https://etd.auburn.edu/handle/10415/1 Mon, 24 Aug 2026 06:35:27 GMT 2026-08-24T06:35:27Z https://etd.auburn.edu/handle/10415/10650 Prenatal Cannabinoid Exposure: Persistent Sex-Dependent Alterations in Hippocampal Inhibitory Signaling and Neurobehavioral Function Wiley, Miles Prenatal cannabinoid exposure (PCE) has increased despite concerns that it may produce lasting effects on brain development and behavior. Delta-9-tetrahydrocannabinol (THC), the primary psychoactive substance of cannabis, crosses the placental barrier and activates cannabinoid receptor type 1 (CB₁R), a key regulator of endocannabinoid signaling during neurodevelopment. Because the endocannabinoid system contributes to the maturation of hippocampal circuits that support learning and memory, PCE may disrupt hippocampal function; however, the underlying mechanisms remain unclear. This dissertation used two prenatal THC exposure models to characterize the developmental, behavioral, molecular, anatomical, and physiological consequences of PCE. In a translational vapor inhalation model, toxicokinetic analyses confirmed systemic THC exposure and neonatal transfer. PCE altered maternal and offspring developmental measures and produced sex-dependent behavioral abnormalities during adolescence, including increased anxiety-like behavior and marginal impairment of recognition memory. These effects were accompanied by sex-dependent changes in hippocampal GABAergic-associated protein expression and CB₁R-associated inhibitory circuitry. A second study used a subcutaneous THC exposure model to determine whether these molecular and anatomical alterations were associated with persistent changes in hippocampal physiology. Following confirmation of THC formulation stability, developmental outcomes, synaptosomal protein expression, and extracellular field recordings were evaluated. PCE increased vesicular glutamate transporter 1 expression in both sexes and produced sex-specific alterations in proteins associated with inhibitory signaling. PCE did not alter basal excitatory synaptic transmission in the absence of gabazine (GBZ), a competitive gamma-aminobutyric acid type A receptor (GABAAR) antagonist. However, partial GABAAR blockade revealed sex-dependent alterations in presynaptic recruitment and short-term plasticity. PCE also reduced long-term potentiation maintenance in both sexes and enhanced long-term depression in males. GBZ modified synaptic depression but did not attenuate the long-term potentiation deficit in THC-exposed offspring. Together, these findings demonstrate that PCE produces persistent, sex-dependent developmental, behavioral, molecular, anatomical, and physiological alterations that extend into adolescence. Across two exposure paradigms, PCE altered hippocampal excitatory and inhibitory signaling, as well as GABAergic regulation of glutamatergic transmission. These findings indicate that PCE-induced hippocampal dysfunction is not explained solely by excessive inhibitory transmission but instead involves disrupted coordination between glutamatergic and GABAergic signaling and impaired synaptic plasticity. Fri, 21 Aug 2026 00:00:00 GMT https://etd.auburn.edu/handle/10415/10650 2026-08-21T00:00:00Z https://etd.auburn.edu/handle/10415/10649 Evaluating the Safety Performance of Centerline Rumble Strips in Alabama Villegas, Michelle Catheryn While research regarding the safety performance of centerline rumble strips (CLRS) has been studied nationally, no research has been conducted for Alabama. As such, the goal of this research is to assess the safety performance of CLRS in Alabama by executing the simple before-after and comparison group methodologies. The simple before-after analysis experienced reductions of -17.4%, -40.8%, and -45.1%, for total crashes, correctable, and correctable fatal and injury (FI) crashes, respectively. The comparison group analysis produced CMFs of 0.94, 0.62, and 0.61 for total crashes, correctable, and correctable FI crashes, respectively. Finally, changes in distribution for primary contributing circumstance and manner of crash were assessed for correctable and correctable FI crashes to evaluate CLRS efficacy across a variety of primary contributing circumstances and distribution of manner of crash commonly associated with crossover crashes. This research affirms the safety performance of CLRS and can support widespread implementation in Alabama. Wed, 19 Aug 2026 00:00:00 GMT https://etd.auburn.edu/handle/10415/10649 2026-08-19T00:00:00Z https://etd.auburn.edu/handle/10415/10648 Artificial Intelligence in K-12 Education: An Investigation of Educators’ Stages of Concern, Perception, and Adoption Williams, Glory Generative artificial intelligence is transforming K-12 education, creating new advantages and significant challenges for educators. Guided by the Concerns-Based Adoption Model (CBAM), this quantitative study examined K-12 educators’ stages of concern regarding AI integration in education; differences in concerns by educator characteristics; the relationships among the stages of concern, perceptions of AI benefits and challenges in education, and adoption intentions. Participants included certified educators from a single public school district in the western United States who completed an adapted version of the Stages of Concern Questionnaire (SoCQ), along with additional survey items on demographics, AI tool use, and two open-ended questions. Quantitative data were analyzed using the SoCQ manual (George et al., 2006), descriptive statistics, Pearson correlations, independent-samples t tests, and one-way analyses of variance. Qualitative responses were analyzed using content analysis. Results indicated that most educators remained in the early stages of concern. AI experience showed stronger relationships with stages of concern than traditional demographics. Educators who reported being in the advanced stages of concern also reported increasingly positive perceptions of AI’s instructional benefits, greater willingness to adopt AI tools designed for educators, and more unease as it relates to ethical AI use. The findings suggest that educators’ responses to AI represent an evolving process rather than simple acceptance or resistance to innovation, even though a cross-sectional design methodology was employed. This study provides several AI implementation recommendations for school leaders, as well as several directions for further research. By applying the Concerns-Based Adoption Model to the emerging field of artificial intelligence, this study contributes to the growing body of knowledge on AI implementation in K-12 framework to support educators through a significant technological innovation. Mon, 17 Aug 2026 00:00:00 GMT https://etd.auburn.edu/handle/10415/10648 2026-08-17T00:00:00Z https://etd.auburn.edu/handle/10415/10647 Experimental Evaluation of Shear and Flexure Behavior of Loblolly Pine Cross Laminated Timber Beams DiSalvo, Blake Cross-laminated timber (CLT) is a commonly used mass timber product that utilizes the strength, sustainability, and constructability advantages of timber while reducing many of the limitations associated with traditional timber construction. Recently, CLT has gained traction as a building material for protective structures due to its sustainability, improved resistance under short-duration loading, and ability to be rapidly deployed and assembled. However, design methods for CLT subjected to blast loading and other dynamic load applications are generally lacking. Such methods need robust understanding of the performance of CLT under quasi-static loading as a baseline for characterizing stiffness, strength, failure mechanisms, and post-peak responses that can then be used to quantify dynamic increase factors (DIF). This study experimentally evaluated the shear and flexure behavior of Loblolly Pine CLT beams subjected to quasi-static out-of-plane loading, with the primary objective of advancing and validating analytical methods for predicting the stiffness and expected strength. A total of 65 one-way bending beam tests were executed using a combination of contact-based sensors and Digital Image Correlation (DIC) techniques to capture the response of the CLT beams. The test matrix included varying the ply count, shear span-to-depth ratio, loading configuration, major/minor strength direction, and member width. The measured and calculated mechanical properties included the effective bending stiffness, apparent bending stiffness, effective shear rigidity, flatwise bending capacity, and flatwise rolling shear capacity. These values were compared to the predictions obtained using the shear analogy method as detailed in PRG-320 and PDC-TR 18-02. The study discovered that the ultimate strength predictions were generally conservative, but the degree of conservatism was dependent upon specimen geometry, loading configuration, and failure mode. The shear and flexural failures were highly dependent upon the shear span-to-depth ratio with shorter ratios resulting in shear failures and larger ratios resulting in flexural failures. The stiffness results follow similar trends to previous tests on comparable specimens with the apparent bending stiffness and the effective shear rigidity measuring higher than predicted and the effective bending stiffness measuring lower than predicted. The global response and post-peak behavior of the specimens was highly dependent upon the failure mode. The flexural failures were very brittle with sudden drops in the load carrying capacity of the beams. Conversely, the rolling shear failures developed more progressively and often displayed a gradual “stair-stepping” reduction in the load carrying capacity. Altogether, this study contributes toward a better understanding of the strength, stiffness, failure mechanisms, and residual response of Loblolly Pine CLT beams. Mon, 17 Aug 2026 00:00:00 GMT https://etd.auburn.edu/handle/10415/10647 2026-08-17T00:00:00Z