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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: PURIFICATION AND ANALYSIS OF BAXΔ2 PROTEIN AGGREGATES FROM MAMMALIAN CELLS
Creator: Wang, Xiling
Date: 2020
Description: BaxΔ2 is a unique isoform of the proapoptotic protein Bax that does not target mitochondria. The proapoptotic function of BaxΔ2 is through...
Show moreBaxΔ2 is a unique isoform of the proapoptotic protein Bax that does not target mitochondria. The proapoptotic function of BaxΔ2 is through forming cytotoxic aggregates in the cytosol. The cytotoxicity of BaxΔ2 is known as associated with the BH3 killing domain and the C-terminus, which recruits caspase 8. BaxΔ2 proteins without C-terminal form large cytosolic protein aggregates unable to induce caspase 8-dependent cell death. Since abnormal cytosolic protein aggregates often contain complexes of proteins that involved in many diseases, we would like to purify BaxΔ2 aggregates and examine their components. In this study, we expressed GFP-tagged BaxΔ2(Δ6) in the Bax-negative HCT116 cell line and purified the aggregates via different digestion processes. We found that most aggregates were trapped into a DNA pellet after cell lysis. Digestion with DNase could release the aggregates, which were susceptible to detergent solvent. The yield of purification is very low and needed improvement. The results from Western Blot showed that, in addition to BaxΔ2 proteins, stress granule protein TIAR was also potentially in the aggregates. Identification of the components inside aggregates will help us to understand the mechanism of BaxΔ2 cytotoxicity.
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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: Regenerating the Jordan River: Through Ecological and Sociocultural Interventions
Creator: Shadid, Rula
Date: 2019
Description: The Jordan River is often described as one of the world’s most unique eco-systems and is attributed to serving as a cradle of history, culture...
Show moreThe Jordan River is often described as one of the world’s most unique eco-systems and is attributed to serving as a cradle of history, culture, and spirituality in the ancient and modern times. Archaeological evidence on its banks reveal signs of some of the world’s earliest existences of civilization. Its history as a meeting place for the crossing and exchange between plants, animals, and human societies, along with its strong association to three of the world’s great religions – Christianity, Islam, and Judaism – has made it a world known and important site. Being located in the Middle East, in the heart of a complex political conflict that has been ongoing since the middle of the last century, years of war, political clashes, and water and resource exploitation has reduced the river from a once lush and bio-diverse ecosystem to nothing but a polluted stream. Today the river is a “hydro-border” that divides the competing nations around it and segregates the people of the Jordan Valley in which the river runs via militarized security efforts. The conflict has left the region politically and socially segregated and has eliminated the productive exchange which once allowed the valley to thrive while efforts to protect, preserve, or rehabilitate the river are given little chance to succeed. The thesis addresses river degradation and social segregation as two interdependent issues in the Jordan Valley. It highlights saving the Jordan River as a driver for integration between the conflicting society and points to the Jordan Valley river border as a site for regenerative interventions that suggest an alternative and productive way of life in an area filled with conflict, economic distress, and spatial divide through the collaboration and exchange of efforts, ideas, and resources.
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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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Title: A NOVEL HYDROPONICS SYSTEM FOR PRODUCING SAFE AND HEALTHY SPROUTS
Creator: Azizinia, Mehdi
Date: 2019
Description: Sprouts can be considered as one of the most nutritious and cheap nutritional sources. Due to these advantages, sprouts consumption has...
Show moreSprouts can be considered as one of the most nutritious and cheap nutritional sources. Due to these advantages, sprouts consumption has increased significantly in recent decades. However, because of their susceptible nature to microbial growth, numerous outbreaks associated with this fresh produce have occurred and thus the safety of the sprout is of major concern. A novel kinetic hydroponics system (KHS) was developed to optimize an improve safe sprout production. In KHS, sprouting seeds are able to grow under water while air is continuously introduced. In this study, effect of various airflow rates and light on yield, germination percentage, and physical properties of sprout were examined. In addition, microbial growth during the shelf life of sprout grown, using conventional and KHS methods were monitored. Moreover, the efficacy of chlorine-based sanitizers for reducing microbial loads during KHS sprout production was tested. Results showed that air flow rate had a positive impact on yield. However, higher airflow (8 and 10 feet3/minute) significantly lowered yield. Also, KHS has a significant higher yield compare with conventional method (110.30±4.88 versus 66.19±2.66 g). KHS did not have positive impact on germination percentage. Germination percentage was almost the same in KHS and conventional method (80.67±1.15% versus 81.33±1.53%). Moreover, when various light wavelengths were used, germination percentage increased significantly in KHS (from 91±2.65 to 96±1% in various wavelengths). In terms of color, there were no significant differences in color of sprouts in both systems. In KHS, when dark conditions applied, stem length was significantly higher (31.32±3.55 mm) than those sprouts treated with light. For example, stem length in white light was 8.54±1.32 mm. In contrast, leaves length was significantly higher when light used (highest was 6.67±0.49 mm for combination of blue and red lights compare to 3.19±0.22 mm for dark KHS). Analyzing microbial background showed that sprouts produced in KHS had lower total aerobic counts compared with conventional system (7.24±0.49 versus 8.22±0.18 log CFU/g respectively). However, after 21 days of shelf study at 4°C sprouts in both systems almost had the same counts (10.02±0.70 versus 9.55±0.49 log CFU/g in KHS and conventional systems respectively).
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Title: DOPING OF SODIUM CHROMIUM OXIDE CATHODE MATERIALS TO ENHANCE ELECTROCHEMICAL PERFORMANCE FOR SODIUM-ION BATTERIES
Creator: wang, ziyong
Date: 2019
Description: In this project, we investigated the effects of doping several types of metals to NaCrO2 on its electrochemical performance. The doping method...
Show moreIn this project, we investigated the effects of doping several types of metals to NaCrO2 on its electrochemical performance. The doping method is aiming to stabilize the O3-type structure by partial substituting some of Cr with other metals during intercalation/deintercalation by suppressing Cr6+ migration to alkaline slab, and thus facilitate long-term cycle performance and reversible capacity. All doped NaCrO2 powders were hereby denoted to NaMe0.1Cr0.9O2 (Me=Al, Co, Ni, Mn). To achieve metal-doped NaCrO2 powders, sodium, chromium and dopant sources were mixed with various metal oxides and then subjected to 6-hour high energy ball milling, followed by heating in flow-Ar tube at 900℃ for 1 hour. Pristine NaCrO2 powder synthesized in the same process was to make comparisons with doped ones. To understand the mechanism of doping, field emission scanning microscopy (FESM) and energy Disperse Spectroscopy (EDS), as well as X-ray diffractometer (XRD), were employed to analyze the morphology and composition of final products. Benefiting from Ni doping, NaNi0.1Cr0.9O2 cell exhibited a high reversible capacity of 132 mAh g-1 at the initial cycle in a potential region between 2.0 and 3.6 V vs. Na/Na+, and 78 % of capacity retention over 70 cycles. For NaMn0.1Cr0.9O2, reversible capacity at first discharge is about 30 mAh g-1, lower than that of Ni-doped and pristine NaCrO2, while the cycle retention stays at nearly 100% after 100 cycles. The opposite charge/discharge behaviors from Ni- and Mn-doped NaCrO2 provide us a potential method for the optimization of cathode materials with the best electrochemical performance in the future.
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Title: Rapidly Deployable PV-Based Smart Irrigation System
Creator: Usta, Salih
Date: 2019
Description: There are many agricultural fields in developing countries such as Turkey which do not have electricity on site. In order to water these...
Show moreThere are many agricultural fields in developing countries such as Turkey which do not have electricity on site. In order to water these fields, there is usually a need to store water in a water reservoir nearby. This purpose is achieved by manpower or by using diesel-operated water pumps which are often inefficient and require a high degree of maintenance over time. Furthermore, extending the power supply grid to the field is not considered an option by governors, due to the high cost for a relatively small-scale application. Along with this, watering the field is done by farmers, which frequently leads to waste of water, or leads to watering one particular area of the field less than the others, which causes a drop in crop efficiency. Preventing water waste is considered an important issue in the 21st century. Also, increasing crop efficiency in a developing country is an important consideration. To prevent water waste and to enhance crop efficiency, an automated irrigation system is needed. The objective of this study is to develop a photovoltaic-based irrigation system for an agricultural field that is not tied to an existing conventional electric grid. Firstly, a stand-alone PV system is designed according to the field requirements. Secondly, a soil moisture sensor-based smart irrigation system is developed for an automated irrigation process compatible with drip irrigation systems. This system also enables users to monitor and analyze soil moisture data. By developing this type of complete irrigation mechanism, a long-term lower cost, efficient, and environmental-friendly system is designed.
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Title: Mental Health Stigma and Care-Seeking in First Generation Indian Immigrants
Creator: Shah, Binoy
Date: 2019
Description: Objective: Immigrants from India face unique obstacles, including migration related factors and cultural pressures, that may contribute to...
Show moreObjective: Immigrants from India face unique obstacles, including migration related factors and cultural pressures, that may contribute to underutilization of mental health treatment services. The present thesis examined paths between mental health stigma and care-seeking in a sample of first-generation Indian immigrants, with a specific emphasis on the influences of acculturation and parental autonomy support. Method: A sample of 201 first-generation immigrants from India was ascertained using MTurk. Path analysis was conducted to examine the relationships between public stigma of mental illness, disclosure, mental health care-seeking, parental autonomy support, and bi-directional acculturation. Results: Final model was supported by good fit indicators. Greater public stigma was associated with reduced care-seeking, but greater disclosure was associated with increased care-seeking. Interestingly, parental autonomy support, mainstream acculturation, and heritage acculturation facilitated disclosure but had no discernible impact on public stigma. Conclusions: In contrast to traditional anti-stigma strategies that focus on reducing public stigma, present results suggest that it may be more beneficial to facilitate care-seeking by targeting disclosure of status. In turn, disclosure may be promoted by facilitating autonomy supportive social networks and bi-directional acculturation.
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Title: EVALUATION OF LISTERIA MONOCYTOGENES ENRICHMENT AND COMPOSITING PROTOCOLS FROM ENVIRONMENTAL SAMPLES
Creator: Eckert, Christine
Date: 2019
Description: Environmental sampling in a food production plant is routinely conducted using devices, such as sponges or swabs, to verify cleaning...
Show moreEnvironmental sampling in a food production plant is routinely conducted using devices, such as sponges or swabs, to verify cleaning procedures and determine if any foodborne pathogens, such as Listeria monocytogenes (L. monocytogenes), are present. The devices used for environmental monitoring are enriched to improve pathogen detection. This study aims to 1) compare the limit of detection (LOD) of L. monocytogenes of two U.S. Food and Drug Administration (FDA) enrichment procedures (i.e., Bacteriological Analytical Manual (BAM) and Compliance Document) with and without food matrix, and to 2) assess the number of samples which can be wet and dry composited without loss of sensitivity from stainless steel. To compare the LOD of L. monocytogenes using UVM and BLEB, three inoculation levels (0.27±0.07, 0.59±0.05, and 1.00±0.15 CFU per 225 mL enrichment) with 30 enrichments each were used. Results showed that there was no significant difference between the number of samples where L. monocytogenes was detected for UVM and BLEB at any of the three inoculation levels. However, the limit of detection (LOD95%) for UVM/Fraser was higher than that of BLEB (2.13 and 1.44 CFU/mL, respectively). For wet compositing, 1.24±0.34 CFU of L. monocytogenes was inoculated into 45 enrichments of UVM or BLEB without food matrix and 7.2±0.18 CFU of L. monocytogenes was inoculated into 30 enrichments of UVM or BLEB with 4.13±0.12 log CFU of native microflora from Romaine lettuce wash (RLW). Secondary composite enrichments in Fraser broth were conducted at each of four different ratios: 1:1 (1 positive:1 negative), 1:2 (1 positive: 2 negative), 1:4 (1 positive: 4 negative), and 1:7 (1 positive:7 negative). There was no significant difference between the number of samples where L. monocytogenes was detected between BLEB and UVM with or without food matrix at any of the composite ratios. When comparing wet and dry compositing enrichments from stainless steel, 10.16 × 10.16 cm areas on stainless steel plates were inoculated with 464±22 CFU (2.67±0.24 log CFU) L. monocytogenes, dried for 24 h, and sponges were used to swab the surface of the plates. The sponges were then composited (into primary enrichments for dry compositing) or the secondary enrichments were composited (for wet compositing). Compositing was conducted with RLW containing 4.13±0.02 log CFU of background microflora. There was no significant difference between the number of samples where L. monocytogenes was detected for BLEB and UVM when comparing dry or wet compositing at any of the composite ratios tested. Results of this thesis will aid in determining if compositing of environmental samples is an option when L. monocytogenes is the target pathogen.
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