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Title: A follow-up study of former students enrolled in agriculture in Flathead county high school, Kalispell, Montana during the period 1913 to 1949
Creator: Robinson, Henry Edward
Date: 1952
Collection: Electronic Theses & Dissertations

Title: Statistical and computational methods for biological data
Creator: Hao, Yuning
Date: 2019
Collection: Electronic Theses & Dissertations
Description: The development of biological data focuses on machine learning and statistical methods. In immunotherapy, gene-expression deconvolution is used to quantify different types of cells in a mixed population. It provides a highly promising solution to rapidly characterize the tumor-infiltrating immune landscape and identify cold cancers. However, a major challenge is that gene-expression data are frequently contaminated by many outliers that decrease the estimation accuracy. Thus, it is imperative...
Show moreThe development of biological data focuses on machine learning and statistical methods. In immunotherapy, gene-expression deconvolution is used to quantify different types of cells in a mixed population. It provides a highly promising solution to rapidly characterize the tumor-infiltrating immune landscape and identify cold cancers. However, a major challenge is that gene-expression data are frequently contaminated by many outliers that decrease the estimation accuracy. Thus, it is imperative to develop a robust deconvolution method that automatically decontaminates data by reliably detecting and removing outliers. Our development of an algorithm called adaptive Least Trimmed Square (aLTS) identifies outliers in regression models, allows us to effectively detect and omit the outliers, and provides us robust estimations of the coefficients. For the guarantees of the convergence property and parameters recovery, we also included certain theoretical results.Another interesting topic is the investigation of the association of phenotype responses with the identified intricate patterns in transcription factor binding sites for DNA sequences. To address these concerns, we pushed forward with a deep learning-based framework. On one hand, to capture regulatory motifs, we utilized convolution and pooling layers. On the other hand, to understand the long-term dependencies among motifs, we used position embedding and multi-head self-attention layers. We pursued the improvement of our model's overall efficacy through the integration of transfer learning and multi-task learning. To ascertain confirmed and novel transcription factor binding motifs (TFBMs), along with their relationships internally, we provided interpretations of our DNA quantification model.
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Title: Variation in feed efficiency and carcass characteristics of individually fed swine
Creator: Vorkapich, Mike
Date: 1955
Collection: Electronic Theses & Dissertations

Title: Role of propionate and uncouplers of oxidative phosphorylation on hepatic metabolism and feeding behavior in dairy cows
Creator: Kennedy, Katherine Marie
Date: 2019
Collection: Electronic Theses & Dissertations
Description: The negative energy balance of dairy cows in the postpartum period is exacerbated by a suppression in appetite. Metabolic diseases resulting from negative energy balance can decrease milk production, health and fertility, increasing risk of culling. Research suggests that feeding behavior is linked to the oxidation of fuels in the liver and that an increase in oxidation of fuels causes satiety. Propionate derived from the fermentation of starch in the rumen is a major glucose precursor in...
Show moreThe negative energy balance of dairy cows in the postpartum period is exacerbated by a suppression in appetite. Metabolic diseases resulting from negative energy balance can decrease milk production, health and fertility, increasing risk of culling. Research suggests that feeding behavior is linked to the oxidation of fuels in the liver and that an increase in oxidation of fuels causes satiety. Propionate derived from the fermentation of starch in the rumen is a major glucose precursor in dairy cows but can also cause hypophagia. Because propionate is anaplerotic, it stimulates the oxidation of fuels in the liver, likely causing the hypophagic effects. In order to determine the role of anaplerotic metabolites and uncouplers of oxidative phosphorylation on hepatic metabolism and feeding behavior in dairy cows, 6 studies were conducted. First, using 8 dairy cows in a duplicated 4x4 Latin square design, the effect of feed status (before or after access to feed) on the hepatic extraction and metabolism of propionate over 20 min was determined. The results indicated that hepatic extraction and metabolism of propionate is very rapid, and that metabolite concentrations were greater after compared with before feeding. Additionally, potential bottlenecks of propionate metabolism were identified. Secondly, a study using hepatic explants incubated in [13C3]sodium propionate was conducted to test the effects of 3 different concentrations of propionate (1, 2 or 4 mM) on propionate metabolism over 60 min. An increased concentration of propionate in the range from 1 - 4 mM resulted in the conversion of propionate to acetyl CoA, likely through pyruvate, and that the acetyl CoA was incorporated into the TCA cycle for oxidation. Additionally, metabolism of [13C3]propionate occurred rapidly with significant increases of 13C enrichment detected within 0.5 min for many metabolites. Furthermore, uncoupling the electron transport chain should affect the metabolism of propionate and the feeding behavior of dairy cows as a result of inefficient oxidation of fuels. The effects of two uncouplers of oxidative phosphorylation, 2,4-dinitrophenol methyl ether (DNPME) and sodium salicylate (SAL), on feeding behavior in dairy cows were determined in 2 experiments. Treatment with DNPME and SAL decreased eating rate in dairy cows over the first 4 h following access to feed. Additionally, DNPME increased meal length over the first 4 h following access to feed. Lastly, an experiment was conducted to determine the effects of DNPME and SAL on metabolism and oxidation of propionate over 60 min using hepatic explants from 8 dairy cows. Neither DNPME nor SAL increased oxidation. The DNPME treatment did not alter metabolism of propionate except for an increase of propionate converted to succinyl CoA, however, SAL decreased glucose synthesis from propionate. From this research, we conclude that hepatic metabolism of propionate occurs rapidly and is likely having effects on feeding behavior within minutes as well. As such, the importance of short-term metabolism in regard to feeding behavior and dry matter intake should be considered in future research. Understanding the mechanisms for metabolic control of feed intake will lead to development of novel nutritional or pharmacological approaches to increase energy intake, health, and milk yield of dairy cows; thus, improving nutrient utilization and sustainability of the dairy industry.
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Title: Tailoring the growth and electronic structure of organic molecular heterointerfaces
Creator: Tan, Andrew W. J.
Date: 2019
Collection: Electronic Theses & Dissertations
Description: In the rapidly developing electronics industry, it has become increasingly necessary to explore materials that are cheap, flexible and versatile which have led to significant research efforts towards organic molecular thin films. Understanding and control of heterointerface between highly ordered organic molecular thin films with extended π systems and inorganic materials are therefore of critical importance for the development of modern organic electronics. Organic molecules are unique...
Show moreIn the rapidly developing electronics industry, it has become increasingly necessary to explore materials that are cheap, flexible and versatile which have led to significant research efforts towards organic molecular thin films. Understanding and control of heterointerface between highly ordered organic molecular thin films with extended π systems and inorganic materials are therefore of critical importance for the development of modern organic electronics. Organic molecules are unique compared to their inorganic atomic counterparts as their properties can be tuned drastically through chemical functionalization, offering versatility, though their extended shape and weak intermolecular interactions bring significant challenges to the control of both the growth and the electronic structures of molecular thin films. This is further complicated by interaction between organic molecules and the underlying substrate which can lead to interfacial effects such as charge transfer, chemical interaction and electrostatic screening, all of which can significantly impact device performance and/or the characteristic of the organic thin film. This dissertation will first focus on a systematic review of the growth and electronic structure of organic molecular thin films, particularly on weakly interacting substrates. The self-assembly process and how long-range ordered organic molecular thin films are established will be discussed. We will also discuss how the electronic structures of thin films are impacted by the molecule’s local electrostatic environment and its interaction with the substrate, within the context of controlling interfacial energy level alignment between organic semiconductors and electrodes in electronic devices. Employing scanning tunneling microscopy and spectroscopy, experimental studies focusing on characterizing the growth and electronic structure of organic molecules on weakly interacting substrates were carried out and discussed. Studies focusing on the electronic structure of zinc phthalocyanine (ZnPc) and its fluorinated counterpart F16ZnPc were carried out on the deactivated Si(111)-B surface and h-BN/Cu(111). We show that interfacial charge transfer occurs between the deactivated Si(111)-B substrate and the F16ZnPc monolayer, which gives rise to a pronounced spatial variation of the occupied molecular state across the molecular assembly attributed to the inhomogeneous electrostatic screening of the intra-orbital Coulomb interaction in molecular adsorbates arising from the substrate boron distribution in the deactivated Si(111)-B substrate. To circumvent this inhomogeneous effect, the donor-acceptor molecular pair was studied on weakly interacting hexagonal boron nitride (h-BN)/Cu(111) which possesses a periodic electronic corrugation. We show that the formation of the lateral heterostructure drastically increases the charge transfer between F16ZnPc molecules and the substrate, which is attributed to the greater electrostatic stability of the heterostructure compared to that of the pure phase. This study highlights the importance of the substrate, even a weakly interacting one, such as h-BN/metal, can still perturb the intermolecular charge transfer and thereby the heterostructure behaviors via interfacial processes. The focus of a secondary study was to initiate preliminary experimentation towards understanding the substrate’s influence on the exotic properties of a class of organic-based systems known as charge transfer complexes (CTC). By utilizing the unique modulation properties of various weakly-interacting substrates, control of the properties of CTCs could be attained allowing for a better understanding of their fundamental physical mechanism to be developed and a new class of thin-film CTCs which will be highly relevant towards organic electronics to be developed.
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Title: The effect of growth-restriction on voluntary physical activity engagement in mice
Creator: Leszczynski, Eric
Date: 2019
Collection: Electronic Theses & Dissertations
Description: INTRODUCTION. Current evidence suggests that early life growth restriction reduces physical activity engagement. Therefore, the purpose of this investigation was to examine the effects of early life growth-restriction on levels of wheel running in mice, and determine if known biological mechanisms regulate physical activity engagement. METHODS. Using a cross-fostering, protein-restricted nutritive model, mice were growth-restricted during either gestation (GUN; N = 3 litters) or postnatal...
Show moreINTRODUCTION. Current evidence suggests that early life growth restriction reduces physical activity engagement. Therefore, the purpose of this investigation was to examine the effects of early life growth-restriction on levels of wheel running in mice, and determine if known biological mechanisms regulate physical activity engagement. METHODS. Using a cross-fostering, protein-restricted nutritive model, mice were growth-restricted during either gestation (GUN; N = 3 litters) or postnatal life (PUN; N = 3 litters), along with a well fed control group (CON; N = 3 litters). At 21 days of age, all mice pups were weaned and fed a non-restrictive healthy diet for the remainder of the study. At 45 days of age mice were individually housed in cages with free moving running wheels to assess physical activity engagement. At day 70, mice were euthanized, and the nucleus accumbens was analyzed for dopamine receptor 1 expression. Skeletal muscle fiber type and cross-sectional area of the soleus, extensor digitorom longus, and diaphragm were analyzed by immunohistochemistry. The soleus from the other hind leg was evaluated for calsequestrin 1 and annexin A6 expression. RESULTS. The PUN female mice had a reduction (P = 0.0221) in wheel revolutions per day as compared to the GUN and CON females. PUN female mice also expressed significantly higher Drd1(P = 0.0247) and Casq1 (P = 0.0398) compared to the other groups. CONCLUSION. Growth-restriction during lactation reduced physical activity in female mice by reducing the central drive to be active and displayed a more fatigable skeletal muscle phenotype.
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Title: Testing a model of healthy marriage/healthy relationships : the prediction of parenting and child well-being
Creator: Shambleau, Krista M.
Date: 2010
Collection: Electronic Theses & Dissertations
Description: Federally funded Healthy Marriage Initiative (HMI) programs provide marriage education as well as other services to low-income diverse individuals and couples at many points along the marital continuum with improving children's well-being as the overarching purpose. These programs need appropriate measures of healthy marriage for couples with children that relate to well-being. Purposes of this research were to examine the factor structure of a healthy marriage measurement developed by...
Show moreFederally funded Healthy Marriage Initiative (HMI) programs provide marriage education as well as other services to low-income diverse individuals and couples at many points along the marital continuum with improving children's well-being as the overarching purpose. These programs need appropriate measures of healthy marriage for couples with children that relate to well-being. Purposes of this research were to examine the factor structure of a healthy marriage measurement developed by Manpower Demonstration Research Corporation (MDRC) and how it varied across (a) gender, (b) race (African American and Caucasian), and (c) marital status (married and unmarried). An additional purpose was to test a measurement model, developed by Child Trends, Inc., in which healthy marriage is hypothesized to predict parenting and child well-being. This cross-sectional quantitative survey research included 343 Head Start parents (151 males and 189 females) involved in a marriage/relationship. Overall, the unidimensional healthy marriage measurement fit for both males and females and the addition of two marital virtues, namely forgiveness and teamwork, also loaded well on this measurement. The factor loadings were significant for both males and females and results of chi-square difference tests indicated that the factor loadings for the great majority of variables were invariant across gender. However, the factor loading for relationship stability (one's assessment that their relationship is not in trouble) was larger for males whereas child commitment (one's assessment of their spouse/partner's commitment to their child) was larger for females. Path analysis demonstrated that the Child Trends, Inc. healthy marriage measurement model fit differed by gender and this was supported by further SEM analysis. The effect size for the direct path between risk and healthy marriage was significantly larger for females than for males. The effect size of this path tended to be greater for African American women and unmarried women. Results using fit indices showed that the fit of the measurement model was appropriate for the diverse sample. Mediation results revealed that for both males and females, healthy marriage partially mediates the effect that depression and stress have on parenting. For females, parenting partially mediates the effect between risk and children's social competence as well as between healthy marriage/healthy relationships and children's social competence. Findings demonstrate support for the Child Trends' measurement model that healthy marriage/healthy relationships may enhance children's social competence through positive parenting. Study results may inform federal and state healthy marriage and family initiatives as well as marriage and relationship education in terms of program delivery and evaluation.
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Title: Techniques and results of applying thiourea to synthetic and grass silage media for the control of Stomoxys calcitrans Linnaeus
Creator: Weinburgh, Harry B.
Date: 1956
Collection: Electronic Theses & Dissertations

Title: A survey study of the metazoan fauna of the psammolittoral zone of Mud Lake, Barry County, Michigan
Creator: Weber, Peter Gotthilf
Date: 1963
Collection: Electronic Theses & Dissertations

Title: River valley lands in Southwestern Ontario
Creator: Weber, Edward J.
Date: 1966
Collection: Electronic Theses & Dissertations

Title: A study of the development and awareness of the need for creative uses of leisure time of high school students in a working class community
Creator: Welch, Gordon R.
Date: 1967
Collection: Electronic Theses & Dissertations

Title: The regiments : cultural histories of Zulu masculinities and gender formation in South Africa, 1816-2018
Creator: Timbs, Elizabeth H.
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "This dissertation reconstructs aspects of the history of Zulu martial heritage through the prism of the amabutho (regiments, age-grades) in KwaZulu-Natal, South Africa, from the era of Shaka Zulu (ca. 1816) to the present. Based on archival research and oral history interviews, this study argues that despite being outlawed by the British colonial regime in 1879, Zulu chiefs continued to form amabutho, but for different purposes. Regiments became youth structures for commercial labor...
Show more"This dissertation reconstructs aspects of the history of Zulu martial heritage through the prism of the amabutho (regiments, age-grades) in KwaZulu-Natal, South Africa, from the era of Shaka Zulu (ca. 1816) to the present. Based on archival research and oral history interviews, this study argues that despite being outlawed by the British colonial regime in 1879, Zulu chiefs continued to form amabutho, but for different purposes. Regiments became youth structures for commercial labor recruitment and British military conscription; they enabled indigenous leaders to access martial discourse and metaphors for political mobilization; expressed cultural forms of resistance to state racism; and nurtured the sustenance of Zulu identities in a changing South Africa. Exploring the amabutho's links to the Zulu monarchy also helps to shed light on the evolving role and status of the Zulu Royal House. While both the white-run Natal and Union governments feared the influence that Shaka's successors held among Zulu-speaking Africans, the authorities also relied on Paramount Chief Solomon to recruit black volunteers from Natal and Zululand for World War I. In the apartheid era (1948-1994), the invocation of the Zulu nation's warrior legacy endured. As migrant laborers, Zulu men recreated their martial identities and manifestations of the amabutho became more abstract, emerging in society, culture, and politics in unexpected ways. As the struggle against apartheid intensified, the continued relevance of this martial heritage mobilized Zulu communities, bringing them in conflict with first the African National Congress and later the United Democratic Front. In the post-apartheid period (1994-present), the rhetoric, symbolism, and practices of Zulu regiments continues to resonate and evolve. In the case of "high politics," Zulu political leaders turn to martial metaphors to engender support, while, on the ground, local authorities throughout the province struggle to maintain the traditions that give these metaphors meaning. The historiographical significance of this dissertation is threefold. First, it extends earlier studies to consider Zulu martial masculinity over two centuries. Second, it uncovers how amabutho shaped, and have been shaped by, white anxieties about Zulu men's "violent potential" as well as a need for cheap labor. Third, this dissertation reconsiders the shifting role of chiefs and kings in South Africa since 1800."--Pages ii-iii.
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Title: The initial phase of pathogenesis in Victoria blight of oats
Creator: Yoder, Olen C.
Date: 1968
Collection: Electronic Theses & Dissertations

Title: Friction equivalents of take-offs in rectangular ducts
Creator: Yohn, James Harold
Date: 1950
Collection: Electronic Theses & Dissertations

Title: The effect of chain extender on the molecular weight and hydrolytic degradation of poly(lactic acid)
Creator: Limsukon, Wanwarang
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "The effect of chain extender (Cex) on the molecular weight properties and hydrolytic degradation of modified PLA films (PLA--Cex) was determined and compared with PLA without Cex (PLA--Con). Effects of the Cex content and the residence time on the molecular weight were reviewed using melt blending and compression molding. A response surface methodology was applied to design the experiments and estimate the optimal conditions for obtaining the maximum weight average and number average...
Show more"The effect of chain extender (Cex) on the molecular weight properties and hydrolytic degradation of modified PLA films (PLA--Cex) was determined and compared with PLA without Cex (PLA--Con). Effects of the Cex content and the residence time on the molecular weight were reviewed using melt blending and compression molding. A response surface methodology was applied to design the experiments and estimate the optimal conditions for obtaining the maximum weight average and number average molecular weight achieved at 1.5 wt% Cex and residence time of 17 minutes. The hydrolytic degradation experiments were run in water from 40 to 95 °C and in 50% ethanol from 40 to 85 °C. The rate of hydrolytic degradation of PLA--Cex film was estimated using mathematical models, and it was considerably lower than that of PLA--Con in all conditions. The activation energy for hydrolysis above Tg was determined using the Arrhenius equation, showing no significant difference between PLA--Cex and PLA--Con. The Vogel-Tammann-Fulcher (VTF) and the Williams-Landel-Ferry (WLF) models were used for studying the hydrolytic degradation of polymers over a broad range of temperature crossing Tg. A master curve was constructed using the time-temperature superposition principle. The experimental data at 85 °C were used to predict the degradation behavior at 40 °C. It was found that PLA--Cex would take approximately 72 percent more time than PLA--Con to degrade to soluble oligomer chains."--Page ii.
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Title: Therapeutically targeting autophagy in non-small cell lung cancer
Creator: Yco, Lisette Pangilinan
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Autophagy is a conserved catabolic pathway which sequesters intracellular components in lysosomes to recycle macromolecules for cell maintenance. The role of autophagy in tumor cells is dynamic and depends on many factors including tumor types, tumor stages, and activity of several tumor suppressors and oncogenes. In this thesis, I wanted to improve our understanding of the unique relationship of autophagy with tumor suppressor p53 and oncogenic KRAS in cancer cells, particularly in NSCLC....
Show moreAutophagy is a conserved catabolic pathway which sequesters intracellular components in lysosomes to recycle macromolecules for cell maintenance. The role of autophagy in tumor cells is dynamic and depends on many factors including tumor types, tumor stages, and activity of several tumor suppressors and oncogenes. In this thesis, I wanted to improve our understanding of the unique relationship of autophagy with tumor suppressor p53 and oncogenic KRAS in cancer cells, particularly in NSCLC. First, I demonstrated that stabilized nuclear wild-type p53 through HDM2 inhibition with MK-8242 or nutlin-3a could induce autophagy in tumor cells through transactivation of several autophagy-related genes (DRAM, FOXO3A, SESN2, and MRCKα) and autophagy core genes (ATG4A and ULK1). In addition, I found that inhibiting of KRAS G12C signaling and suppressing mTORC1 activity by selective KRAS G12C inhibitor, ARS-853, could drive autophagy response in KRAS G12C NSCLC cell lines. Since autophagy could also promote survival under stress induced by several anticancer agents, I designed a combination study using newly reported selective ULK1 inhibitor, ULK-101, with ARS-853 in KRAS mutant NSCLC. Autophagy inhibition with ULK-101 dramatically enhanced the ability of selective KRAS G12C inhibitor to impair the viability of KRAS G12C NSCLC. Together, my study provided evidence that autophagy serves as a survival pathway in tumor cells and that future assessment of small molecule that target autophagy core proteins may be potential cancer therapeutic option in p53 wild-type and KRAS G12C NSCLC.
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Title: Essays in the economics of education
Creator: Lee, Hwanoong
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "This dissertation comprises three essays on the Economics of Education. Its ultimate focus is to understand how different agents in the education market respond to releasing information about teacher and school performance and how public interventions influence human capital accumulation. The first essay "The Effect of Releasing Teacher Performance Information to Schools: Teachers' Response and Student Achievement" examines the effects of releasing teacher value-added (VA) information on...
Show more"This dissertation comprises three essays on the Economics of Education. Its ultimate focus is to understand how different agents in the education market respond to releasing information about teacher and school performance and how public interventions influence human capital accumulation. The first essay "The Effect of Releasing Teacher Performance Information to Schools: Teachers' Response and Student Achievement" examines the effects of releasing teacher value-added (VA) information on student performance in two settings; in the first, VA data was released to all potential employers within the district, while in the second, only the current employer received the data. I find that student achievement increased only in the district where the VA scores were provided to all potential employers. These effects were driven solely by improved performance among ex-ante less-effective teachers; the null effects in the other setting, however, were driven by moderate declines in performance among ex-ante highly-effective teachers and small improvements among less-effective teachers. These results highlight the importance of understanding how the design features of VA disclosure translate into the productivity of teachers. The second essay "The Role of Credible Threats and School Competition within School Accountability Systems: Evidence from Focus Schools in Michigan" studies the impact of receiving accountability labels on the student achievement distribution under No Child Left Behind (NCLB) waivers. Using a sharp regression discontinuity (RD) design, I examine the achievement effects of Focus (schools with the largest achievement gaps) labels and find that schools receiving the Focus label improved the performance of low-achieving students relative to their barely non-Focus counterparts, and they did so without hurting high-achieving students. The positive achievement effects for Focus schools were entirely driven by Title 1 Focus schools that faced financial sanctions associated with being labeled the following year. There is no evidence of an achievement effect associated with the Priority label. Next, I examine heterogeneous effects by looking at the number of alternative nearby schooling options. I find that when schools are exposed to a competitive choice environment, receiving the Focus label increased math test scores across the scoring distribution, while schools located in an uncompetitive choice environment improved the test scores of low achievers only. This evidence may suggest the importance of incorporating credible sanctions and school choice options into the school accountability system to maximize the effectiveness of the system on student achievement. Finally, the third essay "The Effects of School Accountability Systems Under NCLB Waiver: Evidence from Priority Schools in Michigan" investigates the impact of receiving Priority labels on the student achievement distribution under No Child Left Behind (NCLB) waivers. Using a sharp regression discontinuity (RD) design, I examine the achievement effects of the Priority (schools with the lowest performance) label and find no evidence of an achievement effect associated with the Priority label. Next, I examine whether assigning the Priority label induced the changes in the composition of students. I define several key measures of student composition and find no evidence that the Priority designation influenced the student composition of schools."--Pages ii-iii.
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Title: Guidelines to religious station management : a descriptive analysis of the objectives, and practices of station DYSR, Dumaguete City, Philippines
Creator: Songco, Ernesto Isip
Date: 1966
Collection: Electronic Theses & Dissertations

Title: Reaction-based modeling and control of an electrically boosted diesel engine
Creator: Men, Yifan
Date: 2019
Collection: Electronic Theses & Dissertations
Description: This dissertation presents the reaction-based modeling of diesel combustion and model-based control of diesel engine air path.The dissertation first presents a control-oriented reaction-based diesel combustion model that predicts the time-based rate of combustion, in-cylinder gas temperature and pressure over one engine cycle. The model, based on the assumption of a homogeneous thermodynamic combustion process, utilizes a two-step chemical reaction mechanism that consists of six species:...
Show moreThis dissertation presents the reaction-based modeling of diesel combustion and model-based control of diesel engine air path.The dissertation first presents a control-oriented reaction-based diesel combustion model that predicts the time-based rate of combustion, in-cylinder gas temperature and pressure over one engine cycle. The model, based on the assumption of a homogeneous thermodynamic combustion process, utilizes a two-step chemical reaction mechanism that consists of six species: diesel fuel (C10.8H18.7), oxygen (O2), carbon dioxide (CO2), water (H2O), nitrogen (N2), and carbon monoxide (CO). The temperature variation rate is calculated based on the rate of change of species concentrations, and the heat loss correlation is also used to study the model performance. The accuracy of the model is evaluated using the test data from a production GM 6.6 L, 8-cylinder, turbocharged engine. The model is calibrated over large engine speed and load range as well as different injection timings and exhaust gas recirculation (EGR) rates by solving the optimization problem. The calibrated reaction-based model accurately predicts the indicated mean effective pressure, while keeping the errors of in-cylinder pressure and temperature small, and at the same time, significantly reduces the calibration effort, especially when the engine is operated under multiple fuel injection operations, comparing to Wiebe-based combustion models. The calibrated model parameters have a strong correlation to engine speed, load and injection timings, and as a result, a universal parameter calibration structure is proposed for entire operational conditions.The second part of the dissertation is to obtain a parametric understanding of diesel combustion by developing a physics-based model that is able to predict the combustion metrics, such as in-cylinder pressure, burn rate, and indicated mean effective pressure (IMEP) accurately, over a wide range of operating conditions, especially with multiple injections. In the proposed model, it is assumed that the engine cylinder is divided into three zones: a fuel zone, a reaction zone, and an unmixed zone. The formulation of reaction and unmixed zones is based on the reaction-based modeling methodology, where the interaction between them is governed by Fick's law of diffusion. The fuel zone is formulated as a virtual zone, which only accounts for mass and heat transfer associated with fuel injection and evaporation. The model is validated using test data under different speed and load conditions, with multiple fuel injections and EGR. It is shown that the three-zone model outperformed the single-zone model in in-cylinder pressure prediction and calibration effort with a mild penalty in computational time. One set of calibration parameters are used for all engine operating conditions.The third part of the dissertation is modeling and control of engine air path with an electrically assisted boosting system. A physics-based control-oriented engine air path model with electrical assistance has been developed. The model is validated with steady-state engine test data and standard driving cycle data. Through one-dimensional simulation, it is found that the electrically assisted boosting system is able to improve engine performance under both steady-state and transient conditions. A model-based controller has been developed for the electric booster (eBoost) and bypass valve to improve the transient performance of engine load response. Experiments have been performed on a Ford 6.7 L, 8-cylinder, turbocharged diesel engine equipped with a prototype eBoost and a standard EGR valve as the bypass valve. Steady-state test results have shown that eBoost is capable of improving engine efficiency by reducing pumping loss, due to reduced turbine speed when eBoost is providing additional boost energy. In the transient process, eBoost is able to significantly reduce the response time of boost pressure tracking, as validated by load step tests.
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Title: Associations of four PROMIS self-efficacy for managing chronic conditions measures and the patient activation measure (PAM) among acute stroke survivors : an analysis of the Michigan Stroke Transitions Trial (MISTT) data
Creator: Fritz, Michele Christine
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "BACKGROUND: Successful stroke transitions rely on effective self-management abilities to address stroke deficits and to prevent recurrent stroke. Patient activation and self-efficacy (confidence) are two behavioral constructs that influence successful self-management and are associated with healthier lifestyles and better health outcomes. OBJECTIVE: This cross-sectional, secondary analysis of the Michigan Stroke Transitions Trial aimed to determine the associations between 4 PROMIS self...
Show more"BACKGROUND: Successful stroke transitions rely on effective self-management abilities to address stroke deficits and to prevent recurrent stroke. Patient activation and self-efficacy (confidence) are two behavioral constructs that influence successful self-management and are associated with healthier lifestyles and better health outcomes. OBJECTIVE: This cross-sectional, secondary analysis of the Michigan Stroke Transitions Trial aimed to determine the associations between 4 PROMIS self-efficacy (SE) measures [managing medications and treatment, activities of daily living, emotions, and social interactions] and the Patient Activation Measure (PAM). METHODS: Self-reported outcomes were collected 7-days after returning home. PAM measures skill, knowledge, and confidence to manage health and healthcare, while PROMIS SE measures confidence across 4 unique domains. Independent associations of patient characteristics with each PROMIS SE and PAM were determined using a staged multivariable regression model-building approach. Finally, multivariable regression between each PROMIS SE and PAM were explored along with confounding and interaction effects. Variables significantly associated with both SE and PAM were considered as confounders and moderators. Age and education were forced into all models. RESULTS: For 180 patients mean PAM scores were 64.5 (SD: 16) and SE T-scores were near the standard mean of 50 except for SE for managing daily activities (43.5, SD: 7.5). PAM was positively correlated with each SE measure (r=0.28 to r=0.46). Only perceived emotional support and post-stroke disability were associated with both PAM and SE. Emotional support attenuated the association between all SE domains and PAM, whereas post-stroke disability only affected SE for managing daily activities. After adjusting for potential confounders, SE for managing daily activities was no longer associated with PAM. No significant interactions were found. CONCLUSIONS: During acute stroke recovery, PROMIS SE and PAM are associated. It is important to account for perceived support and disability. Longitudinal MISTT analyses will explore mediation effects to help inform causal associations between demographic, clinical, and psychosocial factors, intervention effects, and outcomes."--Page ii.
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