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Self-ligating brackets, including molar buccal tubes, have gained popularity in recent decades. The primary advantage of using self-ligating systems has been based on the claim that they provide reduced friction and therefore reduced sliding resistance of the arch wire contained within their respective slots.1 This form of reduced friction and sliding resistance has been proposed to require less force and therefore produce more physiologic tooth movements.7-9 Limited scientific evidence is currently available to establish quality control of these products. The purpose of this study is to use Micro Computed Tomography (MicroCT) to analyze self-ligating molar tubes manufactured by different companies. Methods used here provide a novel way for measuring the accuracy and quality of these materials. This study has provided a highly innovative approach that had not been previously accomplished. Forty self-ligating lower left first mandibular molar samples were obtained from four different companies. Five samples from each company were randomly selected and scanned using MicroCT to determine the internal slot lumen of each tube for analysis of precision volumetric measurements. Additionally, qualitative analysis of the lumen of each tube was investigated for the presence of any internal slot defects or imperfections. Results showed that the volumetric slot measurements of all samples were highly statistically significant (P<0.001) and were found to be oversized compared to what is claimed by their respective companies. Qualitative analysis of all samples illustrated varying defects contained within their respective internal slot lumens. Notable defects included notched, beveled and irregular corners, as well as the presence of some bulbous metal projections. Based upon the results obtained in this study, it was determined that the investigated self-ligating buccal tubes, produced by all the companies tested, were oversized and had various internal slot defects. The potential clinical significance of these dimensional inaccuracies may include an increased amount of friction and a lack of torque control during tooth movement. / Oral Biology

Discrete Trial Teaching (DTT) is a teaching method that involves fast-paced trials designed to teach basic skills by breaking them into smaller components, typically conducted in a one-on-one setting. Treatment integrity has proven to be of great importance in DTT, with skill acquisition occurring at higher rates when treatment integrity is high. While research has shown that verbal and written feedback are effective in training staff to conduct DTT, there is still a need for research on the use of individualized interventions based on performance assessments. This study used a multiple-probe across participants design, and demonstrated that a one-on-one session including interventions such as feedback, practice, treatment integrity checklists, and/or antecedent interventions is an effective method for increasing treatment integrity and implementation of DTT. The three participants that took part in the individualized interventions all displayed increases in proficiency of delivering DTT trials. / Applied Behavioral Analysis

Maintaining genomic integrity is important for any organism. DNA mismatch repair (MMR) serves to correct errors that occur during DNA replication and recombination, such as unpaired bases or mismatched bases. Mutl is a key player and serves to coordinate protein-protein interactions. Recently it has been shown that human Mutl functions as an endonuclease and that this activity is imperative for functioning MMR. In this work, the X-ray crystal structure of the C-terminal endonuclease domain of Bacillus subtilis Mutl (BsMutL-CTD) is presented. Diffraction quality crystals of BsMutL-CTD were grown using vapor diffusion. The crystal structure of BsMutL-CTD was solved using multiwavelength anomalous diffraction. The structure reveals a putative metal binding site which clusters closely in space with endonuclease motif. Using the structure and sequence homology, several mutations were made and an investigation into the endonuclease activity of BsMutL was performed. BsMutL was confirmed to be a manganese-dependent endonuclease and key residues which contribute to endonuclease function were identified. / Thesis / Master of Science (MSc)

This is the report of a Delphi study designed to identify the characteristics, behaviors, and work environments of spiritual leaders. A panel of philosophers, writers, business leaders, non-profit leaders, religious leaders, educators, and politicians was purposefully recruited to participate in the study. Data gathered from the panel were analyzed with the Maykut and Morehouse (1994) constant comparative method and descriptive statistics to identify characteristics, behaviors, and work environments of spiritual leaders. The panel-identified characteristics and behaviors of spiritual leaders were grouped into three themes: interpersonal, intrapersonal, and religious. Work environments in which spiritual leaders can be effective were grouped into six themes: community-building, person-centered, product-oriented, principle-driven, religious, and mission/purpose-driven. The interpersonal descriptors are predominant in the findings, supporting the conclusion that spiritual leadership is interpersonal in nature in an enhanced way. Although writers have emphasized that spiritual leadership is separable from religion, the panelists accepted 13 descriptors in religious categories, indicating that they had difficulty separating spiritual religious leadership from a secular counterpart. The findings incorporate the concepts of meaning, community, and integrity presented in a theory of spiritual leadership created for this study, but the findings go well beyond the concepts in the theory. To be more reflective of reality, the theory must be expanded to emphasize the other-orientation of spiritual leaders. The expanded theory and the enriched concepts within it may have benefit to practitioners and future researchers interested in exploring the practice and study of spiritual leadership. Two tools were created from the findings. One tool is a self-assessment that leaders may use to compare their leadership style with that of spiritual leaders. The second tool may be used by leaders to assess whether their work environments promote the effectiveness of spiritual leaders. Researchers may find the tools useful as initial measures of the characteristics, behaviors, and environments of spiritual leaders. / Ph. D.

Safety risk evaluation is critical in autonomous vehicle applications. This research aims to develop, implement, and validate new safety monitoring methods for navigation in Global Navigation Satellite System (GNSS)-denied environments. The methods quantify uncertainty in sensors and algorithms that exploit the complementary properties of light detection and ranging (LiDAR) and inertial measuring units (IMU). This dissertation describes the following four contributions. First, we focus on sensor augmentation for landmark-based localization. We develop new IMU/LiDAR integration methods that guarantee a bound on the integrity risk, which is the probability that the navigation error exceeds predefined acceptability limits. IMU data improves LiDAR position and orientation (pose) prediction and LiDAR limits the IMU error drift over time. In addition, LiDAR return-light intensity measurements improve landmarks recognition. As compared to using the sensors individually, tightly-coupled IMU/LiDAR not only increases pose estimation accuracy but also reduces the risk of incorrectly associating perceived features with mapped landmarks. Second, we consider algorithm improvements. We derive and analyze a new data association method that provides a tight bound on the risk of incorrect association for LiDAR feature-based localization. The new data association criterion uses projections of the extended Kalman filter's (EKF) innovation vector rather than more conventional innovation vector norms. This method decreases the integrity risk by improving our ability to predict the risk of incorrect association. Third, we depart from landmark-based approaches. We develop a spherical grid-based localization method that leverages quantization theory to bound navigation uncertainty. This method is integrated with an iterative EKF to establish an analytical bound on the vehicle's pose estimation error. Unlike landmark-based localization which requires feature extraction and data association, this method uses the entire LiDAR point cloud and is robust to extraction and association failures. Fourth, to validate these methods, we designed and built two testbeds for indoor and outdoor experiments. The indoor testbed includes a sensor platform installed on a rover moving on a figure-eight track in a controlled lab environment. The repeated figure-eight trajectory provides empirical pose estimation error distributions that can directly be compared with analytical error bounds. The outdoor testbed required another set of navigation sensors for reference truth trajectory generation. Sensors were mounted on a car to validate our algorithms in a realistic automotive driving environment. / Doctor of Philosophy / Advances in computing and sensing technologies have enabled large scale demonstrations of autonomous vehicle operations including pilot programs for self-driving cars on public roads. However, a key question that has yet to be answered is about how safe these vehicles really are. "Autonomously" driving millions of miles (with a trained safety driver taking over control to prevent potential collisions) is insufficient to prove fatality rates matching human performance, i.e., lower than 1 per 100,000,000 miles driven. The safety of an autonomous vehicle depends on the safety of its individual subsystems, components, connected infrastructure, etc. In this research, we evaluate the safety of the navigation subsystem which uses sensor information to determine the vehicle's location and orientation. We focus on light detection and ranging (LiDAR)and inertial measuring units (IMU). A LiDAR provides a point cloud representation of the environment by measuring distances to surrounding objects using beams of infrared light (laser beams) sent at regular angular intervals. An IMU measures the acceleration and angular velocity of the vehicle. We assume that a map of the environment is available. In the first part of this research, we extract recognizable objects from the LiDAR point cloud and match them with those in the map: this process helps estimate the vehicle's position and orientation. We identify the process' limitations that include incorrectly matching sensed and mapped landmarks. We develop new methods to quantify their impacts on localization errors, which we then reduce by incorporating additional IMU data. In the second part of this dissertation, we design and evaluate a new approach specifically aimed at provably increasing confidence in landmark matching, thereby improving vehicle navigation safety. Third, instead of isolating individual landmarks, we use the LiDAR point cloud as a whole and match it directly with the map. The challenge with this approach was in efficiently and accurately quantifying the confidence that can be placed in the vehicle's navigation solution. We tested these navigation methods using experimental data collected in a controlled lab environment and in a real-world scenario.

This dissertation introduces Power Fingerprinting (PFP), a novel technique for assessing the execution integrity of embedded devices. A PFP monitor is an external device that captures the dynamic power consumption of a processor using fine-grained measurements at the clock-cycle level and applies anomaly detection techniques to determine whether the integrity of the system has been compromised. PFP uses a set of trusted signatures from the target code that are extracted during a pre-characterization process. PFP provides significant visibility into the internal execution status, making it extremely robust against evasion. Because of its independence and physical separation, PFP prevents attacks on the monitor itself and introduces minimal overhead on platforms with resource constraints. Due to its anomaly detection operation, PFP is effective against unknown (zero-day) attacks. This dissertation demonstrates the feasibility of PFP on different platforms with different configurations and architectural complexities. Experimental results demonstrate the feasibility of PFP in a basic deterministic embedded platform for radio applications in two different areas: security and regulatory certification. For more complex, non-deterministic platforms, this works presents feasibility results for monitoring the execution integrity of complex software on a high-performance Android platform, including the ability to detect a real privilege escalation attack. In addition, the dissertation develops several general techniques to implement and integrate PFP into embedded platforms such as a general monitoring architecture, a methodology to characterize software modules and extract signatures, and an approach to perform board characterization and improve monitoring sensitivity. / Ph. D.

Benthic macroinvertebrate communities in headwater streams influenced by Appalachian coal mining often differ from communities in minimally distrubed streams. Total dissolved solids (TDS) associated with mining have been suggested as stressors to these communities. In studies of such streams conducted to date, both non-TDS stressors and elevated TDS have been present as potential influences on biota. Here the association between dissolved salts and benthic macroinvertebrate community structure was examined using a family-level multimetric index and genus-level taxa sensitivity distributions. Test sites were selected along a gradient of elevated TDS, with non-TDS factors of reference quality. Virginia Stream Condition Index (VASCI) scores were regressed against log-transformed measures of TDS, specific conductance, and sulfate (SO42-) using ordinary least squares and quantile regression techniques. Biological effects, as defined by VASCI scores indicating stressed or severely stressed conditions, were observed with increasing probability from 0% at ≤ 190 mg/L TDS to 100% at ≥ 1,108 mg/L TDS, with 50% probability of effects observed at 422 mg/L TDS. Associations between water quality measures and biological condition were variable, with approximately 48% of the variance explained by TDS. Genus-level analysis using a field sensitivity distribution approach indicated 95% of reference genera were observed at sites with TDS ≤ 281 mg/L, and 80% of genera were observed at sites with TDS ≤ 411 mg/L. This is evidence that TDS, specific conductance, or SO42- can be used to establish dissolved solids levels for streams influenced by Appalachian coal mining above which aquatic life effects are increasingly probable. / Master of Science

As embedded systems continue to evolve and the number of applications they support continues to increase, so does the diversity of the hardware they employ. As a result, the Field Programmable Gate Arrays (FPGAs), which have become fundamental elements in their design, have advanced in size and complexity as well. Because of this, it is now impossible to ignore the security implications that accompany such a progression. It is then not only important to prevent malicious attacks targeted at FPGAs from extracting the intellectual property contained in their configuration, but to now extend the research in this field by providing a cross-platform solution capable of securing the integrity of FPGA configurations at run-time. Today, there exist myriad attack strategies employed against FPGAs, the majority of which are seen in the form of semi-invasive attacks. These attacks manipulate the configuration of an FPGA and typically modify the state of the transistors that make up said configuration. This thesis introduces a multi-platform method for checking the integrity of an FPGA's configuration. The details of the system's design and implementation are discussed in addition to the analysis of the design trade-offs met when employing the system across multiple FPGA families. The system is implemented entirely in hardware and resides on-chip, providing an FPGA the ability to act as private entity capable of successfully detecting when it has been maliciously attacked. / Master of Science

Yes / Much of the development of model-based design and dependability analysis in the design of dependable systems, including software intensive systems, can be attributed to the application of advances in formal logic and its application to fault forecasting and verification of systems. In parallel, work on bio-inspired technologies has shown potential for the evolutionary design of engineering systems via automated exploration of potentially large design spaces. We have not yet seen the emergence of a design paradigm that effectively combines these two techniques, schematically founded on the two pillars of formal logic and biology, from the early stages of, and throughout, the design lifecycle. Such a design paradigm would apply these techniques synergistically and systematically to enable optimal refinement of new designs which can be driven effectively by dependability requirements. The paper sketches such a model-centric paradigm for the design of dependable systems, presented in the scope of the HiP-HOPS tool and technique, that brings these technologies together to realise their combined potential benefits. The paper begins by identifying current challenges in model-based safety assessment and then overviews the use of meta-heuristics at various stages of the design lifecycle covering topics that span from allocation of dependability requirements, through dependability analysis, to multi-objective optimisation of system architectures and maintenance schedules.