Lizards in the family Tropiduridae have ventral epidermal gland organs that are involved in chemical signaling and whose secretory mechanism is entirely unknown. This is because, like other epidermal generation glands, 'alpha-glands' lack a pore through which their secretion can be exerted. Chemical signaling is a valuable aspect of tropidurid lizards' social and ecological interactions, and some have been observed territorially scraping their alpha-glands against the substrate. This process has been hypothesized to facilitate the release of chemical signals via abrasion. To investigate this abrasion hypothesis, we analyzed 74 skin samples from 27 tropidurid species, using light microscopy and scanning electron microscopy (SEM). The SEM revealed incredible surface variability in epidermal glands, providing morphological insight. We found that the exposed glandular mass of each gland scale rests atop the oberhautchen layer of the skin's subjacent generation, which indicates that the secretion of chemicals involves exposing a mostly solid glandular material on the outside of the scales. Histological sectioning of gland scales revealed morphological consistency, indicating that the same secretory mechanism is shared across the tropidurid phylogeny. Imaging of histology samples also revealed that the shedding process which exposes the glandular material may be facilitated by the clear layer, found directly above the glandular mass during development. Characterization of morphological patterns in the formatted SEM images and comparison with histological data should provide evidence for or against taxon-specific or ecology-specific alpha-gland structures, and further support the idea of chemical secretion requiring epidermal exposal of glandular material. Investigations of the morphology and functional mechanism of this unique organ provide insight into the behavior and evolution of tropidurid lizards and shed light on factors influencing the evolution of chemical signaling in terrestrial organisms. 

Chemical communication is the oldest and most widespread form of communication across the tree of life, and markedly present among lizards. However, the drivers of chemical profile variations in this group remain for the most part uninvestigated. In South American lizards of the Tropiduridae family, semiochemicals are produced by epidermal gland organs called α-glands, exclusively found on the ventral side of male individuals of at least 40 species from four genera. The chemicals produced by these glands are hypothesized to interact with their environments in different ways since chemical species are naturally reactive and tend towards their lowest energetic state. Thus, the intrinsic properties of a semiochemical impact its survival and efficacy for communication. Given the diverse ecology and broad geographical distribution of tropidurids, we investigated whether variation in the chemical composition of α-gland secretions correlates with temperature, humidity, and habitat openness. We performed liquid chromatography-mass spectrometry (LCMS) to obtain the metabolomes of three different sample types. We sampled male skin containing the α-glands, undifferentiated male skin, and female skin. Environmental and chemical property data were extracted from online databases, literature, and field observations. Preliminary tests were done by making Venn diagrams comparing the metabolomes of each sample type. These revealed differences in metabolite compositions, notably between males and females as well as between glandular and undifferentiated skin. From the metabolomes of α-glands, we expect to see chemical species with properties that confer greater survival given the specificities of the environment. For example, given a lizard from a hot and humid environment, we expect the metabolome of the α-glands to contain higher molecular weight species with less functional group complexity. Understanding how environmental parameters drive the chemical composition of α-glands is expected to provide a deeper understanding of the evolutionary history of chemical signaling in terrestrial vertebrates.

Rhabdomyosarcoma (RMS) is a devastating soft tissue sarcoma most commonly affecting children. The components in the RAS-PI3K-MAPK signaling pathway are frequently mutated in RMS and are being studied as a critical target for treatment. A MEK1/2 inhibitor, trametinib, has shown clinical efficacy singly or in combination with other drugs in improving survival outcomes of patients with cancer types harboring mutations in the MAPK pathway. In addition, vincristine is a common chemotherapeutic drug used to treat RMS, but its efficacy has been limited due to RMS cells developing resistance. The study aims to determine whether combined treatment of vincristine and trametinib could more significantly inhibit RMS cancer growth compared to treatment with each drug alone. For this study, a clonal zebrafish line bearing RMS tumors labeled with a fluorescent protein was first treated with a range of trametinib concentrations to find the appropriate dosage for optimal effectivity yet minimal toxicity. Then, RMS-bearing zebrafish received two doses of trametinib, vincristine, or a combination of both through intraperitoneal injections (IP). Finally, we collected tumors from each treatment group to assess treatment-induced changes in gene expression by quantitative RT-PCR and changes in tumor cell proliferation and cell death by immunohistochemical stains. The changes in tumor volumes were determined by quantifying the intensity of tumor fluorescence in the ImageJ software. Preliminary findings showed that zebrafish tumors treated with the combination of vincristine and trametinib significantly inhibited tumor growth compared to the other with each agent alone. Thus, the results of this in vivo study on zebrafish may introduce a drug dosage combination with translational potential in creating a new treatment composed of lower doses of each drug while increasing potency against chemotherapy-resistant tumors and lessening side effects in patients. The end results will translate into improved survival outcomes and well-being of RMS patients.

The UN Truth Commission tasked with accounting for El Salvador’s armed conflict described it as a war in which “nobody won” (“nadie ganaba”). Between 1980 and 1992, the small Central American country was devastated by a civil war that claimed the lives of more than 70,000 and exposed its people to gross human rights violations committed, overwhelmingly, at the hands of state security forces. This project asks how the armed conflict in El Salvador existed within a broader ecosystem of right-wing state terror by examining one particularly crucial relationship: that between El Salvador and Argentina in the period immediately before the outbreak of war (1978-1980). I argue that the military regimes in El Salvador and Argentina took on a consultatory relationship during the late 1970s in which Argentina passed its “successful” model of repression onto key Salvadoran military officials. As El Salvador barreled toward war in late 1979 and early 1980, those very same Salvadoran officials came to occupy the highest positions of power, paving the way for an urban war campaign that looked eerily like Argentina’s “dirty war.” By pairing archival research conducted at the Historical Archive of the Chancellery (Archivo Histórico de la Cancillería) in Buenos Aires with existing scholarship on Argentine involvement in Central America, I trace the rise of Argentine influence in El Salvador from a few well-placed offers of aid to the minds of four of El Salvador’s top-ranking wartime officials. In doing so, I look beyond the Cold War in Latin America as a phenomenon imposed from above by the United States and instead interrogate the middle layer, in which Latin American states, driven by politics, culture, and their own will to survive, reproduced the Cold War along more local and regional lines.

 The 1854 Speech by Chief siaʔɬ (Seattle) is surrounded by controversy. There are many versions of this speech available online and in print, but which one is the most true to who Chief siaʔɬ was? How can we find out what Chief siaʔɬ said when the speech was given in Lushootseed, translated to Chinook Jargon, and then published for the first time in English, 30 years after the speech was given? Today, even Chief siaʔɬ's tribal descendants have differing versions of the speech on their official tribal websites. To answer these questions, I conducted semi-structured individual interviews with tribal members from each of Chief siaʔɬ's descendant tribes, the Duwamish, the Suquamish, and the Muckleshoot. Within these interviews, I chose to use the "Think Aloud" method to structure how the participants read the versions of the speech presented. This allowed me to code their comments on the speech into specific categories in order to analyze how each participants felt about the speech, about Chief siaʔɬ's character, and about their own knowledge and their tribe's own knowledge about the speech and speaker. This research provides a brand new and comprehensive perspective on this aged speech that is surrounded by mystery. It gives these tribal members the opportunity to set the record straight on what Chief siaʔɬ might have actually said.

To perform its function as a tumor suppressor, breast cancer 1 (BRCA1) must dimerize with BRCA1-associated RING domain protein 1 (BARD1). Due to this critical interaction, pathogenic BARD1 variants are also associated with increased breast and ovarian cancer risk. Genetic testing has identified many rare single-nucleotide variants (SNVs) that cause missense amino acid substitutions in BARD1. Currently, 93% (1,692 of 1,819) of BARD1 missense SNVs are classified as a variant of uncertain significance (VUS) in ClinVar. A VUS classification prevents clinicians from using genetic test results to guide patient care. Consequently, there is a strong need to functionally assess BARD1 SNVs to help resolve VUS. We applied a multiplex assay for variant effect called saturation genome editing (SGE) to functionally assess all possible 12,000 SNVs and 2,300 3-base deletions in BARD1. In SGE, we use CRISPR-Cas9 to edit all possible SNVs into a region of BARD1 in haploid HAP1 cells. BARD1 is essential for cell growth, therefore cells edited with loss-of-function variants become depleted from the population. We track which SNVs become depleted from the population by sequencing. We then generate functional scores for each variant by calculating the change in the abundance of a variant in the original SNV library versus its abundance in the cell population after 13 days in culture. Thus far, I have generated reagents for all 14,300 variants and 2,400 have completed the full experimental pipeline. Functional scores for the functionally critical BRCA1 interaction domain show depletion of 94% stop-gain, 48% splice-site, and 21% missense variants relative to 5% synonymous and 6% intronic variants. This ultimately demonstrates SGE’s ability to accurately identify functionally normal and loss-of-function BARD1 variants. Generating functional scores for all possible BARD1 variants will provide the functional evidence needed for reclassifying BARD1 VUS and definitive test results for providers treating patients with BARD1 variants.

At 1:44 PM EST on March 11th of 2020, Trump tweeted that he would be “addressing the nation” at 9 PM EST that same day. This oval office address was a statement on COVID-19 and what the pandemic meant for America. This research is a rhetorical analysis of Trump’s public address on that day. His speech, already given in a time of uncertainty, led to widespread panic amongst consumers, with U.S. stocks falling the next day by almost 10%, in their worst day since the 1987 crash. News outlets and economists reported that the uncertainty that came along with the pandemic was only worsened because of Trump’s fear stoking and the atmosphere of uncertainty this speech created. What were people reading in the speech that could have pushed them towards this economic behavior? Conducting a rhetorical analysis of the speech through an innovation on the textual-intertextual method, this paper analyzes Trump’s speech and what people and the Trump administration said in response. In the first part of the paper, close textual analysis allows us to have an in-depth, microscopic understanding of the speech itself. In the second part of the thesis, we examine intertextual evidence of the speech’s extrinsic effect. Reading secondary sources that explicitly mention the primary text, including those produced by audiences hailed by the text as well as by Trump and his proxies, we can understand its broader reception especially as it relates to investor behavior and consumer attitudes. This study finds that Trump’s lack of key information, sparse emphasis on international cooperation, and contradictory rhetoric towards public officials all help explain the economic uncertainty that resulted from this speech. Studying the relationship between rhetoric and the economy through this research has implications on presidential rhetoric, unsuccessful early pandemic communication and the factors influencing stock price volatility.