Browsing 2020- by Title
Now showing 1 - 20 of 2010
Results Per Page
- ItemOpen Access250 years of climate-mediated ecological change in Santa Fe Lake, NM(Colorado State University. Libraries, 2022) Shampain, Anna, author; Baron, Jill, advisor; Leavitt, Peter, committee member; von Fischer, Joe, committee member; Sibold, Jason, committee memberMountain lakes are sensitive indicators of anthropogenically driven global change. Lake sediment records in the western United States have documented increased percent carbon and nitrogen and heightened primary productivity indicative of eutrophication in mountain lakes. Recent paleolimnological studies suggest atmospheric nutrient deposition and warming underlie these changes. We analyzed a short sediment core from Santa Fe Lake, NM, the southernmost subalpine lake in the Rocky Mountain Range to investigate patterns in lake biogeochemical and algal biomarkers since 1747. Lake sediments were dated using 210Pb activities and analyzed for percent C and N, δ13C, δ15N, and algal pigments representative of total biomass, chlorophytes, cryptophytes, diatoms, and other primary producers from Santa Fe Lake. Throughout the 250-year sediment record from Santa Fe Lake, we observed changes in algal community composition alongside biogeochemical alterations. During the cold dry conditions of the Little Ice Age, there were greater proportions of cyanobacteria, diatoms, and sulfur bacteria. Total algal biomass increased under increased warming and climate variability with significant increases in chlorophytes and cryptophytes. Significant rates of change occurred concurrently with increases in regional N deposition in the mid-20th century. C, N, δ13C, δ15N remained relatively stable throughout the record, until the mid-20th century when C and N increased exponentially alongside depletions in δ13C, δ15N. Our results suggest climate-driven algal assemblage changes throughout the record with regional N deposition contributing to contemporary productivity increases. The timing and magnitude of these changes differ from other studied lakes. Our findings highlight the heterogeneity of lakes' responses to changing environmental conditions in the Anthropocene and call attention to the role of climate-induced ecological change in the absence of critical N deposition.
- ItemOpen Access316L stainlesss steel modified via plasma electrolytic oxidation for orthopedic implants(Colorado State University. Libraries, 2022) Michael, James A., II, author; Popat, Ketul C., advisor; Li, Vivan, committee member; Sampath, Walajabad S., committee member316L stainless steel (SS) is widely used biomaterial for implantable devices and is estimated to the base material for 60% of implantable devices. However, one challenge of the material is the inhomogeneity of the surface morphology which may influence the adhesion process of host cells and bacteria. One method to create a uniform surface of 316L SS is plasma electrolytic oxidation (PEO). PEO creates an oxide layer on the outer surface thus changing the surface topography on the microscale. PEO process on SS functions by anodizing the surface via direct current in electrolyte solution. Preliminary research found that a continuous direct current over a time manufactured undesirable samples, to overcome this challenge the use of pulse timings was utilized during fabrication. This research aimed to answer the questions how do PEO modifications effect cellular adhesion and viability, and how do PEO modifications affect bacteria adhesion and viability. PEO modified 316L SS surfaces were characterized and its effects on the adhesion, morphology, and differentiation of adipocyte derived stem cells, along with the adhesion and morphology of Staphylococcus aureus was investigated.
- ItemEmbargo3D localization of cytoskeleton in mouse spermatids using stochastic optical reconstruction microscopy(Colorado State University. Libraries, 2022) Sunny, Reshma, author; Krapf, Diego, advisor; Nikdast, Mahdi, committee member; Prasad, Ashok, committee memberIt is estimated by the World Health Organization that globally 186 million individuals live with infertility. Studies have shown that cause of male infertility is unknown in 30 to 50% of the cases. Over the last several years teratozoospermias have been investigated and have been backtracked to events in spermatogenesis. The development of the acrosome and the manchette, protein and vesicle transport in spermatids, and sperm head shaping are crucial steps in the formation of healthy sperms. The cytoskeleton in spermatids plays a crucial role in shaping the sperm head. The acroplaxome exerts forces on the nucleus and gives the mammalian sperm head its species-specific shape, and also facilitates the proper attachment of the nuclear cap called the acrosome, containing the enzymes required for sperm penetration of the oocyte. The manchette should be intact and formed properly to have shortened diameter as spermatids differentiate so that it can constrict the base of the nucleus to shape the head, and also facilitate the transport of cargo to the base of the cell. Thus as studies have confirmed, the disruption in the organization of the cytoskeleton is a concern for infertility. Hence it is crucial to learn more about the cytoskeletal structures in spermatids. The goal of this thesis is to 3D localize these structures. The major structures we are interested in are the acroplaxome and the manchette. For this, we use a super-resolution microscopy method called Stochastic Optical Reconstruction Microscopy to image spermatid cytoskeleton. Our experiments confirmed the presence of α-tubulin in the manchette and that of F-actin in the manchette and the acroplaxome, as previously observed by researchers with 2D confocal images. We observed that the manchette reduces in diameter and progresses to the caudal portion of the cell at the later steps of differentiation and that the structure forms completely at step 10 and disassembles after step 14.
- ItemOpen AccessA circuitous journey of virus characterization and surveillance in North and Central America(Colorado State University. Libraries, 2023) McMinn, Rebekah J., author; Ebel, Gregory D., advisor; Quackenbush, Sandra, committee member; Brault, Aaron, committee member; Neuwald, Jennifer, committee memberThe burden of ticks and the pathogens they carry is increasing worldwide. Powassan virus (POWV, Flaviviridae: Flavivirus), the only known North American tick-borne flavivirus, is of particular concern due to rising cases and the severe morbidity of human disease. In this dissertation we evaluated the recent emergence of POWV from a culmination of field (chapter 2), in vitro (chapter 3), and in-vivo (chapter 4) studies. In addition, we determined the applicability of a vector-enabled surveillance method (xenosurveillance) in Central America (chapter 5). We first used a genetic approach to evaluate the emergence of lineage II POWV, known as deer tick virus (DTV), in parts of North America where human cases occur. We detected DTV-positive ticks from eight of twenty locations in the northeastern United States with an average infection rate of 1.4%. High-depth whole genome sequencing of eighty-four new and archival POWV and DTV samples allowed us to assess geographic and temporal phylodynamics. We observed both stable infection in the northeastern United States and patterns of geographic dispersal within and between regions. Bayesian skyline analysis demonstrated DTV population expansion over the last fifty years. This is concordant with the documented expansion of Ixodes scapularis tick populations and suggests increasing risk of human exposure as the vector spreads. Finally, we isolated sixteen novel viruses in cell culture and demonstrated limited genetic change after passage, a valuable resource for future studies investigating this emerging virus. We then assessed in vitro phenotypes of POWV on human neuronal cells using 16 genetically diverse isolates obtained from a broad geographic and temporal range. We determined over a 10,000-fold range in peak viral titer and significantly decreased cell mortality for two Midwest DTV isolates, though no clear correlation between in vitro phenotype and geo-temporal characteristics could be made. We then performed whole genome sequencing of virus post neuronal cell passage to identify potential residues of interest. Again, no residues could be linked to phenotype, though several interesting residues with increased frequency post-neuronal cell culture were identified. Based on the significant in vitro diversity observed, we sought to assess pathogenesis and tick transmission phenotypes between isolates. We noted neurological disease in mice in both lineages of POWV, with potential low-virulence strains derived from coastal New York. Additionally, we observed an early neuroinvasion phenotype for a Midwest DTV isolate. The ability to infect I. scapularis ticks was determined by feeding on infected host mice (viremic) and through an artificial infection method. Surprisingly, infection rates in ticks via viremic or artificial infection remained consistent between all five isolates tested, resulting in 12-20% infection rate. Taken together, these data demonstrate potential genotype-independent ability to infect ticks and conversely, strain-dependent differences in pathogenesis. In chapter 5, we evaluated a vector-enabled surveillance method ('xenosurveillance') in rural Guatemala. Surveillance methods that permit rapid detection of circulating pathogens are desperately needed. Xenosurveillance is a novel surveillance approach that takes advantage of mosquito feeding behavior to identify blood-borne pathogens that may be circulating in human and animal hosts. This approach circumvents invasive blood sampling of individuals and results in an abundant sample source derived from both humans and animals. In this study, twenty households from two villages (Los Encuentros and Chiquirines) in rural, southwest Guatemala were enrolled and underwent weekly prospective surveillance for 16 weeks. When febrile illness was reported in a household, recently blood-fed mosquitoes were collected from within dwellings and blood samples taken from each member of the household. Mosquitoes were identified to species and blood sources identified by sequencing. Shotgun metagenomic sequencing was used to identify circulating viruses. Culex pipiens (60.9%) and Aedes aegypti (18.6%) were the most abundant mosquitoes collected. Bloodmeal sources were most commonly human (32.6%) and chicken (31.6%), with various other mammal and avian hosts detected. Several mosquito-specific viruses were detected, including Culex orthophasma virus. Human pathogens were not detected. While more intensive sampling may be needed to detect human pathogens, sampling mosquitoes that feed on humans and domestic animals may prove valuable for monitoring pathogens with zoonotic potential.
- ItemOpen AccessA clonable selenium nanoparticle in action: high resolution localization of FtsZ using electron tomography(Colorado State University. Libraries, 2021) Borgognoni, Kanda, author; Ackerson, Christopher J., advisor; Neilson, James, committee member; Kennan, Alan J., committee member; Tsunoda, Susan, committee memberA meaningful understanding of biochemistry requires that we understand the function of proteins, which is heavily dependent on their structure and location within an organism. As the Resolution Revolution of cryo-electron microscopy gains unprecedented ground largely due to the recent development of commercially available direct electron detectors, energy filters, and high-end computation, thousands of protein structures have been solved at atomic or near-atomic resolution, with the highest resolution structure to date being solved at 1.2 Å. A major challenge that has limited the broad use of cryo-electron tomography (cryo-ET) is locating a protein of interest in an organism, as no commercially available high-contrast markers which can be generated in vivo exist. Herein, we present a breakthrough study which aims to solve this problem by synthesizing high contrast metal nanoparticles labeling desired proteins in situ. We isolated a Glutathione Reductase-like Metalloid Reductase (GRLMR), which can reduce selenite and selenate into selenium nanoparticles (SeNPs), from Pseudomonas moraviensis stanleyae found in the roots of a Se hyperaccumulator Stanleya pinnata, or Desert Princes' Plume. A recombinant variant, denoted as a clonable Selenium NanoParticle (cSeNP), was fused to filamentous temperature sensitive protein Z (FtsZ), and the chimera was expressed in vivo using a T7 expression system in model organism E. coli for a proof-of-concept study. Because the SeNPs biogenically produced are amorphous, they exist in a quasistable state and are composed of polymeric Sen in the form of chains and rings that are constantly breaking and reforming. To stabilize the particles during cellular preservation ex aqua, a disproportionation-like reaction can be done either in vivo or as a post-fixation step to form crystalline metal selenide (MSe) NPs that can withstand the processing liquids used. Thereafter, electron tomography was used to acquire a tilt series that was reconstructed into a tomogram and segmented using IMOD, generating a model representing MSeNPs labeling FtsZ filaments. As such, we have demonstrated the potential of using cSeNP as a high resolution marker for cryo-ET. While our study relied on traditional preservation and embedment techniques, we anticipate that for cells preserved via vitrification, cloned SeNPs can be used without subsequent transformation to MSeNPs, as the amorphous particles are stable in aqueous media. Prospectively, we expect that clonable nanoparticle technology will revolutionize cryo-ET, allowing us to localize proteins in vivo at high resolution while maintaining organism viability through metal immobilization. Furthermore, this technique can be expanded to other imaging modalities, such as light microscopy and X-ray tomography, through the discovery and engineering of other clonable nanoparticles.
- ItemOpen AccessA combined classification and queuing system optimization approach for enhanced battery system maintainability(Colorado State University. Libraries, 2022) Pirani, Badruddin, author; Cale, James, advisor; Simske, Steven, committee member; Miller, Erika, committee member; Keller, Josh, committee memberBattery systems are used as critical power sources in a wide variety of advanced platforms (e.g., ships, submersibles, aircraft). These platforms undergo unique and extreme mission profiles that necessitate high reliability and maintainability. Battery system failures and non-optimal maintenance strategies have a significant impact on total fleet lifecycle costs and operational capability. Previous research has applied various approaches to improve battery system reliability and maintainability. Machine learning methodologies have applied data-driven and physics-based approaches to model battery decay and predict battery state-of-health, estimation of battery state-of-charge, and prediction of future performance. Queuing theory has been used to optimize battery charging resources ensure service and minimize cost. However, these approaches do not focus on pre-acceptance reliability improvements or platform operational requirements. This research introduces a two-faceted approach for enhancing the overall maintainability of platforms with battery systems as critical components. The first facet is the implementation of an advanced inspection and classification methodology for automating the acceptance/rejection decision for batteries prior to entering service. The purpose of this "pre-screening" step is to increase the reliability of batteries in service prior to deployment. The second facet of the proposed approach is the optimization of several critical maintenance plan design attributes for battery systems. Together, the approach seeks to simultaneously enhance both aspects of maintainability (inherent reliability and cost-effectiveness) for battery systems, with the goal of decreasing total lifecycle cost and increasing operational availability.
- ItemOpen AccessA comparative analysis of wetland and riparian vegetation on Bureau of Land Management land in the western US(Colorado State University. Libraries, 2023) Binck, Elin, author; Sueltenfuss, Jeremy, advisor; Reynolds, Lindsay, committee member; Smith, Melinda, committee member; Havrilla, Caroline, committee memberIn 2011, the BLM deployed its first of three Assessment, Inventory, and Monitoring (AIM) programs as a large-scale, standardized ecological monitoring effort across the agency's land. The first two programs, known as Terrestrial AIM and Lotic AIM, were designed to sample all terrestrial and river ecosystems throughout the landscape. In 2019, the agency piloted its third AIM program, specifically targeting riparian areas and wetlands. This study addressed two main questions: 1) How do wetland and riparian areas sampled with the Terrestrial AIM program compare to those sampled with the Riparian and Wetland (R&W) AIM program, and 2) What are the drivers of plant community composition of the wetlands and riparian areas sampled on BLM land? I developed a set of criteria to identify sites sampled with Terrestrial AIM that had characteristics of wetlands or riparian areas. I then compared vegetation cover, floristic quality metrics, and species composition using nonmetric multidimensional scaling (NMDS) to those sites sampled with R&W AIM. R&W AIM sites had much greater foliar cover, hydrophytic species cover, and perennial cover, but Terrestrial sites had slightly higher floristic metric values. I similarly analyzed the R&W sites on their own, incorporating wetland-specific data that is collected with the new program. I found that sites that met the criteria to be classified as wetlands in the Terrestrial data were a distinct population from the sites sampled with R&W AIM. The main drivers of plant community composition among sites sampled with R&W AIM were elevation and the distribution of surface water, but impacts of grazing were also apparent. All sites assessed by both AIM programs had floristic quality metrics characteristic of highly impacted wetland systems. This study indicates the value of the new R&W AIM program for its ability to perform wetland-specific ecological monitoring, provide valuable data on the health of wetlands, and provide baseline condition that can help guide land management practices into the future.
- ItemOpen AccessA comparison of suicide loss and non-suicide loss: the impact on family communication and affect(Colorado State University. Libraries, 2023) Belzil, Eva, author; Quirk, Kelley, advisor; Ortega, Lilyana, committee member; Willis, Danielle, committee memberSuicide loss and non-suicide loss impact thousands of people globally each year. Literature to date has identified ways suicide-loss can impact individuals and families in unique ways but has not indicated what specific aspects of family function are impacted for suicide-bereaved family members. Further, it is unclear whether family members can turn to each other to provide and receive support after their loss. The purpose of this study was to understand how suicide loss of a family member impacts individuals when compared to suicide loss of a non-family member. Additionally, this study aimed to understand how suicide loss of a family member impacts family dynamics on specific levels of communication, affect expression, affect connection, and general family functioning when compared to non-suicide family member loss. Perceived familial support was predicted to moderate the relationship between type of loss and these family function variables. Participants (N = 174) filled out 4 self-report measures that assessed family function prior to their loss, grief experiences, family communication, affect expression, affect connection, and family function after their loss. An independent samples t-test and a hierarchical multiple regression with a moderation analysis were run to examine the relationships between the predictor and outcome variables described above. When compared to individuals who experienced a non-family member suicide loss, individuals who experienced family member suicide loss reported more intense grief experiences (p = .03) but did not report significantly different family function. When compared to non-suicide family member loss, individuals who lost a family member to suicide reported lower family affect connection (p < .05) and lower family affect connection (p < .05), but did not report significantly different family function or family communication. Perceived familial support did not moderate these main effects.
- ItemOpen AccessA compiler for hierarchical task-based programming on distributed-memory(Colorado State University. Libraries, 2022) Dubois, Alexandre, author; Pouchet, Louis-Noël, advisor; Rajopadhye, Sanjay, committee member; Wilson, James, committee memberToday, computation intensive applications are run on heterogeneous clusters of machines and use the Message Passing Interface (MPI), which provides a library interface for message-passing between non-shared memory computational resources but comes at a high application development cost. Task-based programming, such as the Concurrent Collection (CnC) model, makes parallelism implicit by only describing task dependencies. This model has recently been extended to model programs with a hierarchical task-based representation, which allows to view tasks at different levels of decomposition, allowing to dispatch tasks of different level optimally to the different available architectures. This thesis main work was to design an algorithm following a graph-based approach to transform a restricted class of single-level regular kernel to a two-level representation in the CnC model extended with hierarchical concepts. This transformation will alleviate performance boost by reducing communication cost and allowing the use of optimized tasks implementation at a coarse level. After describing the CnC programming model concepts, the structure of the proposed graph based tiling algorithm will be developed. Then, the compiler implementing this algorithm on an Intermediate Representation representing a CnC program and generating a C++ version of the kernel using a new hierarchical CnC runtime. Finally, the overhead of this runtime on a shared memory system for a 3D synthetic benchmark representing a classic linear-algebra dependency pattern. This characterization is done to help the user choose the target volume of tasks tile that has to be given as input of the tiling algorithm. The main recommendation is to target a minimization of the number of super- tasks in the runtime while keeping the number of sub-tasks in every super-task under the order of 10000 sub-tasks.
- ItemOpen AccessA comprehensive approach to modeling musculoskeletal aging and injury: an emphasis on Nrf2-related pathogenesis(Colorado State University. Libraries, 2021) Andrie, Kendra M., author; Santangelo, Kelly S., advisor; Hamilton, Karyn, committee member; Goodrich, Laurie, committee member; Podell, Brendan, committee member; Muñoz Gutiérrez, Juan, committee member; Miller, Benjamin, committee memberOsteoarthritis (OA) is a degenerative joint disease that affects over 730 million people globally, over 30 million Americans, and is the leading cause of disability in adults. The underlying pathogenesis is multifactorial and largely undetermined, with a variety of cellular pathways and risk factors contributing to disease onset and progression. The crux of this work is that downregulation in nuclear factor erythroid-2 related factor-2 (Nrf2)-signaling in musculoskeletal tissue serves as a central driver for persistent low-grade inflammation, dysregulation of redox homeostasis, mitochondrial dysfunction, and protein dyshomeostasis, all of which contribute to OA progression. To explore the role of this pathway in OA, we utilized the Hartley OA-prone guinea pig model, which develops naturally occurring idiopathic disease with pathology that mimics human disease. My global hypothesis is supported by preliminary data that demonstrates that aging Hartley guinea pig knee joint tissues have decreased expression of Nrf2 mRNA and protein, which coincides with disease onset and remains decreased throughout OA progression. We investigated the utility of a novel nutraceutical and Nrf2-activator in delaying both the onset and progression of idiopathic OA in this model. The ultimate goal of this work is to (1) identify key molecular pathways involved in the etiopathogenesis of OA, with a particular focus on the contribution of the Nrf2 pathway; (2) investigate the utility of a novel nutraceutical and Nrf2-activator in delaying the onset and/or progression of OA in the Hartley guinea pig, and (3) examine the effects of Nrf2-activation on long bone strength. The inclusion of a musculoskeletal condition beyond OA was also pursued; as such, the clinical and histologic manifestations of a novel rectus femoris myotendinous junction injury model was characterized in rats. Ultimately, this work seeks to advance the understanding of musculoskeletal aging and injury through the analysis of key structural and functional outcome measures to further develop appropriate therapeutic targets for disease prevention and treatment.
- ItemOpen AccessA comprehensive compendium of Arabidopsis RNA-seq data(Colorado State University. Libraries, 2020) Halladay, Gareth A., author; Ben-Hur, Asa, advisor; Chitsaz, Hamidreza, committee member; Reddy, Anireddy, committee memberIn the last fifteen years, the amount of publicly available genomic sequencing data has doubled every few months. Analyzing large collections of RNA-seq datasets can provide insights that are not available when analyzing data from single experiments. There are barriers towards such analyses: combining processed data is challenging because varying methods for processing data make it difficult to compare data across studies; combining data in raw form is challenging because of the resources needed to process the data. Multiple RNA-seq compendiums, which are curated sets of RNA-seq data that have been pre-processed in a uniform fashion, exist; however, there is no such resource in plants. We created a comprehensive compendium for Arabidopsis thaliana using a pipeline based on Snakemake. We downloaded over 80 Arabidopsis studies from the Sequence Read Archive. Through a strict set of criteria, we chose 35 studies containing a total of 700 biological replicates, with a focus on the response of different Arabidopsis tissues to a variety of stresses. In order to make the studies comparable, we hand-curated the metadata, pre-processed and analyzed each sample using our pipeline. We performed exploratory analysis on the samples in our compendium for quality control, and to identify biologically distinct subgroups, using PCA and t-SNE. We discuss the differences between these two methods and show that the data separates primarily by tissue type, and to a lesser extent, by the type of stress. We identified treatment conditions for each study and generated three lists: differentially expressed genes, differentially expressed introns, and genes that were differentially expressed under multiple conditions. We then visually analyzed these groups, looking for overarching patterns within the data, finding around a thousand genes that participate in stress response across tissues and stresses.
- ItemOpen AccessA conductor's analysis: John Mackey's Wine-dark sea: symphony for band(Colorado State University. Libraries, 2020) Weber, Shannon Denise, author; Phillips, Rebecca, advisor; Grapes, K. Dawn, committee member; Kenney, Wes, committee member; Pedrós-Gascón, Antonio, committee memberThis thesis provides a study of the composer John Mackey and his music. In the last twelve years, Mackey has become internationally renowned and one of the most widely performed composers in the band world. Mackey has received numerous awards and honors for his musical contributions. His unique compositional style is distinguishable in his works regardless of the genre. Audiences, conductors, and performers alike continue to find enjoyment in his music due to his creative, rhythmic, and unique scoring for winds and percussion. This document includes biographical information on the composer, provides insight into his compositional style, and thoroughly analyzes the symphony for band, Wine-Dark Sea. Wine- Dark Sea was commissioned in 2014 by Jerry Junkin and the University of Texas Wind Ensemble, in celebration of the 100th anniversary of the Sarah and Ernest Butler School of Music. The symphony is a programmatic piece that tells the story of Odysseus, Homer's hero from The Odyssey, through three exciting and dramatic movements. Distinctive characteristics of this piece include Mackey's unique use of meter changes, extended techniques in winds and percussion, and recurring programmatic themes. Wine-Dark Sea is Mackey's longest work to date, one of his most challenging works for performers and conductor, and is especially captivating for the audience.
- ItemOpen AccessA conductors guide to the use of ensemble pedaling and acoustic recreation of electronic delay processing in the wind band music of Viet Cuong(Colorado State University. Libraries, 2023) Pouncey, Benjamin Allen, author; Phillips, Rebecca L., advisor; Grapes, K. Dawn, committee member; Taylor, James, committee member; Doe, Sue, committee memberThe purpose of this thesis is to provide a conductor's analysis of two unique orchestration techniques utilized in Viet Cuong's wind band music. Viet Cuong (b. 1990) is an award–winning contemporary American composer whose eclectic sound has been described as "alluring" and "wildly inventive" by The New York Times. Two approaches to orchestration have been identified by the composer as distinctive elements of his compositional voice: ensemble pedaling, and the acoustic recreation of electronic delay processing. Sound and Smoke (2011) is Cuong's earliest available work for wind band and exemplifies early application of these techniques. Over the course of his career, Cuong has continued to employ and develop these approaches in select works, including Vital Sines (2022). Therefore, this document provides detailed examination of ensemble pedaling, and the acoustic recreation of electronic delay processing appearing in Cuong's Sound and Smoke, with select examples provided from Vital Sines to serve as a comparison of these techniques in the composer's recent body of work. The research conducted was completed concurrently with the Colorado State University Wind Symphony's performance preparation of Sound and Smoke in the 2023 spring semester. The information presented serves as a resource for the preparation and performance of Viet Cuong's music for wind band.
- ItemOpen AccessA critical analysis of participatory research in the social sciences(Colorado State University. Libraries, 2022) Russell, Gregory, author; Champ, Joseph, advisor; Arthur, Tori, committee member; Carcasson, Martin, committee member; Flores, David, committee member; Humphrey, Michael, committee memberIn this dissertation, I put forward ethical, methodological, and epistemological reasons that warrant the presence of participants in the appraisal of social scientific research products. I discuss the nature of appraisal through Wittgenstein's linguistic philosophy and use it to support the claim that participatory research holds the capacity to improve formalized appraisal processes in cultural research. Extending the critique into a consideration of Western and Indigenous epistemologies, I attempt to deconstruct the ways in which Western academic research, specifically social scientific research, perpetrates colonialism and how, through participatory research, social scientific research practices might begin the process of decolonization. I then discuss how descriptive analytic techniques can make participant appraisal viable in academic contexts by showing how participatory strategies can license non-immersive data-collection methods, e.g., general interview-based research, in ways that are typically associated with those that are immersive, e.g., participant-observation.
- ItemEmbargoA decolonial analysis of peace education in India and Pakistan(Colorado State University. Libraries, 2023) Jalal, Runeela, author; Jennings, Louise, advisor; Timpson, William, committee member; Archibeque-Engle, Shannon, committee member; Ehlers-Zavala, Fabiola, committee memberThis dissertation investigates the current state of peace pedagogy in formal and informal educational platforms in India and Pakistan. The overarching goal is to amass pedagogical strategies for peace teaching by understanding the aspirations of peace as understood by the local wisdom in the spirit of decolonial educational approaches. The socio-political postcolonial conflict scene is understood through the theories of Structural Violence (Galtung, 1969) and Cascades of Violence (Braithwaite and D'Costa. 2018). It was important as India and Pakistan were colonized for a century and the postcolonial conflict climate has its distinctive nature. There is considerable research done to explain the postcolonial repercussions on a society entailing violence, conflicts, and nationalism and how such negative impacts trickle down into the education system in India and Pakistan. Additionally, The Theory of Positive Psychology (Seligman, 1998) defines the parameters of decolonized peace pedagogy for analyzing educational documents and the work of self-motivated peace practitioners working with non-governmental organizations (NGOs). After this foundational understanding is developed for this research study in Chapter 1, Chapters 2-4 explore the possible implementation of peace pedagogy in education in India and Pakistan through three interrelated articles. The first article is a systematic review of the peace pedagogy literature in postcolonial lands around the world. These regions mainly are located in the Global South which includes Africa, the Middle East, and Asia. The second article takes a closer look at the place of peace pedagogy in existing formal/informal educational platforms through document analysis of policy papers, college programs, and a few non-governmental organizations (NGOs) in Pakistan and India. The third article focuses on the efforts of NGOs at the grassroots level through phenomenological interviews with peace practitioners in Pakistan and India; this study focuses on how these practitioners engage with local communities to make meaning of peace at the local level and devise a suitable peace pedagogy to continue their mission of peace education. Chapter 5 addresses implications of this research study by contributing to the decolonial ways of building knowledge for implementing peace pedagogy in postcolonial lands specifically India and Pakistan. In doing so, Chapter 5 summarizes comparative knowledge through a literature review of peace pedagogy in postcolonial lands around the world and India and Pakistan. This helped identifying gaps which prevent linear implementation of peace pedagogy from early education up to graduate level in India and Pakistan, thus, compromising the objectives of establishing peace. Recommendations for the education system mainly through the lessons learned by the self-motivated peace educators and activists are put forward for considerations.
- ItemOpen AccessA defense of emotions in evolutionary epistemology(Colorado State University. Libraries, 2023) Van, Minh-Tu, author; Rice, Collin, advisor; Kasser, Jeffrey, committee member; Snodgrass, Jeffrey, committee memberCurrent literature in evolutionary epistemology places a kind of epistemic 'rationality', guided by evolution, as the primary consideration or rationale that directs whether and how we acquire knowledge. Foundational works by the likes of Donald Campbell, Konrad Lorenz, and Sir Karl Popper paved the grounds of evolutionary epistemology by prioritizing natural selection's role within theories of knowledge. By recognizing and understanding the significance of humans' niche within the biological world, it better informs us of the aims of evolutionary epistemology. My thesis aims to incorporate emotions in the understanding and development of evolutionary epistemology. My arguments stem from the idea that emotions are an innate and biological response that have an epistemically significant evolutionary history while also concurrently conferring epistemic advantages. With much of the current discussion focused on evolutionary 'rationality' sans emotion, there is much left to be desired in evolutionary epistemology: I believe evolutionary epistemology is missing an evaluation and incorporation of our emotional systems that shape and influence epistemic aims. While evolutionary epistemologists allude to emotions' significance and relevance through other causal mechanisms, there is little discussion of how emotions explicitly affect and interact with our epistemic processes. The overall aim of my thesis is to stress the epistemic contribution that emotions would have to the current developments within evolutionary epistemology and its fittingness within the scope of evolutionary epistemology's aims as currently construed. I first summarize evolutionary epistemology using the works of Campbell, Lorenz, and Popper and explicate what evolutionary 'rationality' entails. Then, I explore some epistemic roles emotions play within important features extrapolated from an evolutionary 'rationality': epistemic fallibility and epistemic creativity. I argue that evolutionary epistemology benefits from an investigation and application of emotions to these features because their role reinforces the same aims that evolutionary epistemology strive to achieve. To wrap things up, I lay out implications and future directions of accepting my defense. I ultimately contend that a more serious consideration of emotions within evolutionary epistemology would only elucidate a fuller comprehension of our naturalized knowledge; not only will we learn more about what human knowledge is construed as, but we will also learn more about how the construction of knowledge, for and by evolved humans, ought to be produced.
- ItemOpen AccessA direct-reading particle sizer (DRPS) with elemental composition analysis(Colorado State University. Libraries, 2023) Sipich, James Robert, author; Yalin, Azer P., advisor; Volckens, John, committee member; L'Orange, Christian, committee member; Carter, Ellison, committee memberThere is a lack of aerosol measurement technology capable of quantifying, in real-time, the size, concentration, and composition of large inhalable particles with an aerodynamic diameter larger than 20 µm. Aerosols of this size penetrate the upper respiratory system upon inhalation and present surface contamination hazards upon settling. The ability to obtain information on the composition of airborne particles is necessary to identify and control risks from exposure to potentially toxic materials, especially in the workplace. The objective of this work was to validate the performance of a prototype Direct-Reading Particle Sizer (DRPS) that counts and sizes particles via time-of-flight light scattering and determines single-particle elemental composition via Laser-Induced Breakdown Spectroscopy (LIBS). Counting, sizing, and spectral measurement efficiency were evaluated using test aerosols of multiple materials with diameters between 25 and 125 µm. Particle sizing results showed good agreement with optical microscopy images. The relationship between the median aerodynamic diameters measured by the DRPS time-of-flight and optical microscopy was linear (Deming regression slope of 0.998) and strongly correlated (r2 > 0.999). The mean absolute difference between the median aerodynamic diameters measured by the instrument by time-of-flight and microscopy over all 8 test aerosol types was 0.9 µm with a mean difference in interquartile range of 1.9 µm. The prototype sensor uses an optical triggering system and pulsed Nd:YAG laser to generate a microplasma and ablate falling particles. Particle composition is determined based on collected emission spectra using a real-time material classification algorithm. The accuracy of the composition determinations was validated with a set of 1480 experimental spectra from four different aerosol test materials. We have studied the effects of varying detection thresholds and find operating conditions with good agreement to truth values (F1 score ≥ 0.9). Details of the analysis method, including subtracting the spectral contribution from the air plasma, are discussed. The time-of-flight aerodynamic diameter measurement and LIBS elemental analysis capabilities demonstrated by the DRPS provide a system capable of both counting, sizing, and identifying the composition of large inhalable particles.
- ItemOpen AccessA disobedient mediation(Colorado State University. Libraries, 2021) Bagdon, Andrea, author; Osborne, Erika, advisor; Bernagozzi, Jason, committee member; Ryan, Ajean, committee member; Little, Ann, committee memberHistorically within the canon of art, specifically painting, the female form and ultimately female identity was understood in binary terms as being an opposite of the heroic male, conveyed as a commoditized trope of the feminine. There was a disruption to the canon of art in 1968 with the invention of the handheld Sony Portapak camcorder. Many female artists adapted video into their artmaking practice for its ability to become an effective communication medium. In its infancy, the medium of video was not yet dominated by male artists and was not taught in most art institutions. Thus, it represented a medium untainted by the baggage of art history. As a result, experimental video became a feminist medium which offered an alternative form of mediation to subvert the patriarchal artistic canon. Artists have the potential to be researchers of perception and Art can become an agent of mediation to breakdown subjective social orders that cloud our consciousness. My work aims to decode and expose the abstracted systems of femininity and the domestic by using the image processing mediums of video and paint. My paintings and videos unveil multiple emotional states from the same female-identifying psyche in order to examine intimate scenes of self-conflict which have been brought on by obsessive cultural programming. By using uncomfortable representations of the domestic and the figure I also intend to highlight the psychological trauma and disrupt the patriarchal lens that is inherent within the canon of art.
- ItemOpen AccessA fandom framework: critical digital media literacy in first-year composition curriculum(Colorado State University. Libraries, 2023) Wigginton, Brook, author; Amidon, Timothy R., advisor; Szymanski, Erika, committee member; Diffrient, David Scott, committee memberCritical digital media literacy is an important factor in everyday life and in academia, but it has failed to gain momentum in first-year writing studies as a necessary literacy for students to develop. A comparative analysis of two first-year composition programs and the inclusion of autoethnographic examples is done to explore how critical digital media literacy is valued in current curriculum and to showcase its potential. Findings indicate that, while critical digital literacy is, in fact, a major part of first-year composition curriculum, it is not overtly named as such. The power in naming the literacies composition instructors expect students to enact and learn should not be underestimated, and composition scholars must renegotiate how we teach students to navigate our increasingly digitally mediated world. An example of how a fandom framework might name and develop those literacies is offered.
- ItemOpen AccessA fourth-order finite volume algorithm with adaptive mesh refinement in space and time for multi-fluid plasma modeling(Colorado State University. Libraries, 2022) Polak, Scott E., author; Gao, Xinfeng, advisor; Guzik, Stephen, committee member; Tomasel, Fernando, committee member; Ghosh, Debojyoti, committee member; Bangerth, Wolfgang, committee memberImproving our fundamental understanding of plasma physics using numerical methods is pivotal to the advancement of science and the continual development of cutting-edge technologies such as nuclear fusion reactions for energy production or the manufacturing of microelectronic devices. An elaborate and accurate approach to modeling plasmas using computational fluid dynamics (CFD) is the multi-fluid method, where the full set of fluid mechanics equations are solved for each species in the plasma simultaneously with Maxwell's equations in a coupled fashion. Nevertheless, multi-fluid plasma modeling is inherently multiscale and multiphysics, presenting significant numerical and mathematical stiffness. This research aims to develop an efficient and accurate multi-fluid plasma model using higher-order, finite-volume, solution-adaptive numerical methods. The algorithm developed herein is verified to be fourth-order accurate for electromagnetic simulations as well as those involving fully-coupled, multi-fluid plasma physics. The solutions to common plasma test problems obtained by the algorithm are validated against exact solutions and results from literature. The algorithm is shown to be robust and stable in the presence of complex solution topology and discontinuities, such as shocks and steep gradients. The optimizations in spatial discretization provided by the fourth-order algorithm and adaptive mesh refinement are demonstrated to improve the solution time by a factor of 10 compared to lower-order methods on fixed-grid meshes. This research produces an advanced, multi-fluid plasma modeling framework which allows for studying complex, realistic plasmas involving collisions and practical geometries.