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To See and Be Seen: Factors Influencing the Retention of Black Teachers
Get PDFThis phenomenological research study explores the factors influencing the retention of Black teachers in a large urban school district in the post-COVID-19 era. Black teachers play a critical role in improving educational outcomes, yet their retention remains a persistent challenge exacerbated by pandemic-related stressors. Through focus groups and individual interviews, this research centers the lived experiences of Black teachers to explore their motivations for remaining in the profession, despite enduring systemic and interpersonal racism, inadequate pay, and burnout. Findings reveal that Black teachers are driven by a profound sense of responsibility towards Black students, striving to provide representation and to embody visibility—to see and to be seen. Grounded in Critical Race Theory, this study highlights how systemic racism intersects with generational wealth and professional identity to shape retention decisions. The findings call for targeted initiatives that leverage the perspectives of Black teachers to build a diverse and resilient workforce.Doctor of Educatio
Invariance of Gibbs Measures on the Phase Space of the Periodic Ablowitz-Ladik System
Get PDFIn this paper, we analyze the dynamics of the periodic defocusing Ablowitz-Ladik system, a discretization of the nonlinear Schrödinger equation. In particular, we investigate the conservation laws and invariance properties of Gibbs measures for the AL system by leveraging its Hamiltonian structure and integrability. We first establish the existence of a maximal family of conservation laws which underpin its dynamics. Building on these conservation laws, we construct Gibbs measures associated with the AL system through statistical ensembles weighted by its conserved energies. Utilizing techniques from integrable systems theory and symplectic geometry, we prove that these measures remain invariant under the AL flow, thereby bridging the dynamics of the discrete system with its statistical equilibrium properties.Master of Scienc
Strategic Signaling: How Members of Congress Emphasize or Obfuscate Bipartisan Behavior
Get PDFMembers of Congress engage in bipartisan behavior to varying degrees, yet their public messaging does not always align with their actions. This study examines why legislators strategically emphasize or obfuscate their bipartisan behavior when communicating with constituents. Using a new measure of bipartisan coalition-building based on original cosponsorship and a dataset of congressional e-newsletters analyzed with OpenAI’s embeddings model, I develop a misalignment score that captures the extent to which members misrepresent their bipartisan legislative work. My findings reveal that party is crucial: Democrats tend to overstate their bipartisanship in messaging, while Republicans systematically downplay their bipartisan activities. Additionally, institutional differences matter. Senators are more likely than House members to exaggerate their bipartisan behavior. These results highlight the strategic nature of congressional communication and suggest that legislators tailor their messaging to partisan expectations rather than accurately reflecting their legislative behavior.Master of Art
EFFECTS OF MEMBRANE PROPERTIES ON THE LOCALIZATION AND ASSEMBLY OF THE SEPTIN CYTOSKELETON
Get PDFThe septin cytoskeleton comprises a well-conserved class of membrane binding proteins critical for organizing major changes to cell shape. Septins do this by assembling into filament arrays, often at sites of membrane curvature, to organize cell signaling factors. In vitro, septins display a narrow preference for 1 µm diameter membrane curvatures, similarly to their most common binding sites in cells. Like many other curvature sensing proteins, septins possess an amphipathic helix that, in the case of septins, is necessary and sufficient for localization to their preferred curvature both in vitro and in cells. However, septins can assemble on an array of membrane geometries, suggesting additional cues for their localization. This work describes the impact of membrane properties, specifically the property of lipid packing dictated by both membrane curvature and lipid composition, on the localization and assembly of the septin cytoskeleton. Here, we designed lipid mixtures varying in lipid packing by molecular dynamics simulations and incorporated these compositions onto supported lipid bilayers to measure septin adsorption in vitro. Septins strongly favor loosely packed, disordered lipid bilayers but additional geometry cues act in conjunction with this membrane property. Introducing tighter lipid packing in cells disrupted septin structures in a curvature dependent manner, specifically limiting septin assembly and retention along flat regions of the plasma membrane. This work demonstrates that packing defects and geometry jointly regulate septin localization and highlights how multiple membrane properties are integrated to control organization of the septin cytoskeleton.Doctor of Philosoph
Examining the Role of Socioeconomic Adversity on Depressive Symptoms during Pregnancy among Non-Hispanic Black Women
Get PDFThere is an increasing need for mental health care among the greater population of the United States, a need which is patterned by preexisting social, demographic and economic injustices. The experience of depressive episodes occurring over the course of pregnancy follows these patterns, and yet remains an understudied area of research. Despite this, the experience of depression is estimated to affect at least between 10 % and 20 % of pregnant people in the United States, with higher estimates for people of color and those living in poverty (Le Strat et al., 2011; Mukherjee et al., 2016; Van Niel and Payne, 2020). Depression represents a collection of symptoms, including hopelessness, despair, empty moods, irritation, lack of concentration, loss of appetite, sleep disturbances, and suicidal ideation (Jahan et al., 2021). These symptoms often lead to a negative impact on an individual’s ability to perform day-to-day activities and functions. Symptoms common with depression, such as sleep and energy disturbances, may be attributed to pregnancy alone, leading to underdiagnosis during this part of the life course (Marcus, 2009). For birthing parents, prenatal depression has been associated with inadequate weight gain, under-utilization of prenatal care, and increased substance use (Marcus, 2009). There is additional evidence that depression during pregnancy increases the risk for the child, with its association to preterm birth, growth restriction, and low head circumference (Ghimire et al., 2021; Li et al., 2020; Marcus, 2009; Van Niel and Payne, 2020). Untreated depression may also increase the risk of impaired social, cognitive, and emotional development of the child (Van Niel and Payne, 2020). Studying depressive symptoms during pregnancy is crucial for the well-being of the birthing parents, particularly among marginalized groups facing multiple, intersecting structural barriers to care (Goodman, 2020; Gotlib et al., 2020; Martin et al., 2024)
[NOPN] Behind the Numbers: Making Sense of Trends in the Drug Supply and Overdose Rates
No full textPresentation on the current drug supply to the National Overdose Prevention Networ
High-dimensional Biomarker Identification for Interpretable Disease Prediction via Machine Learning Models
Get PDFMOTIVATION: Omics features, often measured by high-throughput technologies, combined with clinical features, significantly impact the understanding of many complex human diseases. Integrating key omics biomarkers with clinical risk factors is essential for elucidating disease mechanisms, advancing early diagnosis, and enhancing precision medicine. However, the high dimensionality and intricate associations between disease outcomes and omics profiles present substantial analytical challenges. RESULTS: We propose a High-dimensional Feature Importance Test (HiFIT) framework to address these challenges. Specifically, we develop an ensemble data-driven biomarker identification tool, Hybrid Feature Screening (HFS), to construct a candidate feature set for downstream machine learning models. The pre-screened candidate features from HFS are further refined using a computationally efficient permutation-based feature importance test employing machine learning methods to flexibly model the potential complex associations between disease outcomes and molecular biomarkers. Through extensive numerical simulation studies and practical applications to microbiome-associated weight changes following bariatric surgery, as well as the examination of gene-expression-associated kidney pan-cancer survival data, we demonstrate HiFIT's superior performance in both outcome prediction and feature importance identification. AVAILABILITY AND IMPLEMENTATION: An R package implementing the HiFIT algorithm is available on GitHub (https://github.com/BZou-lab/HiFIT). SUPPLEMENTARY INFORMATION: Supplementary materials are available at Bioinformatics online
Adolescent Dating Violence and Suicide Planning Among Girls in US High Schools: An Intracategorical Intersectional Analysis by Race and Ethnicity.
Get PDFObjectives. To examine associations between adolescent dating violence (ADV) and suicide planning among girls and differences by race/ethnicity. Methods. Data were from the 2021 Youth Risk Behavior Survey (YRBS), a cross-sectional, nationally representative study of 9th- to 12th-grade adolescents from US high schools (n = 3886). We used weighted logistic regression to examine associations between ADV and suicide planning and assess moderation by race/ethnicity. Results. Compared with girls who did not experience any ADV, girls who experienced both physical and sexual ADV had greater odds of making a suicide plan (adjusted odds ratio [AOR] = 5.35; 95% confidence interval [CI] = 3.27, 8.74), and the effect size was larger than for experiencing either type of ADV alone. The relationship between sexual ADV and suicide planning was exacerbated for Latina girls (AOR = 6.36; 95% CI = 3.96, 10.19) compared with White girls (AOR = 2.51; 95% CI = 1.45, 4.35). Conclusions. Experiencing any form of ADV increases the odds of suicide planning among girls, with stronger impacts for Latina girls experiencing only sexual ADV. Public Health Implications. Prevention of suicide planning for Latina girls who experience sexual ADV may be strengthened by integrating contextually tailored suicide prevention into prevention programs addressing healthy relationships and prevention of sexual violence. (Am J Public Health. Published online ahead of print May 1, 2025:e1-e9. https://doi.org/10.2105/AJPH.2025.308043)
Changepoint Analysis on Marathon and Half Marathon Data: An Insight on Annual Record Trends and Recent Major Marathon Performances
Get PDFSuper shoes have been a recent phenomenon in the running community, with many top racers relyingon them to boost their running economy. Many biological studies tackle this sensation, suggesting super shoesimprove running efficiency. However, is there statistical evidence that these shoes are making a difference inrecent marathon performances? In addition, can this recent phenomenon be generalized to observe significantchanges in the trend of marathon records over the course of the last few decades? Through the use of ExtremeValue Theory, Bayesian statistics, and multiple changepoint models, these questions are tackled in a two-partstudy. The first part analyzes the historical trends of marathon records, detecting no single event that haschanged the trajectory of the fastest marathon times in a given year. The second part analyzes the recentimpact of super shoes on marathon performances, establishing a correlation between the introduction ofsuper shoes in 2017 and a significant difference in performance trends.Bachelor of Scienc
Growing With the Flow: Interactions Between Exposure, Currents, and Intertidal Oyster Reef Growth
Get PDFIntertidal oyster reefs are vital to marine ecosystems, providing critical services such as water filtration, habitat creation, coastal protection, and nutrient cycling. Oyster reef restoration projects are increasingly being aimed at reducing shoreline erosion; however, if the reef cannot keep pace with sea-level rise its effectiveness at dampening waves will diminish. To inform restoration efforts, this study aims to identify the optimal flow and exposure conditions conducive to reef growth by combining high spatial resolution mapping of decadal reef growth with weekly flow and water level measurements. We placed four tilt-current meters around three intertidal patch reefs in Back Sound, North Carolina and recorded the speed and heading for a two-week deployment period. Using observations from co-located water level loggers, we parsed velocities into rising and falling tides to determine tidal flow dependance. We produced four digital elevation models collected between July 2013 and June 2024 to quantify reef growth patterns in relation to the elevation, orientation, and flow velocities. The 95th and 98th percentiles of reef elevations outpaced relative sea-level rise, raising 0.015 m yr -1 from 2013 to 2024. Average flow was largely bi-directional and ranged from 0.01 to 0.30 m s-1. Speeds were maximized at water-depths in the intertidal range, with consistently slower flows at slack tide not related to wind velocity or direction. Surrounding bathymetry and flow routing likely plays a role in imposing velocities at each site, with the relatively deep channel to the north of the reef potentially enabling the higher velocities observed by the north facing sensor. Additionally, Hurricane Florence in 2018 likely physically reshaped the reef nearest this channel, as evidenced by the formation of a large shell hash berm after the storm. Our observations suggest a relationship between flow velocities, reef aerial exposure, and reef growth that can help guide restoration efforts to target sites that maximize reef accretion with accelerating sea-level rise.Bachelor of Scienc