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Phenotypic variation in neural sensory processing by deletion size, age, and sex in Phelan-McDermid syndrome
Get PDFFinancial support was provided by the University of Oklahoma Libraries' Open Access Fund.Background
Phelan-McDermid Syndrome (PMS) is a rare genetic condition characterized by deletion or mutation of region 22q13.3, which includes the SHANK3 gene. Clinical descriptions of this population include severely impaired or absent expressive language, mildly dysmorphic features, neonatal hypotonia, developmental delays, intellectual impairments, and autistic-like traits including abnormal reactivity to sensory stimuli. Electroencephalography (EEG) has shown promise as a tool for identifying neurophysiological abnormalities in neurodevelopmental disorders. However, few EEG studies focused on sensory processing have been performed on this population. Thus, this study focuses on comparisons of event-related potential (ERP), event-related spectral perturbation (ERSP), and inter-trial coherence (ITC) between PMS and typically developing (TD) individuals in a standard auditory gating task measuring attenuation of neural activity to repetitive auditory stimuli.
Methods
A total of 37 participants, 21 PMS (12 females, age range 8–18.6 years) and 16 TD individuals (8 females, age range 8.2–15.3 years) were included. Analysis consisted of a series of general linear models using a regional (frontal) and global (whole-head) approach to characterize neural activity between PMS and TD participants by age, sex, and group.
Results
Most notably, individuals with PMS had delayed or low amplitude P50, N1, and P2 responses in frontal and whole-head analyses as well as poor frontal phase-locking to auditory stimuli for alpha, beta and gamma ITC, indicating impaired processing of stimulus properties. Additionally, individuals with PMS differed from TD by age in delta, theta, and alpha power, as well as frontal beta-gamma ITC, suggesting different developmental trajectories for individuals with PMS. Within PMS, larger deletion sizes were associated with increased auditory processing abnormalities for frontal P50 as well as whole-head P50 and N1.
Limitations
This is one of the largest EEG studies of PMS. However, PMS is a rare genetic condition, and our small sample has limited statistical power for subgroup comparisons. Findings should be considered exploratory.
Conclusions
Results suggest that participants with PMS exhibit auditory processing abnormalities with complex variation by deletion-size, age, and sex with congruency to impaired early recognition (P50), feature processing (N1), information integration (delta, theta), sensory processing and auditory inhibition (alpha), and inhibitory modulation of repeated auditory stimuli (beta, gamma). Findings may provide valuable insight into clinical characterization of sensory and speech behaviors in future studies.Ye
GEOPHYSICAL INVESTIGATION OF IRON-SULFUR REDOX DYNAMICS IN SULFIDIC SOILS: A CASE STUDY FROM ZODLETONE SPRING, OKLAHOMA
Get PDFThis study investigates subsurface iron-sulfur redox dynamics in anaerobic acidic sulfate soils at Zodletone Spring in southwest Oklahoma by integrating noninvasive geophysical method electromagnetic induction (EMI) and Indicator of Reduction In Soil (IRIS) devices. EMI was used to collect apparent electrical conductivity (ECa), which was processed through inversion modeling to better estimate true electrical conductivity (EC) and generate a three-dimensional model of the subsurface. Slices of the model revealed distinct redox transitions between 0.4-0.6m across majority of the study area. IRIS devices confirmed strongly reducing conditions through the removal of iron oxide paint (FeOOH) and precipitation of iron monosulfides (FeS). A statistically positive correlation was observed between elevated EC and FeS coverage (R2 = 0.52, p = 0.008), while remaining FeOOH showed a negative correlation with EC (R² = 0.59, p = 0.003), supporting the use of EMI as a noninvasive proxy for monitoring redox activity. These findings demonstrate the value of EMI for identifying redox transition zones in acidic sulfate soils, with important implications for monitoring acidification through oxidation and supporting wetland remediation. The findings also suggest broader relevance for planetary exploration, where subsurface iron-sulfur cycling in low oxygen environments may serve as a biosignature of microbial habitability
ISANDI SOLWIMI LWESIXHOSA: A VOCAL WESTERN CLASSICAL APPROACH TO XHOSA LANGUAGE AND ITS UNIQUE CLICK SOUNDS
No full textABSTRACTThe document examines the incorporation of Xhosa click consonants into Western classical vocal techniques and compositions, focusing on works by South African composer Nqobile Nkonzo. This study explores the preservation of indigenous languages and the expansion of vocal classical music boundaries, highlighting the potential for cultural enrichment and artistic innovation. It investigates the integration of Xhosa's three primary click types - dental (c), alveolar lateral (x), and alveolar (q) - in Western classical music, using a mixed-methods approach combining acoustic analysis, linguistic examination, and cultural interpretation. Spectrographic software analyzes click properties in both linguistic and musical contexts, while phonetic transcription explores click distribution within musical frameworks. By comparing click usage in Western art music, Xhosa traditional music, and everyday speech patterns, the study evaluates how this incorporation contributes to linguistic preservation and cultural promotion. The research aims to bridge ethnomusicology, linguistics, and classical music studies, offering new perspectives on notating and teaching Xhosa clicks in Western classical contexts. This interdisciplinary approach fills a significant gap in current research, ultimately contributing to the diversification of classical music repertoire and fostering cross-cultural understanding in an increasingly globalized world. Each chapter contains information that plays a vital role in the creation and development of this research project, especially female Xhosa singers like Miriam Makeba, who introduced the Xhosa click consonants to internationally diverse audiences
VHF Power Delivery Through Tunable Impedance Matching
No full textElectromagnetic-based cancer ablation represents an innovative approach to selectively target and destroy cancerous tissues while minimizing damage to healthy cells. One promising mechanism under investigation involves using electric fields to induce localized heating within the targeted tissue. A key challenge in such systems is the ability to deliver energy in a controlled and localized manner, particularly as the electromagnetic properties of the target material vary with frequency and composition. This thesis investigates a tunable matching network and parallel plate structure designed to enable efficient energy transfer to materials under test. This method allows localized electric fields to be induced within the material, facilitating controlled heating. In an effort to maximize energy transfer to a material under test, a tunable impedance matching network design is a key focus of this work. The impedance matching network is characterized by its ability to dynamically adapt to varying complex impedances and frequency-dependent material properties, such as dielectric permittivity, across a frequency range of 20-100 MHz. Commercially available systems are largely limited to fixed-frequency designs, unable to accommodate changing material impedances or optimize energy transfer, making them unsuitable for applications requiring such adaptability. This work addresses these challenges inherent to systems involving changing material properties. This work addresses these limitations by presenting a tunable, system capable of matching to evolving load conditions, thereby enabling efficient energy transfer in scenarios where existing commercially available systems fall short. Complementing the matching network, a set of parallel plates provides the physical structure through which energy can be delivered to a material under test. The parallel plate design builds on those used in previous work, refining the geometry to better contain the electric field between the plates. This refinement aims to reduce radiative losses and improve the efficiency of energy transfer to the material under test, while maintaining continuity with the earlier system's design principles. These improvements align with the broader objective of increasing the specificity of energy delivery while also enhancing non-radiating behavior. Beyond system design, this work uses electromagnetic simulations to investigate the RF interactions of materials like carbon nanotubes (CNTs), which are of particular interest for their potential role in future heating experiments using evolutions of this system. While CNT-based heating is not the primary focus of this thesis, understanding their behavior under RF exposure supports the long-term goal of applying this system to materials with complex electromagnetic properties. Simulations from an electromagnetics perspective provide insights into the RF-induced behaviors of CNTs observed in literature and relevant research. The observed charge distributions and dipole behavior, previously leveraged in other studies to achieve localized heating, help to further contextualize the mechanisms underlying CNT-based RF heating applications. This understanding bridges gaps in existing research, where experimental outcomes have been documented but the mechanisms driving these behaviors remain underexplored. This work proposes and demonstrates a manually tunable, lumped-element matching network integrated with a refined parallel plate structure for controlled RF energy delivery. The system is validated through both simulation and experimental testing, demonstrating the ability to adapt to varying load conditions and maximize energy delivery across a larger frequency range of 20-100 MHz. This system addresses key limitations observed in fixed-frequency commercially-available designs, contributing a practical step towards scalable systems for targeted radiofrequency (RF) energy delivery and localized heating. Lastly, this work highlights practical design challenges and tradeoffs, offering insights and recommendations to guide future implementations and evolutions of this work
Degrees of Indigenous Autonomy: Aestheticizing Artistic Survivance in Colonial Cuzco (1690s-1780s)
No full textFrequently, Indigenous studies scholars apply theoretical approaches and methodologies to assess Europe's impact on the Americas. In an art historical context, there is a persistent tendency to narrate Indigenous traditions and material culture from the perspective of a Euro-American Western society, placing Indigenous works of art at the bottom of a hierarchy of aesthetics. Contrary to most published research, I aim to draw upon my Indigenous perspective as a person of Peruvian and Shasta heritage to aid my examination in highlighting the inequalities and disparities present within the visual interactions and exchanges of the early modern period. Through the artworks of three biracial Indigenous painters from Cuzco, which include Basilio de Santa Cruz Pumacallao, Marcos Zapata, and Antonio Oblitas, I explore themes of identity, historicity, and coloniality. My research begins with an analysis of these three artists, positioning them as active agents who, despite the constraints of colonialism, used their interracial identities and artistic practices to assert Inca cultural presence. The composition of the thesis is based on a chronological sequence of their paintings created between the late 1690s and the early 1780s. Each artist serves as an individual case study to illuminate their individual and significant contributions to Indigenous resistance. While this structure emphasizes each of their efforts, I also aim to demonstrate a broader pattern of Indigenous opposition and visual defiance over nearly a century. I assert that the colonization of Latin America is evident in these artists’ works, where they employed subversive aesthetic techniques to counter oppressive elements, such as heteropatriarchy, forced assimilation, and Eurocentric modernity. By examining their strategies of resilience and adaptation, I aim to contribute to the growing efforts to decolonize art history. In totality, this study challenges dominant narratives, highlighting the realities of colonization in the Americas and the enduring presence of Indigenous resistance, creativity, and survivance
Real Time Hybrid Simulation Testing of a Rolling Isolation System
No full textSeismic base isolation is a common engineering practice in regions where earthquake activity is frequent. Base isolators can be designed to reduce structural displacement and sustained accelerations, mitigating the effects of an earthquake induced ground acceleration on a structure. Although base isolators are highly effective in reducing the transmission of these accelerations, there exists uncertainty in the dynamic response of base-isolated structural systems under varying frequencies (low- and high-frequency seismic waves). These dynamic response uncertainties can be taken into account with full-scale testing of base isolated structures; however, high costs and lack of resources for full-scale testing limit research in this field. Real-time hybrid simulation (RTHS), which involves numerical modeling of a structure’s dynamic behavior while testing a portion of the structural system, allows researchers to bypass the challenges of full-scaletesting. RTHS allows for an extended scope of testing, cost efficiency, flexibility, adaptability, and enhances the accuracy and precision of numerical modeling techniques in this field. This thesis explores the dynamic response of a superstructure on a ball-n-cone designed rolling isolation systems (RIS). The RIS allows for an increase in displacement capacity while reducing ground acceleration transmission with the use of a rubber rolling element (ball). A RTHS testing framework is developed, in which a state-space numerical model is utilized to model the dynamic behavior of a superstructure while experimentally testing a RIS supporting an idealized mass. A Quanser Shake Table II (STII) was utilized to induce relative displacement across the RIS, while the top of the RIS was help fixed using a brace equipped with a load cell to measure the restoring force. Control and compensation using static-time series compensation (STS) is applied to ensure accurate execution of STII command displacement and to mitigate communication delay during experimental testing at time steps of 0.001 s. Performance of the RTHS testing framework is further validated with a linear elastic structure. The RIS was determined to have high displacement response mitigation for one degree-of-freedom (1DOF) and two degree-of-freedom (2DOF) cases. Impulse loads and band-limited white noise (BLWN) excitations were successfully mitigated. However, high-frequency oscillatory responses (5-8 Hz) were observed at small displacements. These were determined to be an artifact of RTHS, where negative damping within the RTHS testing system is equal to damping within the RIS. This led to zero total damping, resulting in the observed oscillatory displacements after the strong shaking
STUDENT MOTIVATION AND ITS RELATIONSHIP WITH ENGAGEMENT AND ACADEMIC ACHIEVEMENT AMONG FULL TIME VIRTUAL SCHOOL STUDENTS
No full textVirtual school enrollments in the United States have been steadily increasing over the past 25 years. Yet, studies have routinely shown that the academic performance of full-time virtual school students is considerably below that of their brick-and-mortar peers. To understand these results, theoretical reasoning suggests that motivation may be an important factor as students may need to be highly self-motivated to engage with online learning programs effectively. However, very little empirical work has tested the relationship among student motivation, engagement with learning platforms, and outcomes among full-time K-12 virtual school students. The purpose of this study was to examine these relationships by analyzing administrative data and surveys given to 6-12 grade students (n=212) in a full-time virtual school in an urban school district. Results indicated no statistical association between measures of self-reported motivation and engagement with learning platforms. However, self-reported internalized motivation was associated with student outcomes (i.e., course completion and grades). This study contributes to a growing body of literature on full-time virtual school students’ motivation, achievement, and participation in online learning activities
Thinking Beyond Your Own Experience: How Expert Cases and Guidance Enhance Creativity for Non-Experts
No full textResearch suggests that when individuals have limited prior knowledge, drawing from concrete past cases rather than abstract concepts enhances conceptual combination and creativity. However, it remains unclear whether these cases should stem from personal experiences or expert-provided sources. Additionally, there is little guidance on which aspects of personal experiences contribute to higher creative performance, warranting an initial investigation into their role in problem-solving. This two-study effort examined how 347 college students designed a high school curriculum using either personal experiences, expert-provided cases, or a combination of both, with some also receiving heuristic guidance to aid conceptual combination. Results showed that personal experiences associated with positive outcomes and emotions were linked to higher creative performance. However, Study 2 revealed that expert-provided cases combined with heuristic support led to greater conceptual combination effectiveness, improving solution quality and elegance, suggesting that external expert cases may be preferable for individuals with low-to-moderate expertise. Interestingly, more effective case combination was associated with reduced originality, underscoring a potential tradeoff between heavily relying on past cases and novelty. These findings highlight how case source and heuristic guidance shape creative problem-solving, offering insights into optimizing knowledge integration strategies for individuals with limited domain expertise
SCALABLE MULTI-AGENT COLLABORATION FOR RADAR TASKS
No full textWe examine the challenge of multi-agent command and control (C2) scenarioswhere autonomous agents accomplish objectives by observing their environment, deciding optimal actions to meet the objective, and then act upon their environment. The most common method for these agents to observe their environment is through the use of radar. The domain of cognitive radar follows a similar perception-action cycle and accomplishes radar resource management (RRM) tasks. Modern C2 challenges with multiple autonomous agents using radar presents a unique challenge to both domains. Multi-agent autonomy is often formulated without the uncertainty and complexity of higher-fidelity radar and radar task methods often optimize singular systems as opposed to coalitions of agents. The integration of radar task methods with multi-agent systems presents a unique challenge that requires maximization of collaborative utility instead of singular performance. This work examines C2 challenges where agents have increased uncertainty and reduced resources but can and should coordinate actions. We designed a simulation environment for C2 challenges with medium fidelity radar detection simulations. Within this environment, we present agent action methods in the fields of machine learning and reinforcement learning to perform with low resources and increased uncertainty. Novel to this work is the use of game theory and meta-cognition to coordinate multiple agents for increase utility in the radar tasks of detection, track confirmation, and optimal surveillance. In order to meet the needs of the C2 domain, special attention is paid to methods that are scalable and modular
CPAs vs. AI Tax Advisors: Evaluating Reliance Across Advisory Contexts
No full textAdvancements in generative artificial intelligence (AI) have led to the public deployment of AI chatbots that provide tax planning and compliance advice. This monumental development in the tax advisory landscape enables individual taxpayers who prepare their own tax returns to meaningfully conduct their own tax research. In this study, I address two fundamental questions. First, to what extent are taxpayers willing to rely on AI advisors? Reliance on AI is compared to that placed on certified public accountants (CPAs), a known benchmark for tax advice quality. Second, this development increases the importance of understanding taxpayers’ preference for aggressive or conservative advice, particularly for those who prepare their own tax returns. Do self-preparers exhibit a preference for aggressive advice? To investigate these questions, I conduct a randomized experiment that manipulates advisor type and aggression to shed light on how these factors influence taxpayers during the reporting process. Trust and advocacy are examined as mechanisms driving differential reliance on advisors. Results provide evidence that self-preparers are influenced by AI advisors, and are more likely to rely on AI-provided advice when it is aggressive than when it is conservative. However, taxpayers express less reliance on AI compared to CPAs, an effect driven by perceptions of CPAs’ tax expertise and commitment to minimizing tax burden. The study provides insights for the research community, professional tax service providers, legislators, regulators, and other policy makers considering the implications of this rapidly evolving technology