Master of Science, The Ohio State University, 2023, Civil Engineering

Microcystins (MCs), a category of cyanotoxins produced by some species of the photosynthetic heterotrophic cyanobacteria, are the most studied, most associated with toxicity-related events, and most monitored in water. Water treatment plant (WTP) residuals are the solid byproduct of water treatment and consist of solids removed from physical and chemical processes and have been shown to contain cyanobacterial cells removed by conventional treatment processes. However, MCs in WTP residuals are not well understood. Although quantification methods of MCs for water samples have been adapted for solid matrices, their suitability for understanding the level of microcystins within a WTP residual sample is not well understood. Additionally, due to the inherent high variability within WTP residuals across the United States, these methods may not be optimal for every sample. Extraction and quantification methods were investigated to assess MCs in varied WTP residuals. Additionally, natural degradation observed in a utility's storage lagoon and was investigated to determine the impact of physical, chemical, and biological treatments on MC concentration in high-biomass residuals. This study demonstrates that residuals of various characteristics across the United States contain MCs, and that in some sample's extraction method (particularly methanol) and quantification method (particularly UPLC-PDA) increased measured MC, no single methodology is optimal for extracting and quantifying MCs across various residuals.

Committee: Natalie Hull (Advisor); Linda Weavers (Committee Member); John Lenhart (Committee Member) Subjects: Civil Engineering; Environmental Engineering; Environmental Science; Water Resource Management

Master of Science, The Ohio State University, 2020, Food Science and Technology

Color is a key factor affecting consumer's food choices. Artificial colorants have been used since the late 1800s, however, there is consumer and regulatory push to replace artificial colorants with naturally derived ones due to health and environmental reasons. Anthocyanins (ACN) are widely distributed pigments in plants that may act as antioxidants in the human body but have limited stability in foods. In aged red wines, ACN with a free hydroxyl group at C-5 condensate with a cofactor to form new 4-ring pigments called pyranoanthocyanins (PACN). Like ACN, PACN form naturally in nature and provide health benefits in the human body. They have an orange hue and are more stable than ACN but form slowly and inefficiently. The objective of this study was to produce PACNS faster and more efficiently using caffeic acid (CA) as cofactor and temperature as catalyzer. European elderberries (Sambucus nigra) containing cyanidin-derivatives with free hydroxyl group at C-5 were the ACN source. Elderberry powder was dissolved in water and anthocyanins were semi-purified using a C18 resin and concentrated. The monomeric anthocyanin concentration, measured by the pH differential method, was adjusted close to 25µM with 0.1M phosphoric acid buffer. CA, dissolved in 15% ethanol, was diluted with the buffer to achieve ACN-CA molar ratios of 1:50, 1:100, 1:150, and 1:200 and incubated at 65°C for 8 days. The effect of temperature was tested using a CA saturated ACN solution and incubating the samples at 25°C, 50°C, and 75°C for 4 days. Changes in composition were monitored using uHPLC coupled to PDA and MS/MS detectors. When different temperatures were compared at the same CA concentrations, samples incubated for 24 hr at 25°C had the most pigment remaining (98%). Samples held at 75°C for 72 hr degraded the most (only 30% left). Incubation at 75°C converted about 90% to PACN in 24 hours and about 100% to PACN in 48 hr. When samples of anthocyanin were incubated at the same temper (open full item for complete abstract)

Committee: M. Monica Giusti (Advisor); Jessica Cooperstone (Committee Member); Rafael Jimenez-Flores (Committee Member) Subjects: Food Science

Master of Science in Polymer Engineering, University of Akron, 2020, Polymer Science

Structural colors are typically produced by the interaction of light with sub-micron sized periodic structures. In nature, structural colors have been found in many species to serve multiple biological functions including sexual signaling, camouflage, and aposematism. Inspired by self-assembly of hollow melanosomes to produce brilliant structural colors in violet-backed starlings and wild turkeys, we set out to synthesize and assemble polydopamine (PDA)-based synthetic hollow melanin nanoparticles in an effort to fabricate structure colors. In this work, we designed hollow nanoparticles using polystyrene nanoparticle templates and then coated them with PDA layer of varying thickness. The polystyrene templates were subsequently removed by solvent etching using tetrahydrofuran (THF). The high refractive index (RI) contrast between the PDA (RI = ~1.74) shells and the air core (RI = ~1.00) enables the generation of bright and non-iridescent structural colors in the self-assembled structures of hollow nanoparticles created using the drop-casting process. With the use of only one ingredient (PDA), we successfully generate a wide spectrum of structural colors by simply controlling the core size and the thickness of the PDA shell.

Committee: Ali Dhinojwala (Advisor); Toshikazu Miyoshi (Committee Member) Subjects: Chemistry; Physical Chemistry

Doctor of Philosophy, The Ohio State University, 2016, Biomedical Sciences

The Notch signaling pathway has long been intricately linked with the development and function of the vasculature. In vascular smooth muscle cells (VSMCs), Notch signaling has a great influence on phenotype and is a strong promoter of differentiation and expression of contractile genes necessary to produce a functional vessel wall. However, the role of Notch signaling in VSMC proliferation and survival is less well defined, and some cases contradictory reports are given. Also, the contributions of each individual Notch receptor have not been clearly described. Thus, to better understand Notch signaling in VSMC phenotype, we investigated the specific roles of the predominant Notch receptors in VSMCs as they relate to differentiation, proliferation, and survival. We found that Notch3 promotes Platelet-Derived Growth Factor (PDGF)-induced proliferation in VSMCs, while Notch2 inhibits it. We also found that Notch3 was able to promote cell survival in response to apoptosis cues, while Notch2 had no discernible effect. Interestingly, we also found the expression of Notch2 and Notch3 were changed in response to proliferation and apoptosis inducers. Notch2 mRNA was significantly decreased after PDGF-BB treatment, a proliferation inducer, and Notch3 protein was degraded rapidly in response to induction of apoptosis. Additionally, we demonstrated that Notch3's induction of cell survival genes required MEK/ERK signaling and Notch3 was capable of increasing levels of phosphorylated ERK. Altogether, these findings demonstrate that Notch2 and Notch3 have unique functions in regulating VSMC phenotype. In a mouse model devoid of Notch2 and Notch3 in smooth muscle cells, we were able to show that Notch2 and Notch3 are required for normal closure of the ductus arteriosus. Animals without Notch2 in VSMCs presented with patent ductus arteriosus with increasing incidence combined with the loss of Notch3. These mice died within one day of birth and also presented with aortic dilation. (open full item for complete abstract)

Committee: Brenda Lilly PhD (Advisor); Joy Lincoln PhD (Committee Member); Andrea Doseff PhD (Committee Member); Aaron Trask PhD (Committee Member) Subjects: Biomedical Research; Cellular Biology; Developmental Biology; Molecular Biology

MS, University of Cincinnati, 2006, Allied Health Sciences : Nutrition

Background: Personal digital assistants, or PDAs, offer a promising piece of technology for patient care, teaching and research in the allied health professions. PDA use can improve efficiency, may prevent medical errors, and achieve better patient outcomes. The purpose of this study is to analyze and compare personal digital assistant (PDA) usage across four colleges at the University of Cincinnati. Methods: A mass email was sent in the fall of 2003 to 1,257 faculty and students of the College of Medicine, College of Nursing, College of Pharmacy, and College of Allied Health Sciences at the University of Cincinnati inviting them to participate in a web-based survey. Data from the surveys were downloaded to an Excel spreadsheet and analyzed using descriptive statistics. Results: Of the 1,257 individuals receiving the email request to participate in the survey, 317 individuals responded. 174 survey respondents, or fifty five percent, reported owning a PDA. The College of Medicine has the largest percentage of PDA owners at 65%. The most common uses of the PDA among owners were the address book, the calendar function, the calculations function and the memo pad. The least common uses were the medical records and patient tracking functions. When asked about their interest in PDA training, 38% of faculty and 29% of students owning a PDA would be interested in further training, while only 24% of non-PDA owners would be interested in receiving training on the usage and benefits of a PDA. Conclusion: Faculty and students of the four allied health colleges surveyed in this study do not appear to be using PDAs to their maximum benefit. Beyond the traditional common uses of the PDA (address book, calendar, calculations and memo pad functions), faculty and students are not accessing medical software programs available to them on a limited basis. A future extension of this study might investigate the effects of PDA training on increased PDA usage in a selected group of faculty a (open full item for complete abstract)

Committee: Shanil Juma (Advisor) Subjects: Health Sciences, Education

Doctor of Philosophy, The Ohio State University, 2008, City and Regional Planning

Researchers from many disciplines have examined neighborhood satisfaction. The research has focused more on the personal, social, and psychological dimensions than on the physical environment in relation to neighborhood satisfaction. When studies include physical characteristics, they tend to look at the perceived physical characteristics, possibly overlooking the impact of the physical environmental features on neighborhood satisfaction. Furthermore, while studies have identified physical attributes of environments related to “aesthetic” response, research has not examined the link between physical and judgmental ratings of those attributes, nor has it looked at the link between those measures and neighborhood satisfaction. This dissertation builds a conceptual model that focuses on the multi-level connections among the physical, perceptual, and evaluative measures of the neighborhood environment as determinants of overall neighborhood satisfaction. It uses on-line survey, on-site observations, and the combined satellite image processing and GIS spatial analysis. The survey asks residents to rate their perceptions and evaluations of the neighborhood environment, and then to rate their overall neighborhood satisfaction. 382 survey responses were collected in Franklin County, Ohio. Observations assess the conditions of the fixed and semi-fixed physical environmental elements on 2021 blocks. For observations, this study designed, used, and tested the neighborhood physical environment inventory (NPEI) instrument on a handheld Personal Digital Assistant (PDA). The Normalized Differential Vegetation Index (NDVI) method was combined with GIS spatial analysis. To assess both structural and measurement relations in a single model, this study uses a Structural Regression Model based on the two-step modeling process. The findings reveal the significant direct and indirect effects of physical, perceptual, and evaluative measures on neighborhood satisfaction. The results ext (open full item for complete abstract)

Committee: Jack L. Nasar PhD (Advisor); Jean-Michel Guldmann PhD (Committee Member); Hazel Morrow-Jones PhD (Committee Member) Subjects: Area Planning and Development; Urban Planning

Doctor of Philosophy, The Ohio State University, 2003, Welding Engineering

The characteristic relationship between cumulative plastic strains and angular distortion of fillet welded thin plate T-joints was studied using numerical analysis. A 3D thermo-elastic-plastic analysis incorporating the effects of moving heat and non-linear material properties was performed to obtain the characteristic cumulative plastic strain distributions and angular distortion. The procedure of plasticity-based distortion analysis (PDA) was developed to map each cumulative plastic strain component into elastic models using equivalent thermal strains. PDA determined the quantitative individual angular distortions induced by cumulative plastic strains, demonstrating their contribution to the total angular distortion and the unique relationship between cumulative plastic strains and distortion. PDA was used to investigate the effects of external restraints and thermal management techniques on the relationship between cumulative plastic strains and angular distortion of T-joints and T-tubular connections, and the limitation of the 2D model application in the distortion analysis of T-joints. It was shown that PDA was a very effective tool in investigating the relationship between cumulative plastic strains and distortion. The following significant findings were observed in this study. 1) Distortion was uniquely determined under the specified cumulative plastic strain distribution. 2) The transverse cumulative plastic strain produced bend-down angular distortion in T-joints. Vertical and longitudinal components induced relatively small bend-down and bend-up angular distortion, respectively. Most bend-up angular distortion produced by the xy-plane shear cumulative plastic strain existed in and around the welded region. 3) Angular distortion was reduced by increasing the degree of external restraint. External restraint mainly controlled individual angular distortion induced by the transverse cumulative plastic strain. 4) Heat sinking increased angular distortion of T-jo (open full item for complete abstract)

Committee: Chon Tsai (Advisor) Subjects: