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Inhibition of Quorum Sensing in Pseudomonas aeruginosa through the PqsE Active Site
No full textPseudomonas aeruginosa is a multi-drug-resistant pathogenic bacterium, meaning that most antibiotics cannot treat infections caused by these bacteria. With a lack of novel antibiotics coming into circulation, P. aeruginosa is a threat to global health amid the current antibiotic resistance crisis. P. aeruginosa utilizes a cell-to-cell communication mechanism called quorum sensing in order to produce toxins and form multicellular communities called biofilms. Quorum sensing in these bacteria depends on the interaction between the proteins PqsE and RhlR. Inhibiting this protein-protein interaction could turn off quorum sensing and allow P. aeruginosa infections to be more easily treated. This research project explored two methods of drug discovery: structurally-informed ligand derivatization and high-throughput screening to identify molecules that could potentially inhibit this quorum-sensing ability and allow for new methods to treat P. aeruginosa infections. This work led to the synthesis and evaluation of five novel PqsE inhibitors and the identification of three FDA-approved molecules from the screening process for further analysis.ChemistryBachelors of Science (BS
Stereotype Content at the Intersection of Race and Sexual Orientation: Black Lesbians
No full textWith queerness and feminism equated with whiteness and racial movements focused on men, Black lesbians suffer from an erasure of experience and invisibility (Nash, 2008). The current study utilized an intersectional perspective (Crenshaw, 1989; Harnois, 2014) to examine racial and sexual stereotypes as applied to Black and White lesbians and Black and White straight women. This work explored how the social categorization of race and sexuality culminates in unique stereotypes that may have implications for the discrimination they experience. College student participants (n = 125) viewed lesbian and straight Black and White female faces and identified either the sexuality and race of each face followed by a stereotype identified in the Facet Model (Abele et al., 2016) within the framework of agency and communion. Stereotype activation was analyzed with a 2 (Target race: Black, White) x 2 (Target sexuality: lesbian, straight) x 4 (Stereotypes: Agency and Assertiveness, Agency and Competence, Communion and Morality, Communion and Warmth) repeated measures analysis of variance. These results yielded that for Black lesbians there are unique stereotypes that differ based on their intersectional identity, wherein race and sexual orientation both/and influence stereotyping, following the trend that when intersectional identities are stereotyped their stereotypes often oppose those applied to groups with one aspect of their identity.PsychologyBachelors of Science (BS
Nationalism in the Museum: Power and Discourse at the National Museum in Warsaw
No full textMuseums are spaces of power which have a profound impact on engaged visitor’s perception of a state, nation, or their own national identity. Thus, nationalistic narratives and discourse can be strategically utilized in museums (especially national museums, which operate as key diplomatic spaces) to present a singular, glorified, ‘national identity.’ This narrative is enforced for both domestic visitors and disseminated abroad as a form of ‘cultural diplomacy.’ Critical museology has continually sought means to diminish this intrinsic power and dismantle such dominant narratives; however, the extent to which museums have embraced and implemented this change varies widely. Anthony D. Smith’s ethno-symbolic nationalism, which emphasizes the role of historical context, collective myths, a physical homeland, and cultural production and elites in nation formation is a valuable framework to analyze such discourse. Cultural production within this framework predominantly serves a dominant ‘ethnie’. The Polish nation was largely consolidated through cultural production during the eighteenth century, while Poles lived in Russian, Austrian, and Prussian states. In the twenty-first century the far-right Law and Justice Government (Prawo i Sprawiedilwosc, or PiS) seized control of Polish national museums and cultural institutions which have endured censorship, deterioration, and the imposition of highly nationalistic rhetoric. This thesis examines the 2020 temporary exhibition ‘Poland. Power of Images,’ digitized by the National Museum in Warsaw, as a case study of such nationalistic rhetoric and discourse. The expansion of museums into the digital space has increased their reach, without decreasing their power. Key Words: Ethno-symbolism, nationalism, cultural diplomacy, museum, national museum, national identity, power, discourse, digital exhibitionInternational RelationsBachelors of Arts (BA
An Analysis of the Physical Properties of Diatom-Based Solutions for 3D Printing Applications
No full textDiatom-based solutions, composed of their silica cellular walls called frustules, hold significant promise in various applications, especially in 3D printing. Understanding the role of the physical properties that affect the end product is crucial for optimizing the production and performance of diatom-based silica structures. This thesis investigates how feed rate (i.e., how much the plunger moves per minute) and needle size affect peak stress (i.e., maximum stress at which liquid is extruded from the needle) and viscosity through a series of controlled experiments. Two different types of instruments were used: a rheometer and a tensile tester. Out of the variables examined, needle size has the greatest influence on peak stress and viscosity, whereas the impact of feed rate on peak stress and viscosity can vary depending on the needle size. Further exploration is needed for applications of diatom-based solutions in 3D printing to determine which feed rate is optimal for each needle size in order to print the best structure possible.PhysicsBachelors of Science (BS
Encountering Fungal Crossroads: How the Ambrosia Symbiosis Influences Wood Decay and Fungal Communities in Diverse Hardwood Trees
No full textTrees store the majority of living terrestrial biomass. When trees die, specialized wood-decaying fungi release the carbon stored in their wood. This release of organic carbon to atmospheric carbon dioxide impacts carbon cycles, nutrient cycles, and climate. However, the rate of wood decomposition depends on fungal competition and on which fungi colonize the deadwood first. Fungus farming beetles known as ambrosia beetles are among the first organisms to colonize dying trees. They bore into wood and inoculate it with a variety of fungal symbionts. Their fungal partners have been thought to increase tree decay, but recent research suggests they may actually slow decay by competing with wood-decaying fungi in the wood of conifers. I hypothesized that non-native fungi associated with recently introduced and hyperabundant non-native bark beetles suppress wood decay and compete with native fungi. I found that the majority of ambrosia beetles in Williamsburg, Virginia were non-native, and ambrosia beetles readily colonized all 4 tested hardwood tree species (American Beech [Fagus grandifolia], Red Maple [Acer rubrum], Bitternut Hickory [Carya cordiformis], and Southern Magnolia [Magnolia grandiflora]). My study utilizes Lindgren Funnel collections, a beetle exclosure experiment, and DNA metabarcoding to observe the ambrosia symbiosis and measure its impact on wood decomposition in hardwood tree species. I found that ambrosia beetles significantly increased fungal diversity in wood. However, contrary to my hypothesis and previous work in pine wood, hardwood logs exposed to ambrosia beetles experienced more mass loss than logs without ambrosia beetle exposure. My results show that the effects of introduced ambrosia beetles and their symbiotic fungi on carbon cycling in forest ecosystems is more complex than previously thought because the effect changes direction with forest type (i.e., conifer versus angiosperm). As more non-native symbioses invade, it is imperative that we understand under which conditions the ambrosia symbiosis enhances or reduces wood decay and the native ecosystem’s unexplored response.BiologyBachelors of Science (BS
Analog Design of an AI-Powered Synthesizer
No full textThis writing discusses the background, design, testing, and implementation of a fully analog audio signal processing chain. This chain consists of a 4-band equalizer, phaser, tremolo, clipper, and wah-wah, the order of which is permuatble by patch cabling. This chain is meant to serve as the post-processing for the \textit{Waveform.ai }project AI-powered synthesizer. Engineering and appropriate design for low-frequency oscillators and voltage-controlled resistors are discussed, as well as design of the above-mentioned processing effects. Lastly, the system-level integration of all circuits is explored. Analog signal processing was found to demonstrate exceptional capability accompanied by unique sonic characteristics which distiguish it from digital signal processing. Although many audio effects may be implemented practically in the analog domain, some others—especially time-based ones—are far more difficult and require specialized fabrication.PhysicsBachelors of Science (BS
Novel Concepts for Habitat Suitability of the Federally Threatened Plant Aeschynomene virginica
No full textThis project examined the habitat preferences of the threatened species Aeschynomene virginica (sensitive joint-vetch) and investigated whether sediment eroded out of a nearby stream channel receiving runoff from an upslope storm drain can create suitable habitat for this species. Data were collected on a population of Ae. virginica near Jamestown Settlement. Salinity, tidal patterns, soil composition, canopy cover, surrounding vegetation, herbivory, and elevation were examined, and the results were compared to existing literature and community data from a nearby reference marsh. Ae. virginica was found in soil with less organic matter and a greater proportion of sand compared to the surrounding marsh. It was also found in a slightly elevated portion of marsh, and vegetation data showed evidence of disturbance. Canopy and vegetation data were in agreement with existing research in demonstrating that Ae. virginica thrives in open areas with low competition. These results indicate that stormwater runoff can create habitat for this plant via sediment deposition and disturbance. This understanding may be useful when identifying suitable habitat for the plant in surveys and GIS mapping.BiologyBachelors of Science (BS
Spectacular: A New Musical
No full textNicolas Vernay is an aspiring playwright, commissioned by the King to direct a cast of blue-blooded players during the Royal Wedding celebrations at Versailles. Leonor is a Spanish princess, arranged to be married to the philandering French Dauphin, Louis. Despite barriers of class and questions of honor, these two unlikely friends turn the court of Versailles upside down in fabulous French fashion in this new musical inspired by the works of Corneille, Moliere, and Perrault.MusicBachelors of Arts (BA
Let’s Get This Straight: LGBTQIA+ Compulsory Heterosexuality and Individual Timing of Queer Self-Acknowledgement and Public-Disclosure Across Demographic Factors
No full textLimited empirical research exists on the concept of compulsory heterosexuality (comp het). This thesis explored the relationship between various demographic variables with age of acknowledgement and disclosure of a queer identity for a queer William & Mary (n = 52) and a Virginia community (n = 98) sample (N = 150), as well as the relationship between various demographic variables and several comp het-related constructs (social desirability, social support, heterosexism, internal homophobia, connection to LGBTQIA+ community, heteronormativity, prior LGBTQIA+ knowledge, and experienced risk) for an overall William & Mary (n = 136) and Virginia community (n = 106) sample (N = 242). Individuals socialized as women were expected to experience the comp het-related constructs more greatly and both realize and come out as their queer identity later in life than individuals socialized as men. Participants responded to an online survey inquiring about a range of demographic factors, sexual identity, and subsequent experiences, including both validated psychological measures and items created for this study. Regression analyses and ANOVA post hoc comparisons linked demographics with comp het-related experiences, as well as age of acknowledgement and disclosure of LGBTQIA+ identities. An exploratory factor analysis found that the various comp het-related measures included in this study formed four subfactors as they covaried to form the latent construct of comp het. Additional structural equation modeling revealed that the proposed theoretical models for demographics as predicting the latent variable of comp het were an overall poor fit. While the hypotheses about a latent comp het variable were not supported by the findings of this research, several significant results did emerge that help form a basis of knowledge about comp het, as studied through an empirical psychological lens.PsychologyBachelors of Science (BS
Expanding the Scope of Bioconjugations Using Non-Canonical Amino Acids
No full textProtein bioconjugates, or proteins that are covalently bound to other molecules, have applications in a wide variety of fields including drug delivery, diagnostic imaging, and materials. For many of these applications, bioconjugation techniques that afford site-specific, homogenous conjugates are desirable. The incorporation of non-canonical amino acids (ncAAs) into proteins can provide bioorthogonal reaction handles that can be exploited in the synthesis of such conjugates. To this end, this thesis seeks to exploit ncAAs in the development of novel reactions and/or reaction sequences to couple proteins to one or more reaction partners in a site-specific manner. The development of a novel reaction cascade that employs a single bromoalkyne ncAA in the synthesis of a site-specific multivalent conjugate is explored. Novel hydroamination and hydrochalcogenation bioconjugation reactions that exploit a variety of alkynyl functionalities to generate divalent and multivalent conjugates are also investigated.ChemistryBachelors of Science (BS