Master of Science, The Ohio State University, 2015, Mechanical Engineering

Mechanoluminescence (ML) is the emission of light from materials due to mechanical stimulation. Commercially available zinc sulfide phosphors exhibit intense ML during elastic deformations and are a natural fit for applications requiring repeatability and reliability. The motivation for this work is to utilize the intense ML of phosphors and fabricate a ML paint system. The ML paint system is envisioned to be sprayed on to automotive panels that are mechanically actuated to create patterned aesthetic lighting. Towards this goal, commercially available zinc sulfide phosphor crystals are characterized using experimental techniques to understand the dependence of ML on various physical and chemical properties. Composite coupons of the phosphors impregnated in an elastomeric polymer (PDMS) matrix have been fabricated for characterizing the ML phenomenon. The polymer matrix acts as an efficient medium for transferring stress to dispersed phosphor particulates. ML observed during elastic actuation of these coupons was studied to better understand the nature of the phenomenon, i.e. its dependence on strain/stress and rate of strain/stress. Existence of a threshold strain/stress has been established below which no EML is observed. Above threshold, EML was observed to be non-linearly dependent on and in phase with strain rate. Finite element analyses of the stress transfer occurring within the elastomeric matrix at various strains were also performed. A range stresses on the particle at different applied strains have been predicted and the importance of interfacial binding in stress transfer has been established.

Committee: Vishnu Baba Sundaresan Dr. (Advisor); Ahmet Kahraman Dr. (Committee Member) Subjects: Materials Science; Mechanical Engineering

Doctor of Philosophy, Miami University, 2021, Microbiology

Acinetobacter baumannii is Gram-negative bacterial human pathogen that can be found in myriad environmental niches and, more notoriously, thrives in the hospital setting. This opportunistic pathogen is the causative agent in a range of disease outcomes including wound infections, urinary tract infections, meningitis, and pneumonia. The ability of A. baumannii to persist on medical equipment in the hospital environment, colonize the human host, and express a number of antibiotic resistance mechanisms makes it a formidable nosocomial threat and justifies the investigation of the molecular mechanisms underlying its virulence and overall physiology. A. baumannii uses various sensing and regulatory systems to coordinate a response to cues from its local environment. Of particular importance in the context of this study are the cues of light and temperature. The goal of the work presented in this manuscript was to elucidate the molecular mechanisms underlying light sensing and regulation in A. baumannii at two different temperatures, 24°C and 37°C. The dependence of the bacterial oxidative stress response on the blue light using flavin protein BlsA at 24°C was tested using catalase activity, peroxide resistance, and superoxide dismutase (SOD) assays. BlsA's regulation of the catalase enzyme KatE was dependent on the BlsA residue lysine 144, and its regulation of SOD activity was dependent on the last five BlsA residues. Blue light-dependent, BlsAindependent regulation at 24°C was examined by RNA sequencing analysis and investigation of the role of the putative photolyase PhrB in light-dependent functions. Global blue light-dependent transcriptional regulation was apparent even in the absence of BlsA at 24°C. Furthermore, PhrB did not play a detectable role in canonical photolyase activity yet did impact bacterial surface-associated motility, a light-regulated phenotype in A. baumannii. For bacteria cultured at 37°C, a temperature at which BlsA is not (open full item for complete abstract)

Committee: Luis Actis PhD (Advisor); Kelly Abshire PhD (Committee Member); Mitchell Balish PhD (Committee Member); Rick Page PhD (Committee Member); Timothy Wilson PhD (Committee Member) Subjects: Microbiology

MARCH, University of Cincinnati, 2017, Design, Architecture, Art and Planning: Architecture

Stress is a major issue in healthcare design. There is a growing recognition that stress can play a vital role in patient's outcome. Many healthcare facilities suffer from absence of adequate spaces which can be psychologically supportive and complementary to the healing process of patients. These kinds of spaces do not encourage health, and often times they are the reason for the stress among patients as well as visitors and staff. The focus of this research would be to first define the environmental design issues in healthcare facilities, , which influence patients outcome, based on the researches done on evidence-based design (EBD), and then try to find a set of design considerations that implication of which can potentially solve these issues, and improve patients as well as visitors and staff experience. The designed building is a brain and spinal cord injury rehabilitation center. The site of the building is located in San Diego, California, in the north of University of California. The site is located on top of the cliff and is overlooking to Pacific Ocean on the west. Torrey pines park is on the north-east of the site. Unique location of the site provides plenty of uninterrupted scenic vistas and panoramic views throughout the site. Offering outside views, bringing in abundant of natural light, and integrating outdoor spaces and greenery in the form of courtyards, balconies, and terraces were some of the major strategies used in the design of the rehab center. Moreover, there was a particular emphasis in creating environments which can provide an adequate balance between private and social life of the patients. The concept of the prospect/refugee has been explored and widely implemented in the design of the building. Circulation has become a key design element. A component which bridges between private and public. An element which brings transparency by creating a connection between indoor and outdoor spaces, and all in all enhance the experience of (open full item for complete abstract)

Committee: Aarati| Kanekar| Ph.D. (Committee Chair); Ann Black Ph.D. (Committee Member) Subjects: Architecture

Doctor of Philosophy (PhD), Ohio University, 2013, Chemistry and Biochemistry (Arts and Sciences)

NF-κB is a transcription factor that controls expression of genes involved in the immune and inflammatory responses as well a being a key component in the onset of cancers. In this study we provided evidence that MSK1 is responsible for a non-canonical late-phase activation of NF-κB upon UVB irradiation. Our data demonstrated that following UV irradiation, MSK1 is activated via phosphorylation at the 24 h time point coinciding with translocation of NF-κB into the nucleus. Investigations into the signaling pathways upstream of MSK1 through the use of specific inhibitors for mitogen-activated protein kinase and p38 revealed that both kinases are required for full phosphorylation during the late-phase (24 h), while p38 is paramount for phosphorylation during the early-phase (6 h). Electromobilty shift assays (EMSA) showed that inhibition of MSK1 resulted in a marked reduction in NF-κB binding affinity without altering the nuclear translocation of NF-κB. Supershift EMSA implicate that the p65, but not p50, isoform of NF-κB is involved in late-phase activation in response to UVB irradiation. Together, the results of these studies shed light onto a novel pathway of MSK1 mediated late-phase activation of NF-κB in response to UV irradiation. Exposure to UV induces a prolonged expression of COX-2 via transcriptional activation that is due in part to an increase in NF-κB activity. While transcriptional regulation of COX-2 expression has been well studied, the role of translational regulation of COX-2 synthesis upon UV-irradiation is not yet clear. In this study, we show that the phosphorylation of the alpha subunit of eIF2α plays an important role in the regulation of COX-2 expression after UV-irradiation. Our data demonstrates that UV light induces COX-2 expression in wild-type mouse embryo fibroblasts (MEFS/S) and that the inducibility is reduced in MEFA/A cells in which the phosphorylation site, Ser-51 in eIF2α, is replaced with a nonphosphorylatable Ala (S51A). UV (open full item for complete abstract)

Committee: Shiyong Wu PhD (Advisor) Subjects: Biochemistry; Cellular Biology; Molecular Biology; Oncology

Doctor of Philosophy, The Ohio State University, 2007, Integrated Biomedical Science

Non-melanoma skin cancer is the most prevalent form of cancer. The incidence of basal cell carcinoma is 2X higher and squamous cell carcinoma is 3X higher in males compared to females. Exposure to UVB is the primary agent responsible for the formation of NMSCs. While it is well documented that males spend more time out in the sun and use less sun protective measures, the potential of a biological contribution to these gender differences had not been previously evaluated. We therefore investigated the gender differences in the acute UVB induced inflammatory response and chronic UVB induced tumor formation in the hairless Skh-1 mouse model. Our studies demonstrated that acute exposure to UVB induced a cutaneous inflammatory response in both the male and female mice, however, the response was markedly lower in the males. After chronic exposure to UVB, the male mice exhibited enhanced carcinogenesis as they developed tumors earlier, developed more tumors, and developed larger tumors. Overall males had twice the tumor burden and more aggressive tumors. Interestingly, with the limited inflammatory response, the males exhibited elevated oxidative DNA damage and a limited antioxidant capacity allowing for more oxidative stress induced DNA damage. There is evidence that estrogen may convey a protective effect on the female gender. Topical estrogen decreased the acute inflammatory response in the female mice, yet enhanced the response in the males. Estrogen enhanced tumor multiplicity and tumor burden in the female mice, however, the tumors in both genders were less aggressive. Topical treatment with Faslodex, a complete anti-estrogen, increased tumor size in both genders and the tumors were more aggressive. Due to the gender differences in baseline antioxidant capacity, we examined the activity of catalase, glutathione peroxidase, glutathione reductase and glutathione s-transferase in the skin. These studies demonstrated that multiple enzymes contribute to the baseline diffe (open full item for complete abstract)

Committee: Tatiana Oberyszyn (Advisor) Subjects:

Master of Science, Miami University, 2012, Zoology

The immune system is critical to an animal's survival. However, changes in immune function during insect development, and the factors that regulate these changes, are not well understood. Hemocytes carry out cellular defenses such as phagocytosis, nodulation, and encapsulation of pathogens. The enzyme phenoloxidase (PO) plays a key role in this process while the enzyme lysozyme breaks down bacterial cell walls. Total PO (TPA) and lysozyme activities, total blood hemocytes, and encapsulation ability were examined from late nymphal stages through early adulthood in the cricket, Acheta domesticus. TPA increased with age while encapsulation ability tended to decrease. The effects of crowding and light stress during nymphal development on adult immune parameters were determined. Crowding increased TPA in crickets housed in small but not large groups. Light stress negatively impacted survival, but not immune function. Further investigation of the effects of early life stress on adult immune function is thus warranted.

Committee: Kathleen A. Killian PhD (Advisor); Nancy G. Solomon PhD (Committee Member); Ann L. Rypstra PhD (Committee Member) Subjects: