Theses and Dissertations at Montana State University (MSU)
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Item Using dietary dynamics to assess the efficacy of biocontrol and to predict the effects of warming water temperatures on salmonids(Montana State University - Bozeman, College of Letters & Science, 2024) Furey, Kaitlyn Marie; Chairperson, Graduate Committee: Christopher S. Guy; This is a manuscript style paper that includes co-authored chapters.Salmonids are coldwater fishes with substantial ecological and economic importance, particularly in the northern Rocky Mountains in Montana, USA, where fisheries are valued over US$750M annually. Georgetown Lake (Montana, USA) is renowned for its salmonid fishery. Although many anglers target kokanee (Oncorhynchus nerka) in Georgetown Lake, the body length of kokanee has typically been considered unsatisfactory. To reduce the density of kokanee and increase the average size, Montana Fish, Wildlife & Parks (MFWP) began stocking piscivorous Gerrard strain of rainbow trout (Oncorhynchus mykiss; hereafter Gerrard) in 2015 to consume kokanee. To assess the efficacy of biocontrol through the introduction of a piscivore to improve the size structure of kokanee, I used diet composition to determine the amount of predation on kokanee and to understand the feeding ecology of all potential predators. There was extremely low prevalence of piscivory and no evidence of Gerrards consuming kokanee. Gerrards exhibited a generalist feeding strategy and there was dietary and niche overlap and no difference in trophic position among Gerrards and trout. These findings highlight the unpredictability of predator-prey dynamics and the importance of evaluating management interventions, such as biocontrols. Additionally, this popular fishery could be in jeopardy because air temperatures in the region have warmed at twice the global average, leading to warmer water temperatures that could affect the thermal suitability for salmonids. Increased water temperatures can have sub-lethal effects, influencing growth, metabolism, and feeding rates of fish. Bioenergetics models were used to simulate the effects of warming water temperature on food consumption and growth for rainbow trout and kokanee within Georgetown Lake. My findings indicate that kokanee are more sensitive to warming than rainbow trout. While both species experience growth challenges as water temperatures exceed their optimal ranges, kokanee are particularly vulnerable, requiring higher food consumption to meet basic metabolic needs under elevated water temperatures. Thus, kokanee are likely to experience greater declines in growth compared to rainbow trout. Climate change will pose challenges for freshwater fisheries management, thus understanding how projected warming water temperatures may affect popular recreational fisheries can provide managers with information to establish reasonable expectations for fish growth.Item Estimating tool wear using multi-sensor data fusion and machine learning techniques(Montana State University - Bozeman, College of Engineering, 2024) Jones, Tanner Owen; Chairperson, Graduate Committee: Yang CaoModern manufacturing industries are being transformed by the integration of sensor technology, data science, and machine learning, leading to smarter, more efficient operations. Advancements in equipment health monitoring are crucial for improving productivity, extending equipment lifespan, and ensuring consistent product quality. In computer numerical control (CNC) machining, worn tools contribute to increased forces and vibrations, negatively impacting both machine performance and part quality. Traditional tool condition monitoring methods, which rely on manual offline inspections, result in machine downtime and decreased productivity. Modern tool condition monitoring methods involve monitoring tools based on single-sensor analysis. While a single sensor can detect tool wear within a machine, it fails to capture the full range of system behavior, potentially overlooking critical anomalies indictive of tool wear. To address these challenges, automated monitoring systems utilizing multisensory data and machine learning techniques have been developed, enabling real-time monitoring and prediction of tool wear. This research introduces a novel three-level data fusion framework for predicting tool flank wear in CNC machining. Force, vibration, and sound data was collected using various sensors during a CNC milling operation. The raw sensor data was processed and transformed into distinct statistical features to train machine learning models. A stacking ensemble method combining a random forest, artificial neural network, and extreme gradient boosting algorithm was employed to enhance predictive accuracy, achieving an R 2 value of 0.982, and root mean squared error of 37.146 micrometers. The proposed three-level fusion framework proved to be highly effective in predicting tool flank wear and shows great potential for monitoring the health of engineering equipment across a variety of industries.Item Restoration and pollinator conservation: strategies for controlling invasive annual grasses on degraded tribal grasslands(Montana State University - Bozeman, College of Agriculture, 2024) McRyhew, Ian Issaia; Chairperson, Graduate Committee: Jane M. MangoldInvasive annual grasses (IAG) threaten Intermountain foothill grasslands in northwestern Montana, and these grasslands are integral to the cultural and ecological well-being of the Selis, Ksanka, and Ql'ispe Tribes. This project aimed to increase native vegetation cover and test the tolerance of native grasses and forbs to herbicides commonly used to control IAG. Three components were evaluated: a field study at two sites on Tribal grasslands, a greenhouse study of species tolerance, and a baseline bee survey at the two field sites. In the field study, six herbicides and nine species were tested, with herbicide treatments applied fall 2021 through summer 2022, depending on label recommended timings, and seeding occurring spring 2021. Canopy cover of all species was measured in 2022 and 2023. Rimsulfuron, sulfosulfuron, and indaziflam effectively reduced IAG (up to 96% control), while propoxycarbazone, imazapic, and glyphosate were less effective. Drill seeding largely failed. Geranium maculatum, Cleomella serrulata, and Gaillardia aristata were present in low numbers in 2022 but absent in 2023. The greenhouse study evaluated tolerance of 12 plant species to four herbicides, focusing on seedling emergence, biomass, and injury symptoms. Herbicides reduced emergence and reduced biomass for the majority of species compared to the non-sprayed check. All forbs showed high injury ranks except Lupinus argenteus, which ranked moderate across treatments. All grasses had high injury ranks across herbicides except Thinopyrum intermedium, which had the least injury of all species under sulfosulfuron. Although T. intermedium and G. aristata showed some emergence in indaziflam-treated soil, indaziflam prevented the emergence of all other species. A baseline bee survey conducted over three summer months in 2023 at the two field sites identified 42 bee species from 14 genera and five families. Species richness analysis predicted 48 species at one site and 74 species at the other site, indicating a relatively even distribution of species. To effectively manage IAG, rimsulfuron, sulfosulfuron, and indaziflam can be prioritized, but should be integrated with planting of specific native species to improve establishment and minimize non-target impacts. Restoration efforts should incorporate pollinator-friendly species and engage stakeholders to align management with cultural and ecological goals.Item Influence of cottonseed oil on fat oxidation in steady state exercise(Montana State University - Bozeman, College of Education, Health & Human Development, 2024) Kropatsch, Katy Rose; Chairperson, Graduate Committee: Mary P. Miles; This is a manuscript style paper that includes co-authored chapters.Impaired fat oxidation is a common issue in individuals with chronic disease such as obesity and cardiovascular disease. Nutrition interventions aimed at increasing fat oxidation capacity could potentially have clinical relevance in delaying the progression and/or preventing chronic disease. Dihydrosterculic acid (DHSA), a bioactive component in cottonseed oil (CSO), has previously been seen to increase fat oxidation in mice. However, it is unknown the effect of CSO on fat oxidation in humans. The purpose was to determine the impact of a diet rich in either cottonseed oil (CSO) or olive oil (OO), consumed at dosages of 60g or 30g per day for a duration of 28 days, on fat oxidation during a 30-minute steady-state exercise bout in a fasted state. Methods: Healthy adults (n=47, BMI<27 kg/m 2), aged 18 to 55, engaged in a 30-minute exercise test performed at 75% of relative VO2 max, pre- and post-dietary intervention. Over 28 days, participants were randomized to receive daily doses of 30g/day or 60g/day of either CSO or olive oil (OO). Using indirect calorimetry at 10-minute intervals during the exercise tests, fat oxidation in kilocalories per minute was calculated and summarized as area under the curve (AUC) at each time point. The shift in fat burning between pre- and post-intervention tests, were then computed. ANOVA was used to find differences between groups. Results: There were no significant changes in fat kcal/22 mins between all groups (p=0.43). Combining both CSO dosage groups revealed a trend increase in fat kcal/22 mins compared to OO (CSO: 5.89 + or - 4.89 kcals/22 mins, OO: -7.71 + or - 7.32 kcals/22 mins p=0.13). No differences were found between 30g and 60g dosages (p=0.51). Sexes showed a significant difference in change of fat oxidation, with females (8.69 + or - 4.28 kcals/22 mins) exhibiting an increase and males (-9.71 + or - 7.25 kcals/22 mins) a decrease (p=0.04). Change in fat percentage showed no significant differences between CSO and OO groups (p=0.98). Conclusion: These findings suggest that CSO may boost fat oxidation in humans, offering potential benefits for metabolic health.Item Energy metabolism and mechanotransduction in osteoarthritic chondrocytes: targeted metabolic profiling and flux analysis(Montana State University - Bozeman, College of Engineering, 2023) Erdogan, Ayten Ebru; Chairperson, Graduate Committee: Ronald K. June II; This is a manuscript style paper that includes co-authored chapters.Osteoarthritis (OA) is a prevalent and debilitating disease that affects hundreds of millions people worldwide. One of OAs major consequences is the degradation of articular cartilage, leading to joint pain, stiffness, and loss of function. Currently, there is no treatment for OA. The existing interventions are mostly for suppressing the symptoms: physical therapy, anti-inflammatories, and pain management. The last resort is total joint replacement, which has long-term consequences especially for early-onset OA patients. Thus, researchers are focusing on understanding this complex disease and its molecular components to develop better treatments. Chondrocytes, the sole cell type in articular cartilage, play a crucial role in maintaining tissue homeostasis and responding to mechanical stimuli via synthesis of key structural components like collagen. However, the intracellular pathways underlying chondrocyte mechanotransduction are not fully understood, especially those related to central carbon metabolism. This thesis uses 13C isotopic labeling to trace carbon sources and downstream metabolites related to energy metabolism in vitro. Primary human articular chondrocytes from OA patients exposed to labeled glucose and glutamine, and their global and targeted metabolite profiles are assessed. The results show how both glucose and glutamine utilization as carbon sources flows through the TCA cycle. This work also develops a comprehensive model of mammalian carbon metabolism in OA primary human chondrocytes. The model integrates energy metabolism, amino acid synthesis, and transport reactions contributing to Collagen-II and Collagen-VI production. Using flux balance analysis (FBA), trade-offs between Collagen-II and Collagen-VI synthesis are evaluated based on ATP and carbon source requirements under different oxidative stress conditions. Then, these model predictions are presented with experimental data obtained from OA chondrocytes subjected to shear and compressive mechanical stimulation, which can be integrated in the model later on. These data shed new light on metabolism of primary OA chondrocytes and provides insight into potential therapeutic targets for OA intervention.Item An expanded lava creek tuff eruption: re-mapping the Sour Creek Dome, Yellowstone National Park(Montana State University - Bozeman, College of Letters & Science, 2023) Salazar, Raymond Dale; Chairperson, Graduate Committee: Madison MyersThe ~1000 km 3, ~630 ka Lava Creek Tuff is the product of the younger major caldera- forming eruption of the Yellowstone Volcanic Field. It is currently mapped as two ignimbrite units, hot dense flows of ash, gas, and molten material, termed members A and B, with accompanying widespread ashfalls over the western U.S. This view of the Lava Creek Tuff, and its eruption, was complicated when two, visually distinct, ignimbrites were recognized on the Sour Creek dome in Yellowstone National park (Wilson et al., 2018). These visually distinct ignimbrites on the Sour Creek dome were initially mapped as the older (2.08 Ma) Huckleberry Ridge Tuff, however, when dated by U - Pb on zircon and 40Ar/39Ar on sanidine the ignimbrites returned ages analytically indistinguishable from the Lava Creek Tuff (0.631 Ma). In the newly dated ignimbrites, one unit is found as clasts of dense welded tuff withing a lag deposit which is conformably overlain by a second, cliff-forming, densely welded ignimbrite that contains scoria. This study further complicate matters due to the discovery of two additional, previously unrecognized, ignimbrites while mapping on the Sour Creek dome, bringing the total to four ignimbrites. Physical and chemical evidence suggests there were multiple magma bodies tapped during the eruptions. This project broadens our understanding of the four ignimbrites documenting their spatial distribution and source area(s) and determine how they relate geochemically to the established members A and B. This was done through field mapping, thin section examination, and whole-rock and single crystal geochemistry. This resulted in a revised understanding of the Lava Creek Tuff stratigraphy and holds implications for reevaluating the eastern boundary of the Yellowstone Caldera.Item What's the big eel: highlighting the efforts of scientists to explore the scientific process(Montana State University - Bozeman, College of Arts & Architecture, 2023) Grunder, Amanda Katherine; Chairperson, Graduate Committee: Dennis AigBy highlighting the devoted efforts that science requires, science films can create a long-term impression on their audiences. This thesis showcases how the scientific process can create a more trustworthy and believable documentary, even with an audience having an increasing rate of science denial. By highlighting the passionate dedication it takes to conduct the scientific process, documentaries can create an interest in audiences and retain a sense of trust. This method's success is discussed in a variety of different documentaries, including "My Octopus Teacher", "Particle Fever", "The Thin Blue Line", and my related thesis film "The Eel Problem."Item Integrated weed management in pulse crops(Montana State University - Bozeman, College of Agriculture, 2024) Brar, Akamjot Singh; Chairperson, Graduate Committee: Fabian D. Menalled; Lovreet S. Shergill (co-chair); This is a manuscript style paper that includes co-authored chapters.The wheat-fallow rotation remains a predominant cropping system in the US Great Plains, with heavy reliance on chemical control for weed management. This reliance has resulted in problematic weed infestations, necessitating the exploration of additional weed management options. Crop diversification with pulse crops such as chickpeas and fava beans offer expanded weed management options and several agronomic and soil benefits. However, these crops are poor weed competitors due to their slow early-season growth. Early season weed management, primarily through pre-emergence (PRE) herbicides, is crucial but is challenged by a lack of tillage and limited precipitation for herbicide activation in semi-arid regions. These PRE herbicides can also be applied in the fall to facilitate activation, thereby maintaining residual activity for controlling weed emergence and enhancing crop competition in the spring. Another cultural method to enhance competitiveness is early planting, which can provide the crop with a head start by allowing it to emerge before weeds. Field experiments were conducted across Montana in 2022 and 2023 to study the effect of fall-applied herbicides and the integration of fall-applied herbicides and planting dates on weed management in spring-planted pulses. The results demonstrate that fall-applied herbicides provide early-season weed suppression and improve crop establishment, with certain combinations (e.g., pyroxasulfone + flumioxazin, dimethenamid + pendimethalin, carfentrazone + sulfentrazone) offering consistent residual activity throughout the season. However, the efficacy of some of these treatments (e.g., pyroxasulfone, simazine, ethalfluralin, dimethenamid) diminishes later in the season, necessitating a follow-up post-emergence herbicide application to manage late-emerging weeds. Additionally, the thesis explored the integration of fall-applied herbicides and planting dates, revealing that early planting provided an additional 20 (3.5) % reduction in weed biomass by allowing the crop to emerge before major weed species. The integration of herbicides and early planting yielded a substantial increase in crop yield compared to the untreated check, demonstrating the potential of these programs to improve weed management and crop productivity in pulse rotations. The results highlight the importance of integrating chemical and cultural weed management tactics for increasing cropping systems' sustainability by integrating pulses in the US Great Plains.Item Factors associated with elk (Cervus canadensis) distributions during rifle season and individual responses to harvest risk in a prairie environment(Montana State University - Bozeman, College of Letters & Science, 2024) Krieger, Elisabeth Rachelle; Chairperson, Graduate Committee: Jay J. RotellaHunting pressure alters habitat selection of elk and understanding responses to pressure is important for effective population and habitat management. While elk responses to hunting are well-studied in forested and mountainous environments in the western U.S., little is known about elk habitat selection in more open prairie landscapes. Our objectives were to evaluate the effects of landscape and environmental factors on elk habitat selection during the rifle season, assess individual variability, and investigate relationships between selection and harvest risk for male and female elk in two populations: the Custer Forest and Missouri River Breaks in eastern Montana, USA. We also provided management recommendations for habitat characteristics that allowed elk to mitigate exposure to harvest risk (i.e., security habitat) based on where most elk use occurred. We used resource selection function modeling with a use-available design and added random effects to estimate selection patterns for individual elk. Resource selection coefficients indicated that elk generally selected areas with restricted hunter access, rugged terrain, and greater distances from motorized routes with a few notable differences for elk in the Missouri River Breaks. In particular, canopy cover was consistently associated with large increases in relative probability of use. Estimates of individual random coefficients indicated that while elk typically shared the same direction of selection for a given covariate, individuals varied in the strength of these relationships, likely due, in part, to varying exposure to risk. Individual elk increased selection for habitat features that provided security when faced with higher harvest risk (i.e., the proportion of used locations that fell on publicly accessible lands). Our results indicated canopy cover was a particularly important factor associated with elk selection during the rifle season in our prairie landscapes where available cover is relatively limited. The relative importance of other factors varied depending on study area and sex. Based on where most elk use occurred, we recommend managing for security and preferred security areas with canopy cover > or = 28% and > or = 37% in the Custer Forest and > or = 3% and > or = 5% in the Missouri River Breaks, respectively, during the rifle season in these areas and prairie landscapes with similar habitat attributes.Item Shortest common supersequence with applications(Montana State University - Bozeman, College of Engineering, 2024) Chen, Muzhou; Chairperson, Graduate Committee: Binhai ZhuThe shortest common supersequence problem (SCS) is a classical problem that was first studied by Maier in 1978. Recently, some research on the tree-child network inference problem, developed from the inference of phylogenetic networks, which involves a variant of SCS, has been studied. The variant of the shortest common supersequence problem on permutation strings was introduced to solve the tree-child network problem. In this thesis, we first provide the sketch of the proof of the NP-completeness of the SCS problem on the permutation strings from the feedback vertex set problem. From the reduction, we continue analyzing the inapproximability of this new variation. Then, we study the FPT tractability of SCS using different parameters. With the new reduction developed, which corrected and simplified the former reduction provided by Maier from the Vertex Cover problem, we extended the proof to the non-existence of the FPT algorithm parameterized by the number of the inserting positions in the longest input sequence even if it is fixed to be 3. On the other hand, an FPT algorithm parameterized by the solution size has been explored. Furthermore, we extended our proof on the NP-completeness and W[1] hardness of the k-disjoint-SCS problem as another variant of the SCS. Lastly, a new heuristic algorithm has been constructed for practical use by using the concept of maximum increasing substrings, which can be applied to both permutation strings and non-permutation strings. The empirical results show that both algorithms perform similarly in producing the shortest common supersequence, while our algorithm takes longer runtime on average due to the more complex computation during the process.