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Effects of Nitrogen, Phosphorus and the Fungicide Azoxystrobin Additions on Larval and Post-Metamorphic Fitness of American Toads (Anaxyrus Americanus)
No full textSince European settlement, vast areas of U.S. land have been modified by humans. In the Midwest, an estimated 99% of native grasslands have been replaced by agriculture and urban development. Such alternations have replaced native habitat, redefined hydrology and introduced a wide array of chemicals into aquatic ecosystems. Modern agricultural practices utilize fertilizers and pesticides to maximize crop production. These chemicals frequently runoff into surrounding waters, potentially effecting aquatic organisms. One group of organism thought to be susceptible to agricultural contaminants are amphibians. Amphibians are vulnerable to pollution due, in part, to their permeable skin and biphasic life history. Global amphibian declines are well documented with over 40% of populations either in decline or facing extinction. To evaluate the short-term and long-term (legacy) effects of agricultural chemicals on amphibians, we utilized aquatic and terrestrial mesocosms and exposed American toads to three common contaminants (nitrogen, phosphorus, fungicide: azoxystrobin) in a fully crossed multi-factorial experimental design. We found that environmentally relevant concentrations of nitrogen and phosphorus decreased time to metamorphosis and increased size at metamorphosis. Azoxystrobin exposure had no effect on the metamorphic endpoint metrics. Toad mortality was very high (97%) in our terrestrial mesocosms across all treatments. We recommend further study into the short-term and long-term effects of common chemical combinations and their potential interactions with environmental conditions
Response of Benthic Macroinvertebrate Community Structure and Aquatic insect Secondary Production to Coarse Woody Debris Addition in Peri-Urban to Urban Golf Course Ponds
No full textGolf courses represent 29% and 26% of all greenspace areas in the U.S. urban regions and the Chicago metropolitan region, respectively; however, they are often overlooked among urban greenspaces as a tool to mitigate the impacts of increased urbanization on ecological communities. The primary aim of this research was to assess whether manipulating golf course pond habitats by adding coarse woody debris (CWD) would enhance aquatic invertebrate community structure and secondary production, with the potential to increase local biodiversity. One pond in each of six golf courses was selected for this study and sampled in summer 2020 before wood addition (Year 1) and summer 2021 after wood addition (Year 2). At the end of Year 1, CWD was added to three ponds, while three served as controls (no CWD addition). Benthic macroinvertebrate community structure and secondary production were evaluated each year to quantify changes associated with wood addition. Wood addition had no effect on any invertebrate taxa densities; however, there were significant effects on functional composition, i.e., functional feeding groups (FFGs) and functional habit groups (FHGs), and some diversity metrics. Shannon’s equitability, Inverse Simpson’s index of diversity, and Shannon’s diversity of many functional groups increased disproportionately more in wood-added (WA) ponds and either decreased or increased less than in no-wood added (NWA) ponds. There was a significant decrease in sprawler (FHG) richness in WA ponds and an increase in NWA ponds. Adding CWD to ponds did not affect aquatic insect secondary production at the taxonomic or functional level. Four of the 67 taxa collected accounted for 93% of the mean total secondary production across years and ponds. This lack of response is likely linked to an interaction between (1) low sample size, (2) many ponds with high macrophyte densities, which confounds the effect of CWD increasing detritus accumulation, and (3) newly added CWD in early stages of decomposition. Although results from this study suggest that wood in an early decay stage has limited effects on aquatic macroinvertebrate communities, they provide insight for future studies on using CWD addition as a habitat enhancement approach in golf courses, an understudied urban greenspace
Analyzing the Population Structure of the Rhizobia Associated with Astragalus Lentiginosus
No full textLegumes are an incredibly diverse and agriculturally important family of plants. They have a special relationship with symbiotic bacteria known as rhizobia which fix nitrogen into ammonia within nodules on their roots. Astragalus is the largest plant genus on Earth, and the species Astragalus lentiginosus is extraordinarily diverse, consisting of approximately 40 varieties. However, the rhizobia of A. lentiginosus have never been studied. In this study, root nodules were extracted from 17 varieties of A. lentiginosus to obtain rhizobial strains and metagenomes. A. lentiginosus primarily associates with rhizobia from the genera Mesorhizobium and Allomesorhizobium. There was little evidence of horizontal gene transfer of the symbiosis genes between the two genera. Rhizobia were more closely related based on host variety for Mesorhizobium or geographic distance for Allomesorhizobium. Several of these rhizobia belong to novel species, warranting further analysis and demonstrating the potential wealth of taxa hidden within wild legumes
The Role of Thioredoxin Reductase Paralogs in Prostate Cancer
No full textProstate cancer (PCa) is the second leading cause of cancer-related death in men. Early-stage PCa is treatable with androgen deprivation therapy (ADT) but resistance develops frequently, leading to castration-resistant PCa (CRPC). AR antagonists like enzalutamide are common therapies for CRPC, but late-stage disease is often fatal. Enzalutamide-resistant PCa exhibits high oxidative stress and upregulates antioxidant systems, notably the thioredoxin (Trx) system, which depends on ubiquitous thioredoxin reductases, TXNRD1 and TXNRD2. This cycle promotes survival by regulating transcription, proliferation, and apoptosis. TXNRD2 levels are higher in tumor tissue, suggesting patients may benefit from a TXNRD inhibitor. We identified a new class of non-covalent TXNRD inhibitors. siRNA knockdowns of TXNRD1 and TXNRD2 significantly reduced PCa cell viability. Two non-covalent inhibitors, 8VP101 and 9VP19, also decreased proliferation in vitro and synergized with enzalutamide to increase treatment efficacy. Ongoing studies aim to further characterize these compounds for potential therapeutic use in aggressive, late-stage PCa
The Economic Motivations Behind Climate Change Denial
Get PDFClimate change denial is often driven by economic interests, particularly among corporations that profit from industries reliant on fossil fuels. This can lead to companies spreading disinformation, casting doubt on what is considered a consensus by scientists worldwide. Disinformation is generated with the goal of preventing government regulations that could threaten their profits. By funding disinformation campaigns and lobbying against climate policies these corporations are steering the public discourse away from environmental issues and concerns. Understanding the economic motivations behind climate change denial is crucial in addressing misinformation and ensuring that policy decisions are guided by science rather than profit
The Concentration of Heavy Metals Within Bird Feathers of Neotropical Migrants Found on Loyola’s Lakeshore Campus
Get PDFThis presentation explores the relationship between heavy metal concentration in birds and migratory season. Over the course of three migration seasons, birds were collected from window strike fatalities across campus in collaboration with Student Operation for Avian Relief. Feathers from these individuals were tested using ICP-MS for their heavy metal load. They were tested for metals that are known to have adverse effects on avian health. Significant differences in metal loads were found between species, metal concentration and migratory season. The findings indicate similar testing could be done to identify potential metal pollution hot spots
Visit to Devon Gurdwara Sahib of Chicago
Get PDFFor a project for THEO 299, I conducted a study on Sikhism by visiting a local Sikh religious site. I chose to visit the Devon Gurdwara Sahib of Chicago, where I observed the practices of Sikhs and immersed myself in the culture and religion. I also conducted short interviews of 3 practitioners to learn more about their experiences
Constitutional Loopholes to Freedom: Information Control in China
Get PDFMy project, “Constitutional Loopholes to Freedom: Information Control in China,”explores how the leadership structure of China’s information control apparatus evolved from the Hu Jintao era to the Xi Jinping era—and what these shifts reveal about the Chinese Communist Party’s changing political priorities
Lucifer\u27s Monitoring of Circadian Clock Function in Fruit Flies
No full textThe circadian clock’s ~24 hour cycle functions to help an organism adapt its behavior and physiology for expected changes in the environment. The Drosophila fruit fly brain contains 150 clock neurons that each utilize a molecular circadian clock to maintain rhythmicity. We have created flies in which we can track molecular clock function through the use of luciferase, an enzyme used for bioluminescence in fireflies. We then utilized CRISPR-Cas9 gene editing to ablate the period gene in order to evaluate its role in circadian rhythmicity. Without the period transcription repressor, we expect to see loss of rhythmic expression of luciferase