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Title: Recycling nursery runoff : understanding plant sensitivity to nutrients and residual pesticides
Creator: Poudyal, Shital
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Runoff generated from landscape nursery operations contains agrochemicals such as pesticides and fertilizers, which, if released off-site, may pollute the environment. Nursery producers are increasingly interested in alternatives to using freshwater for irrigation due to increased environmental awareness and reduced water availability. As a result, some progressive nursery growers are already adopting the Runoff generated from landscape nursery operations contains agrochemicals such...
Show moreRunoff generated from landscape nursery operations contains agrochemicals such as pesticides and fertilizers, which, if released off-site, may pollute the environment. Nursery producers are increasingly interested in alternatives to using freshwater for irrigation due to increased environmental awareness and reduced water availability. As a result, some progressive nursery growers are already adopting the Runoff generated from landscape nursery operations contains agrochemicals such as pesticides and fertilizers, which, if released off-site, may pollute the environment. Nursery producers are increasingly interested in alternatives to using freshwater for irrigation due to increased environmental awareness and reduced water availability. As a result, some progressive nursery growers are already adopting the practice of retaining and recycling nursery runoff water for irrigation. While retaining and recycling runoff may be a practical solution, growers' concerns about the potential negative impact of residual pesticides on crop growth and quality still impede its adoption. Therefore the objectives of my studies were to reduce the concentration of nutrients in runoff water and to evaluate the impact of irrigating with recycled runoff water on growth and physiology of nursery crops.The first study was to identify minimum phosphorus concentration required for the optimum morphological and physiological performance in three common woody ornamental taxa; Hydrangea quercifolia (Queen of hearts), Cornus obliqua (Redtwig dogwood) and Physocarpus opulifolius (Seward). The optimum phosphorus concentrations for growth and photosynthetic biochemistry ranged between 4 and 7 mg·L-1, depending on taxa. For the second study, I investigated the response of common landscape nursery plants to residual pesticide commonly found in nursery runoff. Hydrangea paniculata (Limelight), Cornus obliqua (Powell Gardens), Hosta (Gold Standard) were exposed to low residual concentrations of isoxaben, chlorpyrifos and oxyfluorfen, simulating irrigation with nursery runoff. Exposure to oxyfluorfen produced phytotoxicity symptoms (visual leaf damage), while chlorpyrifos and isoxaben did not produce phytotoxicity. Among the three taxa, H. paniculata was the most sensitive species, and C. obliqua was the most resistant. Therefore the effects of pesticides were pesticide-specific and taxa-specific. For the third study, I investigated whether phytotoxicity in response to residual herbicide exposure was dependent on the growth stage of plants. In this study, H. paniculata plants were exposed to a low residual concentration of oryzalin and oxyfluorfen at the various growth stages, starting shorty after bud-break. Residual herbicide exposure had more impact on growth and photosynthetic physiology at early growth stages; however, the recovery rate of those plants was also rapid. For my final study, I conducted three-year field research replicating an actual nursery grower practice of recycling nursery water. Six ornamental species were irrigated with recycled water obtained from a nursery bed receiving ten different pesticides. In addition, the efficacy of woodchip bioreactors to reduced pesticides in water was also tested. Results from this study established the possibility of using recycled water to irrigate ornamentals plants such as Hydrangea macrophylla (Let's dance blue jangles), Hydrangea paniculata (Limelight), Thuja occidentalis (American Pillar), Juniperus horizontalis (Blue rug), Hydrangea arborescens (Invincibelle Spirit II®) and Rosa sp. (Oso Easy Double Red®) without impacting the growth and physiology of those plants. Woodchips bioreactor was also found to be effective in remediating pesticides from water. The results of three greenhouse studies and a field study together provide new information on reducing the concentration of nutrients and pesticides in nursery runoff water and demonstrate the possibility of recycling nursery runoff. The findings of this dissertation are vital in solving the emerging problem of agrochemical pollution and water scarcity that is currently faced by nursery growers.
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Title: Reaction-based knock predictive modeling and model-based stochastic knock limit control of spark-ignition engines
Creator: Li, Ruixue
Date: 2020
Collection: Electronic Theses & Dissertations
Description: This dissertation studies the spark-ignition (SI) engine knock phenomenon, abnormal combustion due to the auto-ignition of end-gas ahead of the propagated flame front, resulting in the rapid chemical energy release with aggressive combustion, limiting the further improvement of thermal efficiency and even damaging the engine mechanically. A control-oriented combustion and pressure wave model with satisfactory accuracy and low computational effort is a necessity for the knock control strategy...
Show moreThis dissertation studies the spark-ignition (SI) engine knock phenomenon, abnormal combustion due to the auto-ignition of end-gas ahead of the propagated flame front, resulting in the rapid chemical energy release with aggressive combustion, limiting the further improvement of thermal efficiency and even damaging the engine mechanically. A control-oriented combustion and pressure wave model with satisfactory accuracy and low computational effort is a necessity for the knock control strategy design. This dissertation develops a control-oriented knock predictive model that includes a two-zone reaction-based combustion model and a pressure wave model. This knock predictive model is capable of accurately describing the combustion process of a spark-ignited engine and predict the in-cylinder pressure oscillations under knocking combustion in real-time. Based on this model, a feedforward and feedback stochastic knock limit control strategy is developed to reduce the knock cyclic variability and control the knock mean-intensity below a desired up bound while keeping spark timing as close to engine maximum brake torque (MBT) timing as possible. A control-oriented two-zone reaction-based model to accurately describe the combustion process of a SI engine is first developed. Instead of using the conventional pre-determined Wiebe-based combustion model, a two-step chemical reaction model is utilized to predict the combustion process along with important thermodynamic parameters such as the mass-fraction-burned, in-cylinder pressure, temperatures and individual species mass changes in both zones. Sensitivities of model parameters are analyzed during the model calibration process. As a result, one set of calibration parameters are used to predict combustion characteristics over all engine operating conditions studied in this paper, which is the major advantage of the proposed method. Also, the proposed modeling approach is capable of modeling the combustion process for real-time simulations. As the by-product of the model, engine knock can also be predicted based on the Arrhenius integral in the unburned zone, which is valuable for model-based knock control. The proposed combustion model is intensively validated using the experimental data with a peak relative prediction error of 6.2% for the in-cylinder pressure. Based on this validated combustion model, a control-oriented pressure wave model for SI engines is further developed. This model is capable of predicting the in-cylinder pressure oscillations under knocking combustion in real-time and can be used for the model-based knock prediction and control. A pressure wave equation including the knock deadening behavior is proposed, simplified, and used to calculate the pressure perturbations generated by the knocking combustion. The boundary and initial conditions at knock onset are analyzed and the analytic solution of the pressure wave equation is obtained. The model is calibrated and validated over two different engine operating conditions at knock limit. The chemical kinetic-based Arrhenius integral (ARI) and the KI20 are used as the evaluation methods for knock onset and intensity prediction, and the knock frequency is studied with a fast Fourier transform of the filtered in-cylinder pressure oscillations. Especially, the knock characteristics associated with gas mixture properties at intake valve closing is analyzed based on the experimental data and their effect to knock cycle-to-cycle variation is also studied for the proposed model. In addition, this dissertation studies the correlation between in-cylinder mixture temperature at intake valve closing and the engine knock, along with knock cyclic variability based on the knock predictive model. A strong correlation between the intake temperature and knock intensity has been obtained and validated based on the simulation investigation and experiment data obtained at knock limit. Therefore, a model-based feedforward and feedback stochastic knock limit control strategy is developed to reduce the knock cycle-to-cycle variability and maintain the knock mean-intensity within a desired up bound by controlling the spark timing as close to MBT timing as possible. The control performance is validated with the simulation results to show the capability of the model-based feedforward and feedback stochastic knock limit control in significantly reducing the knock cyclic variability and improving the knock intensity distribution for the best fuel economy.
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Title: Empowered or entitled to lead? : an evolutionary psychological perspective of how managers navigate structural empowerment
Creator: Lee, Hun Whee
Date: 2020
Collection: Electronic Theses & Dissertations
Description: With the recognition that traditional bureaucratic structures are less likely to respond effectively to volatile and complex business environments, the movement toward structural empowerment has been touted as one of the most significant changes in modern organizations. However, research to date has advanced opposing viewpoints on whether or not structural empowerment will psychologically empower managers and enhance group functioning. The aim of my dissertation is to provide a more nuanced...
Show moreWith the recognition that traditional bureaucratic structures are less likely to respond effectively to volatile and complex business environments, the movement toward structural empowerment has been touted as one of the most significant changes in modern organizations. However, research to date has advanced opposing viewpoints on whether or not structural empowerment will psychologically empower managers and enhance group functioning. The aim of my dissertation is to provide a more nuanced view of the downstream consequences of how managers navigate structural empowerment through the lens of evolutionary psychology. I developed a comprehensive model of how evolved motives for social influence--prestige and dominance--and situational constraints--resource scarcity and outcome interdependence--guide managers' cognition and behavior in the context of structural empowerment. To test my arguments, I utilized experimental (Study 1) and field survey (Study 2) methodologies. My dissertation contributes to the literature in three important ways: 1) I complement the predominant focus on the link between structural empowerment and psychological empowerment by providing accounts for an unintended consequence of structural empowerment, namely entitled managers; 2) my focus on managers' external resource acquisition and sharing as outcomes of structural empowerment expands conceptual boundaries of the role of leadership in the literature; and 3) my dissertation provides an example of how insights from evolutionary psychology can be leveraged to gain a better understanding of why managers do what they do within contemporary organizational structures.
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Title: Immunomodulation by small molecules for prevention or treatment of cancer
Creator: Zhang, Di (Graduate of Michigan State University)
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Cancer is the second leading cause of deaths worldwide. Lung cancer and breast cancer, specifically, are two of the most common cancers in the U.S. except skin cancer. With the increasing medical and economic burden of these diseases, developing effective cancer prevention and treatment strategies is important and urgent. Cancer is characterized by uncontrolled cell proliferation. Targeting the tumor cells directly to inhibit their growth and increase cell death has been the major focus of...
Show moreCancer is the second leading cause of deaths worldwide. Lung cancer and breast cancer, specifically, are two of the most common cancers in the U.S. except skin cancer. With the increasing medical and economic burden of these diseases, developing effective cancer prevention and treatment strategies is important and urgent. Cancer is characterized by uncontrolled cell proliferation. Targeting the tumor cells directly to inhibit their growth and increase cell death has been the major focus of cancer treatment since the last century. Cancer is also described as a wound that does not heal. Inflammation plays critical roles in cancer development and progression. The immune system is a powerful host defense mechanism against infections and diseases including cancer. However, tumor cells are able to edit and suppress the immune system to evade the immune attack. Targeting immune cells to unleash the power of immune surveillance has become a research priority. The recent breakthroughs in cancer immunotherapy have revolutionized the landscape of cancer treatment. As immunotherapy becomes the first line of therapy in cancer treatment, it is essential to understand how other drugs modulate the immune system, so that we can deliver more effective and less toxic combinations. In this thesis project, I focused on four therapeutic targets (bromodomain proteins, retinoid X receptors, Nrf2 transcription factors, poly (ADP-ribose) polymerase) and explored their effects on the immune cells. Small molecules targeting these proteins were tested in various preclinical mouse models in the context of either cancer prevention or treatment. My studies not only demonstrated enhanced efficacy and reduced toxicity with all four classes of compounds but also provided some novel insights into the immunomodulatory effects of these clinically relevant signaling pathways. This work is highly translational and could have direct impact on human patients.
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Title: Online innovization : towards knowledge discovery and achieving faster convergence in multi-objective optimization
Creator: Gaur, Abhinav
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Ì0300nnovization'' is a task of learning common principles thatexist among some or all of the Pareto-optimal solutions in amulti-objective optimization problem. Except a few earlierstudies, most innovization related studies were performed onthe final non-dominated solutions found by an evolutionary multi-objective algorithm eithermanually or by using a machine learning method.Recent studies have shown that these principles can be learnedduring intermediate iterations of an optimization run...
Show moreÌ0300nnovization'' is a task of learning common principles thatexist among some or all of the Pareto-optimal solutions in amulti-objective optimization problem. Except a few earlierstudies, most innovization related studies were performed onthe final non-dominated solutions found by an evolutionary multi-objective algorithm eithermanually or by using a machine learning method.Recent studies have shown that these principles can be learnedduring intermediate iterations of an optimization run and simultaneously utilized in thesame optimization run to repair variables to achieve a fasterconvergence to the Pareto-optimal set. This is what we are calling as ò0300nline innovization'' as it is performed online during the run of an evolutionary multi-objective optimization algorithm. Special attention is paid to learning rules that are easier to interpret, such as short algebraic expressions, instead of complex decision trees or kernel based black box rules.We begin by showing how to learn fixed form rules that are encountered frequently in multi-objective optimization problems. We also show how can we learn free form rules, that are linear combination of non-linear terms, using a custom genetic programming algorithm. We show how can we use the concept of k0300nee' in PO set of solutions along with a custom dimensional penalty calculator to discard rules that may be overly complex, or inaccurate or just dimensionally incorrect. The results of rules learned using this custom genetic programming algorithm show that it is beneficial to let evolution learn the structure of rules while the constituent weights should be learned using some classical learning algorithm such as linear regression or linear support vector machines. When the rules are implicit functions of the problem variables, we use a computationally inexpensive way of repairing the variables by turning the problem of repairing the variable into a single variable golden section search.We show the proof of concept on test problems by learning fixed form rules among variables of the problem, which we then use during the same optimization run to repair variables. Different principleslearned during an optimization run can involve differentnumber of variables and/or variables that arecommon among a number of principles. Moreover, a preferenceorder for repairing variables may play an important role forproper convergence. Thus, when multiple principles exist, itis important to use a strategy that is most beneficial forrepairing evolving population of solutions.The above methods are applied to a mix of test problems and engineering design problems. The results are encouraging and strongly supportsthe use of innovization task in enhancing the convergence of an evolutionary multi-objective optimization algorithms. Moreover, the custom genetic program developed in this work can be a useful machine learning tool for practitioners to learn human interpretable rules in the form of algebraic expressions.
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Title: "My life is changed but the trust ain't there to trust somebody else" : experiences of recovery from intimate partner abuse of women of Mexican heritage in a mid-size city in Michigan
Creator: Palma-Ramirez, Evangelina
Date: 2020
Collection: Electronic Theses & Dissertations
Description: This exploratory qualitative study aimed to gain an understanding of the experiences of recovery from intimate partner abuse (IPA) of 17 women of Mexican heritage in a mid-size urban city in Michigan. IPA was defined as any type of physical, sexual, stalking, psychological harm or coercive control by a former intimate partner or spouse. Two aspects were explored: experiences of abuse and experiences of recovery from abuse. The study used a feminist theory and intersectionality perspective as...
Show moreThis exploratory qualitative study aimed to gain an understanding of the experiences of recovery from intimate partner abuse (IPA) of 17 women of Mexican heritage in a mid-size urban city in Michigan. IPA was defined as any type of physical, sexual, stalking, psychological harm or coercive control by a former intimate partner or spouse. Two aspects were explored: experiences of abuse and experiences of recovery from abuse. The study used a feminist theory and intersectionality perspective as a guiding framework to understand the experiences of women considering their contextual situation. Data were collected using a semi-structured questionnaire and analyzed using a constructivist grounded theory by Charmaz. The findings revealed that women understand their experiences of abuse as being connected to their early socialization about gender roles, history of child abuse, lack of sexual education, and the influence of the environment. Also, the participants revealed they experienced overlapping types of abuse: psychological, coercion, economic, physical, sexual, and stalking. Despite the negative impact of the abuse on participants' physical and mental health, findings showed that women were able to recover from the abuse and to move on with their lives. Data suggested that the recovery was a gradual ongoing process of physical and psychological healing. Participants identified empowering experiences that helped them in their recovery from IPA. Such empowering experiences included life-changing religious realizations, receiving services in Spanish, acquiring more education, receiving counseling services, and getting a job. Receiving social support from family and friends and having access to resources were identified as factors that aided in the recovery from IPA. However, some participants experienced limited access to such resources due to economic constraints, cultural beliefs about gender roles, and the impact of immigration policies.Lastly, findings revealed that experiences of recovery from IPA vary based on whether women decided to leave their partners or to remain with them. Implications for culturally sensitive interventions for Latinas of Mexican heritage are discussed as well as implications for future research on issues of recovery for this specific Latino subgroup.
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Title: Multi-band reconfigurable RFICs in Si-based technologies for a compact and adaptive RF front-end
Creator: Nawaz, Asad Ali
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Recent advances in the wireless communication market have led to the coexistence of several networks such as cellular network, personal area network (PAN), wireless local area network (WLAN), etc. along with several different air interfaces (802.11a, 802.11g, Bluetooth, wireless code division multiple access (WCDMA), etc.). Thus, all the wireless devices need to be compatible with the different communication standards while still keeping similar performance, smaller die area and lower power...
Show moreRecent advances in the wireless communication market have led to the coexistence of several networks such as cellular network, personal area network (PAN), wireless local area network (WLAN), etc. along with several different air interfaces (802.11a, 802.11g, Bluetooth, wireless code division multiple access (WCDMA), etc.). Thus, all the wireless devices need to be compatible with the different communication standards while still keeping similar performance, smaller die area and lower power consumption. The need to enable the "global roaming'' capability between a wide variety of networks operating at different frequencies calls for the development of reconfigurable radio-frequency integrated circuits (RFICs) which can achieve maximum hardware sharing between different standards and across various functions. The objective of this dissertation is to present novel topologies for RF components and blocks that can yield a Si-based frequency-agile RF front-end. The targeted applications for this work are 5G multi-band wireless communication and reconfigurable short/long range phased arrays for automobile radars. However, the concept of the proposed reconfigurable RF elements is generic in nature and can be applied to all emerging applications which require on-chip reconfigurability at microwave and mm-wave frequencies.To demonstrate the concept of a reconfigurable RF front end, a Ka/V band-switchable TRX amplifier is developed in 0.13um BiCMOS SiGe process and a 18-50 GHz receiver is developed in 45nm SOI CMOS process. Unlike the traditional approach for a multi-band radio - where the dedicated single band transceivers composed of fixed RF components are designed and multiplexed with the help of switches - the proposed idea utilizes the switches inside each RF block; thus, adding the reconfigurability inside each block and eliminating the need for separate front-ends. However, the catch in the latter approach is to maintain the RF performance while still being able to save the real estate and power consumption. The proposed Ka/V band-switchable TRX amplifier consists of a band-switchable LNA, a band-switchable PA, and integrated T/R switches which saves a lot of area. The band-switch functionality is realized using thin-film microstrip based shunt stubs with reverse saturated SiGe switches. Design techniques for switch loss reduction and size miniaturizations are presented. This work illustrates that with the optimization of switch loss, appropriate selection of each block between wideband or bandswitching topology and co-design of RF blocks, a highly integrated multi-band transceiver can be designed with the minimal degradation to the RF performance compared to state-of-the-art dedicated single band transceivers. To further explore reconfigurable transceivers, a direct quadrature down-conversion mixer first receiver with active channel select filters has been designed. The receiver supports 200MHz instantaneous RF bandwidth and can be reconfigured to receive any 200 MHz channel within 18-50 GHz frequency range. With the ever-evolving wireless standards like 4G/5G/6G, equipment manufacturers are required to add more functionality into the chips while still maintaining the backward compatibility with previous standards or fallback option to lower frequency bands. A low power, highly integrated, multi-band and multi-standard chipset has thus become a requisite in commercial products. The proposed concept of in-block reconfigurability and the presented design techniques to realize mm-wave frequency reconfigurable transceivers have a huge potential in this regard.
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Title: Development of structurally defined platforms for long-range biological electron transfer
Creator: Huang, Jingcheng (Graduate of Michigan State University)
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Electron transfer reactions are vital for life: they are the essential steps in all the major biological energy conservation pathways and the rate of electron transfer sometimes determines the fate of energy flow. While the rates of electron transfer over 1-2 nanometers in proteins can largely be described by well-known theories, it is not well understood how these processes scale to microscopic distances, for example, micrometer length microbial nanowires. Electron transfer reactions are...
Show moreElectron transfer reactions are vital for life: they are the essential steps in all the major biological energy conservation pathways and the rate of electron transfer sometimes determines the fate of energy flow. While the rates of electron transfer over 1-2 nanometers in proteins can largely be described by well-known theories, it is not well understood how these processes scale to microscopic distances, for example, micrometer length microbial nanowires. Electron transfer reactions are known to be highly sensitive to the chemical properties of the electron carriers and distances between carriers, yet, this information is not available for naturally occurring microbial nanowires. On the other hand, microbial nanowires have inspired the development of novel biological conductive materials and bioelectronics, although these biomimicking materials would significantly benefit from a higher degree of structural definition, which would greatly improve rational redesign.This dissertation work presents two distinct approaches for arranging electron carriers (heme) into structurally defined arrays that can facilitate electron transfer:1) A crystalline lattice of small tetraheme cytochromes that form a well-defined, three-dimensional network of closely spaced redox centers was used to demonstrate the multi-step electron hopping over a micrometer scale.2) A heme attachment strategy was developed that allows one to introduce redox active cofactor hemes into non-heme-binding proteins, while maintaining the proteins' original function. Adding hemes to a nanotube-forming self-assembling protein was used to demonstrate the potential of this strategy to form a structurally defined heme array.The first crystal approach provides detailed information about structure and electronic states which can be used as a platform for testing theories, while the second heme-attaching approach is an engineering platform that allows researchers to introduce redox properties into other well-studied proteins with minimal effort. These two approaches, from two perspectives, lay the foundation of building structurally defined architectures for the understanding of microbial nanowires and the application of biological long-range electron transfer materials.
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Title: ER stress sensor IRE1-alpha and its implications in progression of hepatocellular carcinoma
Creator: Oak, Amrita
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "The endoplasmic reticulum (ER) is the site for protein folding and maturation. ER stressors, both physiological and pharmacological, can result in activation of the unfolded protein response (UPR). Palmitate, a saturated fatty acid, is one such ER stressor and leads to induction of the UPR. This is primarily through the activation of Inositol Requiring Enzyme-1 (IRE1) leading to splicing of XBP1 mRNA. However, the mechanism of this activation is unclear. With the aid of a bimolecular...
Show more"The endoplasmic reticulum (ER) is the site for protein folding and maturation. ER stressors, both physiological and pharmacological, can result in activation of the unfolded protein response (UPR). Palmitate, a saturated fatty acid, is one such ER stressor and leads to induction of the UPR. This is primarily through the activation of Inositol Requiring Enzyme-1 (IRE1) leading to splicing of XBP1 mRNA. However, the mechanism of this activation is unclear. With the aid of a bimolecular fluorescence complementation (BiFC) assay, we identified two crucial residues on the transmembrane domain (TM) of IRE1, S450 and W457, that are drivers of palmitate mediated activation. Previous research from our group suggested that IRE1 also has binding sites for palmitate on its cytosolic domain (CD). However, IRE1-CD protein expressed in E. coli was over-phosphorylated which possibly affected its binding to PA. To investigate this, we developed a protocol for expression and purification of wild type and mutant IRE1-CD protein in insect Sf21 cells. A fluorescence polarization based binding assay was performed to determine whether palmitate binds to residues on the IRE1-CD protein. Previously our laboratory demonstrated that palmitate induced the migration of cancer cells as well as transcription factors (TF) involved in epithelial-to-mesenchymal transition (EMT). Here, we investigated the role of IRE1 activation on these processes. Using CRISPR gene editing to generate IRE1 knockouts in liver and breast cancer cell lines, we observed that IRE1 mediates the upregulation in EMT-TFs, a decrease in the expression of the desmoplakin (DSP) protein, and an increase in the migration of liver and breast cancer cells. DSP is a critical component of desmosomes, which function to maintain the structural integrity at adjacent cell-cell contacts.In addition to migration, the effect of XBP1 splicing on metabolism has not been studied. We found the activation of IRE1-XBP1 is accompanied by changes in the metabolic genes involved in glycolysis, fatty acid oxidation, gluconeogenesis, and ceramide metabolism, suggesting that some of the metabolic effects of palmitate are mediated through IRE1. These results could have implications on the development of chemotherapeutic strategies. This study paves the way for further investigations into the far-reaching effects of activation of the UPR on cell survival, metabolism, and chemo-tolerance."--Pages ii-iii.
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Title: Interpretable machine learning in plant genomes : studies in modeling and understanding complex biological systems
Creator: Azodi, Christina Brady
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Complex systems are ubiquitous in genetics and genomics. From the regulation of gene expression to the genetic basis of complex traits, we see that complex networks of diverse cellular molecules underpin the natural world. Driven by technological advances, today's researchers have access to large amounts of omics data from diverse species. At the same time, improvements in computer processing and algorithms have produced more powerful computational tools. Taken together, these advances mean...
Show moreComplex systems are ubiquitous in genetics and genomics. From the regulation of gene expression to the genetic basis of complex traits, we see that complex networks of diverse cellular molecules underpin the natural world. Driven by technological advances, today's researchers have access to large amounts of omics data from diverse species. At the same time, improvements in computer processing and algorithms have produced more powerful computational tools. Taken together, these advances mean that those working at the interface of data science and biology are poised to better model and understand complex biological systems. The research in this dissertation demonstrates how a data-driven approach can be used to better understand three complex systems: (1) transcriptional response to single and combined heat and drought stress in Arabidopsis thaliana, (2) the genetic basis of flowering time, a complex trait, in Zea mays, and (3) the social basis for opinions and beliefs about biotechnology products.To study the first system, we generated models of the cis-regulatory code from information about DNA sequence and additional omics levels using both classic machine learning and deep learning algorithms. We identified 1,061 putative cis-regulatory elements associated with different patterns of response to single and combined heat and drought stress and found that information about additional levels of regulation, especially chromatin accessibility and known transcription factor binding, improved our models of the cis-regulatory code. To study the second system, we generated phenotype prediction models for flowering time, height, and yield based on either genetic markers or transcript levels at the seedling stage. We found that, while genetic marker-based models performed better than transcript level-based models, models that integrated both types of data performed best. Furthermore, transcript-based models were more useful for finding genes known to be associated with flowering time, highlighting how using additional levels of omics data can improve our ability to understand the genetic basis of complex traits. Finally, to study the third system, we integrated 29 characteristics about a person (e.g. age, political ideology, education, values, environmental beliefs) into a machine learning model that would predict an individual's beliefs and opinions about five different types of biotechnology products (e.g. biofortification, biopharmaceuticals). While this approach was particularly usefully for identifying individuals that were broadly supportive of biotechnology, finding characteristics of individuals with negative or conditional (i.e. support product A, but not B) opinions was more challenging, highlighting the complexity of public opinions about biotechnology.
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Title: Mitochondrial function does not limit aerobic metabolism in type 2 diabetes : magnetic resonance studies in the Goto-Kakizaki rat
Creator: Lewis, Matthew T.
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "Type 2 diabetes (T2D) is a growing health concern with nearly 400 million affected worldwide as of 2014 (418). T2D presents with hyperglycemia and insulin resistance resulting in increased risk for blindness, renal failure, nerve damage and premature death (10). Skeletal muscle is a major site for insulin resistance and is responsible for up to 80% of glucose uptake during euglycemic hyperinsulinemic clamps (89). Glucose uptake in skeletal muscle is driven by mitochondrial oxidative...
Show more"Type 2 diabetes (T2D) is a growing health concern with nearly 400 million affected worldwide as of 2014 (418). T2D presents with hyperglycemia and insulin resistance resulting in increased risk for blindness, renal failure, nerve damage and premature death (10). Skeletal muscle is a major site for insulin resistance and is responsible for up to 80% of glucose uptake during euglycemic hyperinsulinemic clamps (89). Glucose uptake in skeletal muscle is driven by mitochondrial oxidative phosphorylation (MOP) and for this reason mitochondrial dysfunction has been implicated in T2D (225). Mitochondrial function in this sense is defined as the capacity for skeletal muscle mitochondria to produce ATP. In the present document, skeletal muscle mitochondrial function and its limitations were studied utilizing the Goto-Kakizaki (GK) rat model of type 2 diabetes. Mitochondrial function was defined computationally demonstrating the relationship between the drivers of ATP production (ADP, Pi) and ATP production itself. Computational depiction of MOP allowed for a functional understanding of any changes in mitochondrial function. Quantification of mitochondrial function demonstrated deficits during high metabolic workloads in the GK rat. However, upon closer analysis utilizing both computational and in vitro techniques results suggested that metabolic deficits were due to limitations separate from mitochondrial dysfunction. Since MOP ATP production requires oxygen utilization by the mitochondria and oxygen supply to the mitochondria, oxygen deficits may present in the same fashion as dysfunctional mitochondria and thus the most logical explanation to target for dysregulation was a limitation in oxygen supply. For this reason, cardiovascular function was measured in the conscious GK rat utilizing an array of challenges. Results showed no deficits in skeletal muscle performance at low workloads consistent with measures of normal mitochondrial function. However, measures indicated a harder working heart along with cardiovascular disease risk factors that may cause blood flow limitations during high intensity workloads. Quantification of blood flow using the identical setup that measured mitochondrial function during hindlimb contraction showed reductions in blood flow that could limit MOP during high intensity workloads in the diabetic GK rat. Taken together this culmination of works suggests that mitochondrial dysfunction is not inherent to type 2 diabetes, but rather muscle metabolic deficits manifest from blunted oxygen supply. This result is crucial to advance therapeutic interventions in type 2 diabetes and similar experiments in humans may direct drug therapies away from targeting skeletal muscle mitochondria and towards improving skeletal muscle blood flow."--Pages ii-iii.
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Title: Genetic mapping of resistance to soybean sudden death syndrome and soybean oil quality
Creator: Collins, Paul Joseph
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "Soybean (Glycine max) is the world's leading oilseed crop and is a critical source of protein for poultry and swine production. Soybean production is limited by many biotic factors including soybean sudden death syndrome (SDS) which is caused by a soil-borne fungal pathogen, Fusarium virguliforme. Effective management methods for soybean sudden death syndrome include long-term rotations, fluopyram seed treatment, and planting SDS resistant varieties. Host resistance to F. virguliforme is a...
Show more"Soybean (Glycine max) is the world's leading oilseed crop and is a critical source of protein for poultry and swine production. Soybean production is limited by many biotic factors including soybean sudden death syndrome (SDS) which is caused by a soil-borne fungal pathogen, Fusarium virguliforme. Effective management methods for soybean sudden death syndrome include long-term rotations, fluopyram seed treatment, and planting SDS resistant varieties. Host resistance to F. virguliforme is a quantitative resistance, as it is controlled by many genes, largely of small effect. To more efficiently breed SDS resistant soybean varieties, researchers have sought to identify the loci on the soybean genome responsible for SDS-resistance. Three recombinant inbred line (RIL) populations were evaluated for foliar SDS resistance at a naturally infested field site in Decatur, MI during the 2014 and 2015 growing seasons. These populations segregated for SDS resistance, as they were derived from a parent resistant to SDS and a parent susceptible to SDS. The parents and a subset of RILs from each population were genotyped with the SoySNP6K Illumina Infinium BeadChip. Linkage maps unique to each population were constructed using JoinMap ver. 2. Composite interval mapping was done using WinQTLCartographer (ver. 2.5). Six quantitative trait loci (QTL) were identified to be associated with SDS resistance. Three of the QTL associated with SDS resistance were identified across multiple years and/or populations. While biotic factors, such as SDS, work to limit soybean production, soybean quality factors, such as oil quality, can offer new production opportunities. Soybean oil is predominantly composed of five fatty acids: palmitic acid (11%), stearic acid (4%), oleic acid (25%), linoleic acid (52%), and linolenic acid (8%). While there is little variability in most commodity soybean varieties for fatty acid content, soybean breeders have been able to introduce oil quality traits into the soybean germplasm. Oil quality traits for soybean oil include high oleic acid content (>75%), low linolenic acid content (<3%), and low saturated fat content (palmitic + stearic < 8%). A RIL population was developed by crossing a high oleic acid, low linolenic acid, and low saturated fat content public variety (E16831) with a high yielding line with a commodity soybean fatty acid profile (E12076T). The parents, the RIL population, and bulked pools representing extreme phenotypes were genotyped with the SoySNP6K Illumina Infinium BeadChip, a linkage map was developed using JoinMap (v.2), and QTLs were detected using WinQTLCartographer (v 2.5). The study confirmed the effects of many known fatty acid biosynthesis genes including GmFAD2-1B, GmFAD3A, GmFAD3B, GMFAD3C, and GmFATB-1A. The study was also able to dissect possible strategies and limitations of marker assisted selection (MAS) for the development of soybean varieties with high oleic acid, low linolenic acid, and low saturated fat content."--Pages ii-iii.
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Title: Quantifying differences in otolith chemistry of Chinook salmon in Lake Michigan to determine natal origins
Creator: Maguffee, Alexander C.
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Previous research has indicated that a substantial amount of hatchery-reared Chinook salmon (Oncorhynchus tshawytscha) migrate from Lake Huron to Lake Michigan, likely due to greater foraging opportunities in Lake Michigan, indicating the potential for wild Chinook salmon to exhibit similar movement patterns. Thus, an increased priority has been placed on quantifying the movement of wild Chinook salmon from Lake Huron to Lake Michigan. The goal of this research was to determine the...
Show morePrevious research has indicated that a substantial amount of hatchery-reared Chinook salmon (Oncorhynchus tshawytscha) migrate from Lake Huron to Lake Michigan, likely due to greater foraging opportunities in Lake Michigan, indicating the potential for wild Chinook salmon to exhibit similar movement patterns. Thus, an increased priority has been placed on quantifying the movement of wild Chinook salmon from Lake Huron to Lake Michigan. The goal of this research was to determine the feasibility of quantifying inter-basin movement of wild Chinook salmon using otolith microchemistry techniques. Chinook salmon otolith pairs were extracted from juvenile and adult fish collected in 2015 and 2016 from tributaries in six predefined regions. Otoliths were analyzed using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA ICP MS) to determine trace metal concentrations, and various multivariate classification algorithms were evaluated for accuracy of classification. Juvenile data reclassified to their natal regions with classification success at a basin level comparable to previous Great Lakes otolith studies. Applying the juvenile-fit models to the adult data resulted in moderate success at a basin level. MANOVAs indicated significant differences in otolith microchemistry between juvenile year classes, and these differences negatively affected classification accuracy. These findings suggest that otolith microchemistry can be used to estimate wild Chinook salmon inter-basin movement, and that classification accuracy will be much higher if the model is developed from the same year class as the assessment sample.
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Title: Privilege-based decentralized data sharing
Creator: Zaghloul, Ehab
Date: 2020
Collection: Electronic Theses & Dissertations
Description: In this dissertation, cryptographic mechanism-based data sharing schemes are presented that address the challenges of dependence on third trusted parties to facilitate sensitive data sharing and censorship. This work is driven by the lack of elevated security and privacy countermeasures necessary for use with sensitive data that many third parties exhibit. Our proposed schemes transition from centralized to distributed models, thus alleviating trust on third parties to realize data owner...
Show moreIn this dissertation, cryptographic mechanism-based data sharing schemes are presented that address the challenges of dependence on third trusted parties to facilitate sensitive data sharing and censorship. This work is driven by the lack of elevated security and privacy countermeasures necessary for use with sensitive data that many third parties exhibit. Our proposed schemes transition from centralized to distributed models, thus alleviating trust on third parties to realize data owner sharing preferences.We first propose a secure Privilege-based Multilevel Organizational Data sharing (P-MOD) scheme that uses the cloud as a storage medium. P-MOD integrates a privilege-based access structure into an attribute-based encryption mechanism to facilitate sensitive data sharing in hierarchical settings. This structure allows data owners to share their sensitive data selectively among all levels of the hierarchy in a fine-grained manner. It also reduces computational complexity by minimizing the overall cryptographic operations. Following the development of P-MOD, we wished to gain a better understanding of distributed systems in an effort to eliminate the need to trust third parties. Therefore, we conducted a comprehensive study of the first system to adopt blockchain, Bitcoin. In this study, we aimed to identify the security points of weakness of these distributed systems. We delved deeply into one of the major security threats, double-spending attacks, by performing two thorough probability analyses of its likelihood of success. Next, we conducted a probability of success versus profitability analysis of double-spending attacks to investigate the trade-offs between waiting time before accepting a transaction and the profitability of these attacks.Motivated by our study of blockchain and the underlying foundation of distributed peer-to-peer (P2P) networks, we developed a distributed Multilevel Attribute-based EMR management (d-MABE) scheme based on our groundwork of P-MOD. The d-MABE scheme incorporates smart contracts deployed and executed over the blockchain to ensure the data sharing preferences of the data owners are maintained. It also replaces the cloud storage with a distributed storage system that is managed by a P2P network to improve the reliability of retrieving data when requested. Using electronic medical records (EMR) as a use-case, our goal is to demonstrate the benefits of alleviating dependence on the electronic record-generating institutions and thus granting data owners (patients) control of their sensitive data in a distributed manner.To further expand our research and reflect its applicability to a wider domain space, we proposed a blockchain-based distributed Coercion-Resistant and Anonymous Mobile Electronic (d-CRAME) voting scheme. The proposed scheme is secure and preserves voter privacy through secure multi-party computations performed by parties of differing allegiances. It also leverages a blockchain running smart contracts as a publicly accessible and tamper-resistant bulletin board to permanently store votes and prevent double-voting. Using voting as an application, our goal is to demonstrate the potential and feasibility of designing a distributed and remote voting scheme for large-scale elections, thus increasing voter turnout and accuracy in the decision-making process.
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Title: Insights into the photophysical reaction coordinate of 1st row transition metal chromophores from vibrational coherences
Creator: Paulus, Bryan Christopher
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Controlling the processes which occur following absorption of photon is beneficial for any conceivable application which seeks to convert light into chemical potential. Transition metal chromophores often undergo ultrafast photoinduced transformations which involve significant nuclear motion. This intricate relationship between electronic and nuclear degrees of freedom suggests significant mixing of their wavefunctions and an interdependence of these molecular properties that can map onto the...
Show moreControlling the processes which occur following absorption of photon is beneficial for any conceivable application which seeks to convert light into chemical potential. Transition metal chromophores often undergo ultrafast photoinduced transformations which involve significant nuclear motion. This intricate relationship between electronic and nuclear degrees of freedom suggests significant mixing of their wavefunctions and an interdependence of these molecular properties that can map onto the photophysical dynamics. In systems such as these, the rich dynamical information encoded in vibrational coherences can in principle provide unique insight into the nature of this coupling. Furthermore, this has the potential to provide subtle clues for how one could exert some degree of kinetic control through informed structural, compositional, and environmental modifications. This dissertation describes efforts to use excited state vibrational coherences to glean mechanistic information about ultrafast excited state decay in several first-row transition metal chromophore systems and, further, to exploit that information to reengineer the chromophore to alter the photophysical properties.This dissertation begins by using ultrafast transient absorption measurements to provide an updated kinetic model for a series of chromium(III) tris-betadiketonate compounds. Following prompt 4T2 → 2E ISC to the lowest energy excited state, thermally activated back-intersystem crossing repopulates the 4T2 state which internally converts to the ground state on the 10303 ps timescale. Steric bulk in the periphery of the molecule reduces the rate of internal conversion resulting in significantly different spectral evolution. Identical low frequency symmetric breathing modes with dephasing times ranging from 2003030-2500 fs were identified in the 2E excited state of each molecule. The more rapid dephasing times are likely due to IVR. Similar methodology was then used to characterize the excited state dynamics in a structurally related series of cobalt(III) tris-betadiketonate compounds. Following ligand field excitation into the 1T1g state, each compound had essentially identical biphasic kinetics with ground state recovery occurring with a 2 0303ps time constant from an excited state of (t2g)5(eg*) electron configuration. Low frequency metal-ligand breathing modes similar to those observed in the chromium systems were observed with dephasing times consistently on the order of 2003030 fs.Finally, two methods to elongate MLCT lifetimes of iron(II) polypyridyl compounds were demonstrated. In the first, the vibrational modes which drive the ultrafast, sub-200 fs MLCT deactivation to the lower energy metal-centered excited states in a [Fe(cage)]2+ control molecule were identified by their coherent oscillations in a transient absorption experiment. These modes were subsequently hindered by incorporation of electronically benign copper(I) atoms to the N4 coordination environments in the periphery of the ligand scaffold resulting in a > 20-fold increase in the MLCT lifetime. In the final study, it was shown that the excited state properties of iron(II) polypyridyl type systems can be systematically and dramatically tuned by swapping out a single bidentate phenanthroline ligand of a [Fe(phen)3]2+ control molecule with stronger-field cyanide or acyclic dicarbene ligands. This modular approach to tuning the kinetics resulted in a > 25-fold increase in the MLCT lifetime and a fundamentally different decay pathway.
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Title: Analysis of the petrology and geochemistry of the magmas of the Galema range in the Somalian Plateau, Ethiopia : a probe of lithospheric processes of the northern east African rift system
Creator: Chiasera, Brandon
Date: 2020
Collection: Electronic Theses & Dissertations
Description: As a continental rift evolves towards a mid ocean ridge, the continental lithosphere must rupture and extension must become accommodated exclusively by seafloor spreading. During this process, extensional strain is initially accommodated along the nascent rift margins, subsequently localizing to zones of focused magmatic intrusion. Asthenospheric conditions such as increased mantle potential temperature or presence of an upwelling, deep seated mantle anomaly may influence, or be responsible...
Show moreAs a continental rift evolves towards a mid ocean ridge, the continental lithosphere must rupture and extension must become accommodated exclusively by seafloor spreading. During this process, extensional strain is initially accommodated along the nascent rift margins, subsequently localizing to zones of focused magmatic intrusion. Asthenospheric conditions such as increased mantle potential temperature or presence of an upwelling, deep seated mantle anomaly may influence, or be responsible for, these extensional processes. While these processes are integral in the process of continental rifting, how they relate and influence each other remains an area of active scientific inquiry and debate. The Main Ethiopian Rift (MER) in East Africa is the ideal location to study extensional processes. We examine the Galema range, an area of focused magmatic activity along the eastern margin of the Central Main Ethiopian Rift, which is morphologically similar to areas of focused magmatism within the rift. To better understand the complex processes involved in continental rifting and how they are related, we present whole-rock, major and trace element data on 77 samples of the Galema range magmas, including isotopic geochemistry on 22 of these samples. We find that whole rock thermodynamic modeling and thermobarometric calculations on mineral-liquid pairs suggest that fractionation (and hence magma stalling depths) within the Galema range is polybaric (70303 and 30303 kbar). These results, when compared to zones of focused intrusion within the rift, indicate an incipient magmatic plumbing system. Trace element models of melt generation reveal melting conditions of 1418-1450°C at 2.9-3.2 GPa. These conditions reveal that Ethiopian mantle TP is elevated by 603038-100°C over ambient. In contrast, Si/Mg activity thermobarometry, which probes the point at which these magmas last re-equilibrated with the mantle, yielded broadly similar temperatures (1435-1474°C) but at lower pressures (2.1-2.6 ± 0.2 GPa). We interpret these results as evidence for magma stalling at a thermo-mechanical boundary to ascent, which we contend is the lithosphere-asthenosphere boundary (LAB). Isotopic analyses of the magmas of the Galema range indicate the presence of signatures of the Afar plume, Pan-African lithosphere, and depleted mantle. A subset of these isotopic analyses indicates the presence of a previously unknown, 4th mantle end member, which we attribute to be a contribution from a recently created, and destroyed, sub-continental lithosphere beneath the eastern Ethiopian plateau. We contend that diking associated with the Galema range, which pre-dates magmatic belts within the rift; thermomechanically modified the lithosphere along this margin. The thermomechanical modification of the lithosphere mantle along this margin facilitated the subsequent development of within-rift magmatic chains. The implications of this are that off-rift magmatic activity may play an integral role in facilitating the development of rift architecture. We interpret contrasting results between two trace element modeling approaches as evidence for magma ponding subsequent to melt generation. While the continental lithosphere has thinned during extension, the lithosphere remains relatively thick late into the rifting process, despite the development of magmatic extension at crustal depths. The presence of an isotopic signature of a sub-continental lithospheric mantle indicates rapid creation and destruction of lithospheric material in processes attributed to the upwelling Afar plume. This process may be one way in which the lithosphere is thinned in the EARS, along with foundering and assimilation of material into the depleted asthenosphere.
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Title: Fluid reasoning as a predictor of deviant workplace behaviors
Creator: Matusik, James Garrett
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Relative to the sizable body of work investigating the relationship between intelligence and task performance, one facet of overall job performance, very little research has been conducted on the relationship between intelligence and counterproductive work behavior, a different but equally important facet of job performance. Furthermore, the little research that has been conducted on the intelligence-counterproductive work behavior relationship has yielded entirely inconsistent results -...
Show moreRelative to the sizable body of work investigating the relationship between intelligence and task performance, one facet of overall job performance, very little research has been conducted on the relationship between intelligence and counterproductive work behavior, a different but equally important facet of job performance. Furthermore, the little research that has been conducted on the intelligence-counterproductive work behavior relationship has yielded entirely inconsistent results - while some researchers have found a negative relationship between intelligence and counterproductive work behavior, others have found null or positive relationships. This, coupled with the reality that none of these studies have explicitly tested causal mechanisms, provides us with an entirely unclear understanding of this relationship. Thus, the goal of this dissertation is to more carefully examine the potential relationship(s) between intelligence and counterproductive work behavior by (a) capturing both overt and covert counterproductive work behaviors, (b) testing a previously identified, but thus far untested, mediating mechanism, and (c) incorporating moderators, selected based upon criminology research that has leveraged a psychological approach in the explanation of individual deviance.
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Title: Perturbations of the sensible : an atlas of mathematics education research
Creator: Dubbs, Christopher Harold
Date: 2020
Collection: Electronic Theses & Dissertations
Description: The field of mathematics education does not exist per se, but rather is the product of many people writing around some (disparate) ideas that have congealed into the semblance of a thing that looks solid, that looks fixed, but really is a foam: a volatile substance made from many bubbles emerging, popping, merging, and splitting. Following in the genealogical tradition of Michel Foucault, I look back at the emergence of this field called mathematics education research (foam) to trace the...
Show moreThe field of mathematics education does not exist per se, but rather is the product of many people writing around some (disparate) ideas that have congealed into the semblance of a thing that looks solid, that looks fixed, but really is a foam: a volatile substance made from many bubbles emerging, popping, merging, and splitting. Following in the genealogical tradition of Michel Foucault, I look back at the emergence of this field called mathematics education research (foam) to trace the emergence of foci of study (bubbles). From the focus on teaching and learning and achievement differences in the 1970s to issues of inclusion, racial equity, and critical research methods in the 2010s, the foci of the field have not been fixed. This shift, the fluid nature of an evolving field gives me hope. What mathematics education research is is not a natural inevitability, but the product of human action, the collision of incident, orthogonal, and/or opposite forces, and its trajectory is tied to its origins, yet not deterministically.What has been done in the name of mathematics education research is not its natural inevitability but the product of these collisions of forces, this popping, merging, and splitting of bubbles, and those certain foci have merely gained dominance, imbuing them with a state of presumed inevitability. Since there is no natural start/origin, there is no naturally inevitable conclusion/destination and the field can grow in new/different/unexpected ways. By looking at those articles published between 1970 and 2019 in the Journal for Research in Mathematics Education (JRME), as well as those published since 2010 in for the learning of mathematics (flm) and Educational Studies in Mathematics (ESM), I provide a tracing of a field called mathematics education research. By mapping the citation relationships of these articles and their references in their entirety, I will identify the bubbles of research in each decade of interest (five from the JRME and one from each of flm and ESM). In addition, I will identify the bubbles that together constitute the foam of the field: the bubbles correspond to the different foci that, put together, share borders.Borrowing on Jacques Ranciere's distribution of the sensible, I believe that the field, as it has been, limits what we can say is mathematics education research, see as counting as mathematics education research, think as mathematics education, and do in the name of mathematics education research. These limits on what can be seen, said, thought, and done in the name of mathematics education research, what is (non)sensical, constitute a distribution of the sensible. This dissertation serves as a perturbation of those sensible limits.What follows in this dissertation is an elaboration of my theoretical orientations towards the field of mathematics education research itself: what constitutes the (im)possible, the (non)sensical, and the (im)proper. Then, I introduce graph theory though an introduction of citation network research methods, coupling both theories on the development of fields of research and computational methods for implementing citation network research. The methods, while I include their mathematical roots, will be presented by way of practicality: what software can accomplish which tasks with relative ease. Then, once the theories and methods are unpacked, the maps, the citation networks, will be presented at both bubble (micro-perspective of research foci) and foam (macro-perspective of what the bubbles together constitute) levels. These maps of the bubbles and foams (1970s-2010s JRME, 2000s flm, 2000s ESM) together constitute an atlas of mathematics education research as it has been and how it has evolved from the 1970s to today. Drawing on the genealogic process of Foucault, I conclude by celebrating the fact that what has been, and what currently is, is neither natural nor inevitable. Therefore, what can be in mathematics education research is limited only by our imaginations as a field.
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Title: The Mexican worker : a Marxist reading of labor struggles in Californian Chicano/a literature
Creator: Medina, Felix
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The purpose of this dissertation is to examine the representation of labor struggles in Chicano/a literature, through a Marxist lens. This study examines how the Chicano/a literary works selected offer criticisms on the treatment of Mexican laborers within capitalism, and how these Chicano/a authors historicize the racialization and proletarianization of Mexicans within U.S. capitalism. Marxist theory allows to understand how Mexican bodies and their labor become (de)valued within capitalism...
Show moreThe purpose of this dissertation is to examine the representation of labor struggles in Chicano/a literature, through a Marxist lens. This study examines how the Chicano/a literary works selected offer criticisms on the treatment of Mexican laborers within capitalism, and how these Chicano/a authors historicize the racialization and proletarianization of Mexicans within U.S. capitalism. Marxist theory allows to understand how Mexican bodies and their labor become (de)valued within capitalism depending on the needs of businessmen and the American government, thus becoming commodities themselves. -- Abstract.
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Title: The strengths and needs of Palestinian youth : perspectives of youth service providers in Bethlehem, Palestine
Creator: Al-Zoughbi, Lucas
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Background: Palestinian youth are subject to a reality predicated on political and social injustice. The extant literature tends to view these youth through a deficit lens without adequate contextualization. This study aims to address this gap by documenting Palestinian youth strengths, challenges, and root causes according to youth-service providers. Methods: We conducted interviews with youth-service providers in the Bethlehem area. Interviews were followed by a member-checking survey to...
Show moreBackground: Palestinian youth are subject to a reality predicated on political and social injustice. The extant literature tends to view these youth through a deficit lens without adequate contextualization. This study aims to address this gap by documenting Palestinian youth strengths, challenges, and root causes according to youth-service providers. Methods: We conducted interviews with youth-service providers in the Bethlehem area. Interviews were followed by a member-checking survey to improve accurate capture of their experiences. Results: Utilizing Graneheim and Lundman's (2004) pragmatic qualitative data analysis, we extracted nuanced themes that mapped onto the analytical categories. We identified five analytical categories: educational, societal, political, economic, and individual. Discussion: Our findings suggest a complex and nuanced perspective of Palestinian youth according to youth service providers in the Bethlehem area. We discuss implications for practitioners and researchers interested in youth development and well-being in the Palestinian context.
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