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Dataset of sulfur isotope data for Murchison meteorite and raw data for standardization and tests related to Murchison meteorite
No full textThis files contains normalized Sulfur isotope data for Murchison samples. First Tab contains processed sulfur isotope data for Murchison meteorite extracts normalized to Canyon Diablo Troilite. Second Tab contains Raw data (uncleaned) this tab also includes analyses of reference materials run on same days as Murchison analyses and analyses of sulfonic acids for tests). Last Tab contains the processing (Normalization) calculation for Murchison data.1. Description of methods used for collection/generation of data: The data were obtained using a ThermoFisher MAT 253 dual inlet mass spectrometer and are the output data from the mass spectrometry software. The software calculates isotopic data and reports them in the delta notation from ion beam intensity ratios using standard sample standard bracketing. The extracts were prepared using protocols described in Labidi et al 2017 (https://doi.org/10.1016/j.gca.2016.09.036).
2. Methods for processing the data: The raw data are processed in the file by first renormalizing the data to sample gas from the international standard reference material IAEA S-1 and then converting this normalization to the Canyon Diablo Troilite Reference scale of Dottin et al 2023 (https://doi.org/10.1029/2022JE007597) using values reported in that paper.
3. Instrument- or software-specific information needed to interpret the data: MS Excel, or other software able to read .xlsx format
4. Standards and calibration information, if appropriate: See 2.
5. Environmental/experimental conditions:
6. Describe any quality-assurance procedures performed on the data: The mass spectrometry uncertainties are reported for each value. All values standardized against international standard reference material IAEA S-1 Canyon Diablo Troilite (CDT).
7. People involved with sample collection, processing, analysis and/or submission:
James Farquhar
Amaury BouyonNASA 80NSSC19K0516 - UNIVERSITY OF MARYLAND - COLLEGE PAR
Rhythms of the Blue Ridge: Historic African American Entertainment Venues of Western Maryland
No full textThroughout the twentieth century, musical innovations such as the blues, jazz, and rock n’ roll were being fostered on the edges of cities and towns in African American communities, separated from white society by racially restrictive housing and zoning policies. Within these communities, entertainment venues catering to a Black clientele were established by influential Black entrepreneurs. These spaces became the landscape of the Chitlin’ Circuit– an unofficial network of establishments that were safe for traveling Black artists and patrons alike. Because Maryland is uniquely situated between major influences of the African American entertainment business in Washington, DC, and New York City, the state became a geographic and cultural crossroads for Black culture. Even as Jim Crow-era segregation took hold throughout the United States, Maryland became simultaneously a place of great racial strife and respite. This study identifies and contextualizes the African American entertainment venues of Western Maryland– a region that, despite having the lowest Black population in the state during the period of interest (1900-1960), still fostered vibrant Black communities and cultural traditions
Dataset for Figures in Microwave Microscope Studies of Trapped Vortex Dynamics in Superconductors
No full textAll experimental data were collected using a spectrum analyzer (Aaronia RSA250X). The theoretical data were created using the Time-Dependent Ginzburg-Landau (TDGL) model described in Section III of the paper.This is the dataset used to create figures in the paper: Microwave Microscope Studies of Trapped Vortex Dynamics in Superconductors.Funding Sources:
Department of Energy/High Energy Physics Grant No. DE-SC0017931
Army Research Office/Foundations of Superconducting Digital Logic Grant No. ARO W911NF-24-1-015
Topological Skeletonization Scripts for Assessing Estimated Malaria Parasite Migration Contours Under Sparse Sampling
No full textWe have developed a sample filtering framework that applies topological skeletons for a contour region and kernel density estimation based on malaria parasite sampling locations to assess malaria parasite sample density for each contour and filter contour regions with lower sample density. The Topological Skeletonization Scripts package provides two reproducible Jupyter notebooks that convert Effective-Migration-Surface (EEMS) contour rasters into vector-ready topological skeletons.Malaria parasite gene flow simulation models that utilize georeferenced genomic data have become key tools for inferring parasite migration patterns and diversity through simulation-based approaches. However, the accuracy of the models’ outputs can be compromised when sampling locations are sparse, leading to uncertainty in the results. We have developed a sample filtering framework that applies topological skeletons for a contour region and kernel density estimation based on malaria parasite sampling locations to assess malaria parasite sample density for each contour and filter contour regions with lower sample density. The Topological Skeletonization Scripts package provides two reproducible Jupyter notebooks that convert Effective-Migration-Surface (EEMS) contour rasters into vector-ready topological skeletons. The topo_ske3spots.ipynb script operates on a simulated hexagon-shaped barrier example scenario produced using msprime, a population genetic simulator of ancestry and DNA sequence evolution, while the topo_ske_cam.ipynb notebook processes empirical Plasmodium falciparum malaria parasites collected in Cambodia from 2008 to 2013 (data archived as part of the MalariaGen Community Project). Each notebook implements automated thresholding, morphological cleaning, medial-axis skeletonization (scikit-image), and exports the results as aligned GeoTIFFs, GeoJSON polylines, and diagnostic plots. Developed in Python 3.9 and tested on macOS 10.15 under a Miniconda-managed environment, the workflows utilize open-source libraries (GDAL/rasterio, GeoPandas/Shapely, NumPy, OpenCV).National Science Foundation under Grant no. BCS204980
Dataset for Figures in Robust Wave Splitters Based on Scattering Singularities in Complex non-Hermitian Systems
No full textAll experimental data in Robust Wave Splitters Based on Scattering Singularities in Complex non-Hermitian Systems were collected using a Keysight model N5242B microwave vector network analyzer (VNA). The theoretical data were created using the random matrix theory model described in supplementary material section VIII of the paper. All raw data collected was the 2x2 scattering matrix S measured over many different parameters, or the voltage values measured at the receivers of the VNA. In the attached data files, the raw S data was processed into det(S) values by calculating the determinant of the scattering matrix for all parameter space measured, and the voltage values measured at the receivers were processed into input/output power ratios and phase differences. The data used to create each figure was saved in the corresponding .mat data file using matlab. Additional details are specified in the paper.This is the dataset used to create all the figures in the paper: Robust Wave Splitters Based on Scattering Singularities in Complex non-Hermitian Systems.NSF/RINGS Grant No. ECCS-2148318
ONR Grant No. N000142312507
DARPA WARDEN Grant No. HR00112120021
Department of Energy Grant No. DE-SC0024223
US-Israel Binational Science Foundation Grant No. BSF202215
A Swarm of WASP Planets: Nine giant planets identified by the WASP survey
No full textThe Wide Angle Search for Planets (WASP) survey provided some of the first transiting hot Jupiter candidates. With the addition of the Transiting Exoplanet Survey Satellite (TESS), many WASP planet candidates have now been revisited and given updated transit parameters. In the accompanying paper, we present 9 transiting planets orbiting FGK stars that were identified as candidates by the WASP survey and measured to have planetary masses by radial velocity measurements. Subsequent space-based photometry taken by TESS as well as ground-based photometric and spectroscopic measurements have been used to jointly analyze the planetary properties of WASP-102 b, WASP-116 b, WASP-149 b WASP-154 b, WASP-155 b, WASP-188 b, WASP-194 b/HAT-P-71 b, WASP-195 b, and WASP-197 b. These planets have radii between 0.9 R_Jup and 1.4 R_Jup, masses between 0.1 M_Jup and 1.5 M_Jup, and periods between 1.3 and 6.6 days
NIGHTHAWKS: POLITICS, INTERSERVICE RIVALRIES, AND MARINE CORPS SURVIVAL
No full textThis thesis explores the efforts of the United States Marine Corps (USMC) to secure its institutional survival in the face of post-World War II defense unification pressures and existential threats. The study highlights the critical role of Marine Helicopter Squadron One (HMX-1) in establishing the Corps' continued relevance through helicopter innovation, both in combat and non-combat roles, particularly in amphibious warfare and presidential transport. Amid interservice rivalries and political resistance, HMX-1 symbolized the Marine Corps’ adaptability and strategic importance. The research investigates the political dynamics, technological advancements, and lobbying efforts that enabled the USMC to preserve its unique identity and operational significance. It argues that HMX-1 was instrumental in shaping the Corps' enduring role in national defense
South Asian American women and leadership: How race and gender identity influence perceptions and enactment of leadership
No full textThis dissertation explored how second-generation South Asian American women describe, define, and enact leadership. Using intersectionality and DesiCrit as a theoretical framework, this narrative inquiry study was guided by the following research questions: (1) How do racial and gender identities influence second-generation South Asian American women college students’ descriptions of leadership? (2) How do racial and gender identities influence second-generation South Asian American women college students’ enactment of leadership?Ten South Asian American women college students from a university in the Mid-Atlantic participated in this study. Participants completed one interview and submitted a participant-generated visual method (PGVM) depicting their conceptualizations of leadership. This dissertation includes individual narratives for each participant, outlining their unique experiences, perspectives, and meaning-making related to leadership and their identities, as well as a collective narrative outlining themes that cut across the participants’ individual narratives. The themes from the collective narrative include: (1) learning leadership, particularly through women in their communities; (2) connections to South Asian community and identity; (3) navigating a bicultural identity and stereotypes; (4) leadership grounded in community; (5) leadership grounded in advocacy; and (6) developing an integrated South Asian American woman leader identity
"IN MY EXPERIENCE…": AN EXPLORATION OF HOW RURAL, BLACK HIGH SCHOOL STUDENTS' K-12 EXPERIENCES INFLUENCE THEIR DECISIONS TO PURSUE OR NOT PURSUE TEACHING AS A CAREER
No full textThere was a time in the US when Black youth revered their Black teachers and looked to them as models of excellence (Foster, 1997). In fact, during the 1950’s, nearly half of all Black professionals were teachers who taught Black students in segregated schools (Cole, 1986). However, following the Brown decision, thousands of Black teachers were dismissed (Fenwick, 2022) and racist teacher licensure testing was implemented to ensure otherwise qualified Black teachers would not be hired at recently integrated schools (Fenwick, 2021). Since then, Black students have been educated by an overwhelmingly white teacher workforce. Currently in the US, only 2% of K-12 public school teachers are Black men and only 5% are Black women (U.S. Department of Education, 2016). Although extant research explores barriers for Black pre-service students’ teacher preparation program completion (Walker, 2020; Dinkins & Thomas, 2016), and factors influencing Black in-service teachers’ turnover (Carver-Thomas & Darling-Hammond, 2017; D’amico et al., 2017), few studies seek to understand why most Black high school students never choose to pursue teaching as a viable career in the first place. As we attempt to remedy the systemic failures in US educational policy and practice, and repair the broken Black teacher pipeline, it is important to understand why Black high school students do or do not choose to teach.Drawing on Lortie’s (1975/2020) notion of teaching as an apprenticeship of observation, this study sought to illuminate what Black, rural, high school students observed during their K-12 schooling, and how those observations influenced their decisions to pursue or not pursue teaching as a career. Utilizing Critical Race Theory and Black Critical Theory, this study drew attention to the ways systemic racism and anti-Blackness influenced their decision-making processes as they navigated racially heterogenous rural schools with mostly white teachers and administrators. Using qualitative study methods, including individual and focus group interviews, all six participants shared stories that detailed their experiences in schools and how those experiences influenced their perceptions of teachers and teaching. The research questions guiding this study were (1) How do the K-12 experiences of rural, Black high school juniors and seniors influence their decisions to pursue or not pursue K-12 teaching as a career path? (1a.) How do they describe their own schooling experiences, particularly as related to interactions with teachers, curriculum and instruction, and discipline? (1b.) How do they describe and perceive the impact of race and racism on their schooling experiences and how do those perceptions impact their view of the teaching profession? (1c.) In what ways do their prior schooling experiences and conceptualizations of teaching and teachers influence their decision to pursue or not pursue teaching? (2) How can study participants’ experiences and understandings inform strategies for increasing the number of Black high school students who pursue K-12 teaching as a viable career path?
My findings highlighted the implications of being a Black student in a predominantly white and rural region, participants witnessed and experienced psychological harm in schools, their perceptions of the teaching profession, Black students’ attractors to and deterrents from teaching, and participants proposed solutions for increasing the viability of teaching for Black high school students. Overall, the study found that as Black students are deciding whether or not teaching is a viable career option, positive student-teacher relationships are crucial, teachers’ job satisfaction matters, and high school teacher preparation programs make a difference. The findings provide insight into the ways Black high school students’ experiences in schools influence their perceptions of teachers and the teaching profession, and how those perceptions influence their decisions to pursue or not pursue teaching as a career
Essays on Gender Inequalities and the Economic Impacts of Climate Change
No full textClimate change is accelerating the frequency and intensity of extreme weather events such as floods, heatwaves, and droughts. In 2019 alone, 4.5 billion people were exposed to extreme weather events, marking a 12% increase from 2010, with South Asia as the hardest hit region (Doan et al., 2023). These climate shocks affect various dimensions of a household’s well-being, such as finances, livelihoods, and health, with the potential to reverse hard-won social and economic gains. They have particularly severe consequences for women, who are often at the frontline of climate crises due to existing social and economic inequalities.
This dissertation examines the ways in which climate change intersects with gender inequalities across multiple dimensions: within the household, during critical life stages, and through policy efforts to bridge gender gaps in educational attainment. Specifically, the three chapters explore how climate shocks affect the distribution of household resources among members (Chapter 1), how extreme heat experienced by mothers during pregnancy affects children’s early-life health (Chapter 2), and how government programs can close gender gaps in secondary education attainment (Chapter 3). Chapters 1 and 2 directly investigate the economic and health impacts of climate change, while Chapter 3 focuses on gender inequality in education—a barrier that affects women’s economic opportunities and may indirectly influence their capacity to adapt to climate shocks in the future. Together, these chapters highlight the interconnectedness of climate change, economic vulnerability, and gender inequality in climate-vulnerable settings.
Chapter 1 examines how climate shocks can have heterogeneous effects on household members' well-being by examining the impact of floods on intra-household resource allocation in Bangladesh, one of the countries most vulnerable to climate change. While much of the existing climate-economy literature examines the effect of climate shocks on household-level consumption (Karim and Noy, 2016), this chapter demonstrates that women’s and children’s material well-being deteriorates relative to that of men in the same household as the share of the household budget available to them declines, while the share allocated to men increases. As the division of the household budget among members is not directly observable, I specify a structural model to estimate the shares of the household budget allocated to men, women, and children and leverage quasi-random variation in flood exposure to examine how these shares respond to a flood shock over time. Using panel data on households combined with geospatial data on flooding, I show that exposure to a flood leads to a reallocation of resources away from women and children—primarily women—toward men, with effects persisting even four years after the shock. As a result, women and children face a greater risk of falling below the poverty line compared to men living under the same roof.
This reallocation of resources is driven by a decline in employment opportunities for women, leading to a decrease in their earnings relative to men’s after the flood, as women are less able to transition to alternative occupations. While both men and women are less likely to work in farming after the flood, men can compensate by working as day laborers, an option less available to women in this context. This limited adaptability for women highlights gendered economic vulnerabilities that climate shocks exacerbate, underscoring the importance of integrating gender-sensitive labor market support into climate resilience efforts to mitigate these hidden intrahousehold inequalities.
Chapter 2 examines how exposure to extremely hot temperatures during pregnancy affects children’s early-life health, which can contribute to long-term economic and social inequalities. This chapter also focuses on the Bangladeshi context, and uses exogenous variation in prenatal temperature experienced by cohorts of pregnant mothers who give birth in the same district and month but in different calendar years. Combining household and child-level survey data with reanalysis temperature data, I find that short-lived spikes in temperature during pregnancy do not significantly impact health in early childhood. However, more prolonged exposure to hot temperatures, especially during the third trimester, decreases their height-for-age z-score, a measure of long-term undernourishment, by 0.186 and increases their probability of stunted growth, a signal of chronic undernourishment, by 6.9 percentage points. This chapter demonstrates that one channel through which the economic and health consequences of climate change materialize is women’s exposure to extreme heat during pregnancy.
Chapter 3 shifts from the direct impacts of climate shocks to examining a policy intervention aimed at reducing gender inequalities in education. In climate-vulnerable settings, improving girls’ education can be an important step toward enhancing future resilience, as education expands women’s economic opportunities and access to information. This co-authored chapter evaluates a government-administered cash transfer program in Pakistan that offered households a monthly stipend conditional on girls’ regular attendance in secondary school (grades 6 to 10). Using administrative school-level data and a regression discontinuity design that exploits the program’s eligibility cutoff based on district-level adult literacy rates, we find that the program increased girls’ secondary school enrollment consistently over more than a decade (2004-2015). These positive effects persisted despite the real value of the cash benefit decreases by more than 60%, suggesting that the program may have influenced household attitudes or contributed to shifting social norms around girls’ education. While this potential climate resilience benefit is not directly tested in this chapter, the policy’s role in reducing gender gaps in education is directly relevant to the broader inquiry into gender inequality in South Asia.
These three chapters collectively illustrate the multifaceted relationship between climate change, economic impacts, and gender inequalities. Chapters 1 and 2 directly show how climate shocks—floods and heat—worsen gendered economic and health vulnerabilities within and across generations. Chapter 3 complements this by showing how policy interventions can reduce the gender gap in education, which may have long-term consequences for women’s economic and adaptive capacity in climate-vulnerable settings. Taken together, my dissertation highlights that addressing gender inequality is a necessary element of effective climate adaptation strategies in contexts where climate change and gender disparities are intertwined