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Ecology of Beech Leaf Disease: Identifying the Forest Conditions Correlated with Infection in Northeast Ohio
No full textBeech Leaf Disease (BLD) is a novel, poorly-understood threat to forests across North America. Since its discovery in northeast Ohio in 2012, the disease has affected staggering numbers of beech trees (Fagus grandifolia), resulting in increased sapling mortality. In the near future, mortality in symptomatic mature trees is expected to follow. The symptomatic striped leaves result from the activity of the nematode Litylenchus crenatae ssp. mccannii, but the precise role this organism plays in transmission and infection is currently unknown.
Oberlin College has been conducting forest demography research at Chance Creek, a nature preserve in Lorain county, since 1974. Every tree has been identified, recorded, and measured in plots across the 67 acre park, with data from 1974, 1986, 1998, 2015, and 2024. This timeline includes a previous tree epidemic, the Emerald Ash Borer, which provides valuable insight into how forest demography changes following such disturbances. While our 2024 dataset includes the first measures of BLD at Chance Creek, we are collaborating with researchers at the Holden Arboretum to compare similar datasets collected on forests closer to the epicenter of this disease to make inferences across larger regions.
We are analyzing these combined datasets to identify ecological conditions that may help or hinder BLD, such as localized community composition, tree species diversity and density. By learning which ecological variables affect BLD transmission, we may be able to predict, mitigate and prevent future infections of BLD and outbreaks of similar tree diseases across the country
Development of a divergent synthesis of N-methylene-substituted saccharin-based inhibitors for rhomboid intramembrane proteases
No full textRhomboid intramembrane proteases represent a subclass of serine hydrolases with membrane-embedded active sites. These proteins participate in critical cellular processes, such as mitochondrial quality control and growth factor signaling, though their physiological functions are still not fully understood. In addition, their abnormal activity has been linked to several diseases, including multiple types of cancer. Small-molecule competitive inhibitors have served as important chemical tools for studying and characterizing proteins. These inhibitors can be utilized to selectively target proteins of interest to investigate their activity in biological systems and provide insight into potential strategies for treating diseases. This work presents the divergent synthesis and testing of N-methylene-substituted saccharin-based structures as small-molecule mechanism-based inhibitors for rhomboid intramembrane proteases. The synthetic route involves a three-step sequence to convert simple halo-substituted o-toluenesulfonyl chlorides into C3-C6 halo-substituted saccharins. After N-acyloxymethylation of these saccharins, Suzuki-Miyaura and Sonogashira cross-coupling reactions provide access to a range of alkyl, alkynyl, and aryl substituents in the C3-C6 positions. The influence of these different substituents on the inhibition of the rhomboid proteases has been investigated using a competitive activity-based protein profiling (ABPP) strategy. Testing of the N-methylene-substituted saccharin-based inhibitors against PARL and RHBDL4, two human rhomboid proteases, has revealed that selective inhibition is possible. Continued development of these structures may enable the discovery of potent and selective rhomboid protease inhibitors in the future
Effect of L-arabinose on internal and external pH of PHL628 Escherichia coli
No full textUnderstanding how environmental sugars influence intracellular pH (pHi) is crucial, as pHi homeostasis can be impacted through biofilm formation in Escherichia coli. Biofilms—structured communities of bacteria attached to surfaces—protect the cells from environmental stressors, including desiccation and exposure to antibiotics. Altered pHi regulation within biofilms may be able to affect bacterial metabolism, stress response pathways, and even the efficacy of antibiotics. In this project, we examined whether the presence of L-arabinose, a common pentose, affects the pHi of E. coli. Our previous transcriptomic data for PHL628 biofilm and planktonic cells in the presence of arabinose showed the activation of pH-responsive stress pathways and efflux pumps, among other changes to metabolic pathways. This protocol enables us to compare intracellular acidification in arabinose-treated and untreated cells. It provides insights into the role of araE, an arabinose symporter, in pH regulation and the metabolic response to L-arabinose. Our findings shed light on how E. coli adjusts its pHi under varying environmental conditions, with implications for biofilm formation and antibiotic resistance
Bulls and Barrels: Gendered Identities in Contemporary American Rodeo
No full textRodeo sports are often thought of as a relic of American culture that has endured the passage of time. Despite rodeo’s reputation as one of the most authentic forms of American sport, little is known about contemporary rodeo culture from a sociological perspective. And although gender in sport has received extensive scholarly attention in recent years, even less is known about the gendered experiences of modern rodeo athletes. This paper investigates the meaning of gendered identities in rodeo culture, focusing specifically on the sport’s most popular men’s and women’s events: bull riding and barrel racing, respectively. In-depth interviews with nine rodeo athletes, combined with ethnographic data gathered from both professional and amateur rodeos, reveal the complicated meaning of the terms “cowboy” and “cowgirl” in the sport’s contemporary construction. Pierre Bourdeiu’s theory of cultural capital and Carrie Paechter’s theory of masculinities and femininities as communities of practice are applied to account for the multiplicity of gendered identities present in rodeo. From these theoretical perspectives, cowboy-ness and cowgirl-ness can be interpreted as localized gender performances intimately related to, but not entirely dependent upon, the actual practice of rodeo sports. Athletes’ relationships with animals, occupations, and lifestyles outside of rodeo all influence their relationships to cowboy-ness and cowgirl-ness. Studying gender from this localized perspective reveals the imperfect and socially-variable nature of the reproduction of gender hegemony. While they are often thought to be ubiquitous within American society, these findings suggest that hegemonic forms of gender expression are culturally variable
Investigating Carbon and Oxygen Dynamics in Lake Erie: A Machine Learning Approach to Analyzing Seasonal and Interannual Drivers
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