2018 UMKC Theses - Freely Available Online
Permanent URI for this collection
Browse
Recent Submissions
Item Development of Resistance to Antifungal Agents in Common Yeast Species(2018) Shreeve, Jacob Parker; White, Theodore C.Pathogenic fungi are responsible for several serious diseases in both plants and animals with severe consequences in both medicine and agriculture. This makes treatment of fungal infections a prime concern for both economic and humanitarian concerns. Treatment for pathogenic fungus infections is hindered by the lack of development of new drugs that inhibit growth of fungi, as well as the mechanisms by which fungi develop resistance to existing drugs. The development of new antifungal drugs is slow and requires a great deal of testing to ensure the drug is both safe and effective. It is therefore important that current drugs are used in a manner to prevent the development of resistance phenotypes. The growing number of pathogenic yeast infections has resulted in the greater use of antifungal drugs in patient treatment. With this increase in use, several strains have arisen with resistance to commonly used antifungal agents such as azoles and polyenes. Therefore, the characterization and study of mechanisms of drug resistance is of the utmost concern. The purpose of this study was to characterize how several species respond to drug challenge as well as the mechanisms guiding their responses. ABC transporters are known for increasing drug resistance phenotype through increased efflux of drugs from the cell. In this thesis, two studies have been performed to examine the ways in which the expression of ABC transporters may lead to drug resistance. First, a commercially-available Saccharomyces cerevisiae strain exhibiting an azole resistance phenotype was determined to possess an overexpression of PDR5. Subsequently that strain was deleted of the efflux pump PDR5 and examined for the loss of the azole resistance phenotype. The resulting deletion strain exhibited a decrease in all drugs but retained some resistance to fluconazole and ketoconazole. Second, several putative ABC efflux transporters from Aspergillus fumigatus (AF) were heterologously expressed in a hyper-susceptible S. cerevisiae strain. The resulting strains exhibited differences in substrate specificity efflux that may shape the treatment of AF strains that express these transporters. Third, the further study of pathogenic yeasts was facilitated by the development of a table of Minimum Inhibitory Concentration (MIC) values for several common species against a variety of drugs and media. This table was created with the intent of provide basal MIC values in response to common environmental conditions to reduce time needed to establish testing conditions and basic growth conditions for the listed species.Item Biomass Burning and Its Relationship with Water Cycle Dynamics of the Chari-Logone Catchment of Lake Chad Basin(University of Missouri -- Kansas City, 2018) Black, Forrest; Lee, JejungThe present study investigates the effect of biomass burning on the water cycle dynamics of the Chari-Logone catchment, which is the primary water source of Lake Chad, in central sub-Saharn Africa, providing approximately 95% of surface water inflow to the lake. A significant challenge in calculating water balance for this region is the lack of meteorological station data and the low temporal frequency of sampling by the few existing stations. WetSpass-M, a monthly water balance model, was chosen for this study due to its ability to calculate water balance without the large amount of data that many other models require. Satellite observations from TRMM, MODIS, and SRTM, and other earth science missions provide well distributed data at reasonable spatial scales. For a more comprehensive look at the effects of burning, i.e. albedo change, which has been shown to have a significant impact on a number of environmental factors, was considered when calculating potential evapotranspiration as a model input. Two water balance simulations, one considering burning and one without, were compared from the years 2003 to 2011. A groundwater model was also built using Processing MODFLOW, using actual evapotranspiration from both burning and non-burning water balance outputs. The resulting calculated runoff from the model agreed well with ground observations, with a Nashe-Sutcliffe Efficiency of 0.57. Seasonal analysis shows a correlation between water-cycle parameters and burning, and is affected by the region's seasonal variability, where burning increases during the dry season and decreases during the wet season. The groundwater model performed well for dry season months when there was less rainfall. However, when wet season evapotranspiration (ET) was used, the model over exaggerated the groundwater levels. This was most likely due to the way the groundwater and evapotranspiration parameters are handled in WetSpass-M. When the primary land cover types were studied (grass, savanna, and cropland); all three land cover types showed a significant reduction in ET. This is shown by average wet season ET decreasing -5.E+13 m³per month and a decrease 7.E+13 m³for the dry season months. This lends support to the hypothesis that with increased burning, there is a decrease in certain hydrologic parameters including precipitation.Item Plasma-Enhanced Atomic Layer Deposition of Boron Carbide for Interconnect Applications(University of Missouri -- Kansas City, 2018) Dorsett, Lauren Mikal; Paquette, Michelle M.As the semiconductor industry endeavors to scale integrated circuit dimensions— decreasing layer thicknesses while increasing the aspect ratio of fillable features—the need for novel interconnect materials with highly specialized properties continues to rise. Meeting the requirements for the numerous types of materials needed, including low-k dielectrics, etch stops, metal diffusion barriers, hardmasks, spacer layers, and other pattern-assist layers, with traditional silicon-based materials is becoming increasingly challenging. As an alternative to silicon, amorphous hydrogenated boron carbide (aBC:H), grown through plasma-enhanced chemical vapor deposition (PECVD), has been demonstrated to possess excellent dielectric properties, combined with very high Young’s modulus, electrical properties rivaling those of SiOC:H variants, very good chemical stability, and unique and useful etch chemistry. However, a problem with PECVD growth that will limit its long-term utility is its inability to scale while maintaining uniform, conformal coatings for very thin films. To combat the issues arising from PECVD grown boron carbide, a plasmaenhanced molecular-layer-deposition-based process for the growth of BC films on metal (copper) substrates using solid carborane precursors was proposed. This thesis describes the design and construction of a reactor chamber capable of this hypothesized film growth as well as the characterization of those preliminary depositions. Monolayer carborane growths on copper substrates were demonstrated with characterization including in situ spectroscopic ellipsometry, as well as ex situ contact angle analysis and X-ray photoelectron spectroscopy. The surface of the monolayer was then plasma treated and preliminary multi-layer growths were testedItem Association of Nasal Septum Area and Deviation with Anteroposterior Maxillary Position and Facial Skeletal Asymmetries(University of Missouri -- Kansas City, 2018) Kaiser, Kevin; Venugopalan, Shankar RengasamyDuring growth of the craniofacial structure, the nasal septum is posited to exert a downward and forward effect on the midface. This phenomena is well documented in vitro and on animals but is still uncertain in humans. This study examined the nasal septum association with craniofacial structures using cone-beam computed tomography (CBCT) of human subjects. First, cartilaginous nasal septum area was tested for association with anteroposterior position of the maxilla. The area of the cartilaginous nasal septum was calculated using the CBCT scan and a lateral cephalometric radiograph was created from the CBCT to evaluate the anteroposterior position of the maxilla. Second, nasal septum deviation was tested for association with frontal skeletal asymmetry. The absolute septal deviation (ASD) was calculated in the frontal plane where most deviated and a frontal cephalometric radiograph was created from the CBCT to evaluate for skeletal asymmetry. Nasal septum area and anteroposterior position of the maxilla were not associated (bivariate regression analysis, p>0.05). Nasal septum area was significantly associated (p<0.05) with lower gonial angle, total anterior face height, upper face height, lower face height. Subsequently, a model was created to assess nasal septum area with cranial base measurements association on the maxillary, mandibular, and maxillo-mandibular measurements (multivariate stepwise regression). This showed a significant association (p<0.05) in females for SNA (R²=23.80%), total maxillary length (R²=60.80%), and Wits (R²=14.20%). In males, the model association was significant with total maxillary length (R²=35.20%), SNB (R²=31.40%), and ANB (R²=40.00%). ASD and skeletal asymmetries were split into right and left deviations and tested for association with right and left measurements, respectively. Right side ASDs had statistically significant (p<0.05) correlations with right facial width, right mandibular width, and right occlusal plane. No measurements were significantly associated with left side ASDs and left side measurements. Though we were unable to test the causal relationship of the nasal septum with facial growth, our results suggest that the nasal septal cartilage may exert a downward force and has minimal forward influence on the midface in humans. It also suggests that a deviated nasal septum may influence the asymmetry of the facial skeleton.Item Hand Gesture Recognition via Electromyographic (EMG) Armband for CAD Software CONTROL(University of Missouri -- Kansas City, 2018) Nabulsi, Ala-Addin; Derakhshani, RezaIn the past, computers - whether personal or at work - required a mouse and key board to interact with them, and they are still used to this day. Even for video games a physical tool (controller) is needed to interact with the gaming environment. Previously that was acceptable since that was how these electronic devices were conceived, but with the recent boom in Virtual reality (VR) and Augmented Reality (AR), that reality has already started to change. VR and AR have existed for well over 2 decades [1], yet only in the last 5 years have they started getting closer to reaching their true potential. With this new technology, we can go to virtual worlds, interact with creatures that never previously existed, and visualize information in ways never thought possible before. With the emergence of VR came the need to change the way we interact with the virtual environment and, with that, the way we interact with technology as a whole. And what better controller for the job than the human hand. If the user can interact with technology with hand gestures then the whole process becomes intuitive, eliminating any training time, and giving the user a more natural experience. For this, Hand Gesture Recognition (HGR) systems will be needed. HGR systems recognize the user’s hand shape by means of a glove, cameras, or biosignals. One particularly useful biosignal for this task is the forearm Electromyographic (EMG) Signal. This signal reflects the contraction state of the forearm muscles. EMG signals are already being used in prosthetics to help amputees have more natural control over their prosthetic limbs. They can also be used for translating sign language, or just generally in Human-Machine-Interaction (HMI). This work proposes a method to interact with computers using hand gestures, specifically for a Computer Aided Design (CAD) software known as Solidworks. To achieve this a commercial EMG armband (the Myo - Thalmic Labs) was used to record 8-channel EMG signals from a group of volunteers over the span of 3 visits. The data set was then preprocessed and segmented. The resulting data set consisted of 10 hand gestures performed by 10 subjects, with 162 samples per gesture. A total of 11 feature sets were extracted and applied to 4 different machine learning models. A 9-fold cross validation and testing was performed and the classifiers over all the feature sets were evaluated and compared. The best model validation performance was achieved by the Linear Discriminant Analysis (LDA) model with an average Area Under Curve (AUC) of 76.35% and an average Equal Error Rate (EER) of 29.73% In future work, we propose to use the HGR method developed in this thesis in multiple applications such as mapping certain shortcut commands in Solidworks (and other applications) to hand gestures.