19468 research outputs found
Sort by
Designing, Constructing, and Testing of a Dual Fluorescent Genetic Circuit for Mycobacteria Promoter Characterization
No full textMycobacterium is a large genus of bacteria that are ubiquitous and diverse. While most members of the genus are non-pathogenic, a few species such as Mycobacterium leprae and Mycobacterium tuberculosis are responsible for fatal diseases such as leprosy and tuberculosis. Other species such as Mycobacterium neoaurum, Mycobacterium smegmatis are used for the industrial synthesis of chemicals such as sterols, and Mycobacterium smegmatis is a good platform to study tuberculosis. Mycobacteria also have clinical applications such as vaccine production and drug screening. Synthetic biology can further the study and application of mycobacteria by designing sophisticated genetic circuits. To design functional circuits, quantitative modeling is critical for researchers to select the proper genetic parts. However, mycobacteria lack a comprehensive promoter library that quantifies promoter characteristics such as promoter strength, induction, and repression. This study aims to construct a promoter library for mycobacteria using a dual fluorescence circuit pSUM7. We have designed and constructed pSUM7 that expresses mCherry while having an insertion site for a test promoter that drives the expression of sfGFP. Based on pSUM7, we have constructed genetic circuits to test 18 different promoters from Mycobacterium smegmatis. We then successfully transformed the test circuits into M. smegmatis, and the fluorescence was measured. Ultimately, problems and limitations of the test circuits such as the use of the sfGFP gene and low plasmid vector copy number are identified and solutions are proposed. The ultimate goal is to develop a standard quantitative method to characterize M. smegmatis promoters and construct a comprehensive promoter library.BiologyBachelors of Science (BS
The Development of an AI Video Laryngoscope
No full textThis thesis introduces a video laryngoscope with improved visibility and an AI guidance system. The laryngoscope is equipped with a camera and can automatically stream live video taken during intubation to a server through WiFi that is accessible to any device connected to the same WiFi station (router, hotspot, etc.). It is also compatible with devices with Bluetooth Low Energy (BLE) and can thus establish paired communication with most of the electronic devices on the market. The backend of the AI guidance system is a neural network trained for image segmentation. Our most recent model uses a new network architecture to identify the vocal folds in the laryngoscope’s video feed with high accuracy and inference speed.PhysicsBachelors of Science (BS
The Development of an AI Video Laryngoscope
No full textThis thesis introduces a video laryngoscope with improved visibility and an AI guidance system. The laryngoscope is equipped with a camera and can automatically stream live video taken during intubation to a server through WiFi that is accessible to any device connected to the same WiFi station (router, hotspot, etc.). It is also compatible with devices with Bluetooth Low Energy (BLE) and can thus establish a paired communication with most of the electronic devices on the market. The backend of the AI guidance system is a neural network trained for image segmentation. Our most recent model uses the CCNet architecture to identify the vocal folds in the laryngoscope’s video feed.PhysicsBachelors of Science (BS
Contradictory Connections: Commercial Currents and Political Perspectives of Haitian Independence in the U.S. South
No full textOn January 1, 1804, Haiti declared independence from France, becoming the first Black-led nation outside of Africa and a country whose creation was the culmination of the most successful slave revolution in history. Haiti’s independence underscores what scholar Marlene Daut calls the “1804 Principle,” or the idea that “racism, colonialism, and slavery are the greatest evils of any time.” But Haiti’s nationhood depended on its commercial recognition by the Atlantic world’s other nations; nations that promoted the racism, colonialism, and slavery that the new Haitian state opposed. This thesis explores the tensions of Haitian mercantile relations in one of those slave-holding spaces: the United States South. It argues that commercial recognition in the U.S. South varied by geographic location. In the Upper South, Baltimore, Maryland, was Haiti’s top trading partner between 1804 and 1806. At the same time, Charleston, South Carolina, saw a dramatic decrease in ships trading with Haiti between 1803 and 1805. In 1803, 57 ships arrived in the South Carolina port from Haiti. In 1805, only three ships came from the Black nation. Political leaders in South Carolina reconciled their desires to spread slavery with their fears of the Haitian Revolution. As a result, white South Carolinians viewed Haiti through a more racially sensationalist lens before the United States officially interdicted trade with the country in 1806. While people in the Deep South viewed Haiti through a primarily racially sensationalist lens, Haiti conjured a more complex image in the Upper South. In places like Baltimore, Haiti represented economic opportunity, and the city’s merchant community went through great lengths to continue trading with the country.HistoryBachelors of Arts (BA
“Protect Black Women”: Narratives of Black Women’s Experiences with Police
No full textAs discussions surrounding police violence against Black individuals continue, there is a noticeable lack of focus on the experiences of Black women. This project uses narratives to bring attention to their stories because in order to address the issue of police violence, it is essential to understand its full scope. Storytelling can also inspire social change as it can influence how people view society and encourage people into action. This project follows the history of the police and its impact on Black women to inform current conversations about the institution. This project also argues abolition is essential to ending police violence and discusses what that entails.GovernmentBachelors of Arts (BA
Design and Partial Assembly of a Promoter Characterization Circuit for Mycobacteria
No full textMycobacterium is a diverse genus of gram-positive, aerobic bacteria known for their waxy cell membrane, resilient biofilms, and harmful pathogens. Bioengineering has enabled their use in a variety of fields. Mycobacteria have been engineered as vaccines and to gain insight into their pathogenesis. Species like Mycobacterium neoaurum are currently the only bacteria used at the industrial level to synthesize sterols for various therapeutic uses. Finally, mycobacteria in soil have been shown to break down highly stable pollutants, while their aquatic counterparts have been suggested as “probiotic” coatings in plumbing. All of these applications of mycobacteria could be expanded beyond their current state with synthetic biology by promoting rational design, system modeling, and standard genetic part characterization. However, mycobacteria lack the fundamental underpinnings of standard genetic parts to model and assemble genetic circuits with. We have designed and partially assembled a promoter characterization method to characterize promoters in mycobacteria in a standard, highly qualitative manner. The genetic circuit pSUM7 constitutively expresses mCherry while simultaneously expressing sfGFP, which is regulated by a test promoter. Ultimately, we plan to generate a comprehensive promoter library from which synthetic biologists can select promoters a la carte that best fit their modeling parameters and design goals. This will help lay the foundation for synthetic biology in mycobacteria and rational circuit assembly.BiologyBachelors of Science (BS
Diversity on DoG Street: The History of Black, Indigenous, and Queer Communities’ Representation at Colonial Williamsburg and William & Mary’s Historic Campus
No full textDespite composing over fifty percent of the population in colonial era Williamsburg, marginalized communities are historically underrepresented in the textual content, artifacts, programming, and staffing of museum spaces along Duke of Gloucester (DoG) Street. This thesis, “Diversity on DoG Street: The History of Black, Indigenous, and Queer Communities’ Representation at Colonial Williamsburg and William & Mary’s Historic Campus,” is a study in the current and historical state of marginalized communities’ representation, involvement, and inclusion in the museum field using Colonial Williamsburg and William & Mary’s Historic Campus as a case study. It answers the question “How have marginalized communities, specifically Black, Indigenous, and Queer Communities, been portrayed in Colonial Williamsburg and on William & Mary’s Historic Campus?” using corporate archives, interviews with employees, online descriptions of programs, news articles, and secondary sources.HistoryBachelors of Arts (BA
Legitimizing the Myth of the Nation: Mass Media Historical Writings on Qigong Fever in Mainland China between the 1980s and the 2020s
No full textHow could popular history presented in post-Mao Chinese mass media settle the state’s emerging ideological and sociopolitical tensions and satisfy different historical agents’ multi-level interests? Existing scholarships take a top-down approach by emphasizing how the Communist Party of China (CPC) ’s regulations on mass media industries restricted the historical narratives they produced. Alternative accounts focus more on how Chinese mass media’s diversification and marketization since the 1980s have given agents more opportunities to produce appealing historical accounts that potentially touch on controversial contemporary issues. By employing unexamined Chinese mass media sources and state-level archives, this Honor Thesis studies the mass media historical writings of qigong fever氣功熱 – a mass-organized qigong practicing movement that prevailed in China between the 1980s and the 1990s. It argues that these writings legitimized the fever as a symbol of China’s national revival under the CPC’s leadership to reconcile the tension between tradition, modernization, and the Party in post-Mao China. It also analyzes how these works’ authors – known as mass media historians – actively used the writings to achieve their pursuits of readership, political security, and career benefits. By doing so, the thesis expands the concept of mass media historians in post-Mao China by placing the term in the middle of the “state-public” dichotomy and the writers’ interpersonal networks. It ultimately seeks to reveal how different agents’ considerations and powers in post-Mao China interplayed under a centralized regime’s heavy regulations and how these interplays reproduced knowledge of the past and the present to diverse groups of readers.HistoryBachelors of Arts (BA
Comparison of garbenschiefer fabrics and regional deformation features in the Chopawamsic terrane of Virginia
No full textGarbenschiefer, a type of amphibolite with large, radiating, feather-like amphibole porphyroblasts among a finer-grained, recrystallized matrix of plagioclase and quartz, has been identified and mapped by Brown (1969) in the Chopawamsic terrane. Previous research on garbenschiefer in Virginia has focused on evaluating if "hornblende gneiss with pattern" identified by Brown (1969) could be considered garbenschiefer through mineralogy and textural observations as well as geochemical analysis to characterize the protolith of these rocks (DeCourt, 2013; Owens and DeCourt, 2014). This project aims to investigate orientations of amphiboles defining garbenschiefer fabrics, and determine their relationship to the larger tectonic history of the Chopawamsic terrane, in particular as a function of their proximity to large-scale deformation features. I hypothesize that garbenschiefer closer to shear zones or faults will have amphiboles that show a greater preferred crystallographic and shape orientation which would reflect greater strains, compared to garbenschiefer located farther away. Three samples were analyzed to assess the overall orientation and strength of the garbenschiefer fabric defined by amphibole. X-Ray Computed Tomography (XRCT) was used to characterize the shape preferred orientation of amphibole. Anisotropy of magnetic susceptibility (AMS) was used to measure the average crystallographic alignment of amphibole following the method of Biedermann et al. (2018). Amphibole grains in garbenschiefer samples for this study are subidiomorphic therefore, grain shape and crystallographic axes should be coincident. Results from the XRCT data using the SLD method (Ketchum, 2005) show that the samples range from oblate (shape parameter U modified from AMS, U = 0.06) to prolate (U = -0.62) for the amphibole fabric and oblate (U = 0.33) to prolate (U = -0.11) for the oxide fabric. Results from low-field AMS data show that samples range from oblate (U = 0.06) to prolate (U = -0.39) representing either the amphibole and/or oxide fabric. High and low temperature magnetic susceptibility measurements indicate that the AMS in one sample is dominated by paramagnetic minerals, and by ferromagnetic minerals in the other two samples. The low-field AMS results for the ferromagnetic samples cannot be interpreted as representing amphibole fabrics, but are rather interpreted as reflecting the shape preferred orientation of magnetite. Even though samples have different magnetic carriers, they both provide information about the three-dimensional geometry of mineral alignment in these samples. The magnetic data is interpreted using crystal shape data obtained by XRCT to ‘ground truth’ and investigate the significance of the magnetic fabric data.GeologyBachelors of Science (BS
Counterion Dependent Coordination in Complexes of Divalent Group 12 Metals with Organic Ligand Tris[(6-methyl-2-pyridyl)methyl]amine
No full textComplexes of type [M(TLA)Cln](ClO4)2-n (TLA = tris[(6-methyl-2-pyridyl)methyl]amine) have been isolated and characterized by X-ray crystallography and NMR for M = Zn, Cd, Hg and n= 1, 2. Across all three M, the metal-ligand binding motifs depend on n. When n = 1, TLA is tetradentate with all three of the pyridyl nitrogen binding sites coordinated to M. M is five or six coordinate, coordinated to four amines and one or two chlorides. When n = 2, one of the three pyridyl amines of TLA does not bind and the pyridyl ring is positioned away from the coordinated chlorides. M is five coordinate, coordinated to three nitrogen and two chlorine atoms. Crystalline structures are stabilized by offset face to face pi stacking. Despite coordination differences in crystal structures, solution state NMR suggests that complexes of n=1 and n=2 are similar in solution. This thesis expands understanding of group 12 metal coordination in varying chemical environments, with biological and crystallographic applications.ChemistryBachelors of Science (BS