Search results

Title: Modeling the Glycemic Response to Physical Activity and Athletic Competition Anxiety in People with Type 1 Diabetes
Creator: Hobbs, Nicole B.
Date: 2021
Description: The first observational study of recreational athletes with T1D during a meaningful athletic competition and a non-competitive exercise...
Show moreThe first observational study of recreational athletes with T1D during a meaningful athletic competition and a non-competitive exercise session was conducted. Non-invasive wearable devices and surveys are used to identify the presence or absence of competition stress during physical activity and to estimate physical activity intensity. An elevated glycemic trend on the day of an athletic competition is a frequent complaint among people with T1D and this increase was consistently observed in our study population. The elevation in glycemia is impacted by the individual behavior related to diabetes management and this behavioral change is impacted by the individual’s duration of diabetes and other demographic traits. A physical activity-intensity dependent model of glucose-insulin dynamics was developed for a type 1 diabetes simulator as a basis for the development of multivariable artificial pancreas systems. Several potential model structures were compared to assess the influence of model terms related to endogenous glucose production, glucose utilization, and glucose transfer. The model including all three terms accurately describes the relation of plasma insulin and physical activity intensity upon glucose production and glucose utilization to generate the appropriate glucose response for each physical activity condition ranging from low to maximal intensity efforts. All artificial pancreas performance metrics have been determined based upon physician-defined metrics for success. An online survey was conducted to assess individual goals for diabetes management, and for many individuals, the ability to achieve personalized metrics is unnecessary as their goals match the general metrics. As individual targets may be set by the individual or their doctor, the ability to achieve those are still of interest. A framework to target the individual management goals with the multivariable artificial pancreas system is developed which increased the percentage of time spent in each individual target range in simulations.
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Title: FIELD EMISSION MITIGATION VIA IN-SITU PLASMA PROCESSING IN 1.3 GIGAHERTZ 9-CELL LCLS-II CAVITIES
Creator: Giaccone, Bianca
Date: 2021
Description: Field emission (FE) is one of the limiting factors in superconducting radiofrequency cavities' performance. It is known that even a few...
Show moreField emission (FE) is one of the limiting factors in superconducting radiofrequency cavities' performance. It is known that even a few monolayers of surface adsorbed contaminants can lower the niobium work function and increase the FE. In order to address the field emission that may arise once the accelerator is already assembled, it was decided to develop plasma processing for the Linac Coherent Light Source II, a method to mitigate field emission in-situ. Starting from Doleans's successful experience with plasma processing for high beta cavities, Fermi National Accelerator Laboratory is developing plasma cleaning for TESLA shaped 1.3 GHz 9-cell cavities. A new method of ignition based on the higher order modes and couplers was developed, along with a detection procedure that allows to identify the location of the plasma inside the cavity. In this work are presented the results of plasma processing applied to 1.3 GHz cavities, both single-cell and 9-cells. The cavities were contaminated with multiple sources, naturally or artificially, and their performance was measured through cryogenic RF tests before and after plasma cleaning. These experiments proved that plasma processing successfully removed hydrocarbon-related field emission from cavities artificially contaminated, but also from a cavity with natural and unknown FE source. In some cases of more extreme contamination through vacuum failure simulation conducted in air (not in a cleanroom), plasma processing was not able to recover the cavity's performance. An ongoing analysis of the cavity contaminants is presented here, explaining the reason why some contaminated cavities showed little improvement after plasma processing. A microscopic study of the effect of plasma processing on the niobium surface is also presented. Niobium samples prepared with different surface treatments were analyzed using X-ray photoelectron spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The samples were subjected to plasma processing and analyzed again, in order to draw a comparison and identify possible surface changes caused by the reactive oxygen contained in the glow discharge. The samples were prepared with different surface treatments in order to understand if plasma processing may affect them differently. This study showed a possible increase in the oxide thickness after plasma processing and a reduction of the energy difference between the pentoxide and the metal peaks. In preparation for this study, the near-surface region of one niobium sample was investigated with X-ray photoelectron spectroscopy at various steps of sputtering and subsequent oxide regrowth in air. The results showed that the majority of the oxide is composed of Nb2O5, however, the presence of two suboxides (NbO, NbO2) is observed, plus an additional peak (attributed to Nb2O) measured both during sputtering and oxide regrowth.
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Title: Attitudes of Adults Treated for Depression Toward Technology-Assisted Therapy
Creator: Johnston, Winter D.
Date: 2021
Description: Depression is associated with functional impairment (Saarni et al., 2007), high economic costs (Cuijpers et al., 2007; Greenberg & Birnbaum,...
Show moreDepression is associated with functional impairment (Saarni et al., 2007), high economic costs (Cuijpers et al., 2007; Greenberg & Birnbaum, 2005), and loss of quality of life (Rapaport et al., 2005), and has been named a major reason for illness-related disability worldwide (Vos et al., 2013). Barriers to treatment include being physically limited to access services (Apolinario-Hagen et al., 2018), fear of stigmatization, desire to handle the problem on ones’ own, lack of confidence in the healthcare system (Königbauer et al., 2017), lack of motivation to change, and negative perception of psychological and/or drug treatments (Richards et al., 2015). As technological options have advanced and become more reliable, they have become tools to improve access to care and reduce barriers. Clinicians’ attitudes have been studied pertaining to incorporating different technology modalities into traditional therapy; however, client attitudes are less explored. The present study aims to (1) explore client attitudes towards hypothetical technology-assisted interventions, (2) assess the relative preferences for various technology-assisted interventions, (3) identify correlates of the participant’s preference of different technology-assisted interventions, including: (a) attitudes towards technology-assisted therapy, (b) sociodemographic variables, (c) help-seeking variables (seeking health information, use of technology outside therapy, awareness of technology-assisted options for therapy), (d) previous therapy experience (therapeutic approach, helpfulness of therapy, number of previous therapists), and (4) assess if working alliance with participants’ most recent therapist moderated the effect of therapist condition (current/recent or new) on preferences. The technology options in this study are videoconferencing, online therapy, mobile phones, and virtual reality/avatars. Individuals were asked to imagine continuing therapy using these technological options. Participants viewed videos demonstrating how each technology is used in a therapeutic setting and provided their attitudes and preferences afterwards. The participants consisted of adults who currently or in the recent past have received therapy to treat any severity of depression. Overall, participants had a positive attitude towards technology-assisted therapy. Participants’ relative preference for various technology-assisted interventions and their first-choice modality of therapy did not differ by whether the participant was to keep their same therapist or start therapy with a new therapist. A variety of determinants were associated with greater preference towards the different modalities. Lastly, the strength of working alliance did not moderate whether preferences differed based on staying with the participant’s current/most recent therapist or starting with a new therapist. Limitations, strengths, and conclusions are also discussed.
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Title: UNDERSTANDING MARIJUANA USE AS A TREATMENT OPTION FOR PEOPLE WITH EPILEPSY: USE, ATTITUDES, AND QUALITY OF LIFE
Creator: Johnson, Kristina
Date: 2021
Description: Epilepsy is the most common neurological disorder worldwide with a heterogeneous range of negative symptoms. Current treatments for epilepsy...
Show moreEpilepsy is the most common neurological disorder worldwide with a heterogeneous range of negative symptoms. Current treatments for epilepsy have side effects that can negatively impact the quality of a person’s life. Alternative treatments are being explored, including marijuana. This study aimed to understand marijuana use in adults with epilepsy across U.S. states. Rates of use, preferred method of use, and reasons to use and not use marijuana were examined. Additionally, levels of comfort discussing marijuana compared to other treatment options and with different types of providers were explored. Lastly, this was one of the first studies to examine the relationship between quality of life (QOL) and marijuana use for people with epilepsy. Participants included 128 individuals with epilepsy from 26 states, with non-legal states having significantly fewer people who reported using marijuana. Smoking was reported as the primary method of use, knowing someone else that uses as their primary reason for using, and health concerns as the primary reason not to use. There was no difference in level of comfort discussing marijuana compared to other treatments, and participants reported feeling most comfortable discussing marijuana with neurologists compared to other providers. Finally, total QOLIE-31 and the social functioning subscale were significantly lower among marijuana users; however, this difference did not remain when anxiety was entered as a covariate. In fact, the relationship between anxiety and QOL was significant, with anxiety accounting for η2 = .12 to η2 = .57 of the variance in QOLIE-31 subscale scores, controlling for marijuana use. Findings from this study further the understanding of marijuana use by people with epilepsy in the United States.
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Title: FACTORS INFLUENCING INDIVIDUALS’ PROVISION OF AUTONOMY SUPPORT TO THEIR PARTNERS WITH CHRONIC PAIN: A PATH ANALYSIS MODEL BASED ON SELF-DETERMINATION THEORY
Creator: Ivins-Lukse, Melissa N.
Date: 2021
Description: Receiving autonomy support from a relationship partner has been associated with increased physical activity among individuals with chronic...
Show moreReceiving autonomy support from a relationship partner has been associated with increased physical activity among individuals with chronic pain (ICP), but no studies have explored what factors may influence partners’ use of an autonomy supportive interpersonal style with an ICP. Self-determination theory (SDT) posits that contextual, perceptual, and individual factors influence how much individuals use an autonomy supportive interpersonal style through the mediators of basic psychological need satisfaction and autonomous motivation. The present study used path analysis to test a SDT model of the relationships between a contextual factor (autonomy support from health care provider), a perceptual factor (partner’s perception of ICP motivation for physical activity), an individual factor (partner catastrophizing about ICP’s pain), and the sequential mediators of relationship need satisfaction and autonomous motivation with respect to the dependent variable of partners’ use of an autonomy supportive interpersonal style. 176 partners of ICPs completed a cross-sectional survey including the Health Care Climate Questionnaire, partner-report revised Behavioral Regulation in Exercise Questionnaire, Pain Catastrophizing Scale – Significant Other version, Need Satisfaction Scale, Motivation to Help, and Interpersonal Behaviours Questionnaire-Self. The proposed model demonstrated poor fit to the data: χ2 (10) = 31.949, p < 0.001), RMSEA = 0.11 (90% CI = .07 to .16, p = 0.01), CFI = 0.81, and SRMR = .10. While the overall model was not supported, most individual pathways in the model were significant. Alternative analyses were conducted to identify a model with acceptable fit.
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Title: THE RELATIONSHIP BETWEEN SLUGGISH COGNITIVE TEMPO AND PERFORMANCE ON TASKS OF PROCESSING SPEED: INFLUENCE OF DEPRESSION
Creator: Kim, Jeong Hye
Date: 2021
Description: Sluggish cognitive tempo (SCT) is often associated with reported difficulties in various functional areas, including daily activities,...
Show moreSluggish cognitive tempo (SCT) is often associated with reported difficulties in various functional areas, including daily activities, emotional functioning, cognitive functioning, academic performance, and sleep. However, there are only a handful of research studies on SCT and neurocognitive functioning in adult populations, and the neuropsychological profile of SCT in adults is unclear.The purpose of this research is to investigate the effect of depression on the relationship between a self-reported measure of SCT and objective measures of SCT in adults by focusing on processing speed performance. The result of this research supports the previous notion that SCT is a novel and independent condition distinct from ADHD, and there are significantly positive relationships between symptoms of SCT and Inattention and Hyperactivity/Impulsivity. Furthermore, SCT and depression are also positively associated indicating the people who experience more symptoms of SCT report more symptoms of depression. However, results did not support the hypothesis that SCT significantly contribute to differences in performance on various types of neuropsychological tasks (WAIS PSI, Trail Making Test, and CPT-II Reaction Time) assessing processing speed after controlling for symptoms of ADHD (inattention and hyperactivity/impulsivity) and symptoms of depression. It is notable that the significant model beta weights for SCT in the final regression model suggests that the relationship between SCT and processing speed is worthy of additional investigation.
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Title: Language, Perception, and Causal Inference in Online Communication
Creator: Wang, Zhao
Date: 2021
Description: With the proliferation of social media platforms, online communication is becoming increasingly popular. The nature of a wide audience and...
Show moreWith the proliferation of social media platforms, online communication is becoming increasingly popular. The nature of a wide audience and rapid spread of information make these platforms attractive to public entities, organizations, and individuals. Marketers use these platforms to advertise their products and collect customer feedbacks (e.g. Amazon, Airbnb, Yelp, IMDB). Politicians use these platforms to directly speak with the public and canvass for votes (e.g., Twitter, Youtube, Snapchat). Individuals use these platforms to connect with friends and share daily life (e.g., Twitter, Facebook, Instagram, Weibo). The various platforms allow users to build public image and increase reputation through a fast and cheap way. However, due to the lack of regulations and low effort of online communication, some users try to manage their public impression using vague and tricky expressions during communication, making it hard for the audience to identify the authenticity of the public messages. Studies across many disciplines have shown that words and language play an important role in effective communication but the nature and extent of this role remain murky. Prior works have investigated wording effect on audience perception, but we still need automatic methods to estimate the causal effect of lexical choice on human perception in large scale. Getting insights into the treatment effect of subtle linguistic signals is crucial for intelligent language understanding and text analysis.The causal estimation of wording effect on perception also provides us an alternative way to understand the causal relationship between word features and perception labels. Comparing with correlational associations between features and labels, which is typically learned by statistical machine learning models, we find inconsistencies between the causal and correlational associations. These inconsistencies suggest possible spurious correlations in text classification and it's significant to address this issue by applying causal inference knowledge to guide statistical classifiers.In this thesis, our first goal is to investigate wording effect in online communication and study causal inference in text. We start from a deceptive marketing task to quantify entities' word commitment from online public messaging and identify potentially inauthentic entities. We then propose several frameworks to estimate the causal effects of word choice on audience perception by adapting Individual Treatment Effect estimation from causal inference literature to our problem of Lexical Substitution Effect estimation. The findings from these projects motivate us to explore our second goal of applying causal inference knowledge to improve statistical model robustness. Specifically, we study the causal and correlational associations in text and discover possible spurious correlations in text classifiers. Then, by extending the causal discovery, we propose two frameworks to improve text classifier robustness and fairness either by directly removing bias correlations or by training a robust model with automatically generated counterfactual samples.
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Title: REVISITING MODERNIST MASS-HOUSING: RESIDENTS AS ACTIVE AGENTS OF CHANGE
Creator: Shah, Nadia
Date: 2021
Description: In this PhD research, I have examined the modernist approach of mid-20thcentury mass housing projects against the backdrop of post-colonial...
Show moreIn this PhD research, I have examined the modernist approach of mid-20thcentury mass housing projects against the backdrop of post-colonial nation building and the need for housing refugees through resettlement projects after World War II. In this epoch most of the refugees were accommodated in newly decolonized nation states that were struggling to create their national identity as ‘modern'. It was at this critical moment in history, when the West assumed the paternalistic role of development of the so-called ‘Third World’, the ‘Global South’ or the ‘Underdeveloped Nations’, that they defined what is 'modern' using Western standards of ‘normalcy’. Aboard this international development project, architectural modernism’s response was to ‘generalize problems’ and provide ‘normative prescriptions’ as solutions based on rational models. I have reviewed the timeline of modernist ideas that led to mass housing and the associated notion of ‘normalization of space,’ presenting three scales used to organize society: regional planning, land use zoning, and mass-produced architecture, as a prescriptive process. I have examined architecture’s ‘normalization’ as a source of conflict for nation states in their process of national identity formation. I argue that the pedagogy of both modernism and late modernism, presented cultural distinction as an intermediary condition that was subject to change. In particular, modernist architecture engaged with the “concept of normalcy” for the formation of a modern society through spatial and physical organization. Using the case study of Pakistan, I present how this notion was at odds with Pakistani nationalism, since the country was created on the premise to house a traditional society. I have used the example of the Greek architect, Constantinos Doxiadis and his trajectory of late modernism for solving the global housing crisis after World War II. For this purpose, I present the case of a particular post World War II refugee resettlement project called Korangi Town in Karachi Pakistan. This case is studied in the light of modernist planning and architectural models to examine what was proposed, designed, and predicted by this professional architect and how Korangi Town has evolved in the past sixty years. The objective is to see how the new normal architecture and planning standards of the West were received in the non-Western culture? The case study of Korangi Town reveals that the residents of a locale may organize themselves along cultural and ethnic lines, deviating from implemented prescriptive and normative solutions. The changes that the residents made to their built environment through the processes identified as ‘appropriation’, ‘adaptation’ and ‘expansion’ in the dissertation are interpreted as the signs of their active agency. The residents’ agency emerges to reshape their built environs to meet their cultural and individual needs, but most of all their economic needs. These observations show that rather than being passive recipients of ready-made and prescriptive solutions, the residents were active agents in adjusting and adding to their environment. Inhabitants’ active agency needs attention by the planning and architecture professions to assure that environments intended for them have their meaningful input. This dissertation raises questions about how these professions can support this active agency from the beginning and through the planning and design processes.
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Title: On the Study of Successful Derivatives: A Holistic Approach to the Standardization of Financial Innovation
Creator: Schoinas, Konstantinos Georgios
Date: 2021
Description: This dissertation attempts a contribution toward a much-needed holistic understanding surrounding the trading dynamics of exchange-based...
Show moreThis dissertation attempts a contribution toward a much-needed holistic understanding surrounding the trading dynamics of exchange-based derivative products. The latter proxying such products’ commercial performance. Hence, upon identifying the lack of a measurement standard as the underlying reason for the attested and motivating knowledge deficit, we adopt a two-step approach for the development thereof: At first an integrated conceptual framework is established and, subsequently, a normalization standard is derived. In result, across-product trading dynamics are rendered directly comparable; arguably, for the first time ever. Furthermore, we also explore the existing postulation of balanced liquidity commitments between the groups of hedgers and speculators and posit the construct of a corresponding temporarily stable equilibrium. The latter serves as the first dimension on which the developed measurement standard may be applied. Accordingly, we conduct empirical research predicated on an extensive dataset with daily trading activity and, just as theorized, reject the hypothesis that the aforementioned speculator-hedger ratio is non-stationary. We then proceed in studying the trading dynamics of individual derivatives, implementing the developed standard by means of longitudinal analyses for second time. To a large extent our results do not contradict the body of related literature, which however has been essentially based on heuristic approaches to this time. Nevertheless, in its course, this study also highlights the need to shift the entire paradigm of studying individual derivatives trading success – from a single-faceted – to two separate effects: one anchored to the short term ‘steam gathering’ capacity of newly launched products and another associated with the notion of established products’ longevity. Altogether then, this study aspires to serve as a solid first step in systematically answering Webb’s (2018) call to confront the still unknown causes of derivatives’ success, or lack thereof.
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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: 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: Reconfigurable High-Performance Computation and Communication Platform for Ultrasonic Applications
Creator: Wang, Boyang
Date: 2021
Description: In industrial and medical applications, ultrasonic signals are used in nondestructive testing (NDT), medical imaging, navigation, and...
Show moreIn industrial and medical applications, ultrasonic signals are used in nondestructive testing (NDT), medical imaging, navigation, and communication. This study presents the architecture of high-performance computational systems designed for ultrasonic nondestructive testing, data compression using machine learning, and a multilayer perceptron neural network for ultrasonic flaw detection and grain size characterization. We researched and developed a real-time software-defined ultrasonic communication system for transmitting information through highly reverberant and dispersive solid channels. Orthogonal frequency-division multiplexing is explored to combat the severe multipath effect in the solid channels and achieve an optimal bitrate solution. In this study, a reconfigurable, high-performance, low-cost, and real-time ultrasonic data acquisition and signal processing platform is designed based on an all-programmable system-on-chip (APSoC). We designed the unsupervised learning models using wavelet packet transformation optimized by convolutional autoencoder for massive ultrasonic data compression. The proposed learning models can achieve a compression accuracy of 98% by using only 6% of the original data. For ultrasonic signal analysis in NDT applications, we utilized the multilayer perceptron neural network (MLPNN) to detect flaw echoes masked by strong microstructure scattering noise (i.e., about zero dB SNR or less) with detection accuracy above 99%. It is of high interest to characterize materials using ultrasonic scattering properties for grain size estimation and classification. We successfully designed an MLPNN to classify the grain sizes of materials with an accuracy of 99%. Furthermore, a software-defined ultrasonic communication system based on the APSoC is designed for real-time data transmission through solid channels. Transducers with a center frequency of 2.5 MHz are used to transmit and receive information-bearing ultrasonic waves in solid channels where the communication bit rate can reach up to 1.5 Mbps.
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Title: MITOCHONDRIA RELOCALIZATION IN CHLAMYDIA TRACHOMATIS INFECTED HFF-1 CELLS
Creator: Shuppara, Alexander Mitchell
Date: 2021
Description: 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: 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: 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: 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: Sunday Morning in New York
Creator: Lerner, Nathan, 1913-1997
Date: 1943
Description: Photograph includes signed inscription (dated 12/24/1991) from Nathan Lerner to Kiyoko Lerner on verso. Numbered #44.4.3.The date for this...
Show morePhotograph includes signed inscription (dated 12/24/1991) from Nathan Lerner to Kiyoko Lerner on verso. Numbered #44.4.3.The date for this photograph is often listed as 1944 in other sources, the date above was taken from the artist's inscription on the verso of the photo.
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Collection: Nathan Lerner photographs, 1935-1980

Title: Light Drawing - Head
Creator: Lerner, Nathan, 1913-1997
Date: 1939
Description: Light drawing photograph made by moving a light source during a long exposure. Title, date inscribed on verso. Numbered B-21. Mounting...
Show moreLight drawing photograph made by moving a light source during a long exposure. Title, date inscribed on verso. Numbered B-21. Mounting inscribed with title, date and numbered 100, B-21, INV3637, #44
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Collection: Nathan Lerner photographs, 1935-1980

Title: Eye on Nails
Creator: Lerner, Nathan, 1913-1997
Date: 1940
Collection: Nathan Lerner photographs, 1935-1980

Title: Optimo
Creator: Lerner, Nathan, 1913-1997
Date: 1935
Description: Photograph of a cigar store on a Chicago street corner. Unsigned. Numbered 23 on verso.
Collection: Nathan Lerner photographs, 1935-1980

Title: Wire Eyes
Creator: Lerner, Nathan, 1913-1997
Date: 1937-1941
Description: Photograph of what appears to be decorative metalwork in recto of a gravestone or other memorial. Location of photograph unknown. Print...
Show morePhotograph of what appears to be decorative metalwork in recto of a gravestone or other memorial. Location of photograph unknown. Print mounted on cardstock. Signature and date (1941) on recto of cardstock, title and date (1937) on verso. Exact date of photograph unknown. Numbered 759 and 3565 on verso.
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Collection: Nathan Lerner photographs, 1935-1980

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