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Searching for TTVs in Young Transiting Systems
Get PDFThe discovery of young (<800 Myr) transiting planets has provided a new avenue to explore how planets form and evolve over their lifetimes. Mass measurements for these planets would be invaluable, but radial velocity surveys of young systems are often overwhelmed by stellar activity. Transit timing variations (TTVs) offer an alternative route to masses that are less impacted by signals from the host star. Here we search for TTVs in a sample of 41 young systems hosting 61 transiting planets using data from Kepler, K2, and TESS. We recover previously reported TTVs, including V1298 Tau, TOI-2076, and TOI-1227, and identify new TTVs in six systems, including the 40 Myr planet TOI-837 b. We show that these TTVs are not an artifact of spots or other challenges specific to young stars. Overall, 26% of young planets in our sample show TTVs, which is far higher than the analogous rate from Kepler on older systems. While the TTV signals detected here are sparsely sampled, our work provides a clear priority list for additional ground-based observations to full characterize the TTV and eventually measure the masses and eccentricities of these planets.Bachelor of Scienc
When Lightning Strikes Twice: Capital Punishment Disparities from Sentencing to Execution in the United States
Get PDFThis thesis examines disparate outcomes in death sentencing and executions in the United States in the post-Furman era based on legally irrelevant factors (primarily race and gender). By determining the conditional probability of execution for death-sentenced offenders, this thesis reveals how disparities shift from the sentencing stage to the execution stage. Using nationwide aggravated homicide data and a death sentence database consisting of all post-Furman death sentences complete with case outcome and victim information data, death sentence and execution rates based on offender demographics, victim demographics, and the combination of the two, were calculated. At the sentencing stage, the results indicate disproportionate death sentencing of offenders with white and female victims, particularly for Black offenders with these victim types. At the execution stage, these disparities are significantly mitigated and—at times—reversed. These results suggest that the evidentiary standard and level of aggravation needed to sentence Black offenders and offenders with white and/or female victims to death is lower than for white offenders and those with nonwhite victims. Ultimately, this thesis adds a new dimension to the understanding of disproportionality and discrimination in capital punishment in the United States.Bachelor of Art
Actors and Atrocity: The Impact of Actor Type on the Reported Prevalence of Sexual Violence in Armed Civil Conflict
Get PDFThis study aimed to examine how actor type influences the reported prevalence of conflict-related sexual violence (CRSV) in civil conflicts. Drawing on contemporary CRSV, civil war, and transnational feminist scholarship, I predicted that non-state actors would be associated with higher reported CRSV prevalence due to regimes of visibility that may obscure state violence while highlighting non-state violence. Using an ordered logistic regression model, this study assessed whether state and non-state actors have any statistically significant relationship to reported CRSV prevalence as reported by the SVAC dataset. The results indicate that state actors—especially incumbent states—are associated with higher reported prevalence compared to non-state actors. Additionally, cross-tabulations reveal that the disparity between state and non-state actors is substantially greater at prevalence level 1 compared to prevalence level 2. When further disaggregated by type, the study finds that supporting states rarely engage in CRSV in civil conflicts, and incumbent states and rebel groups are associated with higher levels of reported CRSV prevalence. This study suggests that regimes of visibility may not disproportionately obscure state CRSV relative to non-state CRSV. Further research is necessary to better understand how the visibility of CRSV impacts data collection, in addition to the potential differences in visibility, incentives, and capabilities between state and non-state actors relative to CRSV in civil conflict.Bachelor of Art
Castles in the Sky
Get PDFA collection of fantastical short stories that explores themes of love, grief, and self-discovery.Bachelor of Scienc
Evergreen
Get PDF"Evergreen" is a collection of essays that explores themes of love, loss, and memory, mainly through personal anecdotes and the lens of the natural world. Bachelor of Art
Quantification of Matrix Metalloproteinases via Multiplex Suspension Arrays for Aortic Aneurysm Detection
Get PDFAortic aneurysm disease is characterized by the weakening of the aortic wall, leading to a bulge in the aorta known as an aneurysm. Matrix metalloproteinases (MMPs) play a key role in maintaining the aortic extracellular matrix (ECM) through remodeling and can be detected in the bloodstream near the aneurysm. While immunoassays are well-suited for detecting enzymes such as proteinases, measuring multiple MMPs in plasma requires a highly sensitive and selective multiplex assay. Traditionally, singleplex enzyme-linked immunosorbent assays (ELISA) provided high sensitivity and selectivity for detecting a single biomarker per run based on enzymatic activity. However, ELISA cannot analyze multiple biomarkers simultaneously. Recent advancements in immunoassay technology, such as multiplex suspension arrays (MSAs), enable the simultaneous quantification of multiple proteinases across multiple samples in a 96-well plate. MSAs, such as Luminex xMAP technology, use color-coded magnetic microspheres conjugated with fluorescent antibodies. These microspheres are mixed with plasma samples, followed by the addition of a detection antibody to form a sandwich complex. The microspheres are then analyzed via flow cytometry, with fluorescence intensity used to quantify the target biomarkers. In an analysis of six human plasma samples for MMP-1, -2, -3, -7, -8, -9, -12, and -13, MMP-1, -2, -3, -8, and -9 were quantifiable, whereas MMP-7, -12, and -13 were undetectable. These findings suggest that bead-based MSAs are effective for quantifying specific MMPs and may contribute to improved diagnostics for aortic aneurysm disease.Bachelor of Art
Global Convergence of Block-Coordinate BFGS Method on Convex Non-smooth Problems
Get PDFThis thesis introduces a Block‑Coordinate BFGS (BC‑BFGS) method for convex composite problems F(x)=f(x)+g(x) with a smooth strongly‑convex f and non‑smooth regulariser g. Updating one variable block at a time with a Wolfe line search and block‑diagonal BFGS, the algorithm keeps per‑step cost low while preserving curvature information.
We prove global convergence: (i) by extending the Byrd‑Nocedal‑Yuan trace–determinant argument to block updates for the smooth case, and (ii) by applying local C2 convex extensions à la Lewis–Overton for non‑smooth settings, guaranteeing convergence to the unique minimiser.
Experiments confirm efficiency. On simulated Group LASSO data BC‑BFGS matches full BFGS accuracy yet is 10–100 × faster, and outperforms FoGLASSO and Inexact Proximal Gradient. On six LIBSVM logistic‑loss datasets it achieves similar or better loss with competitive runtimes. Varying block counts reveals an optimal partition that minimises both error and wall‑time, underscoring scalability. Thus BC‑BFGS extends quasi‑Newton strengths to large non‑smooth problems.Bachelor of Scienc
The Ends of Loving Relationships and the Union View of Love
Get PDFThe loss of love is more than just a lack of love. Losing a loving relationship is not merely unpleasant or inconvenient but profoundly disorienting. A good account of love should not only be able to clearly delineate between love and its absence but also offer a robust account of the transition from one state to the other. I survey prominent accounts of love, analyzing how they might account for the ends of loving relationships. I argue that the ends of loving relationships presents a problem for each of these views of love, demanding more or less severe revisions, but I also argue that the union view of love—given its emphasis on the way in which love transforms a lover—is in the best position to address this novel problem. Bachelor of Art
Scaling up the Med-South Lifestyle Program in public health settings to reduce chronic disease risk: a hybrid implementation-effectiveness study
Get PDFMajor disparities persist in heart disease, diabetes, and obesity, with rates highest among those living in the southeastern and central parts of the US. Intervening to improve lifestyle behaviors represents an opportunity to address health inequities. Although the scientific rationale for lifestyle interventions is robust, evidence is limited on how to implement these interventions at scale. Using a type 3 hybrid implementation-effectiveness design, we evaluated a statewide scale-up trial implementing the Med-South Lifestyle Program in mostly rural community health centers and health departments across North Carolina, in the southeastern US. Implementation outcomes were measured at the site level and program effectiveness outcomes were assessed by physiologic and behavioral changes at the participant level. Descriptive statistics and paired t-tests comprised our statistical analyses. We invited 200 public health sites to participate in the study and 28 (14%) expressed interest. Among those expressing interest, 21 (75%) signed a Memorandum of Agreement. The statewide scale-up resulted in the enrollment of 95% (19/20) of the proposed sites−13 health departments (68%) and six community health centers. The majority of the 235 study participants who started the program were adults self-identifying as non-Hispanic White (45%) or non-Hispanic Black (37%); 11% identified as Hispanic and 5% as American Indian. Most participants were female (88%), with a mean age of 51 years, and educational attainment of a 2- or 4-year college degree (57%). Implementation outcomes included 17 sites (89%) retained throughout the study and a 79% participant retention rate. Program uptake was high, with 87% of planned counseling sessions and 83% of follow-up calls completed. For our effectiveness outcomes we observed small but statistically significant changes in weight of −2.3 lbs. Similarly, systolic but not diastolic blood pressure was reduced significantly (−2.3 mm Hg). There was a significant increase in the mean weekly intakes of nuts and healthy fats, improved daily fruit-vegetable-bean scores, and a decrease in daily sugar-sweetened beverage intake. For sedentary behaviors, daily sitting time was significantly reduced. These results show successfully adapted implementation and delivery approaches to fit Med-South into the context of public health settings during the COVID-19 pandemic. ClinicalTrials.gov: NCT05067816, October 5, 2021
Itaconate and obesity-related hormones promote tumor progression – new insights on metabolic dysfunction in early-onset colon cancer
Get PDFObesity is a strong risk factor for early-onset colon cancer (EOCC) and is associated with chronic inflammation largely mediated by macrophages. The macrophage-specific metabolite itaconate promotes growth in several types of cancer; however, its role in colon cancer (CC) is unknown. Here, we investigate a tumor promoting link between obesity-related hormones and itaconate within the NOTCH4-GATA4-IRG1 pathway in EOCC. Patient tissue (n=20) was obtained and qRT-PCR, ELISA, and mass spectrometry were performed to evaluate IRG1 expression (Human Immune-Responsive Gene 1, encoding ACOD1), ACOD1 expression (Cis-aconitate decarboxylase 1, enzyme producing itaconate), and itaconate concentration in human CC versus EOCC. RNA sequencing data from 5 sources in the USA and Europe were obtained to perform IRG1-related differential expression analysis (n=178), IRG1-related survival analysis (n=185), and differential expression analysis and survival analysis related to genes of the NOTCH4-GATA4-IRG1 pathway (n=371). Furthermore, tumor versus normal colon was compared and the interaction of tissue with sex, age, and body mass index (BMI) was investigated. A coculture model using two CC cell lines (HT-29 and SW480) and THP-1 cell line-derived M0 and M2-like macrophages was used to evaluate NOTCH4-GATA4-IRG1 pathway-related gene expression following treatment with obesity-related hormones (leptin, adiponectin) and itaconate derivatives. Both ACOD1 and IRG1 expression were elevated in human CC tissue compared to adjacent normal colon tissue. Normal colon itaconate levels were higher in EOCC patients compared to that in older patients. Plasma itaconate levels in CC patients correlated with their BMI. Survival was decreased in IRG1-positive stage IV CC. IRG1-associated gene expression within the NOTCH4-GATA4-IRG1 pathway differed in CC versus normal colon tissue: GATA4, DLL4, VEGFA, and MAPK15 upregulation was associated with EOCC, while ABCG5 and GATA5 were downregulated in CCs and associated with higher BMI. Adiponectin and leptin treatment of macrophages cocultured with CC cells increased IRG1 expression. Obesity-related hormones can increase itaconate production in M2-like macrophages. IRG1 expression and the NOTCH4-GATA4-IRG1 pathway are associated with EOCC, BMI, and patient survival. As a macrophage metabolite affecting inflammation, itaconate may have a particular immunotherapeutic role in patients with EOCC