SHAREOK Repository
Not a member yet
49261 research outputs found
Sort by
Developing strategies to improve educational programs for wildlife forensic laboratory careers
Get PDFThere is a necessity for wildlife forensic programs to uniformly provide a comprehensive curriculum that includes the requirements desired by employers in the growing field of wildlife forensics. Programs need to be created based on societal needs, industry requirements (Avargil et al., 2020), within accreditation standards, and with a broad enough knowledge base for a shifting job market (Hardy et al., 2021). Programs created hastily based on popular demand can result in graduates unprepared for careers (Welsh et al., 2011). Planning programs around how students select classes (Othman et al., 2019) and improving degree roadmaps can result in financial gains (Su et al., 2019). By determining the requirements for the various wildlife forensic careers, wildlife forensic programs can individualize their programs to best prepare wildlife forensic students. The most current entry level job descriptions for Wildlife Forensic Chemist, Geneticist, and Morphologist, were obtained from the world's most prominent laboratory, The National Fish and Wildlife Forensics Laboratory. Course objectives, lessons, and labs from current University of Central Oklahoma degrees were evaluated to see if and how the knowledge, skill, and ability requirements were met. The results were arranged into tables and requirements that were not met or partially met were identified. This project developed strategies in the form of short, middle, and long-term goals that can be implemented to meet all job requirements for the three wildlife forensic careers looked at in this project. The methods of this project could be used as a template for how to evaluate or develop programs that align with job requirements for respective careers. The job requirements in this study could be used as a guide to create wildlife forensic education standards to standardize wildlife forensic programs. The design of this project along with surveys of students, employers, and employees can be used in future projects to evaluate the effectiveness of other programs at meeting job requirements for respective careers
3D finite element modeling of blast wave transmission in human ear from external ear to cochlear hair cells
Get PDFAuditory system dysfunction caused by exposure to blast waves is one of the leading causes of disability among military servicemembers and veterans. While the external and middle ear response to blast overpressures (BOPs) have been characterized experimentally, the inner ear behavior is much more difficult to measure, especially the micro-level cochlear hair cells in the organ of Corti (OC) responsible for converting pressure waves into electrical signals. Recently, computational finite element (FE) models have advanced to predict blast wave transmission from the external ear into the cochlea. However, in published FE models the anatomy of the inner ear is still insufficient. The objective of this study was to develop a 3D FE model of the human ear that included a 3-chambered cochlea to improve inner ear anatomy, validate the model’s results, and simulate the behavior of the OC during blast wave transmission.
The human ear FE model consists of the ear canal, middle ear, and spiral cochlea with 3 chambers (scala vestibuli, scala media, and scala tympani) separated by Reissner’s membrane (RM) and the basilar membrane (BM). The model was run as a coupled fluid-structural analysis in ANSYS. An experimentally recorded blast waveform was applied as input to the entrance of the ear canal, and the model outputs included the ear canal (P1) and cochlear pressures, and the displacements of the tympanic membrane (TM), stapes footplate (SFP), and BM. The results of the model were compared to experimental measurements from blast tests in order to validate the FE model’s results. In addition, a microscale structural model of the OC was developed that used the FE model-derived BM displacement at 16.75 mm from the BM base end as input. This model reported some preliminary results describing the motion of the outer hair cells (OHCs) and hair bundles (HBs).
The FE model of the human ear successfully predicted the middle and inner ear tissue displacements and fluid pressures. The P1 pressure, cochlear pressures, TM displacement, and SFP displacements were validated against blast test results. The incorporation of the 3-chambered cochlea improved the model’s accuracy compared to previous cochlea models used for blast transmission and demonstrated the influence of the RM and scala media chamber on cochlear biomechanics. These results were used to predict the likelihood of auditory injury. In addition, the preliminary results of the OC model showed radial variation in the OHC and HB behavior and indicated some potential mechanisms of sensory hair cell injury.
The FE model reported in this thesis successfully improved the simulation of human cochlear anatomy and was validated against experimental blast measurements. A microscale model of the OC was connected with the full human ear model, giving some preliminary insight into blast-induced OC behavior. Future work with this model will improve the connection between the cochlea model and OC model and apply the FE model of the human ear to hearing loss prediction and the evaluation of earplug effectiveness
What sustains Chinese language learning motivation: a case study of southwestern American high school students
Get PDFThis holistic single-case study aims to investigate the sustained Chinese language learning motivation of American high school students who learn Chinese as a foreign language. The study is guided by the following questions: "What are the factors that contribute to sustained motivation to learn Chinese as a foreign language among American high school students in their third or fourth year of Chinese learning in a Southwestern state in the United States?" and "How are heritage and non-heritage high school students in their third or fourth year of Chinese learning in a Southwestern state in the United States different or similar in their sustained motivation to learn Chinese as a foreign language?" Eleven participants, including 10 high school students enrolled in Chinese 3 and 4 classes and one Chinese teacher, participated in the study. The students completed a demographic survey and two interviews, while the Chinese teacher was interviewed once. Classroom observations were conducted throughout the semester. Data sources included completed surveys, interview transcripts, and classroom observation field notes. The researcher used thematic analysis as an overarching method to identify major themes and conducted constant comparisons to analyze the data. The study identified six major factors contributing to sustained Chinese learning motivation: (a) teacher influence, (b) love of the Chinese language and culture, (c) personal development and advancement, (d) utility, (e) peer influence, and (f) parental influence. The study also found several major similarities and differences in sustained Chinese learning motivation between heritage and non-heritage language learners. This study highlights the significance of recognizing and addressing the unique motivations of both heritage and non-heritage language learners in Chinese language education
Studies in Anthropological Metabolomic and Microbial Approaches
No full textHuman biology is shaped by layers of interacting biomolecules, from genes to proteins and small molecules called metabolites. These molecules are crucial participants in biochemical reactions, representing biological information within and above the genome. Investigating the system of small molecules (the metabolome) offers deep inquiries into the interplay between human health, biology, behavior, and the environment. Anthropological interest in these small molecules is growing, but more work is needed to integrate metabolomics within anthropology. In this spirit, this dissertation applies metabolomics approaches with mass spectrometry to address anthropological questions. Chapter one provides a background over mass spectrometry, metabolomics, and anthropological engagement with these approaches. From there, chapter two directly applies mass spectrometry-based metabolomics to study human fecal metabolomes of individuals practicing varying lifeways from Africa and the Americas, revealing key chemical components to the human gut. Next, chapter three investigates mouse metabolites modulated by gut microbes responding to three high-fiber high-fat diets, revealing personalized health and biological responses to dietary shifts. Chapter four then applies mass spectrometry-based metabolomics to preserved residues found in archaeological contexts by analyzing plant and dietary materials relevant to archaeological communities. We discuss new developed methods to analyze these samples, report plant molecules associated with these samples, and detail plans to make these data publicly available for archaeologists and other scholars to integrate into their analyses, improving results generated from these archaeological samples. Together, these three projects explore novel methods of integrating these metabolomic approaches and data into anthropological investigations of past and present human health, behavior, and biology
Evaluation of Seawater Intrusion using Electrical Resistivity Surveys and Geochemical Measurements in Brazoria County, Texas
Get PDFSeawater intrusion is one of the world's leading causes of groundwater contamination in coastal aquifers. In the United States, relatively little research has been conducted in the Gulf Coast Region bordering the state of Texas, even though the coastal zones of this state have been rendered potentially vulnerable to seawater intrusion. Furthermore, most investigations of saltwater intrusion processes globally have focused on numerical modeling experiments and sand-tank experimentations, which highlight the need to acquire reliable geologic information about an aquifer system, and the potential saltwater-freshwater interfaces present in it. Field investigations from geophysical and geochemical approaches present a valid effort to provide an improved spatial understanding of seawater intrusion in coastal aquifers, and a scientific basis for decision-makers and groundwater stakeholders to take appropriate actions for the benefit of water resources and their direct impact on people’s lives.
This study applies electrical resistivity surveys to image the subsurface in Brazoria County, a site selected by analyzing available salinity data of water wells in Texas. Geophysical measurements were collected by using two transects covering the distance between a zone with wells that displayed high and low TDS in the study area, as well as an additional transect located in the surrounding area of a water well that was sampled for this study. Eight groundwater wells were sampled, and geochemical analyses were employed to calibrate and expand the results obtained with the electrical resistivity tomography (ERT). Geochemical indicators of seawater intrusion, such as elevated levels of SpC, sodium, and chloride concentrations were detected in the study area, especially in the regions closer to the coastline. Resistive and conductive structures were found at depth; therefore, the application of ERT in this study proves to be an effective tool in characterizing the subsurface in this region and assessing seawater intrusion, leading to an improved understanding of the spatial distribution of freshwater and saline water that was unattainable with the previously deployed techniques. Further investigation is recommended to characterize the subsurface in this region by employing ERT in additional locations, counteracting the effects of spatial variability and informing groundwater practitioners more accurately, with the objective of taking appropriate actions to protect and manage water resources
The Price Is Not Right: Grocery Taxation, Race, and Food Security During COVID-19
Get PDFUsing recent data from a national sample of 2.8 million households surveyed by the Household Pulse Survey (HPS) (U.S. Census Bureau 2022), this research examines the relationships across food insecurity, grocery taxes, and race during the COVID-19 pandemic. This research asks: How does a respondent’s household food insecurity differ in states that impose grocery taxes compared to states without grocery taxes? How does a respondent’s food insecurity differ by their race? How do these trends reflect government COVID-19 relief policy during this time? This analysis provides a baseline reporting of factors associated with food insecurity during the Covid-19 pandemic using the most recent HPS data. Overall, 35% of respondents report being food insecure at some point during the pandemic. Using survey-weighted logistic regressions and controlling for background demographic and socio-economic variables, this research finds that food insecurity is higher for respondents living in states with grocery taxes compared to those in states without grocery taxes. As the pandemic progresses, a substantial gap in food insecurity is observed; respondents in states with grocery taxes reported higher food insecurity compared to respondents in states without grocery taxes, net of other effects. This research also finds that food insecurity is a more salient issue for Black respondents; Black households in states with grocery taxes have a 43% predicted probability of reporting current food insecurity compared to 34% for white respondents in states without grocery taxes, net of the other covariates. Grocery taxes and being Black negatively affect food security during the Covid-19 pandemic
Computational study of interactions between DNA bases and single-layer Ti3C2 MXene
Get PDFElectronic DNA sequencing using atomically thin 2D-based nanodevices has recently emerged as the next-generation of DNA sequencing technology. Recent molecular dynamics simulations showed that single-layer Titanium Carbide (Ti3C2) has a great potential for detecting individual DNA bases. In this work, we employ first-principles techniques based on density functional theory (DFT) to quantify the electronic interactions between the four DNA nucleobases (adenine, thymine, guanine, and cytosine) with 2D Ti3C2. Our results showed two distinct interaction mechanisms between DNA nucleobases and Ti3C2, namely, physisorption and chemisorption. Unlike graphene, where the binding energy for physisorption of DNA nucleobases is about 0.5 eV, we observe that the binding energy for physisorption for Ti3C2 is around 0.1 eV. This difference correlates to an increased distance between the nucleobases and the Ti3C2 (∼5.6 Å) compared to graphene (∼3.1 Å), indicating a weaker interaction. Based on these results, other electronic detection mechanisms, such as nanopore sequencing, would be worth exploring for Ti3C2
A self-study in middle school social studies engagement
Get PDFWe live in a time of great challenge and great opportunity. Neoliberal socioeconomic paradigms have become a global norm. Economic and military competition are driving forces on the world stage. Postmodern thinking has cast considerable and justified doubt upon traditional narratives and ideologies. The digital age has connected people, places, things, and ideas in ways that have never before been seen. For a young person who is trying to make sense of it all, authentic humanizing education has never been more necessary. Social studies teachers are uniquely positioned to empower young people to construct meaning and forge connections in a world of nonstop information. Despite the seemingly obvious need for powerful social studies education, like many other social studies teachers, I have experienced profound disinterest and disengagement from my students.
To address student disengagement in social studies classes at my middle school I considered academic literature regarding engagement as a construct, the potential factors that could influence student disengagement, and the pedagogical frameworks and philosophies that might be useful in improving student engagement. I found that modeling my educational practice in the style of Paulo Freire’s (1970) problem-posing education had an altering effect on my perception of my role as a teacher and a positive effect on my relationships with my students and my perceived self-efficacy. I grew to perceive many aspects of American public-education as unhelpful, oppressive, and harmful for students and teachers. My findings implicate problem-posing as a powerful framework for a reconstructed social studies curriculum to address contemporary social issues and create solidarity among all stakeholders in public education
Depositional History and Provenance Analysis of the Permian-Aged Garber Sandstone, Central Oklahoma
Get PDFThe Lower Permian Kungurian (Leonardian) Garber Sandstone records a time of profound climatic and tectonic transition in central Pangea with the collapse of an icehouse climate, inception of Pangean monsoonal circulation, and the terminations of the Wichita, Ouachita, and Arbuckle regional uplifts. The source, transport direction, and environment of deposition of the Garber Sandstone in central Oklahoma remains poorly understood. Previous interpretations of this unit range from deltaic to fluvial to shallow/marginal marine. Regional studies of Late Paleozoic sediment dispersal are limited for the Early Permian due to lack of outcrops within and particularly east of the Midcontinent. To rectify this information gap, this study utilizes six new U-Pb detrital zircon geochronology analyses from the Garber Sandstone supported by sandstone petrography, paleocurrent data, grain size analysis, and outcrop and core-based facies analyses to assess trends in sediment provenance and depositional processes along strike of an approximately 435 km outcrop belt. Facies from core and outcrop observations show a predominance of cross bedded, massive, and ripple and planar laminated sandstone that likely represent a sandy, ephemeral fluvial system. A continental fluvial system is further supported by analysis of a core in the central outcrop belt that exhibits abundant macroscopic and microscopic pedogenic features. The Garber Sandstone is highly quartzose with minor sedimentary and low-grade metamorphic lithic fragments. Detrital zircon analysis suggests Paleoproterozoic (1800-1600 Ma), Mesoproterozoic (1300-925 Ma), and Neoproterozoic (790-570 Ma) age populations are present and are interpreted to represent Yavapai-Mazatzal, Peri-Gondwanan, Grenville, and Appalachian sources. Further, there is very little difference among the sandstone mineralogy or detrital zircon age spectra across the outcrop belt, suggesting a well-mixed, single source fluvial system.
Ultimately, the Ouachita fold and thrust belt and possibly reworked strata from the Arkoma basin are interpreted as the primary source for the Garber Sandstone based on detrital zircon geochronology and sandstone petrography. This is also supported by limited paleocurrent data that indicate transport directions from the southeast. Notably, zircon grains with 1600-1800 Ma ages prove difficult to constrain and may represent a source from the Sabine block to the southeast or Yavapai-Mazatzal provinces to the west. The results of this study bear importance on paleogeographic interpretations and sediment dispersal trends in Oklahoma with broader implications for the Midcontinent during the Early Permian. This study agrees with more recent paleogeographic interpretations that the Permian seas retreated from Oklahoma by the Kungurian producing an arid continental interior and suggests seasonal drainage from the Ouachita highlands to the southeast. This further implies that the Ouachita fold and thrust belt was likely still a highland even as other studies suggest regional uplifts such as the Wichita uplift were subsiding and buried by this time
Selective Hydrodeoxygenation of Biomass-Derived Compounds over Promoted Metal Oxide Catalysts
No full textThe pressing need to address environmental issues has led to a growing demand for cleaner and sustainable energy sources, such as biomass. Lignocellulosic biomass-derived bio-oil offers great potential for producing renewable chemicals and fuels. However, the complex nature of this mixture, characterized by a high oxygen content, makes it unstable and undesirable. Therefore, catalytic upgrading is required to improve its properties and remove unwanted components. In this dissertation, the author will utilize various model compounds to investigate the deoxygenation of biomass on highly active reducible metal oxides like MoO3 and TiO2.
The first part of the dissertation focuses on investigating the selective activation of renewable carboxylic acids using promoted molybdenum oxide (MoO3) to form alcohols and aldehydes. This study used a combination of reaction kinetics, temperature programming reduction (TPR), and X-Ray photoelectron spectroscopy (XPS) to gain insights into the underlying mechanism. The findings suggest that the activity for HDO reaction scales with the concentration of Mo5+ species. Meanwhile, this study explores the effect of adding a small amount of Pt (0.05 wt%.) on the rate of selective deoxygenation. The outcomes demonstrate that adding Pt clusters results in a substantial decrease of 32 kJ/mol in activation energy required for the HDO reaction. Moreover, a kinetic study is performed to enlighten the understanding of the selective deoxygenation of carboxylic acid on promoted MoO3 at mild temperatures, indicating that incorporating Pt clusters over MoO3 shifts the reaction order with respect to hydrogen from 1 to 0.5 at a low partial pressure of pentanoic acid (PA). The inhibition effect of PA and its possible causes are discussed for both MoO3 and 0.05 wt% Pt/MoO3 catalysts.
Furthermore, the rapid dynamic changes in MoO3 upon reduction and under reaction conditions were also investigated. A catalytic kinetic model is developed for redox chemistry on MoO3, which considers the formation of hydrogen bronzes, phase transition, oxidation states, oxygen vacancies, hydrogen splitting and spillover, and oxygen mobility throughout the oxide. A micro-pulse reactor was employed to quantify the number of hydrogen bronzes and oxygen vacancies created after various pretreatments. The effect of hydrogen bronzes on MoO3 for the deoxygenation of pentanoic acid is also investigated.
In the second part of this dissertation, carbon nanotubes were utilized to investigate the location of the active sites involved in the three different chemistries, including furfural, pentanoic acid, and anisole conversion. This novel catalyst was synthesized by depositing two different metals on different ends of the nanotube to decouple if the active sites were created either by promotor effects or short-range interactions between the two components in the bifunctional catalyst system. In all cases, a rapid hydrogen spillover observed across the nanotubes from one metal to another is considered.
Through the end of this dissertation, the conversion of furfural to cyclopentanone is studied, focusing on the role of water, the active sites involved, and the reaction mechanism over various catalyst supports. The study reveals that the selectivity for ring rearrangement versus C-O cleavage over Ru and Pd catalysts supported on TiO2 can be adjusted by controlling the partial pressure of water. Additionally, the location of the active site and crucial kinetic pathways for this rearrangement reaction are discussed by utilizing the ability to synthesize carbon nanotubes with different properties