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iPhone-Based Image Refocusing
No full textIn this project, we show that we can change the focus of a picture after we take it by using real optical physics instead of fake software blur. Modern phones try to create “portrait mode” effects, but those results are often not physically correct. Our approach uses multiple photos taken from slightly different positions to figure out the directions that light rays came from in the scene.
To collect the photos, we move an iPhone sideways on a slider in small, precise steps. Since we know exactly how far the phone moved for each picture, we can track how objects shift across the images and estimate the angle of each light ray. With this information, we rebuild a 4D light field and use geometric back-propagation in MATLAB to move the virtual focus forward or backward. This lets us refocus on different objects at different distances.
We tested our method both in simulation (using a teapot scene) and on real iPhone photos taken in the library and outdoors at night. In all cases, the algorithm was able to shift the focus to different depths in a physically meaningful way. The results show that accurate, physics-based refocusing is possible using smartphone hardware as long as the camera positions are known.
This system can be expanded in the future by taking photos in a 2D grid, using all three iPhone cameras, improving sampling, and making the process fast enough to use in an iOS demo app
The Relationship between Agency Understaffing and Administrative Burdens in SNAP and Medicaid
No full textFor families trying to enroll in public programs to meet essential needs like food and health care, speed and timeliness can be critical. But people face numerous barriers in enrolling in these programs and in maintaining eligibility once enrolled. This research brief uses a new measure of staff workloads in public benefit agencies for every U.S. state and examines the link between these workloads and the experience of administrative burdens among low-wage workers. The analyses draw upon data from the Workforce Economic Inclusion and Mobility Survey
2D-Nanosilicate Carriers for Sustained Delivery of Vaccine Components
No full textLaponite® 2D Nanosilicates (NS) are disc-shaped platelets (~30 nm diameter, ~1 nm thick) with positively charged edges and negatively charged faces, capable of loading proteins, drugs, and nucleic acids via electrostatic interactions to form a house-of-cards gel that sequesters cargo. Here, we evaluated NS for sustained delivery of antigens and Toll-like receptor (TLR) agonists to extend germinal center duration and enhance antibody quality. The model antigen ovalbumin (OVA) was adsorbed onto NS at acidic pH in a ~1:1 ratio, with partial unfolding that remained stable at physiological pH. NS-OVA complexes were efficiently internalized by dendritic cells, with uptake driven primarily by clathrin-mediated endocytosis, raft engagement, and macropinocytosis. Antigen processing and presentation occurred through both MHC-I and MHC-II pathways, as demonstrated by inhibition studies and antigen presentation assays. Mechanistic analyses revealed dose-dependent cytotoxicity and inflammasome activation, including interleukin-1β (IL-1β) release at higher doses. In vivo imaging showed prolonged depot formation of NS-OVA at the injection site compared with free OVA, correlating with higher OVA-specific IgG titers following vaccination. RNA sequencing indicated modest early transcriptional changes (4 hours) and robust regulation at 24 hours in pathways related to interferon signaling, IL-1β, dendritic cell activation, and antigen processing. Overall, NS are safe and effective at enhancing antigen uptake, processing, and immune responses, supporting their potential as a vaccine delivery platform
FPGA-Accelerated Computational Photon Counting
No full textFluorescence Lifetime Imaging Microscopy (FLIM) is a powerful tool for biomedical re- search. It leverages fluorescence of biological samples to visualize and characterize biological dynamics and molecular interactions. FLIM utilizes fluorescence lifetime, the average time a molecule stays in its excited state after absorbing a photon, to investigate the dynamics of biological samples.
Ultra-fast and precise (ps-ns) timing fluorescence acquisition techniques suffer from different trade-offs. Some methods suffer from high dead times, decreased accuracy in fluorescence lifetime calculations, and high data volumes and transfers. Finding a new method that can provide the best performance while experiencing low dead times, adequate temporal resolution, and manageable data volumes, is integral to improving the functionality of FLIM. Single- and multi-photon peak event detection (SPEED) is a computational photon-counting method that has low dead times and high accuracy in fluorescence lifetime calculations. However, since the analog signal is digitized at high rates (5-10 GS/s), it suffers from the drawbacks that come with high data volumes, such as long transfer and processing times. To combat this, a data compression scheme on our field-programmable gate array (FPGA) is introduced and explored to reduce the amount of data transfers between our FPGA and CPU. Most of the data passed from the FPGA and CPU are zeros (95-99%) and the goal of the compression algorithm is to compress consecutive all zero data transfers to limit the total amount of data passed through the system. A three-state FSM was designed to implement the algorithm. The compression algorithm was analyzed in Verilog simulation and matched MATLAB simulations
Book Review: Police and the Empire City: Race and the Origins of Modern Policing in New York by Matthew Guariglia
No full textCriminologists often study the policing of racial minorities apart from the policing of immigrants. In Police and the Empire City, Matthew Guariglia takes this to be an analytical mistake principally because the two modes of policing show striking similarities. No less important, their respective histories in the United States appear to be intertwined and codependent. Guariglia advances these various arguments through a history of policing in New York City
Two Case Studies of American Classical Music Patronage in the 1980s and 1990s
No full textThis thesis examines how changes in the composition of classical music institutions’ funding bases in the 1980s and 1990s shaped their programming priorities and institutional behavior. Through two case studies—one focused on the Saint Louis Symphony Orchestra’s “In Unison” program and the other focused on Sybil Harrington’s philanthropic support of the Metropolitan Opera—it explores how individual and institutional funders used legal, financial, and symbolic mechanisms to exert influence over the music presented on symphonic and operatic stages. The first chapter argues that the Saint Louis Symphony’s community engagement efforts in the 1990s were shaped by the priorities of its public and private funders, particularly those promoting “neoliberal multiculturalism.” The second chapter examines Harrington’s use of restricted gifts, donor agreements, and social networking to promote traditional 18th- and 19th-century European repertoire. Together, these case studies highlight the extent to which classical music programming decisions are mediated by philanthropic agendas and show how scholars might study cultural patronage in recent decades, even in the absence of institutional transparency. Drawing from traditional archives, as well as court filings and press accounts, this thesis argues that understanding classical music institutions’ artistic output requires close attention to the funding structures that underwrite it
Black Scare, Red Scare: The FBI’s Covert War on Black Radical Activism
No full textBlack resistance movements have always existed to push the envelope and fight to establish political agency and freedom against the state and surrounding institutions that work to dispose of and disenfranchise Black communities across the U.S. The contentious relationship between the U.S. government and leftist movements is a rich and developed ground of scholarship analyzing how repression emerges and evolves across time as a tool against social movements fighting for change. This scholarship however misses how state agencies work to undermine and racially flatten Black radical movements through crafting official, racialized narratives and images that reshape what these movements represent. In the context of the FBI’s counterintelligence program (COINTELPRO) against Black Nationalists in the late 1960s, I analyze how the bureau discursively constructs Black activists as dangerous, immoral threats to society while activists themselves work to frame and establish themselves and what they stand for politically amid this period of repression. This project contributes to discussions of political repression on Black radical activism that has implications for scholars studying social movement repression by the state and for the wider public with the ongoing repression and counterinsurgency work enacted against Black movements today
Development and Validation of a Pronation-Supination Testing Protocol for Rat Elbow Joint Function
No full textPost-traumatic joint contracture (PTJC) of the elbow results in pain, stiffness, and loss of motion that can substantially impair daily function. While flexion-extension deficits in PTJC have been well characterized, the effects on pronation-supination remain poorly understood due to limited testing capability. The objective of this study was to develop and validate a method for quantifying rat elbow pronation-supination motion to better characterize elbow dysfunction. An existing load-controlled cyclic testing protocol was adapted using a rack-and-pinion system to convert linear displacement into forearm rotation, generating torque-displacement curves from which range of motion (ROM) and stiffness were evaluated. The protocol was optimized by reducing the applied force limit, increasing testing speed, and improving fixture alignment and repeatability. The updated method was validated by testing arthritis (CIA) and control (PBS) rat elbows. CIA elbows exhibited significantly greater total ROM and neutral zone length, as well as reduced stiffness compared to PBS elbows, somewhat consistent with prior findings in flexion-extension motion. These results demonstrate the effectiveness of the developed pronation-supination testing protocol and highlight the importance of evaluating multiple degrees of freedom to fully characterize elbow joint dysfunction. This method provides a critical tool for future studies investigating PTJC-induced functional deficits in the elbow
How Gas Flow and Distance from the Laser Focus Affects Powder Deposition Focus Concentration in a LENS Machine
No full textAdditive manufacturing via Direct Layer Deposition (DLD) is what the Laser Net Engineered Shaping or LENS machine is used to create components using metallic powders and a high powdered laser in the Flores Lab. In the lab this machine is used to create metallic alloys with high degrees of accuracy, but it has been difficult to get the accuracy required. By changing two variables, focus height and carrier gas flow rate, the concentration of the powder in a certain radius can be changed. The dot concentration and diameter were gotten using image analysis. It was found the LPM has a significantly larger impact on the dot diameter and concentration then the standoff distance, with 6 to 8 LPMs giving the best results. These results are useful, as they can be applied to achieve better and more consistent results in the lab
MEMS 4110: Extendable EV Charger
No full textThe Extendable EV Charger project set out to make a robotic mast that could extend to 4-5 feet and retract to less than 8 inches while support level 2 charging. The customer is Explication Automation, LLC, a local startup whose mission is to address the dexterity challenges people with disabilities face with manual EV charging. The most important customer needs are that the design is compact 6-8 inches, extends 4-5 feet, supports level 2 charging, and withstands harsh weather conditions. After iterative design with an initial prototype, the final prototype was designed using a linear actuator to extend custom made aluminum scissor links, housed within modular PLA parts, and sliding drawer rails to facilitate smooth extension and retraction. The prototype was evaluated using the following prototype performances goals: device goes from fully retracted (≤ 8 in) to fully extended (4-5 ft) in the horizontal plane and back again in under 1 minute, device goes from fully retracted to fully extended in the horizontal plane with ≥ 1 kg mass attached to the end and an axial compressive end load of ≥ 2.25 lb, and the device weighs ≤ 5 lb. Our final prototype design was a strong attempt but fell short of meeting the performance goals. Future improvements include optimizing the modular geometry for higher moment of inertia to reduce deflection of the extended mast, minimizing weight by developing a lighter sliding rail system, and reducing initial force required for extension by optimizing scissor link geometry