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Predicting, culturing, and characterizing beneficial and detrimental strains associated with plant phenotypes.
No full textModern agriculture’s reliance on chemical fertilizers has greatly increased crop yields but has also contributed to soil degradation, environmental pollution, and unsustainable resource use. Plant growth–promoting rhizobacteria offer a sustainable alternative, enhancing plant growth through mechanisms such as nitrogen fixation, phosphate solubilization, siderophore production, and phytohormone modulation, while also protecting plants against pathogens and abiotic stresses. However, soil microbial communities are highly diverse and structurally complex, making the isolation of individual beneficial strains challenging. Traditional approaches rely on selective media and labor-intensive phenotypic screening, which often capture only a small fraction of soil diversity. To overcome these limitations, we combined computational predictions with targeted microbial isolation to identify bacteria associated with sorghum growth under low- and full-nitrogen conditions. Using a large-scale field dataset, we integrated 16S rRNA amplicon sequencing, soil properties, and plant phenotype data to perform change-point analysis, revealing bacterial strains correlated with plant traits in the rhizosphere and endosphere. Targeted limiting-dilution culturing of selected field samples yielded multiple candidates, including two Pseudomonas strains, AOC87 and AOC36, predicted to have positive and negative associations with plant performance, respectively. Genome sequencing and functional assays confirmed these predictions: the “positive” strain possessed a complete indole-3-acetic acid (IAA) degradation pathway, while AOC36 carried a type III secretion system. These results demonstrate that computational prediction pipelines can refine the search for functionally relevant microbes, bridging culture-based methods with high-throughput microbiome analysis and enabling mechanistic investigation. Building on these findings, Chapter Four explores the complexities of studying and applying candidate growth-promoting strains, specifically Variovorax, to sorghum. This chapter shows that Variovorax strains exhibit both conserved and variable traits: IAA degradation is broadly conserved, supported by syntenic IAA-degradation operons, yet the kinetics of degradation differ quantitatively across strains. Despite this conserved metabolic capacity, effects on sorghum root elongation were highly variable and did not directly correlate with IAA degradation rates. Instead, variability likely arises from strain-specific factors such as root colonization efficiency, persistence, and interactions with host hormonal pathways, including auxin–ethylene crosstalk. Collectively, these results highlight that while IAA degradation is a core feature of Variovorax, its influence on plant growth is context-dependent and shaped by ecological and physiological interactions with the host. Overall, this thesis establishes a data-driven framework that integrates microbial community analysis, spatial modeling, and strain-level characterization, enabling the discovery and functional testing of field-relevant microbes that impact crop performance
The State Made Desire: Eroticism and Fetish Racecraft in Argentine LGBT Tourism
No full textAs queer theory scholars have noted, around the world, governments use LGBT politics –whether anti-gay or pro-gay rights -- as a medium to advance other political projects. Gay politics become a national symbol tied to modernity, moral authority, and global belonging, often serving as a litmus test for a nation’s progressiveness. Within South America, Argentina stands out not only for its aggressively pro-LGBT policies but also for its exceptional racial politics—namely, the national self-image of “White Argentina,” a vision in which the country imagines itself as white and Eurocentric. This dissertation is an ethnographic exploration of Argentina’s racializing investments in LGBT politics and how these investments are creatively taken up by and unfold among cosmopolitan gay men. Told through the story of “Gay Argentines” and the institutions they inhabit, this dissertation examines eroticism as a relational medium of racecraft within Buenos Aires’ LGBT tourism. The fetishistic identity of the Gay Argentine, racialized and eroticized by gay tango, becomes a living, breathing nexus of white gay masculinity. Gay Argentines, white foreign tourists, and non-white immigrants enact a social dance of racial-sexual domination, with Gay Argentines as a fluid figure within this hierarchy. Gay Argentines are Othered whites who navigate racialized submission to white foreign tourists. At the same time, Gay Argentines are themselves agents of domination—dominating non-white bodies and performing the familiar script of white nationalism. Gay Argentines and the institutions they inhabit illustrate the erotic as political, and pleasure-seeking as the material, affective enactment of those politics. Institutions like the commercial hostel Lugar Gay and the LGBT Nomads tourist collective were founded by Gay Argentines and structured through eroticism. These spaces are contoured by the white national masculinities of “White Argentina” that Gay Argentines embody. Whereas the apoliticism of the leisure-class LGBT Nomads views pleasure as play, the gay refuge of Lugar Gay perceives pleasure as political—conceiving of the potential for the erotic as a transformative and generative force in gay men’s lives. This research illustrates the potential for the relational economies of queer erotics to function as a homonationalist medium for national and geopolitical concerns, while at the same time serving as a racial and gender dialogue for queer politics and of whose desires take center stage
The Employment Benefits of Law Clinics and Externships
Get PDFOne of the reasons law students enroll in a law clinic or externship is the belief that the experience will improve their marketability. In a nationwide survey asking what was driving demand for their courses, 94% of externship directors and 66% of law clinic directors said it was, in part, because students believe those courses improve employment opportunities. Surveys of recent law graduates and employers show that students\u27 perceptions of the positive impact of a clinic or externship experience on their job opportunities upon graduation are well founded. Research shows that clinics and externships do aid graduates in obtaining their first job and that potential employers value entry-level candidates with law clinic and externship experience
Can Bringing Older and Younger People Together Renew Religious Communities?
Get PDFIn fall 2024, CoGenerate, in collaboration with Dr. Cal Halvorsen of Washington University in St. Louis, worked with YouGov to conduct a national survey of 1,500 adults (ages 18 and older) in the U.S. about their religious / spiritual communities, their interaction with older and younger people, and their views on building connections across different age groups. The survey was nationally representative by gender, age, race, education and political affiliation. Our findings reveal considerable age segregation in people’s lives and a strong appetite for intergenerational connection and collaboration – or “cogeneration” – to counter it. They also identify challenges and opportunities for harnessing cogeneration to support spiritual growth and transform religious life
AIRIS: High-Precision Optical Follow-Up Telescope for Gamma-Ray Burst Observation with ADAPT
Get PDFGamma-ray bursts (GRBs) are the most energetic events in the universe, yet their origins and underlying mechanisms remain unclear. Capturing the evolution of GRB afterglows across frequency bands (multi-messenger astronomy) is needed to better characterize these bursts.
The Antarctic Demonstrator for the Advanced Particle-astrophysics Telescope (ADAPT) is a NASA mission led by James Buckley of the WashU physics department, designed to demonstrate a Compton scattering detector for a future space-based gamma-ray and cosmic-ray observer. Planned for a December 2026 weather balloon flight over Antarctica, ADAPT will provide unprecedented sensitivity and wide field of view, producing localizations and polarization constraints on gamma-ray bursts in seconds. However, it has a limited capability to refine GRB localization and cannot provide optical afterglow imaging.
AIRIS (ADAPT Incidence Resolution & Imaging Subsystem) is a fast-slewing optical telescope mounted on the same platform as ADAPT. AIRIS is designed to refine GRB localization sent by ADAPT and provide optical images of their afterglows. AIRIS will respond to GRB triggers identified by ADAPT, slewing up to 30 degrees per second to capture GRB afterglows. Due to AIRIS’ rapidly slewing mount and co-location with ADAPT’s rapid computing pipeline, AIRIS is quickly able to observe the optical afterglows of GRBs. Furthermore, AIRIS’ near-space vantage point, low-noise SONY CMOS sensor, and large aperture 200mm f/1.8 lens, enables the observation of very faint signals. Additionally, AIRIS’s precise localizations will feed into NASA\u27s General Coordinates Network, guiding telescopes worldwide to observe GRB afterglows, contributing to multi-messenger astronomy
Discovery and Functional Characterization of Biomarkers in Clear Cell Renal Cell Carcinoma
No full textNot all tumors are created equally, nor should they be treated as such. Modern research has uncovered a multitude of genetic aberrations, genomic dysregulation, and epigenetic modifications that contribute to cancer. While cancers are classified based on their tissue of origin and may share common features or pathways, the tumor microenvironment is far from uniform. It comprises a dynamic network of cell populations with divergent genomic profiles, all of which collectively drive tumor progression—with some tumors more efficient and aggressive than others. The heterogeneity within these tumors makes it notoriously harder to treat, as standard therapies fail to address the varied mechanisms employed by all subpopulations within the tumor, resulting in treatment resistance, tumor reoccurrence, and poor patient outcomes. However, precision medicine has emerged as a promising strategy to tackle this challenge, offering personalized therapeutic plans based on the biomarkers and molecular profile of a patients tumor. By tailoring treatment targeting specific dysregulated pathways and markers, unique to each tumor biopsy, we can more effectively combat standard therapy-resistant tumor subpopulations and ultimately improve patient outcomes. This study aims to identify, characterize, and evaluate tumor cell-specific markers with potential as both diagnostic biomarkers and therapeutic targets in aggressive clear cell renal cell carcinoma (ccRCC). Kidney cancer encompasses several subtypes, with ccRCC as the most common subtype accounting for more than 80% of all renal cell carcinoma (RCC) cases. Despite initial treatment responses, approximately 70% of ccRCC patients develop resistance within months, and a third of all patients eventually develop reoccurrence. This highlights the need for additional therapeutic strategies and personalized treatment plans. In this study we use single nucleus RNA sequencing, bulk RNA sequencing, and bulk proteomics, to identify and characterize multiple tumor-specific markers, with a functional focus on two key candidates: Ceruloplasmin (CP) and Ubiquitin C-terminal hydrolase L1 (UCHL1). Both CP and UCHL1 are secreted proteins, and our findings associate its transcriptomic overexpression with lower overall survival and increased tumor grade in ccRCC. Through CRISPR-mediated knockout (KO) and shRNA knockdown (KD) cell line experiments, we characterize CP and UCHL1 as modulators associated with epithelial-mesenchymal transition (EMT) and inflammation, two pathways known to drive tumor progression and aggressiveness. Functional assays revealed that UCHL1 KO reduces cell proliferation, colony formation, and tumor growth in cell derived xenograft (CDX) models. Additionally, patient-derived xenograft (PDX) models and in vitro treatment assays demonstrated the therapeutic potential of combining UCHL1 inhibitors with tyrosine kinase inhibitors (TKIs), as the combinational treatment significantly reduced tumor and cell growth compared to single agent treatments. Together, this dissertation identifies CP and UCHL1 as promising biomarkers and therapeutic targets in ccRCC, with a particular emphasis on UCHL1 as a critical driver of tumor aggressiveness and a compelling candidate for combinational therapy strategies
Electrochemically Assisted Wastewater Treatment towards Water Reuse: Mechanism, Performance, and Application
Get PDFPopulation growth, urban densification and climate change are increasing the water pollution and water shortage problems. To achieve more sustainable water management, wastewater reuse, both for non-potable and potable reuse purposes, appears to be an attractive option. In wastewater treatment and water reuse processes, oxidation treatment processes and membrane technologies are commonly applied by water utilities to remove recalcitrant contaminants and ensure the safety of the treated effluent. However, these processes are facing challenges including requirements of chemical reagents storage and transport, issues of membrane fouling and formation of toxic byproducts. Electrochemical technology presents a promising chemical-free approach with its potential to be applied in wastewater treatment and water reuse processes. This research aims to advance electrochemically assisted wastewater treatment and reuse processes, by developing chemical-free processes for oxidative wastewater treatment, understating the byproduct formation mechanisms, and proposing potential strategies for membrane fouling control and byproduct removal in wastewater reuse processes. A systematic literature analysis on byproduct formation and control in electrochemical oxidation revealed that wastewater parameters and types have significant effects of organic byproduct formation. The types of electrode materials such as nonactive and active would largely influence inorganic byproduct formation. Byproduct formation may be controlled through the optimization of key operating parameters. Using free chlorine quenchers and developing chlorine-inert anode would minimize byproduct formation. Post-treatment of byproducts such as electrochemical reduction or microbial reduction technology could also be applied. The degradation of organic contaminants and formation of byproducts were revealed in electrochemical oxidation treatment of phenolic wastewater. Multiple electrochemical cells were constructed to treat the recalcitrant wastewater. Formation of both the carbonaceous and nitrogenous byproducts were rigorously investigated through the electrochemical processes. Critical intermediates for byproduct formation and the potential byproduct formation pathways/mechanisms were identified and revealed. The effects of key water parameters and operating conditions were investigated. The removal and detoxification of halogenated byproducts by electrochemical reduction was elucidated in batch and continuous experiments. A granular activated carbon (GAC) – based cathode electrode was developed to enhance byproduct removal through integrated adsorption and reductive degradation. The analysis of degradation products demonstrated the detoxification of the byproducts via reductive dehalogenation. The continuous experiments indicated the consistent and sustainable byproduct treatment performance of the GAC-based cathode electrode. To achieve non-potable reuse of domestic wastewater, a microbial electrochemical system (MES) assisted UV/H2O2 process was developed. MES achieved organic compounds removal through bioanode degradation, while simultaneously generated H2O2 by the air diffusion cathode through oxygen reduction. The MES effluent containing H2O2 was further treated by an UV/H2O2 process to removal recalcitrant contaminants such as pharmaceuticals and personal care products (PPCPs) and pathogenic bacteria. The developed process achieved wastewater treatment without any chemical/water input, and the treated effluent meets the non-potable reuse guidelines of different countries. The feasibility of electrochemical softening and chlorination for potable reuse processes was tested in batch and continuous experiments using real secondary effluent. Through electrochemical processes, the OH--containing catholyte was used to achieve water softening through hardness precipitation. The H+- and chlor(am)ine-containing anolyte was applied to adjust pH and add disinfectants. Electrochemical treatment could help mitigate membrane fouling issues and supply disinfectants for water disinfection and distribution. This dissertation concludes with identifying future research opportunities in trade-off between contaminant removal and byproduct control in oxidation water treatment processes, scaling up of the lab scale systems and exploring more scenarios for application of electrochemically assisted water reuse systems, and utilizing renewable energy for the electrochemical techniques
The Physics and Chemistry of Phase Separation of Prion-like Low-complexity Protein Domains
Get PDFBiomolecular condensates are membraneless cellular compartments that arise via macromolecular phase separation. Condensates are involved in a variety of cellular functions, including trafficking, autophagy, ribosomal biogenesis, endocytosis, transcription, proteostasis, and stress response. In addition, condensates are associated with diverse pathologies, especially neurodegenerative and oncogenic processes. Given their physiological importance, much work has been done to characterize condensates via physical, chemical, and biological methods. It is now well-recognized that intrinsically disordered proteins (IDPs) are significant drivers of condensate formation. In particular, prion-like low-complexity domains (PLCDs), a subset of IDPs that share similar sequence compositions with yeast prion proteins, are often involved in cellular phase separation. While much work has been done to characterize the phase behaviors of PLCDs, there is still a lack of a comprehensive understanding of the sequence features that drive PLCD-based phase separation, as well as the microscopic and mesoscopic organizations of the resulting condensates. In this work, which is a highly collaborative effort among diverse scientists in the field of biomolecular condensates, we pursue a multi-pronged approach that brings together experimental, computational, and theoretical methods to understand the physics and chemistry that underlies PLCD-based phase separation. Our major discoveries result from a combination of phase separation assays, small-angle X-ray scattering experiments, analytical fitting and re-scaling procedures based on extant theories, systematic Monte Carlo simulations of IDPs, and a multitude of novel analyses that interrogate the interiors and interfaces of biomolecular condensates. Using these varied techniques, we first present FIREBALL, a computational toolkit that we developed to analyze measured phase separation data corresponding to various polymer systems, including IDPs and PLCDs. Next, we uncover a comprehensive set of rules that govern the driving forces for phase separation of PLCDs. We use these rules to develop a computational model of PLCD phase behavior that accurately recapitulates experimental data. Using this model, we find that the interiors of condensates are inhomogeneous network structures. Furthermore, PLCDs at condensate interfaces maintain fewer attractive interactions than other PLCDs in the system, are likely to adopt highly expanded conformations, and tend to be oriented perpendicular to the interface. Finally, we apply our model to multi-component systems of PLCDs to understand the effects of protein length and the interplay among homotypic and heterotypic interactions on phase behavior and condensate organization. The totality of our results provides a framework for understanding many recent findings, including that condensates are viscoelastic materials, that condensate interfaces appear to support unique biochemical reactions, and that certain molecules and ions prefer to accumulate on the inside or outside of condensates. Our results also set the stage to determine the precise scaling of the width of the two-phase regime as a function of temperature, to design multi-component condensates with multi-phasic architectures, and to understand the complex roles of condensate interfaces and how they relate to fibril formation associated with many PLCDs
A New Framework for Drug Pricing Law and Policy
Get PDFScholars and policymakers have expressed concern about the impact of high prescription drug costs on patients and healthcare budgets. This Article presents a new theoretical framework for evaluating both the problem to be addressed by drug pricing reforms as well as the efficacy of potential solutions. In seeking to solve “the drug pricing problem,” our legal system has given primacy to competition rather than regulation to drive down drug prices. This Article disaggregates the broader concept of “the drug pricing problem” into four steps, each of which must be addressed and each of which elevates different institutional actors to key roles. In the first step, approval, both new drugs and their competitors must receive approval from relevant regulators. In the second step, coverage, new drugs and their competitors must be covered by insurers. In the third step, prescription, physicians must prescribe a particular drug or its competitor. And in the fourth step, substitution, pharmacists must be able to substitute a lower-cost product for its branded version. Different areas of law — including health law, food and drug law, and patent law — and different institutional actors — including federal agencies, private insurers, physicians, pharmacies, and pharmaceutical companies — have distinct roles to play at each step of the framework. Identifying and describing each of these steps in terms of both the functions to be performed and the institutional actors performing them helps explain the existing structure of drug pricing law and policy. Some potential reforms might be incomplete in their scope, while other doctrines and institutional actors may have the ability to cut across steps, achieving greater impact. This Article categorizes drug pricing reforms according to the above-described steps, emphasizing policymakers’ focus on approval and substitution and more limited interest in coverage and prescription. Ultimately, this Article presents a series of legal and policy proposals to redirect reform efforts toward coverage and prescription, which may both more fully resolve existing legal bottlenecks and improve the efficacy of already-enacted reforms
Black Sonicism: Cultural Maintenance and Evolution through New Orleans Bounce Music
Get PDFAs a form of regional hip-hop, Bounce music operates as an expressive culture native to New Orleans with generational lineages of artists. Black sonicism is a regionally and digitally-sensitive theoretical framework that seeks to conceptualize how Black soundmakers and their audiences create a dialogic relationship through three components: responsive participation, spatial relatability, and expressed ratchetry. I catalog each of these components through three audience formations—origin, scope, and reception—to understand the tensions between Black music, regional identity, and technology. From this project, I propose a theoretical development to consider how Black artists continually pass down communal histories through their music while negotiating political and digital dynamics