Oxidative stress caused by the imbalance between antioxidants and oxidative species is a major component of several chronic diseases such as cardiovascular disease, cancer, and some neurodegenerative diseases. Potential therapeutics have previously been explored to address the role of oxidative stress in disease, but many have been unsuccessful or only target one aspect of this multifaceted disease pathway. To address this, Dr. Green’s lab at TCU created the L2 compound to act as a multimodal antioxidant therapy. Specifically, preliminary in vivo studies have demonstrated L2 can increase the cellular level of nuclear factor-erythroid 2-related factor (Nrf2), the natural antioxidant pathway of the cell. Normally this pathway is activated due to oxidative stress, allowing Nrf2 to migrate to the nucleus where it acts as an important transcription factor to produce antioxidant and detoxifying enzymes. This data was unexpected as the addition of antioxidant compound L2 should mitigate the need to activate the Nrf2 antioxidant pathway. Therefore, it is the purpose of this study to confirm that treatment of cells with L2 results in translocation of Nrf2 into the nucleus of cells. Further experiments will determine if this translocation leads to antioxidant effects as proposed.

Wind-energy production has expanded due to interest in increasing energy production and decreasing reliance on fossil fuels. Unfortunately, collisions and fatalities are unintended consequences of wind-energy production for many bat species. The Mexican free-tailed bat (Tadarida brasiliensis) has a non-migratory population in California that has an assumed sex ratio of 50:50, as seen in other nonmigratory bat species, and migratory sex-skewed (9:1 Female:Male) population in Texas that arrives in the summer to form maternal colonies. Knowing how males and females are impacted by collision mortality at wind turbines can provide insights into population-level effects. We determined the sex of bat carcasses discovered at wind turbines using DNA extracted from wing tissue samples collected during post-construction surveys in California (n = 502, 5 years) and Texas (n = 437, 3 years). Preliminary analysis of bats from California suggests that the sex ratio of fatalities did not differ significantly from 50:50 from 2016 to 2020 (p>0.05). In contrast in bats from Texas, the sex ratio of fatalities was significantly female-skewed in 2017 (6.8:3.2, z=3.25, p<0.001), became less female-skewed in 2018 (4.8:5.2) and 2021 (4.4:5.6), with neither 2018 nor 2021 being significantly different from 50:50 (p>0.05). This change in sex ratio in Texas might be demographically relevant if the loss of females from previous years is causing the migratory population to become less female-skewed over time. Studies of sex ratios at summer and winter colonies would allow determination of whether this same pattern is observed at the population level.

Oxidative stress is the imbalance between reactive oxygen species and antioxidants in a cell. Often this imbalance is caused by an increase of reactive oxygen species (ROS) leading to dyshomeostasis of the cellular redox balance. Oxidative stress is a major component of several chronic diseases including cardiovascular diseases, cancer and neurodegenerative diseases like Parkinson’s and Alzheimer’s diseases. To mitigate the damage caused by oxidative stress our cells are capable of producing their own antioxidants. One cellular mechanism involves the nuclear factor-erythroid 2-related factor (Nrf2) antioxidant pathway which can be activated in the presence of ROS. To better understand how this pathway works, it is important to track Nrf2 during activation of this pathway. Here we test three different plasmids designed to either force expression of “tagged” proteins in the Nrf2 pathway, or to provide a readout mechanism for the level of Nrf2 activation. These experiments lend support for the efficacy of using these tools to better understand the Nrf2 pathway.

The Thule Defense Zone in Northwest Greenland is a region of ecological concern because of its sensitive Arctic tundra ecosystem. Anthropogenic-induced climate change and deposition of contaminants into these fragile systems has the potential to alter these ecosystems. Mercury is a toxin of global importance that is capable of contaminating landscapes far from its source of origin, including those in the high Arctic. Understanding levels of mercury contamination that persist across landscapes requires analysis of aquatic ecosystems, as these systems are where mercury is converted into its toxic form, methylmercury. In Summer 2023, the Aquatic Ecology Lab at Texas Christian University will be traveling to the Thule Defense Zone and testing six ponds for mercury contamination. To better understand how contaminants reach these ponds, nutrient inputs from the landscape need to be understood. To date, there is no available watershed map for the Thule Defense Zone that delineates the hydrological characteristics of these ponds. My project will use Geographic Information Systems (GIS) to create a formal delineation of these aquatic systems.

Biodiversity, which is important to the function and stability of ecosystems, is currently being lost to extinction at an alarming rate. Thus, cataloguing and documenting the biodiversity of the world has never been more critical. In this study, the diversity and taxonomy of the tropical blueberries (Vaccinium L., Ericaceae) of Palawan and Mindanao Islands, Philippines were revisited. A total of 27 species (24 from Mindanao and four from Palawan) were documented and recorded. Six novel species, four new island records, and clarification of three ambiguous species complexes were included. Two of the six novel species (V. jubatum and V. vomicum) were discovered among historical herbarium collections, while the rest (V. carmesinum, V. coarctatum, V. fallax, and V. gamay) were discovered during botanical excursions. Two previously island endemic blueberries, V. cebuense and V. banksii, were documented to have an extended distribution in Mindanao. Additionally, V. irigaense is also recorded in Mindanao, whereas V. pseudocaudatum is recorded for the flora of Palawan. Further, the V. barandanum, V. caudatum, and V. halconense species complexes were taxonomically explained. The nomenclatural status of these species was stabilized through assigning type specimens following specifications of the International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code). We concluded that Mindanao Island is the center of Philippine Vaccinium diversity. This study underscores the crucial role of herbaria in understanding the floristic diversity of the world. This study also serves as a basis for taxonomical studies of the other blueberries in the Philippine Islands and Southeast Asia.