Sample Expo Abstracts
dpNSOM: A Novel Nanoscale Refractive Index Measurement Technique
To diagnose and treat cancers at an early stage, research focuses on early detection using imaging as well as techniques to characterize cells, structures, and molecules. Optical microscopy is a widely used technique to analyze cell structure. However, the resolution of conventional optical microscopy is diffraction-limited. This poses a roadblock to detecting cancer at an early stage, as studies have indicated that nanoarchitectural changes, significantly smaller than the diffraction limit, precede histologically noticeable events such as dysplasia. These changes are invisible to optical microscopy techniques that are currently considered the gold-standard. My research is aimed at demolishing this roadblock. I am using a near-field scanning optical microscope, NSOM, to develop a novel means to quantify optical refractive indices within biological cells. Probing in the depth direction, depth probing NSOM, dpNSOM, has a resolution of 50 nm or finer, fully one order-of-magnitude below the diffraction limit. The techniques that I am developing could be used to analyze cells that are potentially in the earliest stages of cancer. From the basic-science perspective, the data obtained in this manner would serve to increase basic knowledge of fundamental nanoarchitectural changes in a cell that accompany cancer progression. From the public health perspective, the techniques I am developing would potentially facilitate a robust and life saving cancer screening methodology.
Partial Urinary Bladder Regeneration Utilizing Mesenchymal Stem Cells Seeded onto an Elastomeric Thin Film
The need for a novel bladder augmentation model is long overdue. Patients with dysfunctional neurogenic bladders, such as those with spina bifida, undergo extensive surgery to augment the bladder in order to increase the capacity to hold urine. Yet this surgical intervention does not improve bladder function as urodynamics of the augmented bladder remain unchanged. This study takes advantage of the plasticity of bone marrow derived stem cells and the elasticity of recently developed biomaterials towards bladder regeneration efforts. Mesenchymal stem cells (MSCs), endothelial progenitor cells (EPCs) and poly(1,8-octanediol-co-citrate) thin films (POCfs) were evaluated. MSCs demonstrated a high viability and proliferation capacity in vitro and when cultured on POCfs, and even expressed contractile proteins in an undifferentiated state akin to bladder smooth muscle cells (SMCs). To replicate the bladder augmentation surgery, MSCs seeded onto POCfs were implanted into a nude rat bladder, resulting in robust MSCs growthin vivo. MSCs post-implantation had an enhanced contractile protein expression as well. This protein profile allowed for carbachol-induced in vitro contraction, clearly confirming MSC candidacy in bladder smooth muscle regeneration. EPCs, when cultured in a CAM model, developed branched vasculature. Additionally, ureteral SMCs (spared of neurogenic pathology) had a high proliferation capacity and expressed contractile proteins found in SMCs as well. These findings suggest that POCfs cradle the growth of MSCs and EPCs, developing into the smooth muscle and vascular network of the bladder wall, respectively. This novel approach to bladder reconstruction may contribute towards eradicating the need for self-catheterization and improving bladder functionality in spina bifida patients.
Bioavailability of Mercury in Aquatic Systems
Inorganic mercury is released directly and indirectly to the environments as part of several industrial processes such as coal burning. In the natural environment, anaerobic organisms in aquatic systems transform the inorganic mercury to methylmercury through a process called methylation. Methylmercury is a toxin that bioaccumulates in the aquatic food chain, with high concentrations found in many species of fish that humans consume. Ingested methylmercury is readily and completely absorbed by the gastrointestinal tract and transported across the blood-brain barrier and the placenta. Therefore, from both and environmental and public health perspective, this organometallic compound has become an alarming pollutant. In order for methylation to occur, inorganic mercury must first be bioavailable—able to enter a cell by passing through the cell membrane. Our research investigates how the bioavailability of mercury changes in the presence of various anthropogenic ligands and natural complexants, including ethylenediaminetetraacetic acid, nitrilotriacetic acid, cysteine, humic acid, and citrate. Bioavailability was measured via bioluminescence assays performed on a genetically engineered whole cell mercury bioreporter (Escherichia.Coli ARL1 with merR::luxCDABE fusion). Our results show that cellular mercury uptake is greatly enhanced in the presence of the amino acid cysteine (10-2 µM – 10-4 µM levels), suggesting that a mercury-cysteine complex forms to facilitate the cross-membrane transfer. Meanwhile, mercury uptake is greatly inhibited in the presence of citrate (10-2 µM levels). Therefore, because the bioavailability of mercury changes by complexing to ligands, microbial methylations of mercury will strongly depend on the composition and quality of an aquatic system.
The Bearded Woman on the Cross: St. Ontcommer and Medieval Popular Piety
According to legend, St. Ontcommer was a young princess of Portugal who renounced paganism and refused to marry. When God sent her a full beard to help her escape a suitor, her own father had her crucified in anger. In northern Europe during the late Middle Ages, versions of this legend circulated widely and hundreds of works of devotional art were dedicated to the androgynous virgin saint. In over five centuries since her legend first emerged, the bearded woman on the cross has been recognized as the patron saint of prisoners, the sick and dying, soldiers, fertility, childbirth, livestock, musicians, bakers, travelers, marriage, incest survivors, and women seeking escape from bad relationships. This paper investigates the emergence of the cult of St. Ontcommer, seeking to explain the significance of this seemingly unusual popular figure within her own late-medieval context. I use art and textual evidence to show that the cult of St. Ontcommer became widespread in part because she encompassed both an ideal of bodily women’s spirituality and a tendency towards the feminization of Christ important to art and literature of the later Middle Ages. Additionally, her ambiguous representation suggests multiple possibilities for access to the divine, allowing her to serve as an adaptable and powerful symbol to her diverse supplicants. Finally, her transgression of boundaries between male and female, “disfigured” and transcendent, reflects both the fluidity and the paradox important to late medieval conceptions of gender and the body, particularly as they apply to perceptions of the holy.
Space Invaders: Street Art, Site-specificity, and the Contest for Urban Space
Street artists appropriate urban space for aesthetic interventions, acts that imply opposition to the prescribed structures and pathways of the city. Analyzing the works of Vhils and Banksy, two prominent street artists who practice in London, I examine the ways in which street art engages the city as a site of critical inquiry, a space to be celebrated and interrogated, fought for and fought. In making artworks that critique the city from within its streets, these artists make visible hidden aspects of the urban condition: the economic and political forces that shape urban space and prescribe its uses; the populations of city dwellers who are subjected to the structuring of urban space and the everyday experience of urban living; and the possibility of alternative uses of urban space—the ways in which spatial structures and strictures can be subverted by urban spatial interventions. Informed by field research and building upon urban spatial theory and models of site-specific art making, I argue that the visual interventions of street art encourage a rethinking of urban space by those who occupy it but have little influence over its production. Making art that confronts the forces of urban spatial structuring in the space of the city, these artists not only expose the city to the mechanisms of its own contentious production, but site it as ground zero of the contest over the control of urban space.
Mirrored Malinches: Gender and Geopolitics in Lone Star and Their Dogs Came with Them
La Malinche became the Indian translator for Hernán Cortés and the Spanish Conquistadors after they arrived in Mexico in the early sixteenth century. Because of her role as both translator for the Spanish and as Cortés’s concubine, La Malinche has traditionally been considered a traitorous figure in Mexican and Chicano/a culture. Chicana feminists have attempted since the 1970s to redeem the figure of La Malinche by framing her as a symbol of female agency oppressed by Chicano nationalist patriarchy. My thesis analyzes two fictional works – the film Lone Star by John Sayles and the novel Their Dogs Came with Themby Helena María Viramontes. Both works use doubled representations of La Malinche to reflect the pervasive misogyny of Chicano nationalism and broader American society. I argue that that these two works situate discussions of gender within a broader geopolitical context that is often ignored by Chicana authors referring to La Malinche. As a woman who translated between languages and symbolically blended the races of indigenous Amerindians and Europeans by bearing Cortés’s child, La Malinche crossed ethnic and political borders. The unstable identity boundaries which these works depicts between the doubled Malinche figures function as a metaphor for other permeable boundaries, such as those between Mexico and the United States and between racially segregated communities in the United States. By analyzing how both works use La Malinche to critique traditional understandings of both gender and geopolitics, I aim to contribute to an emancipatory politics of literary interpretation that simultaneously addresses gender oppression and divisions between racial, ethnic, and national groups.
The Effects of Chinese Commercial Investment on Governance in African States
Chinese economic engagement with African states has expanded rapidly throughout the past decade via trade, foreign direct investment, loans, and direct development financing. This project explores theories of governance in modern Africa and investigates the effects of Chinese commercial investment on governance in African states. I use the cases of Angola and Ethiopia in order to evaluate how regime type, degree of institutionalization, sector of investment, and financial mechanisms associated with Chinese projects affect African governance. Even if the types of financing options employed by China create growth or align with positive development indicators, there are still effects on governance that may cause a perpetuation of the same economic problems financing aims to fix. My research indicates that instead of shrinking the African state, increasing Chinese commercial investment has the effect of reinforcing executive authority and patrimonial structures of governance that allow the state to thrive off the co-option of the private sphere. In a region where presidential power is increasingly consolidated by strong executives, Chinese investment may be supporting elements of informal governance which allow the perpetuation of patrimonial tendencies and political patronage networks.
The Scientific Gender Gap: Gender Bias in Facial Inferences that Predict Scientific Influence
Although the number of female scientists earning graduate degrees in science, technology, engineering and math (STEM) fields has increased steadily in the past 15 years, the gender gap in higher echelons of science has remained. What psychological factors underlie the scientific gender gap at the highest levels of STEM fields? From politics to business, facial appearance has been shown to play a pivotal role in predicting an individual’s success. In this study we examined the possibility that facial appearance may contribute to scientific success and, in particular, to a gender gap in scientific influence as measured by h index. Sixty Caucasian American undergraduate students viewed 110 grayscale facial photographs (55 females) of professors at the top five STEM departments. Participants viewed each face for a brief moment and rated how approachable, attractive, competent, and dominant the face seemed on a 7-point scale. Across all faces, scientific age (year of PhD) was a positive predictor of h index. For female scientists, perceived approachability and dominance of facial appearance were negative predictors of h index, whereas for male scientists, facial inferences did not predict scientific influence—there were no significant predictors of facial appearance in predicting h index for men. The follow-up study revealed that the significant predictors of scientific influence for female professors observed in the initial study were unique to the scientists at the top five institutions. These results indicate that shallow decision heuristics, such as trait inferences made from the face, play an important role in scientific influence and may contribute to the perseverance of gender gap at the highest levels of STEM fields.
Living in Between: How Rural to Rural Migrants Navigate Transnational Lives
Previous literature on transnational migration has studied migrants moving to urban centers in the United States. This study looks at a population we’ve missed: those who travel to rural receiving regions. The major forces that previous researchers have argued maintain transnational contact are political, religious and social organizations that are all but nonexistent for the migrants arriving in rural regions. This study explores the nuances of transnational life when it is anchored in rural areas of both the sending and receiving countries. Findings are based on a qualitative study of five immigrant families living in rural Western New York and their relatives in San Juan Mixtepec, a small indigenous community in Oaxaca, Mexico. The nature of rural life means people are isolated. No hometown organization helps Mixtepec migrants maintain contact with each other or anyone back home, and Oaxacan politicians do not worry about reaching out to a Western New York contingent of citizens. Furthermore, there are few options for religious involvement in Spanish and no opportunities to worship in Mixteco. Yet these immigrants still live transnational lives, maintaining ties to their home and culture through personal agency, not institutional support. Findings in this study fill a hole in our knowledge of transnational migration by focusing on rural to rural migrants. A revision of theory is necessary with a focus on non-institutional maintenance of transnational ties to fully understand the lived experience of these migrants, a population that comprises almost the entirety of the foreign farmworker population.
*adapted from Northwestern University