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In the setting of an increasing incidence of endocarditis in the United States, we report a patient with necrotizing crescentic glomerulonephritis (GN) associated with native valve bacterial endocarditis due to Streptococcus parasanguinis. He was started on appropriate antibiotic treatment and subsequent blood cultures showed no growth. However, due to continuing decline in kidney function, immunosuppressive therapy was started. Despite immunosuppressive therapy and antibiotics, renal function did not improve and chronic hemodialysis was required. Due to rarity of condition, there are no definite treatment guidelines available. Antibiotics, steroids, immunosuppressive agents can be of help in most cases. Further research in this regard may help with early diagnosis and better treatment modalities.

This work investigates the modal properties of general cyclically symmetric systems and the multi-stage systems with cyclically symmetric stages. The work generalizes the modal properties of engineering applications, such as planetary gears, centrifugal pendulum vibration absorber (CPVA) systems, multi-stage planetary gears, etc., and provides methods to improve the computational efficiency to numerically solve the system modes when cyclically symmetric structures exist. Modal properties of cyclically symmetric systems with vibrating central components as three-dimensional rigid bodies are studied without any assumptions on the system matrix symmetries: asymmetric inertia matrix, damping, gyroscopic, and circulatory terms can be present. In the equation of motion of such a cyclically symmetric system, the matrix operators are proved to have properties related to the cyclic symmetry. These symmetry-related properties are used to prove the modal properties of general cyclically symmetric systems. Only three types of modes can exist: substructure modes, translational-tilting modes, and rotational-axial modes. Each mode type is characterized by specific central component modal deflections and substructure phase relations. Instead of solving the full eigenvalue problem,all vibration modes and natural frequencies can be obtained by solving smaller eigenvalue problems associated with each mode type. This computational advantage is dramatic for systems with many substructures or many degrees of freedom per substructure. Group theory is applied to further generalize the modal properties of cyclically symmetric systems when both rigid-body and compliant central components exist, such as planetary gears with an elastic continuum ring gear. The group theory for symmetry groups is introduced, and the group-theory-based modal analysis does not rely on any knowledge of the properties of system matrices in system equations of motion. The three types of modes (substructure modes, translational-tilting modes, and rotational-axial modes) are characterized by specific rigid-body central component modal defections, substructure phase relations, and nodal diameter components of compliant central components. The general formulation of reduced eigenvalue problems for each mode type is obtained through group-theory-based method, and it applies to discrete, continuous, or hybrid discrete-continuous cyclically symmetric systems. The group-theory-based modal analysis also applies to systems with other symmetry types. The group-theory-based modal analysis is generalized to analyze the multi-stage systems that are composed of symmetric stages coupled through the motions of rigid-body central components. The proposed group-theory-based modal analysis applies to multi-stage systems with cyclically symmetric stages, such as multi-stage planetary gears and CPVA systems with multiple groups of absorbers. The method also applies to multi-stage systems with component stages that have different types of symmetry. For a multi-stage system with symmetric stages, a unitary transformation matrix can be built through an algorithmic and computationally inexpensive procedure. The obtained unitary transformation matrix provides the foundation to analyze the modal properties based on the principles of group-theory-based modal analysis. For general multi-stage systems with symmetric component stages, the vibration modes are classified into two general types, single-stage substructure modes and overall modes, according to the non-zero modal deflections in each component stage. Reduced eigenvalue problems for each mode type are formulated to reduce the computational cost for eigensolutions. Finite element models of multi-stage bladed disk assemblies consist of multiple cyclically symmetric bladed disks that are coupled through the boundary nodes at the inter-stage interface. To improve the computational efficiency of calculating the full system modes, a numerical method is proposed by combination of the multi-stage cyclic symmetry reduction method and the subspace iteration method. Compared to the multi-stage cyclic symmetry reduction method, the proposed method improves the accuracy of obtained eigensolutions through an iterative process that is derived from the subspace iteration method. Based on the cyclic symmetry in each component stage of bladed disk, the proposed iterative method that can be performed using single stage sector models only, instead of using matrix operators for the full multi-stage bladed disks. Parallel computations can be performed in the proposed iterative method, and the computational speed for eigensolutions can be increased significantly. / Doctor of Philosophy / Cyclically symmetric structures exist in many engineering applications such as bladed disks, circular plates, planetary gears, centrifugal pendulum vibration absorbers (CPVA), etc. During steady operation, these cyclically symmetric systems are subjected to traveling wave dynamic loading. Component vibrations result in undesirable effects, including high cycle fatigue (HCF) failure, noise, performance reduction, etc. Knowledge of the modal properties of cyclically symmetric systems is helpful to analyze the system forced response and understand experimental modal testing. In this work, single stage cyclically symmetric systems are proved to have highly structured modes. The single stage systems considered in this work can have both rigid bodies and elastic continua as components. Group theory is used to study the modal properties, including the system mode types and the characteristics of different mode types. All the vibration modes of single stage cyclically symmetric systems can be solved from reduced eigenvalue problems. The methodology also applies to systems with other types of symmetry. For multi-stage systems with cyclically symmetric substructures, such as multi-stage planetary gears, a group-theory-based method is developed to analyze the modal properties. For industrial applications, such as multi-stage bladed disk assemblies, this work develops an iterative method to facilitate the calculations of system modes. The modal properties and methods for solving system modes apply to mechanical systems, including CPVA systems, the single/multi-stage planetary gears in power transmission systems, bladed disk assemblies in turbines, circular plates, elastic rings, etc.

In this research, Bayesian two-stage D-D optimal designs for mixture experiments with or without process variables under model uncertainty are developed. A Bayesian optimality criterion is used in the first stage to minimize the determinant of the posterior variances of the parameters. The second stage design is then generated according to an optimality procedure that collaborates with the improved model from first stage data. Our results show that the Bayesian two-stage D-D optimal design is more efficient than both the Bayesian one-stage D-optimal design and the non-Bayesian one-stage D-optimal design in most cases. We also use simulations to investigate the ratio between the sample sizes for two stages and to observe least sample size for the first stage. On the other hand, we discuss D-optimal second or higher order designs, and show that Ds-optimal designs are a reasonable alternative to D-optimal designs. / Ph. D.

Nonprofit organizations are pivotal actors in society, and their websites can play important roles in aiding organizations in their socially-beneficial missions by serving as a platform to present information, to interact with stakeholders and to perform online transactions. This dissertation analyzed nonprofit websites in the United States (U.S.) and in Thailand in a series of three articles. The first developed a website evaluative instrument, based on an e-commerce model, and applied it to nonprofit websites through a manual decoding process. That article's findings suggested that Thai websites are not considerably different than U.S. nonprofit websites, except more American websites offer online transactions. The second article analyzed two different types of nonprofits in Thailand using the same model to assess website development in an emerging market. That analysis suggested local Thai nonprofits' websites lagged significantly behind those of internationally connected nonprofit organizations in the country in the features they offered. The third article compared the adapted model employed in the second analysis, which used manual decoding for website examination, to a commercially available, automated evaluation service. That analysis highlighted the differences between the two assessment tools and found them to be complementary, but independently insufficient to ensure robust nonprofit website evaluation. / Ph. D.

Prolonged second stage of labor, excessive gestational weight gain and cesarean delivery has been associated with adverse maternal and fetal outcomes. Physical activity during pregnancy is a modifiable risk factor which has never been studied among Hispanic women. Gestational weight gain, another modifiable risk factor has only been evaluated as a risk factor for cesarean delivery in two studies among women induced for labor. To date, no study has examined the effect of duration of second stage of labor on intra-ventricular hemorrhage in very preterm births. We examined these maternal risk factors for prolonged second stage of labor, rate of cesarean delivery and fetal outcomes. The first study evaluated the association between physical activity and duration of second stage of labor. Prior studies regarding physical activity and duration of second stage of labor have been conflicting and none have examined the Hispanic population. During pregnancy, activities such as household chores, childcare, sports and women's occupation constitute a significant proportion of physical activity but have not been considered in prior studies. We examined the association between total physical activity (occupational, sport/exercise, household/care giving, and active living) during pre, early and mid-pregnancy and duration of second stage of labor in a prospective cohort of 1,231 Hispanic participants. Physical activity was quantified using the Kaiser Physical Activity Survey administered during pregnancy. Using multivariate linear regression we did not find statistically significant association between pre, early and mid-pregnancy physical activity and duration of second stage of labor. The second study focused on the effect of gestational weight gain on the cesarean delivery rate after induction of labor. The rate of induction of labor (IOL) has more than doubled from 9.5% in 1990 to 22.5% in 2006. Cesarean delivery usually follows a failed IOL and is associated with maternal and fetal morbidity. One of the two studies evaluating the effect of gestational weight gain on the rate of cesarean section in patients undergoing IOL was restricted to women with normal Body Mass Index (BMI) and the other was subjected to bias because more than half of the patients were missing BMI data. Therefore, we evaluated the effect of gestational weight gain on the rate of cesarean delivery after labor induction. In a retrospective cohort study design, using data from May 2005 to June 2008 and a multivariate logistic regression we found a 13% increase in risk of cesarean delivery with 5 kg increase in gestational weight gain. Finally, we evaluated the effect of mode of delivery and duration of second stage of labor on intra-ventricular hemorrhage (IVH) among early preterm births. IVH is a serious complication associated with preterm birth and important predictors of cerebral palsy and neurodevelopmental delays. Prior studies on this relationship in early preterm births are sparse. In a retrospective cohort study of newborns born less than 30 weeks or less than 1500 g between May 2003 and August 2008, we found an increase in risk of IVH after vaginal delivery. However, duration of second stage of labor had no significant effect on risk of IVH.

Robotic-assisted segmentectomy is a pulmonary resection procedure that is emerging as an alternative to lobectomy for the treatment of early-stage lung cancer tumours less than 2 cm in maximal diameter. Segmentectomy offers better lung function after surgery by only removing a few segments of the lobe that contain the tumour, and sparing remaining healthy lung tissue. As tumours are being more frequently detected in their early-stages, segmentectomy has gained considerable attention for its potential as a primary treatment option for suspected nodules less than 3 cm in maximal diameter. However, there is a reluctance in adopting segmentectomy due to technical challenges while performing the operation, and the lack of high-quality prospective data compared to lobectomy, which is the current standard of care. From a technical standpoint, segmentectomy is difficult to perform because the pulmonary lines that separate segments, or intersegmental planes, are invisible. This poses a challenge for the operating surgeon in determining where to resect the lung tissue to obtain adequate margin distance from the tumour. Near-infrared mapping (NIF) with indocyanine green dye (ICG) is a recent advancement in robotic-assisted segmentectomy that provides a complete delineation of the intersegmental plane. Previous work at our center has also shown that this technique was associated with an increase in the oncological margin distance compared to the surgeons’ initially estimated resection line. Given that segmentectomy is associated with a learning curve, we evaluated whether this was observed due to our early experience in robotic-assisted segmentectomy, and hypothesized that the added benefit of ICG would diminish as more cases were performed. In Chapter 2, we used a temporal analysis to monitor surgeon experience over time, and found that the clinical utility of NIF mapping diminished after approximately 42 cases with ICG, and the surgeon began to identify the location of the intersegmental plane more accurately and consistently without ICG injection since. The second barrier in the adoption of segmentectomy is the lack of high quality-prospective data. Current evidence pertaining to the effectiveness of segmentectomy in terms of cancer-related outcomes is inconclusive and difficult to generalize to the current lung cancer population. In Chapter 3, we performed a secondary analysis of a prospectively collected database of participants who underwent robotic-assisted segmentectomy or lobectomy for tumours less than 3 cm. The oncological efficacy of segmentectomy can be evaluated by the measuring the number of lymph node stations sampled intraoperatively and rates of nodal upstaging, and comparing these outcomes to pulmonary lobectomy. These are important surrogate outcomes that can be readily evaluated, and have been shown to predict overall survival after lung resection. We observed that these outcomes, including overall survival, were similar between patients who underwent segmentectomy and lobectomy for tumours less than 3 cm. While these findings were consistent for patients that underwent segmentectomy for tumours between 2 and 3 cm, recurrence-free survival was found to be significantly lower after segmentectomy compared to lobectomy. In conclusion, the clinical utility of near-infrared mapping diminishes over time, which is indicative of an improved ability to perform robotic-assisted segmentectomy as more cases were attempted. Second, adequate lymph node evaluation can be expected after segmentectomy, reducing the likelihood of missing positive lymph nodes. Although patients who underwent segmentectomy for tumours greater than 2 cm may be at a greater risk of experiencing recurrence compared to lobectomy, this population did not experience any reductions in overall survival. / Thesis / Master of Health Sciences (MSc)

<p> The thesis is concerned with the design, construction and evaluation of an analog to digital converter based on the "cascade" principle. However, this converter requires only one stage, instead of the usual one stage per bit required by conventional cascade converters. This reduction in the number of stages is achieved by storage in analog form, and by feeding the output of the stage back to its input via a switching network. An 8 bit converter that operates up to a clock frequency of 700KHz was built. The converter is shown to have promising possibilities as a low cost general purpose analog to digital converter. </p> / Thesis / Master of Engineering (MEngr)

Competition from hardwood species has long been considered a constraint on longleaf pine (Pinus palustris). However, evidence suggests that hardwood midstories may improve longleaf regeneration on xeric sites. Additionally, overstory retention for red-cockaded woodpecker (Leuconotopicus borealis; RCW) habitat may be inadvertently contributing to regeneration failures. Experimental plots in the North Carolina Sandhills were planted with containerized longleaf seedlings across a gradient of overstory density, and hardwoods were chemically controlled by treating at planting, treating after one year, or left untreated. Seedling survival (percent), growth (mass), and brown spot needle blight (percent infected seedlings; BSNB) were measured after two years. Seedling survival, growth, and BSNB infection rates were inversely related to overstory density. Midstory treatments did not significantly affect seedling survival, growth, or BSNB infection rates. Early results did not show facilitative effects from a hardwood midstory, but indicated overstory densities greater than 12 m2/ha negatively impact longleaf regeneration.

Inspired by my personal interest in the topic of dramaturgy, coupled with the continuous change programmes that Shell Oman Marketing Company (SOMC) adopts in many areas, this research attempts to explore the role of dramaturgy (Goffman 1956) in change management in SOMC. The primary question that this thesis addresses is: What is the role, impact and potential of dramaturgy in change management in SOMC? The objective is to examine the ability of dramaturgy to offer an effective method for managing change, and one that will eventually be used as an integral part of effective change management programmes in SOMC. The research consists of a case study of installing Closed Circuit Television (CCTV) system cameras in the offices of SOMC. The research was a qualitative study, conducting 22 semi-structured interviews along with unstructured observations of meetings and engagements. The research concludes that front stage performances and backstage performances are witnessed extensively in SOMC, and concludes that the boundary between front and backstage is blurred, that stories, metaphors and body language play an important role in performances, and that the audience perception of the authenticity, sincerity and genuineness of the performers is a key factor in their acceptance of the message. This research identifies a number of themes that can be added to the existing literature. The study highlighted the importance of ‘Alignment’ as a way of explaining the work that goes on in backstage and front stage performances, much part of living organisations. The term found extensively in organisational life at SOMC and many other organisations. Backstage meeting often has the goal of aligning participants to the message that has to be conveyed – the coordinated front stage performance. Therefore, alignment is a key element of the rehearsals and practices for the frontstage performances, and in bringing together the supporting team and loyalists. Another contribution of this research that is not available in other studies is that the importance of context and culture. That although metaphors and storytelling are used in many organisations across the world, they resonate particularly with Omanis because they are part of their history and culture. Hence using storytelling and metaphors in performances in SOMC can have a huge help connecting the audience with the performance.