of both net returns and greenhouse gas emissions intensity. The second study estimates net returns from feedyard cattle identified with acute interstitial pneumonia (AIP) ante-mortem and post-mortem. A decision tree framework is implemented to estimate net returns for cattle that finished with their cohort, were culled, or died following an AIP diagnosis. Using comprehensive data, we find that economic outcomes vary across sex, placement weight, and number of AIP treatments. Findings generally indicate that expected returns from treating cattle identified with AIP are favorable to estimated returns from culling. The third study examines predictors of terminal outcomes for feedyard cattle diagnosed with AIP ante-mortem. Using comprehensive data, mixed-effects logistic models are employed to estimate the probabilities of first AIP treatment failure and failure to finish for cattle treated at least once for AIP. Findings from this analysis indicated that sex, weight, AIP treatment timing, and prior bovine respiratory disease treatment were significantly associated with the probability of first AIP treatment failure and probability of failure to finish. Building upon findings from the second and third studies, we develop a spreadsheet-based decision aid to support the management of feedyard cattle identified with AIP. Following methods described in the second study, the decision aid prepares a comparison of expected returns from treating an animal compared with estimated returns to culling the animal without AIP treatment, along with probabilities of AIP treatment outcomes as described in the third study.Item Embargo The ability of abdominal ultrasound to identify gastrointestinal foreign body characteristics prior to attempted laparoscopic-assisted gastrointestinal foreign body removal.(2025) Toth, DarbyObjective: To determine the accuracy of abdominal ultrasound (AUS) in determining gastrointestinal foreign body obstruction (GIFB) type, location, size and shape; and to determine the success rate of laparoscopic-assisted GIFB removal (LGFBR) with GIFB of various sizes, shapes, and locations. Study Design: Prospective clinical study. Animals: Client-owned dogs (30) that underwent LGFBR (31). Methods: Dogs with known or suspected GIFB obstruction underwent a preoperative AUS performed by a board-certified radiologist. GIFB type, location within the gastrointestinal tract, size, and shape were recorded, as well as the presence or absence of peritoneal fluid, pneumoperitoneum, or gastrointestinal mural changes. LGFBR was then attempted in all patients. Surgical findings were compared to preoperative ultrasound findings. Results: AUS was able to determine the type, location, and shape of GIFB with accuracies of 96.8%, 74.2%, and 93.5% respectively. AUS had moderate accuracy (80%), at identifying the presence of adhesions, and was inaccurate at determining GIFB size. LGFBR was successful in 16/30 (53.3%) of cases, including 2/7 (28.6%) of linear, 14/23 (60.9%) non-linear, and 1/1 (100%) gastric foreign bodies, but was not successful for GIFB near the caudal duodenal flexure (0/2, 0%). Conclusion: Preoperative AUS is a useful diagnostic to aid in determining the suitability of a patient to undergo LGFBR. Linear and gastric foreign bodies were not contraindications to LGFBR, however GIFB located at the caudal duodenal flexure were. Clinical Significance: Based on our study, AUS would be recommended prior to attempting LGFBR. Further studies are recommended to investigate contraindications to LGFBR.Item Open Access A fresh look at ground beef spoilage(2025) Frink, LaurenThe objective of this study was to determine the point at which ground beef reaches spoilage as determined by consumers relative to microbiological, lipid oxidation, color measurements, and the meat microbiome. Retail ground beef packages were delivered to the KSU meat laboratory from a case-ready facility and randomly assigned to a display duration (0 – 14 d). Packages were stored in mother-bags at 2 – 4°C in the absence of light until placed in coffin-style retail cases under fluorescent lighting conditions at 2 – 4°C for 8 different display periods. Consumer sensory analysis of visual, odor, touch, and taste were compared to objective measurements of trained sensory redness scores, discoloration scores, microbiological, lipid oxidation, and meat microbiome analysis. For each organoleptic measurement, consumers were asked if they would purchase the sample, and whether or not they thought the sample was spoiled. Consumers were less (P < 0.05) likely to purchase and more (P < 0.05) likely to rate samples as spoiled based on visual, touch, and odor evaluation once they reached 8 d of display. Logistic regression models were generated and indicated appearance measurements were the strongest predictors of consumers likeliness to purchase, and spoilage assessment. Threshold values of 50, 75, 90, and 95% were identified for consumer purchase intent, and values of 5, 10, 25, and 50% were identified for consumer spoilage indication. Objective measurements such as trained sensory panel redness score also served as very strong (P < 0.05) predictors, explaining 86% of the variation within the consumer purchase intent model with redness scores of 74.8, 64.1, 48.4, and 32.7 corresponding to 50, 75, 90, and 95% purchase likelihood. 77% of the variation within the consumer appearance spoilage rating model was explained by trained sensory redness score, with 74.75, 64.10, 48.40, and 32.7 corresponding to 5, 10, 25, and 50% likelihood of a consumer rating a sample as spoiled. While there are relationships present between the consumer purchase intent and spoilage rating and other quality measures, the purchase intent and spoilage decision of the consumers was mostly driven by the color and appearance of the sample in the retail case.Item Open Access Phenomenological research on the motivation and self-directedness of recreational motocross athletes returning to the sport after significant injury(2025) Young, DarynParticipation in recreational extreme sports is on the rise, but with extreme sport participation comes significant injuries. Recreational extreme athletes endure a variety of significant injuries that hinder their normal function and sometimes cause permanent, life-altering trauma. Due to the individualistic and recreational nature of these extreme sports, the athletes involved do not participate for monetary reasons, career aspirations, or the pursuit of fame. It is unclear what motivation and self-directedness these athletes experience when returning to their recreational extreme sport after sustaining a significant injury. This study used a hermeneutic phenomenological framework to analyze the motivation and self-directedness of recreational motocross athletes who continue their participation after sustaining a significant injury in recreational motocross. Self-determination theory and self-directed learning theory guided the research. To maintain consistency in participant selection and phenomenon experienced, a part of the selection criteria is participation in recreational motocross. Participants had sustained a significant injury through their participation in the sport, and continued their participation once rehabilitated. Data were collected through two semi-structured interviews. This study included six participants. Data from interviews, researcher journaling, and analytic memos were analyzed for emerging patterns and themes using the hermeneutic phenomenological framework. Key findings of motivation and characteristics of self-directedness were found. Several themes emerged and included getting the most out of life, social forces to quit from outside the sport, friendship and camaraderie, feelings of accomplishment, special intrinsic sensation, desire to have fun, responsibility for injury and rehabilitation, sought information, fearful of reinjury, why do I want to keep doing this, and changing their strategies within the sport.Item Open Access Generalizing the Chevalley-Warning Theorem(2025) Collins, LailahThe Chevalley-Warning Theorem states that a set of polynomials over a finite field without constant terms has a non-trivial common zero if the number of variables exceeds the sum of the degrees. In this report, we will prove the Chevalley-Warning Theorem along with one of its generalizations. This will be done by using the Combinatorial Nullstellensatz.Item Open Access The impact of rising interest rates on farm profitability and debt management strategies(2025) Freund, AlexisThe agricultural sector depends on external financing, making it vulnerable to interest rate changes. This study examines the impact of rising interest rates on capital debt repayment capacity (CDRC) and default probability using Kansas Farm Management Association (KFMA) data. Sensitivity analysis reveals that while higher rates increase repayment costs, default risk is primarily driven by owner equity (OE) and working capital (WC). Farms with OE below 60% faced default probabilities exceeding 0.50%, while those above 80% had near-zero risk. A 50% reduction in WC significantly increased default probability, highlighting liquidity’s role in financial stability. Beyond financial metrics, lender-borrower relationships, risk management tools, and refinancing options influence farm financial resilience. Findings suggest that equity accumulation, liquidity preservation, and revenue diversification mitigate financial risk more effectively than focusing on interest rates alone. Policy interventions supporting credit access and debt restructuring may enhance financial stability. Future research should explore long-term refinancing risks, farm profitability under prolonged high-interest environments, and the effectiveness of financial education programs in improving borrower resilience. Additionally, the role of technological adoption in cost management and its potential to offset rising borrowing costs warrants further analysis. Understanding these dynamics can help lenders and policymakers implement targeted financial support mechanisms, ensuring the sustainability of agricultural operations in fluctuating economic conditions.Item Open Access Skeletal and respiratory muscle oxygen transport in pulmonary hypertension(2025) Schulze, KianaPulmonary hypertension (PH) is a disease characterized by pulmonary vascular remodeling and elevated pulmonary arterial pressures which subsequently impairs gas exchange in the lungs and eventually, right ventricular function. Hallmarks of PH include dyspnea and exercise intolerance which, despite previous notions, is not solely attributable to cardiopulmonary dysfunction. In these investigations, we sought to determine whether skeletal and respiratory muscle blood flow and vascular function are impaired in PH at rest and during contractions or exercise. Specifically, we used intravital microscopy, fluorescent microspheres, and pressure myography to explore these questions in a monocrotaline rat model of PH. Our findings demonstrate that resting and exercising blood flow and oxygen transport are lower in skeletal muscle via convective and diffusive impairments in PH compared with healthy controls. In respiratory muscle (i.e., the diaphragm), PH rats display a regional redistribution toward the ventral and crural regions of the diaphragm during contractions and submaximal exercise. These regions are not expected to contribute as greatly to ventilatory work and this observation therefore unveils a mechanism potentially underlying diaphragmatic weakness and failure in PH. Our findings suggest that the medial costal diaphragm arterioles are less reactive, both to vasodilatory stimuli as well as changes in intraluminal pressure, which may help explain the basis for this regional redistribution. Finally, we’ve found that there is a heightened diaphragm blood flow during submaximal exercise in PH compared with healthy animals that is concurrent with a lower skeletal muscle blood flow. This redistribution of blood flow toward the diaphragm and away from working muscle during exercise is likely related to diaphragm vascular dysfunction and exercise intolerance. As such, these derangements may provide a specific target for therapeutic interventions that could potentially normalize muscle blood flow distribution to that of healthy individuals and help ameliorate exercise intolerance. This body of work provides novel insights into skeletal and respiratory muscle oxygen delivery alterations at rest and during exercise in PH, providing evidence for oxygen transport-related mechanisms that may predicate both dyspnea and exercise intolerance in PH. Future directions will hopefully assess targeted therapeutic strategies aimed at improving diaphragm vascular function with the goal of restoring blood flow and oxygen delivery, improving O2 delivery-to-O2 demand matching and improving the quality of life and prognosis in PH.Item Open Access A demographic exploration of implicit racial bias and perceptions among faculty and students in a California community college(2025) Black, AmberThis study explored implicit racial bias in a community college setting by examining whether racial identity and perceptions about racial bias among faculty and students intersect. The researcher examined one Hispanic-serving institution (HSI) as literature suggested a need for data from this demographic. This quantitative study included qualitative data addressing two research questions: What significant associations exist between the racial identification of faculty and that of their students in relation to final grading outcomes? How do faculty and student perceptions regarding faculty racial bias toward students differ? The Pygmalion effect and critical race theory (CRT) were the guiding frameworks that directed this research. CRT and the Pygmalion effect provided lenses through which this study’s research questions and methodology were constructed, and how data collection, findings, and analyses were discussed. These theories addressed unconscious and racial biases related to teachers’ and students’ perceptions. The main findings revealed students perceived less implicit racial bias, microaggressions, and racism than faculty, but full-time faculty perceived more of the former than part-time faculty did. Non-White faculty and White students reported more perceived issues with race than White faculty and non-White students. Faculty and students reported possible anti-White sentiments on campus, and the majority of faculty participants shared they had never taken an implicit racial bias test. These conclusions reveal as higher education institutions continue developing antiracist policies, faculty must continually strive to better understand other faculty, their students, and how diverse needs could best be met. Keywords: Race, racial identification, implicit racial bias, grading outcomes, pygmalion effect, Hispanic serving institution, faculty, students, perceptions, critical race theory (CRT)Item Open Access Evaluation of indwelling pH monitoring technologies and growing strategies for beef cattle(2025) Weir, ColtonA series of experiments were conducted to evaluate different technologies currently utilized within the cattle industry to continuously and remotely measure ruminal pH, limit-feeding high energy rations on newly received cattle performance and digestion. Subacute ruminal acidosis (SARA) is the predominant digestive disorder affecting feedlot cattle. Despite the prevalence and economic loss, there is still debate about the exact timing, pH range, and time spend under that curve that induces SARA. Historically, measuring ruminal pH has been conducted through digesta samples via cannulation, stomach tube, or aspiration of the ventral sac. A disadvantage to all these methods is the invasiveness and disruption of normal cattle behavior to collect samples. Therefore, in Exp 1. we evaluated two different indwelling monitoring boli that continuously measure ruminal pH. We compared using smaXtec boli (SMAX; smaXtec Inc., Graz, Austria), Moonsyst boli (MOON; Moonsyst International, Kinsale, Republic of Ireland), and a handheld pH meter (METER; PH8500 pH/mV Meter, Apera, Columbus, OH) over 126 d in vivo, ex vivo in known standards, and during an ex vivo acidosis challenge. Eight ruminally cannulated crossbred heifers were utilized in a complete randomized design through 6-consecutive 21-d periods. Ruminal pH measurements obtained from MOON were lesser (P ≤ 0.01) than METER in every period. As time progressed the difference between the two became larger ∼ 84 to 126 d (treatment × period, P < 0.01). Conversely, measurements of pH with SMAX were greater (P < 0.01) than METER from periods 1 to 3 and 6. In a known pH standard of 7, MOON again yielded measurements lesser than 7 and SMAX yield measurements greater 7 (treatment × period, P < 0.01). However, in a standard at lower pH of 4, MOON and SMAX measurements were not different (P ≥ 0.13) from pH 4 until period 6 (treatment × period, P = 0.02). During the acidosis challenge, the degree of change in pH before and after the addition of vinegar was measured using MOON, SMAX, and METER. The change in pH obtained using METER was considered the true change in pH. MOON yielded measurements similar (P = 0.36) to METER while SMAX measurements were greater (P < 0.01) compared with METER. In Exp 2. we evaluated the effects of increasing dietary energy while restricting intake on growth performance, digestion, and fermentation characteristics in growing beef heifers. In Exp 2.a 70-day growing study was conducted to determine the effects of energy concentration and dry matter intake on growth performance, digestion and fermentation characteristics of newly received growing beef cattle. A total of 392 crossbred heifers (initial bodyweight = 274 ± 26 kg). Heifers were blocked by weight (4) and assigned to 12-13 head pens; pens were randomly assigned to 1 of 4 dietary treatments. Experimental treatments included a high-roughage diet fed for ad libitum intake (AL) or a limit-fed high-energy diet fed at 75% (LIM75), LIM80 (80), or 85% (LIM85) of AL intake within block. Treatments were designed to equalize energy intake between calves assigned to AL and LIM75. In Exp 3, eight ruminally cannulated, crossbred heifers were utilized in a 4 × 4 Latin square to determine digestibility and ruminal fermentation characteristics of the diets from Exp. 2. Heifers were utilized in four consecutive 15-d periods. Final BW and ADG were similar (P = 0.37) between AL and LIM75, and greater (P ≤ 0.05) in LIM80 and LIM85 compared with AL. By design, dry matter intake was greater (P ≤ 0.01) in AL heifers compared to all 3 limit fed treatments. As a results feed conversion was improved by 30% (P ≤ 0.01) in limit fed heifers compared with AL and did not differ (P ≥ 0.20) among LIM75, LIM80, or LIM85. Dry matter digestibility was 10%, 5%, and 4% greater in among LIM75, LIM80, and LIM85, respectively, compared with AL. Organic matter, neutral fiber, and acid fiber digestibility were also greater in limit-fed treatments compared to AL. A treatment × hour interaction (P < 0.01) was observed for ruminal pH. Limit fed calves reached pH nadir earlier compared with AL with LIM75 being lowest, LIM80 intermediate, and LIM85 being greatest. Total ruminal VFA concentrations were unaffected by treatment (P = 0.34); however, there was a tendency (P = 0.08) for propionate concentrations to be intermediate and greater in LIM80 and LIM85 heifers, respectively, compared with AL and LIM75. Ruminal ammonia concentrations were greater (P < 0.01) in AL compared to limit fed treatments and experienced three different peak concentrations 2, 8, and 18 h post feeding compared with limit fed treatments singular peak 2 h post feeding (treatment × hour; P < 0.01). Based on our data in Exp 1, there is still variation in pH measured obtained via indwelling pH boli. Both MOON and SMAX experienced drift over time, however, during a simulated acidosis challenge MOON detected changes in pH similar to METER. Conversely, ruminal pH measurements over a 24 h period using SMAX were more closely related to METER. Based on results in EXP 2 and 3, limit feeding higher energy diets that include corn coproducts does not negatively influence growth performance or fermentation products. Subsequently, limit feeding improved total-tract digestibility and feed efficiency compared to a traditional receiving ration.Item Open Access Teacher attrition in the midst of geographical, societal, and economic realities: Insights from fifteen years of the Kansas teacher workforce(2025) Lam, Chanh BaoLeveraging longitudinal administrative data from Kansas, a state with a unique mixture of urban and rural dynamics, I examine mobility patterns of the state’s public-school teachers from 2010 through 2024. I find teacher attrition has sharply increased since the COVID-19 pandemic, especially by those who resigned from the state’s public elementary and secondary school system (i.e., leavers). I also find teachers employed in city schools are more likely to depart from the state’s school system relative to their colleagues in suburban and rural/town schools, even after accounting for the relative urbanicity of the district’s local community. Moreover, teachers serving the most marginalized and impoverished students are at the highest risks of turning over. Furthermore, STEM and SPED/ESOL teachers are significantly more likely to turn over relative to their counterparts in other subject categories. Notably, while salary and benefits are significantly associated with reductions in teacher turnover across teaching disciplines, the relationship is most pronounced among STEM and SPED/ESOL educators. These findings reflect the complex geographical, societal, and economic circumstances of Kansas, offering critical insights to targeted policy considerations for addressing the state’s teacher staffing challenges. I discuss the needs for Kansas to diversify its teacher workforce, addressing potential disparities among teacher working conditions, including among schools within the same district, as well as the potential of differential pay policies for Kansas educators amid the state’s chronic teacher shortages and changing labor markets in the post-COVID-19 era.Item Open Access Assessment of cool-season turfgrass sod production characteristics of tall fescue and Kentucky bluegrass(2025) Nwachukwu, EmmanuelThe demand of high quality turfgrass cool-season sod is increasing in the transition and northern climatic zones of the United States. Genetic variation exists among Kentucky bluegrass (Poa pratensis L.) (KB) cultivars and tall fescue (Festuca arundinacea Schreb.) (TF) is gaining popularity to be used for sod, but the bunch type growth habit creates a limitation. My objectives in Chapter 2 were to: 1) quantify the influence of nine KB cultivars of varying classifications mixed with TF in a 95:5 (w/w) mixture ratios; and 2) quantify the influence of three KB cultivars of varying growth aggressiveness levels mixed in varying TF:KB mixtures of 97:3, 95:5, and 90:10 (w/w); on sod strength, ecological dynamics, and establishment vigor. My objectives in Chapter 3 and 4 were to quantify the speed of germination, establishment vigor, rhizome characteristics, as well as sod strength and handling of KB classifications (Shamrock, Compact, Jefferson etc.) and seven rhizomatous tall fescue (RTF) cultivars, respectively. In Chapter 2, results revealed KB classifications or growth aggressiveness level in sod varying ratios (90:10, 95:5, or 97:3 TF:KB w/w) produced similar-to-no differences in sod strength and handling across multiple harvests (12.1 – 15.9 N-m). There was more tendency for a 90:10 or 95:5 (TF:KB w/w) sod mixtures to have higher sod strength than 100% TF sod. In Chapter 3, there were differences in sod strength among KB cultivars (~22 to 38 N-m, required work to tear; 389 to 568 N of maximum tensile load to tear sod), rhizome characteristics (rhizome number, length etc.) and germination and establishment vigor. Kentucky bluegrass classifications was not a good indicator for cultivar selection. In Chapter 4, RTF monostands did not produce similar high sod strength compared to 100% KB sod. Short rhizome lengths (<5 mm) were observed in RTF compared to >70 mm for KB. Differences were observed in germination (5 – 10 d) and establishment vigor (10 – 15 d) of RTF when compared to KB.Item Open Access How & why?: Third-person perceptions of people with terminal illnesses’ suicides as a function of suicide method & motive(2025) Schiffer, AshleySuicide and terminal illness are two phenomena that are stigmatized independently of one another (e.g., Batterham et al., 2013; Epley & McCaghy, 1978). However, suicide by people with severe physical health states is perceived fairly positively in general (e.g., Schiffer & Saucier, 2024) as well as more acceptable compared to suicides precipitated by other situations (e.g., interpersonal issues; Winterrowd et al., 2015). For further insight on the coexistence of suicide and terminal illness, this research quantitatively assessed how third-person perceptions of people with terminal illnesses’ suicides (e.g., acceptability, stigma) vary as a function of situational factors related to the suicide as well as individual differences among participants related to pride and existential considerations. Vignettes were used in between-groups designs to manipulate situational factors including a target person’s suicide method (Study 1) and primary motive (Study 2). On average, participants reported generally favorable attitudes toward this phenomenon across studies. In Study 1, medical methods (e.g., physician-assisted death) were perceived more favorably than traditional methods (e.g., hanging), but minimal differences in perceptions emerged across various suicide motives (e.g., mental health concerns, wanting control over death) in Study 2. Masculine Honor Beliefs were positively associated with stigmatizing attitudes toward the target. The effects of Free Will Beliefs were often moderated by the conditional manipulations. Self-directed and other-directed Fear of Death yielded contradictory effects. Suicide Acceptability was consistently positively associated with favorable attitudes toward this phenomenon. Overall, this program of research has important implications for understanding nuances in third-person perceptions of this phenomenon as a function of relevant situational factors (e.g., method, motive) and individual differences, while advancing suicide theories to be more comprehensive and inclusive of severe physical health states.Item Embargo Evaluation of women’s perceived safety after dark using VR (Virtual Reality) technology(2025) Kazemidemneh, MaryamThe development of public lighting has changed the appearance of cities and opened opportunities to extend daily activities into the night. The quality and quantity of lighting has a significant impact on people's participation in nighttime activities, and in particular, their sense of safety and security in public areas such as streets and sidewalks. This research looks at how lighting design can increase the perception of safety for women. This study investigated the effect of certain types of lighting design on women’s perceived safety after dark in an outdoor urban environment, using virtual reality (VR) technology. Eight distinct lighting scenarios were created, which included variations in lighting height (bollard and pole), color temperature (warm and cool), and façade lighting (upper and lower). A within-subject experimental design was employed, where each participant experienced all lighting scenarios. The experiment was divided into two separate 2x2 factorial design studies. The first experiment explored the effect of color temperature and lighting height on perceived safety, with participants experiencing four scenarios that combined warm and cool color temperatures with bollard and pole lighting. The second experiment introduced upper and lower façade lighting and its effect when paired with bollard and pole lighting. The simulated site was a representation of a residential street in a medium-sized city in the United States. Fifty female volunteers were recruited to participate in the study. Each participant wore a VR headset and after virtually walking through the eight lighting scenarios, they rated their perceived safety using a Likert scale. After collecting the data, statistical analyses, including ANOVA and post-hoc tests, were performed to assess the main and interaction effects of lighting type, color temperature, and façade lighting on women’s perceived safety. The main effects examined how each factor—color temperature, lighting height, and façade lighting—individually influenced perceived safety. The interaction effects, on the other hand, examined whether the combination of these factors produced a different impact on perceived safety, indicating how the effect of one factor might change depending on the level of another. In the first experiment, the results indicated that participants felt safer in scenarios with bollard lighting, and combining bollard lighting with pole lighting significantly enhanced their perceived safety. However, t-test calculations showed that the effect of color temperature on perceived safety was not statistically significant, and the ANOVA test results revealed no significant interaction effect between lighting height and color temperature, indicating that the influence of lighting height on perceived safety was not dependent on the color temperature. The second experiment showed that lighting height and façade lighting had a significant main effect on perceived safety. Façade lighting on the lower part of buildings made participants feel safer compared to upper façade lighting, and similar to the first experiment, bollard lighting when combined with pole lighting, significantly increased perceived safety. However, the ANOVA test did not reveal any significant interaction effect between lighting height and façade lighting, indicating that the influence of lighting height on perceived safety was independent of the type of façade lighting, and vice versa. The results of this study provide valuable insights into the effectiveness of various lighting design strategies for enhancing women’s perceived safety in urban environments after dark. Policymakers, including organizations such as the Illuminating Engineering Society (IES), the International Dark-Sky Association (IDA), the U.S. Department of Energy (DOE), transportation planners, and public works staff can utilize this information to develop regulations and guidelines to promote effective lighting solutions that will enhance perceived safety, which can lead to increased walkability in urban areas, contributing to the vibrancy of public spaces. In addition to policymakers and organizations, the findings of this study are equally beneficial for architects, urban designers, and lighting professionals. These practitioners can integrate insights into their design processes to create urban spaces that prioritize safety. Architects, in particular, can apply these results to design buildings with exterior elements that thoughtfully incorporate lighting, enhancing both the architectural aesthetic and the overall sense of safety in the surrounding environment. This research shows that thoughtful lighting design can significantly influence human health and well-being by fostering a sense of security that encourages individuals to engage in outdoor activities, ultimately creating healthier, more active communities.Item Embargo Characterizing the mechanism of action of the Legionella pneumophila effector LegC4(2025) Brucken, TshegofatsoLegionella pneumophila, a facultative intracellular bacterium, can cause Legionnaires’ disease in vulnerable populations by exploiting alveolar macrophages for replication. Among its arsenal of over 300 Dot/Icm-translocated effector proteins, LegC4 has emerged as a unique effector, playing a critical role in promoting bacterial fitness in protozoan hosts while paradoxically restricting bacterial replication in cytokine-activated macrophages and in the mouse lung. The focus of this dissertation was on characterizing the mechanisms of action of the effector LegC4 and its interactions with host processes and immune defenses, with the goal of uncovering novel innate immune strategies and identifying key targets of bacterial virulence factors. Previous studies established that LegC4 enhances cytokine-mediated restriction of L. pneumophila in macrophages and in vivo, highlighting its involvement in key immune pathways. Building on this foundation, I sought to investigate the mechanisms by which LegC4 contributes to host defense against L. pneumophila. We found that bacteria expressing legC4 are targeted to lysosomes in a cytokine-dependent manner. Additionally, our work identified host proteasome activator (PA) 28α as a key target of LegC4. The PA28αβ complex facilitates the degradation of oxidant-damaged proteins during inflammation and oxidative stress. We found that in macrophages and mice lacking PA28αβ (Psme1/2-/-), LegC4-mediated restriction is abolished. Furthermore, we show that in the presence of LegC4, there is increased accumulation of oxidant-damaged proteins, and oxidative stress is sufficient to restrict bacterial replication. Given the targeting of legC4-expressing bacteria to lysosomes, we explored upstream mechanisms, focusing on the role of autophagy, a key cell-autonomous defense mechanism, in LegC4-mediated restriction. Our findings reveal that autophagy is essential for this process, as pharmacological inhibition of autophagy rescues bacterial replication of legC4-expressing bacteria. Moreover, we found that LegC4 enhances autophagy as shown by increased LC3 lipidation and autophagosome formation. Additionally, under oxidative stress conditions, LegC4 further enhances autophagic activity, emphasizing its role in promoting this crucial host defense strategy. In summary, this work provides novel insights into how LegC4 modulates bacterial fitness and effector-driven host immune responses to bolster host defenses. These findings contribute to the growing recognition of effector-triggered immunity as a component of innate defense mechanisms in metazoans. Notably, this study identifies a novel role for PA28αβ in cell-autonomous immunity, demonstrating its contribution to host defenses against L. pneumophila. Overall, this research highlights the complex strategies employed by mammalian hosts to defend against intracellular pathogens and suggests new avenues for therapeutic interventions. Specifically, the potential of using bacterial effectors, like LegC4, as tools to enhance innate immune responses or modulate immune functions to target and inhibit intracellular pathogens.Item Open Access High-amylase corn hybrid in beef cattle diets and in high-moisture corn, and nutritive value of wet-milling corn by-products(2025) de Souza Monteiro, LudmilaA genetically modified corn hybrid with high [alpha]-amylase content was initially developed for the ethanol industry to reduce the need for adding exogenous amylase during fermentation. This hybrid has since gained attention in the animal industry as a promising feed source. The corn ethanol industry also produces by-products that serve as important feed resources for livestock, such as Sweet Bran (SB; Cargill, Blair, NE), a branded wet corn gluten feed. Two studies were done to evaluate the use of a high-amylase corn hybrid (Enogen corn; EC; Syngenta Seeds, LLC, Durham, NC) compared to a conventional corn (CON) as silage (SIL), steam-flaked corn (SFC), and high-moisture corn (HMC). A third study evaluated individual SB components in high-roughage diets. The first study aimed to evaluate growth performance of backgrounding steers as well as their subsequent finishing performance, carcass traits, and liver abscess incidence. Crossbred beef steers (n=912; 306 ± 8 kg initial body weight) were assigned to a randomized complete block design with four backgrounding treatments with two corn silage hybrids (EC-SIL or CON-SIL), and two SFC hybrids (EC-GRA or CON-GRA). During the finishing phase, animals were assigned to one of two grain hybrid treatments (EC-GRA or CON- GRA). There were no three-way interactions for measures of interest, and no differences among treatment combinations with respect to average daily gain (ADG) or incidence of abscessed livers (P > 0.10). During the backgrounding phase, steers fed EC-GRA had lower feed intake (P = 0.04) than CON-GRA, thus leading to improved overall gain:feed (G:F; P < 0.01). And during the finishing phase, overall G:F tended to be greater for cattle fed CON-GRA (P = 0.06). There was a tendency for interaction between GRA fed in the backgrounding and GRA fed in the finishing phase for hot carcass weight (HCW; P = 0.07), such that steers fed the same hybrid in both phases had greater HCW compared to those fed different hybrids in each phase. In the second experiment, fermentation characteristics, aerobic stability, and in vitro ruminal fermentation of HMC from either EC or CON, harvested at three distinct dry matter (DM) levels (66%, 71%, and 74.5%) and four storage lengths (30, 60, 90, or 120 d) were evaluated. In a randomized complete block design HMC was ensiled in 57 L plastic barrels. At d 30, EC 74.5% had the highest pH value (P = 0.07), followed by CON 74.5%. The lactic acid concentration was lowest for EC 74.5%, followed by CON at the same DM level, while the highest concentration was observed for EC 66%, which was similar to CON 66% (P < 0.0001). For yeast and mold count, CON 71% and 74.5% had higher amount at d 90 compared to other treatments, and all treatments by d 120, except EC 74.5%, lowered the count (P = 0.001). The DM was the only variable affecting aerobic stability (P < 0.0001), 66% was the most stable, and 74.5% was the least. Regarding the in vitro fermentation, 74.5% took longer to reach half of maximum gas production than 66% and 71% (P < 0.0001), and d 0 took longer than d 120 (P = 0.005). Control 66% had the highest rate of gas production, though not statistically different to EC 66% and 71% (P = 0.03). The objective of the third study was to evaluate digestibility, ruminal fermentation profiles, and feed intake behavior in steers fed high-forage diets containing individual components of SB. Twelve ruminally and duodenally fistulated Holstein steers (497 ± 19 kg) were assigned to one of four diets in a 4 x 4 Latin Square design. Diets included a control (CON; no SB components), solvent-extracted corn germ meal (Germ), corn bran (Bran), or corn steep liquor (Steep). Steers fed CON ate less than other treatments (P < 0.0001). Digestibility of protein of Steep diet was greater, for both ruminal and total tract digestion (P < 0.01). Additionally, Steep had higher total tract digestibility of starch (P = 0.03). Germ and Bran exhibited higher NDF digestibility than other treatments (P < 0.01), and CON had the lowest nutrients digestibility percentages. Diets with SB components decreased ruminal pH (P < 0.01) compared to CON. There were treatment differences (P < 0.01) in all feeding behavior variables. Steers on the Steep diet had the most frequent, shortest visits and the fastest intake rate, while CON steers had the fewest visits and slowest intake rate. Steers on Germ spent the longest total time eating. To conclude, type of grain fed in the backgrounding and finishing phases, but not silage, impacted overall system efficiency. In HMC, cultivar type showed minimal influence compared to DM content and storage length, yet the observed effect of EC on lactic acid concentration suggests potential for optimizing fermentation outcomes. Regarding SB, Steep contributed to greater digestibility percentages in our study, while Germ and Bran treatments were similar with respect to digestibility of most nutrients.Item Open Access Momma Pham’s Kitchen business plan(2025) Pham-Cook, LinaThis thesis presents a comprehensive phased operating and financial business plan for Momma Pham’s Kitchen, a Vietnamese restaurant concept, aiming to transition from a delivery-based business to a full-service brick-and-mortar establishment. The plan is structured around three growth phases: • Phase 1 - utilizing a commercial rent-out kitchen to offer delivery and catering services • Phase 2 - expanding into a food truck to build local visibility • Phase 3 - culminating in a fully operational brick-and-mortar restaurant. Several methods where used in this thesis that included local analysis of the restaurant industry, market assessment and analysis and viability of the restaurant concept as well as financial analysis that included net present value and a break even analysis. The thesis findings show that starting with a low-cost, flexible delivery service reduces risk and builds brand recognition, while the food truck offers a scalable, high-revenue business model in Phase 2. The final phase, the brick-and-mortar restaurant, introduces higher costs but enables long-term revenue generation and brand establishment in the community. This phased approach provides a financially viable roadmap for launching and scaling a new restaurant concept in a competitive food industry landscape. The research contributes to the understanding of how small-scale food businesses can strategically grow in stages, leveraging technology, customer engagement, and financial planning to maximize their chances of success.Item Open Access Understanding how a culture of wellness was established and is perceived at a large Texas public school district that has an award-winning employee wellness program(2025) Rodriguez-Sarabia, CordeliaThe COVID-19 global pandemic not only transformed but also reinvented the U.S. workforce, with many workers returning to the workplace demanding more work–life balance options for increased quality of life and health. As a result, many employers explored employee health promotion programs, also known as employee wellness programs (EWPs). Wellness programs in the academic setting, however, are typically designed and implemented for students, not faculty and staff. Historically corporations have been the leaders in instituting EWPs (Amaya et al., 2019). Wellness programming is consistent with the college mission, making it ideal to offer programs to their employees (Linnan et al., 2010). An obstacle for academic institutions, like colleges, is that they have unique challenges due to their large and diverse employee population, including maintenance staff, administrators, and faculty from different disciplines (Hill-Mey et al., 2015). In addition, few specific examples how to establish a successful EWP and a culture of wellness on community college campuses are available. In fact, the limited amount of community college EWPs that have received recognition for creating a culture of wellness was the reason for a change in the study site. The purpose of this study was to understand how a culture of wellness was established and perceived at the United Independent School District, a large Texas public school that has received recognition for their EWP from the American Heart Association for several years. Understanding key elements of their EWP can provide value to other academic institutions, like community colleges, that are trying to establish a culture of wellness at their campus and may contribute to policy or practice for such initiatives.
