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- Title
- Correlating Veterans' Employment Status by Analysis of Recovery from the Recovery Assessment Scale-Short Form
- Creator
- Avezuela-Perez, Margaret
- Date
- 2020
- Description
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Past research has examined the low employment rates in veterans with serious mental illness (SMI) (Zivin et al., 2011) and the research...
Show morePast research has examined the low employment rates in veterans with serious mental illness (SMI) (Zivin et al., 2011) and the research suggests that the benefits of employment for veterans are improved mental health symptoms, better finances, and better self-esteem (Bond et al., 2001). The specific relationship between employment and recovery from SMI in individuals has been examined (Drake et al., 2001; Bond et al., 2001; Modini et al., 2016). Previous research has not examined the correlation between recovery from SMI and employment, specifically in a population of veterans with SMI. The current study examines the relationship between recovery and employment of veterans with SMI, using the Recovery Assessment Scale (RAS) as a measure of recovery. A logistic regression analysis yielded that no relationship was found between recovery and employment status. Results of this study suggest there may be other factors affecting the relationship between these two factors. Moreover, there is the possibility that there is no relationship between recovery and employment.
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- Title
- HUMAN TRAFFICKING AND THE INTERNET: EDUCATING OUR COMMUNITY OF THE GROWING PANDEMIC
- Creator
- Ali, Md
- Date
- 2020
- Description
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Human trafficking is a growing pandemic with many traffickers utilizing both the surface web and dark web to recruit and sell victims of human...
Show moreHuman trafficking is a growing pandemic with many traffickers utilizing both the surface web and dark web to recruit and sell victims of human trafficking. We will explore different cases regarding human trafficking as well as how traffickers are uti- lizing technology to conduct their criminal activities. We will be going over different research studies that went over new social engineering methods that technology has introduced into the world of human trafficking and coming to a statistical analysis on preventive measures to be aware of. With increasing advancements in encryption methods and communication the ease of this crime has been committed from one’s own bedroom. This thesis will be answering the question on how to minimize or remedy this atrocious criminal activity from society by analyzing all the recommendations from each study and finding possible solutions to avoid being a victim of human trafficking.
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- Title
- Applying Statistical Methods to Air Quality and Asthma Data in Chicago Homes
- Creator
- Abromitis, Kari
- Date
- 2020
- Description
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This thesis investigates one years’ worth of indoor and outdoor air pollution data collected from Chicago area homes in relation to results...
Show moreThis thesis investigates one years’ worth of indoor and outdoor air pollution data collected from Chicago area homes in relation to results from monthly asthma surveys taken by the residents of those homes. This examination involves the processing and calibration of this large dataset, basic statistical analysis, and analysis of asthma as related to variation of air pollution and air pollution resulting from nearby transportation sources. The data was collected as a part of the Breathe Easy project, which was funded by the HUD and involved IIT and Elevate Energy, a Chicago-based economic development organization that promotes building equality through climate action. The majority of the data processing and analysis were performed using Python and it is intended for continued use during the ongoing Breathe Easy project. The basic statistical analysis of this data led to initial investigations of how the variability of pollutants on a daily basis triggered asthma severity and symptoms. There were limited relationships observed between asthma symptoms and pollutant variability, and it was found to not be as important as overall pollutant levels. A second investigation was pursued to examine how the proximity to transportation, including Metra trains, freight trains, elevated rail trains, highways, bus lines, and busy roads, affected indoor and outdoor pollution levels at each home, as well as concurrent asthma outcomes. Similar to previous research, there was some relation for transportation closeness, particularly for highways and Metra trains, and pollution emitted that effects the health of nearby residents. In addition, homes that had greater air infiltration (via envelope airtightness measurements) had elevated levels of particulate matter – the pollutant most associated with transportation proximity. This thesis provides a basis for further investigations in this ongoing project and for similar asthma and air quality relationship studies.
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- Title
- 3D reconstruction of lake surface using camera and lidar sensor fusion
- Creator
- Khan, Shahrukh
- Date
- 2020
- Description
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Global Navigation Satellite System Reflectometry (GNSS-R) relies upon detecting the GNSS signals reflected off a surface and then analyzing...
Show moreGlobal Navigation Satellite System Reflectometry (GNSS-R) relies upon detecting the GNSS signals reflected off a surface and then analyzing the reflected signal to obtain surface characteristics. GNSS-R has become one of the many additional applications of the readily available GNSS signals, alongside more traditional remote sensing of ionospheric monitoring, beyond the intended GNSS purposes of providing position, navigation, and timing estimation. In previous work, GPS signals reflected off Lake Michigan in Chicago have been collected using a specially designed portable sensor suite. The data collected is then analyzed to differentiate between surface ice and water conditions, as well as obtain other characteristic information such as surface reflectivity. The goal is to provide a way for remote sensing of seasonal ice formation beyond just satellite imagery which can be affected by cloud cover. To confirm the validity of the GNSS-R results there needs to be a separate reference against which to compare. This work demonstrates the sensor fusion between camera and lidar to reconstruct the lake surface, to provide that truth reference for comparison against the results of the GPS reflectometry signal processing. For this setup, the camera provides visual information about the lake surface, while the lidar provides distance information with respect to the sensor suite. Combining the data from the two sensors allows backward projection of the camera image to reconstruct the lake surface and its features. The backward projection relies upon knowledge of the camera's intrinsic properties alongside distance information of the features captured by the camera. Each pixel of the camera image is then transformed to its 3D position relative to the sensor system. This produces a 3D map of the lake surface, as captured by the sensors. The estimated point at which the GPS signal reflects off the surface, the specular point, is calculated by the satellite position at the time of interest and the receiver location. This point is then mapped onto the reconstructed surface to identify the exact location where the signal reflected and compare the surface visually to the results from the signal analysis.Time-varying camera-lidar-specular-point maps of the data campaigns conducted for this project are created for comparison with the GPS signal analysis. Multiple data campaigns were performed during which the Lake Michigan surface had surface ice, water or a mixture of the two. The lake surface is reconstructed for different timestamps, using the appropriate image frame and lidar frame. Combining chronologically, the changes in the lake surface can then be observed along with the movement of the specular point, due to the movement of the GPS satellites. Any satellites passing over a boundary between water and ice on the lake surface are identified and time stamped, to then be compared to the GPS signal analysis results.
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- Title
- Gaussian Process Assisted Active Learning of Physical Laws
- Creator
- Chen, Jiuhai
- Date
- 2020
- Description
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In many areas of science and engineering, discovering the governing differential equations from the noisy experimental data is an essential...
Show moreIn many areas of science and engineering, discovering the governing differential equations from the noisy experimental data is an essential challenge. It is also a critical step in understanding the physical phenomena and prediction of the future behaviors of the systems. However, in many cases, it is expensive or time-consuming to collect experimental data. This article provides an active learning approach to estimate the unknown differential equations accurately with reduced experimental data size. We propose an adaptive design criterion combining the D-optimality and the maximin space-filling criterion. The D-optimality involves the unknown solution of the differential equations and derivatives of the solution. Gaussian process models are estimated using the available experimental data and used as surrogates of these unknown solution functions. The derivatives of the estimated Gaussian process models are derived and used to substitute the derivatives of the solution. Variable-selection-based regression methods are used to learn the differential equations from the experimental data. The proposed active learning approach is entirely data-driven and requires no tuning parameters. Through three case studies, we demonstrate the proposed approach outperforms the standard randomized design in terms of model accuracy and data economy.
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- Title
- THE MODERATING AND MEDIATING ROLE OF SELF-REPORTED FAMILY ACCOMMODATION ON THE RELATION BETWEEN OBSESSIVE-COMPULSIVE SYMPTOMS AND RELATIONSHIP SATISFACTION IN AN ADULT, CLINICAL SAMPLE OF INDIVIDUALS IN ROMANTIC RELATIONSHIPS
- Creator
- De Leonardis, Andrew J
- Date
- 2020
- Description
-
Severity of obsessive-compulsive symptoms (OCS) is associated with treatment resistance, and in an interpersonal context, is associated with...
Show moreSeverity of obsessive-compulsive symptoms (OCS) is associated with treatment resistance, and in an interpersonal context, is associated with increased relationship distress and decreased relationship satisfaction. In addition, caregivers for those with clinical levels of OCS often engage in family accommodation (FA) behaviors that serve as an extension of the OCD patient’s compulsive behavior. However, the literature on the interchange of OCS, FA, and relationship satisfaction is limited in scope because it focuses mainly on the perspective of the caregiver or partner of the individual with OCD. The current study aims to address this limitation by examining OCS, FA, and relationship satisfaction variables from the perspective of the individual with OCD. Participants included 78 adults with self-reported OCD who were recruited in the US through clinics and clinicians specializing in OCD treatment, as well as from OCD non-profit organizations to target non-treatment-seeking participants. After controlling for demographic variables, results indicated the following: (1) a significant positive association between OCS and FA, (2) a significant negative association between OCS and relationship satisfaction, and (3) a lack of an interaction between FA and OCS when predicting relationship satisfaction. However, the third result was trending towards significance and may be statistically underpowered. Exploratory analyses found FA to be a partial mediator of the association of OCS and relationship satisfaction. The findings support current trends in the research literature as well as contradict extant research on the associations between OCS, FA, and relationship satisfaction. Additionally, findings continue to show the importance of addressing family accommodation in treatment of individuals with OCD.
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- Title
- Evaluation of Salmonella Proliferation on Alfalfa Sprouts during Storage at Different Temperatures
- Creator
- Lin, Chih Tso
- Date
- 2020
- Description
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Sprouts, a low-calorie vegetable rich in nutrition, have been a popular ingredient in many meals in the USA. They are grown either at...
Show moreSprouts, a low-calorie vegetable rich in nutrition, have been a popular ingredient in many meals in the USA. They are grown either at commercial sprout farms or at home and served raw or lightly cooked. However, sprouts are also known as a source of foodborne illness outbreaks. FDA Food Code identifies raw sprouts as a time/temperature control for safety food. However, little information is known about the growth profile of foodborne pathogens in sprouts stored at different temperatures. This study aimed at evaluating the proliferation of Salmonella in alfalfa sprouts during storage at 4, 10, and 25℃ under two different contamination routes: 1) sprouts that were inoculated with Salmonella after harvest and 2) sprouts that were grown from contaminated seeds. Alfalfa sprouts grown from uninoculated seeds and harvested after 5 days of sprouting were divided into 25-g portions. Each portion was inoculated with a cocktail of five Salmonella serovars at levels of 10^1, 10^3 or 10^5 CFU/g prior to storage at 4, 10, or 25℃. Alternatively, sprouts grown for five days from seeds spiked with 1% of seeds previously inoculated with the Salmonella cocktail were divided into 25-g portions and stored at 4, 10, or 25℃. At defined time points (Days 0, 2, 4, 7, 14, and 21), levels of Salmonella and background microflora in stored sprouts were determined by plate count. Alfalfa sprouts appeared fresh during the 21 days of storage at 4 or 10℃ but started to show signs of spoilage after 4 days of storage at 25℃. The total plate counts maintained at a level above 9 log CFU/g throughout 21 d of storage at 4 and 10℃ or during the first 7 d of storage at 25℃. Storing sprouts at 4 or 10℃ could inhibit the proliferation of Salmonella. After 21 d of storage, the Salmonella counts in inoculated sprouts decreased slightly, by 0.88 or 0.93 log units, respectively. For sprouts stored at 25℃, the Salmonella growth profile differed depending on the route of contamination and the level of Salmonella at the start of storage. In sprouts inoculated at levels of 1.41, 2.83, and 4.75 log CFU/g, the Salmonella counts increased to 6.62, 6.86, and 6.68 log units, respectively, during the first 4-7 days of storage. For alfalfa sprouts grown from contaminated seeds, the Salmonella counts remained at a level similar to that in the harvested sprouts (8.16 log CFU/g) during the first 7 d. Results from this study further the understanding of pathogen growth in sprouts and will aid in the development of guidelines for proper storage of sprouts.
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- Title
- Ultraviolet photo-chemical degradation of polyethylene terephthalate for use as an alternative recycling method
- Creator
- Smith, Andrew Thomas
- Date
- 2020
- Description
-
Consumer plastics are a deeply integrated part of the modern world. Their inherent properties which make them cheap, durable, moldable, and...
Show moreConsumer plastics are a deeply integrated part of the modern world. Their inherent properties which make them cheap, durable, moldable, and versatile have caused plastics to be used in many consumer products available for market. However, these same properties have made them a detriment to local and global environments. plastic has begun accumulating in the world’s waterways and oceans, leading to severe ecological consequences. Polyethylene terephthalate (PET) is one of the most pervasive consumer plastic, and a large contributor to the amount of waste. Because of its prevalence in the market, PET has been the focus of research into its recycling and reuse. However, all methods face issues of profitability due to operation and equipment costs, preventing widespread recycling of plastic waste. This leaves the door open to explore other processes of plastic recycling.In this study, ultraviolet photo-chemical degradation of PET was explored as an alternate route to plastic recycling. Ultraviolet irradiation has long been known to depolymerize PET plastic products, but has not been studied in order to enhance these effects. This method has the potential to reduce operation and equipment costs associated with traditional chemical recycling methods by carrying out depolymerization in the solid state. By harnessing this process, PET could be used to degrade material down to a state usable in in other, higher value products. An irradiation chamber was built as a preliminary prototype. This chamber used light of a specific ultraviolet wavelength determined from the absorbance spectrum of PET samples. This allowed the irradiation to be safer, while still maintaining absorption.Ultraviolet degradation of PET was first examined using infrared, contact angle, and fluorescence analysis, and birefringence observation to analyze the chemical and surface effects of irradiation. The results were used to understand the complex mechanisms behind the photo-chemical degradation process. Results were then discussed alongside similar experiments performed in the literature for a deeper understanding of the underlying mechanism.The molecular weight of exposed bottle samples was evaluated using both viscosity and dynamic light scattering methods. This information is key, as it is the main metric that determines the success of the process. In addition, the ultraviolet absorbance of the sample was analyzed along with the principles of Beer’s law. This yielded quantitative analysis on the effect of thickness of the sample, the degradation rate, and the quantum yield of the process.Finally, building upon the information gathered in the study, two key process modifications are made. Thinner samples are first produced, and receive irradiation on both surfaces. The degradation of the modified process was compared to that of previous results on the basis of molecular weight reduction, reaction rate and quantum yield. Using these results, conclusions were drawn about using ultraviolet photo-chemical degradation as a recycling process.
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- Title
- Developing Leader Identity via Structured Reflection
- Creator
- Standish, Melanie P.
- Date
- 2020
- Description
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As leader identity research in the context of leader development continues to expand, it is important to understand the mechanisms through...
Show moreAs leader identity research in the context of leader development continues to expand, it is important to understand the mechanisms through which leader identity becomes more central to one’s self concept. Structured leadership reflection is proposed to positively impact leader development but has not been experimentally manipulated to understand what its impact is on leader identity change. In this study, 90 participants were assigned into one of three reflection conditions and were asked to respond to reflection prompts over the course of four days. Participants were divided into the control condition, the reflecting on others as leaders condition, or the reflecting on oneself as a leader condition. Results showed no significant differences between reflection groups and their impact on leader identity change. Though our results do not provide support for the use of structured reflection to elicit leader identity development, we suggest future research should further study structured self-reflection over a longer period of time.
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- Title
- GROWTH KINETICS OF LISTERIA MONOCYTOGENES DURING REHYDRATION OF DEHYDRATED PLANT FOODS AND SUBSEQUENT STORAGE
- Creator
- Wu, Zihui
- Date
- 2020
- Description
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Dehydrated plant foods do not support the growth of pathogenic bacteria. However, once rehydrated, the high-water activity and neutral pH of...
Show moreDehydrated plant foods do not support the growth of pathogenic bacteria. However, once rehydrated, the high-water activity and neutral pH of these foods may support the growth of pathogens, such as L. monocytogenes, during storage. The goal of this study was to examine the growth kinetics of L. monocytogenes during 5, 10, and 25°C storage on potatoes, carrots, and onions after rehydration with 5 or 25°C water. Fresh plant foods were dehydrated at 140°F (60°C) for 24 h. A 4-strain rifampicin-resistant L. monocytogenes cocktail was inoculated onto dehydrated plant foods at 4 log CFU/g and dried for 24 h. Plant foods were rehydrated in 4-volumes of 5 or 25°C water for 24 h. At various timepoints during rehydration, 30 g of sample was removed and drained for 10 min. Samples were homogenized 1:10 with BLEB and the homogenate was plated onto BHIRif for enumeration. After rehydration, samples were drained and portioned into deli-style containers for storage at 5, 10, and 25°C and L. monocytogenes was enumerated at 1, 3, 5, and 7 d. Triplicate samples were assessed at each timepoint and three independent trials were conducted. Growth rates were determined using DMFit and data were statistically analyzed using Student t-test (α=0.05). Overall, the growth rates of L. monocytogenes during storage of potatoes and carrots were higher when rehydrated with 5°C water compared to 25°C water. The highest growth rate on potatoes was 3.51±0.43 log CUF/g per d with 5°C water rehydration and 25°C storage, resulting in a 1 log CFU/g increase in 0.29 d (7.0 h). When rehydrated with 25°C water and 25°C storage, the growth rate was significantly lower at 1.03±0.01 log CFU/g per d. The highest growth rate of L. monocytogenes on carrots was 0.68±0.07 log CUF/g per day when rehydrated with 5°C water and 10°C storage, resulting in a 1 log CFU/g increase in 1.47 d (35.3 h). For onion, L. monocytogenes was below the level of enumeration during storage at 5°C for both water rehydration temperatures and also for 10°C storage with 5°C water rehydration. The highest growth rate was 0.46±0.11 log CFU/g per d, resulting in a 1 log CFU/g increase in 2.17 d. The results of this study can aid in determining appropriate time and temperature control for safety for dehydrated potatoes, carrots and onions during rehydration and subsequent storage.
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- Title
- IMPACT OF DATA SHAPE, FIDELITY, AND INTER-OBSERVER REPRODUCIBILITY ON CARDIAC MAGNETIC RESONANCE IMAGE PIPELINES
- Creator
- Obioma, Blessing Ngozi
- Date
- 2020
- Description
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Artificial Intelligence (AI) holds a great promise in the healthcare. It provides a variety of advantages with its application in clinical...
Show moreArtificial Intelligence (AI) holds a great promise in the healthcare. It provides a variety of advantages with its application in clinical diagnosis, disease prediction, and treatment, with such interests intensifying in the medical image field. AI can automate various cumbersome data processing techniques in medical imaging such as segmentation of left ventricular chambers and image-based classification of diseases. However, full clinical implementation and adaptation of emerging AI-based tools face challenges due to the inherently opaque nature of such AI algorithms based on Deep Neural Networks (DNN), for which computer-trained bias is not only difficult to detect by physician users but is also difficult to safely design in software development. In this work, we examine AI application in Cardiac Magnetic Resonance (CMR) using an automated image classification task, and thereby propose an AI quality control framework design that differentially evaluates the black-box DNN via carefully prepared input data with shape and fidelity variations to probe system responses to these variations. Two variants of the Visual Geometric Graphics with 19 neural layers (VGG19) was used for classification, with a total of 60,000 CMR images. Findings from this work provides insights on the importance of quality training data preparation and demonstrates the importance of data shape variability. It also provides gateway for computation performance optimization in training and validation time.
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- Title
- REVEALING LINGUISTIC BIAS
- Creator
- Karmarkar, Sathyaveer S.
- Date
- 2021
- Description
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Readers currently face bias in articles written by writers who focus more on partiality towards any person or organization than showing the...
Show moreReaders currently face bias in articles written by writers who focus more on partiality towards any person or organization than showing the real facts. The study aims to detect and reveal such bias against them and try to portray real facts without any partiality against any person or organization. The data is fetched by selecting various articles from Google, especially those containing some bias in them. The bias was checked by measuring the subjectivity and polarity of the article using multiple libraries such as NLTK etc. We created a google form to take readers’ views showing them randomly either the biased article or the improved article after changing bias and getting their opinions.
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- Title
- Effects of the Silicon Content on the Dimensional Changes of Electrodes for Lithium-ion Cells: An Electrochemical Dilatometry Study
- Creator
- Rodrigues Prado, Andressa Yasmim
- Date
- 2021
- Description
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The continuous growth of the electric vehicle market has significantly increased the demand for Li-ion batteries (LIBs). However, state-of-the...
Show moreThe continuous growth of the electric vehicle market has significantly increased the demand for Li-ion batteries (LIBs). However, state-of-the-art LIBs are not yet able to meet the EV industry demand for high energy density and long cycle life rechargeable batteries, prompting efforts to improve the performance of Li-ion cells. In this context, silicon became the most promising next-generation active material for LIBs negative electrodes, especially because Si can significantly increase the lithium storage capacity of the commonly available anodes. Nonetheless, commercialization of Si-based electrodes has been hindered by the poor electrochemical performance of these electrodes, which is mainly attributed to the severe volumetric changes in the silicon particles related to the electrochemical reactions with Li. Since the electrodes are composites with a complex combination of various materials interspaced by pores, the electrode-level swelling may differ significantly from the particle-scale expansion. Furthermore, an increase in electrode thickness due to silicon expansion can have a direct effect on how Li-ion cells are designed, as the accommodation of electrode dilation requires additional cell space to prevent significant dynamic stresses. Thus, the actual volumetric energy density of a LIB cell depends on the electrode swelling, since the higher the magnitude of the electrode expansion, the lower the gains in energy density. Monitoring the electrode dilation is just as important as the electrochemical evaluation when designing cells with Si-based anodes.In this work, we use high-resolution operando electrochemical dilatometry to quantify the (de)lithiation-induced expansion/contraction of silicon, blended silicon-graphite and graphite electrodes, upon electrochemical cycling. We evaluate the relationship between electrode capacity and dilation and observe that while the lithiation capacity improved with increasing the silicon content, the electrode swelling is highly aggravated. For silicon-rich anodes, the electrode dilation can be higher than 300%, and the expansion profile consists of a combination of slow swelling at low levels of lithiation followed by an accelerated increase at higher lithium contents. This non-linear dilation allows for narrowing the swelling by limiting the electrode capacity. In addition, we investigate how electrode properties, such as porosity, affect the dilation profile, and quantify the irreversible expansion of the electrodes. Finally, we discuss some of the challenges associated with the dilatometry technique and suggest experimental approaches for obtaining consistent and reliable data.
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- Title
- MITOCHONDRIA RELOCALIZATION IN CHLAMYDIA TRACHOMATIS INFECTED HFF-1 CELLS
- Creator
- Shuppara, Alexander Mitchell
- Date
- 2021
- Description
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Chlamydia trachomatis is an infectious, gram-negative, obligate intracellular human bacterial pathogen. With over eight hundred million cases...
Show moreChlamydia trachomatis is an infectious, gram-negative, obligate intracellular human bacterial pathogen. With over eight hundred million cases worldwide, C. trachomatis is the most prevalent sexually transmitted infection. It manifests as either trachoma, lymphogranuloma venereum, or other urogenital tract sequelae. As an intracellular pathogen, Chlamydia must scavenge for essential metabolites from establishing networks with its host’s organelles including Golgi apparatus, endoplasmic reticulum, endocytic vesicles, mitochondria, and the cytoskeleton. C. trachomatis was considered an “energy parasite” that is entirely dependent on their host’s ATP production. Yet, recent mitochondrial inhibitor-based evidence suggests that C. trachomatis possess a sodium-based energy gradient for ATP production. Despite this finding, literature on specific interactions between host cell mitochondria and C. trachomatis requires further definition. This project evaluates mitochondrial dynamics changes from C. trachomatis infection in the human foreskin fibroblast cell line, HFF-1. We first defined C. trachomatis growth characteristics in HFF-1 over 36 hours-post infection. Next, we determined changes in mitochondrial dynamics and content throughout infection using immunofluorescent and immunoblotting techniques. observations on infected cells show mitochondrial morphology changes from an elongated appearance at the early stages of infection to fragmented in the late infection stages. Unlike in HeLa cells, HFF-1 remains in a normal distribution throughout the cell and we do not observe mitochondria relocalizing toward the inclusion. By studying mitochondrial relocalization dynamics, new insights into the dynamic and parasitic relationship of Chlamydia and its host can be discovered.
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- Title
- Understanding the effect of temperature, strain and grain size on the stress relaxation behavior of Ni-base and steel alloys
- Creator
- Reny, Julia
- Date
- 2021
- Description
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Stress relaxation research is very valuable as it provides information on how materials relieve stress under a constant strain. In...
Show moreStress relaxation research is very valuable as it provides information on how materials relieve stress under a constant strain. In applications where parts are submitted to a constant deformation, it is important to know that regions containing notches or stress concentrations will be able to relax enough to avoid the formation of cracks during operations. In this study, the stress relaxation behaviors of experimental Ni-base superalloy RRHT5 and Pyrowear 53 steel alloy were investigated. Tests were conducted under different conditions, varying temperature, initial strain, and grain size to explore the influence of each of these factors. The stress relaxation test data was used to calculate apparent activation volumes which can be correlated with plastic deformation mechanisms governing the stress relaxation. Understanding these mechanisms and identifying how specific factors influence them is essential to further control and optimize the design and processing of materials to obtain the best properties. Depending on the test conditions, the stress relaxation underwent one or two stages dominated by different mechanisms. These governing mechanisms were considered to be either dislocation-dislocation interactions, dislocation rearrangement, dislocations spreading from localized slip bands or dislocation-precipitate interactions.
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- Title
- HERBS AND SPICES ON ENDOTHELIAL FUNCTION OVER 24 HOURS: A RANDOMIZED, CONTROLLED TRIAL
- Creator
- Thorat, Rajrajeshwari Sunil
- Date
- 2021
- Description
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Modern-day eating patterns are characterized by readily available carbohydrates and/or fats and have consistently been shown to disturb...
Show moreModern-day eating patterns are characterized by readily available carbohydrates and/or fats and have consistently been shown to disturb endothelial function. Recent investigations suggest herb and spice blends have beneficial effects in reducing inflammation and increasing endothelial function in humans. This study was designed to characterize the effect of herbs and spices on endothelial function as measured by flow-mediated dilation (FMD) over 24 h using a challenge meal paradigm. In a randomized, single-blinded, 4-arm, crossover trial, sixteen overweight/obese adults (BMI = 28.4 ± 2.5 kg/m2; age = 39 ± 15 years) consumed a high carbohydrate high-fat meal (≈ 41% Fat and ≈46% Carbohydrate of total Kcal) with or without the spices combinations, including Italian herbs (rosemary, basil, thyme, oregano, and parsley), cinnamon, and pumpkin pie spice (cinnamon, ginger, nutmeg, and allspice) on four separate days at least three days apart. Meals provided to subjects were customized according to the individual's energy needs to maintain the body weight. The meal was composed of 35% of the daily estimated energy requirement. FMD was performed at 0, 1, 2, 4, 5.5, 7, and 24h. A pressure cuff was positioned below the elbow, artery diameter was measured before the pressure is applied and then inflated to 220 mmHg systolic pressure for 5 minutes. Immediately after cuff deflation, brachial artery vessel diameter was measured to obtain peak vessel relaxation. FMD was calculated as a percentage change in artery diameter before and after the release of the pressure. Baseline (t= 0 h) %FMD change was not significantly different between the treatments (p>0.05). There was no significant increase in the %FMD after consuming the control meal at all time points (p>0.05). Consumption of meals with Italian herb mix, cinnamon, and pumpkin pie spice significantly increased %FMD at 24 h compared to the control meal (mean ± standard error at 24 h, 7.83 ±0.89%, 7.98±0.95% and 8.44±0.70% vs 6.03±0.79%, respectively, p˂0.05). Furthermore, % FMD was significantly increased at t= 24h in Italian herb mix and cinnamon compared to their respective baselines 5.68 ± 0.37% to 7.83 ± 0.89% (p=0.01) and 6.43 ± 0.89% to 7.89 ± 0.95% (p=0.03), respectively. The results of this research indicate that spices may be beneficial for improving endothelial function after 24 h consumption, suggesting bioactivity of herbs and spices on endothelial function will be related to their time course of bioavailability of bioactive components. This was the first study that assessed the effect of herbs and spices over 24 hours using FMD. Understanding the mechanism of how these herbs and spices improve endothelial function will be the subject of future research.
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- Title
- Eating Pathology Among Ethnic Subgroups of Latinas: An Examination of Acculturative Stress and Ethnic Identity
- Creator
- Quinones, Isabel Cristina
- Date
- 2021
- Description
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Latin women (Latinas) in the U.S may experience acculturative stress if ethnic group pressures regarding body ideals differ from the U.S. body...
Show moreLatin women (Latinas) in the U.S may experience acculturative stress if ethnic group pressures regarding body ideals differ from the U.S. body ideal. As a population consisting of multiple countries, the distinct cultures and customs among subgroups may impact how women from heterogeneous Latino countries/cultures perceive acceptable body weight and shape, as body ideals are culturally constructed. Furthermore, an individual’s ethnic identity level may impact the way acculturative stress relates to eating pathology. This study investigated 1) acculturative stress as a mediator of the relationbetween ethnic group and eating pathology among specific Latina subgroups, and 2) ethnic identity as a moderator of the association between ethnic group and acculturative stress, acculturative stress and eating pathology, and ethnic group and eating pathology. Mexican (n=30), Puerto Rican (n=31), Cuban (n=29), and non-Hispanic, White (n=30) women living in the U.S. were recruited via Prolific Academic to complete self-report questionnaires regarding ethnic group, ethnic identity level, acculturative stress, and eating pathology. Moderated mediation analyses supported a significant indirect effect of ethnic group on body dissatisfaction, binge eating, purging, restricting, excessive exercise, and negative attitudes towards obesity through acculturative stress, such that group differences were mediated by acculturative stress levels. Further, the association between acculturative stress and body dissatisfaction was dependent on strength of ethnic identity; there was a positive simple slope for women with low and moderate levels of ethnic identification (low b = 2.30, moderate b = 1.36, both p <0.001) but not for those with high ethnic identity (b = 0.52, p = 0.22), suggesting that a higher ethnic identification may be protective against the development of body dissatisfaction in Latinas experiencing acculturative stress. Findings support the importance of separating heterogeneous subgroups of Latinas and explicitly assessing acculturative stress. Assessment and preventive action should include addressing increased acculturative stress and the risk it may pose for Latinas endorsing eating pathology given that the combination of ethnic group, acculturative stress, and ethnic identity may pose an increased risk for Latina individuals vulnerable to eating pathology.
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- Title
- POTENTIAL EXPOSURE TO SUBSTANCES IN POLYMER COMPOSITES USED AS FOOD PACKAGING MATERIALS
- Creator
- Shah, Saloni S.
- Date
- 2021
- Description
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In the food manufacturing, preservation, supply, and distribution chain, packaging plays a critical role. The fundamental goal of any...
Show moreIn the food manufacturing, preservation, supply, and distribution chain, packaging plays a critical role. The fundamental goal of any packaging method is to keep food contained and protected. There is an increasing demand for natural and "fresh-like" foods that are less processed and have a longer shelf life, necessitating a variety of packing strategies. With increasing demand, the biggest developments in the field of packaging technology have been innovative food packaging approaches, such as active packaging, intelligent packaging, and bioactive packaging, which include deliberate contact with the food or its surroundings and its effect on consumer health. Several research studies in the past few years have shown that nanocomposite materials have significant improvement in the strength, barrier characteristics, antimicrobial capabilities, and heat and cold stability of food packaging materials, but various studies have reported that these composites might be a source of engineered nanomaterials in the human diet or environment. It has also been reported in numerous studies that nanocomposites can migrate into the food during long-term storage. These studies use food simulants like acetic acid and water to mimic the food matrix. However, they raise issues regarding how ingredients in real foods could affect exposure. This research focuses on the migration of silver (Ag) ions into food matrix-like commercial beverages and demonstrating if the ingredients present in commercial food and beverages influence the migration process. For the study, polymer composites films and dogbones were made. Polymer composite films with 0.2%, 1%, and 5% of silver zeolite concentration in polylactic acid (PLA) were produced, and different media like water, Domino sugar, and Squirt were stored in packages manufactured from this material under accelerated room-temperature conditions. Polymer composite dogbones were made with low-density polyethylene (LDPE) and polypropylene (PP) with 1.25% and 2.51% of graphene and graphite. Further, these materials were characterized with the help of Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy-Attenuated Total Reflection (FTIR-ATR), and inductively coupled plasma mass spectrometry (ICPMS). This hypothesis of this study was that, when polymer composites are employed in packaging applications, food and beverage components may impact dietary exposure to these particles, and the use of food simulants may underpredict the quantity of the migration in some cases
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- Title
- HIGH SURFACE AREA CARBONS FOR ENERGY STORAGE TECHNOLOGIES
- Creator
- Lee, Youngjin
- Date
- 2021
- Description
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Energy storage systems play a pivotal role in harvesting energy from various sources and converting it to the energy forms required for...
Show moreEnergy storage systems play a pivotal role in harvesting energy from various sources and converting it to the energy forms required for applications in several sectors, such as utility, industry, building and transportation. The outstanding growth of portable electronic devices and electric vehicle/hybrid electric vehicles (EVs/HEVs) has promoted the urgent and increasing demand for high‐power energy resources. The most common electrical energy‐storage device is the battery due to the large amount of energy stored in a relatively small volume and weight while providing suitable levels of power for many applications and requirements of everyday life. These days, lithium-sulfur batteries (LSBs) have been drawing attention with their potential to provide 3-5 times more energy than that of current lithium-ion batteries (LIBs) at lower cost. Thus, realization of a practical Li-S technology can move the U.S. rapidly toward a more sustainable transportation future. The electrochemical double-layer capacitor (EDLC) is also an emerging technology, which really plays a key part in fulfilling the demands of electronic devices and systems, for present and future. The EDLC technology strongly depends on the properties of electrode materials. Activated carbons play an important role in developing new electrodes for both LSB and supercapacitor technologies. For example, carbon electrode-based supercapacitors require very high specific surface area and superior pore size distribution for easy accessibility of ions. Thus, the primary objective of this study is to develop a new high surface area carbon material and assess its applicability for both LSB and supercapacitor technologies. In this thesis work, we have designed and synthesized several active carbon materials. One of them displayed very high surface area (1,832 m2/g) and excellent pore diameter (3.6 nm). We investigated the applicability of this carbon material for supercapacitor electrodes. We have also modified this carbon material with a nickel-rich phosphide in order to make it suitable for LSB cathode applications.
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- Title
- ENERGY METABOLISM OF CHLAMYDIA PNEUMONIAE
- Creator
- McMillan, B. Julia
- Date
- 2021
- Description
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Chlamydia pneumoniae is a gram-negative bacterium that infects the humanrespiratory tract. It causes acute pneumonia and has been linked to...
Show moreChlamydia pneumoniae is a gram-negative bacterium that infects the humanrespiratory tract. It causes acute pneumonia and has been linked to several chronic diseases including cardiovascular disease, asthma, and some neurological diseases. C. pneumoniae primarily exists in two forms, the elementary body (EB) and the reticulate body (RB). The EB infects host cells and the RB replicates inside them. In order to survive in and out of the host, it was thought that C. pneumoniae RBs obtain host ATP to use for energy, making it an “energy parasite.” However, genomic analysis indicated that it was also possible for C. pneumoniae to create ATP from its own respiratory chain using the Na + pump NADH Ubiquinone Oxidoreductase (Na + -NQR). Neither the details of the energy parasite theory nor the possibility of C. pneumoniae creating its own energy had been experimentally explored. This project used a pharmacological approach to explore C. pneumoniae host energy consumption at various developmental stages, examine a mechanism that the bacterium could use to produce its own energy, and assess the importance of a balanced Na + /H + gradient for energy production and maintaining homeostasis. Based on the genomic analysis, it was thought that C. pneumoniae would rely heavily on host ATP in the EB form but not the RB form, that inhibiting Na + -NQR would slow bacterial growth, particularly in RBs, and that disrupting the Na + /H + gradient would significantly reduce RB infection. The results indicate that in the EB form, C. pneumoniae relies on host ATP and requires a balanced Na + /H + gradient, but disrupting Na + -NQR does not hinder its growth. In the RB form, C. pneumoniae is not dependent on host ATP, nor on its own respiratory chain ATP, and is not impacted by an unbalanced Na + /H + gradient. Therefore, the energy parasite hypothesis appears to apply to C. pneumoniae EBs but not RBs. Furthermore, established C. pneumoniae infections are excellent at compensating for various environmental conditions and sources of energy, which proves challenging for drug design against C. pneumoniae.
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