bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing the contextual factors' effect in social cognitive career theory among Latina/o and white women and men engineering students
Authors:   , Li Feihan
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] The current study tested a model of career persistence intentions in engineering based on Lent, Brown, and Hackett's (1994, 2000) social cognitive career theory incorporating the Realistic and Investigative themes of Holland theory (1997) among a sample of 457 college students majoring in engineering attending a Hispanic serving institution (HSI). The findings indicated that (a) proposed model with combined paths (direct and indirect effect model), which include both direct and indirect paths from contextual factors to engineering persistence intentions, fit the data for the full sample; (2) for both Realistic and Investigative models, significant paths were between Realistic/Investigative self-efficacy and Realistic/Investigative interests, engineering support and engineering persistence intentions, and engineering barriers and engineering persistence intention; (3) social cognitive career theory predictors accounted for a significant amount of variance in engineering persistence intentions (26.6% and 28.5%) for Realistic and Investigative models; (4) the model varied across women and men and across Latina/o and white engineering undergraduate students for both Realistic and Investigative models. Implications for research and practice are discussed in relation to persistence in engineering among women and Latina/o students.
The role of Pre-B-cell colony-enhancing factor in neuronal death after ischemia and motor dysfunction
Authors:   , Wang Xiaowan
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Pre-B-cell colony-enhancing factor (PBEF) is the rate-limiting enzyme in the salvage pathway of mammalian nicotinamide adenine dinucleotide (NAD+) biosynthesis via converting nicotinamide (NAM) to nicotinamide mononucleotide (NMN). NAD+ is a molecule playing a pivotal role in the cellular metabolisms and energy production. Moreover, increasingly important roles of PBEF-NAD+ cascade have been reported in diverse neurodegenerative diseases including ischemic stroke, axon degeneration and motor neuron disorders. However, currently, the mechanisms downstream of PBEF are not completely understood. In Chapter one, I reviewed the biological functions of PBEF, the pathology of cerebral ischemia, the potential molecular mechanisms of PBEF mediated neuronal protection during ischemic stroke and motor dysfunctions. Then, in Chapter two and Chapter three, I investigated the role and molecular mechanisms by which PBEF-NAD+ cascade exerts brain protection following ischemia in primary cortical neuronal cultures. Using different approaches including confocal imaging, immunocytochemistry, molecular biology and Western blotting, I found that enhancing PBEF mediated NAD+ biosynthesis effectively reduced glutamate excitotoxicity and oxygen glucose deprivation (OGD) induced neuronal death, AIF translation, caspase-3 activation, mitochondrial fragmentation and impairments of mitochondrial function and biogenesis. Finally, in Chapter four, I investigated the effect of neuronal PBEF on the regulation of the motor system using a novel projection neuron-specific and inducible conditional PBEF knockout mice, i.e., Thy1-YFPCreERT2: Pbeff/f mice, in which deletion of PBEF can be achieved by tamoxifen administration. I observed that ablation of PBEF in the projection neuron resulted in muscle atrophy, progressive motor dysfunctions, impairments of synaptic connection at neuromuscular junctions, motor neuron loss and widespread astrogliosis and microgliosis. These results provide novel insights into the development of potential therapeutic strategies for cerebral ischemia and motor disorders based on PBEF-NAD+ cascade.
Microscale liquid dielectrophoresis for multiphase fluids manipulation
Authors:   , Jiao Jian
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Microfluidics has a bright future in the biomedical and biology fields. A system level integration that can provide efficient communications among multi-functional units and synchronize the flow rate is the key to unlock the full potential of microfluidics. The microscale gas-manipulation is essential for an integration platform; however, it is extremely underdeveloped at present due to leakage control and high compression ratio requirements. Differently from conventional approaches, we propose a confined liquid segment as an actuating medium. Liquid dielectrophoresis control, surface tension modifications, and geometric optimizations are applied to figure out the interplay of the liquids' adaptability and resistivity in a dynamic manner. Four different designs with a leak-tight feature and sub-nanoliter controllability are verified both theoretically and experimentally. The advantages of liquid usage as an actuation medium are highlighted further in a bio-mimic approach. The simplicity and integral capacity of liquid dielectrophoresis for dynamic fluids controls are predicted.
Fluorescent sensors for the detection of glucosamine and thiaminase
Authors:   , Tran Tam Minh
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Fluorescence chemical sensing is a highly important tool in science and industry with many applications in pharmaceutical screening, cell respiration, biological process control as well as biological isolation. Discussed herein is a brief introduction to bioanalyte detection using novel fluorescent chemical sensors for important biomolecules. First, a new fluorescent chemical sensor for glucosamine is reported. The sensor is based on a boronic acid-containing coumarin aldehyde and shows excellent selectivity for glucosamine by forming a boronic ester with the sugar diol as well as an iminium ion with the amine group of glucosamine. The sensor successfully discriminates glucosamine over other similar biomolecules in terms of both fluorescence intensity and binding affinity. This method provides a new concept for the design and synthesis of very selective turn-on optical sensors for selective detection of multi-functional biomolecules. Second, two new fluorescent molecules have been developed for thiaminase: one used to measure thiaminase activity and the other one used to inactivate this interesting enzyme. The thiaminase sensor was designed based on a PET mechanism. The internal quenching of the fluorophore (6Hex) by the attachment of a pyrimidine group makes it non-emissive. Under the action of thiaminase (representative by bisulfite), the free pyridine is released, which results in an increase in fluorescence. In addition to the thiaminase sensor, a red fluorescent, selective, irreversible inhibitor has also been synthesized. The inactivation of this interesting molecule has been confirmed by both plate assays and fluorescent experiences. Inactivation was found to go to completion if given sufficiently long incubation, and to be irreversible.
A study of intergroup contact theory : using storytelling to increase awareness of lesbian and gay older adults in long-term care settings
Authors:   , Pelts Michael D.
Published: April 2021

The population of older adults is growing rapidly. Among the aging population are large numbers that identify as lesbian or gay (LG). LG older adults are less likely to have partners, spouses or children and experience disparities in health that suggest that may need long-term care (LTC) services at rates higher than the general population. Even though LG older adults are at high risk for neglect or being underserved, they prolong assessing LTC in fear of discrimination. The need for programs that increase the awareness of LG older adults among LTC staff has been identified as a needed first step to address this issue. This study used intergroup contact theory as a guide to develop storytelling as a training modality to increase awareness of LG older among LTC staff. Results show that storytelling had a positive influence on LTC staff member's attitudes toward LG older adults. More work is needed to measure the effects of storytelling at different intervals to see if the effects are maintained over time and to measure LTC staff member's behaviors toward LG older adults.
Development of a composite acellular tissue graft for musculoskeletal tissue engineering
Authors:   , Smith Sarah Elizabeth
Published: April 2021

A composite acellular tissue graft comprised of decellularized tendon conjugated with nanomaterials has been developed for musculoskeletal tissue engineering applications. The focus of this dissertation is on the development of composite grafts derived from decellularized human tendon conjugated with gold nanoparticles and hydroxyapatite nanoparticles for use in anterior cruciate ligament (ACL) reconstruction. Gold nanoparticles are used to promote remodeling, cellularity, and biological incorporation of grafts. Hydroxyapatite nanoparticles are used to promote osseointegration, cellularity, and to enhance the graft/bone interface. These composite grafts along with several other variations, were characterized in vitro using a variety of cell-based assays including cell viability, cell proliferation, and cell migration assays. Two in vivo studies were conducted. A green fluorescent protein (GFP) porcine model was investigated as a new method to evaluate host tissue integration into soft tissue grafts as well as the in vivo biocompatibility of subcutaneously implanted composite grafts. Results demonstrate biocompatibility and remodeling of composite grafts and the value of using the GFP model as a qualitative method for assessing host tissue integration. A rabbit ACL reconstruction model was used to investigate graft remodeling in addition to the overall viability of using composite grafts to serve as a functional ACL replacement. Results demonstrate successful replacement of ACLs using composite grafts with enhanced remodeling from the addition of nanoparticles. Overall, studies demonstrate the success and potential further application of using composite grafts for musculoskeletal tissue engineering applications. Future studies will include expanding development of variations of these composite materials to address additional clinical needs.
Using animated graphics as a teaching tool in patternmaking: a comparison of delivery methods
Authors:   , Boorady Lynn M. (Lynn Marie)
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This study concerns itself with evaluating the effectiveness of teaching a visual topic, such as patternmaking, via a computer. The visual topic being explored, patternmaking, was taught to three levels of undergraduate students at different universities in the Midwest. This paper discusses the outcomes of patternmaking being taught in a traditional lecture style and compares it to the same instruction received through a computer-based animation program. It was found that the most difference in learning outcomes was within the subject groups in the lowest educational level. There was no difference found in the outcomes between the two higher educational level groups. Attributes of the subject groups which may account for the success of this style of learning include prior experience in sewing complete garments and overall GPA. Additional research and improvements to the animation is discussed. Suggestions are made on how to utilize web-based learning in the design curriculum.
Exploring the relation between social anxiety and depression in youth: the roles of friendship and peer acceptance
Authors:   , Marien Wendi E.
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This study examined whether problems establishing and maintaining positive, supportive relationships with peers may mediate the relation between social anxiety and depression in youth. In particular, structural equation modeling was used to evaluate models containing friendship quality and peer acceptance as mediators. Results, based on a school sample of 539 3rd, 5th, 7th, and 9th graders, indicated that peer acceptance partially mediated the relation between social anxiety and depression. However, friendship quality did not mediate the relation between social anxiety and depression, because social anxiety was unrelated to friendship quality. Few sex and age differences in the relations among study variables were found. However, social anxiety was a significantly stronger predictor of lower peer acceptance for girls than for boys. Results also indicated that having a high quality friendship may buffer youth who are not well-accepted by peers from experiencing symptoms of depression, in that lower acceptance by peers significantly predicted increased depression for youth who reported low friendship quality; however, level of acceptance was unrelated to depression for youth who reported high friendship quality.
Metabolic and functional consequences of adenylate kinase deficiency in skeletal muscle
Authors:   , Hancock Chad R.
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The primary function of skeletal muscle is to generate tension, and this ultimately occurs through ATP utilization. An increase in ADP and a depression in the cellular energy state are thought to be limited by the adenylate kinase (AK) reaction during high energy demands. AMP production through AK is also thought to be important for metabolic signaling, particularly during moderate energy demands. Thus, AK deficiency in muscle was evaluated during highly demanding and moderately demanding muscle contractions, using the AK1 knockout mouse (AK1-/-). The results demonstrate that AK deficiency leads to a marked elevation in free-ADP (1.5mM) at high energy demands, many fold greater than previously thought possible. These results call into question previously held views concerning the energy required for normal muscle function, because the performance was remarkably tolerant of ADP accumulation. At lower energy demands, AMPK phosphorylation was tempered in AK1-/- muscle consistent with reduced AMP production. Interestingly, other indicators of AMPK activity suggest that AMPK activation occurs normally, despite reduced AMPK phosphorylation. Thus, AK is critically important for the management of ADP during high energy demands, and may result in altered metabolic signaling at low energy demands.
Killing them with kindness: a meso-dialectical study of the conceptual formation of humane and inhumane in the no-kill animal shelter movement
Authors:   , Martindill C. Michele
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This research begins with one question: What is humane about humane? In the context of the no-kill animal shelter movement this study examines the social processes through which different conceptualizations of humane and inhumane have historically emerged and how the concepts of humane and inhumane shape relationships among human animals as well as human animal relations with other animals. In short, the no-kill animal shelter movement regards shelters that practice so-called euthanasia as inhumane and refers to them as kill shelters. The meso-dialectical perspective, an attempt to merge mesodomain analysis with a dialectical approach to historical institutionalism, initially allows me to question linkages and contradictions among organizations within social movement fields. I use the meta-power perspective to look at the structure of power and how relational control of the available conditions for action is accomplished. Autoethnography and ethnozoology are the methodologies used in this case study of Happy Tails Animal Sanctuary, an organization affiliated with the no-kill animal shelter movement. My memories of working in animal shelters and as a movement member are prominent along with discourse analysis focused on newspaper articles, government documents, websites and television programs. This study explores movement ethics as they relate to movement ethos, the social processes through which animals are commodified and no-kill movement symbolism as a factor in institutionalizing racism and other social inequalities. The actual killing practices comprise the final area of inquiry. Anthropocentric and speciesist views of the social world that dominate the existing body of sociological literature are regarded as problematic.
"If the wizard is a wizard who will serve" : the movical and shifting receptions of the St. Louis Municipal Opera and Royal Shakespeare Company's stage adaptations of MGM's "The Wizard of Oz"
Authors:   , Zank Ronald J.
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] L. Frank Baum's The Wizard of Oz has been seen in many forms throughout the 20th and 21st centuries. One ilmof the most recognizable forms is the 1939 MGM film. This notoriety has resulted in three different stage musicals having been written based on the film. These are examples of a trend known as the "movical"-- a stage musical based on a film. The movical has been an increasing trend in recent years, with the number presented on Broadway and in London increasing with each decade, but little scholarship has been devoted to this. Drawing from scholarship in Adaptation Theory and Reception History, this study uses a Cultural/Historical model to examine the development of two of these musicals, one staged by the Municipal Opera of St. Louis, one by the Royal Shakespeare Company. By examining how these works were adapted from the film, including the critical and audience reception, as well as the creators' interpretation over many years, this study serves as a model for a larger project, examining a broader range of film-to-stage musical adaptations, determining the key factors in their critical success or failure.
The effect of focused response to intervention on math scores
Authors:   , Blau Herman M.
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.]
Functional data analysis : children's mathematical development
Authors:   , Nicholas Alan
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Bailey et al. (2014) suggested that children's mathematical development is related more to trait characteristics than to prior mathematical development. However, their study analysis was designed to examine trait and state effects that did not vary flexibly across grades. This may lead to statistical bias in estimating the magnitude of effects, as well as educational interventions that are not targeted appropriately in time. We utilize both functional data analysis (FDA) and mixed FDA approaches to describe in detail grade-on-grade changes in the magnitude of trait and state effects. Mixed FDA methodology confirms the scientific hypotheses from Bailey et al. (2014) in a very general model setting. It acommodates both flexibly varying regression effects and testing of statistical hypotheses about them. In particular, trait terms account for 81.6% of variability in mathematical development vs. 68.2% for prior mathematical development. Additionally, of the four 'mathematical cognition' terms, the effects of simple addition and number line were not significant and these two terms were dropped out of the model. The effect of prior reading was not significant either. The effects of intelligence and prior fluency of processing the magnitudes associated with Arabic numerals were about constant over time. Skill at solving more complex addition problems became increasingly important over time, revealing an overall U-shaped pattern; central executive effect revealed an overall inverted-U pattern. With the possible exception of the central executive and complex addition, the pattern suggests that despite grade-to-grade differences in the significance of individual state and trait terms, the magnitude of the estimates of the effects of these terms is consistent across grades. Notably, in terms of relative magnitude, the regression term effects in first grade were in the same order as in 8th grade. We are thus able to answer research questions related to potential educational interventions in each grade that may improve children's mathematical development.
Dynamic and efficiency characteristics of an inlet metering valve controlled fixed displacement pump
Authors:   , Wisch Julie Kay
Published: April 2021

This project developed the inlet metering system. An inlet metering system represents a new option in hydraulic pump design. Traditional pressure controlled hydraulic pumps rely on either swashplate displacement (for variable displacement pumps) or bleed off valves (for fixed displacement pumps). Variable displacement pumps require mechanically complex parts which are expensive to machine and prone to break down. Bleed off valves represent a significant loss in system efficiency. In contrast, the inlet metering system is able to make use of a fixed displacement pump (which is relatively inexpensive and mechanically robust) and a two-way spool valve. This dissertation goes through the process of designing the valve and pump dimensions, presents a theoretical dynamic analysis, studies the control law associated with this pump, and examines the energy requirements associated with inlet metering system operation. A prototype of the design was constructed and experimental data was used to validate the efficiency analysis. The major finding associated with this work was that the inlet metering system can be designed to display a first order pressure response. This means that when the inlet metering system is operated, the actual pressure in the system will never exceed the desired pressure. In contrast, traditional hydraulic systems will display up to 60% pressure overshoot, meaning the systems must be designed to handle pressures significantly greater than operating pressures. Additionally it was found that the inlet metering system is more efficient than using a bleed off valve, but less efficient than using a variable displacement pump.
The communication and psychology of identity on mobile dating apps for men who have sex with men
Authors:   , Miller Brandon
Published: April 2021

The present study investigated the use of mobile dating apps for men who have sex with men (MSM), the privileging of masculinity in these online spaces, and related effects on attitudes about masculinity, the body, and the self. Using self-categorization theory as a framework, the study explored how men infuse masculinity/femininity and body language into their profiles in order to create symbolic boundaries between a masculine in-group and a feminine out-group, in the process further promoting an in-group bias for masculine partners. Findings indicated a clear preference for masculinity, both generally and in the form of the muscular male body. Drawing on selective self-presentation and the online disinhibition effect, the current work also investigated howpatterns of usage and personal attitudes impact photographic self-presentation, how the presence of face-disclosing and/or shirtless photos impact the use of language, and how visual self-presentation is related to demographic and attitudinal variables. The results indicated a connection between outness and face-disclosure, as well as between the amount of usage of MSM-specific mobile dating apps and face-disclosure. Menâ€™s use of shirtless photos was significantly related to age, self-perceived masculinity, antieffeminacy attitudes, and drive for muscularity. Finally, priming theory was used to examine the relationship between MSM-specific mobile dating app usage and attitudes about menâ€™s own and othersâ€™ masculinity/femininity and their bodies, as well as feelings of esteem and connectedness. Findings indicated connections between usage and self-perceived masculinity, internalized homonegativity, collective self-esteem, and body dissatisfaction, as well as social connectedness and anti-effeminacy attitudes for some men. Age, race, relationship status, education level, geographic location, and outness all served as important moderators. Constructions of gay masculinity have been associated with many issues, including risky sexual behavior, body dissatisfaction, disordered eating, lowered self-esteem, and racism. The current research advances our understanding of how MSM engage with masculinity/femininity and body language in a new media context, as well as the relationship between usage of MSM-specific mobile dating apps, psychosocial attitudes, personal feelings of esteem and connectedness, and photographic self-presentation strategies.
Mechanisms of clostridial neurotoxin binding and entry
Authors:   , Burns Joshua R.
Published: April 2021

The botulinum neurotoxins (BoNTs) and tetanus neurotoxin (TeNT) make up the clostridial neurotoxin (CNT) family. The CNTs are produced by Clostridium botulinum and Clostridum tetani respectively, and are the most potent human protein toxins. Eight CNT family members have been identified: seven botulinum neurotoxins (A-G) and tetanus neurotoxin (TeNT). Intoxication with BoNT is largely restricted to peripheral motor neurons, and results in flaccid paralysis. TeNT is sorted into a retrograde axonal trafficking pathway, transported to the central nervous system, and causes spastic paralysis. The CNTs are typical AB toxins. They are secreted as ~150 kDa single chain proteins that undergo processing to produce a disulfide linked, dichain active form. The â€œAâ€ or active domain is ~50 kDa zinc dependent protease, also known as the light chain (LC), that inhibits synaptic vesicle fusion with the plasma membrane through cleavage of soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins. LCs cleave one of three neuronal SNARE proteins, preventing synaptic vesicle exocytosis. The â€œBâ€ subunit is ~100 kDa, and contains a heavy chain translocation domain (HCT) and heavy chain receptor binding domain (HCR). Through an unclear mechanism, the HCT undergoes a conformational change upon acidification and forms pH dependent channels, facilitating transport of the LC into the neuronal cytosol. The HCR binds neuronal receptors on the presynaptic membrane of Î±-motor neurons. In order to explain the neuronal specificity of the CNTs, a dual receptor model was put forward. One co-receptor is ganglioside, a glycosphingolipid with a carbohydrate backbone decorated with sialic acids and a sphingolipid anchor. To satisfy the coreceptor model, the CNTs bind either a resident synaptic vesicle protein or a second ganglioside. The focus of this work was to examine mechanisms of CNT binding and translocation to better understand CNT pathogenesis. Special emphasis was placed on understanding the ganglioside binding interactions in retrograde axonal trafficking, BoNT/A1 and A2 subtype specific ganglioside interactions, and the role of receptor contributions in CNT translocation. Improving our understanding of basic mechanisms of CNT pathogenesis, including binding, entry, and translocation we can improve inhibitor designs, vaccine development, and further CNT platforms for pharmaceutical development.
Library services and early literacy approaches in public libraries for deaf and hard of hearing children
Authors:   , Bushman Bobbie
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Children's librarians are challenged to provide inclusive programming in today's public libraries. There is a current trend in public libraries to provide special needs programming for children. This dissertation focuses on library programming for deaf and hard of hearing (D/HoH) children who visit U.S. public libraries. The American Library Association (ALA) states that hearing children need to know six pre-reading skills to be ready to read; however, some of these pre-reading skills focus on singing or rhyming which is difficult for D/HoH children. Grounded theory is "a systematic, inductive, and comparative approach for conducting inquire for the purpose of constructing theory" (Bryant and Charmaz 2007). This grounded theory research studies the programs, services, and story times that are implemented and modified for D/HoH children in U.S. public libraries. This study began with sending out a recruitment script and questionnaire found in Appendix A and B, respectively, which reached nearly 500 medium to large sized U.S. public libraries. Fifteen participants volunteered to be interviewed, and eleven were interviewed. Interviews were analyzed using open and axial coding, which is typical in grounded theory. Preliminary data and a review of literature on literacy acquisition for D/HoH children suggested that D/HoH children do not progress in four of the pre-reading skills outlined in the ALA's early literacy program, Every Child Ready to Read (ECRR), in the same way that hearing children do. Phonological awareness is largely not utilized by D/HoH children in learning to read. D/HoH children are also likely to build vocabulary, develop print motivation, and approach narrative skills differently than hearing children. This grounded theory research developed the model of successful library services and modifications to D/HoH children to explain which services, early literacy instruction, staff training and programs public libraries provide to children who are D/HoH. This research project also inquires about what kinds of modifications are made to serve D/HoH children, and what the impetus was for providing library services to deaf children. The first stage of the model highlights staff attitude as being warm and welcoming, taking initiative, and not seeing D/HoH as a disability. The second stage described the impetus for providing services as encountering a D/HoH patron in the library, knowing a disabled person in a librarian's personal life, or by encountering a nearby agency that serves D/HoH. In the third stage, librarians made accommodations by being inclusive in programming, providing ASL programming, or facilitating visual phonics instruction in place of phonological awareness instruction. In the fourth and final stage, this model reported outcomes such as educating both hearing and D/HoH individuals and building a sense of community.
Simulation aided analysis and experimental study of polyurethane polymerization reaction and foaming process
Authors:   , Al-Moameri Harith H.
Published: April 2021

A MatLab simulation model was developed to simulate polymerization reactions, gel point times and foam formation. The simulation is based on the simultaneous solution of typically 25-80 ordinary differential equations that describe elementary reactions, energy balances, and mass transfer. Laboratory polymerization experiments were performed to evaluate the accuracy of the simulations, including setting up experimental systems and measurement of temperature, height, and viscosity profiles of the urethane systems. The performance of physical and chemical blowing agents were simulated with mass transfer of the blowing agent estimated as a function of reaction temperature and resin viscosity. The simulation code of polyurethane reactions allows the studying of variables that are impossible to obtain in labs like the rate of foam's cell growth and pressure inside the cells. Also, simulation provides insight into mechanisms such as how attaining a reasonable maximum reaction temperature is important to properly cure foams and avoid foam shrinkage. The impact of mass transfer limitation of the reacting moieties was successfully simulated based on three fundamental approaches. Further modeling shows the ability to reduce the number of parameters used for simulating urethane reactions by considering the viscosity dependent term for the frequency factor of Arrhenius equation. Finally, the simulation studies of this research provide fundamental insights into the mechanism of homogeneous and catalytic reactions. This research process places high demands on identifying and testing highly-impactful fundamental mechanisms during polymerization that have not previously been identified.
An exploratory cross-sectional survey study of elementary teachers' conceptions and methods of STEM integration
Authors:   , Arnone Kathryn Ann
Published: April 2021

Because elementary teachers are typically responsible for teaching all subjects, there is a unique opportunity for integrative approaches to teaching iSTEM Education at the elementary level (Becker and Park, 2011). However, there is a need for professional development if teachers are to be successful in teaching iSTEM Education (NRC, 2011), as elementary teachers may lack strong content knowledge in STEM disciplines (Ginns and Watters, 1995; Trygstad, 2013; Honey et al., 2014; Fulp, 2002; Ma, 1999; Hanover, 2012). Elementary teachers are prepared as generalists--they take few courses in STEM content, and experiences with iSTEM Education in their teacher preparation programs are rare (Fulp, 2002). Beyond the need for professional development related to STEM content knowledge, however, we know very little about the unique needs of elementary teachers regarding instructional approaches to iSTEM Education. This study examines and describes the ways in which elementary teachers conceptualize iSTEM Education and the integrative approaches they use when teaching STEM content, with the intent to inform the development of elementary specific iSTEM Education professional development.
Trace Mississippi Valley-type lead-zinc mineralization : origins and relationship to midcontinent MVT ore districts
Authors:   , Field Joshua D.
Published: April 2021

The North American mid-continent is known for its large Mississippi Valley type (MVT) ore districts. Deposits with the same mineralogy but at much smaller scales, known as trace MVT occurrences, are also widespread throughout the mid-continent, and have been found in Paleozoic strata ranging from the Cambrian to the Pennsylvanian. This research attempts to determine if trace MVT occurrences differ from their ore district counterparts in magnitude of scale only, or if the two types of deposits are formed from fundamentally different processes. Lead isotope compositions of the trace sphalerite matrices indicate that a significant portion of the Pb was derived from igneous basement, but a lack of collinearity with the midcontinent MVT ore districts indicates that the basement-derived Pb was diluted by Pb from other sources. Negative ?34S values of trace sphalerite matrices favor incomplete biological or thermochemical reduction of seawater sulfate reservoirs, and a lack of correlation between Pb and S isotopes shows they were not transported together to the site of mineralization. Primary, sphalerite-hosted fluid inclusions have Th values and salinities that suggest trace MVT occurrences did not form as a result of regional trends of both cooling and dilution. The compositions of these fluid inclusions resemble sphalerite ore-stage mineralization rather than gangue-stage fluids, but the general lack of detectible methane suggests conditions that precluded the presence of abundant reduced sulfur. Similar sphalerite matrix compositions show that any differences between trace and ore district fluids in major and minor element composition did not affect the ability of the trace fluids to transport metals in solution. Forest City basin trace occurrences have Cl/Br ratios which indicate several of them precipitated from brines derived from evaporatively concentrated seawater, but do not constrain seawater age. Reaction path models showed that trace occurrences from the FCB could be evolved from any Paleozoic-aged seawater, but trace fluids from the Greater Upper Mississippi Valley and Illinois basin regions were successfully modeled only by Devonian brines. Collectively, any variations observed do not appear to have been mitigating factors in controlling the scale MVT mineralization, but low to undetectable methane concentrations indicate either that metal-rich fluids did not encounter large quantities of organic matter, or that conditions during trace mineralization were too oxidizing for reduced sulfur to have been abundant.
A study of social comparisons and their effects on high school choir directors
Authors:   , Kitchel Laura
Published: April 2021

This study was designed to examine social comparison usage by high school choir directors, and possible attributes that may affect the types of comparisons that are utilized. Directors from four Midwestern states were invited to participate in a survey designed to answer research questions pertaining to the extent to which they engage in social comparisons, the different ways that they socially compare, and potential relationships between job attributes, perceived control, and social comparison types. Three hundred and sixty-three participants returned usable surveys for a response rate of 31.6 percent. Results indicated that directors were engaging in social comparison, mostly to seek information, problem solve, and validate opinions. These comparisons were upward assimilative, which research has found to have positive emotional outcomes, such as inspiration and admiration. Two attributes, perceived control and number of years taught, played a role in three comparison types, Upward Assimilation, Upward Contrast, and Downward Assimilation. A qualitative component of the survey confirms that the participants were engaging in upward assimilative behaviors, but also provide evidence that some directors experienced the negative effects of comparisons, as well. Future research to examine the possible effects and emotional outcomes of social comparison use by choir directors.
The influence of social support on teacher self-efficacy in novice agricultural education teachers
Authors:   , Korte Debra S.
Published: April 2021

Teacher self-efficacy affects student achievement, job satisfaction, and teacher retention. Although the benefits of social support have been extensively studied in medicine and psychology, limited research has been completed in education to evaluate the ways in which social support influences teacher self-efficacy. The purpose of this descriptive-relational study was to determine the influence of sources and types of support on teacher self-efficacy in novice agricultural education teachers. The target population was novice teachers of agriculture from Illinois (n = 192) and Indiana (n = 104). Teachers' perceptions of support from three non-school sources (e.g., spouse or partner, family, friends) and six school sources (e.g., administrators, teachers at school, teachers in FFA section or district, students, parents, community) of support within three support constructs were used to predict the contribution of social support on teacher self-efficacy. Novice agricultural education teachers' perceptions of support from school sources -- predominantly students and community -- explained 25.3 percent of the variance in teacher self-efficacy. Whereas mastery experiences are widely recognized as the primary source of self-efficacy, the results from this study imply the support (i.e., verbal or social persuasion) novice agricultural education teachers perceive from students and community are the most significant predictors of teacher self-efficacy. These findings advocate the need for novice teachers of agriculture to develop quality relationships with students and community members to increase teacher self-efficacy and potentially improve teacher retention.
The comic core : a theory of teaching sequential art narratives
Authors:   , Kremer Nicholas T.
Published: April 2021

This research study develops a theory of effective pedagogy for teaching sequential art narratives grounded in the experiences of six graduate students and twelve junior high school students who studied graphic novels within their respective English Language Arts courses, which coalesced during a shared field teaching experience. Video recordings of all class sessions, field notes taken during observations, student interviews, and student compositions (both prose and multimodal) comprised the data set used to develop the theory, which establishes that sequential art narratives should be taught in conjunction with visual literacy modeling, quality mentor texts, and frequent opportunities for student collaboration, creative composition, and transmediation experimentation within a gradual release of (instructor) responsibility framework. A visual model of the proposed theory is included in the findings.
Two applications of lifecycle models : teachers' retirement under time-varying pension rules and the income-health correlation in PSID
Authors:   , Wu Weiwei
Published: April 2021

This study uses two structural models to predict public school teachers' retirement decisions and explore the correlations among people's health, occupational choices, and labor income. Extensive literature suggests that the early exit of the late career teachers is inefficient. The first chapter uses the option value model introduced by Stock and Wise (1990) to analyze the retirement behavior of public school teachers in Missouri (MO) and simulate the effect of several retention policies. The existing studies failed to consider the sample selection bias of the late career teachers and did not consider the time-varying pension rules. I propose two algorithms that fix the sample selection bias, and I examine the competing theories on teachers' expectation of the timevarying pension rules. My modified model produces an excellent out-of-sample fit to the observed data. Simulations of counter-factual experiments show that the MO pension enhancements lead to earlier retirements, and well-designed retention policies can delay retirements. The second chapter builds a life-cycle model to explain the widely acknowledged income-health correlation. I explore the dynamic relationships among occupations, health, and earnings observed in Panel Study of Income Dynamics (PSID). The simulations from the calibrated model fit the data well. Several simulation-based counter-factual experiments show that the occupations are mainly decided by education. "Manual" occupations lead to faster health deterioration and lower income compared to "non-manual" occupations. Given an occupation, people's health affects the labor supplied and labor income. Meanwhile, labor income affects health level through occupational choices, which is the main source for the health-income correlation. These two applications reveal that life-cycle models can successfully model teachers' retirement and the health-income correlation, which can then help in evaluating the potential policies on retaining experienced teachers, and also help in exploring the correlations among health, occupation, and labor income.
Influences of pluton growth on magma crystallinity, aureole rheology, chamber stability and metamorphic fluid flow : numerical modeling of the growth of Papoose Flat pluton, White-Inyo Range, California
Authors:   , Chen Yanying
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Magma is a molten rock that rises in the Earth's crust because it is hotter and less dense than the surrounding rocks. If the magma finds a way to the surface, a volcanic eruption occurs. When the magma cannot find a path upwards, it pools into a magma chamber. This process also deforms the cold country rocks (contact aureole) around it by pushing them and warming them up. Metamorphic reactions, especially fluid generation reactions, occur in the country rocks during the process. Magma chambers cool down at depth to form different types of igneous rocks (plutons), such as granite. Today, we still have many questions about what goes on during magma emplacement. For example, how do magma chambers grow? Are they emplaced effectively instantaneously by injection of large volumes of magma, or incrementally with magma injections accumulating over thousands to millions of years? Unlike studies of lava flows on the surface, we have had to rely on methods to "see" deep into the Earth. Numerical computer modeling is one of the methods. The Papoose Flat pluton in the White-Inyo Range, California, is one of the best examples of forcefully emplaced plutons within the crust, having country rocks surrounding it that deformed plastically without fracture (ductile deformation). I used the computer language Fortran to build pluton growth models and explore evolution of the pluton and its aureole. Instantaneous intrusion models and incremental intrusion models (continuous and episodic) were constructed. I explored how the frequency of magma input to the bottom of the pluton affects ductile width of the contact aureole, crystal distribution within the pluton, eruptibility of the magma chamber, and expulsion of the metamorphic fluid from the ductile aureole. The modeling results show that the ductile region above the Papoose Flat pluton is related to thermal weakening. The ductile region in the incremental emplacement models is ~110 m thick, matching the observed thickness. It is 10 times thinner than in the instantaneous growth model. The pluton remains hot and only partially crystalline at the bottom throughout incremental growth. When a pluton grows by lowfrequency but high-flux injections, the chamber overpressure can be as high as 105 MPa. Dike propagation will occur under this condition. Conversely, the growth of magma chambers is favored by high-frequency injections of small melt batches. Metamorphic fluid is likely to be expelled from ductile aureoles by waves of self-propagating, fluid-filled porosity. However, when the growth rate of a pluton is high, fluids can be squeezed out because of compaction imposed by the growing pluton from below.
Challenge stressors, hindrance stressors, and psychological strain : the role of appraisals and goal orientations
Authors:   , Moake Timothy R.
Published: April 2021

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The challenge-hindrance stressor framework suggests that most workers experience challenge stressors positively and hindrance stressors negatively. However, research has shown that both types of stressors are positively related to psychological strain, a negative outcome. Using the transactional theory of stress, I examined whether and how individuals' appraisals of challenge and hindrance stressors and their goal orientations influence the positive relationships between both types of stressors and psychological strain. I surveyed 278 full-time employees from various occupations twice over a two-week span. My findings revealed that despite challenge stressors' positive conceptualization, individuals appraise them negatively as constraints. Additionally, I found that constraint appraisals are one mechanism that influences the positive relationship between challenge stressors and psychological strain. Lastly, my results also indicated that individuals with a stronger learning goal orientation are more likely to appraise both types of stressors as opportunities and individuals with a stronger performance-avoid goal orientation are more likely to appraise both types of stressors as constraints.