Washington University Medical Center
Washington University St. Louis: Open ScholarshipNot a member yet
26344 research outputs found
Sort by
MEMS 4110: Conservation of Angular Momentum Demo
No full textA demo was built to serve as a hands-on experience for reinforcing concepts behind the conservation of angular momentum
MEMS 4110: Rapid Drink Chiller
No full textThe purpose of this document is to outline the purpose and function of the rapid drink chiller device. This device is designed to replace traditional portable drink cooling methods, such as traditional styrofoam coolers, fridges, etc. Traditional methods require the transport and inclusion of ice, and require overly long cooling times, with the exception traditional fridges which are non-portable. The rapid drink chiller is designed to be light and compact in order to maximize transportability, accomplished via an all foam insulation construction around a waterproof box. The box is filled with a water-ethanol solution which is cooled to extremely low temperatures utilizing an embedded refrigerant system, with a series of rollers on top of the refrigerant cooling lines. Cans are placed on these rollers and semi-submerged in water, with the rollers themselves operated via a hand crank system. This rotates the cans, allowing for convection inside of the can as well as in the liquid outside of the can increasing the rate of heat transfer. This results in significantly decreased cooling times, with the device capable of cooling four 16 ounce cans to 40 degrees Fahrenheit in under 20 minutes, or four standard 12 ounce cans in under five minutes
Explainable Decision-Making: From Formal Logic to AI Systems with Explainable Behavior
Get PDFThis thesis makes the claim that logic-based frameworks can serve as an explainability layer atop AI systems, capable of generating rigorous and flexible explanations for human users across diverse problem domains. We support this claim through a progression of novel theoretical frameworks and practical implementations, starting with a general logic-based framework for generating explanations from the knowledge bases of an AI system and a human user and showing how it can be used on a diverse set of problem domains. We then systematically extend this framework with capabilities crucial for real-world applications: probabilistic reasoning for handling uncertainty, personalization through vocabulary-based abstraction, and dynamic interaction through argumentative dialogues. Building on these foundations, we address additional challenges by developing privacy-aware explanations for multi-agent systems and exploring explanation-guided approaches to belief revision that better align with human cognitive processes. To make our methods more accessible, we demonstrate how it can be effectively combined with large language models to generate natural language explanations while maintaining formal guarantees. Our theoretical contributions are complemented by efficient computational methods that make these frameworks more practical, as demonstrated through extensive evaluations across diverse problem domains. Recognizing that the ultimate test of explanatory frameworks lies in their effectiveness with real human users, we validate our approaches through several human-subject studies that show high comprehension of the explanations as well as high overall satisfaction with the explanation process, thus providing some evidence for the effectiveness of our approaches in enhancing human-AI interaction. By showing how logic can serve as a robust explainability layer that bridges the decision-making processes of AI systems and human understanding, this work aims to contribute to the development of AI systems that are not only powerful but also understandable, trustworthy, and above all, human-aware
Abolish What?
Get PDFFrom leading academic journals to popular press outlets, abolitionist activism and scholarship have earned airtime in national debates about criminal justice reform. But what is abolition? When scholars, lawyers, and activists talk about abolition, they seem to mean very different, even conflicting, things. In this Essay, I focus on a core question that might divide different abolitionists-and different critics of abolition: what is to be abolished? Abolitionists argue that it\u27s critically important to abolish something, while critics of abolition insist that something is necessary to a well-functioning society. Yet, it\u27s not always clear what that something is-both for abolitionists and their critics. Defunding police is different than defunding prisons, and defending police is different than defending prisons. In this Essay, I argue that contemporary debates about abolition would benefit from greater clarity. I lay out a range of different targets for abolitionists-prisons, police, the prison industrial complex, and a number of broader cultural and structural phenomena. In explaining how these different targets might make for different abolitionisms, I raise what I take to be the core theoretical and practical questions for each abolitionist project. I hope to drill down on different understandings of abolition -what might they entail, and what questions do they raise? More precision won\u27t necessarily resolve increasingly common debates about abolition versus reform. Nevertheless, more precision might make those debates more productive. To the extent that academic engagement with abolitionist activism and theory continues to increase, it\u27s worth stepping back to make sure that we aren\u27t talking past one another.
From leading academic journals to popular press outlets, abolitionist activism and scholarship have earned airtime in national debates about criminal justice reform. But what is abolition? When scholars, lawyers, and activists talk about abolition, they seem to mean very different, even conflicting, things. In this Essay, I focus on a core question that might divide different abolitionists-and different critics of abolition: what is to be abolished? Abolitionists argue that it\u27s critically important to abolish something, while critics of abolition insist that something is necessary to a well-functioning society. Yet, it\u27s not always clear what that something is-both for abolitionists and their critics. Defunding police is different than defunding prisons, and defending police is different than defending prisons. In this Essay, I argue that contemporary debates about abolition would benefit from greater clarity. I lay out a range of different targets for abolitionists-prisons, police, the prison industrial complex, and a number of broader cultural and structural phenomena. In explaining how these different targets might make for different abolitionisms, I raise what I take to be the core theoretical and practical questions for each abolitionist project. I hope to drill down on different understandings of abolition -what might they entail, and what questions do they raise? More precision won\u27t necessarily resolve increasingly common debates about abolition versus reform. Nevertheless, more precision might make those debates more productive. To the extent that academic engagement with abolitionist activism and theory continues to increase, it\u27s worth stepping back to make sure that we aren\u27t talking past one another
Crimes Against Humanity and Customary International Law
Get PDFA draft text of a treaty on the prevention and punishment of crimes against humanity was finally sent to negotiations by the U.N. General Assembly on December 4, 2024, after six long years of advocacy by States and civil society. Questions remain, however, with regard to how crimes against humanity will be defined in the new treaty. On the one hand, some States have embraced a definition of crimes against humanity that tracks Article 7 of the Rome Statute of the International Criminal Court (“ICC”). Other States have rejected Article 7 as the basis for the new treaty, but theirs is a minority view. Finally, some have suggested that given the passage of twenty-five years since the ICC Statute was adopted, the definition of crimes against humanity in the new treaty could include new crimes either by way of codification (e.g., the slave trade), crystallization (e.g., forced marriage), or evolution (e.g., environmental crimes and colonial crimes). This Chapter explores the historical emergence and development of crimes against humanity in customary international law and then evaluates State positions regarding the unity, evolution, and diversity of their approach to this important international crime. The Chapter recognizes the value of having a common “minimum standard” by way of definition, in which the Rome Statute provision is the “floor,” so as to avoid fragmentation and enhance the legality principle. At the same time, it recognizes that modest improvements to the text may be desirable, and that retaining flexibility in the definition of the crime is consistent with current state practice and will allow it to evolve and remain a critically important legal protection for civilian populations during armed conflict and in peacetime
Molecular Dynamics and Computational Predictions of T-cell Activation
No full textPredicting T-cell receptor (TCR) specificity is one of the hardest challenges in immunology owing to difficulties in perturbing this system experimentally and computationally. Successful prediction of TCR specificity can offer a powerful to tool to study T-cell tolerance, antigen recognition, and autoimmunity as well as open doors towards de-novo TCR design and TCR-based Chimeric Antigen Receptor (CAR) T therapies. In this work, we developed a computational model based on experimental insights, molecular dynamics simulations (MD), and machine learning (ML) that can reliably predict TCR specificity towards peptide-class II major histocompatibility (pMHCII) complexes. Our model leverages biophysical information from MD simulations of AlphaFold3 generated TCR-pMHCII complexes to reliably predict T-cell activation outcomes. Inclusion of a novel biophysical parameter termed nonconvex interactions combined with interaction energy calculations, allowed us to improve T-cell activation predictions over an ML model only trained on interaction energies and also offer a compelling theory for TCR specificity encoding via kinetic entrapment
Observational Properties of Near-Maximal Spin Black Holes with the EHT
Get PDFIn 2021 and 2024, the Event Horizon Telescope (EHT) collaboration published the first polarized images of the supermassive black holes (SMBHs) M87* and Sgr A*, which allowed us to place important constraints on the accretion flow and underlying space-time. Of particular interest is the dimensionless spin parameter a• , which theoretically may attain a maximum value of a• = 0.998 when spun up by a thin accretion disk. On the other hand, mechanisms including incoherent accretion, SMBH mergers, and spin extraction via jets, are hypothesized to spin down SMBHs from these near-extremal values. In this work, we perform general relativistic magnetohydrodynamics (GRMHD) simulations of a• = 0.998 SMBHs with advection-dominated and strongly magnetized accretion disks to determine their observational characteristics. First, we evolve the fluid in a Kerr space-time to study black hole properties, including variability, magnetic flux accumulated on the horizon, and jet power. Then, we perform general relativistic ray-tracing (GRRT) to produce polarized movies that can be directly compared to current and future EHT observations. We predict increased jet power efficiency as well as distortions to the photon ring which should be an accessible signature that extensions to the EHT, such as the next-generation EHT (ngEHT) and Black Hole Explorer (BHEX), can then use to rule out such models
Enhancing Diversion Success through Financial Capability and Asset Building: A Framework and Proposed Intervention
Get PDFMass incarceration policies in the United States have generated the highest incarceration rate in the world, yet many incarcerated individuals have committed nonviolent offenses or been confined because they could not pay fines or fees. Diversion offers an opportunity for justice-involved individuals to avoid conviction and collateral consequences while maximizing public safety, reducing case processing, decreasing overpopulation in prisons, and lowering costs. However, diversion programs do not adequately address financial instability and insecurity that often contribute to criminal behavior. This paper reviews evidence on adult diversion programs and proposes an intervention approach responding to socioeconomic factors contributing to criminal behavior
Buffalo Bill and the Great Western Story
Get PDFThe author investigates how narratives are constructed through visual culture to better understand her own history. Buffalo Bill’s Wild West Show acts as a case study demonstrating how “history” is often a narrative established by those in power. These narratives often essentialize their subjects, leading to erasure and exclusion. Sitting Bull and Annie Oakley are used as examples of figures that have become caricatures in service to a greater narrative about the American West. This paper argues for the inefficacy of considering any one narrative as “history” instead recommending a close reading of many different narratives. Three different Western figures, all associated with Buffalo Bill’s West Show, are introduced and analyzed. The author argues that much of the nuance of history is lost when we favor only the narratives found in popular culture
Unmeasured, detached, and isolated: The legitimation of a domesticated identity
Get PDFUnmeasured, detached and isolated explores the lingering effects of colonialism on identity, behavior, and cultural perception through the lens of my personal experience as a Venezuelan immigrant in the United States. I investigate how colonial legacies—especially those codified through manuals of etiquette like Manuel Antonio Carreño’s Manual de Urbanidad y Buenas Maneras—continue to shape self-perception and societal expectations. Through video, sculpture, miniatures, and installation, I reconstruct a visual language that resists simplification and reclaims complexity. Engaging with the symbolic weight of tropical imagery, domestic spaces, and hybrid aesthetics, my work challenges Eurocentric frameworks and examines the figure of the migrant as a socially constructed “stranger.” By foregrounding opacity, disorder, and play, the thesis text and artwork open space for alternative ways of knowing and being—seeking not to resolve identity but to hold its contradictions. The project becomes both a critique of inherited norms and a speculative proposal for cultural reimaginin