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Environmental Health Inequalities and Discriminatory Zoning: Identifying Systemic Barriers for Environmental Health Equity through Community-Engaged Research
Get PDFEnvironmental justice research has exposed that environmental health inequalities persist for historically redlined communities due to proximity to heavy industrial areas. Communities of color are systematically exposed to air pollution due to structural environmental inequalities. Disparate exposure to legacy pollution is often overlooked as a key contributor of racial health disparities. The underlying historical mechanisms and systemic barriers that perpetuate environmental health injustices have been less identified in critical environmental justice research including how to confront state complicity. I use historical archives, community reports, public health research, environmental data, media articles, industry complaint documentation, and other government documents as primary data sources supplemented with purposive, semi-structured interviews with state legislators, city council leadership, the municipal planning department, and the county health department to identify systemic barriers for environmental health equity. I find that historic processes of racial residential segregation imbedded structural environmental inequalities within neighborhoods, and institutional inaction, industrial prioritization, regulatory gaslighting, and discriminatory negligence of zoning conditions are systemic obstructions to environmental justice. My findings are critical for implementing existing federal civil rights protections, developing environmental-justice based state policies, and enforcing current ordinances for industrial areas adjacent to communities of color to protect environmental health
Quantitative assessment of barrel wear from solid copper bullets
Get PDFForensic firearm analysis is based on the principle that firearms impart individual characteristics on bullets and cartridge cases during the firing process, and these individual characteristics can be used to trace a bullet or cartridge case back to the firearm that shot it. For bullets, these characteristics are created by the features inside the barrel. However, these features are subject to change and wear, and this can lead to the inability to identify the firearm that shot a specific bullet. There are many ammunition types on the market, and each type may affect barrel features differently. Literature in the field primarily focuses on the effect of conventional ammunition (i.e., jacketed lead core). One study has been conducted on solid copper bullets, and it indicates that they may have a greater effect on barrel individual characteristics than conventional ammunition. The goal of this research was to determine how solid copper bullets affect barrel rifling characteristics after the successive firing of 500 rounds through a new Glock 19 Gen 5 with a Glock Marksman Barrel. From the 500 bullets, 68 were collected for further analysis. The first ten and last ten bullets were used to profile the barrel characteristics at the beginning and end of the study while every tenth bullet was collected to track any changes in the features. Three-dimensional scans of the land engraved areas (LEAs) were generated using the Cadre Forensics Versa system. Cadre Forensics' implementation of the Congruent Matching Profile Segments algorithm was used to compare the depths of the LEAs. The data were analyzed using the Kwiatkowski-Phillips-Schmidt-Shin time series test, and it showed that the data exhibit a significant decreasing trend. Based on the algorithm scores and visual examinations of the LEA scans and depth profiles, this study demonstrates that solid copper bullets have a significant effect on the individual characteristics within firearm barrels
SUSTAINABLE 3D PRINTED COMPOSITES WITH TUNABLE PROPERTIES AND FUNCTIONAL MICROSTRUCTURES
Get PDFThe environmental impact of petroleum-based plastics has prompted the search for eco-friendly alternatives. Nature-based sustainable materials emerge as compelling substitutes, given their abundance, renewability, biocompatibility, and biodegradability, effectively addressing both environmental and health risks associated with petroleum-based plastics. Recent advances in green biocomposites from plant-derived fiber and crop-derived matrix have stimulated interests in developing engineering-grade and multifunctional materials for additive manufacturing (AM). Direct ink writing (DIW) is an AM technique that enables the customized and precision fabrication of composites with enhanced mechanical properties through microstructural control.
This dissertation focuses on developing 3D printable, recyclable, biodegradable, and functional advanced composites to mitigate the environmental and health hazards linked with petroleum-based plastics. The composite material is derived from amylopectin-rich corn starch and cellulose fibers sourced from corn products and waste. We leveraged a thermally activated gelatinization process of amylopectin molecules to achieve optimal rheological properties of the corn-based composite for 3D printability in DIW. The process utilized the thermal treatment effect on hydrogen bonding formation among amylopectin molecules as well as between amylopectin and cellulose fibers interfaces, thereby enhancing mechanical robustness. The process-structure-property relationships revealed tunable mechanical properties up to 3.3-fold in the printed specimens. Furthermore, recyclability tests demonstrated stable mechanical performance of the 3D printed specimens over 10 cycles compared to pristine samples.
Additionally, we introduced a process-microstructure guided manufacturing approach for fabricating three-dimensional porous structures with hierarchical porosity for application in emerging fields like tissue engineering, bone scaffold, and drug delivery due to their distinctive porosity-driven functional properties. By harnessing the degree of amylopectin gelatinization coupled with 3D printing, we attained precise control over pore size at multiple length scales (macro, micro, and nano). Macropores are engineered via printing path design, while degree of gelatinization governs micro and nanopores formation. process-microstructure relationships demonstrated up to 2.3-fold control over micropores and over 3-fold for nanopores. The novel approaches reported in this dissertation offer opportunities to achieve tailored porosity at macro, micro, and nano scales within composite microstructure. These composites, derived solely from biomass and waste, represent a novel class of additively manufacturable sustainable materials that underscore the potential for replacing petroleum-based plastic, marking a significant stride towards sustainable manufacturing practices. With the rising demand for eco-friendly solutions, these natural material-based composites offer compelling alternatives with diverse applications across advanced engineering and biomedical fields
Transient Brain-Wide Co-Activation Patterns in Infant Resting State Electroencephalography
No full textThis study investigates the temporal brain dynamics in resting-state infant electroencephalography (EEG) by utilizing cortical co-activation patterns (cCAPs). Analyzing data from 49 infants in a longitudinal study, k-means clustering was applied on source level EEG data to reveal cCAPs which had short-lived lifetimes, recurrent and structured transitions, and unique spatial arrangements. These cCAPs described spontaneous brain activity as transitions between states of increasing levels of whole-brain activation.
Additionally, the temporal dynamics revealed that the cCAPs representing states of high activation (whole-brain activity above the mean level of activation) were rare, whereas cCAPs representing brain states below the mean level of activation persisted for the majority of the time. Linear mixed effect models (LMEs) were used to examine the effect of infant age. In response to increasing infant age, the occurrence rate increased while the lifetime and normalized magnitude of activation decreased. Interestingly, the high activation cCAPs started off as rare events yet as age increased their occurrence became more common.
The temporal and transitional characteristics of identified cCAPs in this study mirror prior results found in adults, indicating, firstly, a developmental continuity in brain activity organization from infancy to adulthood and, secondly, the ability of cCAP-based analysis to detect such continuities. The consistency of these findings across adult and infant age groups and their sensitivity to differences in infant age may prove useful in understanding neurodevelopmental trajectories and identifying biomarkers of typical and atypical infant neuropsychological development
Self As Praxis: Centering Teacher Identity in Instructional Practices in the Secondary Science Classroom
Get PDFThe adoption of Next Generation Science Standards (NGSS) and NGSS-like standards necessitates significantly different ways of thinking about K-12 science instruction as well as corresponding instructional approaches to successfully implement the standards. The general stance of the science education community appears to be that, ideally, all teachers will use a research-based constructivist pedagogical approach (i.e., three-dimensional instruction). However, to make this change to constructivist instructional practice and move beyond hypothetical teacher use requires a paradigm shift in how teachers choose to teach. That educators will embrace constructivist epistemology associated with the NGSS is taken as a foregone conclusion. Teachers play an invisible role in the foundational and supporting literature for NGSS and three-dimensional pedagogy, where the hypothetical teacher is addressed only in terms of what practices they need to adopt and what support to provide them. Expectations of teachers’ pedagogical choices in science largely preclude consideration of the complexity and diversity of teachers’ identities.
Teachers enact and negotiate their identities in the daily, ongoing classroom-level experiences, not just in their initial development of those identities. To better understand the impact of those identity negotiations on teachers’ instructional choices requires greater breadth and depth of research on identity of science teachers as whole people. In this study I used a qualitative approach with an emphasis on participant narratives. Through interviews, written reflections, and classroom observations, I re-present the stories of how two middle-school science educators’ identities influence their classroom instruction. Both teachers utilize three-dimensional instruction, but their identities manifest primarily in the ways in which they build classroom communities of practice and support the needs of students
Minutes of a Regular Meeting, The University of Oklahoma Board of Regents, January 12, 2024
No full textSeems fair to me…. An Analysis of Social Equity in Disaster Recovery via Public Perception, Representation, and Practitioner Comprehension
No full textSocial equity has often been the center of academic debate due to a common misunderstanding of fairness and an acceptable definition. Although the discussions are beneficial in developing clarity for scholars regarding social equity in public administration, this research assumes that the need to understand equity can lie within the public’s perception. In the debate over equity, the democratic process is an afterthought but can be a viable addition to the conversation about social equity. As scholars work to develop the idea of equity, the people will have the final say in what equity will be when administered- either by participation or preferred representation. In this research, I utilize disaster recovery literature to administer experiments through surveys to understand how people view social equity and what factors will influence true equity to become an acceptable choice. In addition, I will research what public administrators think about equity and the issues they identify that hinder their ability to implement equity within their community. Overall, the findings reveal more information or options provide people with a higher acceptance of equity. However, the public prefers an equal distribution. Also, the public’s willingness to pay for equity reveals slight leadership preferences when considering trust and program implementation
Creating Occult Identities and Subjects, or, How New NACO and SACO Funnels will Improve Access to Occult Resources
No full textLibrary of Congress Subject Headings (LCSH) and authorities for names, covens, groups, organizations, and especially practitioners of New Religious Movements are lacking. Many of the existing LCSH terms omit scope notes, opening them up to being misassigned to cataloging records. In addition, many practitioners of these movements may be misassociated with the existing terms or unsatisfied with how their creative works have been labeled. Much of this conundrum lies with a lack of knowledge of the subject, but another issue may stem from prejudice. In early 2024, three people met online to consider addressing this problem with the aim of forming an Occult SACO Funnel and a separate Occult NACO Funnel. Learn about the mission, vision, and immediate plans of this exciting project, including how to get involved
Investigating the Leptinergic Regulation of Weakly Electric Fish Communication Signals
No full textAnimals expend energy to gain information from their environments and communicate information to conspecifics. Understanding these energy-information tradeoffs is critical for understanding the constraints that shape animal sensory and communication systems. My dissertation focuses on understanding how animals manage the metabolic costs of active sensory and communication signals. Specifically, we study how the hormone leptin regulates energy-information tradeoffs in animals. These tradeoffs are pronounced in weakly electric fish (WEF) that generate and detect weak electric fields called electric organ discharges (EODs) to sense their environments and communicate. The EODs are produced by the thousands of electrogenic cells (electrocytes) in the electric organ in their tail.
The combination of continuous high-frequency signals to enhance sensory sampling in fast-changing environments and large currents in the WEF’s electrocytes creates significant metabolic costs directly tied to EOD amplitude (EODa). Thus, management of the energy consumption for these sensory signals through behavioral and physiological adaptations is critical for the survival and reproductive fitness of these fish, especially when their aquatic habitats are impacted by anthropogenic changes that disturb their food availability—it then becomes critical to explore anthropogenic implications on the WEF population.
These fish respond to energy shortfalls during food restriction by reducing EODa to conserve energy, but at the cost of degrading sensory and communication performance. EODa recovers to normal levels when fish return to normal feeding. These changes in EODa are mediated by the hormone leptin, a protein hormone that typically plays multiple roles in energy balance, through unknown mechanisms. The primary goal of my dissertation is to investigate the mechanisms through which leptin regulates electrical signal amplitude in WEF.
My dissertation research consists of three chapters that analyzed the role of leptin in regulating animal communication signals, then compared the effects of leptin in two species of weakly electric fish that respond differently to energy shortfalls: Eigenmannia virescens and Brachyhypopomus gauderio. These research projects addressed three related questions: i) How will selective environmental pressures favor leptinergic regulation of communication signaling among different taxa? ii) What are the cellular mechanisms that leptin targets to regulate EODa? iii) How does leptinergic regulation of EODa vary across WEF species with different life histories and reproductive strategies?
Chapter 1– Assessing the importance of leptinergic regulation of vertebrate communication signals.
Animal communication signals are regulated by multiple hormonal axes that ensure appropriate signal targeting, timing, and information content. Although the regulatory roles of many peptide hormones are well understood and documented across a wide range of vertebrate taxa, the role of leptin in regulating animal communication signals remains largely unexplored. Only two recent studies have reported a novel function for leptin in regulating communication signals of weakly electric fish and singing mice. With only limited evidence available to date, in the first chapter of my dissertation, we assessed how widespread leptinergic regulation of communication signals is within and across taxa, and what features of communication signals are subject to leptinergic regulation.
In this paper, we proposed that direct costs arise from metabolic investment in signal production, while indirect costs arise from the predation and social conflict consequences of the signal’s information content. Thus, we proposed a schematic framework for a number of directly testable predictions within and across taxa. Experimental tests of these predictions will lead to a better understanding of when and how selective pressures will favor leptinergic regulation of communication signaling effort and/or signal information content.
Chapter 2 – Investigating the mechanisms through which leptin regulates electric signal amplitude regulation in E. virescens.
I used integrative approaches to determine the cellular and molecular mechanisms associated with leptin-induced regulation of signal amplitude. This chapter describes several different projects directed to answering how leptin regulates the EOD amplitude in E. virescens.
First, we conducted assays to clone and sequence genes encoding the E. virescens leptin receptor (LepR) from the E. virescens’ electrocyte. Then we localized expression of leptin receptors on E. viresens’ electrocyte membranes to understand what the potential cellular targets of leptin are, such as ion channels or receptors that work downstream of leptin receptor to regulate EOD amplitude in E. virescens. The results of LepR localization showed that LepR is co-localized with the electrocyte’s voltage-gated sodium channels and the acetylcholine receptors on the posterior side of electrocyte membrane. Therefore, LepR may regulate the function of voltage gated sodium channel or/and acetylcholine receptors to regulate EOD amplitude in E. virescens.
We evaluated these possibilities with computational analyses to determine whether leptin-induced increases in EOD amplitude are caused by changes in the magnitude of the electrocyte sodium current and\or its cholinergic synaptic current. We performed a parallel analysis to analyze the contributions of electrocyte sodium current and cholinergic synaptic current to increased EOD amplitude in response to the melanocortin hormone ACTH.
These analyses provided a better understanding regarding leptin’s effects on EOD amplitude and whether it uses the same pathway as ACTH in making relative change in the contributions of the synaptic current and the sodium current to EOD amplitude when EOD amplitude changes in response to food deprivation, leptin injections, or ACTH injection.
Chapter 3 – Assessing the peripheral effects of leptin on electric signal characteristics in B. gauderio.
This chapter used a comparative approach to determine whether peripheral leptinergic regulation of electric signal amplitude varies across species with different life histories and reproductive strategies.
Eigenmannia virescens belongs to the Gymnotiform order of South American weakly electric fish that includes more than 200 species with a broad range of electric signal characteristics, ecologies, and life histories. Brachyhypopomus gauderio is another gymnotiform species with different life history and reproductive strategy than E. virescens. Contrary to E. virescens, B. gauderio continues reproductive behaviors even when energy reserves are depleted, and engages in terminal investments in reproduction during stressful periods. Previous findings from these two species of WEF showed that in contrast to E. virescens, food deprivation produces large transient increases in EODa during social challenges in male B. gauderio.
The situationally dependent increase in EODa under food restriction in B. gauderio suggests that different life history and reproductive strategies may drive leptin’s regulatory effect on EODa in opposite directions under different circumstances in E. virescens vs. B. gauderio. However, the effect of leptin on EOD characteristics in B. gauderio has not yet been investigated. For the third chapter of my dissertation, we assessed the peripheral effects of leptin on B. gauderio’s EOD characteristics using similar experimental approaches as Sinnett and Markham (2015) used in E. virescens, aiming to understand whether leptinergic regulation of EODa varies across species with different life histories and reproductive strategies. This study gives us a better understanding of leptin’s full effects on regulating communication signal costs.
Overall, this Ph.D. dissertation contributes to the field of animal behavior by providing critical resources to facilitate comparative studies on mechanisms that balance energy-information tradeoffs in active sensory systems
Evolution of Observed Cloud Organization within Tropical Rainfall Events during the DYNAMO/AMIE Field Campaign
Get PDFTropical convective organization is important for the modulation of the climate on a range of spatial-temporal scales, however the physical processes controlling organization in the atmosphere are still not fully understood. The transient nature of observed convective organization presents challenges to being accurately replicated in models, and a limited number of available observations further challenge our understanding of their driving processes. Cloud organization indices allow us to capture the evolution of cloud organization processes, however results are often sensitive to the choice in existing index used. This project aims to use cloud organization metrics to better understand how convection organizes within rainfall events observed from S-PolKa radar during the DYNAMO/AMIE field campaign. Results show that convection is most organized after peak rainfall. However, the exact timing of greatest cloud organization depends highly on the choice of indices applied. This suggests organization does not lead to increased rainfall, but rather other factors are responsible for upscale growth of tropical convection. It is also found that convective organization of rainfall events depends on the intensity of rainfall, following a sequential process from development to peak rainfall and finally decay