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- Creators: School of Life Sciences
In Photosystem II of plants, the proton motive force that is essential for life is generated partly by the water oxidation process where the tyrosine and histidine 190 (hydrogen bonded) amino acids play an important role. The proton-coupled electron transfer (PCET) process involving these two molecules has been replicated using a benzimidazole-phenol (BIP) construct as an artificial model of both the intramolecular hydrogen bond interaction and the associated PCET process. BIP is a nearly planar molecule and features a strong intramolecular hydrogen bond between the phenol and the nitrogen of the benzimidazole. When the molecule is oxidized electrochemically, the phenolic proton is transferred to the nitrogen of the benzimidazole moiety in a PCET mechanism. Herein the design, synthesis, and physicochemical characterization of a new BIP derivative is described. By introducing a methyl group in the new design, we intentionally increase the dihedral angle between the benzimidazole and phenol rings. The presence of the methyl group affects the ground-state PCET and the excited-state intramolecular proton transfer processes as well. The break in the coplanarity weakens the strength of the intramolecular hydrogen bond, decreases the chemical reversibility, and quenches the emission from the excited-state intramolecular proton transfer state. The findings contribute to understanding the importance of having a nearly planar structure in bioinspired artificial photosynthetic systems.
Insects are able to navigate their environments because they can detect hydrocarbons and volatile odors, but it is not clear which one has the fastest reaction when detected, or how much of a response can be produced due to either one. In order to determine which category of odorant is detected first as well as which one causes the highest response rate, data on electrophysiological responses from ants was analyzed. While the statistical tests can be done to understand and answer the questions raised by the study, there are various hydrocarbons and volatile odors that were not used in the data. Conclusive evidence only applies to the odorants used in the experiments.
In order to determine whether the spatial organization of FRCs and their expression of maturation markers (such as Ltbr) are altered with age, I performed immunofluorescence on frozen and cryosectioned whole lymph nodes from young and aged mice. My second aim was to perform RT-qPCR and flow cytometry in order to determine whether FRCs from aged mice have altered expression of maturation markers when compared to young mice. Thus, the goal of the honors thesis research was to determine whether lymph node FRCs in the aged mouse exhibit signs of impaired maturation in their protein and gene expression. As the immune system is profoundly impacted by aging, my project supports a cellular mechanism by which defects in aged tissues disrupt immune cell function. Therefore, understanding the age-associated decline in host defense could provide new avenues for the treatment of many diseases of which the elderly are most vulnerable, in particular re-emerging and novel pathological agents such as COVID-19.
Every day, the earth’s oceans are being destroyed. Pollution, fishing, sonar, and many other man-made factors have caused detrimental effects to the most crucial of the ocean’s ecosystems. While more individuals are becoming aware of these problems, additional support is needed to help protect the ocean’s many unique creatures. The purpose of this honors thesis exhibition is to continue to shine light on human negligence towards threatened ocean creatures. The three artworks in this thesis show the descent of diversity and life of these marine creatures over time. By showcasing the different ways in which whales, rays, and corals have been affected by human impact, this thesis and subsequent art pieces will help to continue to enhance one’s understanding of the importance of marine conservation.