22689 research outputs found
Sort by
The Latino Postsecondary Aspiration and Enrollment Gap and Leadership Implications in Cascadia Public Schools
Get PDFIn Cascadia Public Schools, a low-income and racially diverse school district just south of Seattle, Washington, students have high aspirations to attend postsecondary programs after high school (95%). However, only 49% of graduates directly enroll in a postsecondary program after high school, and only 35% of Latino students, the district’s largest demographic group. A review of the literature demonstrates how Latino students’ postsecondary decisions are influenced by their academic achievement, depth of college knowledge, and the strength of their college-going identity. These individual factors are shaped by relationships with teachers, counselors, friends, family, and their own identity development. Ecological systems theory provides a lens to understand how these individual factors are shaped by experiences within classrooms and schools, and how these relationships are influenced by broader policy and historical barriers that have prevented people of color and individuals from low-income backgrounds from accessing college.
A needs assessment was conducted to better understand the aspiration and enrollment gap for Latino students in Cascadia Public Schools. The study included a quantitative statistical analysis of student transcript information and survey data, as well as qualitative interviews with principals and assistant principals about culturally responsive mentoring, advising, and effective school leadership practices. The results found no statistically significant relationship between Latino students’ college-going identity or academic achievement and their enrollment in a postsecondary institution. Qualitative interviews revealed that while principals perceive teachers and counselors care deeply about their students, they often hold low expectations for their futures. Principals expressed a strong belief in equity and postsecondary access but engaged in few formative assessment practices to monitor college access strategies.
The intervention is a coaching guide based on research identifying principals as having a significant impact on student achievement. The guide supports a principal supervisor and principal to engage in plan-do-study-act (PDSA) cycles with a networked improvement community to implement culturally responsive college advising at their school. Through this work, principals develop their ability to monitor the implementation of improvement strategies and collaborate with a diverse stakeholder team. While focused on increasing Latino students’ postsecondary enrollment, these leadership practices are transferable to broader school improvement efforts
Nutrition Interventions in Pregnancy and the Burden of Low Birth Weight in Bangladesh
No full textBackground: Maternal undernutrition in Bangladesh contributes to high incidence of low birth weight (LBW) infants, who face life-long health, growth, and development challenges. Multiple micronutrient supplements (MMS) and balanced energy-protein (BEP) in pregnancy can prevent LBW, but the best ways to target and evaluate these products in high-need, low-resource settings remains unclear.
Objectives, Methods and Results: This dissertation addresses three aims. Aim 1 tested whether late pregnancy diet quality modifies the effect of MMS vs iron-folic acid (IFA) on LBW. MMS may fill micronutrient gaps from poor-quality diets, but this had never been formally tested. Data from 19,061 women in the JiVitA-3 community-cluster randomized controlled trial (RCT) of MMS vs IFA were analyzed using log-binomial Generalized Estimating Equations. MMS demonstrated more pronounced effects among women with lower dietary diversity scores [DDS= 1: RR LBW: 0.86 (0.81, 0.91)], compared to women with higher scores [DDS = 7: RR: 0.92 (0.84, 1.00)].
There is growing advocacy for targeting nutrition interventions and Aim 2 explored community perceptions of targeting to inform feasibility of future programs. In the context of the TargetBEP RCT of targeted BEP vs MMS, in-depth interviews and ranking exercises were conducted with 32 women participants and 26 family members, and 6 focus group discussions with community health researcher workers (CHRWs). All pregnant women were viewed as vulnerable. Participants prioritized inadequate diets and poverty—rather than thinness or short height—as indicators of nutritional vulnerability. CHRW counseling improved understanding of the importance of pregnancy weight gain.
Aim 3 addressed the lack of an updated disability weight (DW) for LBW; DWs are essential for calculating Disability Adjusted Life Years (DALYs). A multi-stage decision-analytic model with probabilistic sensitivity analyses yielded a revised DW for LBW of 0.129 (0.076, 0.202).
Conclusions: MMS fills dietary micronutrient gaps and should be prioritized for communities with low dietary diversity. Community members already use diet quality and poverty to judge need; strengthening CHRW training can align program targeting with local perceptions. The new LBW DW suggests Bangladesh bears a heavier health burden than global estimates imply, and new cost-effectiveness analyses of maternal nutrition interventions should be conducted
DYNAMIC, CELL TYPE-SPECIFIC RESPONSES TO RETINOIC ACID IN HUMAN RETINA AND RETINAL ORGANOIDS
No full textRetinoic acid (RA) is a prominent regulator of regionalization and cell fate
specification during human retinal development. Despite this, how RA modulates gene
expression and development of retinal cell types is poorly understood. Here, we use
human retinal organoids, combined with single-nucleus RNA sequencing (snRNA-seq),
to examine the effects of RA treatment on retinal development at a cell-type-specific and
temporal level. We then apply our findings to an atlas of the fetal retina, shedding light
in the dynamics of RA signaling in human development. Our results reveal distinct, cell
type-specific gene expression responses to RA. Cones, rods, bipolar cells, and
horizontal cells exhibited more advanced developmental trajectories in the absence of
RA. Conversely, retinal ganglion cells (RGC) were more mature with RA treatment.
Genes regulated by RA showed dynamic expression patterns during development,
peaking early and decreasing around gestational week 14, suggesting a decrease in RA
signaling during fetal development. These findings suggest that RA signaling in the
human retina is critical for early retinal development, and that differential RA signaling
influences the maturation of distinct retinal cell types. Our study provides new insights
into the temporal regulation of RA in the human retina and informs how organoid
protocols can be improved for their utility as a regenerative therapy
Oral history of K.B.
No full text"K.B.” is a member of the graduating class of 2025. In this oral history, she discusses growing up in Hartford, Connecticut with her parents, who met in California after her father immigrated to the United States from Jamaica. She shares her experience attending an engineering magnet high school in Hartford and the impact of the COVID-19 pandemic on her high school experience, as well as her early interest in social justice, the humanities, music,
and playing volleyball. She talks about her academic journey at Hopkins as a Computer Science major, with a particular interest in cryptography. She also shares her experience navigating Hopkins as a Black student and learning to advocate for herself as a student with a disability
Oral History Interview with Larry R. Churchill
No full textThis interview with Professor Larry Churchill, PhD, is part of “Moral Histories: Voices and Stories from the Founding Figures of Bioethics,” an oral history project of the Johns Hopkins Berman Institute of Bioethics. Prof. Churchill is the Ann Geddes Stahlman Professor Emeritus of Medical Ethics and Professor Emeritus of Medicine, Religion, and Philosophy at Vanderbilt University. He is the author of several books, notably Everyday Ethics, What Patients Teach, Healers, and Bioethics Reenvisioned. His areas of expertise include clinical medical ethics, endof-life care, healthcare rationing, justice in healthcare, and human subject research. Churchill discusses his upbringing in Hector, Arkansas, and his education at Southwestern (now Rhodes College) and Duke University. He reflects on his early career as a Presbyterian minister and his transition to bioethics. Churchill discussed his career at the University of North Carolina at Chapel Hill, including the establishment of a social medicine department and the creation of an ethics center that highlighted the importance of humanities and social sciences in medical education. Churchill detailed his extensive work in clinical ethics rotations while at Vanderbilt and created the Center for Biomedical Ethics and Society. He also describes his work in bioethics as it relates to healthcare reform; he recalls scholarship of his in which he advocated for universal coverage based on self-interest rather than altruism. He discusses the Clinton era healthcare reform failure as being due to vested interests and the persistence of healthcare lobbyists.
He emphasized the role of narrative in ethics and the need for a holistic approach that includes reason, memory, imagination, and emotions. Churchill also touched on the challenges of healthcare commodification and the importance of respect and cultural humility in bioethics. Professor Churchill shares his recent work that focuses on the significant health impacts of climate change and the need for bioethicists to address it. The interview concludes with Churchill reflecting on aging and his current work which integrates his bioethics and philosophy training with a holistic view of life that includes gratitude, awe, spiritual growth, and compassion
ALGORITHMS FOR IMPROVING ACCESSIBILITY AND REPRESENTATION IN LARGE GENOMIC STUDIES
Get PDFGenomics has seen rapid growth in recent years, resulting in countless breakthroughs that have tremendously improved our understanding of ourselves and of the world. There has been an exponential increase in the amount of data being generated and a similar increase in the number of people who are looking for answers in that data.
This thesis first addresses the ballooning computational overhead that comes with the growth in genomic data. We first present a learned index structure approach to more rapidly query large genomic data structures. We utilize the underlying structure of a large data structure to fit a model that can, with high accuracy and precision, predict a narrow range in which a query can be found. This limits the issues encountered when attempting to load large sections of data into memory, and results in an approach that can outperform binary search.
We then present alignment- and index-free approaches to classifying sequences. Traditional microbial sequence classification approaches are largely alignment or index-based, which have expensive comparative and pre-compute steps respectively. We propose sketching and sampling approaches with reduced computational requirements that achieve comparable accuracy.
The second half of this thesis focuses on the representation in genomic data. We first overview the evolution of human reference genomes, from the first linear references to the complete telomere-to-telomere human genome, and on to expanded pangenome references.
Finally, we study the representation of South Asian variation in reference genomes. Using existing short read data from 640 individuals, we investigate their variation relative to widely used linear and pangenome references through the assembly and placement of unmapped reads. We assemble hundreds of megabases of sequence in tens of thousands of large contigs against even the most complete reference genomes, and through placing nearly 20,000 contigs we find thousands of gene intersections and potential GWAS interactions, and also demonstrate the functional potential of the tens of thousands of unplaced contigs.
This thesis presents approaches to lower some of the burden associated with rapidly growing genomic datasets, and to better understand the improvements made by and limitations present in widely used human genomic data
Advancing Automated Methods for the Detection and Monitoring of Neurological Disorders Through Speech and Multimodal Analysis
No full textNeurodegenerative disorders (NDs) are progressive conditions marked by neuronal loss, leading to cognitive and motor decline. While currently incurable, early detection is critical for initiating timely interventions that can slow disease progression and improve quality of life. This work addresses key limitations in current approaches developed to detect and monitor NDs using speech and other complementary biosignals. Existing methods often rely on small, homogeneous datasets collected post-diagnosis, limiting the generalizability of findings and missing opportunities for early intervention. Moreover, the dominant use of unimodal analysis overlooks the complex, multimodal nature of NDs, which affect cognitive, motor, and linguistic functions in tandem. To address these challenges, we introduce two novel corpora: ParkCeleb and NeuroLogical Signals. ParkCeleb is a unique longitudinal speech dataset featuring recordings from celebrities diagnosed with Parkinson's Disease (PD), spanning from up to 10 years before diagnosis to 20 years post-diagnosis. Machine-learning modeling reveals patterns characteristic of PD-related dysarthria up to 10 years before diagnosis. Moreover, a longitudinal analysis identifies speech changes associated with disease progression, such as reduced pitch variability and slower speech rate. The NeuroLogical Signals corpus includes synchronously collected data across multiple modalities—speech, eye movement, handwriting, and gait. We leverage this dataset to develop and evaluate novel biomarkers by integrating speech and eye movement signals during different neuropsychological tasks. Several of these biomarkers demonstrate robustness across tasks and offer enhanced subject characterization compared to traditional unimodal metrics. In addition, classification models combining speech and eye movement consistently outperform unimodal models, highlighting the complementary value of these biosignals. Finally, to evaluate whether findings reported in the literature translate beyond isolated studies, we introduce a rigorous framework to assess the robustness and generalizability of speech-based models and biomarkers. By testing performance across diverse datasets, languages, and recording conditions, this framework identifies biomarkers and models that generalize across patient populations, laying the groundwork for reliable and clinically meaningful applications. Collectively, these contributions advance the development of scalable, multimodal, and personalized tools for early detection and monitoring of NDs—paving the way for earlier intervention, improved clinical outcomes, and more precise patient stratification in research and practice
Understanding the impact of post-separation abuse on children's health and flourishing
No full textBackground. Children’s health is profoundly impacted by exposure to intimate partner violence (IPV). Maternal IPV survivors and their children often face ongoing abuse following separation (“post-separation abuse” or “PSA”). Significant gaps exist in IPV measurement related to children and the post-separation context.
Objectives. (1) To explore post-separation experiences of maternal IPV survivors. (2) To develop a psychometrically valid and reliable measure of PSA. (3) To assess health needs of children (ages 6-17) whose mothers report exposure to PSA.
Methods. Utilizing an exploratory sequential mixed methods design, this study recruited a community-based, convenience sample of maternal IPV survivors in the US (N = 33) with children ages 6 to 17 for semi-structured interviews about their post-separation experiences, family court, and their children’s health and flourishing. The second phase of this study involved scale development, with items based on qualitative interviews and refined with multi-disciplinary expert review (N = 11). Finally, the items were tested in a community-based, convenience sample of family court involved maternal survivors (N = 497). Exploratory factor analysis using iterative principal factor analysis assessed construct validity, and Cronbach’s alpha assessed subscale reliability. Child health outcomes were measured using items from the National Survey of Children’s Health (NSCH): children’s special health care needs, unmet mental health needs, stomach/intestinal problems, chronic pain, and ever diagnoses of depression and anxiety.
Results. This study resulted in the development and validation of the Healthcare, Economic, and Legal Post-Separation Abuse and Coercive Tactics (HELP-T) Scale, with 3 subscales for 22 items. The subscales had strong reliability with Cronbach’s alphas from 0.82 to 0.89. Children with mothers exposed to more frequent post-separation abuse faced a dual burden: greater odds of being unable to obtain mental healthcare coupled with greater odds of special healthcare needs, functional difficulties, and mental health diagnoses.
Conclusion. This study provides strong evidence of the burden of ill health borne by children exposed to post-separation abuse and provides a substantial contribution to the literature in improving our understanding of how children’s health is harmed in the context of post-separation abuse
Ecologizing Modernism: Writing with the Nonhuman in Manchuria, 1910–1945
No full textThis dissertation examines literature produced in and about Manchuria in the first half of the twentieth century through the lenses of ecocriticism and transnational modernism. During this transformative period, literary modernism emerged as a powerful means of grappling with the upheavals of modernity, both formally and politically. Introducing the concept of eco-modernism—literature that enacts formal innovation while engaging with ecological transformation—I propose that modernist experimentation is not only a response to human crises but is also deeply ecological in nature. The modernist concern with fragmentation, nonlinearity, and shifting perspectives reflects not just fractured subjectivities but also a sustained negotiation with the nonhuman world.
Focusing on Chinese and Russian authors writing in and about Manchuria, I analyze texts from two distinct literary traditions—Chinese native-soil writers of the Northeast and Russian émigré and colonial authors—who, despite differing cultural and political positions, were equally immersed in Manchuria’s shared landscape. Through close readings of works by Xiao Hong, Duanmu Hongliang, Yi Chi, Nikolai Baikov, Vladimir Arsenyev, and Mikhail Prishvin, I show how their writings bring nonhuman actors—goats, foxes, tomatoes, ginseng, rivers, forests—into the center of narrative structure and ethical reflection. By examining motifs such as human-animal alliances, embodied care, and aesthetic experimentation grounded in natural environments, I argue that these authors write with nonhuman nature, not merely about it. This dissertation highlights how both Chinese and Russian writers challenged dominant paradigms-nationalist realism and colonial natural history—by crafting an eco-critical modernist vision grounded in multispecies entanglement. Their works register and reimagine the ecological consequences of capitalist development, war, and empire, often through sustained attention to animals, plants, and rural spaces. I propose a revival of natural history as a generative mode of thinking across literature and science. This reflects a residual yet vital impulse in the works studied: to attend closely to the living world, not only as setting or symbol, but as a co-author of thought, form, and resistance
Cosmology Large Angular Scale Surveyor: From Instrumentation to Beyond the Standard Model
No full textLarge angular scale polarized microwave emission is key to probing both Galactic structure and cosmological phenomena. Polarized Galactic sources, including synchrotron, thermal dust, and potentially anomalous microwave emission, trace the Galactic magnetic field and the interstellar medium. A deeper understanding of the Galactic signal will aid in unraveling the polarized cosmic microwave background (CMB) through effective component separation. CMB E-modes at ℓ<20 offer strong constraints on the reionization optical depth, while B-modes potentially hold direct evidence of inflation through primordial gravitational waves. The Cosmology Large Angular Scale Surveyor (CLASS), located in the Atacama Desert of northern Chile, is a telescope array that surveys the sky with single-frequency-band telescopes centered at 40 GHz and 90 GHz, as well as a dual-band 150/220 GHz telescope. Ground-based observations face challenges in recovering large-scale information due to low-frequency 1/f variations from atmospheric, instrumental, and calibration drifts. CLASS maintains long-term stability via front-end polarization modulators. I will describe the design, fabrication, and performance of a new polarization modulator, the rotating reflective half-wave plate, which nearly doubles the linear-polarization mapping speed of the 90 GHz telescope and helps us better understand systematic errors from the modulation step. I will also present an analysis of polarized synchrotron radiation based on CLASS 40 GHz and WMAP K/Ka/Q-band (at 23/33/41 GHz) data, featuring sensitivity-improved polarization maps at 40 GHz and the spatial variation of the polarized Galactic synchrotron spectral index. Finally, I will look ahead to forecast CLASS and LiteBIRD's potential to corroborate four large angular scale temperature anomalies of CMB. We found that the ΛCDM model predicts weak correlations between T-mode and E-mode statistical tests for anomalies, suggesting that future polarization experiments will generate independent measurements that may firm up the significance of the anomalies in temperature, eventually shedding light beyond the ΛCDM model