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Title: IDEOLOGICALLY MOTIVATED INTENTIONAL ADULTERATION: THEORY INTO INDUSTRIAL APPLICATION
Creator: DeVuyst, Adrian Jeffrey
Date: 2021
Description: Ideologically motivated intentional adulteration is an attempt to cause harm to consumers of food. Within the context of the United States of...
Show moreIdeologically motivated intentional adulteration is an attempt to cause harm to consumers of food. Within the context of the United States of America (US), the current methods of addressing this risk are evolving in the modern post-Food Safety Modernization Act (FSMA) era. Currently, the US has the Food and Drug Administration (FDA), which requires companies to have a food defense plan with a risk assessment, mitigation strategies, and recordkeeping. Additional options from Global Food Safety Initiatives (GFSI) benchmarked standards offer additional options for a company. However, even with these standards companies are still being impacted by intentional adulteration. Historical examples from the poisoning of bread in Hong Kong during British occupation and spreading of bacteria on salad bars by the followers of Rajneesh, to more modern examples of putting needles in strawberries and urinating on production equipment show a food defense system that is not always able to address intentional adulteration. The question of why companies are still having intentional adulteration comes up. The lack of food defense events and primary research on the topic creates a system where individual companies must gather data. Evaluations and surveys at a manufacturing site, N=11, indicates that there is high confidence among front line workers about their level of knowledge, but workers are unable to articulate the basic principles of food defense. Each individual company is required to create a personalized food defense system in the status quo, but the results of the survey given suggests that the data they could gather may be insufficient to create an effective food defense system.
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Title: Computationally Efficient Predictive Control Strategies for Autonomous Vehicles
Creator: Bhattacharyya, Viranjan
Date: 2021
Description: This thesis aims at developing computationally efficient (hence real-time applicable) control strategies for autonomous vehicles in the...
Show moreThis thesis aims at developing computationally efficient (hence real-time applicable) control strategies for autonomous vehicles in the presence of uncertainty, while incorporating high fidelity vehicle dynamics. The motivation for the control strategies is to ensure safety and improve energy efficiency of the vehicles. In this research, an effort has been made to develop control strategies to strike a balance between these competing factors. The specific contributions are: development of a new hierarchical control framework that can guarantee avoidance of red-light idling in the presence of uncertainty in preceding vehicle information/prediction in connected environment (hence improves system mobility); exploitation of a data-driven modeling approach for identifying a linear predictor for the nonlinear vehicle dynamics, which facilitates formulation of a convex equivalent problem of the original non-convex problem (hence facilitates computational tractability); introduction of a novel vehicle dynamics-aware fast game-theoretic planner for behavior and motion planning of vehicles in uncertain and unconnected environments. This thesis explores both the possible directions of future autonomous vehicles: connected and unconnected autonomous vehicles. In particular, the first problem relates to longitudinal fuel efficient driving (eco-driving) in a connected urban environment, where the connected and automated vehicles (CAVs) aim at the improvement of fuel efficiency and reduction of red-light idling (stop and go motion). The CAVs also focus on ensuring collision avoidance with the preceding vehicles despite the prediction uncertainty in future trajectory of preceding vehicles. This problem assumes vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication, and is a longitudinal control problem. The next problem considers the uncertainty in prediction of future states of neighbouring vehicles in an unconnected environment and involves both lateral and longitudinal control. Following previous research, the interactive nature of driving is modeled using game-theory and a computationally efficient game-theoretic planner is introduced. Simulation results show the efficacy of the proposed methods in terms of computational tractability and fuel-efficiency.
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Title: Modeling and Control Methods for Boundary Constrained Soft Robots
Creator: Zhou, Qiyuan
Date: 2021
Description: Soft and deformable robots have been an active field of research in the past few years. However, they are limited in that they cannot apply...
Show moreSoft and deformable robots have been an active field of research in the past few years. However, they are limited in that they cannot apply much force to an environment due to the limitations of the flexible materials from which they are made of. To help overcome this limitation, a new architecture named the Jamming and Morphing Enabled Bot Array (JAMoEBA) system was conceived. This system consists of a flexible outer membrane which encloses an interior composed of a granular medium. Active sub-units along the flexible outer membrane allow for actuation and locomotion of the system. The granular material coupled with the flexible outer membrane allows the robot to maintain the characteristics typically associated with soft robots (continuum, compliant, configurable). At the same time, the granular material is also able to undergo a solid phase transition with the application of pressure to the flexible outer membrane and allow the system to behave more like a rigid robot if needed. This allows for the robot system to exploit the desirable characteristics of both soft and rigid robots in its tasks.The purpose of this thesis is to offer a discussion and demonstration of various simulation methods for the physically accurate modeling of the JAMoEBA constrained boundary robotic system and to show some of the control methods which have been investigated within the selected modeling framework. Simulation methods based on Lennard-Jones (L-J) potentials, non-smooth contact dynamics (NSCD), as well as the discrete element methods based on complementarity (DEM-C) and penalty (DEM-P) conditions as implemented in the open source physics library Project Chrono are considered. Comparisons are made in the areas of physical accuracy, computational efficiency, and feature availability in the consideration of the best simulation method for the JAMoEBA system. Investigations of control strategies such as leader-follower and heuristics based approaches are carried out using the selected simulation method. Finally, a framework for self contained localization which relies on measurements from onboard sensors and linear Kalman filtering is tested within the simulation framework, and the effectiveness of approximating the shape of the JAMoEBA system using elliptical Fourier descriptors is shown.The main contributions made in this thesis are in the areas of suitable modeling methods, controls strategies, and localization techniques for the novel boundary constrained JAMoEBA soft robot architecture. The work done serves as a solid foundation for the future study of this novel soft robotic architecture due to the demonstration of successful methods for modeling, control, and localization of the system. The work presented is not meant to be a comprehensive or deep dive into any one specific area, but rather a jumping off point for future areas of research.
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Title: EFFECTIVENESS OF CLEANING STRATEGIES FOR REMOVING MILK CHOCOLATE FROM PILOT-SCALE PIPE/VALVE ASSEMBLY AND CHOCOLATE PROCESSING EQUIPMENT
Creator: Zhang, Liyun
Date: 2019
Description: Dark chocolate manufactured on shared processing lines with milk chocolate is a high-risk food for consumers with milk allergy. Inadequate...
Show moreDark chocolate manufactured on shared processing lines with milk chocolate is a high-risk food for consumers with milk allergy. Inadequate cleaning of shared chocolate manufacturing equipment can result in milk contamination of subsequent products, and product recalls. Limited information is available on the effectiveness of different cleaning procedures for preventing the transfer of milk to dark chocolate processed on shared equipment. Pilot-scale experiments investigated the effectiveness of three dry cleaning methods: 1) no cleaning, 2) pig purging, and 3) a cocoa butter flush (40°C, 1 hour) for removing milk chocolate residue from a heated (40ºC) standard (1.5” OD) sanitary stainless steel pipe (30.5 cm length) and attached butterfly or ball valve. After cleaning, milk-free dark chocolate (~27 kg, 40°C) was pumped through the pipe/valve combination. Dark chocolate push-through samples were collected and analyzed for milk concentrations with a Neogen Veratox total milk ELISA kit. Experiments with no cleaning resulted in initial milk concentrations up to 6,070 (9.6% CV) ppm milk and up to 14,900 (0.3% CV) ppm milk for the pipe/butterfly valve and the pipe/ball valve, respectively. Cocoa butter recirculation through the pipe/butterfly valve decreased initial milk concentrations to 680 (10.3% CV) – 2720 (2.6% CV) ppm milk. Use of a pig purging dramatically reduced milk levels to 45 (4.3% CV) – 180 (15.7% CV) for the pipe/butterfly valve and below limit of quantification of ELISA (LOQ, 2.5 ppm milk) for the pipe/ball valve. After most cleaning treatments, > 14 kg of dark chocolate push-through was required to obtain milk levels < LOQ.A second set of pilot-scale experiments determined the efficacy of cleaning procedures for removing milk chocolate from selected chocolate processing equipment. Three cleaning methods explored removal of milk chocolate from a ball mill and conche: 1) no cleaning, 2) a cocoa butter flush (40°C, 5 min), and 3) wet cleaning (detergent-rinse-air dry). After cleaning, three batches of milk-free dark chocolate (40°C) were processed in the ball mill (~0.35 kg) and conche (2.5 kg), and each batch was collected and analyzed for milk. Milk chocolate (1.5 kg) was processed on a 3-roll refiner, followed by push-through with dark chocolate (~8 kg), with 0.3 kg samples collected at 5-min intervals. Milk was not detected (Show less

Title: Towards Assisting Human-Human Conversations
Creator: Nanaware, Tejas Suryakant
Date: 2021
Description: The idea of the research is to understand the open-topic conversations and ways to provide assistance to humans who face difficulties in...
Show moreThe idea of the research is to understand the open-topic conversations and ways to provide assistance to humans who face difficulties in initiating conversations and overcome social anxiety so as to be able to talk and have successful conversations. By providing humans with assistive conversational support, we can augment the conversation that can be carried out. The AdvisorBot can also help to reduce the time taken to type and convey the message if the AdvisorBot is context aware and capable of providing good responses.There has been a significant research for creating conversational chatbots in open-domain conversations that have claimed to have passed the Turing Test and can converse with humans while not seeming like a bot. However, if these chatbots can converse like humans, can they provide actual assistance in human conversations? This research study observes and improves the advanced open-domain conversational chatbots that are put in practice for providing conversational assistance.While performing this thesis research, the chatbots were deployed to provide conversational assistance and a human study was performed to identify and improve the ways to tackle social anxiety by connecting strangers to perform conversations that would be aided by AdvisorBot. Through the questionnaires that the research subjects filled during their participation, and by performing linguistic analysis, the quality of the AdvisorBot can be improved so that humans can achieve better conversational skills and are able to clearly convey their message while conversing. The results were further enhanced by using transfer learning techniques and quickly improve the quality of the AdvisorBot.
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Title: EXAMINING THE ROLES OF PUBLIC STIGMA AND ACCULTURATION ON CARE-SEEKING IN PAKISTANIS
Creator: Laique, Aamir
Date: 2021
Description: Pakistani Americans face bi-directional cultural influences related to their heritage culture and the mainstream culture of the host. The...
Show morePakistani Americans face bi-directional cultural influences related to their heritage culture and the mainstream culture of the host. The present study examined the impact of culture on the relationship between public stigma and care-seeking attitudes. A sample of 158 Pakistani Americans was collected using MTurk. Hierarchical regression was conducted to examine the moderating effect of heritage acculturation and mainstream acculturation on the relationship between public stigma and care-seeking. Multiple regression analysis predicting care-seeking from public stigma, heritage acculturation, and mainstream acculturation did not yield a statistically significant model. Hierarchical regression analyses examining the moderating effect of heritage acculturation and mainstream acculturation were non-significant. Acculturation had no notable impact on stigma and care-seeking. This study was unable to demonstrate significant results. Future considerations should include inter-generational differences, other forms of stigma that may play a crucial role, and inclusion of different measures to determine if there are other scales better suited for the target population.
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Title: Unsupervised Learning of Visual Odometry Using Direct Motion Modeling
Creator: Andrei, Silviu Stefan
Date: 2020
Description: Data for supervised learning of ego-motion and depth from video is scarce and expensive to produce. Subsequently, recent work has focused on...
Show moreData for supervised learning of ego-motion and depth from video is scarce and expensive to produce. Subsequently, recent work has focused on unsupervised learning methods and achieved remarkable results which surpass in some instances the accuracy of supervised methods. Many unsupervised approaches rely on predicted monocular depth and so ignore motion information. Moreover, unsupervised methods which do incorporate motion information do so only indirectly by designing the depth prediction network as an RNN. Hence, none of the existing methods model motion directly. In this work, we show that it is possible to achieve superior pose estimation results by modeling motion explicitly. Our method uses a novel learning-based formulation for depth propagation and refinement which transforms predicted depth maps from the current frame onto the next frame where it serves as a prior for predicting the next frame's depth map. Experimental results demonstrate that the proposed approach surpasses state of the art techniques for the pose prediction task while being better or on par with other methods for the depth prediction task.
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Title: Integrity based landmark generation: A method to generate landmark configurations that guarantee mobile robot localization safety
Creator: Chen, Yihe
Date: 2020
Description: From the bronze-age city Nineveh to the modern metropolitan like Tokyo, traffic shape cities and profoundly affect the life of people. Similar...
Show moreFrom the bronze-age city Nineveh to the modern metropolitan like Tokyo, traffic shape cities and profoundly affect the life of people. Similar to how the wide-spreading of automobile had modified the modern cities in early 20th century, we are now standing on the eve of yet another traffic revolution. With the vast spreading of autonomous/semi- autonomous robotics application, it is important for the urban designers to design or retrofit urban environment that is safe and friendly to the autonomous robots; As more robots are deployed in life-critical situations, such as autonomous passenger vehicles, it is imperative to consider their safety, and in particular, their localization safety. While it would be ideal to guarantee safety in any environment without having to physically modify said environment, this is not always possible and one may have add landmarks or active beacons to reach an acceptable level of safety for landmark-based localization. Localization safety is assessed using integrity, the primary safety metric used in open-sky aviation applications that has been recently applied to mobile robots and can ac- count for the impact of rarely occurring, undetected faults. Conventional integrity monitor- ing method has high dependency on GPS system, while the traditional Global Navigation Satellite System - Inertia Measurement Unit (GNSS-IMU) based localization does not ap- plied in the metropolitan areas due to the signal blocking and multi-pathing problem caused by high-rise structures. Thus, this dissertation concentrates on the feature based integrity monitoring method. This dissertation formulates environmental localization safety problem as a system- atic optimization problem: given the robot’s trajectory and the current landmark map, add the minimal number of new landmarks at certain location such that the integrity risk along the trajectory is below a given safety threshold. This dissertation proposes two algorithms to solve the problem: Integrity-based Landmark Generator (I-LaG) and Fast I-LaG. I-LaG adds fewer landmarks but it is relatively computationally expensive; Fast I-LaG is less com- putationally intensive at the expense of more landmarks. Both simulation and experimental results are presented.
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Title: ENHANCED OPTICAL TOMOGRAPHY IN DIFFUSE MEDIA USING OPTICAL GATING OF EARLY PHOTONS
Creator: Ghosh, Aishwarya
Date: 2020
Description: Tissue biopsies, where a volume of tissue is removed from a patient, typically through needle extraction, provides critical information about...
Show moreTissue biopsies, where a volume of tissue is removed from a patient, typically through needle extraction, provides critical information about the cellular and molecular aspects of an individual patient’s health and/or disease. However, current pathological assessments of tissue biopsies evaluate less than 1% of the volume of the tissue (e.g., one to a few 5-micron slices are sectioned out of the biopsy and stained/processed for microscopic analysis). Since the bulk of tissue biopsy is carried out through optical imaging (absorption or fluorescence), a more 3D, “whole-biopsy” view is conceivably possible with optical projection tomography (OPT). The challenge with OPT has been that for clinically relevant sized biopsies, most photons undergo multiple scattering events that lead to loss of spatial resolution that makes accurate pathological analysis intractable. In my MS thesis, I worked on the development of an enhanced OPT system that employs optical gating based on non-linear up-conversion of infrared ultrashort laser pulses to isolate “early-arriving” photons that experience significantly less scatter than the bulk of photons transiting a scattering biological sample. Considering the complexity of such a system, the entirety of my MS thesis work was spent constructing and testing the femtosecond optical gated OPT system and though I was unable to validate its operation in biological samples, simulations suggest that the properties we were able to achieve could allow high resolution optical imaging in 0.1-1 cm-diameter specimens.
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Title: Framework For Cloud-Based BIM Governance
Creator: Mehraj, Isma
Date: 2020
Description: Due to the rapid adoption of building information modeling (BIM) in the architecture, engineering, and construction (AEC) every building can...
Show moreDue to the rapid adoption of building information modeling (BIM) in the architecture, engineering, and construction (AEC) every building can be visualized and interpreted even before its foundation touches the ground. BIM methods are expanding and have entered mainstream use that requires immediate consideration. BIM is new and difficult to operate as mostly due to the enormous amount of data that causes improper data management. The objective of this study is to formulate a cloud-based BIM governance framework with a focus on practical issues for its implementation in the construction organizations. A framework was developed to study Data Management, Team Collaboration, Data Organization, and Legal Assurance as major constructs. It is expected that the constructs will provide a benchmark for BIM cloud governance implementation for BIM /VDC engineers to follow. The incorporation of this framework in BIM practices would produce new opportunities for the AEC community to work in collaboration and increase efficiency in data sharing. A survey among a wide spectrum of BIM/VDC practitioners from major construction organizations in the United States was conducted to explore and find evidence of the strength of the constructs. We anticipate that this framework will provide a basis for assessment and recognition of pivoting, driving factors for practical and effective BIM implementation.
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Title: Exploring differences in eating disorder symptomatology and treatment outcomes between sexual minority and heterosexual women in eating disorder treatment programs
Creator: Murray, Matthew Ford
Date: 2020
Description: Research on eating disorder (ED) symptomatology in sexual minority (SM) women is limited and has demonstrated inconsistent findings with...
Show moreResearch on eating disorder (ED) symptomatology in sexual minority (SM) women is limited and has demonstrated inconsistent findings with respect to how they differ from heterosexual women. Further, many studies combine SM women into one group, potentially masking important sub-group differences. Existing data appears to suggest that SM women may be at similar or increased risk for certain types of disordered eating behaviors and present with body image concerns that may differ from heteronormative female body ideals. However, it is unclear how weight and shape control behaviors differ across sexual orientations in women seeking treatment for EDs, and if there are differences in treatment outcomes. The present study used analyses of variance and covariance to test 1) group differences in frequency and severity of ED symptomatology and 2) differences in group by time interaction effects as an indicator of treatment outcomes in a sample of 3,120 adult women of diverse sexual orientations who presented for ED treatment between 2015 and 2018. Participants identified their sexuality as heterosexual, lesbian, bisexual, or other/unsure. Results indicated notable group differences in ED symptoms upon admission to treatment. Bisexual women, in particular, presented to treatment at younger ages, with higher BMIs, and more severe illnesses than heterosexual women. Further, results from the present study suggest that despite such differences, women across sexual orientation groups achieved similar treatment outcomes. These findings underscore the importance of subgroup analyses of ED symptoms in SM women and have both clinical and research implications related to ED psychopathology in this population.
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Title: Testing Models of Minority Stress and Cognitive Escape in a Large Sample of Lesbian/Gay Individuals
Creator: Manser, Kelly
Date: 2020
Description: Compared to heterosexual individuals, gay/lesbian individuals experience health and sociopolitical disparities. Health disparities include...
Show moreCompared to heterosexual individuals, gay/lesbian individuals experience health and sociopolitical disparities. Health disparities include higher prevalence of binge drinking, tobacco use, and cardiovascular disease (CVD) among gay/lesbian individuals. Sociopolitical disparities are rooted in structural stigma and include policies and norms that fail to protect, or actively discriminate against, gay/lesbian individuals. These health and sociopolitical disparities can be understood by converging two theories previously tested among gay/lesbian individuals – minority stress and cognitive escape. Minority stress theory asserts factors such as structural stigma may relate to proximal stress and negative health sequelae in targeted minority groups, while cognitive escape theory suggests escape-related behaviors like substance use may mediate links between systemic factors and individual health. This study used binary logistic regressions to test mediation models in which substance use mediated links between structural stigma and health within a large sample of gay/lesbian individuals. Structural stigma was operationalized as number of sexual orientation anti-discrimination laws, health was operationalized as presence versus absence of any CVD conditions, and substance use was operationalized as binge drinking and tobacco use. Models were tested in an aggregated sample, and also in sex/gender subsamples. In bivariate and component-path analyses, structural stigma predicted smoking frequency across samples. Stigma-binge drinking linkages were more salient among lesbian women compared to gay men. According to Sobel tests, smoking status mediated the stigma-CVD status relation for males-only and combined-sex samples. Study strengths, limitations, and implications are discussed.
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Title: SALMONELLA SURVIVAL AND TRANSCRIPTOMIC RESPONSE ON FRESH-CUT CANTALOUPE FLESH WITH AND WITHOUT ORGANIC ACID PRETREATMENT
Creator: Zhou, Xinyi
Date: 2020
Description: Outbreaks of Salmonella enterica associated with fresh-cut melons are becoming more frequent in recent years. Antimicrobial activity of...
Show moreOutbreaks of Salmonella enterica associated with fresh-cut melons are becoming more frequent in recent years. Antimicrobial activity of organic acids on fresh-cut melons have been previously studied. However, little is known about the molecular mechanism behind the antimicrobial activity of organic acid.Four strains of S. enterica were utilized: Newport 36796 and 339652, and Typhimurium LT2 and 46249. Both high and low inoculation levels were performed. For low level, each strain was individually cultured and spot-inoculated onto separate 100 g untreated fresh-cut cantaloupe samples resulting in 4 log-CFU/g. For high level, samples were first submerged into 2% citric acid or malic acid for 1 minute or left as untreated control. Cantaloupe were spot inoculated with one of four strains which resulted in 7-log CFU/g. All inoculated samples were air-dried for 1 h then stored at 4°C for 7 d in deli containers. Enumeration was conducted at 0, 1, 3, 5, and 7 d. Duplicate samples were used in each of three independent trials and results were analyzed by Student’s t-test, p≤0.05. Samples for sequencing were prepared using the TruSeq Stranded mRNA kit and run on a MiSeq according to the manufacturer instructions.For low inoculation level, population of all four strains increased significantly from 0 to 3 d. The two cantaloupe outbreak-related strains (Newport 339652 and Typhimurium 46249) increased significantly between 0 and 7 d from 3.44±0.11 to 3.76±0.13 and 3.36±0.12 to 3.78±0.19 log CFU/g, respectively. For high inoculation level, the population on the untreated cantaloupe was 6.55±0.18 log CFU/g at 7 d, whereas it was significantly lower on the citric and malic acid-treated cantaloupes (6.26 ± 0.09 log CFU/g and 6.07 ± 0.18 log CFU/g). After 1 d, S. enterica genes were downregulated up to 437.4-fold compared and upregulated up to 23.2-fold. The notable downregulated genes encoded proteins related to catalyzing metabolism (L-aspartate oxidase) and also related to nutrient uptake (PstC).The results of this study can aid in understanding population dynamics of S. enterica on fresh-cut cantaloupes and efficacy of malic and citric acids. The results can also aid in understanding mechanism underlying S. enterica survival on fresh-cut cantaloupes.
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Title: PREPARATION OF MG3SB2-XBIX THERMOELECTRIC MATERIAL AND THEIR LASER SINTERING BEHAVIOR
Creator: Xiao, Xudong
Date: 2020
Description: In the introduction part, a novel thermoelectric material, Zintl compounds were introduced due to its potential high thermoelectric...
Show moreIn the introduction part, a novel thermoelectric material, Zintl compounds were introduced due to its potential high thermoelectric performance in low-temperature applications as thermoelectric devices. Recent researches focused on Mg3Sb2-based Zintl Compounds was summarized in this article, and the general methods and its limitations to fabricate Mg3Sb2-based thermoelectric modules were introduced. Thus, a novel selective laser melting process was introduced, and it has enormous potential to fabricate Mg3Sb2-based thermoelectric modules in commercial applications. What’s more, the challenges of selective laser melting method were also discussed in the articles. For developing selective laser melting as the mature method to fabricate Mg3Sb2-based thermoelectric modules, many works and researches need to be done. In my project, the powder of Mg3.1(Sb0.3Bi0.7)1.99Te0.01 thermoelectric material was synthesized by using the mechanical alloying process and the proper particle size and distribution of powder using for selective laser melting was obtained by increasing the time of mechanical alloying. The thermoelectric properties of the powder prepared by mechanical alloying were measured, and it shows the powder still in a good performance after a long-time mechanical alloying particle reduction process. Finally, the obtained powder was treated by different parameters of continued wave fiber laser. The morphology and composition of the sintered area were analyzed to better understanding the process of laser sintering. More work needs to be done for using a selective laser melting method to fabricate Mg3Sb2-based thermoelectric modules in the future.
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Title: FAST AUTOMATIC BAYESIAN CUBATURE USING MATCHING KERNELS AND DESIGNS
Creator: Rathinavel, Jagadeeswaran
Date: 2019, 2019-12-20
Publisher: Chicago
Description: Automatic cubatures approximate multidimensional integrals to user-specified...
Show moreAutomatic cubatures approximate multidimensional integrals to user-specified error tolerances. In many real-world integration problems, the analytical solution is either unavailable or difficult to compute. To overcome this, one can use numerical algorithms that approximately estimate the value of the integral. For high dimensional integrals, quasi-Monte Carlo (QMC) methods are very popular. QMC methods are equal-weight quadrature rules where the quadrature points are chosen deterministically, unlike Monte Carlo (MC) methods where the points are chosen randomly. The families of integration lattice nodes and digital nets are the most popular quadrature points used. These methods consider the integrand to be a deterministic function. An alternate approach, called Bayesian cubature, postulates the integrand to be an instance of a Gaussian stochastic process.
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Title: Silkworm silk - CNT composite fibers: fabrication, characterization and application in cell stimulation for tissue regeneration
Creator: Zheng, Shuyao
Date: 2019
Description: Silk fibroin, a structural protein of the Bombyx mori cocoons, is widely studied for biomedical applications because of its strong mechanical...
Show moreSilk fibroin, a structural protein of the Bombyx mori cocoons, is widely studied for biomedical applications because of its strong mechanical property, biocompatibility, low degradation rate and ease of processing. In this study, we incorporated functionalized CNT in silkworm silk proteins to generate biocomposite fibers by electrospinning. The electro-spun (E-spun) fibers were unidirectionally aligned with a diameter at the sub-micrometer scale, mimicking the locally oriented ECM proteins in native tissues. The addition of a minute amount of CNT not only reinforced the stability and the mechanical strength of the flexible scaffolds, but also rendered the fibers electrical conductivity to not only facilitate the E-spun fiber formation but also grant the fibers an additional functionality that can be utilized for cell stimulation. It is known that endogenous electric field is present in the human body at various locations and plays critical physiological roles through its effect on cell proliferation, migration and activation mediated by its interference with growth factor secretion and intracellular signaling pathways. Electrical stimulation (ES) has been widely investigated as a potential method to regulate cell functions for the treatment of a number of diseases. It has been reported that in dermal fibroblasts, ES induces the secretion of FGF-1 and FGF-2 which promotes cell proliferation, contraction, migration, and activation/differentiation into myofibroblasts for increased collagen synthesis in favor of tissue repair. In this work, the modulation effect of the aligned E-spun SWS-CNT fibers was examined by their application in inducing polarization and activation of fibroblasts with cellular deficit, like those from pelvic organ prolapse (POP) patients. These cells are characterized by low productivity of collagen with abnormally high COLI/COLIII ratio, leading to a loose and fragile collagen network, decreased integration among the tissue constituents and reduced tissue strength. Electrical stimulation boosted the collagen productivity by 20 folds in cells on silk-CNT than on pure silk due to silk-CNT’s high electrical conductivity. The developed approach can be potentially utilized to remedy the dysfunctional fibroblasts for therapeutic treatment of diseases and health conditions associated with collagen disorder.
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Title: NUMERICAL ANALYSIS ON MAXIMUM LIKELIHOOD ESTIMATORS FOR LINEAR PARABOLIC STOCHASTIC PARTIAL DIFFERENTIAL EQUATIONS
Creator: Zhang, Jun
Date: 2019
Description: The thesis contributes to the numerical analysis on statistical inference for stochastic partial differential equations (SPDEs). We study the...
Show moreThe thesis contributes to the numerical analysis on statistical inference for stochastic partial differential equations (SPDEs). We study the maximum likelihood estimation problem of the drift parameter for a large class of linear parabolic SPDEs. As in the existing literature on statistical inference for SPDEs, we take a spectral approach, and assume that one path of the first N Fourier modes is observed continuously in a fixed finite time interval [0, T]. We first provide a review of the asymptotic properties of the maximum likelihood estimator (MLE) of the drift parameter in the large number of Fourier modes regime, N  ∞, while the time horizon T > 0 is fixed. The main part of this thesis is dedicated to the numerical study of the asymptotic properties of the MLEs for two examples of linear parabolic SPDEs: the one-dimensional stochastic heat equation and a d-dimensional linear, diagonalizable, parabolic SPDE, where d  ℕ. For the one-dimensional stochastic heat equation, we perform the sensitivity analysis to assess the effect of changes in model parameters on the speed of convergence of the MLE. For the second linear parabolic SPDE, our simulations verify the theoretical results in the literature that both the consistency and asymptotic normality of the MLE hold for such equation only when d ≥ 2.
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Title: An experimental study on the effects of partial sleep deprivation on disordered-eating urges and behaviors
Creator: Johnson, Nicole Kathryn
Date: 2020
Description: Previous research has linked sleep disturbances with disordered eating. Studies have also shown that one night of partial sleep deprivation...
Show morePrevious research has linked sleep disturbances with disordered eating. Studies have also shown that one night of partial sleep deprivation causes increases in food intake and appetite disturbances. However, the effects of sleep deprivation on disordered eating are unclear as research has yet to examine the effects of one night of partial sleep deprivation (≤ 4 hours of sleep) on disordered eating in a representative adult female sample. Adult, female participants (N=40) completed eligibility and baseline measures reporting medical conditions, eating disorder symptoms, sleep disturbances, depressed mood, and anxiety symptoms. Participants were randomized to either the sleep-deprived condition (~50% of their average sleep duration) or the habitual-sleep condition (~100% of their average sleep duration). The morning after the sleep condition, participants completed self-report appetite and disordered eating measures before and after consuming a test meal and later that evening. The following statistical analyses, adjusted for multiple comparisons (p<0.002), found no significant group differences: independent samples t-tests (outcome: pre-meal appetite, disordered eating, and test-meal consumption), multivariate analyses of variance (MANOVAs; outcome: pre- and post-meal area under the curve disordered eating and appetite), repeated measures ANOVAs (time X group; outcome: pre- and post-meal appetite and disordered eating), analyses of covariance (ANCOVAs; controlling for pre-meal ratings; outcome: disordered eating at follow-up), and chi-square tests (outcome: follow-up appetite and disordered eating). Despite finding no support for the effect of sleep deprivation on disordered eating, this study extends previous research as a novel study using the experimental manipulation of sleep deprivation to examine its effects on disordered eating.
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Title: Self-Stigma & Vicarious Stigma Experienced by Parents of Children with Mental Health Challenges
Creator: Serchuk, Marisa Dyan
Date: 2019
Description: Research has been limited regarding the stigma experienced by parents of children with mental health challenges. It is commonly understood...
Show moreResearch has been limited regarding the stigma experienced by parents of children with mental health challenges. It is commonly understood that stigma effects people with lived-experience (e.g., a child with mental health challenges), however, stigma has been noted to have a wide scope, which extends to family members as well. Parents of children with mental health challenges have been found to endorse aspects of self-stigma, specifically regarding public stereotypes of blame and feelings of incompetence. Vicarious stigma is a fairly new area of research, which describes the sad and/or angry response a parent may experience when witnessing their child being stigmatized. The purpose of this study is to examine emotional and behavioral outcomes related to specific types of stigma experienced by parents of children with mental health challenges. Archival data from a larger study of adult participants (N=50), who identified as having a child (age 3-10 years old) with mental health challenges, completed measures examining self-stigma, vicarious stigma, stress, depression, quality of life, disclosure, secrecy coping, and help-seeking. A novel measurement for vicarious stigma was introduced and examined in this study. Results found higher levels of self-stigma and dimensions of vicarious stigma were associated with higher levels of depression as well as diminished quality of life. Higher levels of self-stigma were also associated with lower perceived benefits of disclosing and greater levels of secrecy coping. These findings highlight the importance of further examining the role of stigma for parents of children with mental health challenges.
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Title: SUSTAINED RELEASE OF PHOSPHATE-BASED THERAPEUTICS FOR ATTENUATION OF PATHOGEN-INDUCED PROTEOLYTIC MATRIX DEGRADATION
Creator: Bittencourt Pimentel, Marja
Date: 2019
Description: Loss of the normal intestinal microbiome community structure and its replacement by pathogenic microbes contributes to severe persistent...
Show moreLoss of the normal intestinal microbiome community structure and its replacement by pathogenic microbes contributes to severe persistent inflammation in diseases such as ulcerative colitis and inflammatory bowel disease. While host-derived proteases are known to contribute to this pathogenesis, the role of increased production of microbial-secreted proteases due to virulent phenotypes remains unclear. Following surgical removal of diseased intestinal tract, increased bacterial protease expression is a key phenotype involved in intestinal healing impairment. Antibiotic administration is ineffective for treating these complications as it inadvertently eliminates normal flora while allowing pathogenic bacteria to acquire antibiotic resistance. Prior research has shown that intestinal phosphate depletion in the surgically stressed host triggers bacterial virulence which is suppressed under phosphate abundant conditions. To address this issue our previous work has demonstrated that the use of free monophosphate (-Pi) and polyphosphate (-PPi), as well as post-loaded PPi nanoparticles (NP-PPi) attenuate collagenase production of gram-negative (Pseudomonas aeruginosa and Serratia marcescens) but not gram-positive (Enterococcus faecalis) pathogens expressing high collagenolytic activity. Due to the variation in phosphate metabolism among microbial species we investigated the in vitro efficacy of a combination treatment of phosphates delivered in a sustained release format using NP-PPi and NP-Pi on collagenase and biofilm attenuation across gram-positive and gram-negative test pathogens.Collagenase screening was assessed using two in vitro models. The first in vitro assay involved culturing pathogens in the presence and absence of NP-Pi and/or NP-PPi treatment using two-dimensional (2D) commercially available fluorogenic protease-sensitive peptide substrates. Although these substrates are among the most commonly used for screening protease activity and inhibition in vitro, their application does not translate to three-dimensional (3D) matrix degradation. Additionally, the addition of drug-loaded nanoparticles directly in bacterial culture does not recapitulate the in vivo sustained release of phosphates due to nanoparticles embedded within tissue. Thus, the second model involved the development of a novel cell culture platform which utilized a proteolytically degradable hydrogel scaffold and a non-degradable nanocomposite hydrogel scaffold. In this assay NP-Pi and NP-PPi were entrapped in a non-degradable poly(ethylene) glycol (PEG) hydrogel to form of a nanocomposite matrix which served as a reservoir for sustained release of phosphates. Bacteria producing high levels of proteases were cultured in the presence of the nanocomposite phosphate releasing reservoir and the proteolytically degradable PEG hydrogel scaffold to determine the efficacy of sustained release of phosphates in attenuating proteolytic hydrogel degradation. To correlate matrix degradation with bacterial enzymes secreted in the culture medium, we also developed a method to efficiently measure hydrogel degradation rate until complete material degradation with a greater degree of accuracy compared to the commonly employed method utilizing gravimetric measurements in gel wet weight. Combined, the in vitro platform and our proposed degradation assay provide a novel approach for screening the effect of therapeutics for attenuation of bacterial protease-induced matrix degradation.The 2D in vitro study demonstrated that the combination treatment (NP-PPi + NP-Pi) confers broad spectrum efficacy for suppression of collagenase and biofilm production across test pathogens. Conversely, the 3D in vitro model demonstrated that the combination treatment (NP-PPi + NP-Pi) attenuated protease production for gram-negative pathogens, while the gram-positive test pathogen exhibited significant decreases in protease levels only in the presence of NP-Pi. Finally, our novel Sirius red absorbance assay for quantifying hydrogel degradation was found to provide greater accuracy when compared to gravimetric measurements in gel wet weight. It also enabled real-time monitoring of 3D matrix degradation kinetics as well as the time required for complete material dissolution in the presence of bacterial proteases and active human MMP-9 enzyme solutions. These findings highlight the importance of designing relevant in vitro platforms for screening therapeutic efficacy in the presence of cells and nanomaterials.
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