Digital Commons Network^™

Automatic Chain Cleaner, Daniel Cherenson, Rudy Lawler, Darius Rucker

Mechanical Engineering and Materials Science Independent Study

The Automatic Chain Cleaner (ACC) is a battery-powered tool that clamps onto a bicycle frame and encloses the chain while cleaning it with brushes and degreaser and/or water. The batteries power a motor that drives the chain in the reverse direction from normal bicycle use. Clamps stabilize the tool and provide a consistent and stable cleaning job. This project aims to replace the manual versions of thistool which suffer from lack of stability and a poor user experience. Ease of use and reliability are important requirements for this project. The ACC will take 4 AA batteries and will run smoothly …

Validating An Open-Source Uvlm Solver For Analyzing Flapping Wing Flight, Cameron Urban

Mechanical Engineering and Materials Science Independent Study

Scientists have long used the unsteady vortex lattice method (UVLM) to simulate flapping wing flight. However, until recently, there has not been an available open-source UVLM solver designed explicitly for this field. Ptera Software is the only open-source UVLM solver that can simulate flapping wing aerodynamics without the modifications required by other open-source solvers. This report documents the next step in the software’s development: validation of its results. Comparing Ptera Software’s output to high-fidelity experimental data of the pressures on a flapping wing robot shows that the simulated results predict the trends and magnitudes of the net lift over time …

Social Determinants Of Health: The Impact On Health Outcomes And Hospital Profitability, Danielle Mcpherson

Doctor of Business Administration Dissertations

Hospitals are experiencing decreasing profitability due to increasing healthcare cost. In this paper, I demonstrate that there is financial value to hospitals by addressing social determinants of health (SDOH) as this strategy improves health outcomes and yields cost savings. I estimate the impact of SDOH on the health outcomes using an IV probit regression analysis and estimated the impact of health outcomes on cost using a basic linear regression. I estimate that improving SDOH by one standard deviation will result in hospital cost savings as follows: addressing Violent Crime will decrease hospital cost between 0.16% and 0.21%, addressing Supplemental Nutrition …

Advances In The Understanding Of Auxin Signaling Through Indirect Mechanisms, Ryan Joseph Emenecker

Arts & Sciences Electronic Theses and Dissertations

The plant hormone auxin is remarkable in its capacity to seemingly regulate all plant growth and developmental processes. Because of this, plants have evolved numerous mechanisms to allow for specific responses to auxin dependent on tissue type and developmental stage. Despite the importance of this specificity, we understand very little with respect to the molecular mechanisms underlying it. In this work, we examine two mechanisms used by plants to modulate auxin response across different tissues. First, we describe our finding that auxin interactions with another plant hormone, abscisic acid, is used as a mechanism to regulate auxin responsiveness in the …

Synthesis Of Linear Oligo[N]Catenanes Via Orthogonal Metal Templation, Nathan Colley

Arts & Sciences Electronic Theses and Dissertations

No abstract provided.

Structural Insights Into Host-Pathogen Interactions Of Alphaviruses, Katherine Basore

Arts & Sciences Electronic Theses and Dissertations

Alphaviruses are arthropod-borne, single-stranded positive-sense RNA viruses of the Togaviridae family that infect various vertebrates worldwide in tropical and temperate areas, causing emerging and reemerging diseases in humans. Mature virions are 70 nm in diameter and contain a ~11-kilobase genome encapsidated within a nucleocapsid core, a host-derived lipid bilayer, and an envelope comprised of heterodimers of the glycoproteins E1 and E2 arranged into trimeric spikes with T=4 icosahedral symmetry. Alphaviruses are categorized into two groups based on their clinical symptoms: the arthritogenic alphaviruses, such as chikungunya (CHIKV), Mayaro (MAYV), Ross River (RRV), Semliki Forest (SFV), and O’nyong-nyong (ONNV) viruses, which …

The Decision Maker: Understanding The Role Of Ifrd1 In Urothelial Plasticity And Regeneration, Bisiayo Erionmwon Fashemi

Arts & Sciences Electronic Theses and Dissertations

The bladder urothelium forms a highly specialized watertight barrier to urinary wastes. The urothelium offers an unusual example of tissue regeneration: although urothelial cells do not rapidly turn over under physiological conditions, they have an impressive capacity to regenerate tissue upon injury. Even more remarkable, depending on the modality of injury (sterile, infectious) there appear to be two distinctive modes of urothelial regeneration. We have previously shown that in response to a urinary tract infection (UTI), the urothelial stem cell niche becomes activated and induces rapid restoration of the urothelium, whereas, regeneration following sterile injury does not involve stem cell …

Induced Flow In Coaxial Rotor Systems, Andrew Bergantz

Mechanical Engineering and Materials Science Independent Study

In coaxial rotor helicopter systems, both rotors of the helicopter spin in opposite directions on the same vertical axis, requiring the bottom rotor to spin faster with a higher blade pitch angle and the top rotor to spin slower with a lower blade pitch angle. This was proven by Peters and Seidel [1]. As both blades are spinning, there is an induced flow of air between the rotors. The solution of the potential flow equations shows that the flow induced by the upper rotor on the lower is related to the adjoint velocity above the rotors and the time delays …

Covid-19 Educational Inequities: Shining A Light On Disparities In A Graduate School Of Social Work, Jason Jabbari, Dan Ferris, Tyler Frank, Michal Grinstein-Weiss

Social Policy Institute Research

In the wake of COVID-19, universities and schools of social work face unprecedented challenges and uncertainty in aligning their academic models with public heath protocols and best practices, while prioritizing the safety and well-being of their students. In order to best respond to these challenges and uncertainty, more research is needed to advance a greater understanding of (1) what challenges students face, (2) who is most at risk and impacted by these challenges, and (3) how universities can best support students. Through a survey administered during the spring 2020 semester at a large research university in the Midwest, we explored …

Racial And Ethnic Disparities In Housing Instability During The Covid-19 Pandemic, Yung Chun, Stephen Roll, Selina Miller, Hedwig Lee, Savannah Larimore, Michal Grinstein-Weiss

Social Policy Institute Research

Stable and adequate housing is critical in the midst of a pandemic; without housing, individuals and families cannot shelter in place to prevent the spread of disease. Understanding and combating housing hardships in vulnerable populations is therefore essential to a sound public health response. This study aims to explore the pandemic’s disproportionate impacts on housing-related hardships across racial/ethnic groups in the United States as well as the extent to which these disparities are mediated by households’ broader economic circumstances; namely, their pre-pandemic liquid asset levels and the experience of COVID-19-related job and income losses. Using a national survey of over …

Bird Collision Mitigation Report Fall 2020, Alejandra Cohen, Brandon Trusler, Wade Wilson, Ian Mcwilliams

Sustainability Exchange

Bird Strike Mitigation Project Report for Sustainability Exchange, Washington University in St. Louis, Fall 2020

Esg Investing, Fall 2020, Juliet Kamau, Anthony Qiu, Brent Schiller, Raheem Williams, Ge Yu, Zixin Zhou

Sustainability Exchange

ESG Investing Project for Sustainability Exchange, Washington University in St. Louis, Fall 2020

Deicing Impacts On The Danforth Campus, Fall 2020, Lucy Armstrong, Kaela Evans, Kelly Fujimoto, Sydney Hornitschek, Genna Torgan

Sustainability Exchange

De-Icing Impacts on the Danforth Campus, Sustainability Exchange, Washington University in St. Louis, Fall 2020.

Charged Pore-Lining Residues Are Required For Normal Channel Kinetics In The Eukaryotic Mechanosensitive Ion Channel Msl1, Angela M. Schlegel, Elizabeth S. Haswell

Biology Faculty Publications & Presentations

Mechanosensitive (MS) ion channels are widespread mechanisms for cellular mechanosensation that can be directly activated by increasing membrane tension. The well-studied MscS family of MS ion channels is found in bacteria, archaea, and plants. MscS-Like (MSL)1 is localized to the inner mitochondrial membrane of Arabidopsis thaliana, where it is required for normal mitochondrial responses to oxidative stress. Like Escherichia coli MscS, MSL1 has a pore-lining helix that is kinked. However, in MSL1 this kink is comprised of two charged pore-lining residues, R326 and D327. Using single-channel patch-clamp electrophysiology in E. coli, we show that altering the size and …

“White Skin By Color, French Canadian By Métissage: Heredity Knows No Color”, Paula Y. Wilson

Arts & Sciences Electronic Theses and Dissertations

Abstract of the Thesis

“White Skin by Color, French Canadian by Métissage: Heredity knows no color”

Beta thalassemia (β-thalassemia) is one of the hereditary disorders unique to French Canadians (Braekeleer). This thesis argues for any correlations that may exist between the social and identity structures. These social and identity structures correspond with the close relationship between the French Canadians and β-thalassemia. The study reveals the specific cultural and linguistic isolation of these people and the principal cause of the distinguishing traits of this disorder as obscure amongst this ethnic group. French Canadians slowly but surely migrated from the French-speaking Providence …

Who Relocates, Where Do They Move, And Why?, Yung Chun, Jason Jabbari, Pranav Nandan, Andrew Foell, Michal Grinstein-Weiss

Social Policy Institute Research

The lack of socioeconomic mobility among marginalized populations leads to the concentration of poverty, a long-standing issue in American cities. Empirical studies on neighborhood effects have found that poverty concentration adversely affects the socioeconomic mobility of residents—associated with their economic well-being, employment, education, health, and safety—in lower-income neighborhoods. Through a variety of neighborhood revitalization projects, federal, state, and local governments have put enormous efforts into cutting the vicious cycle of poverty while increasing the socioeconomic mobility of lower-income households. One of these projects, the Choice Neighborhood Initiative, is a recent Federal effort to revitalize distressed public housing sites in American …

Asset-Building Policy In Korea: Innovation For Social Development, Michael Sherraden

Center for Social Development Research

This Perspective is adapted from Michael Sherraden’s keynote address given during the “Ceremony Commemorating the 20th Anniversary of Self- Sufficiency & Welfare Policy and 10th Anniversary of Asset- Building Policy” in Korea. The Perspective is presented through a partnership between the Center for Social Development, the Korean Ministry of Health & Welfare, and the Korea Development Institute for Self-Sufficiency & Welfare.

It Shouldn’T Take A Pandemic To Increase School Meal Access For Low-Income Students: A Two-Step Floating Catchment Area Analysis Of School Meal Access During Covid-19, Jason Jabbari, Yung Chun, Pranav Nandan, Laura Mcdermott, Tyler Frank, Dan Ferris, Sarah Moreland-Russell, Stephen Roll

Social Policy Institute Research

COVID-19 created an additional barrier for students who benefit from free school meals. While some schools attempted to provide alternative meal access points, many students lack adequate transportation. Thus, physical proximity to meal access points is particularly important during the pandemic. Taking into account both the “supply” and the “demand” for free meals, we employed a two-step floating catchment area analysis to analyze meal accessibility in St. Louis, MO. Overall, while meal access during the spring 2020 semester was substantially lower than the spring 2019 semester, meal access during the 2020 summer was substantially higher than the 2019 summer. Moreover, …

Income Loss And Financial Distress During Covid-19: The Protective Role Of Liquid Assets, Stephen Roll, Mathieu Despard

Social Policy Institute Research

Nearly a quarter of U.S. households have experienced job or income losses related to the COVID-19 pandemic. Liquid assets mitigate financial distress in the face of financial shocks such as job loss, yet this relationship in the midst of the COVID-19 pandemic is unknown. Using a nationally representative sample of U.S. households (N = 4,383) who completed a survey in the early days of the pandemic, we examined pre-pandemic liquid assets as a moderator of the relationship between job and income loss and difficulty meeting financial obligations and use of high-cost financial resources. Estimates from propensity score-weighted linear probability models …

Financial Capability And Asset Building In Social And Economic Development: Advancing The Sustainable Development Goals, David Ansong, Moses Okumu, Jin Huang`, Margaret S. Sherraden, Lissa Johnson, Li Zou

Center for Social Development Research

The concern for economic well-being undergirds most of the United Nations Sustainable Development Goals. This Perspective articulates an agenda for advancing those goals in resource-constrained countries by leveraging financial capability and asset-building (FCAB) strategies. It also specifies a role for financial technology (commonly called “FinTech”) in this work. The authors conclude with a call for better integrating FCAB and FinTech into plans for advancing the SDGs.

Thirty-Third Annual Bibliography 2019 (Mike Lützeler Contemporary German Literature Collection), Walter Schlect, Theresa Sambruno Spannhoff, Paul Michael Lützeler

University Libraries Publications

The 33rd bibliography of 717 volumes added to Washington University Libraries' Mike Lützeler Contemporary German Literature Collection. All published in 2019, these acquisitions include novels, poetry, short story collections, graphic novels, essays, autobiographical works, and literary and cultural periodicals from publishers in Germany, Austria, and Switzerland. Organized by author or editor, the bibliography includes local call numbers as well as subject and genre descriptors. This Collection serves as the research arm for the Department of Germanic Languages and Literature's Max Kade Center for Contemporary German Literature. A bibliography of items added the previous year is compiled each year …

Insights From State Treasurers: Developing And Implementing Statewide Child Development Account Policies, Chris Leiker, Margaret M. Clancy, Michael Sherraden

Center for Social Development Research

In 2018 and 2019, Pennsylvania, Nebraska, Illinois, and California enacted laws creating automatic, universal, at-birth CDA policies, and in 2020, the COVID-19 pandemic halted the progress of CDA bills in Missouri. Several states previously adopted CDA policies by administrative rule. This Policy Summary presents insights from four state treasurers based on their direct experience developing statewide CDA policy through legislation.

On July 16, 2020, the treasurers and other professionals gathered virtually for “All Children Can Reach Their Potential: A CDA Conference.” In a panel discussion moderated by Missouri State Treasurer Fitzpatrick, Pennsylvania State Treasurer Joe Torsella, …

Leadership Through An Indigenous Lens, Kelley Mccall

Buder Center for American Indian Studies Research

Indigenous leaders are found throughout history, across the globe. Indigenous leaders have been present long before European settlers colonized lands. These leaders possessed qualities, worked within frameworks, and created strategies to successfully lead their people and nations. For the purposes of this brief, examples used will be of American Indians/First Nations leaders.

Single‐Molecule 3d Orientation Imaging Reveals Nanoscale Compositional Heterogeneity In Lipid Membranes, Jin Lu, Hesam Mazidi, Tianben Ding, Oumeng Zhang, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

In soft matter, thermal energy causes molecules to continuously translate and rotate, even in crowded environments, thereby impacting the spatial organization and function of most molecular assemblies, such as lipid membranes. Directly measuring the orientation and spatial organization of large collections (>3000 molecules μm⁻²) of single molecules with nanoscale resolution remains elusive. In this paper, we utilize SMOLM, single‐molecule orientation localization microscopy, to directly measure the orientation spectra (3D orientation plus “wobble”) of lipophilic probes transiently bound to lipid membranes, revealing that Nile red's (NR) orientation spectra are extremely sensitive to membrane chemical composition. SMOLM images resolve …

Cash Transfers And Health, Sicong Sun, Jin Huang, Darrell Hudson, Michael Sherraden

Center for Social Development Research

Financial resources are known to affect health outcomes. Many types of social policies and programs, including social assistance and social insurance, have been implemented around the world to increase financial resources. As an overall term, we refer to these as cash transfers. In this article, we discuss whether, how, for whom, and to what extent purposeful cash transfers may improve health, both theoretically and empirically. The overall finding is that cash transfers are very positive, but as usual, there are many complexities and variations. Continuing research and policy innovation—for example, universal basic income and universal Child Development Accounts—are likely to …

Prototype Instrument Development For Measuring Directionality Of Aerosol Light Scattering, Esther K. Monroe

McKelvey School of Engineering Theses & Dissertations

Investigation of aerosol interactions with electromagnetic waves provides insights into the scattering particles. Aerosol phase function, an angular distribution of scattered light, is a value required to calculate parameters used in direct radiative forcing (DRF) models in the atmosphere. Currently no direct measurement of phase function is available hence it is estimated from ground observations such as backscatter fraction b and subsequently relating the parameters via Henyey-Greenstein (HG) approximation. This method has shown to introduce errors in radiation transfer models. HG phase function, in particular, does not account for particle microphysical properties such as shape and refractive index. Given the …

Schisms And Boundaries: Islamic Organizations And Sectarianism Between South Asia And Spain, Guillermo Martín-Sáiz

Arts & Sciences Electronic Theses and Dissertations

Since the September 11 attacks, numerous researchers—from security experts and political scientists to sociologists and anthropologists—have discussed how Islamic organizations establish within mosques across Europe and spread sectarianism among Muslims in the region. While these researchers have provided valuable insights, the dynamics that characterize the relationship between these mosques and organizations and the resulting sectarianism seem far from self-explanatory and remain rather unclear.

This dissertation focuses on how the intersections between global and local phenomena—the so-called War on Terror and Clash of Civilizations on the one hand, and urban transformations and gentrification on the other—shape support for—and opposition to—Islamic organizations …

Engineering Natural Competence Into The Fast-Growing Cyanobacterium Synechococcus Elongatus Utex 2973, Kristen Elizabeth Wendt

Arts & Sciences Electronic Theses and Dissertations

Synechococcus elongatus UTEX 2973 is the fastest growing cyanobacterium discovered to date. Using water, carbon dioxide, and light alone, this organism can double in 1.5 hours under optimal conditions. The accelerated doubling exhibited by Synechococcus 2973 makes it a prime candidate to serve as a model photoautotrophic system. However, Synechococcus 2973 lacks one highly desirable feature: it cannot undergo natural transformation. This thesis seeks to engineer this capacity into this fast-growing system in order to create an organism that is both fast growing and naturally competent. Synechococcus 2973 is a unique platform because it is >99% genetically identical to another …

A Mega-Analysis Of Personality Prediction: Robustness And Boundary Conditions, Emorie Danielle Beck

Arts & Sciences Electronic Theses and Dissertations

Decades of research suggest that personality is an important and robust predictor of life outcomes. However, previous investigations of personality-outcome associations have not adequately accounted for reverse causality and selection bias nor have they examined the boundary conditions of the effects, which has left the robustness conditions of personality-outcome associations unknown. The present study examines the robustness and boundary conditions of personality prediction using 14 personality characteristics to predict 14 health, social, education/work, and societal life outcomes across eight different person- and study-level moderators in 10 longitudinal panel studies in a mega-analytic framework coupled with propensity score matching to control …

X-Rays From Warped Black Hole Accretion Disks, Quincy Abarr

Arts & Sciences Electronic Theses and Dissertations

In this thesis, I present the results from my research to better understand accretion onto black holes and neutron stars based on spectropolarimetric X-ray observations.

I have developed a general relativistic ray-tracing code which simulates X-rays from warped accretion disks around black holes.

I used this to predict the polarization of the thermal X-ray emission and the energy spectrum the reflected power law emission.

Both of these can be used to measure properties of black hole systems, such as the spin parameter and the inclination of the observer to its spin axis.

My results enable the measurement of these parameters …