Doctor of Philosophy, The Ohio State University, 2024, Entomology

Oyster mushrooms (Pleurotus spp.) are a highly nutritious mushroom genus favored for use in the fresh market and at fine dining restaurants. Furthermore, their nutrition is especially important for those who have food restrictions and for anyone eating a vegan diet as it provides most B vitamins, is high in protein by dry weight, and is one of the only non-animal sources of vitamin D when consumed. The oyster mushroom cultivation system is highly sustainable, utilizing agricultural byproducts such as mulch and straw, though many growers import inoculated substrate from China since the cost of sterilization equipment can be prohibitively expensive. The oyster mushroom is the second most produced mushroom in the world, with the United States production ranking second only to China. Pest management is important to produce a high-quality mushroom, but little information exists regarding the pest management of this mushroom species. Fungus gnats in the genus Lycoriella are one of the major pests for oyster mushroom production. The larvae cause direct damage of up to 30% crop loss through feeding on the mycelium. The adults cause indirect damage through vectoring green mold, Trichoderma spp., spores which can cause up to 100% crop loss. With such high potential for crop loss, the action threshold for this pest is 1 adult female per grow room and 1 larva per 125 g. To improve pest management on oyster mushrooms and to identify effective control strategies, four key questions were explored. Are there differences in infestation rates for fungus gnats in different species of oyster mushrooms? How effective are the current organic pesticide options for management of fungus gnats across different oyster mushroom species? What species of fungus gnat is present on oyster mushroom farms in the U.S. and what is the phenology of these infestations? To address the first question, two sets of bioassays were performed. The first (Chapter 2) was done with inoculated straw to deter (open full item for complete abstract)

Committee: Luis Canas (Advisor); Christopher Ranger (Committee Member); Reed Johnson (Committee Member); Sanja Ilic (Committee Member); William Hendrix (Committee Member); Andrew Michel (Committee Member) Subjects: Agriculture; Biology; Entomology; Genetics; Organismal Biology; Toxicology

Master of Arts, Miami University, 2021, Geography

The Pacific Golden Chanterelle (Cantharellus formosus) is a widely sought-after mushroom most abundant in the forests of Washington and Oregon, USA. This project used the species to investigate how accurately the species distribution could be modeled using natural history (herbarium) as model training data and citizen science (iNaturalist) as validation data. To combat the potential sampling bias towards population centers an effort variable weighting scheme was used to consider observations in harder to reach areas more than those in easier to access areas. Four models were created and run using the natural history data as training points: Random Forests (RF), Maxent, General Linear Model (GLM), and Artificial Neural Network (ANN); the effort variable was only applied to the ANN and GLM models. Out of these four, RF was found to perform the best with an equitable skill score (ETS) 0.987 when tested against the iNaturalist citizen science validation points. Overall, this project provides a good proof of concept and framework for the use of herbarium and citizen science data for use in biogeographical modeling projects in the future.

Committee: Mary Henry (Advisor); Jessica McCarty (Committee Member); Nicholas Money (Committee Member) Subjects: Geography

Master of Science in Biological Sciences, Youngstown State University, 2018, Department of Biological Sciences and Chemistry

The goal of this study was to examine the host cytokine response to a mutant strain (ΔyakA) of T. marneffei. T. marneffei is a fungus that causes the disease talaromycosis in AIDS patients. The fungus is dimorphic and switches between growth forms depending upon temperature. T. marneffei exhibits mold growth at 25°C but transforms into yeast cells inside of the host which become intracellular pathogens, living inside a variety of cells including macrophages. Previously, our laboratory discovered a mutant, designated ΔyakA. The protein encoded by the yakA gene is a type of molecular sensor. Studies showed that the ΔyakA mutant of T. marneffei has a weakened cell wall, which may affect its pathogenicity. Therefore, conidia of the ΔyakA mutant were co-cultured with the human monocyte cell line THP-1 or the macrophage-like murine cell line J774 to investigate whether the weakened cell wall has an effect on cytokine production, since cytokines play a vital role in host response to infection. The levels of the pro-inflammatory cytokines TNF-α , IL-1β and IL-6 were measured from cell lines infected with the ΔyakA and wild-type conidia. The THP-1 human macrophages produced significantly more IL-6 and TNF-α when co-cultured with WT compared with ΔyakA but IL-1β showed no significant difference. There were no significant differences in cytokines measured from J774 mouse macrophages exposed to WT versus mutant conidia. Although some differences were noted between cytokine levels of macrophages incubated with WT versus ΔyakA conidia, the differences were not uniform enough to presently conclude that the yakA gene affects host cytokine response.

Committee: Chester Cooper PhD (Advisor); Diana Fagan PhD (Committee Member); Gary Walker PhD (Committee Member); Jonathan Caguiat PhD (Committee Member) Subjects: Biology; Immunology; Microbiology; Pathology

PhD, University of Cincinnati, 2002, Medicine : Pathobiology and Molecular Medicine

Pneumocystis burden were associated with Pneumocystis fluctuations, suggesting that the competition was mediated by environmental factors. Microscopic analysis of rat lung sections showed that both species could exist in close apposition within the same alveoli, excluding habitat heterogeneity as a mechanism for coexistence. The immediate environment of the rat colony was surveyed for the presence of both species to find reservoirs of Pneumocystis, resulting in their identification from walls, floor, air vents, bedding, fur, and feces. Putative infective forms were isolated from air vents and oral cavities with P. carinii-specific antibody coated magnetic beads. These findings indicate that the immediate environment may harbor viable Pneumocystis. Differences between acquisition/transmission of both species were evaluated using targeted PCR of DNA from oral swabs, an ante mortem method developed to monitor P. carinii and P. ratti within the same rat. This technique could predict P. carinii infection outcome, but not P. ratti. Application of this technique showed that P. carinii could be acquired by neonatal rats within the first hour of life, but there was no evidence for vertical transmission of P. carinii by PCR analysis of fetal tissues. These studies suggested that Pneumocystis was acquired early in life. When P. carinii and P. ratti were present in the same lung, a competitive relationship occurred. Neither species was eliminated from the colony, suggesting coexistence. The competition interaction of the two species was likely influenced by environmental factors, suggesting such extrinsic conditions had an influence on the life cycle of these organisms.

Committee: Dr. Melanie T. Cushion (Advisor) Subjects: