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.

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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, Cordelia
The 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.
Open Access
Discovering the “why”: A qualitative study exploring alignment between an individual’s purpose in life and their work in academic advising
(2025) Thomas, Ashley
Finding and articulating purpose in life has been both an individual pursuit and a line of research for individuals and scholars for decades. Viktor Frankl (1959/2006) noted that purpose in life is profoundly human, individually unique, and exists in each person. In recent decades, the research on purpose in life has grown substantially and has revealed that individuals who have a clear sense of their purpose in life also exhibit a variety of positive life characteristics both personally and professionally. Scholars are beginning to explore the associations between purpose in life and various career groups such as priests, nurses, and social workers. However, at the time of this study, no research has been found around purpose in life as it relates to academic advisors in higher education. This narrative inquiry engaged the theoretical frameworks of Frankl (1959/2006) and Dewey (1938) to enhance understanding of the data. Qualitative analysis revealed that the exploration of life stories allowed primary-role academic advisors to connect with emotions which led to the ability to interrogate the individual meaning assigned to the experiences and, subsequently, a deeper understanding of themselves. Having an unbiased partner to help interrogate those life experiences was an important part of the process. Furthermore, having an awareness of their purpose led to a more intentional focus on the relational aspect of the advising relationship while enhancing individual feelings of resilience in their work. Finally, primary-role academic advisors acknowledged potential conflicts between their purpose and the goals of their institution. Participants identified resources that they felt would help to mitigate these challenges and shared that having an awareness of their purpose would help guide them in their professional goals and potential career moves. Following the presentation of the data, implications for advisors understanding the alignment between their purpose in life and their work are presented and limitations in the current study are discussed with suggestions for future research.
Open Access
Ranch sustainability strategies, Kansas Extension priorities and a web mapping tool for cow-calf wintering practice improvements
(2025) Boyer, Will
Sustainability of beef cattle production is a prominent issue of interest among scientists, consumers, retail corporations and producers. Stewardship practices of cow-calf producers are uniquely suited to provide critical ecosystem services (USRSB, 2019). Two Extension publications describing two general ranch sustainability strategies were drafted from two literature review subjects. One is community oriented, and the other is an ecologically oriented approach to supporting prairie rangeland stewardship. Two other, more specific, cow-calf ranch sustainability concerns were also reviewed: water quality associated with winter feeding practices, and eastern redcedar prairie forestation. Survey research on related Extension education needs was analyzed and used along with the literature reviews to guide the selection of one of the review subjects to become the selected concern to address with aid of a web mapping application. The web mapping tool facilitates decision making about winter feeding practices and their impact on water quality. Extension program prioritization survey analysis answered these survey research questions: 1) how do Kansas beef cattle owner respondents rank the importance of a) animal wellbeing, b) environmental policy, c) grassland, d) trees, e) water, f) invasive species, g) soil, and h) wildlife; and 2) how do these rankings differ from those of non-beef cattle owner respondents. Results suggest that grassland, water, soil, and animal wellbeing could be considered Extension education needs important to Kansas beef cattle owners and to other Kansas citizens based on nonparametric analysis and on the central tendency of the respondent answers reported as medians. These needs are, consequently, recognized as important ranch sustainability education topics for addressing the needs of rancher as well as expectations of others in Kansas. Cow-calf ranch management during the winter and spring months has considerable impact on these important topics, particularly the location and management of winter feeding sites. Feeding sites are traditionally located near streams for the availability of unfrozen water and wind protection. Riparian areas, rugged terrain and associated trees are commonly the source of protection important to animal wellbeing. Structural windbreaks and planted trees provide ranchers additional feeding site options with nearby wind protection. Meanwhile, tree planting and fire suppression are causing loss of prairie resources largely due to expansion of eastern redcedar across the prairie. Prairie forestation is rapidly degrading natural wildlife habitat and biodiversity. In addition to winter feeding site water quality, prairie forestations is clearly another major ranch sustainability concern in need of Extension education. However, the relative importance of trees, invasive species and wildlife seen in the survey results suggest that prairie forestation may be a less important issue than water quality associated with livestock feeding sites. The literature review also indicated that Great Plains Extension education on prairie forestation is well led by states adjacent to Kansas and say that detailed mapping is not particularly useful in rancher efforts to address prairie forestation. Literature review and Extension program prioritization survey analysis helped identify winter feeding site selection and management as the chosen subject for the instructional web mapping decision tool. The web mapping application provides necessary geographic information system (GIS) mapping data and video instruction for using a USDA NRCS feeding site assessment process, all within a single graphic user interface. The intended audiences are ranchers in Milford Lake watershed and their natural resource advisors. Advisors include local Extension Agents and watershed coordinators. It was hypothesized that female beef cattle owners consider animal wellbeing to be of higher importance than do male beef cattle owners. Survey research analysis suggested that was true, so women-in-agriculture workshops could be good venues for initial delivery of the web mapping application.
Open Access
Targeted whole genome sequencing protocols for African and classical swine fever viruses.
(2025) McDowell, Chester
The increasing availability and feasibility of sequencing has facilitated the advancement of infectious disease research including pathogen discovery, phylogenetic characterization, and viral evolution. Sequencing data combined with clinical disease, virulence, and viral dynamics data, can reveal a more complete understanding of viral evolution for the development of novel and effective control measures. Furthermore, experimental infection studies contribute to our understanding of clinical disease and viral dynamics when there is limited information such as with a novel pathogen or viral strain and provide critical reagents to evaluate the performance of available diagnostics and to develop new ones. African swine fever (ASF) an infectious viral disease caused by African swine fever virus (ASFV) that causes high mortality in domestic swine and wild boar (Sus scrofa). Since the outbreak in 2007 in the country of Georgia, ASFV has continues to spread and remains as a current global threat. In 2019, an African swine fever virus (ASFV) outbreak was reported in Mongolia; due to the limited information from field observations, we conducted an experimental infection of domestic pigs to further evaluate and characterize the progression of clinical disease, virulence, and pathology of an ASFV Mongolia/2019 field isolate (ASFV-MNG19). The study demonstrated that ASFV-MNG19 is a virulent genotype II ASFV strain that causes acute ASF in domestic swine. Controlled experimental studies like this one, are important to evaluate the genetics, virulence and clinical progression of emerging viruses and different variants/strains described in the field, and to aid in the development and validation of diagnostic tools used by regulatory agencies for the rapid detection and implementation of mitigation strategies. Targeted whole genome sequencing protocols are crucial for the rapid identification and complete genetic characterization of emerging and high consequence viral pathogens for outbreak investigations and understanding viral evolution for the development of novel and effective control measures. Such protocols are lacking for two high consequences viral pathogens affecting swine, ASFV and classical swine fever virus (CSFV). In order to fill this gap, we developed independent panels of primers spanning the genomes of ASFV and CSFV to generate approximately 10kB and 6kB amplicons, respectively, providing whole genome amplification. The targeted protocols for these viruses were tested using cell culture-derived viruses and clinical samples generated by our experimental infection studies in swine. These protocols resulted in an average coverage greater than 1000X for ASFV with 99% of the genome covered, and 10,000X-20,000X for CSFV with 97% to 99% of the genomes covered when sequenced on the Oxford Nanopore MinION platform. These protocols will be important tools to assist in early pathogen detection and genetic characterization of these high consequence swine viruses in outbreak and surveillance situations globally and within the United States, should an outbreak occur. Targeted whole genome sequencing protocols were also developed for the emerging zoonotic viral pathogen, SARS-CoV-2, to evaluate the viral competition between ancestral and novel variants in a susceptible host. We conducted a competition experiment whereby adult white-tailed deer (WTD) were co-infected with a lineage A and lineage B alpha variant SARS-CoV-2 isolates. The percent composition of lineage A and B viruses were evaluated using lineage A and B-specific RT-qPCR assays and targeted whole genome sequencing with a BLAST-based analysis. Using the developed protocols, we obtained that the SARS-CoV-2 lineage B alpha variant had improved fitness compared to the lineage A virus in adult WTD. This study demonstrates that sequencing data and bioinformatic pipelines can be used to evaluate strain composition in the presence of a co-infection. The targeted whole genome sequencing protocols developed here can be applied to investigate co-infection competition studies or to evaluate emerging viral variants through single nucleotide variant analysis, providing more information on the viral dynamics and evolution of these high consequence pathogens.
Open Access
Examining the lived cultural experiences of veterans at military friendly community colleges: A narrative inquiry
(2025) Miller, Matthew
Military veterans represent a unique community college demographic with a powerful cultural background that informs their approaches to learning, campus interactions, and challenge negotiation styles. Community colleges place a special emphasis on recognizing the cultural background of veterans and tailor support services and campus resources to embrace culturally specific inclusivity philosophies. These philosophies manifest as campus resource centers, targeted student support frameworks, and inclusive practices that recognize the important influence of culture on the military veteran student experience. The purpose of this qualitative narrative inquiry study was to explore the lived cultural experiences of veterans at a military friendly community college. This study was an exploration of a challenging student experience that is influenced heavily by powerful cultural background considerations and highlights the cultural implications associated with difficulties and successes. This study found that challenges with transition from military to community college student, interpersonal relationships, and campus acclimation have foundations in military culture. Successful use of skills gained from military culture was vital to veteran student success and influenced military student behaviors and attitudes positively. By identifying specific cultural experiences and their implication on the student experience, this study established direct evidence of a cultural confluence that complicates the military veteran community college journey.
Embargo
A diversified exploration of beef cattle genetics: miRNA and beef bull fertility in beef and dairy female populations
(2025) Shaffer, William
This dissertation represents a conglomeration of many different topics in the field of animal breeding. Topics explored include analysis of micro ribonucleic acid (miRNA) expression as it relates to quantitative traits, genetic analysis of sire conception rate (SCR) in dairy cow and beef heifer populations, and the genetic correlation between SCR in both populations. The objectives of the miRNA project were to elucidate differentially expressed (DE) miRNA resulting from changes in phenotypic expression of average daily gain (ADG), daily mean dry matter intake (dmDMI), and daily mean water intake (dmWI), validate these miRNA with DE in their predicted gene targets, and to gain insight on biological functions of predicted gene targets. We found that factorizing the three traits with k-means clustering or classifying observations greater or less than 1 standard deviation from the mean as high or low, respectively, yielded the most power to discover DE miRNA and mRNA. While multiple predicted gene targets were validated for several significantly DE miRNA, no gene ontology or gene pathways were significantly associated with the validated gene targets. Almost all gene targets were associated with lipid metabolism and lipid deposition in previous literature, which may be related to dmDMI and ADG. Exploration of biochemically connected traits to further improve power may be warranted. The objectives of the SCR project were to estimate the heritability of beef SCR in a dairy cow and beef heifer population as well as to estimate the genetic correlation between the two populations. The estimated heritability of SCR in the dairy cow and beef heifer population was exceedingly low at 1.74% (95% confidence interval 1.51% to 1.95%) and 2.10% (1.66% to 2.62%), respectively, but the 95% confidence intervals provided evidence for a weakly heritable component. The genetic correlation between SCR in the two populations was estimated at 0.02 (-0.13 to 0.19). This indicated that beef SCR records from dairy cows and beef heifers should not be utilized in the prediction of one another. Finally, exploration of other methods to improve male fertility may yield more genetic progress than selection on SCR given the low heritability and problems associated with data collection.
Embargo
Developing and validating a multi-dimensional scale for freshness perception of home air-care products
(2025) Yang, Gongshun
Freshness is a complex concept that encompasses both physiological and psychological dimensions. The goal of this dissertation is to develop and validate a standardized scale that measures consumer perceptions of freshness in home fragrances comprehensively, addressing a major gap in understanding freshness perception across different contexts and products. In the first phase, a qualitative approach was used to explore consumer terminology that contributes to freshness perception of home fragrances. Focus groups and E-commerce comment reviews helped identify key dimensions of freshness, including emotional and psychological factors, environmental elements, physical sensations, product context, and functional roles. These findings provide an understanding of how freshness is experienced by consumers, emphasizing aspects such as comfort, air quality, and lightness of scent. In the second phase, the scale was refined through a national survey. Factor analysis was used to ensure reliability and validity. Results confirmed four key dimensions of freshness perception such as environmental functionality, personal productivity, contextual associations, and emotional nostalgia. These dimensions had high internal consistency indicated by Cronbach’s alpha and highlight the importance of emotional, sensory, and environmental attributes in shaping consumers' understanding of freshness in home fragrances. In the third phase, the validated freshness scale was used in the context of product usage to determine its effectiveness in capturing consumer perceptions of home fragrances. The effectiveness of the freshness scale was further demonstrated. The findings showed that freshness involves more than just a pleasant fragrance; it also contributes to creating a cleaner, more comfortable environment. A Linen Clean scent, which enhances cleanliness and comfort perception, was rated as the most “fresh”. The results suggest that product development may focus on both sensory and environmental aspects to better meet consumer needs and expectations
Open Access
A case study of student perceptions of mental health services at three Maine community colleges
(2025) Stoldt, Tyler
The mental health needs of community college students have gained increasing attention, particularly in light of the exacerbating effects of the COVID-19 pandemic. While mental health services on college campuses have evolved, little research has explored how students perceive and engage with these resources within the unique environment of two-year institutions. The purpose of this qualitative case study was to develop an understanding of community college students’ perceptions of mental health services. The public information and the description provided by the counseling services administrator and program documents at three Maine community colleges were also collected to see if there was a relationship with the students’ perceptions. Data were collected through semi-structured interviews and documents and analyzed using Reflexive Thematic Analysis to identify shared patterns and themes. The theoretical framework for this study is Social Safety Theory, which emphasizes the importance of fostering inclusive and emotionally secure environments to mitigate social threats. Findings highlight the critical need for visible, accessible, and confidential mental health services, as well as the importance of addressing stress and isolation through proactive engagement. The study findings contribute to the understanding of mental health service delivery in community colleges and offer practical implications for enhancing student support systems in these institutions.
Open Access
Evaluation of bioprocessed soybean meal as a protein ingredient in extruded dog and cat diets
(2025) Chen, Youhan
The utilization of traditional soybean meal in pet food has been limited by its low methionine content and flatulence-causing oligosaccharides. Microbially enhanced soybean protein (MEP) and Aspergillus oryzae fermented soybean meal (F-SBM) are bioprocessed soybean meal products with improved nutritional value. The objectives of this thesis were to determine: 1) the optimal inclusion level of MEP for extruded pet food to enhance nutrient utilization and palatability, 2) the optimal A. oryzae fermentation process to improve soybean meal protein composition, and 3) the performance of F-SBM compared to traditional soybean protein products in extruded dog food. The effects of MEP and F-SBM on extrusion processing, kibble characteristics, palatability, nutrient digestibility, and stool quality were assessed in dogs and cats. The first experiment evaluated dog and cat diets with increasing levels of MEP (0, 5, 10, and 15% substitution for soybean meal). The second experiment optimized inoculation dosage and fermentation duration to enhance protein content in soybean meal and compared a diet with 30% F-SBM to diets with either 30% traditional soybean meal (SBM), 30% traditional soybean meal and 1% Amaferm (AMF), or 18% soybean protein isolate (SPI). Diets were fed to 12 dogs or 12 cats in a 4x4 replicated Latin square design, with a 9-day adaptation period followed by a 5-day total fecal collection. Data were analyzed using a generalized linear mixed model (GLIMMIX, SAS version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and animal and period as random effects. In the first study, the replacement of traditional soybean meal with MEP increased (P＜0.05) kibble expansion in both dog and cat foods. Fecal dry matter output decreased (P＜0.05) in a linear manner as MEP increased in dog diets. Fecal quality in cats were not affected by MEP inclusion. Overall, nutrient digestibility was maintained with increased levels of MEP. Fecal ammonia showed a linear increase (P＜0.05) as MEP increased in cat diets. For palatability, dogs preferred (P < 0.05) diet with 15% soybean meal to diets with 5 or 10% MEP, while cats preferred (P < 0.05) diet with 10% MEP to a diet with 15% soybean meal. For the second experiment, an Aspergillus oryzae spore inoculation dosage of 1×104 spores/g and fermentation duration of 36 hours were found to be optimal for increasing protein content and avoiding increasing soluble dietary fiber in the soybean meal. The F-SBM had improved (P < 0.05) nutrient profile and increased (P < 0.05) specific mechanical energy and kibble expansion compared to traditional soybean meal during extrusion. Fermentation also decreased (P < 0.05) content of sucrose and oligosaccharides in soybean meal. Fecal quality and nutrient digestibility were similar among dogs fed on the SBM, the FSBM and the AMF, while those of dogs on SPI had less (P < 0.05) fecal output and greater (P < 0.05) nutrient digestibility. Colonic fermentation was the greatest (P < 0.05) in dogs on the AMF and the least (P < 0.05) in dogs on SPI, with dogs on SBM and FSBM intermediate. Dogs preferred SBM to FSBM but did not show preference between SBM and SPI. Overall, the bioprocessed soybean meals did not affect fecal quality, general nutrient digestibility when fed to cats and dogs compared to diets with traditional soybean meal. To maintain palatability, the inclusion level should not exceed 15% of the diet. Further research is needed to explore health benefits and more processing characteristics of bioprocessed soybean meal as a protein source in pet foods.
Embargo
Post-translational regulation and gene repression mechanisms of Arabidopsis HD-Zip IV transcription factors
(2025) Ahmad, Bilal
Class IV homeodomain leucine-zipper (HD-Zip IV) transcription factors (TFs) drive epidermal differentiation and cell fate determination in plants. These proteins contain a conserved domain architecture comprising a DNA-binding (DB) homeodomain (HD), zipper loop zipper (ZLZ) dimerization domain, steroidogenic acute regulatory (StAR) protein-related lipid transfer (START) domain, and START-adjacent domain (STAD). Despite decades of research, their post-translational regulatory mechanisms remain unexplored. The studies herein focused on the nuclear import and transcriptional repression mechanisms of HD-Zip IV proteins. Arabidopsis thaliana members GLABRA2 (GL2) and PROTODERMAL FACTOR2 (PDF2) served as models to elucidate the nuclear localization mechanisms of HD-Zip IV TFs. GL2 contains a monopartite nuclear localization sequence (NLS) overlaps with HD. Mutational analyses showed that the NLS is essential for PDF2 and GL2 nuclear localization, while EYFP-NLS live imaging confirmed its sufficiency. Genetic dissection provided evidence that DNA binding and nuclear localization are separable functions despite the partial overlap between the NLS and HD. Protein-protein interaction (PPI) analyses confirmed NLS-dependent interactions between GL2 and importin alpha (IMPa) isoforms. In accordance with this, IMPa triple mutants (impa-1,2,3) exhibited defects in EYFP:GL2 nuclear localization and trichome development. The gene repression mechanisms of HD-Zip IV TFs were dissected by studying GL2 and two other HD-Zip IV members, Arabidopsis thaliana MERISTEM L1 LAYER (ATML1) and HOMEODOMAIN GLABROUS11 (HDG11). GL2 possesses two ethylene-responsive element-binding factor-associated amphiphilic repression (EAR) motifs, comprising an LxLxL pattern on the amino (N)- and carboxy (C)-termini. Mutations in the N-terminal EAR motif (gl2[superscript EARN]) resulted in partial functional defects. In contrast, C-terminal mutations led to complete loss-of-function, likely due to protein misfolding. A modified EAR motif, SUPERMAN REPRESSIVE DOMAIN X (SRDX) fusion to gl2[superscript EARN], rescued epidermal defects. PPI analysis using yeast two-hybrid (Y2H) and co-immunoprecipitation (Co-IP) revealed EAR-motif-dependent interactions between GL2 and the TOPLESS (TPL) and TPL-RELATED corepressor proteins. Future experiments, such as RNA sequencing and TPL/TPR mutant analyses, will further elucidate GL2 transcriptional targets and repression mechanisms. Unlike GL2, ATML1 and HDG11 lack an identifiable repressive domain and interact with a small EAR-motif-containing adaptor protein, GL2 INTERACTING REPRESSOR 1 (GIR1), to orchestrate their transcriptional target expression and cell fate determination. A gir1 T-DNA insertion mutant displayed giant cell overproduction in the sepals, similar to ATML1 overexpression. PPI via Y2H and Co-IP revealed that the GIR1 C-terminal cysteine residues are required for the interaction with ATML1 and HDG11 STAD, whereas the N-terminal EAR motif is critical for the interaction with TPL and TPR. Co-IP experiments also showed that GIR1 acts as an adapter to link ATML1 with TPL/TPR corepressors. Genetic complementation experiments demonstrated that wild-type GIR1, but not EAR or cysteine mutants, can rescue the gir1 mutant phenotype, highlighting the importance of EAR and cysteine motifs for GIR1 function in planta. Collectively, these findings suggest a model in which GIR1 recruits TPL/TPR to ATML1 and HDG11 target loci for balanced regulation of gene expression to orchestrate epidermal cell fate. Overall, these studies have mechanistically uncovered the nuclear localization and gene regulatory mechanisms of Arabidopsis HD-Zip IV TFs in fine-tuning transcriptional target expression for proper epidermal development. Given that the epidermis is the first line of defense and HD-Zip IV orthologs are present in major agronomical crops, these findings can be broadly applied to guide molecular toolkits to improve yield and resilience to environmental stresses.
Open Access
Examining the frustration construct: systematic comparison to stress and framework application
(2025) Sargent, Moana
The current study aimed to polish the frustration construct through comprehensive literature review and comparison to stress. This was achieved through semantic analysis of stress and frustration and comparison of these semantic differences to actual conceptualizations of the two constructs as well as their associated situations. Based on Affective Events Theory (Weiss & Copranzano, 1996), the current study also aimed to clarify the affective experiences associated with frustration to better understand how related behaviors and attitudes manifest. Lastly, it tested a model of frustration based in a frustration framework (González-Gómez & Hudson, 2023) and conceptualized it within Effort Reward Imbalance (Siegrist, 1996). Key findings were that frustration and stress were indeed semantically similar and some small nuances in frustration experiences identified; some established frustraters were contributed more to stress. Frustration was best represented by a simplified model, including cognitive antecedents of goal blockage and effort and outcomes of guilt and hostility, and the relationship between cognitive antecedents and frustration was consistently moderated by individual differences.
Open Access
Photoelectron – residual-ion entanglement in streaked shakeup ionization of helium
(2024) Shi, Hongyu
Streaked photoelectron emission spectra access the correlated dynamics of photoelectrons and residual target electrons with attosecond temporal resolution. We calculated ab initio single-ionization spectra for photoemission from helium atoms by co-linearly polarized ultrashort XUV and assisting few-femtosecond IR pulses. Distinguishing direct and shake-up ionization resulting in ground-state and excited (n=2,3) He⁺ residual ions, respectively, we examined the effects of the correlated photoemission dynamics on the photoelectron phase-accumulation as a function of the observable photoelectron detection direction and kinetic energy, and XUV -- IR pulse delay. We tracked the dynamical evolution of the residual ion in relative streaked photoemission delays and found dominant contributions for shake-up emission from the residual ion -- photoelectron interaction. These are in very good and fair agreement, respectively, for n=2 and n=3 shake-up photoemission along the pulse-polarization directions, with previous experimental and theoretical investigations [M. Ossiander et al., Nature Phys 13, 280–285 (2017)] and reveal a strong photoemission-direction dependence for shake-up ionization due to the coupling between the photoelectron and evolving residual-ion charge distribution in the IR-laser field.
Open Access
Effect of rum amount and functional ingredients on physical properties and microwaveable reheatability of rum cake
(2024) Phalen, Kyle Andrew
Rum cake remains a popular consumer good in the United States and Caribbean islands. A single-serving, frozen rum cake that is ready-to-eat after 1 min of microwaving was developed, however microwaving of cereal-based goods often leads to textural problems. To minimize textural defects (tough, rubbery, and gummy) caused during microwaving, functional ingredients such as modified starches, emulsifiers, and hydrocolloids are commonly added to cakes. The two main objectives were: 1) to determine how rum amount affects texture and structure of fresh rum cake, and 2) to analyze two functional ingredients (modified starch and glycerol monostearate (GMS)) on final quality of fresh rum cake and frozen then microwave reheated rum cake. To determine the effect of rum, four rum cake formulations were analyzed (0% (control), 7.6%, 10.1%, 12.6% rum w/w, true %). Water was added as needed to formulations to obtain the same moisture level and all other ingredients and processes were held constant. For the functional ingredients experiment, three levels of modified starch (0.21%, 0.42%, 0.63% w/w, true %) and two levels of GMS (0.11% and 0.17% w/w, true %) were analyzed using a 2x3 factorial design. Control samples contained no modified starch or GMS. Specific gravity, consistency, and final temperature of the batters were measured along with final cake height to determine final cake volume. Physical properties of cakes were also analyzed through texture analysis (cake firmness and elasticity) using a TA-XT Plus Texture Analyzer. For the alcohol study, rum presence showed an increase in elasticity and cake height (p<0.05). The actual amount of rum (7.6, 10.1%, and 12.6%) was not significant, but each treatment that contained rum was significantly different from the control (0% rum). Rum presence of significantly reduced moisture loss of cakes (p<0.05), which could be a contributing factor to the increased elasticity and height of rum-containing formulas. The increase in elasticity and height are both seen as positive attributes from a consumer acceptance standpoint, as consumers are looking for high volume cakes that will not crumble under stress. These results suggest that the presence of rum in a cake creates a more elastic cake with greater volume and height, indicating a physiochemical effect of rum in the batter or through the prevention of moisture loss. In the functional ingredient experiment, the addition of a pregelatinized waxy maize starch increased the batter consistency (p<0.05). In fresh cakes, the addition of starch and GMS at low levels resulted in decreased firmness. All three starch levels and both GMS levels tested significantly increased cake elasticity when compared to the control. For both firmness and elasticity, the presence of the ingredient was more impactful than percent added. Decreased firmness and increased elasticity are both seen as positive textural attributes by consumers. In frozen and then microwave reheated cakes, no significant differences were observed in peak firmness or height. Elasticity significantly decreased (p<0.05) when comparing control versus high starch cakes and control versus low GMS cakes. These results indicate that the modified starch and GMS used in this experiment did not have the expected positive impact on physical properties of frozen, microwave reheated rum cakes. Procedural changes to the length of frozen storage or reheating method may provide some additional learnings on the freeze-thaw effectiveness of these ingredients. Overall, the addition of rum to a cake batter creates an airier, more elastic cake, although the level of rum was insignificant. The addition of functional ingredients such as modified starch and GMS had a positive impact on physical properties of fresh cakes in the form of decreased firmness and increased elasticity, but this same impact was not observed in cakes that had been frozen and then microwave reheated.
Open Access
Intermediate wheatgrass (Thinopyrum intermedium) and grain sorghum as novel, sustainable ingredients in extruded precooked pasta and expanded snacks – Life cycle assessment, physicochemical properties and product quality
(2025) Rivera, Julia
This thesis explores the potential of Intermediate Wheatgrass (IWG) and sorghum as sustainable alternatives to conventional grains in the production of extruded precooked pasta and expanded snacks, while evaluating their environmental impacts through a life cycle assessment (LCA). IWG, with its deep root system, enhances soil health and carbon sequestration, addressing challenges like soil erosion and high water usage. Sorghum offers sustainability benefits in water-scarce regions, with comparable or improved product performance. Six pasta formulations incorporating wheat, IWG, and sorghum were assessed for functionality and cooking performance. Pasta made solely from wheat exhibited the highest cooking loss at 5.6%, while IWG pasta had 3.9%, and sorghum pasta achieved the lowest cooking loss at 1.9%. RVA analysis revealed wheat’s higher peak viscosity (1064 cP) compared to sorghum (979 cP) and IWG (443 cP), suggesting differences in starch binding and degradation that influenced cooking outcomes. The study also examined the properties of IWG and sorghum in expanded snack production. IWG snacks exhibited the highest density at 0.28 g/cm³ compared to corn (0.12 g/cm³) and sorghum (0.14 g/cm³), indicating potential differences in textural outcomes. Expansion ratios revealed that sorghum achieved 10.22, significantly higher than IWG's 5.80, while corn reached 10.58. In terms of hardness, IWG snacks measured 22.95 kg, notably harder than corn (15.54 kg) and sorghum (12.96 kg). These findings highlight opportunities to balance texture and sustainability in snack formulations. LCA results showed sorghum with the lowest Global Warming Potential (GWP) at 0.09 kg CO2 eq/kg for snacks and 0.11 kg CO2 eq/kg for pasta. IWG exhibited higher direct GWP (0.31 kg CO2 eq/kg for pasta) but transformed into a carbon sink when considering carbon sequestration and straw allocation, reducing net GWP to -0.7 kg CO2 eq/kg. These findings underscore IWG’s potential to offset emissions through soil organic carbon sequestration (42 tons C/hectare), while sorghum offers low emissions with favorable product properties. This research highlights the environmental and functional advantages of integrating IWG and sorghum into food systems, contributing to more sustainable agricultural practices and product development.
Open Access
Dimuon production in the MicroBooNE detector
(2025) Martinez Figueroa, Norman Amilkar
This analysis studies the production of the rare signal with two muons (dimuon) in the final state at µB using the Booster Neutrino Beam (BNB) as source of neutrino interactions. The main background source for the dimuon signal are pions. Differentiating muons and pions has been challenging at µB because the tracks left by these particles are almost identical. This analysis faces this problem using a supervised classifier algorithm called boosted decision tree (BDT). A Monte Carlo simulation (MC) enhanced dimuon signal sample was produced to train a BDT capable of recognizing this signal. A set of variables that show some discrimination characteristics was used to perform the training. A MC neutrino interaction simulation sample was used to estimate the background. Estimations of dimuon production in real data samples were made for different cases. Additionally, an analysis of the systematic uncertainties, fake data studies, and BDT performance checks were obtained.
Open Access
Interactions of antioxidants and phenoloxidase reactions in Manduca sexta hemolymph
(2025) Morabito, Sequoyah
Melanization is an important component of the insect innate immune response. Melanization occurs when an insect is exposed to pathogens such as bacteria or fungi. Phenoloxidase (PO) is a key enzyme in the synthesis of melanin. Recognition of bacterial peptidoglycan initiates a cascade of serine proteases, which activates PO. PO then hydroxylates tyrosine and oxidizes DOPA and dopamine, derived from tyrosine, to ortho-quinones. These participate in redox reactions that finally result in synthesizing melanin. Ortho-quinone formation and the redox reactions produce reactive oxygen species (ROS), which may help in eliminating pathogens but may also be harmful to the host insect. Insects may regulate oxidative damage to themselves. In this study, PO in hemolymph was activated similarly when plasma was exposed to either Lys type or DAP type bacterial peptidoglycans. However, lower amounts of Lys type peptidoglycans were able to stimulate PO more when compared to DAP type peptidoglycans. Colorimetric measurements revealed that M. sexta plasma contains a high concentration of ascorbate that significantly decreases when plasma PO is stimulated with peptidoglycan. Unexpectedly, PO activation also resulted in an increase in the total antioxidant capacity in plasma, which may be caused by the increased concentrations of DOPA produced during the melanization response, since DOPA can act as a reducing agent. Mass spectrometry, performed on M. sexta whole hemolymph and plasma, was used to reproducibly determine concentrations of total thiols, total reduced thiols, reduced glutathione, oxidized glutathione, cysteine, cystine, and glutathione-ss-cysteine, revealing that antioxidants are predominantly located in plasma and not hemocytes. Mass spectrometry was used to determine changes in concentrations of the following antioxidants and metabolites in plasma after stimulation of PO activation with peptidoglycan: total reduced thiols, total oxidized thiols, percent oxidized thiols, total glutathione, total cysteine, total homocysteine, total cysteine-glutathione, free glutathione, oxidized glutathione (GSSG), free cysteine, cystine, glutathione-ss-cysteine, ascorbate, dehydroascorbate, tyrosine, DOPA, dopamine, and tyrosine glucoside. Stimulated plasma had a significant decrease in concentrations of glutathione, cysteine, ascorbate, and tyrosine. Concentrations of DOPA significantly increased in stimulated plasma samples while the concentration of dopamine did not change, demonstrating the hydroxylation of tyrosine and suggesting that DOPA is the predominant diphenol used during melanization. These results show that the redox environment in M. sexta plasma is highly reducing and suggests that shifts in redox potentials and regulation of the redox environment may not only regulate PO activity but may also prevent oxidative damage to the host.
Embargo
Development of processing technologies for gluten-free and plant-based food applications
(2025) Pulivarthi, Manoj Kumar
The increasing demand for gluten-free and plant-based products has driven the need for high-quality alternative ingredients that offer both functionality and sustainability. Sorghum and pulses like yellow peas and red lentils are promising sources, requiring advanced processing techniques to optimize their use in diverse food applications. This thesis investigates milling and protein fractionation processes to enhance the functionality and application potential of sorghum- and pulse-based flours and protein fractions. A detailed review of current research on dry fractionation for producing functional, protein-rich ingredients highlights its sustainable and eco-friendly advantages as an alternative to intensive wet fractionation. In Chapter 3, a roller milling technique combined with ultrasound tempering (UST) was developed to produce high-quality white and sumac sorghum flours for gluten-free applications. UST significantly impacted milling yield, particle size, starch damage, and ash content. Notably, the milling yield of white sorghum increased from 73.3% (control) to 76.6–78.2% with treatment durations. A 1-minute UST enabled efficient bran separation, lowering ash content to 0.87% in white sorghum and 0.69% in red-tannin sorghum, compared to 1.05% and 1.4% in controls. This optimized milling approach proved suitable for both sorghum varieties, enhancing flour quality regardless of physical property differences. Chapter 4 examined the rheological properties and baking performance of UST-treated white and sumac sorghum flours. Mixolab and rapid visco analyzer (RVA) results demonstrated enhanced starch gelatinization and retrogradation, particularly in sumac sorghum. UST improved bread quality by reducing hardness and enhancing crumb structure, with the most notable improvements in sumac sorghum. While cookie quality was unaffected by UST time, both sorghum flours showed good cookie baking performance. In Chapter 5, roller milling settings were optimized to produce dehulled yellow pea and red lentil flours of various particle sizes (small, medium, and large) with minimal nutritional differences. The geometric mean diameters for red lentil flours were 56.05 μm (small), 67.01 μm (medium), and 97.17 μm (large), while yellow pea flours ranged from 41.38 μm to 98.31 μm. Starch damage increased with smaller particle sizes due to intensified milling, impacting flowability and suggesting roller milling as an effective technique for producing flours with varied functional applications. The final study compared dry and wet fractionation methods for producing protein-rich red lentil fractions. Air classification, a dry fractionation method, achieved up to 60.53% protein content with a recovery of 19.52%. Optimal protein purity and yield (57.84% protein at 6,000 rpm with 29.96% recovery) were achieved with a 22 μm cut point. Wet fractionation produced protein isolates with up to 89.23% protein content, while the mild-alkaline red lentil concentrate reached 64.24%. Functional testing showed the wet-extracted isolate excelled in emulsifying capacity (EC), water absorption (WAC), and oil absorption (OAC), while dry-fractionated proteins offered enhanced foaming, solubility, and gelling properties, preserving native functionality. These findings provide sustainable solutions for gluten-free baking and plant protein enrichment, supporting the development of high-quality, nutritionally enriched food ingredients to meet growing consumer and industry demands.
Open Access
Probiotics in feedlot cattle: implications for reducing liver abscess pathogens
(2025) Moe, Maggie Catherine Taylor
Liver abscesses are a significant health and economic issue in feedlot cattle, predominantly caused by Fusobacterium necrophorum, Trueperella pyogenes, and Salmonella enterica. These abscesses commonly result from ruminal acidosis or rumenitis associated with high-grain diets. While liver abscesses have traditionally been controlled with in-feed antimicrobials like tylosin and chlortetracycline, increasing concern over antimicrobial resistance drives the need for alternative therapies. This study aimed to investigate the potential of lactic acid bacteria (LAB) isolated from liver-abscess-free cattle as natural inhibitors of liver abscess-causing pathogens. Between 2 beef processing plants, ruminal content samples from 56 cattle were collected originating from 28 feedlots. From the samples collected, 560 LAB isolates were obtained, and broth cultures were separated into two cell-free aliquots: one with neutralized pH and the other remaining unaltered. Isolates were then screened for antimicrobial activity against the target liver abscess pathogens using agar-well diffusion assays. Results indicated that non-pH-adjusted LAB supernatants exhibited zones of inhibition for all three pathogens, with F. necrophorum showing the greatest inhibition and highest isolate sensitivity. However, pH-adjusted LAB supernatants displayed no antimicrobial activity, suggesting pH plays a significant role in the inhibitory effects observed. In total, 14 LAB isolates exhibited broad-spectrum inhibition across all pathogens, although repeated trials showed variability between experiments, highlighting the potential influence of LAB supernatant composition and culture conditions. Our findings suggest that ruminal LAB may exhibit innate antimicrobial effects against liver abscess pathogens, with Lactobacillus species showing potential for use in probiotics products for cattle on high-grain diets. Further research is needed to characterize these LAB isolates, assess their consistency and efficacy, and determine suitability as direct-fed microbial species for livestock production. This study highlights the potential of probiotics as viable substitutes to traditional antimicrobials for managing liver abscesses in feedlot cattle.
Embargo
Study of the PD-1 expression in lung carcinoma cells and T lymphoblasts by Euglena gracilis water extract
(2025) DeVader, Sarah
Lung cancer is the leading cause of cancer related deaths in the United States. Natural products are a diverse source of anticancer compounds. Euglena gracilis (E. gracilis) is a unicellular freshwater green alga rich in nutrients that is used as a dietary supplement. It has been studied for its many properties, including anti-inflammatory, antiviral, and antitumoral. We have been investigating the preventative effects of E. gracilis against lung cancer development. Our previous studies demonstrate water extract from E. gracilis (EWE) possesses anti-cancer activity against lung carcinomas and stimulates T-cell cytotoxicity against lung cancer cells. However, it is unknown how EWE directly attenuates the growth of lung carcinoma cells and directly stimulates T cells, and what component(s) within EWE are responsible for these biological effects. In the current study, we investigated the relationship between EWE and the mRNA expression of PD-1 in lung carcinoma cells and T cells. Orally administered EWE in an orthotopic lung cancer syngeneic mouse model was revealed to increase the expression of PD-1 and PD-L1 in tumor-bearing mouse lungs, which was correlated with a decrease in tumor weights in the mice. In vitro, EWE was found to increase the mRNA expression of PD-1 and PD-L1 in both murine Lewis lung carcinoma (LLC) cells and murine splenocytes, and EWE also increased the mRNA expression of PD-1 and granzyme B in human Jurkat T lymphoblasts. Using the EWE-induced stimulation of these proteins as assay tools, the bioactive compound in EWE was purified by FPLC with a size exclusion column. Three specific fractions were found to increase the mRNA expression of PD-1 and PD-L1 in LLC cells and the mRNA expression of PD-1 and granzyme B in Jurkat cells. The FPLC fraction which showed highest bioactivity was further fractionated by C18 reverse phase HPLC. The resulting HPLC fraction that increased the expression of PD-1 in LLC cells was subjected to the structural analysis by liquid chromatography mass spectroscopy and nuclear magnetic resonance, which is currently underway. These results suggest that there is a relationship between the EWE-induced attenuation of lung tumor growth and the EWE-induced increased PD-1 expression, and that EWE treatment may enhance its therapeutic efficacy by stimulating antitumor immunity in lung cancer. The PD-1 stimulator present in EWE was preserved throughout fractionation with FPLC and HPLC in tandem, and, once identified, could provide clear insights into the mechanisms by which EWE achieves these biological effects.
Open Access
Field-scale quantification of methane and nitrous oxide agricultural emissions using micrometeorological approaches
(2025) Weerasekara, Chinthaka
Methane (CH₄) and nitrous oxide (N₂O) emissions from agricultural systems are significant contributors to global greenhouse gas (GHG) emissions, and accurate quantification of these emissions is essential for improving GHG inventories and evaluating mitigation strategies. This research employs the eddy covariance (EC) technique, artificial neural networks (ANN), and footprint analysis to address key challenges, such as spatial variability, data gaps, and footprint limitations, in measuring GHG emissions in dynamic agricultural environments. The objectives of this study were to: 1) assess the performance of the EC technique for measuring N₂O and CH₄ fluxes in agricultural systems; 2) develop ANN models to fill gaps in N₂O flux data; and 3) evaluate CH₄ emission rates from grazing systems using EC and footprint models. The first study focused on N₂O emissions measured using the EC technique in two contrasting agricultural environments: a cattle feedlot and a winter wheat field. In the cattle feedlot, average N₂O fluxes were low (0.0062 μ mol m⁻² s⁻¹) during winter, with emission spikes that were not consistently linked to precipitation or temperature changes due to frozen soil conditions. In contrast, the winter wheat field exhibited higher variability, with emission rates peaking at 0.03 μ mol m⁻² s⁻¹ during warm, moist periods following nitrogen fertilization and rainfall. Footprint analysis in the cattle feedlot revealed that up to 70% of the measured flux contributions came from outside the feedlot boundary, driven by manure runoff and off-site sources. In the winter wheat field, N₂O fluxes were more evenly distributed within the footprint and closely associated with fertilizer applications and subsequent precipitation events. These findings demonstrate the necessity of continuous high-frequency measurements to capture the full temporal and spatial variability of N₂O fluxes in agricultural systems. The second study applied artificial neural networks (ANN) to fill data gaps in N₂O flux measurements at winter wheat fields. Data gaps, caused by equipment malfunctions, low-turbulence conditions, and extreme weather events, can significantly affect the accuracy of long-term flux data. The ANN models were trained using environmental variables, such as soil moisture, temperature, and wind speed, and demonstrated strong performance, achieving a coefficient of determination (R² > 0.85) between predicted and observed fluxes. At the winter wheat field, the ANN model successfully reconstructed missing flux data due to cold weather and sensor failures and filled gaps during elevated N₂O emissions following fertilization. These results highlight the importance of using advanced gap-filling techniques, such as ANN, to maintain the integrity of long-term GHG datasets, particularly in complex agricultural systems. The third study focused on quantifying CH₄ emissions from grazing systems using the eddy covariance (EC) technique in combination with flux scaling based on footprint analysis. Controlled CH₄ release experiments were conducted to simulate emissions from a small herd of cattle, allowing for the assessment of the EC system's accuracy in estimating CH₄ fluxes. The results revealed that CH₄ fluxes were consistently underestimated, with the calculated emission rates clustering around 30% of the actual release rate. This underestimation was linked to the footprint model’s difficulty in fully capturing contributions from the source area, especially at lower fetch percentages. Increasing the fetch to 90% improved source coverage but introduced instability and errors. These findings emphasize the need for more accurate footprint models to account for varying wind conditions and terrain complexities in grazing environments. The integration of these studies underscores the importance of continuous high-frequency measurements in capturing the variability of N₂O and CH₄ emissions in agricultural systems. Due to uncontrollable factors such as equipment failures and adverse weather conditions, data gaps are inevitable, making gap-filling techniques like ANN crucial for ensuring data continuity. Footprint analysis further improves the accuracy of emission estimates by addressing spatial variability in emission sources, particularly in grazing systems. This research advances the understanding of GHG emissions from livestock and crop production systems, contributing to more accurate emission inventories and the development of effective mitigation strategies in agriculture.

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