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Title: H1 LUBRICANT TRANSFER FROM A HYDRAULIC PISTON FILLER INTO A SEMI-SOLID FOOD SYSTEM
Creator: Chao, Pin-Chun
Date: 2020
Description: The machinery used to prepare, and process food products need grease and oil for the lubrication of machine parts. H1 (food-grade) lubricants...
Show moreThe machinery used to prepare, and process food products need grease and oil for the lubrication of machine parts. H1 (food-grade) lubricants commonly used in the food industry are regulated as indirect additives by the FDA because they may become components of food through transfer due to incidental contact between lubricants and foods. The maximum level of H1 lubricants currently permitted in foods is 10 ppm, which was derived from FDA data gathered over 50 years ago. Although modern equipment has been designed to minimize the transfer of lubricants during processing and packaging, incidental food contact can still occur resulting from leaks in lubrication systems or over-lubrication. However, there is a lack of data for the FDA to evaluate and determine whether safety issues in the aspect of chemical contamination should be addressed concerning the use of food-grade lubricants in the production of foods. This research was conducted to determine the transfer of an H1 lubricant (Petrol-Gel) into a semi-solid model food from a hydraulic piston filler during conventional operating conditions at 25°C and 50°C. Xanthan gum solutions with concentrations of 2.3% at 25°C and 1.9% at 50°C were used to simulate the viscosity of ketchup at 50°C (970 cP). Petrol-Gel H1 lubricant with a viscosity grade of 70 cSt at 40°C was selected and the aluminum (Al) in the lubricant was targeted as a tracer metal. Analytical methods to quantify Al in both Petrol-Gel and xanthan gum solutions were successfully developed and validated by using inductively coupled plasma – mass spectrometry (ICP-MS) combined with microwave-assisted acid digestion technique. The concentration of Al in the Petrol-Gel was determined to be 3103 ± 26 μg/g. A total of 1.35 g of Petrol-Gel was applied to four ring gaskets in the filler, and 50 g samples of xanthan gum solution were collected into a 100-mL polypropylene tube (DigiTube) with low leachable metals during 500 filling cycles (the full capacity of the piston filler hopper).Results showed that the concentrations of Petrol-Gel transferred into 2.3% xanthan gum solution at 25°C ranged from 1.6 to 63.5 μg/g. A total of 64.47 mg of the applied Petrol-Gel (1.35 g) was transferred into 25 liters of the solution. The average concentration of Petrol-Gel in 2.3% xanthan gum solution was calculated to be 2.84 μg/g, which was lower than the current regulatory limit of 10 ppm. In general, the transfer of Petrol-Gel during the first 100 filling cycles was higher at 50°C than at 25°C. The concentration of Petrol-Gel transferred into 1.9% xanthan gum solution at 50°C for the first 100 filling cycles ranged from 1.6 to 35.06 μg/g and was 6.37 μg/g on average. This research will help FDA to calculate more realistic limits of the H1 lubricants permissible in foods at modern food processing conditions as well as estimate consumer dietary exposure to these indirect food additives.
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Title: AMPLIFICATION AND PURIFICATION OF RECOMBINANT PRO-DEATH BAXΔ2 PROTEINS FOR STRUCTURE ANALYSIS
Creator: Zhou, Yi
Date: 2020
Description: BaxΔ2 is an isoform of the pro-apoptotic Bax family of proteins, which is an important anti-cancer protein. BaxΔ2 behaves differently from...
Show moreBaxΔ2 is an isoform of the pro-apoptotic Bax family of proteins, which is an important anti-cancer protein. BaxΔ2 behaves differently from Baxα to induce apoptosis. The current computationally predicted model of BaxΔ2 is based on known Baxα structure, which is considered biased. Therefore, the elucidation of the BaxΔ2 crystal structure is critical. The goal of this project was to obtain a sufficient amount of purified recombinant Bax∆2 protein for crystallization. We cloned full-length BaxΔ2 fused with a poly-histidine tag on either N-terminus (His-Bax∆2) or C-terminus (Bax∆2-His) into an inducible bacterial expression vector. We found that His-Bax∆2 proteins were expressed better than Bax∆2-His, which totally inhibit host growth. However, the protein concentration of His-Bax∆2 was still too low to be detected by Coomassie blue staining. To increase His-Bax∆2 expression and avoid cytotoxicity, we further tested different bacterial host cells and applied the chaperone system. However, all attempts could not overcome Bax∆2 cytotoxicity and the protein expression levels were not high enough to be feasible for further large-scale purification. The mechanism underlying how Bax∆2 inhibits bacterial growth is still a mystery because Bax∆2 eukaryotic targets (mitochondria and caspases) do not exist in bacteria. Further experiments are required to explore the mechanism of Bax∆2 cytotoxicity in bacteria, so as to finally optimize and elevate the BaxΔ2 protein yields.
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Title: IMAGE-ANALYSIS WITH FIJI PROGRAM ON PERIPHERAL BLOOD MONOCULAR CELLS AFTER CONSUMPTION OF HIGH-FAT, HIGH CARBOHYDRATE MEAL WITH OR WITHOUT ADDITION OF SPICES – A SINGLE-CENTER RANDOMIZED, BLINDED, PLACEBO-CONTROLLED, 4-ARM, 24HR ACUTE CROSSOVER STUDY
Creator: Tsai, Meng Fu
Date: 2020
Description: Chronic low-grade inflammation plays a significant role in developing various chronic diseases, such as cardiovascular disease and type II...
Show moreChronic low-grade inflammation plays a significant role in developing various chronic diseases, such as cardiovascular disease and type II diabetes. Western-type diets characterized by high-fat (saturated fat) and high-carbohydrate (HFHC) calories induce oxidative stress leading to inflammation. Polyphenol rich foods, such as berries, tea, and herbs and spices, have antioxidant properties. Spices have been shown to have anti-inflammatory effects in cell and animal studies; however, data are limited in humans. In the present study, we hypothesized that bioactive polyphenolic compounds in herbs and species would reduce diet-induced inflammation in overweight and obese (OW/OB) individuals. In a randomized, single-blinded 4-arm, 24-h, crossover clinical trial, sixteen OW/OB adults consumed an HFHC meal with and without three herbs and spices combinations, including Italian herbs (rosemary, basil, thyme, oregano, and parsley), cinnamon and pumpkin pie spice (cinnamon, ginger, nutmeg, and allspice) on four separate occasions at least three days apart. Markers of inflammation were assessed before and at 2, 4, 5.5, and 7 hours after meal consumption by tracking nuclear translocation of nuclear factor kappa B (NF-κB), a transcription factor in inflammatory signaling, in human peripheral blood monocular cells (PBMCs) and by measuring plasma interleukin-6 (IL-6), a pro-inflammatory cytokine. Nuclear translocation of NF-κB and the proportion of PBMCs activated were estimated through a new method leveraging machine-learning immunofluorescence image analysis. Metabolic markers were also investigated by RX Daytona automated clinical chemistry analyzer. Statistical analysis was conducted using a statistical package for the social sciences (SPSS) (α<0.05, significance). Preliminary results suggested the pumpkin pie spice mixture may improve inflammatory status. Compared to the control meal, the meal with pumpkin spice reduced nuclear translocation of NF-κB and proportion of PBMCs activation, p=0.007, and p=0.005, respectively. The addition of herbs/spices in HFHC meal had no apparent effect on postprandial glucose, insulin, or IL-6 concentrations compared to the control meal. Increased triglyceride concentrations were suggested after consuming the meal with Italian herbs compared to control (p=0.004). Overall, the results of this research suggested the potential of pumpkin pie spice as having anti-inflammatory effects in the context of a typical western-style eating pattern. A major component of this research was to develop a new method for assessing real-time inflammation in the human body. While the method and data are encouraging, upgrading image resolution and programming will be the subject of future research.
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Title: High-latitude plasma drift structuring from a first principles ionospheric model
Creator: Kim, Heejin
Date: 2020
Description: In the high-latitude ionosphere dense plasma formations called polar cap patches are sometimes observed. These patches are often associated...
Show moreIn the high-latitude ionosphere dense plasma formations called polar cap patches are sometimes observed. These patches are often associated with ionospheric scintillation, a rapid fluctuation in the amplitude and phase of a radio signal that degrades communications and navigation systems. Predicting polar cap patch movement across the polar cap is an important subject for enabling forecasting of the scintillation.Lagrangian coherent structures (LCSs) are ridges indicating regions of maximum fluid separation in a time-varying flow. In previous studies, the Ionosphere-Thermosphere Algorithm for Lagrangian Coherent Structures (ITALCS) predicted the location of LCSs. These LCSs were shown to constrain polar cap patch source and transport regions for flow assumed to due to $\vec{E} \times \vec{B}$ plasma drift. The LCSs were predicted based on an empirical model of the high-latitude electric field for $\vec{E}$. In this thesis, the LCSs are generated using the first principles ionospheric model SAMI3 (SAMI3 is Another Model of the Ionosphere) as the model for electric field. The work relies on an understanding of various magnetic coordinate systems in space science, and includes three different approaches for attempting to generate the $\vec{E} \times \vec{B}$ drift as the flow fields that are to input to ITALCS. Finally, a representative LCS result is obtained with SAMI3 and shown to be at the high latitudes on the dayside, similar to prior work, but spanning a shorter longitudinal range.
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Title: APPLICATIONS OF INTEGRATED DESIGN METHODOLOGIES: HYBRID AUTOMATION OF DESIGN SEQUENCING AND ITS INFLUENCE ON COMPLEX DESIGN PROJECTS
Creator: Elshanshoury, Waleed Farouk Omar
Date: 2020
Description: After the early development of Sketchpad in 1963 by Ivan Sutherland at MIT, the first system permitted drawing geometries parametrically;...
Show moreAfter the early development of Sketchpad in 1963 by Ivan Sutherland at MIT, the first system permitted drawing geometries parametrically; computation and algorithm aided design have significantly influenced the design practice. Computation and AAD are design approaches in which the medium of expression is logic instead of geometry. These approaches raised the curtain to various utilities, including but not limited to form-finding, automation, optimization, and robotic fabrication. Computational design and algorithm aided design are becoming fundamental approaches in most design practices because of their capability to solve complex problems.This thesis begins with a timeline presenting the evolution in design derivers and manifests how designers considered ideal design throughout history. This timeline starts with architecture approaches in ancient times when beauty, durability, and functions were the first principles to identify good architecture. It ends with the creation of computational technologies, which affected the design process and its logic. It will also investigate relations between software engineering and building design, where both fields intertwine with each other in general methodologies.This research examines how computation can generate integrated design systems to approach city planning and architectural design. IDS employs data, forces, and algorithms to construct a design system instead of solid geometries. This system combines the different design processes and chronological phases in interconnected blocks. This approach manages big data and assists in decision-making using automation, optimization, and machine learning technologies.This paper examines existing precedents, applications, and design projects that utilize IDS, including form-finding, materials, and energy. It will establish how evaluation criteria, simulations, solution optimizations, and processes automation play a vital role in integrated design systems. IDS is a dynamic workflow centered on principles and consists of components and aiding tools. This research explores technological aiding tools for these systems that help increase design performance and efficiencies using voice commands and automated functions.
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Title: Estimation of Platinum Oxide Degradation in Proton Exchange Membrane Fuel Cells
Creator: Ahmed, Niyaz Afnan
Date: 2024
Description: The performance and durability of Proton Exchange Membrane Fuel Cells (PEMFCs) can be significantly hampered due to the degradation of the...
Show moreThe performance and durability of Proton Exchange Membrane Fuel Cells (PEMFCs) can be significantly hampered due to the degradation of the platinum catalyst. The production of platinum oxide is a major cause of the degradation of the fuel cell system, negatively affecting its performance and durability. In order to predict and prevent this degradation, this research examines a novel method to estimate degradation due to platinum oxide formation and predict the level of platinum oxide coverage over time. Mechanisms of platinum oxide formation are outlined and two methods are compared for platinum oxide estimation. Linear regression and two Artificial Neural Network (ANN) models, including a Recurrent Neural Network (RNN) and Feed-forward Back Propagation Neural Network (FFBPNN), are compared for estimation. The estimation model takes into account the influence of cell temperature and relative humidity.Evaluation of relative errors (RE) and root mean square error (RMSE) illustrates the superior performance of RNN in contrast to GT-Suite and FFBPNN. However, both RNN and GT-Suite showcase an average error rate below 5% while the FFBPNN had a higher error rate of approximately 7%. The RMSE of RNN shows mostly less compared to FFBPNN and GT-Suite, however, at 50% training data, GT-Suite shows lowest RMSE. These findings indicate that GT-Suite can be a valuable tool for estimating platinum oxide in fuel cells with a relatively low RE, but the RNN model may be more suitable for real-time estimation of platinum oxide degradation in PEM fuel cells, due to its accurate predictions and shorter computational time. This comprehensive approach provides crucial insights for optimizing fuel cell efficiency and implementing effective maintenance strategies.
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Title: The Voderettes: Gender, Labor, and Techno-Utopia at the 1939 New York World's Fair
Creator: Simon, Sara M. B.
Date: 2024
Description: This thesis explores the labor demands of the Voder, the electrical speech synthesis machine developed by Bell Labs to be a major component of...
Show moreThis thesis explores the labor demands of the Voder, the electrical speech synthesis machine developed by Bell Labs to be a major component of AT&T's 1939 New York World's Fair exhibit. With the United States emerging from the Great Depression, and with political tensions escalating across the globe, the paper situates the Voder's labor demands within the historical context of the fair. Specifically, I explore the decision to have young women operate the Voder, the intricacies of the machine cloaked by the warm presence of its highly-skilled female operator. Using archival records from Bell Labs engineers, the paper exposes the previously unacknowledged engineering contributions of Voder operators in the years before the fair. These young women not only influenced major decisions about the Voder's mechanics but also gave early credence to the notion that developing a performance with the machine could make for a thrilling fair exhibit. Moreover, the paper argues that at the fair itself, AT&T and Bell Labs executives used the Voder operators to normalize a new vision of a technological utopia that relied heavily and conspicuously on the infrastructural labor of women. Given the Voder's legacy, as a tool that laid critical groundwork for voice encryption technology, the paper adds important context to the historical record, highlighting the young women at the heart of the machine.
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Title: Agency and Pathway Thinking as Mediators of The Relationship Between Caregiver Burden And Life Satisfaction Among Family Caregivers Of People With Parkinson’s Disease: An Application Of Snyder’s Hope Theory
Creator: Springer, Jessica Gabrielle
Date: 2024
Description: In the United States, there are 47.9 million caregivers providing care to family members with disabilities. Those providing care to someone...
Show moreIn the United States, there are 47.9 million caregivers providing care to family members with disabilities. Those providing care to someone who has Parkinson’s Disease (PD), a complex degenerative movement disorder, may have a unique caregiving experience, given that disease-related factors (e.g. motor and non-motor symptoms) can contribute to worsening caregiver burden and life satisfactions (LS). PD has an increasing incidence of 90,000 new cases per year, likely resulting in an increased need for caregivers. Caregiving research frequently focuses on the mediators between caregiver burden and LS including social support, coping skills, and appraisals. Research that has specifically focused on caregivers of people with PD (Pw/PD) is significantly limited. Hope is a “positive motivational characteristic comprised of agency and pathways thinking that can help facilitate drive towards one’s goal while also serving as a buffer against negative events” (Snyder et al.,1991). The goal of this study is to understand Snyder’s hope theory as it relates to caregiver burden and LS for caregivers of Pw/PD. Specifically, we hypothesized that (a) caregiver burden will be negatively correlated with agency thinking, pathways thinking, and LS among caregivers of Pw/PD. In addition, pathways thinking, and agency thinking will be positively associated with LS, and (b) agency thinking, and pathways thinking will mediate the relationship between caregiver burden and LS among caregivers of Pw/PD. The study sample consisted of 249 caregivers of Pw/PD who completed an online anonymous questionnaire. Correlations between agency and pathways thinking, LS, caregiver burden, and sociodemographic factors were evaluated. A parallel mediation analysis was run to evaluate the mediating roles of pathways and agency thinking in the relationship between caregiver burden and LS. Results indicated that LS was significantly and negatively correlated with caregiver burden. LS was significantly and positively correlated with both pathways and agency thinking. Pathways thinking had no indirect effect on the relationship of caregiver burden on LS. Agency thinking had a negative, indirect effect on the relationship suggesting that agency thinking partially mediated the relationship between caregiver burden and LS. Clinical implications and future directions are discussed.
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Title: Three-Dimensional Co-Culture Systems for Vascularization of Cardiac Tissue
Creator: Rodriguez Arias, Jessica A.
Date: 2023
Description: Myocardial Infarction (MI) is the partial or complete blockage of blood flow to the myocardial tissue resulting in damage and therefore loss...
Show moreMyocardial Infarction (MI) is the partial or complete blockage of blood flow to the myocardial tissue resulting in damage and therefore loss of heart function. In the U.S. every 40 seconds, someone will suffer from MI and the only available treatment is medication to treat the symptoms of heart function loss, but do not treat the underlying cause. Some attempts to treat the underlying cause have arisen in the last decades including cell-based therapies or tissue engineering therapies such as spheroid-based cardiac patches that have shown to be promising. Improvement in the mechanical properties to create suturable engineered tissues remain to be improved for ease of implantation purposes. Cell-laden hydrogel scaffolds can provide improved mechanical properties compared to biomaterial free cell-based therapies but need to allow for vascularization of the engineered tissue. Thus, the goal of this thesis is to provide preliminary studies for the use of a cell adhesive, proteolytically degradable PEG hydrogel scaffold that eventually would be used as an invitro model to evaluate engineered tissue vascularization for cardiac tissue engineering. To construct this model, important cell spheroid parameters on vascular invasion in 3D culture were investigated including the total number of cells/spheroid, the supporting cell for endothelial cells. In order to scale-up scaffolds to size of clinically relevant dimensions, a multilayered hydrogel construct visible light free-radical polymerization approach encapsulating vascular spheroids in multiple layers was also investigated. Results indicate that a total cell number of 5000 cells/spheroid aggregate were feasible due to cell sourcing. In addition, co-cultures of endothelial and mesenchymal stem cells led to maximized vascular invasion of the spheroids compared to fibroblast/endothelial co-culture and endothelial monoculture of spheroids in the hydrogel. Finally, the extent of vascularization of spheroids in each layer of the multilayered hydrogel constructs varied due to the observed differences in mechanical properties and swelling ratio of each layer due to incomplete polymerization of layers. This study demonstrated the importance of support cells and hydrogel mechanical properties in promoting vascularization of spheroid which serves as basis for building cell-laden hydrogel scaffolds for vascularization for cardiac tissues.
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Title: Population Dynamics of Listeria monocytogenes in Nut, Seed and Legume Butters
Creator: Zhang, Xinyuan
Date: 2020
Description: Nut, seed, and legume butters are low water activity foods and do not support the growth of foodborne pathogens. Research has determined that...
Show moreNut, seed, and legume butters are low water activity foods and do not support the growth of foodborne pathogens. Research has determined that some pathogens, such as Listeria monocytogenes, can survive for long periods of time in butters, such as almond butter. However, information on the persistence of L. monocytogenes in butters is lacking. The purpose of this study was to determine the population dynamics of L. monocytogenes in butters stored at 5 and 25°C. Nut (almond, hazelnut, pecan), seed (pumpkin, sesame, sunflower), legume (peanut and soy) and butters containing chocolate (hazelnut and peanut) were inoculated with a 4-strain cocktail of rifampicin-resistant L. monocytogenes at 4 (high inoculation) or 1 log CFU/g (low inoculation). High inoculation butters were mixed by hand for 15 min and 100-g portions were weighed into deli-style containers with lids and stored at 5 or 25°C for 12 mo (370 d). Low inoculation butters were stored in 25- g portions in stomacher bags at 25°C for 6 mo (180 d). During storage, 25 g from the 100- g high inoculation portion or 25 g from the low inoculation samples, in triplicate, were homogenized with 225 mL BPB (or BLEB for FDA BAM enrichments when necessary) and serial dilutions of the homogenate were plated onto BHIA with rifampicin for enumeration of L. monocytogenes. Data were statistically analyzed using Student’s t-test (α=0.05). The average initial population of L. monocytogenes in the butters was 3.58±0.25 log CFU/g for the high inoculation butters; L. monocytogenes was detected through enrichments for all low inoculation butters. After 12 mo storage at 5°C, the population of L. monocytogenes decreased by 1.34, 1.27, 1.72, 2.04 and 0.93 log CFU/g in almond, hazelnut, peanut with chocolate, hazelnut with chocolate and pecan butter, respectively, when inoculated at the higher level. Significantly less population reduction was observed in pumpkin, sesame, soy, peanut and sunflower butters (1.08, 0.61, 0.84, 0.05 and 0.40 log CFU/g, respectively). After 12 mo storage at 25°C, the L. monocytogenes population in all butters, with the exception of sunflower butter, decreased to below the limit of enumeration (1.67 log CFU/g), but the pathogen was still present via enrichment. For low inoculation butters, L. monocytogenes was present as determined by enrichment in all butters in at least one of two trials after 6 mo. The results of this study provide information on the survival of L. monocytogenes in different butter types when stored at different temperatures.
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Title: Intraoperative Assessment of Surgical Margins in Head And Neck Cancer Resection Using Time-Domain Fluorescence Imaging
Creator: Cleary, Brandon M.
Date: 2023
Description: Rapid and accurate determination of surgical margin depth in fluorescence guided surgery has been a difficult issue to overcome, leading to...
Show moreRapid and accurate determination of surgical margin depth in fluorescence guided surgery has been a difficult issue to overcome, leading to over- or under-resection of cancerous tissues and follow-up treatments such as ‘call-back’ surgery and chemotherapy. Current techniques utilizing direct measurement of tumor margins in frozen section pathology are slow, which can prevent surgeons from acting on information before a patient is sent home. Other fluorescence techniques require the measurement of margins via captured images that are overlayed with fluorescent data. This method is flawed, as measuring depth from captured images loses spatial information. Intensity-based fluorescence techniques utilizing tumor-to-background ratios do not decouple the effects of concentration from the depth information acquired. Thus, it is necessary to perform an objective measurement to determine depths of surgical margins. This thesis focuses on the theory, device design, simulation development, and overall viability of time-domain fluorescence imaging as an alternative method of determining surgical margin depths. Characteristic regressions were generated using a thresholding method on acquired time-domain fluorescence signals, which were used to convert time-domain data to a depth value. These were applied to an image space to generate a depth map of a modelled tissue sample. All modeling was performed on homogeneous media using Monte Carlo simulations, providing high accuracy at the cost of increased computational time. In practice, the imaging process should be completed within a span of under 20 minutes for a full tissue sample, rather than 20 minutes for a single slice of the sample. This thesis also explores the effects of different thresholding levels on the accuracy of depth determination, as well as the precautions to be taken regarding hardware limitations and signal noise.
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Title: Improving Niobium Superconducting Radio-Frequency Cavities by Studying Tantalum
Creator: Helfrich, Halle
Date: 2023
Description: Niobium superconducting radio-frequency (SRF) cavities are widely used accelerating structures. Improvements in both quality factor, Q0, and...
Show moreNiobium superconducting radio-frequency (SRF) cavities are widely used accelerating structures. Improvements in both quality factor, Q0, and maximum accelerating gradient, Eacc, have been made to SRF cavities by introducing new processing techniques. These breakthroughs include processes such as nitrogen doping(N-Doping) and infusion, electrochemical polishing (EP) and High Pressure Rinsing (HPR). [1] There is still abundant opportunity to improve the cavities or, rather, the material they’re primarily composed of: niobium. A focus here is the role the native oxide of Nb plays in SRF cavity performance. The values of interest in a given cavity are its quality factor Q0, maximum accelerating gradient Eacc and surface resistance Rs . This work characterizes Nb and Ta foils prepared under identical conditions using X-ray photoelectron spectroscopy (XPS) to compare surface oxides and better understand RF loss mechanisms in Nb SRF cavities and qubits. It is well established that Ta qubits experience much longer coherence times than Nb qubits, which is probably due to the larger RF losses in Nb oxide. By studying Tantalum, an element similar to Niobium, the mechanisms of the losses that originate in the oxide and suboxide layers present on the surface of Nb cavities might finally be unlocked. We find noticeable differences in the oxides of Nb and Ta formed by air exposure of clean foils. In particular, Ta does not display the TaO2 suboxide in XPS, while Nb commonly shows NbO2. This suggests that suboxides are an additional contributor of RF losses. We also suggest that thin Ta film coatings of Nb SRF cavities may be a way of increasing Q0. It is in the interest of the accelerator community to fully understand the surface impurities present in Nb SRF cavities so that strategies for mitigating the effects can be proposed.
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Title: Independence and Graphical Models for Fitting Real Data
Creator: Cho, Jason Y.
Date: 2023
Description: Given some real life dataset where the attributes of the dataset take on categorical values, with corresponding r(1) × r(2) × … × r(m)...
Show moreGiven some real life dataset where the attributes of the dataset take on categorical values, with corresponding r(1) × r(2) × … × r(m) contingency table with nonzero rows or nonzero columns, we will be testing the goodness-of-fit of various independence models to the dataset using a variation of Metropolis-Hastings that uses Markov bases as a tool to get a Monte Carlo estimate of the p-value. This variation of Metropolis-Hastings can be found in Algorithm 3.1.1. Next we will consider the problem: ``out of all possible undirected graphical models each associated to some graph with m vertices that we test to fit on our dataset, which one best fits the dataset?" Here, the m attributes are labeled as vertices for the graph. We would have to conduct 2^(mC2) goodness-of-fit tests since there are 2^(mC2) possible undirected graphs on m vertices. Instead, we consider a backwards selection method likelihood-ratio test algorithm. We first start with the complete graph G = K(m), and call the corresponding undirected graphical model ℳ(G) as the parent model. Then for each edge e in E(G), we repeatedly apply the likelihood-ratio test to test the relative fit of the model ℳ(G-e), the child model, vs. ℳ(G), the parent model, where ℳ(G-e) ⊆ℳ(G). More details on this iterative process can be found in Algorithm 4.1.3. For our dataset, we will be using the alcohol dataset found in https://www.kaggle.com/datasets/sooyoungher/smoking-drinking-dataset, where the four attributes of the dataset we will use are ``Gender" (male, female), ``Age", ``Total cholesterol (mg/dL)", and ``Drinks alcohol or not?". After testing the goodness-of-fit of three independence models corresponding to the independence statements ``Gender vs Drink or not?", ``Age vs Drink or not?", and "Total cholesterol vs Drink or not?", we found that the data came from a distribution from the two independence models corresponding to``Age vs Drink or not?" and "Total cholesterol vs Drink or not?" And after applying the backwards selection likelihood-ratio method on the alcohol dataset, we found that the data came from a distribution from the undirected graphical model associated to the complete graph minus the edge {``Total cholesterol”, ``Drink or not?”}.
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Title: Development of a Model To Investigate Inflammation Using Peripheral Blood Mononucleated Cells
Creator: Geevarghese Alex, Peter
Date: 2023
Description: Our modern culture in our society is facing one of the biggest risks in health which is high-calorie diet-related postprandial inflammation....
Show moreOur modern culture in our society is facing one of the biggest risks in health which is high-calorie diet-related postprandial inflammation. Chronic diseases may be caused if the energy-dense food is the choice meaning if it is uncontrolled, clinical studies have demonstrated this with the body's post-meal inflammatory response. We aimed to find the causes of postprandial inflammation in response to various dietary treatments and provide a model to demonstrate. We aimed to make use of in vivo and in vitro techniques and statistics to create a model. The created model would help us to design specific treatments to minimize inflammation with response to dietary. In addition to figuring out vital dietary additives, the model additionally facilitates the layout of individualized interventions to reduce inflammation, thereby improving long-time period health outcomes. We aim to understand the clinical observations of diet-induced postprandial inflammation on the molecular level. We desire to make contributions to reduce the impact of chronic inflammatory disorders that is associated with postprandial inflammation.
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Title: Large Language Model Based Machine Learning Techniques for Fake News Detection
Creator: Chen, Pin-Chien
Date: 2024
Description: With advanced technology, it’s widely recognized that everyone owns one or more personal devices. Consequently, people are evolving into...
Show moreWith advanced technology, it’s widely recognized that everyone owns one or more personal devices. Consequently, people are evolving into content creators on social media or the streaming platforms sharing their personal ideas regardless of their education or expertise level. Distinguishing fake news is becoming increasingly crucial. However, the recent research only presents comparisons of detecting fake news between one or more models across different datasets. In this work, we applied Natural Language Processing (NLP) techniques with Naïve Bayes and DistilBERT machine learning method combing and augmenting four datasets. The results show that the balanced accuracy is higher than the average in the recent studies. This suggests that our approach holds for improving fake news detection in the era of widespread content creation.
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Title: Migration of Silver from Silver Zeolite/Low-Density Polyethylene Films into Food Stimulants
Creator: Sayeed, Maryam
Date: 2023
Description: Zeolites are naturally occurring or synthetic crystalline microporous aluminosilicate structures with remarkable catalytic, adsorption, and...
Show moreZeolites are naturally occurring or synthetic crystalline microporous aluminosilicate structures with remarkable catalytic, adsorption, and ion-exchange properties. Their unique framework of pores, channels, and cages with precise dimensions makes them an excellent fit for ion exchange and storage. Silver-exchanged zeolite (Ag/Y) composites may be incorporated into polymer matrices to create antimicrobial packaging materials. The slow release of Ag from nanosilver-enabled polymer nanocomposites (PNCs) may inhibit the growth of bacteria and other pathogens on the film’s surface, improving food quality and reducing food waste. However, the migration of Ag ions from the film into food matrices is of great concern as it could expose humans to high concentrations of a heavy metal from dietary sources. The amount of migration depends on various factors, including the potential form of Ag and its concentration in the film, the film thickness, and the storage conditions.The primary objective of this study is to investigate the effect of the form of Ag bound to the zeolite on the migration behavior of Ag from Ag/Y incorporated low-density polyethylene (LDPE) films. For Ag/Y-incorporated LDPE PNCs with distinct Ag species, the Ag migration into the water and Squirt (a commercial soft drink) was at least four times higher from films containing zeolites exchanged with ionic Ag versus zeolites exchanged with nanoparticulate Ag. Similarly, migration into 9 wt % aqueous Domino sugar (granulated sucrose) solution was seven times higher in the ionic silver-incorporated film than in the nanoparticulate Ag film. This study suggests that it is important to consider the form of Ag in silver-exchanged zeolite while producing packaging materials since the potential form of Ag in the PNCs might significantly affect Ag migration behavior.
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Title: Improving self-supervised monocular depth estimation from videos using forward and backward consistency
Creator: Shen, Hui
Date: 2020
Description: Recently, there has been a rapid development in monocular depth estimation based on self-supervised learning. However, these existing self...
Show moreRecently, there has been a rapid development in monocular depth estimation based on self-supervised learning. However, these existing self-supervised learning methods are insufficient for estimating motion objects, occlusions, and large static areas. Uncertainty or vanishing easily occurs during depth inferencing. To address this problem, the model proposed in this thesis further explores the consistency in video and builds a multi-frame model for depth estimation; secondly, by taking advantage of the optical flow, a motion mask is generated, with additional photometric loss applied for those masked regions. Experiments are carried out on the KITTI dataset. The proposed model performs better than the baseline model in quantitative results, and as seen from the depth map, the scale uncertainty and depth incomplete situations are improved in motion objects and occlusions explicitly.
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Title: Factor Analysis of the Neurobehavioral Symptom Inventory in Veterans with Posttraumatic Stress Disorder
Creator: Scimeca, Lauren
Date: 2020
Description: The Neurobehavioral Symptom Inventory (NSI) is a widely used measure of postconcussive symptoms in veteran populations. Previous psychometric...
Show moreThe Neurobehavioral Symptom Inventory (NSI) is a widely used measure of postconcussive symptoms in veteran populations. Previous psychometric studies used samples of veterans with mild Traumatic Brain Injury (mTBI) and high rates of comorbid Posttraumatic Stress Disorder (PTSD). The present study aims to determine the best-fitting factor structure of the NSI in veterans with PTSD and to evaluate the relationship between the best-fitting factor structure and the symptom clusters of PTSD. A confirmatory factor analysis (CFA) found that 4-factors had the best overall fit in veterans with PTSD. Correlational analyses found high rates of correspondence between the cognitive and affective factors of the NSI and the alterations in cognition and mood and hyperarousal symptom clusters of PTSD. The analyses reveal that symptoms of the NSI cluster in the same way in a sample of veterans with PTSD as they do in veterans with mTBI, suggesting that lingering postconcussive symptoms in veterans with PTSD are better characterized as non-specific generalized health symptoms on the NSI.
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Title: CONCEPTUAL COST ESTIMATION MODEL FOR BRIDGES WITH RESPECT TO ABC METHODS
Creator: Rajeei, Farshad
Date: 2020
Description: As the need for renovating and repairing structurally deficient and functionally obsolete bridges is increased, employing innovative methods...
Show moreAs the need for renovating and repairing structurally deficient and functionally obsolete bridges is increased, employing innovative methods which can lead to shorter construction time, better quality, longer durability, and less life-cycle costs become more popular in transportation agencies.Developing a model that has the capability of estimating the total construction cost of ABC projects and compare them with conventional methods costs [without using these methods] will help decision-makers at DOTs in understanding and assessing the benefits and costs of ABC methods at the planning phase of a project and in return, will lead to the elaboration in the use of ABC methods versus the conventional ones. But this decision making process is complicated since the number of executed ABC projects, especially those which done by SIBC and SPMT [two superstructure replacement method] is limited and as a result; there is a lack of historical knowledge to estimate the associated cost of these methods in future projects. Factors affecting this process include but are not limited to: construction costs, user costs, quality of work, impact on traffic, the safety of road users and construction workers, and the impact on surrounding communities and businesses. The main aim of this study is to make a model to estimate additional costs of using SIBC and SPMT methods and the saving in user costs.
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Title: PTSD Symptoms as a Potential Link Between Military Sexual Assault and Disordered Eating
Creator: Sandhu, Danielle
Date: 2020
Description: Despite increasing rates of sexual assault in the military and high rates of disordered eating and posttraumatic stress disorder (PTSD) among...
Show moreDespite increasing rates of sexual assault in the military and high rates of disordered eating and posttraumatic stress disorder (PTSD) among veterans, little is known about how these constructs are related. The present study examined whether PTSD symptoms mediate the relation between military sexual assault and disordered eating among female veterans. Prolific Academic was used to recruit 98 United States female veterans as participants for the study. Participants completed an online questionnaire of self-report measures assessing demographic characteristics, military sexual assault, PTSD symptoms, and disordered eating. Mediational analyses were conducted using the PROCESS v3 macro in IBM SPSS Statistics. Within the sample, 61% of female veterans reported being sexually assaulted while serving in the military. Military sexual assault was associated with higher levels of PTSD symptoms and disordered eating. Findings did not support the hypothesis that PTSD symptoms would mediate the relation between military sexual assault and disordered eating among women veterans. Given the heterogeneous nature of disordered eating, post-hoc mediational analyses were conducted to examine specific facets of eating pathology. Results indicated that PTSD symptoms fully mediated the relation between military sexual assault and bulimia and food preoccupation. Awareness of these psychopathological sequelae following military sexual assault may improve screening and intervention efforts at Veteran Affairs (VA) medical centers. The present study highlights the importance of future longitudinal studies that can establish temporal precedence in order to better understand the pathways leading to disordered eating in female veterans.
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