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Border-Lines, Volume XV
No full textBorder-Lines is an interdisciplinary and intersectional academic journal dedicated to the dissemination of research on Chicana/o-Latina/o cultural, political and social issues. Border-Lines is a refereed journal that seeks to publish scholarly articles drawn from a variety of disciplines such as anthropology, education, geography, human health, literary and cultural studies, political science, social work and sociology.This volume showcases works by authors with a focus on emerging Hispanic-Serving Institutions (HSIs) to address celebrations and opportunities along the journey of attaining an HSI designation by the U. S. Department of Education. Border-Lines, Volume XV aligns with the University of Nevada, Reno's vision of becoming an HSI
Towards Safety-Assured Environments of Autonomous Robots via Intent Expressive Autonomy
No full textThis work focuses on improving the safety of human-robot coexistence via intent expressive autonomy. Intent expression between robots and humans is crucial for developing autonomous robots and will enhance human safety. Our research investigated intent expressive autonomy with autonomous-vehicle-to-pedestrian and autonomous-vehicle-to-bicyclist feedback displays. We studied several possible options for an external vehicle display for effective nonverbal communication between an autonomous vehicle and vulnerable road users to identify a feedback module, which increases most legibility, public acceptance and trust in the autonomous vehicle's decision. The initial on-screen study focused on autonomous-vehicle-to-pedestrian communication and was extended by investigating feedback modules for vehicle-to-bicyclist communication. We validated the results from the on-screen studies with immersive Virtual Reality studies, which incorporated real-world setups to replicate pedestrian and bicyclist experiences in traffic. The results overall show that symbols should be selected over text, light, or road projection interaction modes. Further, we investigated intent-expressive autonomy with legible motion in human-robot collaboration to enhance human safety, particularly in cluttered environments. While previous research has focused on uncluttered settings, our work introduces a measure for clutteredness based on an entropic measure of the environment, and a novel motion planner based on potential fields. Tested in a cluttered environment simulating a tool-sorting task, our approach significantly improves legible robot motion compared to the current state-of-the-art legible planner and emphasizes the need to address legible motion in cluttered environments. Additionally, we conducted a human-human study to identify key factors in expressing intent. Through the study we showed that the primary factors which people considered are: timing, direction, avoidance behavior, consistency, angles, position, speed, upper body movement, hand gestures, object proximity, and training effect. We found that legibility correlates with perceived safety, social intelligence, collaboration quality, and trust, underscoring the importance of legible motion. In conclusion, this research demonstrates the critical role of intent-expressive autonomy in enhancing human-robot interaction safety. By focusing on nonverbal communication between autonomous vehicles and vulnerable road users as well as legible motion in cluttered environments, we present important insights for developing autonomous systems that are both intuitive and safe for humans
BUS 101: Introduction to Business Library Lesson Plan
No full textLesson plan for library instruction in BUS 101
Incorporation of Reclaimed Asphalt Pavement (RAP) in P-401 Mixtures
No full textThe use of Reclaimed Asphalt Pavement (RAP) has been widespread in highway pavements for decades, with both laboratory studies and field data demonstrating that RAP in moderate contents, about 20%, can yield mixtures that perform equally or better than virgin asphalt mixtures. As such, the use of RAP has been broadly adopted by various state Department of Transportation (DOTs) across the country. In addition, the use of RAP offers economic and environmental benefits, including lower costs and reduced demand for virgin materials, as well as enhanced sustainability. However, the Federal Aviation Authority (FAA) prohibits the use of RAP in surface course mixtures, as per its P-401 specifications, due to concerns about durability, foreign object debris (FOD) generation, and workability issues. This study examines the feasibility of incorporating 20% RAP into FAA P-401 surface mixtures, utilizing various performance tests to ensure compliance with performance requirements, including durability and workability. The research addresses one of the main challenges with the use of RAP: the recycled binder availability (RBA), which is critical to understanding the effective contribution of aged RAP binder in asphalt mixtures. The traditional methods for volumetric mix design overestimate this contribution, which leads to stiffened mixtures. For mix design, a 1% air void regression approach was applied to mixtures with RAP to offset the deficiency in available binder and improve performance. Laboratory tests indicated that mixes designed in this manner consistently met or exceeded the P-401 specification performance criteria.
The laboratory testing indicated that the inclusion of RAP in airfield surface mixtures, combined with a 1% air void regression that led to the addition of asphalt binder, maintained acceptable rutting resistance while also enhancing the cracking performance. Further, the mixtures performed well in terms of moisture susceptibility and durability. The workability of the mixtures was found to remain within acceptable limits and was highly dependent on the mixture. Overall, the 1% regression in air voids effectively balanced the performance without compromising any key properties, although the results were mixture dependent. These findings support the controlled use of RAP in surface mixtures for airfield pavements; however, this study highlights the need for further evaluation through additional testing and long-term performance predictions
Towards a New Generation of UHPC Spent Nuclear Fuel Storage Systems
No full textSpent nuclear fuel (SNF) is currently stored in a growing number of dry cask storage systems (DCSSs) across the U.S. As policymakers have not yet reached consensus on defined strategies for permanent fuel disposal, the DCSSs will likely be used significantly longer than initially anticipated. The desired extended service life raises concerns about the long-term performance and potential degradation of the commonly utilized concrete shielding structures, which mandates the rethinking of current and future designs with a focus on enhanced durability and longevity. This potential can be realized through the incorporation of advanced materials like ultra-high performance concrete (UHPC), which possesses superior mechanical and durability properties, and is currently making major strides across the globe to use for critical structural applications. However, despite its potential, limited research exists on utilizing UHPC specifically for SNF storage. This doctoral study aims to bridge this gap by comprehensively exploring the viability of a new generation of DCSSs using UHPC with focus on canister-based horizontal storage modules (HSM) that heavily incorporate concrete and susceptible to aging and durability issues. The research methodology integrates a critical review with a suite of advanced numerical simulations. Initially, the dedicated review study identifies concrete degradation mechanisms in DCSSs, and assesses UHPC’s projected performance against these compared to normal strength concrete (NSC). A summary of emerging data on UHPC’s radiation attenuation properties, suggested mix modification, and key knowledge gaps in this domain are provided. Following this foundational review, advanced numerical modeling of an archetype HSM is performed. First, coupled steady-state computational fluid dynamics (CFD) and linear finite element (FE) analyses are used to compare thermal and structural performance of NSC and UHPC under normal operating conditions, evaluating temperature distributions and demand-to-capacity ratios under combined thermal and mechanical loads. Subsequently, transient CFD and nonlinear FE analyses, incorporating a coupled damage-plasticity microplane model and steel reinforcement for NSC and UHPC, are performed to study severe accident thermal conditions (i.e., 40-hour vent blockage), assessing thermal response, structural damage evolution, and the influence of temperature-dependent material properties. Finally, triaxial time-history FE seismic analysis investigates the seismic behavior, examining the effect of global HSM stiffness, using both baseline and thermally degraded properties of NSC and UHPC, on the global and local dynamic responses, including canister and fuel assemblies.
This doctoral research provides compelling evidence that demonstrates the enhanced performance capabilities of UHPC for HSM in DCSSs compared to NSC. The numerical analyses consistently reveal UHPC’s significant advantages in thermal performance under both normal and accident conditions. Furthermore, UHPC exhibits substantially improved structural performance with no damage against severe thermal loads, indicating greater structural robustness for long-term storage. The study also confirms the comparable seismic performance UHPC-based systems while advancing the understanding of the overall seismic behavior of HSMs; an aspect of the behavior that is also needed to assess the what-become long-term storage risks
Multifaceted Role of Sympathetic Influence in the Heart
No full textThe autonomic nervous system continuously modulates cardiac output by balancing sympathetic and parasympathetic input to the heart. The parasympathetic nervous system (PNS) promotes cardiac slowing and stabilizes electrical activity, primarily through vagal input to the myocardium and conduction system. Generally acting in opposition to parasympathetic input, the sympathetic nervous system (SNS) orchestrates critical adaptations in cardiac function under physiological and pathological conditions. This dissertation investigates multiple facets of sympathetic modulation in ventricular myocytes, emphasizing the intricate and receptor-specific mechanisms through which neurohormonal signaling alters ion channel activity and myocardial excitability. First, we examine crosstalk between α1A-adrenergic receptors (α1AARs) and β-adrenergic signaling pathways in adult rat ventricular myocytes. Using FRET-based biosensors, we identify a novel “inside-out” signaling cascade originating from nuclear α1AARs that suppresses β-adrenergic receptor (βAR)-driven cyclic adenosine monophosphate (cAMP) production via a mitogen-activated protein kinase (MAPK) and G protein-coupled receptor kinase (GRK)/arrestin-dependent mechanism. These findings highlight a non-canonical mode of α1AAR function that blunts β-adrenergic signaling and may contribute to the cardioprotective effects observed with α1AAR activation in heart failure. Second, we demonstrate that neuropeptide Y (NPY), a sympathetic co-transmitter elevated after myocardial infarction (MI), exerts dual and receptor-specific modulation of the L-type calcium current (ICaL) in porcine ventricular myocytes. NPY alone enhances ICaL via Y1 receptor-mediated Gq signaling, whereas in the presence of norepinephrine (NE), it suppresses ICaL through Y2 receptor activation of Gi signaling. These effects become regionally dissociated following MI, with Y1-mediated potentiation lost altogether and Y2-mediated suppression persisting only in the infarct border zone, revealing a spatially restricted shift in autonomic signaling within the failing heart. Lastly, we explore the contribution of membrane environment to proarrhythmic drug interactions with hERG (KV11.1) channels. Depletion of membrane cholesterol via methyl-β-cyclodextrin (MβCD) differentially modulates the sensitivity of hERG current to pharmacological inhibitors, enhancing inhibition by ibutilide while attenuating effects of dofetilide and amiodarone. These results underscore the importance of lipid–channel interactions in modulating arrhythmogenic potential of ion channel blockers. Collectively, this work provides novel insight into sympathetic regulation of ventricular electrophysiology, elucidating both receptor-specific signaling pathways and biophysical determinants of channel function. By addressing cross-receptor interactions, regional heterogeneity, and membrane dynamics, these findings refine our understanding of autonomic influence on cardiac excitability in health and disease
Synaptic BRP Alterations in Drosophila Neurodegenerative Models
No full textNeurodegenerative diseases such as Parkinson's and Huntington's disease cause progressive neuronal loss, with early defects at the synapse. Using Drosophila melanogaster, this project examines how disease mutations alter synaptic and protein organization at the neuromuscular junction (NMJ). Previous screening showed changes in NMJ morphology and reduced levels of the protein Bruchpilot (BRP) in Huntington's disease models. Ref(2)P, the Drosophila homolog of the autophagy adaptor p62, forms puncta at protein aggregates to help target them to lysosomes and has been shown to regulate synaptic BRP expression. Because HTT aggregates may influence Ref(2)P, we investigate whether HTT-polyQ promotes changes in Ref(2)P puncta. By analyzing BRP and Ref(2)P across polyQ lengths, this study explores whether HTT-polyQ affects synapse development through a Ref(2)P-dependent pathway
Flies, Data, Robots: Insect-Inspired Flight Strategies for Robust UAV Navigation in GPS Denied Environments
No full textUnmanned aerial vehicles (UAVs) are increasingly called upon to inspect pipelines, track agricultural volatiles, and map disaster zones where Global Positioning System (GPS) signals are unreliable or actively jammed. Inspired by the active sensing strategies of flying insects, this dissertation explores how carefully choreographed flight trajectories can reconstruct lost odometry. I focus on a midsize UAV; however, the results extend to micro UAVs whose size or damage precludes stereo or depth cameras and limits the payload to an inertial measurement unit (IMU), a monocular camera, and a wind probe. Using nonlinear observability analysis, I first show how insects could estimate ground speed and wind speed with their antennae and deliberate maneuvers. Adapting these insights to my UAV, the “BIG BUG,” I designed insect-inspired trajectories such as cross-wind casting (sinusoidal paths), flew them in a motion-capture arena, and fused optic-flow, IMU, and wind sensor data in an estimator. The results demonstrate that these bio-inspired maneuvers improve velocity and wind-state estimates compared with naïve straight-line flight
Summary of Virtual Site Visit with the Oklahoma Department of Transportation (Memorandum C)
No full textThis effort aimed to conduct a comprehensive gap analysis on the use of high-polymer (HP) binders and mixtures, identifying critical limitations, gaps, and needs through a Strengths-Weaknesses-Opportunities-Threats (SWOT) framework. In addition to addressing these gaps, the scope included documenting effective practices and lessons learned by state Departments of Transportation (DOTs). The findings provided DOTs with valuable guidance for designing, constructing, and accepting HP binders and mixtures, complementing work completed under the FHWA EDC-6: Targeted Overlay Pavement Solutions (TOPS) program. To achieve this objective, information was gathered through virtual site visits and other outreach methods with five key agencies, including a session graciously hosted by the Oklahoma Department of Transportation (ODOT).Federal Highway AdministrationUnited States Department of Transportatio
A Computational Investigation into the Strict Core of the 4-player Restricted Houseswapping Game
No full textThis thesis investigates the strict core in Restricted Houseswapping Games with Ordinal Preferences (RHGOPs), introduced by Quint [18]. RHGOPs generalize classical matching models with ordinal preferences, such as the houseswapping game of Shapley and Scarf [24] and the marriage game of Gale and Shapley [9], by incorporating a restricted trading structure. While prior work shows that many restricted houseswapping games have non-empty strict core if strongly balanced, and many RHGOPs in the literature have a non-empty strict core if there are strict preferences, no analogous guarantee exists for the strict core for RHGOPs in general. We conjecture that every RHGOP with strict preferences and a strongly balanced trading structure has a non-empty strict core across all preference structures. We test this with an exhaustive computational analysis of all 220 possible trading structures in 4−player RHGOPs, identify the 167,077 strongly balanced trading structures via Birkhoff-von Neumann decomposition of select doubly stochastic matrices, and confirm that each has a non-empty strict core across all preferences. This supports the conjecture and reveals a new, smallest class of doubly stochastic matrices forwhich the Birkhoff algorithm fails to find all decompositions