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Insights Into How A C. Elegans Neural Circuit Transitions Between Two Internal States To Produce Egg-Laying Behavior, Shavanie Prashad

Yale Graduate School of Arts and Sciences Dissertations

A challenge in neuroscience is understanding how neural circuits generate and sustain behavior over time. Neural circuits consist of interconnected groups of neurons that process and integrate sensory information to perform specific tasks and behaviors. These circuits organize behaviors by maintaining internal states—stable neural activity patterns influenced by sensory and physiological contexts, as discussed in Chapter One.

To understand how neural circuits generate internal states, we examined how the well-characterized C. elegans egg-laying circuit transitions between inactive and active states to produce egg-laying behavior. The active internal state lasts approximately 2 to 3 minutes, during which one or more eggs …

Identifying How Pseudomonas Aeruginosa Cells Become Primed For Expression Of Type Iii Secretion System Genes, Kristen Alicia Ramsey

Yale Graduate School of Arts and Sciences Dissertations

Pseudomonas aeruginosa is an opportunistic pathogen known to cause acute infections in individuals with epithelial damage or medically placed devices, leading to sepsis or death in immunocompetent and immunocompromised individuals. Like many other Gram-negative bacteria, P. aeruginosa uses a Type III Secretion System (T3SS) to intoxicate eukaryotic cells. This T3SS is essential for P. aeruginosa to establish an infection and avoid clearance by immune cells and is also linked to increased morbidity and mortality in infections. Despite this necessity, activation of the T3SS slows P. aeruginosa’s cell growth and permits innate immune system detection and resulting inflammation. To balance …

Unveiling The Structure Of The Perfect Superfluid Using Correlation Functions, Ananya Rai

Yale Graduate School of Arts and Sciences Dissertations

The sequential clustering of particles into jets provides an algorithmic link between final-state hadrons and the partons from which they originated. Jet substructure techniques allow us to trace the radiation history of jets, offering a powerful framework to probe Quantum Chromodynamics (QCD) across different energy scales. Projected N-point Energy Correlators (ENCs) are a novel class of observables that explore the energy flow within hadronic jets. This thesis presents the first measurements of the two-point (EEC) and projected three-point correlators (E3C) as well as their ratio (E3C/EEC) at √ s = 13 TeV using Run 2 data from the ALICE experiment. …

Development Of Genome-Scale Technologies For Writing And Recoding Cyanobacteria, Laura Beth Quinto

Yale Graduate School of Arts and Sciences Dissertations

Diverse microorganisms have delivered unique solutions in medicine, food, energy, and nutrient cycling through atmospheric gas fixation. Yet despite tremendous progress in model organisms like E. coli and S. cerevisiae, tools for editing and predictably manipulating undomesticated species – which comprise the vast majority of microbes1 – remain scarce. Cyanobacteria, with their light- and CO₂-powered metabolism, hold particular promise for bioproduction, bioremediation, and in situ fertilization, but have been difficult to engineer. Furthermore, many of the most valuable applications of cyanobacteria would involve implementation in an open system. Such strains require two critical safeguards: biocontainment to ensure that their propagation …

Intergenerational Welfare Assessments, Sergi Barcons, Eduardo Dávila, Andreas Schaab

Cowles Foundation Discussion Papers

This paper studies welfare assessments in economies with rich demographic structures. First, we show that perpetual consumption is the only unit that enables interpersonal comparisons in demographically disconnected economies, in which there is no date in which all individuals are concurrently alive. Second, we show that there exist feasible perturbations of Pareto efficient allocations in demographically disconnected economies that feature positive Kaldor-Hicks efficiency gains. Third, we show how welfare gains from reallocating consumption can be separately attributed to an incomplete markets and a demographic component. We use our results to derive new insights in three workhorse intergenerational models: i) Samuelson …

Antibiotic-Resistant Nontyphoidal Salmonella And Campylobacter Isolates Associated With International Travel, Connecticut 2010 – 2023, Shilpa Mudumbe

Public Health Theses

Antibiotics are helpful for limiting duration and complications of Salmonella andCampylobacter isolates in selected age groups and people who are immunosuppressed. However, antibiotic-resistant (AR) foodborne pathogens have been on the rise in the United States over the past 10 years and are often linked to international travel (IT). Long-term trends on AR have not been examined in Connecticut (CT). This study evaluates trends in AR among nontyphoidal Salmonella and Campylobacter isolates in CT from 2010 to 2023 and examines the association between AR and IT. Data from submission of annual systematic samples of CT Salmonella and Campylobacter isolates to the …

A Hierarchical Bayesian Meta-Regression Model For Incorporating Exposure Range Variability, Xiaotong Xu

Public Health Theses

Accurately synthesizing evidence from epidemiologic studies is essential for understanding complex environmental risk relationships and establishing causal relationships. However, the majority of meta-analyses in this area ignore the possibility of variability in risk due to differences in study-specific exposure levels while typical dose-response statistical methods assume a single dose amount per study and not a distribution or range of doses (i.e., exposures). We develop a novel hierarchical Bayesian meta-regression framework that incorporates functional averaging over study-specific exposure ranges and models the underlying exposure-response relationship using a flexible Gaussian process. Using a low-rank predictive process formulation, our approach efficiently projects functional …

Enhancing Dengue Forecasting With Remotely Sensing-Derived Vector Proxies And Random Forest Models: A Case Study For Sri Lanka, Shuyu Ye

Public Health Theses

Dengue fever is a growing global public health threat, especially in tropical and subtropical regions such as Sri Lanka, where seasonal outbreaks impose recurring burdens on health systems. Accurate and timely forecasting of dengue incidence is essential for public health preparedness, yet most existing models suffer from key limitations: they rely on historical case trends without accounting for real-time ecological dynamics, and often require entomological surveillance data that is not consistently available. This thesis addresses these gaps by proposing a machine learning forecasting framework that integrates remote sensing-derived environmental proxies to estimate latent mosquito vector abundance.Using Principal Component Analysis (PCA), …

Economic Burden Of Medically Attended Respiratory Syncytial Virus Illness Among Older Adults, Shirley Zhu

Public Health Theses

ABSTRACTIntroduction: Respiratory syncytial virus (RSV) is a common respiratory pathogen that causes a large burden of disease among older adults. Though there are interventions, the impact and cost-effectiveness of recently licensed RSV vaccines in the United States is not well understood for this population. Thus, reliable estimates on the economic burden of RSV among older adults are needed for future economic analyses.

Objective: The objective of this thesis is to evaluate the cost of medically attended RSV among older adults in the United States.

Methods: Medicare claims data were used to determine average cost per visit for outpatient, inpatient, emergency …

Factors Associated With Non-Transport For Ems Incidents Of Pediatric Head Injuries, Margaret Zhang

Public Health Theses

Background/Purpose:Emergency Medical Services (EMS) is a valuable resource for evaluating, treating, and coordinating care for individuals who have sustained a traumatic brain injury (TBI). Among adults with a TBI, there is frequent refusal of EMS transport. This raises a public health concern because it can put a burden on resource utilization and reveal misperceptions regarding risk following head injuries. Less is known about whether similar patterns of non-transport exist among children with TBIs. The purpose of this study is to describe the epidemiology of pediatric head injuries attended by EMS and to identify factors associated with non-transport for these patients. …

The Prescription Drug User Fee Act (Pdufa): The Design, Evolution, And Challenges Of User Fees And The Reauthorization Process, Therese Ziaks

Public Health Theses

The Prescription Drug User Fee Act (PDUFA) has had a critical role in funding the Food and Drug Administration (FDA) through the form of industry user fees since 1992 with user fees comprising 48% of the FDA’s Fiscal Year 2024 budget. As the FDA faced pressure from Congress and the pharmaceutical industry to reduce drug application review times, the legislation was enacted to provide a funding source in addition to Congressional appropriations so the agency could meet proposed review time goals. As the FDA began to hire additional review staff, reduce application review times, and increase the number of pharmaceuticals …

Nativity Status And Tobacco Use Among Hispanic Adults In The Us, Siyan Zhou

Public Health Theses

Background: Tobacco use is the leading cause of preventable mortality. Understanding the consumption patterns of cigarettes and e-cigarettes, two of the most prevalent and harmful tobacco products, is important for population health. Furthermore, as the nation's largest racial or ethnic minority group, the Hispanic population faces tobacco-related disparities despite overall low prevalence of tobacco use. Since the Hispanic population is not homogeneous, it is important to disaggregate it by ancestry and nativity status to better guide policy and targeted interventions.

Methods: The 2022 September Tobacco Use Supplement to the Current Population Survey (TUS-CPS) included 37,540 participants in the US. Rao-Scott …

Dnabert Reveals Tf Motifs Information In Dna With Attention, Zetong Zhao

Public Health Theses

Traditional motif discovery tools often do not capture cooperative interactions between transcription factors (TFs). This study employs DNABERT, a transformer-based deep learning model, to analyze TF binding sites (TFBS) using attention mechanisms and k-mer tokenization. Fine-tuned on ENCODE ChIP-seq data, DNABERT achieved high predictive accuracy and could identify co-binders such as FOS and JUND through motif enrichment analysis. The model inferred position weight matrices (PWMs) aligning with JASPAR motifs and highlighted the regulatory importance of sequences near gene start regions. Comparisons with BPNet showed strong correlations, which validated DNABERT’s ability to capture TF-specific patterns. While constrained by dataset biases and …

Environmental Health And Justice Impacts Of Data Centers, Yijing Li

Public Health Theses

Background: The rapid expansion in the number and size of data centers, structures that house servers, storage, and networking equipment, in the United States has raised concerns about their environmental and public health impacts as well as the equity implications of where these facilities are built. Objective: This study examined national patterns of data center siting and identified demographic predictors of facility presence. Methods: Operational data center locations were obtained from the Data Center Map database, and county-level sociodemographic characteristics were drawn from the 2023 American Community Survey (ACS) 5-year estimates. A national spatial distribution map was created to visualize …

Evaluating The Impact Of P. Falciparum Genetic Diversity On Pfrh5 Blood Stage Vaccine Protection Through A Multi-Method Approach, Alyssa Agarwal

Public Health Theses

Malaria remains a major global health threat as control efforts have stalled in recent years. Recently, theWHO began recommending two vaccines, RTS,S/AS01 and R21, both of which target the pre-erythrocytic stage of malaria. However, these vaccines are only partially protective and do not protect against the blood-stage of malaria where clinical disease begins. Therefore, a more broadly protective vaccine is still needed. Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) is a leading candidate for next-generation blood-stage malaria vaccines with the most advanced formulation, RH5.1/Matrix-M, recently entering Phase 2b clinical trials. However, historically, malaria vaccine development has been challenged by the …

Period Poverty And The Politics Of Refusal: Building Menstrual Equity Beyond The State Through Mutual Aid, Alanah Armstead

Public Health Theses

This thesis examines period poverty as a consequence of systemic neglect, disproportionately affecting those made vulnerable by intersecting structures of racial, gendered, and economic injustice. Situating menstruation as a public health crisis shaped by policy failure, social stigma, and institutional disregard, this research critiques dominant legal and policy frameworks that approach menstrual equity through a limited scope that overlooks deeper structural inequalities rooted in race and class. This thesis explores how marginalized populations experience legal and welfare systems as sites of surveillance and moral judgment in the context of menstrual equity. Through seven semi-structured interviews with menstrual justice organizers, this …

Enhancing Research Utilization Among Health Policymakers: Lessons From An Executive Certificate Program In Liberia, Felicia Annan-Mills

Public Health Theses

Evidence-based decision-making in health policy is a systematic and transparent approach to policymaking and program design using research evidence and other similar sources. It is essential for developing effective health policies and ensuring that programs align with political priorities and community needs and have strong empirical support for their efficacy and impact. Global health agencies like the World Health Organization and the West African Health Organization have developed guidelines for evidence-based decision-making in health for organizations to use as guiding tools in their policymaking. Regardless, there is still a gap in applying research evidence to practice programs for many countries …

The Mortality Effects Of Daily Ambient Pm2.5 Concentrations By Urbanicity In North Carolina, Pargoal Lisa Arab

Public Health Theses

Daily ambient PM2.5 (particulate matter ≤ 2.5 µm) concentration poses substantial health risks. PM2.5 comes from various sources, leading to regional differences in concentrations. Urban areas generally experience higher PM2.5 concentrations compared to rural areas. However, urban-rural differences in the relationship between daily PM2.5 concentration and adverse health effects remain unclear. The mortality effects of daily PM2.5 concentration across all counties in North Carolina were analyzed both temporally and spatially over a five-year period (2015-2019). A two-stage time series analysis was conducted using a quasi-Poisson regression model with various lag structures to estimate the relative mortality risk for each county. …

Developing An Ethics Curriculum For Humanitarian Research And Practice: A Special Project Mph Thesis, Nour Nedal Al Zouabi

Public Health Theses

Despite increasing ethical challenges in humanitarian crises, most Master of Public Health (MPH) programs offer limited, focused ethics training. Humanitarian emergencies, including armed conflict, mass displacement, pandemics, and climate-related disasters, challenge traditional ethical frameworks, exposing gaps in law, codes of conduct, and philosophical models. This thesis proposes a 13-week graduate course that integrates public health, international humanitarian law, field-based humanitarian practice, research methodology, and moral philosophy to equipe future public health leaders with ethical decision-making processes and skills to navigate complex dilemmas. Through critical engagement with scholarly literature, case studies (Ebola vaccine trials, refugee-camp research), simulations, and guest-speaker dialogues, students …

Laro Kwo-Saving Lives: Evaluating The Role Of Community Health Workers In Healthcare Delivery And Disease Control In Northern Uganda, Brett Albee

Public Health Theses

Background: Northern Uganda faces persistent health challenges due to a legacy of armed conflict, poverty, and fragile health infrastructure. In Pader District, malaria remains the leading cause of under-five mortality, and rural communities face ongoing barriers to accessing timely care. Community health workers (CHWs) serve as critical intermediaries in care delivery, but their effectiveness is limited by structural and resource constraints.Methods: This study employed an exploratory sequential mixed-methods design informed by community-based participatory research (CBPR) principles. Qualitative data were collected through 11 semi-structured interviews and 6 focus group discussions with CHWs across six sub-counties in Pader District. Quantitative data were …

Workplace Violence Involving Practitioners In Veterans Health Administration Emergency Departments: An Analysis Of Reports Submitted To The Vha Disruptive Behavior Reporting System, 2018-2023, Andy H. Chen

Public Health Theses

Background: Published reports and survey data indicate that workplace violence (WPV) in emergency departments (EDs) is on the rise. The severity of WPV incidents and extent to which this trend affects staff differentially by role is less well characterized. This study analyzed workplace violence reports from a nationwide integrated health system to evaluate this observation. Methods: Reports submitted to the Veterans Health Administration (VHA) Disruptive Behavior Reporting System (DBRS) were analyzed. The sample included all reports from over 170 VHA emergency departments across the United States, spanning fiscal years 2018 to 2023. The association between the severity of outcomes and …

Cost-Effectiveness Of New Monoclonal Antibody And Maternal Immunization For The Prevention Of Respiratory Syncytial Virus (Rsv) Disease In Infants: A Systematic Review, Yuwei Che

Public Health Theses

AbstractIntroduction: Respiratory syncytial virus (RSV) remains a major cause of morbidity and mortality among infants and young children worldwide. Given the lack of specific therapeutic treatments for RSV that are suitable for universal use, the development of effective prevention strategies is of paramount importance. Previously, palivizumab was utilized for long-term prophylaxis of RSV infections; however, it was only recommended for specific populations due to its high cost and limited overall effectiveness. In 2023, the U.S. FDA approved RSVpreF maternal vaccine (Abrysvo™, Pfizer), and nirsevimab (Beyfortus™, Sanofi and AstraZeneca) for the prevention of RSV to newborns. Two newly developed interventions have …

Assessing Impact Of Maternal Proximity To Unconventional Oil And Gas Wells On Neonatal Birthweight In Ohio: A Retrospective Cohort Study (2010–2017), Alan Cao

Public Health Theses

AbstractBackground: Unconventional oil and gas development (UOGD) has expanded rapidly in the United States, particularly in states like Ohio, which is home to approximately 5,000 horizontal shale wells and more than 80,000 hydraulically fractured wells since 1952. Although oil and gas extraction has occurred in Ohio for over 60 years, the recent surge in UOGD activity has raised renewed public health concerns about environmental exposures during pregnancy. While previous studies have linked maternal proximity to UOGD with adverse birth outcomes, evidence remains limited regarding its association with birthweight and fetal growth indicators in high-production states such as Ohio.

Methods: We …

The Village Determinants Of Self-Rated Health And Mental Health: A Multilevel Analysis Of Environments In Rural Honduran Villages, Marnen Elizabeth Decker

Public Health Theses

I investigated the associations of village structural, behavioral, and social environments with self-rated health and mental health among adults residing in remote rural villages in the mountainous Copán region of Honduras. I estimated nested multilevel logistic models with 17,318 adults in 174 villages. All models controlled for individual characteristics to distill true village-level effects, and nested structure was employed to facilitate direct comparison across models. Both poor self-rated health and mental health were inversely associated with village size and positively associated with coffee cultivation. Poor self-rated health was also positively associated with friend/adversary tie ratio, and poor self-rated mental health …

How To Increase The Public’S Awareness Of Car-T Therapy? A Pilot Mixed Methods Study, Pei-Chun Cha

Public Health Theses

Background: Chimeric Antigen Receptor (CAR) T-cell therapy is a combination of antibody and T cell receptor (TCR), which allows T-cells to recognize and attack cancer cells. It has shown effectiveness in treating hematological malignancies, but has been less effective for solid tumors. Clinically, it is the first FDA-approved gene therapy as it uses lentivirus to modify the genome of T cells that are infused back into patients. Preclinically, laboratory research is being conducted to enhance this treatment through multiple genetic modifications. Concurrently, integrating community research to understand the public’s awareness of CAR-T is essential for making this therapy more widely …

Assessing The Costs Of Illness Attributable To Leptospirosis, Alyssa Chetrick

Public Health Theses

Leptospirosis, caused by the spirochetes of the genus Leptospira, is a zoonotic bacterialdisease endemic to tropical regions and lower middle income countries (LMICs). Leptospirosis causes an estimated 1 million cases and more than 58,900 deaths annually.(Costa et al., 2015; Torgeson et al., 2015) In addition to human health, leptospirosis significantly impacts animal health and the livestock industry, particularly through reproductive losses, increased treatment costs, and decreased milk production, which exacerbates global insecurity.(Bennet, 2015; Torgeson et al., 2015) The estimated global cost loss to productivity due to disease is estimated at Int$ 29.3 billion. (Agampodi et al., 2023) Because of its …

Scale-Up Of Access To Medication For Opioid Use Disorder For People Who Inject Drugs On Parole In Ukraine: A Modeling Analysis, Brendan Caver

Public Health Theses

Background: Human Immunodeficiency Virus (HIV) and opioid-use disorder have long beendescribed as a syndemic; the two health issues go hand-in-hand to exacerbate each other (Perlman & Jordan, 2018). While the HIV pandemic has improved greatly in many regions such as the United States over the past several decades, it continues to become worse in Eastern Europe and Central Asia. HIV prevalence and opioid dependence are particularly high in carceral settings, but access to opioid agonist therapy (OAT) is extremely limited. This paper shows the results of a modeling analysis undertaken to see the impact of opioid agonist therapy (OAT) scale-up …

The Impact Of Climate Change On Japanese Encephalitis Trends In China, Jiayi Du

Public Health Theses

Japanese encephalitis (JE) is a mosquito-borne viral disease that poses a significant public health threat across Asia, including China. Climate change has been increasingly recognized as a key driver of JE transmission dynamics, influencing mosquito vector distribution and virus proliferation. This study aimed to assess how climatic variables affect the ecological suitability for Japanese encephalitis virus (JEV) transmission, using species distribution modeling with MaxEnt.

Using climate data from WorldClim and JE incidence data from published sources, we applied the MaxEnt model to identify the key environmental predictors of JE transmission and project future risk areas under changing climatic conditions. The …

Association Between Primary Covid-19 Vaccine Type And Booster Uptake Among Incarcerated People In Connecticut: A Retrospective Cohort Study, Michael Condon Elhardt

Public Health Theses

Importance: Booster doses of the COVID-19 vaccine are critical for maintaining protection against SARS-CoV-2, especially in high-risk settings such as correctional facilities. Understanding how initial vaccine type influences booster uptake can inform vaccination strategies in these and other underserved populations.Objective: To assess whether the type of COVID-19 vaccine received for the primary series—either viral vector (Janssen/Jcovden) or mRNA (Moderna/Spikevax or Pfizer-BioNTech/Comirnaty)—was associated with timing or likelihood of booster completion among incarcerated individuals. Design: Retrospective cohort study using survival analysis methods. The study period spanned from February 2, 2021, to May 31, 2023. Setting: Connecticut Department of Correction (DOC) facilities, including …

Exploring Harm Reduction In Treatment: A Qualitative Study Of Methods And Perceptions Among People In Substance Use Disorder Care, Carson Francis Ferrara

Public Health Theses

Amidst the ongoing opioid epidemic and rising overdose deaths, substance use disorder (SUD) treatment has historically prioritized abstinence over harm reduction, creating gaps in patient safety. This qualitative study explores harm reduction integration in formal treatment settings and participant perceptions through 48 semi-structured interviews with individuals enrolled in Project RENEW, a larger cohort study examining factors influencing people in treatment for alcohol use across Connecticut and Georgia. Participants (79% inpatient, 51% court-mandated) described their experiences with harm reduction methods and safety strategies while in treatment. Thematic analysis revealed four key findings: 1) inconsistent access to resources like naloxone and fentanyl …