INTRODUCTION: The implementation of open posterior component separation (PCS) surgery has led to improved outcomes for complex hernias. While the PCS technique has been shown to decrease recurrence rates, and provide a feasible option to repair hernias in nontraditional locations, there is still significant postoperative pain associated with the laparotomy and extensive abdominal wall manipulation. Systemic opioids and thoracic epidural analgesia (TEA) are both commonly utilized, either together or independently, as postoperative analgesic regimens. The benefits of TEA have been studied following a variety of surgeries, however to date no study has been performed to investigate its efficacy in this particular surgery. The aim of this study is to evaluate the benefits of TEA following open PCS. We hypothesized that the incorporation of TEA in a patients postoperative analgesic regimen would show an advantage in time to bowel recovery. METHODS: An electronic medical record query was done to identify patients who had undergone an open PCS. Once this list was compiled, a retrospective chart review was performed and patients receiving TEA (either alone or combined with systemic opioids) were compared to patients receiving only systemic opioids. The primary endpoint compared time to resumption of a full diet, given by the patients postoperative day (POD). Secondarily, time to resumption of a liquid diet, postoperative length of stay (LOS), intensive care unit (ICU) admission rate, ICU LOS, and rates of several postoperative complications were all recorded and compared. A post-hoc analysis was also performed using the same endpoints. This analysis compared cohorts of patients receiving TEA and avoiding all systemic opioids, to patients who received systemic opioids (whether alone or combined with TEA). RESULTS: Based on inclusion parameters, 101 patients met criteria for analysis. In the initial analysis, 62 patients received TEA with or without systemic opioids, and 39 patients received only systemic opioids. In comparing these groups, there was no statistically significant difference in time to full diet (TEA 2.6 ± 1.7 vs Systemic opioids 3.1 ± 2.1 [mean POD ± SD]; P=0.21). In addition, no differences were found in the secondary outcomes of time to liquid diet, ICU admission, ICU LOS, or postoperative complications. In the post-hoc analysis, the 37 patients that received only TEA, were compared against 64 patients that received systemic opioids (either with or without TEA). In this comparison, the group receiving only TEA was found to have a statically shorter time to bowel recovery compared to patients receiving systemic opioids (TEA alone 2.2 ± 1.0 vs Systemic opioids 3.2 ± 2.2, P=0.0033). This subgroup (TEA only) also showed statically shorter time to liquid diet and a decreased postoperative LOS. CONCLUSION: For patients undergoing an open PCS, the inclusion of TEA in the postoperative analgesic regimen did not shorten return of bowel function. However, when TEA was utilized and systemic opioids were avoided, time to bowel recovery and hospital LOS were both significantly shortened.

Tornado outbreaks have significant human impact, so it is imperative forecasts of these phenomena are accurate. As a synoptic setup lays the foundation for a forecast, synoptic-scale aspects of Storm Prediction Center (SPC) outbreak forecasts of varying accuracy were assessed. The percentages of the number of tornado outbreaks within SPC 10% tornado probability polygons were calculated. False alarm events were separately considered. The outbreaks were separated into quartiles using a point-in-polygon algorithm. Statistical composite fields were created to represent the synoptic conditions of these groups and facilitate comparison. Overall, temperature advection had the greatest differences between the groups. Additionally, there were significant differences in the jet streak strengths and amounts of vertical wind shear. The events forecasted with low accuracy consisted of the weakest synoptic-scale setups. These results suggest it is possible that events with weak synoptic setups should be regarded as areas of concern by tornado outbreak forecasters.

Optical flow and its extensions have been widely used in motion detection and computer vision. In the study, principal component analysis (PCA) is applied to analyze optical flows for better motion detection performance. The joint optical flow and PCA approach can efficiently detect moving objects and suppress small turbulence. It is effective in both static and dynamic background. It is particularly useful for motion detection from outdoor videos with low quality and small moving objects. Experimental results demonstrate that this approach outperforms other existing methods by extracting the moving objects more completely with lower false alarms. Saving strategies are developed to reduce computational complexity of optical flow calculation and PCA. Graphic processing unit (GPU)-based parallel implementation is developed, which shows excellent speed up performance.

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In the face of global climate change, all disciplines and backgrounds have a responsibility to the shared future. The world is facing an impending environmental disaster and humanity’s current efforts are not enough to slow this change, let alone reverse it. Much more drastic efforts must be undertaken by every person and discipline. Architecture has both aesthetic and structural components that have contributed to this situation. Much like the rest of the world, the current practices of architecture are not responsive or responsible enough. The building sector has a unique role in national and global energy consumption. Not only are the structures that are created by these assorted professions responsible for consuming large amounts of annual energy, but the very materials used in their construction add millions of tons of waste to landfills each year. The building sector should not just be responsible for the long-term effects of a structure during the construction and demolition phases. Architecture’s and other design professions’ responsibilities should not end with the completion of a project. Rather, all of the choices, designs, and decisions made before, during, and after the project will echo through the ages as the structure lives on, long after the building has been occupied. There are many possible solutions to this conundrum, ranging from passive techniques to complex technologies. The incorporation of biological design into modern construction is explored in this thesis. This paper investigates the implications of current building materials in comparison to the potential of an organically informed alternative created from mycelium, the root network of fungi, and post-industrial waste. This thesis considers laboratory experiments and case studies in architecture to understand the shortcomings and potentials of organically derived structures and building materials. Original observations are undertaken to understand the effect of a mycelium composite’s design on various physical properties. This project seeks to evaluate the building blocks of architecture and reevaluate the building field from the ground up. Small individual components are assessed, and their long-term implications are explored.

<p> Inflatable structures have attracted much interest in space applications. The three main components of inflatable satellites are inflatable struts, an inflatable torus as the structural support component, and some sort of lens, aperture, or array housed inside the boundary of the torus. This project is devoted towards understanding the dynamic characteristics of an inflated torus with a focus on the self-rigidizing torus, SRT, developed by United Applied Technologies.</p> <p> The self-rigidizing torus is manufactured from flat sheets of Kapton® that are formed into curved films with the regular pattern of hexagonal domes. The inflated torus can support its structural shape even when there is no internal pressure.</p> <p> Modal testing is used to determine the dynamic properties of the structure for comparison with the numerical model. The feasibility of using a non-contact in-house fabricated electromagnetic excitation is investigated. The first four, in-plane and out-of-plane, damped natural frequencies and their corresponding damping ratios and modes shapes are extracted and compared with prior experimental studies. A preliminary finite element modal analysis is carried out for a torus made of flat film and the results are compared with prior studies. Kapton 300JP®'s frequency-dependent modulus of elasticity is determined.</p> <p> Owing to the large number of hexagonal domes in the self-rigidizing torus, a simplified sub-structuring technique is used. Each hexagonal dome is replaced with a statically equivalent flat hexagon with the same mass and stiffness as the hexagonal dome. Then the finite element modal analysis of the self-rigidizing torus is carried out for an equivalent torus made of flat film. The geometric nonlinearity and the effect of the follower load on the stiffness are included in this analysis. The methodology is verified through the correlation between the analytical and modal test results of the self-rigidizing torus.</p> / Thesis / Doctor of Philosophy (PhD)

Arrow's Impossibility Theorem outlines the flaws that effect any voting system that attempts to order a set of objects. For its entire history, American college football has been determining its champion based on a voting system. Much of the literature has dealt with why the voting system used is problematic, but there does not appear to be a large collection of work done to create a better, mathematical process. More generally, the inadequacies of ranking in football are a manifestation of the problem of ranking a set of objects. Herein, principal component analysis is used as a tool to provide a solution for the problem, in the context of American college football. To show its value, rankings based on principal component analysis are compared against the rankings used in American college football. / Thesis / Master of Science (MSc) / The problem of ranking is a ubiquitous problem, appearing everywhere from Google to ballot boxes. One of the more notable areas where this problem arises is in awarding the championship in American college football. This paper explains why this problem exists in American college football, and presents a bias-free mathematical solution that is compared against how American college football awards their championship.

There has been an exponential increase in satellite image data availability. Image data are now collected with different spatial, spectral, and temporal resolutions. Image fusion techniques are used extensively to combine different images having complementary information into one single composite. The fused image has rich information that will improve the performance of image analysis algorithms. Pansharpening is a pixel level fusion technique used to increase the spatial resolution of the multispectral image using spatial information from the high resolution panchromatic image while preserving the spectral information in the multispectral image. Resolution merge, image integration, and multisensor data fusion are some of the equivalent terms used for pansharpening. Pansharpening techniques are applied for enhancing certain features not visible in either of the single data alone, change detection using temporal data sets, improving geometric correction, and enhancing classification. Various pansharpening algorithms are available in the literature, and some have been incorporated in commercial remote sensing software packages such as ERDAS Imagine® and ENVI®. The performance of these algorithms varies both spectrally and spatially. Hence evaluation of the spectral and spatial quality of the pansharpened images using objective quality metrics is necessary. In this thesis, quantitative metrics for evaluating the quality of pansharpened images have been developed. For this study, the Intensity-Hue-Saturation (IHS) based sharpening, Brovey sharpening, Principal Component Analysis (PCA) based sharpening and a Wavelet-based sharpening method is used.

Chemotaxis is the ability of an organism to sense its environment and move towards attractants and away from repellents. The two-component system controlling chemotaxis in bacteria contains a histidine kinase CheA, which is autophosphorylated in response to a signal from a ligand-bound transmembrane methyl-accepting chemotaxis protein. CheA transfers the phosphate group to its cognate response regulator which modulates flagellar rotation. Signal termination by dephosphorylation of the response regulator is necessary for the organism to react rapidly to changes in the environment. The phosphorylated response regulator CheY in <i>Escherichia coli</i> is dephosphorylated by CheZ, a phosphatase; certain organisms, such as <i>Sinorhizobium meliloti</i>, that lack a CheZ homolog have developed alternate methods of signal termination. The signaling chain of S. meliloti contains two response regulators, CheY1 and CheY2, in which CheY2 modulates flagellar rotation and CheY1 causes signal termination by acting as a phosphate sink. In addition to known chemotaxis components, the second gene in the chemotaxis operon of <i>S. meliloti</i> codes a 97 amino acid protein, called CheS. The phenotype of a cheS deletion strain is similar to that of a cheY1 deletion strain. Therefore, the possibility that CheS causes signal termination was explored in this work. The derived amino acid sequence of CheS showed similarities with its orthologs from other °-proteobacteria. Sequence conservation was highest at the centrally located °4 and °5 helices. Earlier observations that CheS localizes at the polar chemotaxis cluster in a CheA-dependent manner were confirmed, and the co-localization of CheS with CheA was demonstrated by fluorescence microscopy. The stable expression of CheS in the presence of CheA was confirmed by immunoblot. The same approach was used to establish the stable expression of CheS only in the presence of the P2 domain of CheA, but not with the P1 or P345 domains. Limited proteolysis followed by mass spectrometry defined CheA_163-256 as the CheS binding domain, and this domain overlapped the previously defined CheY2-binding domain, CheA_174-316. The role of CheS in the phosphate flux in S. meliloti chemotaxis was analyzed by assays using radio-labeled [?-?°P]ATP. CheS does not play a role in the autophosphorylation of CheA. However, CheS accelerated the rate of CheY1~P dephosphorylation by almost two-fold, but did not affect the rate of CheY2~P dephosphorylation. CheS also does not seem to affect phosphate flow in the retrophosphorylation from CheY2~P to CheA using acetyl [?°P]phosphate as phosphodonor. Since CheS increases the rate of CheY1 dephosphorylation, it can be envisioned that it either increases the association of CheY1 to CheA, increasing the flow of phosphate from CheA to CheY1, or directly accelerates the dephosphorylation of CheY1~P. The presence of a STAS domain and a conserved serine residue in CheS also raises the possibility that CheS may be phosphorylated by a yet unknown kinase, in a mechanism similar to the phosphorylation of <i>Bacillus subtilis</i> SpoIIAA by its cognate kinase SpoIIAB. Phosphorylated CheS may then switch CheA between a kinase or phosphotransferase ON/OFF state or activated CheS may directly interact with CheY1. Further studies are needed to determine the association of CheY1 with CheS to elucidate the mechanism of CheY1 dephosphorylation. This work has confirmed the <i>in vitro</i> association of CheS with CheA, determined the CheS binding domain on CheA, and indicated that CheS accelerates the dephosphorylation of CheY1~P. This has advanced our understanding of the role of CheS in the chemotaxis signaling chain of <i>S. meliloti</i>. / Master of Science

A study was conducted to examine the correlation between a novel behavior monitoring system and a validated data logger. We concluded that the behavior monitoring system was valid for tracking daily rest time in dairy cows (R=0.96); however the correlation values for rest bouts and rest duration were relatively low, (R=0.64) (R=0.47), respectively. Daily monitoring of animal activity and milk components can be used to detect mastitis prior to clinical onset. Data from 268 cases with clinical mastitis and respective controls (n=268) from Virginia Tech and the University of Florida dairy herds were examined. Variables collected included daily milk yield, electrical conductivity, milk fat, protein, and lactose percent, as well as activity measurements including daily rest time, daily rest duration, daily rest bouts, and daily steps taken. Variables were collected for case and control cows in the 14 d prior to and after clinical diagnosis, for a total 29 d monitoring period. A milk sample was aseptically collected upon detection of clinical signs as observed by milker's at both farms. A statistical method (candisc discriminant analysis) was used to combine all measurements and sensitivity and specificity was calculated. Virginia Tech cows on d -1 (sensitivity=95%, specificity=95%), Virginia Tech and University of Florida cows on d -1 (sensitivity=88%, specificity=90). Overall, daily monitoring of animal activity and milk components can detect mastitis prior to onset of clinical signs of disease. This may allow producers to intervene and make proactive management decisions regarding herd health prior to clinical diagnosis. / Master of Science