bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast, inexpensive, high-yielding, site-selective, chemical synthesis of cross-linked DNA duplexes via hydrazone formation between N[superscript 4]-aminocytidine and Ap-sites
Authors:   , Gamboa Varela Jacqueline
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] DNA is the central molecule of biology as it stores the genetic information for cells to properly function and develop. Modifications to the DNA can stall cellular processes such as replication and transcription, leading the cell to recruit repair machinery or in some cases undergo apoptosis. Interstrand cross-links are particularly significant types of DNA damage because they prevent strand separation required for replication and transcription. Cross-links involve bonding between the two strands of DNA. The rate and mechanism of cross-link repair in cells are not well understood. A significant challenge in the study of cross-link repair is the synthesis of chemically well-defined DNA cross-links. Here we summarize the preparation of cross-links derived from the hydrazone formation between a non-natural nucleobase N4-aminocytidine and abasic sites in duplex DNA. The cross-link was generated rapidly and in high yield. The cross-link is stable under physiological conditions but, interestingly, can be reversibly dissociated and re-formed by thermal cycling between 20-80 [degrees]C. We provided evidence that the cross-link is stable against multiple agents and the cross-link is reversible. We used this chemistry to prepare structurally diverse cross-links for the utilization in cross-link repair studies. Overall, we developed a synthetic cross-link that is easily and rapidly prepared from commercially available reagents in high yields, at defined locations in duplexed DNA.
Investigation of novel therapeutic strategies for attenuating corneal fibrosis
Authors:   , Fink Michael Kurt
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Corneal fibrosis (scarring) is a significant cause of vision loss worldwide resulting from an exuberant wound healing response driven in part by the actions of transforming growth factor beta (TGF[beta]). Non-surgical interventions allowing for the safe and complete clinical resolution of corneal fibrosis are currently lacking in physician and veterinary ophthalmology. In order to address this significant clinical need, the research presented within this dissertation is focused on developing novel pharmacologic and gene therapies to mitigate corneal fibrosis in humans and companion animal species. This dissertation sought to evaluate the safety and efficacy of two unique pharmacologic agents (Pirfenidone and Fasudil) with known antifibrotic effects in non-ocular organ systems for attenuating TGF[beta]-mediated corneal fibrosis in vitro and in vivo. We also evaluated the ability of nanoparticle-mediated combination gene therapy (PEI-GNP) with bone morphogenetic protein 7 (BMP7) and hepatocyte growth factor (HGF) to mitigate severe corneal fibrosis in vivo following corneal alkali injury. The results of these studies demonstrated the potential clinical utility of both Pirfenidone and Fasudil (HA1077) to mitigate mild to moderate corneal fibrosis as sole antifibrotic pharmacologic agents and for combination gene therapy with BMP7+HGF to resolve moderate to severe corneal fibrosis with a single topical application of hybrid nanoparticles following corneal injury. Additional in vivo analyses are needed to evaluate potential long-term local and systemic effects owing to treatment(s) and to optimize dose and dosing regimen in a species-specific manner. Each of these therapeutic strategies holds great promise for attenuating corneal fibrosis in human and veterinary patients in clinical settings
On the Euler characteristics of certain moduli spaces of 1-dimensional subschemes
Authors:   , Alhwaimel Mazen M.
Published: April 2021

Generalizing the ideas in [LQ] and using virtual Hodge polynomials as well as torus actions, we compute the Euler characteristics of some moduli spaces of 1-dimensional closed subschemes when the ambient smooth projective variety admits a Zariskilocally trivial fibration to a codimension-1 base. As a consequence, we partially verify a conjecture of W.-P. Li and Qin [LQ]. We also calculate the generating function for the number of certain punctual 3-dimensional partitions, which is used to compute the above Euler characteristics.
Seismic attenuation of regional phases in the northern Middle East and eastern Tibetan plateau
Authors:   , Ku Wenfei
Published: April 2021

Temperature and composition are two major causes for subsurface seismic anomalies. Positive temperature anomalies will lead to a reduction in both attenuation and velocity; however, compositional anomalies should not necessarily produce a strong correlation in attenuation and velocity. As a result, by combining velocity and attenuation structure we can distinguish between compositional and temperature anomalies. Using efficiency tomography and Q tomography, I have constructed Sn attenuation models for two continental-continental collision zones, the northern Middle East and the eastern Tibetan Plateau. The Tibetan Plateau was formed by the continental collision between Indian and Eurasian plates that has been going on at least since [about]50Ma. Two tomographic techniques have been used to determine the attenuation structure of the uppermost mantle beneath the eastern Tibetan Plateau. I observe lateral heterogeneity of Sn attenuation beneath the southern Tibetan Plateau that indicates a complex geometry of the underthrusting Indian continental lithosphere (UICL). Sn is blocked with relative low Q values across the Qiangtang block and Songpan-Ganzi block indicating a hot and weak lithosphere. This observation can be caused by mantle upwellings induced by the sinking slab detached from the UICL. The Turkish-Iranian plateau and Zagros, the main tectonic feature of the northern Middle East, was formed as a result of the continental collision between the Arabian and Eurasian plates since Early Cenozoic (23-35Ma). I have collected a large Sn waveform data set in the northern Middle East that I have quality controlled using both automated and manual approaches. Two tomographic techniques have been used to determine the attenuation structure of the uppermost mantle. I observe inefficient/blocked Sn and low Q values in the Turkish-Iranian plateau indicating a hot and thin mantle lithosphere. Intrinsic attenuation is the dominant uppermost mantle shear wave attenuation mechanism beneath the eastern Anatolian plateau and Lesser Caucasus. Partial melting appears to be the main cause of high attenuation in two of the regions. Scattering attenuation appears to be the dominant mechanism in the Zagros. The high attenuation in the Iranian plateau is likely not caused by partial melting thus the seismic anomalies in the uppermost mantle are likely compositional. Data censorship is a common problem in seismic attenuation studies. Discarding blocked Sn paths will cause left censored data problem and the resulting model will be biased to high Q values. Using Level of Detection Divided by Two (LOD/2) technique, I am able to obtain lower Q values and smoother variations in the resulting models comparing with censored models.
Development of fluorescent sensors for the detection of hydrophobic amines and glycolipids
Authors:   , Littlefield Charles W. Jr.
Published: April 2021

A novel fluorescent sensor was designed and synthesized to detect hydrophobic amines and was used to extract them from synthetically prepared vesicles. This sensor had a higher affinity for diamines than primary amines, providing a fluorescence decrease upon binding both analytes. This sensor bound longer chain amines such as decylamine and 1,10-diaminodecane, better than shorter chain amines such as octylamine. This binding is influenced by both hydrophobic effects and electrostatic interactions between the sensor and analyte, driven by the hydrophobic cavity on the sensor. The sensor also unexpectedly binds to spermine and spermidine, however, with an increase in fluorescence. The mechanism for this phenomenon is not yet understood. The sensor showed it is possible to remove hydrophobic amines from synthetic veiscles, which can be applied to biological systems. A fluorescent sensor for glycolipids was also attempted to be synthesized by several different methods, incurring a new synthesis through redesigning the synthesis. Each method provided undesired products, decomposition, or no reactivity. Initial redesigns were due to complications in solubility of the carbazole aldehyde. Elongating the ester chain enhanced the solubility, but it remained unreactive towards any of the attempted reactions. This redesigned the sensor with a protected acid group that has been tested towards amide bond formation reactions to install the boronic acid or a haloarene, which will then undergo a Miyaura Borylation to install the boronic acid. If this does not prove successful, it will require alternative synthetic methods to install the boronic acid.
Advancing single molecule fluorescence microscopy through the study of dynamic macromolecules
Authors:   , Menke Drew Edwin
Published: April 2021

We took a two pronged approach to our investigation of protein synthesis by the ribosome: 1) the generation of a novel fluorescence enhancing substrates 2) the development of a method for the generation of fluorescent ribosome constructs. The development and application of fluorescence based diagnostics platforms for the detection of diseases represents a promising field of research. In collaboration with another lab, we established a method for the generation of a fluorescence enhancing substrate that does not require the use of expensive imaging equipment. During further testing of the fluorescence enhancing substrate with biologically relevant samples, our method proved promising for addition applications. Understanding how and why the ribosome synthesizes protein is important to all living organisms. One known challenge for the study of the ribosome has been the generation of complex samples. We developed a process for the generation of ribosomes that is quicker, easier, and cheaper than existing methods. We then applied our methods for the generation of ribosome constructs to investigate how the ribosome, the molecule responsible for protein synthesis, is coordinated during protein synthesis. Our experiments determined that specific interactions play different roles throughout protein synthesis.
How teachers adapt to curricular and structural change : a multi-case study of three middle school language arts teachers
Authors:   , Wightman Stephanie
Published: April 2021

This study examined the experiences of three middle school language arts teachers during a time in their teaching careers where their school district underwent structural and curricular changes. During the restructuring of the grade configuration, curriculum, course assignments, teachers, teams, start time, and schedules, teachers at Smiley Middle School teachers experienced a radical change. Through interviews, blogs, professional learning team observations, and field notes, this qualitative case study examines the experiences of three language arts teachers one and a half years after the transition. The findings indicated that these teachers were largely impacted by the transition. They relied on their teacher identity to ground their day-to-day classroom changes. Their agency was disrupted, but the teachers were able to rely on professional learning teams and units of instruction to help them build back their agency. Finally, resilience was a large factor in helping the three teachers power through the changes. This study has lasting implications for building leaders, teachers, and pre-service teacher. Understanding and building up identity, agency, and resiliency among teacher may play a role in helping teachers negotiate complex changes in their school structure.
Models of gestational diabetes and offspring outcomes in mice
Authors:   , Talton Omonseigho Owomare
Published: April 2021

Gestational diabetes mellitus (GDM) is the most common pregnancy disorder. GDM pregnancies result in offspring that are more likely to develop metabolic syndrome in adolescence than the background population. As offspring experience these adverse effects during their reproductive years, GDM has the potential to propagate disease for many generations. Hyperleptinemia, a key characteristic of both GDM and maternal obesity has not been studied in isolation to determine its role in programming offspring outcomes. Hyperglycemia in the absence of obesity has also not been widely modeled without surgical or chemical means. My research goal was to study the offspring outcomes of these two facets of GDM in C57B6 mice. We observed that maternal hyperleptinemia improved offspring insulin sensitivity, and protected the offspring from developing glucose intolerance. These outcomes were partly mediated by reduced fatty acid accumulation in the liver. Our findings suggest that maternal hyperleptinemia is protective of offspring glucose control. Maternal hyperglycemia in lean dams increased offspring adiposity while glucose tolerance was unchanged. This effect was mediated by a preference for glucose over lipids for substrate utilization, and multiple gene expression changes in the male adipose tissue and liver. Our results indicate that lean maternal hyperglycemia results in metabolically healthy obesity in offspring. This work demonstrates that GDM in lean women may not negatively affect glucose tolerance, and that maternal hyperleptinemia may mediate this, through improving insulin sensitivity. It supports other data that suggest that the liver and adipose tissue are key regulators of whole body metabolism.
Art/making sense of policy in art education
Authors:   , Livek Michelle
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This manuscript style dissertation creates a continually expanding vista of policy at play in art/education. The scope of this manuscript style dissertation through the micro, mezzo, and macro levels of social interaction. It begins, with my work of as a secondary artist/teacher and how I creatively forged new territory for "data" and accountability within my practice and what that produce/d/s in me and my students (micro). As I developed this new method of data collection (the one-page portfolio), I became curious about how other artist/teachers have done the same within the paradoxical nature of being both a policy target and actor (micro >> mezzo). My second article is positioned within a peer group of artist/teachers spending time thinking about their policy enactments (mezzo) as visual bricolages. The research participation created the opportunity to celebrate that which they already do and to accept that their policy enactments are valuable to themselves, their students, and the field of art education at large (mezzo >> macro). I became compelled to interleave my identity as a social practice art influence with my desire to open this cathartic action of celebrating their personally relevant, and creative policy navigations, to all artist/teachers (macro). The third article manifests as social practice Participatory Dialogic Policy Enactment Analysis as Social Practice.
"Shots reported on campus" : an experimental study of crisis communication and emergency message design and dissemination
Authors:   , Sorenson Mary E.
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The purpose of this study is to test emergency messages that are communicated to campus communities during a human-caused crisis event. Research shows that campus communities are experiencing human-caused crises such as active shootings but are not well-equipped to handle such crises. This study uses experimental methods to test various emergency messages within two mediated contexts: official university email and university Facebook. This study tested the effects of emergency messages on three key outcome variables of interest: perceptions of message effectiveness, perceptions of organizational credibility, and individual emotional reaction. Results from the current study provide evidence that including detailed information (about the location of the event and/or actions to take) increases perceptions of organizational credibility and decreases feelings of anger, disgust, and contempt. Furthermore, evidence suggests that the aforementioned emotions mediate the relationship between message exposure and perceptions of message effectiveness. Specifically, when such feelings are decreased then perceptions of message effectiveness increases. Findings from this study contribute to a foundation of research dedicated to college campus crises. Furthermore, results from this study provide practical suggestions for crisis management teams that will positively influence cultures of preparedness and effective emergency communication.
On hydrodynamic equations and their relation to kinetic theory and statistical mechanics
Authors:   , Xue Jianfei
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] We establish conditions on the Hamiltonian evolution of interacting molecules that imply hydrodynamic equations at the limit of infinitely many molecules and show that these conditions are satisfied whenever the solutions of the classical equations for N interacting molecules obey uniform in N bounds. We show that this holds when the initial conditions are bounded and the molecule interaction is weak enough at the initial time. We then obtain hydrodynamic equations that coincide with Maxwell's. We then construct explicit examples of spontaneous energy generation and nonuniqueness for the standard compressible Euler system, with and without pressure, agagin by taking limits of Hamiltonian dynamics as the number of molecules increases to infinity. The examples come from rescaling of well-posed, deterministic systems of molecules that either collide elastically or interact via singular pair potentials. We also obtain Percus macroscopic equation as the limit of a sequence of single systems of N hard rods with the number of hard rods going to infinity. Finally, we establish the strict convexity of the pressure as a thermodynamic limit for continuous systems. As a result we show the existence of a local bijection between macroscopic density, velocity, and energy on one hand and thermodynamic parameters on the other, for continuous systems.
Comparative analysis of the role of cytokinin in feeding site formation induced by cyst and root-knot nematodes
Authors:   , De La Torre Cuba Carola M.
Published: April 2021

Cyst and root-knot nematodes are obligate plant parasites of global economic importance with a remarkable ability to reprogram root cells into unique feeding sites. Previous studies have suggested a role for cytokinin in feeding site formation induced by these two types of nematodes, but the mechanistic details have not yet been described. Using Arabidopsis as a host plant species, this study shows a comparative analysis of cytokinin genes in response to the beet cyst nematode (BCN), Heterodera schachtii, and the root-knot nematode (RKN), Meloidogyne incognita. Distinct differences in the regulation of cytokinin biosynthesis, catabolism and signaling genes in response to BCN and RKN infection were found, suggesting differential manipulation of the cytokinin pathway by these two nematode species. Furthermore, key cytokinin genes contributing to BCN and RKN disease susceptibility were identified. This study also evaluated ARABIDOPSIS HISTIDINE KINASE (AHK), ahk2/3, ahk2/4 and ahk3/4 receptor mutant lines in response to BCN and RKN infection and found a decrease in susceptibility compared to the wild type control, Col-0. An analysis of ahk double mutants using CYCB1:GUS/ahk introgressed lines revealed contrasting differences in the cytokinin receptors controlling cell cycle activation in feeding sites caused by RKN and BCN. Results from these studies could be used in the future to engineer novel forms of nematode resistance in crops of economic importance.
Examination of nucleus accumbens mechanisms underlying the motivation for physical activity
Authors:   , Ruegsegger Gregory Neal
Published: April 2021

Physical inactivity, a primary contributor to numerous diseases including obesity, type 2 diabetes, depression, and dementia, has reached pandemic levels worldwide. Alarmingly, the percentage of individuals engaging in physical activity is low and decreasing. Accelerometry data shows that > 90% of adults fail to meet the U.S. Physical Activity Guidelines despite the excess of knowledge suggesting exercise improves health. Therefore, beginning to understand the molecular mechanisms which influence physical activity levels is imperative for the development of therapies to reduce sedentary behavior. The work presented in this dissertation made use of three independent experimental paradigms in rats to test the hypothesis that differences in the mesolimbic dopamine system associate with/cause changes in voluntary physical activity. In the first study, rats selectively bred for high (HVR) or low (LVR) voluntary wheel running distance were used to assess inherent differences in opioidergic signaling between HVR and LVR, as well as the influence of dopamine on opioid-induced changes in voluntary wheel running. Mu-opioid receptor expression and function was increased in the nucleus accumbens (NAc) of HVR compared to LVR. Likewise, naltrexone injection decreased dopamine-related mRNA expression in mesolimbic brain regions and reduced wheel running in HVR, but not LVR. Finally, lesion of dopaminergic neurons in the NAc prevented the decrease in running following naltrexone administration in HVR, suggesting opioidergic signaling requires downstream dopaminergic activity to influence voluntary running. In the second study, the transgenerational effect of maternal Western diet (WD) on offspring voluntary wheel running was assessed. Wheel running was increased in female WD offspring from 4-7 weeks of age, but decreased running from 16-19 weeks of age, compared to offspring from chow fed dams. These age-specific changes in wheel running are associated with the up- and down-regulation of dopamine receptor 1 in the NAc at 6 and 18 weeks of age, respectively, in WD female offspring, which in turn was negatively associated with leptin receptor mRNA in the ventral tegmental area. In the third study, age-related influences on wheel running were assessed in 8 and 14 week-old rats. In addition to a [about]60% reduction in running, RNA-sequencing revealed down-regulations in networks related to cAMP-mediated signaling and synaptic plasticity in the NAc from 8 to 14 weeks-old. The down-regulations of these networks was mirrored by reductions in dendritic spine density in the NAc from 8 to 14 weeks-old. Additionally, intra-NAc injection of the Cdk5 inhibitor roscovitine, a known modulator of dendritic density and dopamine signaling, dose-dependently decreased wheel running. Despite the varying experimental models used in this dissertation, these findings collectively suggest that alterations in dopaminergic signaling in the NAc associate with, and influence, voluntary physical activity.
Sequences of rank-1 projections and Gabor tight fusion frames
Authors:   , Tuomanen Brian
Published: April 2021

This dissertation provides new results in two areas. The first part concerns the particular properties that are inherited by a sequence of rank-1 projections from the inducing sequence of unit-norm vectors. The second part applies ideas from Gabor analysis for a non-trivial construction of so-called Tight Fusion Frames. The particular necessary conditions such that these Gabor Tight Fusion Frames may perform signal retrieval modulo phase are then investigated.
Negro education
Authors:   , Miller Barney Elic
Published: April 2021

"This study is divided into three parts. Part I attempts to review the general principles involved in education for modern efficiency for whites, for the purpose of throwing some light upon the problems involved in educating the negro for his share in our American life. Part II presents the .conclusions of recent writers upon two topics: (1) Are the mental differences between the two races such that the same general principles of education cannot be applied? (2) What have Negro leaders, and other close students, held essential in the education of Negro boys and girls? Part III deals with the results obtained from a survey of three Negro schools of Missouri. The data upon which this study is based, gathered from the students of the three Negro schools, throw light upon the general problem of Negro education as it relates itself to the home-life and individual interests of the students."--Page 2.
Effects of health information seeking behaviors on anxiety, and loss among East Asian international students
Authors:   , Chuang Chih-Chun
Published: April 2021

This study examined the influences of anxiety, health information seeking behavior, cross-cultural loss on satisfaction with life among 186 East Asian international students while studying abroad in the U.S. The results showed that general and health anxiety are both significantly associated with satisfaction with life, while there is a positive association between health anxiety and Internet health information seeking behaviors. Internet health information seeking behavior also mediated the link between health anxiety and satisfaction with life in the U.S. Cross-cultural loss did not moderate the relationship between Internet health information seeking behavior and satisfaction with life as predicted. Results of this study provide additional knowledge about East Asian international students' health, including the connection between general and health anxiety, Internet health information seeking behavior, and satisfaction with life. Findings from this study may have implications for higher education institutions serving international students.
A nation-branding perspective on Euro-Atlantic integration and online representation of a nation - the case of the country of Georgia
Authors:   , Topouria Giorgi
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Using a theoretical framework integrating the theory of Competitive Identity (Anholt 2007), Conceptual Framework of the Formation of a Nation's Image (Dinnie 2008) and Conceptual Model of Key Perspectives for Analysis of a Nation's Image (Fan 2008), the dissertation analyzes the process of transition of the country of Georgia towards Euro-Atlantic integration from nation-branding (external) and public diplomacy (internal) viewpoints, with special focus and attention on the role and functions of communications in this process. The role and importance of different dimensions of Georgia's competitive Identity and various communication channels are examined in the context of Georgia's pursuit of its declared strategic goal to become a member of the North Atlantic Treaty Organization (NATO) and the European Union (EU). Analysis is conducted using exploratory qualitative case study approach based on a combination of a comprehensive review of a large amount of different texts and documents and a series of a total of 30 semi-structured in-depth interviews with representatives of key domestic and international experts and stakeholders of the Georgia's nation-brand. In the second part of the dissertation, a new concept of Online Representation of a Nation (ORN) is explicates and developed in detail and is integrated into the suggested conceptual framework as a center piece that interconnects and rearranges the components of the framework into a new, expanded and more complex model. The dissertation also develops a methodology and an instrument for measurement of the explicated concept of ORN using a combination of quantitative and qualitative content analysis of different purposive samples of online information and suggests ranking of nation-brands based on their respective ORN.
Development of phase change material integrated oriented strand board for thermal energy storage
Authors:   , Hasan Layla Muhsan
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This study is attempted to develop energy storing oriented strand board (OSB). Energy storing capability is achieved by integrating phase change material (PCM) in the wood board. The effect of thermal energy storage in the building envelope is to reduce indoor temperature fluctuations and delay air temperature maximum to off-peak demand period and it will help to reduce the energy consumption in buildings envelop. In particular, we developed thermal energy storing shape stabilized phase change materials (SSPCM) integrated oriented strand board (OSB) wood based panels. High density polyethylene was used as a supporting material to prevent the leakage of liquid PCM during phase change. Different additives were added to increase the percentage of PCM that can be used in SSPCM preparation without leakage during the phase change, to serve as flame retardant, or to enhance the bonding between the SSPCM and wood strands. Three types of flame retardants were used, purified expanded graphite (EG), graphite nanoplatelets (xGnP) and nano magnesium hydroxide. The results of this study show that the integration of SSPCM in oriented strand board lowers the heat flux as compared to OSB without SSPCM.
Strategic human capital management and public sector performance : an investigation of federal agencies
Authors:   , Wesemann Andrew
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.]
Essays on labor economics
Authors:   , Tan Li
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This dissertation consists of two chapters on labor economics. In the first chapter, we study redistributions via the United States Social Security retirement system for cohorts of men born during the second half of the 20th century. Our focus is on redistributions across race and education groups. The cohorts we study are younger than cohorts studied in previous, similar research, and thus more exposed to recent increases in earnings inequality. All else equal, this should increase the degree of progressivity of Social Security redistributions due to the structure of the benefit formula, but we find that Social Security redistributions exhibit little progressivity for individuals born as late as 1980. Differential mortality rates across race and education groups are the primary explanation. While black-white mortality gaps have narrowed some in recent years, they remain large and dull progressivity. Mortality gaps by education level are also large and unlike the race gaps are widening, which puts additional regressive pressure on Social Security redistributions. In the second chapter, I investigate the technique of imputing top-coded income data in longitudinal surveys. The incomes of top earners are typically top-coded in survey data to protect individuals' identities. Common imputation methods used to recover top-coded income values are limited in several ways when applied to longitudinal data. I show that the accuracy of imputed income values for top earners in longitudinal surveys can be improved significantly by incorporating information from multiple time periods into the imputation process in a simple way. Moreover, I introduce an innovative, nonparametric empirical Bayes imputation method that further improves imputation quality. With a sample of individuals for whom incomes are pseudo top-coded (i.e., in which the exact income figures are accessible but temporarily expunged), I show that the Bayesian imputation method reduces the root mean squared error of imputed income values by 19-46% relative to standard approaches in the literature. After documenting this improvement in performance, I illustrate the benefits of the Bayesian method for investigating multi-year income inequality.
Modeling the inertial torque imbalance and foundation forces within an inline internal combustion engine : quantifying the equivalent mass approximation
Authors:   , Ali Muslim Muhsin
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The main object of this dissertation is to study the dynamic analysis of an inline internal combustion engine. This dissertation presents the kinematics and kinetic analyses of an inline internal combustion engine crank mechanism, the dynamic torque imbalance and foundation forces for a single-piston and multi-piston engines are studied as well. The objectives of this dissertation are to explore the inertial-torque characteristics and foundation forces of an inline, internal combustion engine with connecting-rod joints that are evenly spaced about the centerline of the crankshaft, and to evaluate the goodness of a mass approximation that is customarily used in machine design textbooks. In this dissertation the number of pistons within the internal combustion engine is varied from 1 to 8. In order to generalize the results, the reaction force between the ground and the crank in the x-direction and y-direction equations are nondimensionalized and shown to depend upon only six nondimensional groups, all related to the mass and geometry properties of the connecting rod and crank while the reaction force between the connecting rod and the piston in the x-direction y-direction, reaction force between the crank and the connecting rod in the x-direction y-direction, reaction force between the piston and the cylinder wall, and the inertial-torque equations are nondimensionalized all related to the mass and geometry properties of the connecting rod. As shown in this dissertation, the largest torque imbalance is exhibited by a 2-piston engine. The next largest torque imbalance is exhibited by a 3-piston engine, followed by a single-piston engine (this is not monotonic). The largest foundation forces are exhibited by a single-piston engine. The next largest foundation forces are exhibited by a 2-piston engine, followed by a 3e-piston engine, and that a dramatic reduction in the foundation forces and torque imbalance may be obtained by using 4 or more pistons in the design, when using as many as 8 pistons the foundation forces and torque imbalance essentially vanishes. It should be observed that the mass approximation captures 100 percent of the variability of the actual torque imbalance for engines that are designed with an odd number of pistons equal to or greater than three. The mass approximation captures 100 percent of the variability of the actual reaction force between the piston and cylinder wall for engines that are designed with single-piston and multi-pistons. The mass approximation captures 100 percent of the variability of the actual reaction force against piston pin for engines that are designed with single-piston. It is also shown in this dissertation that the customary mass approximations for the connecting rod may be used to simplify the analysis for all engine designs without a significant loss of modeling accuracy.
Exploring star formation in high-mass galaxies in the low-z universe
Authors:   , Runge James
Published: April 2021

We present a quantitative analysis of high-mass, low-z galaxies in order to investigate the 'downsizing' scenario of galaxy evolution. High-mass, low-z galaxies with ongoing star formation, antithetical to the 'downsizing' model, are identified using the 22ï¿½m data (W4 band) from the Wide-field Infrared Survey Explorer (WISE). A cluster and field sample is chosen to investigate any possible environmental effects. The cluster sample is based upon the GMBCG catalog, which contains 55,424 brightest cluster galaxies (BCGs) at 0.1 [less than or about] z [less than or about] 0.55 identified in the Sloan Digital Sky Survey (SDSS). We identify 389 W4-detected BCGs (W4BCGs) that have median SFRs of [about]50 M[symbol]/yr based upon their total IR luminosity (LIR), which is attributed to dust-enshrouded star formation. BCGs with such high SFRs are found in "cool-core" clusters and the star formation is thought to be fueled by a "cooling flow." Using Chandra X-ray data, it is shown that a subset of BCGs do reside within coolcores, but their mass deposition rates cannot account for the SFR. For comparison, a field sample is drawn from the Max-Planck Institute for Astrophysics - John Hopkins University (MPA-JHU) "value-added" SDSS DR7 catalog of spectrum measurements. A set of 1,244 high-mass, elliptical field galaxies within the same redshift range as the W4BCG catalog are identified for comparison. The median mass for the field sample is lower than the W4BCGs (Log(M/M[symbol])=10.9 and 11.2 respectively), as are their SFRs. However, the specific star formation rate (sSFR), the star formation rate per stellar mass, is comparable for both groups (Log(sSFR)[about]-9.7). This possibly reveals that there is no environmental dependence on the sSFR for these W4-detected galaxies. While a possible mechanism responsible for the SFR was identified for the W4BCGs, the process responsible for the star formation in the field sample requires further investigation.
Multicriteria pathfinding in uncertain simulated environments
Authors:   , Buck Andrew R.
Published: April 2021

Multicriteria decision-making problems arise in all aspects of daily life and form the basis upon which high-level models of thought and behavior are built. These problems present various alternatives to a decision-maker, who must evaluate the trade-offs between each one and choose a course of action. In a sequential decision-making problem, each choice can influence which alternatives are available for subsequent actions, requiring the decision-maker to plan ahead in order to satisfy a set of objectives. These problems become more difficult, but more realistic, when information is restricted, either through partial observability or by approximate representations. Pathfinding in partially observable environments is one significant context in which a decision-making agent must develop a plan of action that satisfies multiple criteria. In general, the partially observable multiobjective pathfinding problem requires an agent to navigate to certain goal locations in an environment with various attributes that may be partially hidden, while minimizing a set of objective functions. To solve these types of problems, we create agent models based on the concept of a mental map that represents the agent's most recent spatial knowledge of the environment, using fuzzy numbers to represent uncertainty. We develop a simulation framework that facilitates the creation and deployment of a wide variety of environment types, problem definitions, and agent models. This computational mental map (CMM) framework is shown to be suitable for studying various types of sequential multicriteria decision-making problems, such as the shortest path problem, the traveling salesman problem, and the traveling purchaser problem in multiobjective and partially observable configurations.
Neutron scattering studies of water diffusion near the interface of model cell membranes
Authors:   , Buck Zachary
Published: April 2021

Membrane proteins represent a significant frontier in structural biology they are ubiquitous in nature and perform a variety of tasks that help govern cellular activity. Their structure, insertion mechanisms, and function largely depend on the interactions between peptide-lipid domains and the hydrating water. Therefore, the dynamics of the membrane-associated water and its interaction with embedded proteins remain some of the most fundamental issues in biological physics today. Single-supported lipid bilayers (SSLBs) provide model systems for investigating their structural and dynamical properties via atomic force microscopy (AFM) and quasielastic neutron scattering (QENS), respectively. QENS measurements on SSLBs comprised of zwitterionic (DMPC) and anionic (DMPG) lipids reveal vastly different freezing/melting behavior of their hydration water, while also elucidating various types of membrane-associated water characterized by their translational diffusion rates. Moreover, results from temperature-dependent neutron diffraction measurements on SSLBs have established a correlation between the formation of various crystalline ice structures and freezing/melting transitions observed in the elastic component of their QENS spectra, thereby confirming the various growth modes of the membrane-associated ice. We have since enhanced the complexity and biological relevance of such systems by incorporating the antimicrobial peptide, melittin, into a DMPC membrane. On monitoring the incoherent elastic neutron intensity as a function of temperature from melittin-treated DMPC membranes, we observe an abrupt freezing transition of the associated water not seen in the bare membrane case. Moreover, the change in elastic intensity of this freezing step increases in proportion to peptide concentration, suggesting that water could be freezing onto membrane-bound melittin. In addition to bulk-like water present in the sample, analysis of the quasielastic spectra collected provides evidence of a second water type that diffuses more slowly and freezes at a higher temperature than the bulk-like water. Furthermore, in situ AFM studies reveal the formation of dimple-like features on the surfaces of such membranes when melittin concentrations exceed 0.5 [mu]M. These changes induced in the bilayer have been interpreted as aggregates of membrane-bound melittin responsible for the altered freezing behavior and dynamics of the hydration water. An unexpected time dependence of the elastically-scattered neutron intensity was observed when membranes of DMPC treated with 0.5 [mu]M melittin were annealed in the temperature range 325 K less than T less than 340 K, an effect not present in DMPC membranes treated with other melittin concentrations. These results are consistent with the slowing down of hydrogen nuclei and anchoring of surface-bound melittin peptides while interacting with DMPC membranes.
Perceptions of out-of-field teachers of the sustainability of urban teacher quality support systems
Authors:   , Coleman Niketia L.
Published: April 2021

Educational reform movements set ambitious goals for student learning. Numerous factors contribute to students achieving these goals. It has been widely understood that "the increasing emphasis on quality of teaching and learning has placed new demands on staff development, and the search for models and methodologies which are promising for professional development of academic staff has become an important agenda in itself" (Ho, A.,2001 P.35). Effective changes in practice require a great deal of learning on the part of teachers and an even greater amount of support and guidance from administrators (Borko, 2004, Putnam and Borko, 2000). Problematic practices in hiring and staffing make it difficult, albeit impossible, to provide an equal distribution of qualified teachers in high poverty districts and schools serving minorities. Contributing to the problem of teacher inequality and underqualified teachers is the phenomenon of out-of-field teaching- a term in reference to certified or qualified teachers who were teaching a subject in which they had no formal qualification or training (Hobbs, 2013). These teachers often receive little training and support and therefore find it difficult to experience success. Through qualitative interviewing this study seeks to explore the perceptions of out-of-field teachers and mentors and understand how they make meaning of their experiences. Five themes emerged from the study: ineffective training and professional development, desire for success, buy in, time, and support. Teachers and mentors want professional development that is meaningful to the work they do in the classroom. Educators, especially those teaching out-of-field, need training that is intense, focused and content oriented. Buy in is vital to any professional training. Out-of-field teachers want to be included in the decision-making as to what professional development they receive. From this study, it was learned that it is a teacher's priority to make sure they are teaching content standards from day-to-day. The participants identified a lack of support as an inhibitor to that implementation. This concern for the lack of professional support among the participants bares out much of the research (Borko, 2014. Hobbs, 2015, Darling-Hammond, 2002, Ingersoll, 1999). Out-of-field teachers are highly committed to the students and communities they serve. With focused and intense training, close monitoring, time to observe skilled content area teachers, and strong support from building and district administrators, out-of-field teachers can become effective educators when teaching outside their area of expertise.
Generating sequences and semigroups of valuations on 2 dimensional normal local rings
Authors:   , Dutta Arpan
Published: April 2021

In this thesis we develop a method for constructing generating sequences for valuations dominating the ring of a two dimensional quotient singularity. Suppose that K is an algebraically closed field of characteristic zero, K[X, Y] is a polynomial ring over K and v is a rational rank 1 valuation of the field K(X, Y) which dominates K[X, Y](X,Y) . Given a finite Abelian group H acting diagonally on K[X, Y], and a generating sequence of v in K[X, Y] whose members are eigenfunctions for the action of H, we compute a generating sequence for the invariant ring K[X, Y]H. We use this to compute the semigroup SK[X,Y ]H (v) of values of elements of K[X, Y]H. We further determine when SK[X,Y ]H (v) is a finitely generated SK[X,Y ]H (v)-module.
A test of resource dependency theory using higher education institution behavioral changes after state based merit aid adoption
Authors:   , Evans Jason (Jason F.)
Published: April 2021

The purpose of this study was to analyze whether four-year, public institutions altered their behaviors as their revenue streams changed. I utilized state based merit aid adoption to examine whether institutions altered their functional expenditures and faculty employment behaviors as institutions became more resource dependent on students. The dependent variables concerning functional expenditures analyzed were instruction, research, student services, public services, academic support, institutional support, and scholarships. The dependent variables concerning faculty employment analyzed were part-time faculty, full-time non-tenure-track faculty, and fulltime tenure-track faculty. A difference-in-difference estimation strategy estimated institutional responses to a merit aid program being adopted in their state. The findings indicated that after merit aid adoption in their state, institutions altered their behaviors in ways that indicated they became more resource dependent on students. Specifically, the models indicated that, on average, institutions in states that adopted a merit aid program spent more money on instruction, institutional support, and scholarships and employed more part-time faculty than institutions in states that did not adopt any merit aid program. The findings of this study suggest that if states direct funds to students that institutions will respond as though the students provide the funding and not the state.