Compared to polymerase chain reaction with nasopharyngeal swab specimens, lateral flow assays (LFA) for detecting SARS-CoV-2 antigen in saliva are rapid, inexpensive, simple-to-use, and instrument-free, but have low sensitivity (ca. 11-40%) due to limited LFA sample capacities (ca. 50µL) and preparatory saliva sample dilution. To address this challenge, I developed an osmotic processor, a 3D-printed device, to concentrate target analytes through static and spontaneous osmosis for improving salivary-based COVID-19 LFA. The specimens loaded into the device were separated from an aqueous polymer solution using a dialysis membrane. The polymer solution with high mass polymer concentration resulted in an osmotic pressure difference that caused water transport from the saliva to the polymer solution, while the target analyte – SARS-CoV-2 nucleocapsid (N) protein – remained within the membrane. As the final solution contained the same N protein amount in a lower liquid volume, the overall sample was concentrated, thus improving the antigen detection limit ca. 60-fold, from 62.5 to 1 pg/mL. Combining the osmotic processor and saliva based LFA enables rapid, sensitive, simple, and inexpensive POC testing.

According to the Corruptions Perception Index, Nepal is ranked 117 out of 180 countries for corruption with 12% of public service users having paid a bribe in the last 12 months. While many studies have analyzed systemic corruption within Nepal, little research has attempted to measure the magnitude of systemic corruption, with particularly limited literature on systemic healthcare corruption. To estimate the prevalence of petty systemic healthcare corruption (i.e. between the public and low-level public officials or doctors), I designed a survey guided by prior United Nations Office on Drugs and Crime and European Commission research, and a series of interviews with Nepalis. Bir Hospital was randomly selected among 5 other public hospitals in Kathmandu, and I administered the survey to 41 participants over two days. 43.2% of respondents paid more than they expected, and 68.6% of these respondents felt this payment was outside of their cultural norms. Moreover, 41.7% of the respondents paid cash directly to a doctor, which interviews indicated is atypical. No correlation was found between income and how respondents rated their care; moreover, no statistical significance was found using a t-test between how respondents rated their care and whether they paid cash directly to a doctor. However, odds ratio analysis on whether a payment was outside of cultural norms and whether the desired care was received yielded a ratio of 1.23, indicating that these payments mildly increased the probability of getting the desired care. This, paired with interviews indicating distrust of the hospital system and prior research demonstrating corruption throughout Nepal suggests systemic healthcare corruption in the form of bribes is prevalent, but does not necessarily guarantee better care. Further research must be done to not only determine the efficacy of this survey method, but also the validity of this model.

Over the last decade-and-a-half, China has seen its financial technology (fintech) industry achieve a level of scale and ubiquity without peer among developed economies — Alibaba’s Alipay and Tencent’s WeChat Pay, to name a few examples, each enjoy over one billion users, and are deeply integrated into daily life. Yet, by its hybrid nature, fintech presents complex challenges novel to both financial and technology regulation, the dramatic collapse of China’s peer-to-peer lending industry being a case in point. In this context, as much as Chinese firms lead the way in fintech development, Chinese regulators also act as innovators in the yet-undeveloped field of fintech regulation. As such, the study of the Chinese regulatory experience may yield insight into how other nations may develop their own regulatory frameworks towards fintech as an emerging industry. This research investigates the characteristics and challenges of Chinese fintech regulation. Specifically, this research considers the current institutional approach to regulation, the financial risks that current regulation seeks to address, and the effects of said regulation on the fintech industry. Given the novelty of fintech as a regulatory field, this research addresses a new and developing niche within the broader study of Chinese economic policymaking. I utilize a combination of general policy analysis and case study of specific regulatory actions to analyze both the regulatory process and its effect on the fintech industry. Qualitative analysis of regulatory documents and materials is complemented by quantitative analysis of industry-level data in examining both regulatory initiatives and their empirical economic effects upon fintech firms.This research is expected to yield the result that, because of its novelty and intersectionality, Chinese fintech regulation is underdeveloped relative to traditional finance or technology regulation. Simultaneously, this research is also expected to indicate a general trajectory towards greater regulatory scrutiny towards fintech firms.

Clearance of wound infections can be hindered by a bacterial biofilm; a complex extracellular matrix (EM) secreted by adherent bacteria that allows them to evade the host immune system and obviate antibiotics. A novel, synthetic peptide—known as an anti-α-sheet inhibitor—can disrupt biofilm stability by inhibiting the formation of amyloid fibrils, which contribute to the biofilm EM. This project aims to design and characterize alginate porous scaffolds that elute these synthetic peptides, for use as anti-biofilm wound dressings. The physical properties and peptide release kinetics of the scaffolds will be optimized for clinical applications, supported by in vitro efficacy studies with live bacteria. This project draws upon past work from the Bryers Research Group on engineering infection immunity and tissue scaffolds, in which biofilms are prevalent. Results of this project will provide an alternative approach to biofilm prevention, thus reducing the burden of biofilm-related infection complications.

Effective rapid tests have been developed to detect COVID-19 in nasal swabs. However, nasal swabs require a trade-off in which deeper insertion of the swab allows higher accuracy but causes greater patient discomfort. On the other hand, saliva can be collected non-invasively in large volumes. Therefore, this project aims to develop a point-of-care diagnostic device (“DiagnosDisk”) for the rapid and sensitive detection of SARS-CoV-2 nucleocapsid protein (NP) in saliva. The DiagnosDisk is a circular disk (25mm diameter) consisting of three layers, from top to bottom: a plastic adhesive capping sheet with a sample port, a hydroxylated nylon detection membrane, and an absorbent pad. Analytes are efficiently enriched by binding to anti-NP antibodies conjugated to temperature-responsive polymers (poly(N-isopropylacrylamide)) which aggregate upon heating. To prepare the sample, polymer- and gold-conjugated antibodies are mixed with the sample and bind to the target antigen, forming a sandwich immunocomplex. When flowing through the heated detection membrane (>37℃), the sandwich immunocomplexes aggregate and are captured on the membrane, producing a visual signal. I quantify the signal intensity on the membrane using ImageJ software. With this design, I hypothesize that the DiagnosDisk will have higher sensitivity than the lateral flow assay (LFA) by utilizing temperature-responsive polymers for sample enrichment and using larger sample volumes which increases the number of antigens that can be captured. From my initial testing, the DiagnosDisk enabled 2mL of buffer flow-through in 7.5 minutes, demonstrating a sample volume capacity 10-times that of most LFA. Next, I tested the DiagnosDisk with buffer samples spiked with 5ng/mL NP. Heated membrane pads produced signal intensities significantly greater than unheated membranes. I plan to apply the device to saliva samples next. Ultimately, by enabling rapid and sensitive detection of COVID-19 in saliva, the DiagnosDisk can help limit community transmission of the virus.

Reproductive and developmental toxicology is an area of importance for public health. Current in vivo methods of reproductive and developmental toxicity testing require large cohorts of animals, lengthy experiment times, and high cost. In vitro models using cultured cells align with the three R’s of toxicology: to replace, reduce, and refine the use of animals in toxicity testing. Our group is developing an in-vitro model of neonatal testis to study developmental testis toxicity while reducing animal use. To test the physiological relevance of our in-vitro model, I collected post-natal day five testis for immunohistochemical analyses. I dissected the testis from the surrounding tissue, fixed the tissue in formaldehyde solution, and left in a sucrose solution overnight. The fixed tissues were then frozen for cryosectioning. I sectioned the frozen tissue into 20µm sections using a cryostat and adhered them to microscope slides. To improve staining, I washed the adhered samples and permeabilized the membranes with detergent. I incubated each sample with fluorescent antibodies to target functional proteins and cell type markers. To visualize the targets of interest in the tissue sample, I used a confocal microscope to generate stacks of images through each section. I will next perform the same staining procedure on the in vitro culture samples for comparison. My poster presentation will present confocal microscopy images showing localization of these functional and cell type markers. These images will provide a comparison to our group’s in-vitro models. These images also give insight to healthy testis formation which can be compared to abnormalities in future pathological studies.

Myotonic dystrophy type 1 (DM1) is a genetic disease that causes many serious health conditions in a variety of tissues including skeletal muscle stiffening, weakness, and degeneration. DM1 is caused by a CTG repeat expansion mutation in the myotonic dystrophy protein kinase gene, DMPK. Expression of the mutated DMPK allele binds with the splicing regulator muscle-blind-like 1 (MBNL1), causing DM1 by sequestering and limiting its critical role in splicing mRNA. A main focus of the Chamberlain lab is the development of gene therapy to treat DM1, including increasing protein expression of MBNL1 to reduce the disease effects in muscle. Overexpression of MBNL1 in skeletal muscle could be beneficial but may have negative effects on cardiac tissue. The lab discovered that high, unregulated MBNL1 expression from gene therapy vectors in cardiac tissue can result in cardiac damage. In my study, I will focus on cardiac function when testing adeno-associated viral vector (AAV)-mediated systemic delivery of the MBNL1 gene to increase MBNL1 protein expression in muscle. Using analytical methods such as echocardiography and tissue histological techniques, I will determine whether it is possible to prevent MBNL1 protein production and its damaging effects in the heart while still expressing MBNL1 protein in skeletal muscle for therapeutic disease benefits.

Lignocellulosic biomass, composed of cellulose, hemicellulose, and lignin, has become an attractive renewable carbon source for microbial bioproduction of value-added chemicals. Lignin is relatively difficult to depolymerize, and its enzymatic hydrolysate contains mostly aromatic compounds known to inhibit microbial growth when used as a carbon source. Pseudomonas putida (P. putida), a soil bacteria known for its tolerance to aromatics, has been engineered to catabolize lignin hydrolysate. Engineered microbes have also been encapsulated in hydrogels for on-demand bioproduction and exhibited enhanced tolerance to harsh processing conditions, i.e. freeze-drying and exposure to organic solvents. This research aims to create microbe-laden hydrogels from encapsulating engineered P. putida KT2440 cells in F127-bisurethane methacrylate (F127-BUM) hydrogels for robust on-demand bioproduction when using lignin hydrolysate as a substrate. To mimic growth rate inhibition that often happens in hydrolysate environments, we first examine if P. putida-laden hydrogels remain active when grown in a less-ideal medium, such as M9 minimal media (MM9) known to yield a slower microbial growth rate. We find that hydrogel-encapsulated P. putida containing a plasmid for heterologous expression of a green fluorescent protein (sfGFP) maintained its activity in MM9 continuous culture over two days as measured via fluorescence of the expressed sfGFP. This preliminary result on encapsulated P. putida growth and activity in a less desirable culture environment highlights the potential for utilizing aromatics-rich lignin hydrolysate in bioproduction as a more economical and renewable feedstock alternative.

Engineered genetic circuits provide an environmentally friendly path to chemical industries, including fine chemicals and therapeutics. To effectively modulate genetic circuits, a programmable tool to control multiple genes is necessary. CRISPR-mediated gene activation (CRISPRa) is an emerging tool suitable for this purpose. In CRISPRa, a nuclease-deficient dCas9 protein is used to deliver a transcriptional activator domain (MCP-SoxS) upstream of genes of interest. A complementary guide RNA (gRNA) enables dCas9 recruitment to any DNA target. Despite the programmability of CRISPRa, the number of genes that can be simultaneously regulated remain unexplored. In this work, we aim to experimentally investigate the number of gRNAs limitation in the chemical bioproduction context. First, we designed CRISPRa circuits with an increasing number of guide RNAs encoded on plasmids constructed with a scalable and high-throughput technique via Golden Gate Assembly. CRISPRa circuit performance was then evaluated by simultaneously regulating multiple fluorescent proteins as a proxy for multi-enzyme cascade in biosynthetic pathways. Increasing the number of gRNAs was found to decrease CRISPRa activity, suggesting competition of CRISPRa components. Furthermore, we applied the constructed circuits for metabolically engineered pathways in P. putida regulating production of p-aminocinnamic acid (pACA), a precursor for polymer synthesis vital in photovoltaic and biomedical applications. Bioproduction of pACA in P. putida was enabled by simultaneously regulating 9 heterologous genes. The outcome of CRISPRa circuits will be analyzed via High-Performance Liquid Chromatography (HPLC).The implication of this work will allow us to construct large scale CRISPR genetic circuits and optimize multi-gRNA CRISPR circuit integrations into other systems such as non-model organisms and cell-free systems, which will expand metabolic engineering capabilities and chemical productions beneficial in a wide range of biosynthetic applications.

Current smart home devices understandably prioritize the needs of a primary user/owner, who is also typically the purchaser of the device and a corresponding subscription plan. Yet smart home cameras and other smart devices with microphones, location tracking, and other spatial sensing capabilities invariably impact the privacy of people nearby, such as family, friends, guests, neighbors, and domestic workers. We refer to these affected nearby people as adjacent users (or adjacent subjects) because they may interact with smart devices but do so with relatively little or no direct awareness, consent, access, control, or benefit. Although work in privacy and security has begun to address the privacy needs of adjacent users, there is little design research that has responded with either concrete interventions like proposals or prototypes. We present a novel speculative design of a smart home camera called Arca with a physical camera prototype and a mobile application. A significant insight of our empirical and design research is that the most common issues with smart camera privacy is the interpersonal tensions and conflicts stemming from inadequate disclosure, consent, autonomy, and transparency from primary owners. Whereas traditional privacy/security research often focuses on harms from improper disclosure of personally sensitive information, our research suggests that many adjacent users do not necessarily mind being recorded, they do mind the lack of “communication,” “respect,” and “professionalism” from primary users. Furthermore, our studies reveal that even if our specific privacy modes and access sharing features are not regularly used, they may nonetheless function as mechanisms to facilitate better, more open conversation between primary and adjacent users. We continue our work with the goal to enhance adjacent user privacy and experience with privacy-sensitive camera features and reduce tension between adjacent users and primary users.

Titus Livius, better known as Livy, was a Roman historian writing at the beginnings of the Augustan age and the fall of the Roman Republic. Livy wrote his magnum opus, Ab Urbe Condita, as a moralizing history in response to the moral degradation and civil strife he experienced during the collapse of the Republic. The first seven chapters of Book I outline Roman prehistory before Romulus’s reign and contain several imitations and allusions to archaic poetry and Classical historiography. Livy himself believes that the subject of his writing would have been better suited for poetry than prose. This project aims to provide quantitative evidence for Livy's claim by quantifying and analyzing instances of literary devices of earlier poetry such as alliteration and etymologizing to determine whether a poetic influence is implicit in Livy’s prehistory of Rome. Preliminary results based on the quantity of alliteration present in Livy's writings suggest some influence by earlier poetic sources. However, it is difficult to substantiate any conclusions on statistical grounds due to fragmentary literatures. Instead, this project also proposes further hypotheses about source accessibility and poetic inclination that may explain the quantitative phenomena.

Creative coding refers to a method of computer programming that prioritizes artistic expression. Remixing is the iterative behavior of altering an existing artifact. Frameworks such as p5.js support sketching with creative code. Given the focus on expressivity over functionality, code reuse in creative coding practice is distinct from other programming contexts. Additionally, remixing facilitates iteration on existing code, but we have yet understand how creative coders use remixing in practice. To understand creative coder remixing strategies, we studied the community of OpenProcessing, a site dedicated to sharing code-generated artworks. To begin, we conducted a network analysis to determine which datasets of original sketches (also referred to as the antecedent sketch) and their remixes to use in our study. Our visualization consisted of a social network graph in which the nodes represent individuals, and edges showing their relationships. We found that 30% of the 1.2 million sketches in our dataset were involved in remixing. For data analysis, we utilized a code-diff tool to showcase ways the antecedent sketch's code differs from the remix and categorize various types of remixing strategies. Over time, these categories became increasingly focused on changes made visible on our code-diff tool. We present on the diversity of ways that authors remix to curate projects, annotate process, explore variations, and transform existing sketches. Through remixing, artists have already begun to tailor, customize, and explore different ways to use their creative tools, in ways system developers may not have foreseen. We find that remixing also encourages exploratory programming and experiential learning. As creative code is increasingly used to support computational education, we can consider the implications of remixing for understanding and facilitating informal learning. At last, we reflect on the prevalence of these remix types and how future systems could support a multiplicity of remixing strategies for creative work.
 

Massive stars place powerful constraints on stellar evolution and are observed in a menagerie of exotic evolutionary phases. These objects play a crucial role in regulating their environments. They drive the chemical evolution of their host galaxies, and set the energy balance of their surroundings via feedback processes. Due to the importance of massive stars, placing constraints on their evolution serves as a key to understanding galactic ecosystems. Notably, stellar variability is a powerful probe of the poorly-constrained physics of massive star evolution. In particular, variability studies on ensembles of evolved massive stars can significantly constrain stellar evolution. We aim to understand the variability of hot massive stars through a census of these objects. We accomplish this using data from the Gaia mission, cross-matched with light curves from the Zwicky Transient Facility (ZTF). We expect to characterize the evolution of massive star variability timescales and amplitudes along the main sequence and beyond. Our results will place key constraints on the evolution of massive stars. 

Previous studies have indicated that the neurohypophyseal hormone, oxytocin (OXT), reduces body weight in high fat diet (HFD)-induced obese (DIO) rodents, nonhuman primates and obese humans through reductions in food intake and increases in energy expenditure. Findings from recent pre-clinical and clinical data indicate that the long-acting glucagon-like peptide 1-receptor (GLP-1R) agonist, semaglutide, reduces body weight, in part, through reductions of food intake. Based on these findings, we hypothesized that the combined treatment of OXT and semaglutide would produce an additive effect to evoke weight loss in DIO rats. To test this hypothesis, rats were fed a HFD for approximately 5 months prior to being implanted subcutaneously with a 28-day minipump that infused OXT (50 nmol/day) or vehicle (VEH; saline). Data from animals that received escalating doses of the incretin hormone, glucagon-like peptide-1 (GLP-1) and semaglutide was analyzed over the 32-day infusion period. Daily energy intake and body weight were tracked for 32 days. Body composition was assessed immediately prior to onset of treatment and near the end of the treatment period using Quantitative Magnetic Resonance (QMR; EchoMRI 4-in-1). OXT (50 nmol/day) alone and semaglutide (3 nmol/kg) alone reduced body weight by approximately 9.9±1.1% (0.05<P<0.1) and 4.3±1.4% (P<0.05), respectively (N=6-7/group), relative to pre-infusion baseline, while GLP-1 at either dose (1 or 3 nmol/kg, SC) was ineffective (P=NS). However, the combination of OXT and semaglutide (3 nmol/kg) produced a more pronounced reduction in body weight (14.1±1.4%; P<0.05) compared with either treatment alone (N=6-7/group). These effects were associated with reduced energy intake, adiposity and adipocyte size (P<0.05). Together, these findings support the hypothesis that the combination of OXT and the GLP-1R agonist, semaglutide, produces an additive effect to evoke weight loss and body adiposity in DIO rats by reducing energy intake. Our findings will create a preclinical infrastructure upon which future studies are undertaken to address whether oxytocin may be used as an adjunct with other treatment approaches, including low doses of the FDA-approved GLP-1R agonist, semaglutide, to evoke weight loss in humans with obesity.

Oral tolerance to antigens is a mechanism by which immune responses are inhibited to prevent chronic inflammation and tissue damage in response to common exposures, such as dietary antigens or commensal bacteria. Regulatory T cells (Tregs) are an important cell type in such regulation of immune responses, especially in the intestines. There is, however, heterogeneity within Tregs, including a subset that expresses the transcription factor RORgt. However, the mechanisms by which RORgt+ Tregs carry out their suppressive function are currently unknown. Intestinal Tregs are induced in the mesenteric lymph nodes (MLNs) by antigen-presenting dendritic cells (DCs) that migrate from the gut. Antigen transfer from DCs to Tregs is crucial for the development of oral tolerance and DCs are largely regarded as being upstream of Tregs. However, it has also been shown that Tregs play a role in DC migration via a CTLA-4-mediated mechanism. Because this DC-Treg relationship is not fully understood with regard to Treg heterogeneity, I have examined the changes in DC populations in a mouse model where the RORgt+ Treg population alone has been ablated. To do this, I developed a new panel of antibodies to use in flow cytometry in order to characterize the subpopulations of DCs in the intestines and related organs. I harvested and processed murine spleens, MLNs, Peyer's Patches, and small intestine lamina propria in order to compare the populations systemically and locally. I anticipate seeing fewer DCs in the mice lacking RORgt+ Tregs and more DCs in the small intestine and Peyer's patches. This work furthers our understanding of the intricacies of the intestinal immune system. This knowledge can be applied to vaccine research, as RORgt+ Tregs have been implicated as suppressors of immune response to oral vaccines. Intestinal immunity is also of interest in allergy and gut inflammation research.