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Title: Social-ecological systems, values, and the science of "people management"
Creator: Piso, Zachary Amedeo
Date: 2017
Collection: Electronic Theses & Dissertations
Description: This dissertation interrogates a shift in environmental science, policy, and management toward conceptualizing the environment as a social-ecological system. Social-ecological systems science reflects an interdisciplinary effort to understand how individuals and communities achieve their environmental goals through the institutions that they maintain. Though the paradigmatic institutions concern economic behavior (e.g. property rights institutions), the field embraces the social sciences...
Show moreThis dissertation interrogates a shift in environmental science, policy, and management toward conceptualizing the environment as a social-ecological system. Social-ecological systems science reflects an interdisciplinary effort to understand how individuals and communities achieve their environmental goals through the institutions that they maintain. Though the paradigmatic institutions concern economic behavior (e.g. property rights institutions), the field embraces the social sciences broadly, with contributions from sociology, anthropology, geography, political science, and so on. That said, social science is fairly narrowly conceived; leaders in the field stress that they are studying social mechanisms in order to predict and manage social behavior. In a popular textbook on the subject, Fikret Berkes and Carl Folke stress that "resource management is people management" and call for a social science of this management.Social-ecological systems scientists have generally neglected the ethics of people management-for the most part they subscribe to a fairly typical fact/value dichotomy according to which scientists describe social-ecological systems while managers and policymakers prescribe actions in light of these descriptions. Following several philosophical traditions (in particular pragmatist philosophy of science), I call attention to the ways that social-ecological systems science is value-laden. I take environmental pragmatism to provide a roadmap for conducting social-ecological systems science ethically. Environmental pragmatists stress that science is always embedded in practical problem-solving activities that presuppose particular goals for, and side constraints to, inquiry. Many traditions in the philosophy of environmental science embrace social science for the specific role of facilitating this deliberation, but these traditions do not seem to anticipate the explanatory ambitions of social sciences. This leaves unaddressed several pertinent questions about how social explanations work (i.e. how functional distinction structure inquiry), which have very practical implications for which social science disciplines should be included in a collaboration and how social and ecological knowledge should be integrated. For example, most social situations are characterized by property rights institutions, cultural traditions, political alliances, and other social institutions within the purview of particular social science disciplines, but researchers are not reflexive about whether to explain environmental change according to one set of practices or another.The dissertation traverses the following terrain: the first chapter more carefully motivates the questions above regarding the need for ethics and the promise, but present inadequacy, of environmental pragmatism to meet this need. Chapter two attends to Dewey's theory of inquiry, in particular the dialogical dimension of inquiry that authorizes warranted assertions. Through reflection on Daniel Bromley's volitional pragmatism and a debate between Richard Rorty and hermeneutic social scientists, chapter three attends to the way that social science structures inquiry in order to intervene in the normative practices of a community. Chapter four analyzes social-ecological explanations in order to locate normative and evaluative assumptions that should be accountable to democratic deliberation. Finally, chapter five redescribes interdisciplinary integration as an ethical project where decisions about the centering and decentering of different sciences is as much ethical as epistemological.
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Title: The meaning of teaching mathematics : teacher positionings as embedded in algebra teachers' guides
Creator: Suh, Heejoo
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Teacher educators have been examining the professional status of teaching, including defining central practices of teaching, comparing teaching to other professions, and understanding teachers’ own perspective via interviews, surveys, and observations. The present study intends to contribute to the discussion by examining the meaning of teaching as reflected in teachers’ guides. I chose to examine teachers’ guides because they are known to have impact on teachers. Being a resource that is...
Show moreTeacher educators have been examining the professional status of teaching, including defining central practices of teaching, comparing teaching to other professions, and understanding teachers’ own perspective via interviews, surveys, and observations. The present study intends to contribute to the discussion by examining the meaning of teaching as reflected in teachers’ guides. I chose to examine teachers’ guides because they are known to have impact on teachers. Being a resource that is close to teachers’ everyday practices, curriculum materials inspire teachers with what they could do in their classroom. Educators intending large-scale educational reform pay attention to curriculum materials. Careful use of linguistic features therein could enhance thus further support teachers’ guides in effective communication with teachers.I investigated four 8 th grade Algebra teachers’ guides - TG, selectively chosen to represent variety. Drawing on positioning theory, I observed positionings regularly appearing in each of those four. Then I turned to idiosyncratically-observable positionings. Two research questions sought understanding of what teaching mathematics entails as presented in the TGs, hence how each guide constructs teaching mathematics. Last, I examined the guides’ linguistic features. This was for understanding the degree of teacher professional judgment acknowledged by the guides.My results indicated that, as constructed by each guide, teaching mathematics does not differ much across the guides. Those guides presented various types of knowledge as entailed in teaching mathematics. Compared to aspects on teacher professionalism in the literature, the guides occasionally addressed teacher research, interaction with colleagues, utilizing knowledge, and acknowledging uncertainty. In addressing these aspects, the guides in most cases did so with insufficient support. Examining idiosyncratic positionings, I found two types: i) positionings occurred idiosyncratic only, and ii) positionings occurred idiosyncratically in addition to their regular appearance. The latter can be classified into two types: a) one that succeeds the context of the communication actions associated with the general positioning, and b) one dissociated from the context. My linguistic examination of the guides suggested that they varied in their use of voice. Some are more directive, others are more suggestive, indicating different levels of acknowledgement of teachers’ professional judgment. In this dissertation’s last chapter, I present ways in which this study contributes to understanding of curriculum materials and of teacher professionalism. I end this dissertation with implications for curriculum authors, teachers, teacher educators, and researchers.
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Title: Integrating genomic selection and genome editing strategies to accelerate potato breeding
Creator: Enciso Rodriguez, Felix Eugenio
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "As a staple food, the potato (Solanum tuberosum L.) plays an important role in human nutrition and it is currently the third most important food crop after rice and wheat. However, the potato crop faces high production losses caused mainly by biotic factors. With the advent of cutting-edge technologies suitable for potatoes, there is an increasing possibility to accelerate genetic progress and variety generation. To contribute to the implementation of genomic strategies to accelerate potato...
Show more"As a staple food, the potato (Solanum tuberosum L.) plays an important role in human nutrition and it is currently the third most important food crop after rice and wheat. However, the potato crop faces high production losses caused mainly by biotic factors. With the advent of cutting-edge technologies suitable for potatoes, there is an increasing possibility to accelerate genetic progress and variety generation. To contribute to the implementation of genomic strategies to accelerate potato breeding, three different approaches were used. First, whole genome regressions were conducted using additive and dominant allele dosage models for late blight and common scab resistance in tetraploid potatoes. Multiple Single Nucleotide Polymorphisms (SNPs), contribute to late blight resistance, uncovering the introgression history for this trait whereas an unreported locus with a sizable contribution to common scab resistance was detected. Prediction accuracy assessments demonstrated that 90% of the genetic variance could be captured with an additive model, demonstrating the applicability of genomic prediction for tetraploid potato breeding. Second, a genome editing approach was implemented to breakdown the S-RNase -based self incompatibly in diploid potatoes. New S-RNase allelic variants, with flower-restricted expression, were identified in two self-incompatible (SI) diploid potatoes and mapped to chromosome I in a low recombination region. A dual single-guide RNA strategy was used to generate S-RNase knock-out lines producing premature stop codons on each targeted S-RNase allele. Self-compatibility was achieved in T0 knock-outs and stable transmitted to T1 lines. Additionally, Cas-9 free plants were also obtained. Plasticity in the self-compatible response was also observed in wild-type lines, presumably associated with non-stylar and environmental factors. Third, validation of the IPI-O4 -mediated suppression of the RB-based late blight resistance was conducted using in vivo and in vitro approaches. The hypersensitive response (HR) was confirmed when IPI-O1 was co-infiltrated with the RB gene from Solanum bulbocastanum using a heterologous system. However, HR was observed when IPI-O1 and IPI-O4 were infiltrated in transgenic potato lines carrying a synthetic RB gene containing a Coiled-Coil (CC) domain from S. pinnatisectum. Further work should be conducted to confirm this un-reported interaction. Similarly, we could not validate CC-dimerization using yeast-two hybrid assays and therefore more extensive experiments should be conducted to confirm this result. Ultimately, these genomic approaches open a new window to accelerate the generation of new potato varieties. Genomic selection strategies along with targeted mutagenesis will expand the boundaries of both approaches, reducing the potato breeding cycle considerably while maintaining genetic diversity, and providing access to genomic regions with low or null recombination in potatoes."--Pages ii-iii.
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Title: Analysis of drinking water quality and sanitation in a peri-urban area of Dar es Salaam, Tanzania
Creator: Ngasala, Tulakemelwa Mhamilawa
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "While the Sustainable Development Goal 6 called for universal access to water and sanitation by 2030, the challenge of achieving this goal seems daunting in the context of the bourgeoning peri- urban communities of the developing world. These areas are often in a regulatory grey area, receiving municipal water on an irregular basis and lacking sanitation and other basic services. And yet, SDG 6 recognizes that improving global health and wellbeing is critically linked to addressing this...
Show more"While the Sustainable Development Goal 6 called for universal access to water and sanitation by 2030, the challenge of achieving this goal seems daunting in the context of the bourgeoning peri- urban communities of the developing world. These areas are often in a regulatory grey area, receiving municipal water on an irregular basis and lacking sanitation and other basic services. And yet, SDG 6 recognizes that improving global health and wellbeing is critically linked to addressing this problem. A multi-method study of the peri-urban area of Dar es Salaam was conducted to determine the extent of the problem and to make recommendations for system-wide approaches to alleviate the risk of waterborne disease. Existing water sources in the area were identified. Water collection and storage practices were assessed at the household level to determine how water from relatively clean sources becomes contaminated. Escherichia coli (E. coli), nitrate, and total dissolved solid (TDS) were analyzed as indicators for the sewage contamination. Bivariate correlation and univariate regression analyses were used to identify the sources of contamination. The assessment focused on the relationship and association of water contamination with site-specific variables. The variable that had the highest negative impact to the water source was analyzed by using a groundwater flow and contaminant transport model as a tool to make recommendations for proper site-specific sanitation practices. Of the three water sources identified (city water, vendors, and domestic wells), water quality analysis showed that city water at the point of collection (POC) was deemed excellent, whereas it diminished at the point of use (POU) for all three water sources. Reasons for change in water quality at POU and POC were due to mixing of water from different water sources at homes during storage. Using a multinomial regression model, the main reason for mixing water was determined to be the dilution of the salty taste of well water (p < 0.05) and insufficient storage containers (p < 0.05). Of the three water sources identified, domestic wells were found to be the most contaminated. Further analysis on the domestic wells showed a significant contamination, where 80% of wells tested contained E. coli. Also, 58% and 81% of wells tested had concentrations of nitrate and TDS, respectively, that exceeded the WHO guidelines. Univariate regression analysis confirmed the association of contaminants with distance of a well from a sanitation system and well depth (p < 0.05). Groundwater transport modeling showed a strong correlation between the tracer and contaminants and the tracer and distance and helped identify the safe well setback distance that is specific to site conditions, soil type, and aquifer properties. Groundwater modeling was shown to be a good assessment tool for contamination within an aquifer system in urban overpopulated areas of developing countries. Our findings also indicate that the risk of exposure to waterborne disease comes from a combination of factors that involve multiple actors, from improved awareness and sanitation practices to improved regulatory oversight, supply practices, and sanitation technologies."--Pages ii-iii.
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Title: Exploring influences on couple therapist violence screening practices : a qualitative study
Creator: Parker, Nicole
Date: 2018
Collection: Electronic Theses & Dissertations
Description: Intimate Partner Violence (IPV) is a tremendous social problem with devastating consequences for survivors and loved ones, with effects that often last for generations. IPV not only affects the victim but it hurts society as a whole, and costs billions of dollars to the US economy each. Yet it is a preventable problem. Many couples who experience abuse seek solutions through couple therapy, yet most therapists working with couples do not directly address nor assess for the presence of...
Show moreIntimate Partner Violence (IPV) is a tremendous social problem with devastating consequences for survivors and loved ones, with effects that often last for generations. IPV not only affects the victim but it hurts society as a whole, and costs billions of dollars to the US economy each. Yet it is a preventable problem. Many couples who experience abuse seek solutions through couple therapy, yet most therapists working with couples do not directly address nor assess for the presence of violence, one estimate finding that only 4% of therapists follow guidelines to routinely screen for partner violence. Engaging couples in treatment when violence has not been assessed is dangerous for victimized clients and ethically perilous for the therapist. There is a healthy discourse in the IPV literature about how best to respond to violence in couples seeking treatment, but what is missing from this discussion is a thorough understanding of factors which influence therapists' couple violence screening practices. Guided by two theories, Ecological Theory and Role Theory, this qualitative study explores the many factors that influence clinicians in their screening practices around the topic of violence, and highlights the individual and contextual elements that govern clinical choices by the therapist. Data was gathered from clinicians working in a variety of contexts, and was analyzed using a thematic analysis approach. Findings contribute to a growing knowledge of literature that focuses on violence detection efforts within the field of mental health, and may inform educational and training policy.
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Title: Solid-state nuclear magnetic resonance studies of the structures, membrane locations, cholesterol contact, and membrane motions of membrane-associated HIV Fusion Peptide (HFP
Creator: Jia, Lihui (Scientist)
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Membrane fusion is the key step during HIV viral entry to cells, and the process is catalyzed by HIV membrane fusion protein gp41. HFP is the ~25-residue N-terminal domain of gp41 and is required for membrane fusion with significant decreases in fusion activity with point mutations. Both viral and host cell membrane contain ~30mol % cholesterol (CHOL), and HFP induced fusion is faster in membrane with CHOL. However, how HFP interacts with membrane lipids and CHOL is unknown. In this thesis,...
Show moreMembrane fusion is the key step during HIV viral entry to cells, and the process is catalyzed by HIV membrane fusion protein gp41. HFP is the ~25-residue N-terminal domain of gp41 and is required for membrane fusion with significant decreases in fusion activity with point mutations. Both viral and host cell membrane contain ~30mol % cholesterol (CHOL), and HFP induced fusion is faster in membrane with CHOL. However, how HFP interacts with membrane lipids and CHOL is unknown. In this thesis, we used the newly developed 13C-2H Rotational Echo Double Resonance (REDOR) solid-state NMR method to study the membrane location of HFP in chemically-native membrane environment. HFP is 13CO labeled at specific residue, and the membrane is deuterated at specific regions of the membrane using selective regions deuterated phosphatidylcholine (PC) and CHOL. We study HFP wild type, HFP_V2E and L9R mutants because these two mutants eliminate and decrease fusion respectively. HFP is predominantly β sheet structure in bilayer membrane for both HFP wild type and HFP_V2E mutant, HFP_L9R has a different structure and is likely helical. Both HFP and HFP_V2E mutant have major deeply-inserted membrane location contacting membrane center and minor shallowly-inserted membrane location contacting half way of one membrane leaflet. The HFP_V2E mutant has bigger fraction of molecules with shallower membrane location, which is consistent with the strong correlation between membrane location insertion depth and the peptide fusogenicity. HFP_L9R mutant has majorly deeply inserted into membrane.By comparing the HFP- PC and HFP- CHOL contact, there is preferential contact between HFP and CHOL vs PC at several residues including G5, G10 and G16. The free energy difference for contacting PC vs CHOL is ~ 0.57(5) kcal.mol-1 for T= 300K. HFP- CHOL contact geometry is successfully modeled by Swiss Dock and YASARA energy minimization with two strands antiparallel HFP (1→16/16→1 registry). There are two energetically favorable binding models between HFP and CHOL, from docking, energy minimization and consistency with REDOR results. The contact models reveal tilted and curved-up tail orientation of Chol_d7. Fusion may be catalyzed by matching the curvature of lipids contacting HFPs with the membrane curvature during the fusion intermediates like the stalk. Membrane motion perturbation by HFP is studied by static deuterium NMR from deuterium powder pattern spectrum, order parameter profile and T2 relaxation time. The DMPC-d54 spectrum becomes ~10% narrower in membrane without CHOL with 4% HFP and in membrane with 33% CHOL with 1% HFP. Accordingly, the order parameter of lipid acyl chain becomes ~ 1-10% disordered by HFP. However, the spectrum becomes 20% broader in membrane with 33% CHOL with 4% HFP, and the order parameter of lipid acyl chain becomes ~ 20- 30% ordered by HFP. With HFP at 37 °C, DMPC-d54 T2 decreases ~ 70 %, and the CHOL T2 decreases ~ 30%. T2 reduction is probably associated with increased membrane curvature induced by HFP. With greater membrane curvature, the C-D bond will experience more orientation diversity relative to the external magnetic field. Thus, the quadrupolar field will have greater change, leading to faster relaxation and shorter T2. Gp41_V2E mutant eliminates cell-cell fusion. Our CD spectroscopy studies show that the FPHM_V2E mutant is helical and the melting temperature is above 90 °C in 10mM Tris buffer + 0.2 % SDS at pH 7.4. Protein is trimer and induces no lipid mixing in PC: CHOL= 2:1 vesicles.
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Title: Allied studies on total sythesis of cyclic tripeptide TMC-95 via an iridium catalyzed borylation/deborylation strategy and teaching organic chemistry in "words"
Creator: Shen, Fangyi
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Arylboronate esters are versatile synthetic building blocks. Iridium catalyzed C-H activation/borylation reactions are a green way of making such building blocks as these reactions often obviate the need for prior functionalization (e.g. halogenation), the use of pyrophoric reagents, cryogenic conditions, etc. Installation of multiple boron substituents about the starting arene and then Ir catalyzed selective deborylation of the individual borons can allow for the formation of an even greater...
Show moreArylboronate esters are versatile synthetic building blocks. Iridium catalyzed C-H activation/borylation reactions are a green way of making such building blocks as these reactions often obviate the need for prior functionalization (e.g. halogenation), the use of pyrophoric reagents, cryogenic conditions, etc. Installation of multiple boron substituents about the starting arene and then Ir catalyzed selective deborylation of the individual borons can allow for the formation of an even greater diversity of borylated building blocks.The regioselectivity of Ir-catalyzed borylation is usually driven by sterics, however heterocycles are known to borylated at positions that exhibit heightened C-H acidity through the influence of the heteroatom. The regioselective borylation attained with a tryptophan derivative has been utilized in the development of a novel convergent route to the TMC-95 core. While pursuing a model synthesis of this natural product, the ability of bismuth salts to catalyze deborylations was discovered. These bismuth salts mediated methods can be highly selective in the in the deborylation of di and triborylated indoles. Furthermore, bismuths compounds are safe and less expensive as compared to the Ir-catalysts that facilitated deborylation. Numerous screening experiments on both substrates and other metal salts afforded a better understanding of how these novel deborylations can be applied in various synthetic settings and provided insight into possible mechanisms.Also, while I was a teaching assistant and a fixed-term instructor during my graduate studies at Michigan State University, I gradually realized that teaching is my passion and I am prepared to start my independent career and be an independent thinking teacher for the organic chemistry area.Owing to the nature of the subject, organic chemistry can be very visually distracting, and the image can be overpowering during student's learning. Like it or not students will try memorization first, our hypothesis is that once they know the "organic transformation formula" in words, via memorization or any other method, then introducing them to the structures of these functional groups will come with added context, and once they make that jump from word to structure they will be in a better position to understand reaction mechanisms. More importantly, understanding those reaction mechanisms will enable the student to progress to more complex topics.By introducing functional group transformations without the "clutter" of structures, we predict that once structures are introduced students will prioritize what's important because they will have trained their minds to ask what is the functional group, not "where did I see that structure in my notes".In short, we aim to train students to focus their attention on the reactive functional group of an organic molecule by emphasizing the use of WORDS to describe functional group transformation and teach the organic chemistry as the second language.
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Title: Determinants of eating behaviors of us army ROTC cadets in Midwestern universities
Creator: George, Beatriz G.
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Young adults 18-25 years of age, the largest demographic of the military, experience a high burden of obesity and eating disorders (ED) despite an emphasis on physical fitness, body composition, and operational readiness. Etiologic models for obesity and ED suggest body dissatisfaction (BD), dieting, negative affect (NA), and affect regulation represent potentially shared pathways. However, no studies have examined these factors and their shared pathways in military personnel, including ROTC...
Show moreYoung adults 18-25 years of age, the largest demographic of the military, experience a high burden of obesity and eating disorders (ED) despite an emphasis on physical fitness, body composition, and operational readiness. Etiologic models for obesity and ED suggest body dissatisfaction (BD), dieting, negative affect (NA), and affect regulation represent potentially shared pathways. However, no studies have examined these factors and their shared pathways in military personnel, including ROTC cadets. The overarching aim of this dissertation research was to investigate if ED symptoms were associated with body mass index (BMI), an indicator of obesity, and to describe potential correlates of their development. Three specific aims of this research focus on: 1) the prevalence and correlates of ED risk classification and symptoms in ROTC cadets, 2) the association between ED symptoms and BMI, and their potentially shared mechanisms, psychological inflexibility related to BD and dieting, and 3) the gaps in knowledge about eating behaviors and mediators of eating behaviors within the ROTC context and from perspective of ROTC cadets.In 2018, US Army ROTC cadets (n = 205) were recruited from two Midwestern universities and completed questionnaires about demographics, military-specific eating behaviors and mediators of eating behaviors, ED symptoms, and anthropometric measures. Chi-square, multivariable logistic regression, and multiple linear regression were performed in determining the rate of ED risk classification and correlates of ED risk classification and symptoms (Aim 1). Two measures of psychological inflexibility related to BD and dieting, in addition to the data for Aim 1, were used in mediation path analysis to examine the association of ED symptoms to BMI, and the indirect effects as mediated by psychological inflexibility related to BD and dieting (Aim 2). A purposively selected sample of eighteen cadets participated in one-on-one, semi-structured telephone interviews on eating behaviors and their mediators in the context of ROTC (Aim 3). Interviews were analyzed using thematic analysis to identify the most important themes and determinants related to eating behaviors in ROTC cadets.We found that ED symptoms and ED risk classification are prevalent in a sample of US Army ROTC cadets (10.1% of sample). Correlates associated with greater likelihood of ED risk classification and elevated ED symptoms were: sex, dieting, and military contextual factors such as attempting dieting and weight loss to meet body composition standards, and peers' comments on weight. Total ED symptoms scores were positively associated with BMI and partially mediated by psychological inflexibility related to BD and dieting. Cadets discussed perceived determinants of eating behaviors which included traditional determinants (e.g. time, money, nutrition knowledge) and ROTC-context specific determinants (e.g. preparation for body composition assessments and body image perceptions), which contributed to unhealthy weight control behaviors (dieting) and negative body image perceptions (BD) for some cadets. In conclusion, the prevalent correlates for eating disorder symptoms and risk in the sample of US Army ROTC cadets in this study were factors related to the enforcement of body composition standards and body image perceptions in the military context which may contribute to the development of dieting, BD, and NA. Longitudinal and/or intervention studies on this important topic may benefit our understanding of how ED symptoms and obesity develop over time and how targeting dieting, BD, NA, and affect regulation may be leveraged to mitigate ED and obesity to promote physical fitness, operational readiness and health in military personnel.
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Title: Linguistic strategies of entrepreneurial firms and financial resource acquisition
Creator: Pan, Lingling
Date: 2018
Collection: Electronic Theses & Dissertations
Description: "Resource acquisition from external investors is critical for the survival of entrepreneurial firms. Prior research indicated that an entrepreneurial firm's strategic use of language in public communication can enhance the firm's opportunity to obtain external funding. In this dissertation, I extend this line of research by focusing on the linguistic characteristics of an entrepreneurial firm's communication. Specifically, I focus on whether and how language vividness, a critical lexical...
Show more"Resource acquisition from external investors is critical for the survival of entrepreneurial firms. Prior research indicated that an entrepreneurial firm's strategic use of language in public communication can enhance the firm's opportunity to obtain external funding. In this dissertation, I extend this line of research by focusing on the linguistic characteristics of an entrepreneurial firm's communication. Specifically, I focus on whether and how language vividness, a critical lexical characteristic of an entrepreneurial firm's public communication, influences the firm's financial resource acquisition performance. Using entrepreneurial firms' IPO events as the study context, I examine the association between the level of language vividness of a firm's IPO prospectuses and its IPO performance. I argue that, in general, an entrepreneurial firm will have greater IPO success if its prospectus shows high usage of concrete and imagery words--the two primary dimensions of vivid language. Furthermore, I argue that the effects of vivid language are contingent on three factors: 1) the similarity of the language strategy the firm employs relative to the industry it is operating in; 2) the hotness of the IPO market the firm belongs; and 3) the specific content domain (section) in the IPO prospectus. Examining a sample of 679 IPO firms, I find that language concreteness and language imagery are positively associated with firm's IPO outcome. In addition, the hotness of IPO market that a firm belongs moderates the relationship between the firm's level of language imagery and IPO outcome."--Page ii.
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Title: Human in the loop : the role of individual and institutional behavior on predictive algorithms
Creator: Isaac, William
Date: 2018
Collection: Electronic Theses & Dissertations
Description: Over the past decade, algorithmic decision systems (ADS)--applications of statistical or computational techniques designed to assist human-decision making processes--have moved from an obscure domain of statistics and computer science into the mainstream. The rapid decline in the cost of computer processing and ubiquity of digital data storage has created a dramatic rise in the adoption of ADS using applied machine learning algorithms, transforming various sectors of society from digital...
Show moreOver the past decade, algorithmic decision systems (ADS)--applications of statistical or computational techniques designed to assist human-decision making processes--have moved from an obscure domain of statistics and computer science into the mainstream. The rapid decline in the cost of computer processing and ubiquity of digital data storage has created a dramatic rise in the adoption of ADS using applied machine learning algorithms, transforming various sectors of society from digital advertising to political campaigns, risk modeling for the banking sector, healthcare and beyond. Many agencies and practitioners in the public sector turn to ADS as a means to stretch limited public resources amidst growing public demands for equity and accountability. However, recent research from multiple fields has found that social and institutional biases, often reflected by input data used to generate predictions. The potential of perpetuated discrimination via input data is a particular concern in fields such as criminal justice where historical biases against minorities have the potential to exacerbate existing racial inequalities. In a series of three essays, this dissertation seeks to outline how institutional norms often shape algorithmic predictions, examine how ADSs alter the incentive structures for agents using the tools, and ultimately its impact on human decision-making.
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Title: Impacts of changing precipitation on nitrogen cycling in different landscape positions and cropping systems
Creator: Glanville, Kathryn
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Soil nitrogen (N) influences crop yields and can interact with climate change. Soil N has many transformations and transfers that are hard to quantify and control. These N transformations and transfers are mediated by many factors, including temperature, water, and carbon. Thus, impending climate change may strongly affect N cycling across cropping systems. To minimize N losses and increase crop production, we must maximize N use efficiency (NUE). Past research shows precipitation and soil...
Show moreSoil nitrogen (N) influences crop yields and can interact with climate change. Soil N has many transformations and transfers that are hard to quantify and control. These N transformations and transfers are mediated by many factors, including temperature, water, and carbon. Thus, impending climate change may strongly affect N cycling across cropping systems. To minimize N losses and increase crop production, we must maximize N use efficiency (NUE). Past research shows precipitation and soil moisture act as the primary physical drivers of terrestrial N cycling and losses. To improve NUE with changing precipitation patterns, controls on N cycling in terrestrial systems must be identified. Thus, experiments to elucidate the linkage between hydrological and biogeochemical controls are valuable (Chapter 1). Many aspects of the N cycle are influenced by a changing climate - two are especially important: nitrous oxide fluxes (N2O) and biological nitrogen fixation (BNF). N2O is a powerful greenhouse gas with over 250 times the radiative forcing of CO2. In Chapter 2, I test the hypothesis that changing rainfall patterns strongly alter N2O fluxes in agricultural soils as modulated by cropping system. I use rainfall manipulation shelters to expose soils to the same amount of rainfall delivered at different intervals (3-days, 14-days, and 28-days). Results from the 2016 and 2017 field seasons show cumulative N2O fluxes were 1.4 to 2 times higher when rainfall occurred in 28-day rather than shorter intervals in corn systems. Fluxes were related to changes in denitrifier enzyme activity for both years. In switchgrass systems N2O emissions were not significantly affected by rainfall intervals.In Chapter 3, I test the hypothesis that changing rainfall patterns that alter N2O fluxes will be modulated by landscape position as landscape position affects soil texture and carbon. Over two field seasons cumulative N2O fluxes were higher in toeslope positions than in summit positions, and longer rainfall intervals had higher fluxes in summits only, consistent with higher soil carbon and finer soil texture in toeslope positions. Knowledge of these landscape patterns deserve inclusion in models of current and future climate change effects in order to better quantify and mitigate agricultural N2O fluxes.In Chapter 4, I test the hypothesis that BNF is particularly vulnerable to changing rainfall patterns in till vs. no-till and in summit vs. toeslope positions due to differences in texture and organic matter. Results reinforce the importance of topographic position for predicting soybean BNF and show that summit positions are more sensitive to additional rainfall. Results also show changes in rainfall intensity affect BNF in tilled differently than in no-till soils. Models that incorporate these interactions will be better able to characterize legume crop performance and N fixation across landscapes and improve global estimates for BNF. Understanding these interactions in the agricultural US Midwest may help us improve sustainability of N use in cropping systems with a changing climate.
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Title: Weighting in multilevel models
Creator: Tong, Bing
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Large-scale survey programs usually use complex sampling designs such as unequal probabilities of selection, stratifications, and/or clustering to collect data to save time and money. This leads to the necessity to incorporate sampling weights into multilevel models in order to obtain accurate estimates and valid inferences. However, the weighted multilevel estimators have been lately developed and minimal guidance is left on how to use sampling weights in multilevel models and which...
Show moreLarge-scale survey programs usually use complex sampling designs such as unequal probabilities of selection, stratifications, and/or clustering to collect data to save time and money. This leads to the necessity to incorporate sampling weights into multilevel models in order to obtain accurate estimates and valid inferences. However, the weighted multilevel estimators have been lately developed and minimal guidance is left on how to use sampling weights in multilevel models and which estimator is most appropriate.The goal of this study is to examine the performance of multilevel pseudo maximum likelihood (MPML) estimation methods using different scaling techniques under the informative and non-informative condition in the context of a two-stage sampling design with unequal probabilities of selection. Monte Carlo simulation methods are used to evaluate the impact of three factors, including informativeness of the sampling design, intraclass correlation coefficient (ICC), and estimation methods. Simulation results indicate that including sampling weights in the model still produce biased estimates for the school-level variance. In general, the weighted methods outperform the unweighted method in estimating intercept and student-level variance while the unweighted method outperforms the weighted methods for school-level variance estimation in the informative condition. In general, the cluster scaling estimation method is recommended in the informative sampling design. Under the non-informative condition, the unweighted method can be considered a better choice than the weighted methods for all the parameter estimates. Besides, the ICC has obvious effects on school-level variance estimates in the informative condition, but in the noninformative condition, it also affects intercept estimates. An empirical study is included to illustrate the model.
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Title: Multi-scale approaches to global challenges in a telecoupled world
Creator: Xu, Zhenci
Date: 2019
Collection: Electronic Theses & Dissertations
Description: Global challenges such as water crisis, energy insecurity, biodiversity loss, land use change and climate change pose threats to the world's sustainability. Globalization enhances the connection of distant areas through various environmental and socioeconomic interactions. To solve the increasing challenges of achieving global sustainability in the context of globalization, the new telecoupling framework (socioeconomic and environmental interactions over distances) is proposed (Liu et al....
Show moreGlobal challenges such as water crisis, energy insecurity, biodiversity loss, land use change and climate change pose threats to the world's sustainability. Globalization enhances the connection of distant areas through various environmental and socioeconomic interactions. To solve the increasing challenges of achieving global sustainability in the context of globalization, the new telecoupling framework (socioeconomic and environmental interactions over distances) is proposed (Liu et al. 2013). A growing body of research has been exploring the dynamics, impacts, mechanisms, and structure of distant interactions involving global challenges. However, based on the telecoupling framework, we find no research that studies the evolution of multiple global environmental and socioeconomic interaction networks together. Also, the interactions between two kinds of distant virtual resource transfers simultaneously and the drivers of virtual resource transfers at the national scale are still unknown. Little research explores the evolution of virtual resource transfers at a national scale. The impacts of distant interactions on sending systems' sustainability at the regional scale has rarely been quantified and systematically analyzed. To address these knowledge gaps, I did the following work: First, I assessed the evolution of global telecouplings such as water, energy, land, CO2 emission, nitrogen emission and financial capital transfer networks and discussed how they have impacts on global water scarcity, energy crisis, land use change, global warming and nitrogen pollution. Second, I evaluated the interactions across two kinds of national telecouplings (interregional water and energy networks), and discussed their implications for the trading region's water scarcity and energy security, and explore the drivers of national telecouplings. Third, I studied the evolution of national virtual energy network. Fourth, I explored the water and food sustainability in a sending system of telecoupling (food transfer aimed at ensuring food security in the receiving system) at the regional scale. These four works have been accomplished in four chapters, respectively.Main findings from this dissertation include: At the global scale, the volumes of all these flows, except for land flow, increased over time. Financial capital flows increased most (188.9%), followed by flows of CO2 (59.3%), energy (58.1%), water (50.7%) and nitrogen (10.5%), while land transfer decreased by 8.8%. At the national scale using China as a demonstration, 40% of provinces gained one kind of resource (either water or energy) through trade at the expense of losing the other kind of internal resource (energy or water), and 20% of provinces suffered a double loss of both water and energy. The remaining provinces gained both water and energy. Over time, the total virtual energy transferred from energy-scarce to energy-abundant provinces increased from 43.2% to 47.5% from 2007 to 2012. At a regional scale, irrigated agriculture's annual water footprint in the North China Plain increased from 53 billion m3 in 1986 to 78 billion m3 in 2010. All counties faced unsustainable water use - local water consumption was greater than local renewable freshwater - even as the average crop water productivity increased from 0.90 kg.m-3 to 1.94 kg.m-3. These findings provide useful information for policy making to address environmental and socioeconomic challenges and build distant cooperation across multiple scales.
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Title: Essays in local public finance
Creator: Melnik, Walter Thomas
Date: 2018
Collection: Electronic Theses & Dissertations
Description: My dissertation studies how political factors, local labor demand shocks, and voting behavior affect state and local public goods provision. Following a brief introduction, I begin with “Legislative Redistricting, Party Politics, and the Spatial Distribution of Transportation Expenditure.” In this essay, I estimate how a state representative's political party affects road construction expenditure in areas that she represents. An extensive literature asks how a legislator's party affiliation...
Show moreMy dissertation studies how political factors, local labor demand shocks, and voting behavior affect state and local public goods provision. Following a brief introduction, I begin with “Legislative Redistricting, Party Politics, and the Spatial Distribution of Transportation Expenditure.” In this essay, I estimate how a state representative's political party affects road construction expenditure in areas that she represents. An extensive literature asks how a legislator's party affiliation affects public expenditure in the area the legislator represents. Unfortunately, almost all studies estimate this effect using party changes through election outcomes, which could be correlated with unobservable determinants of transportation expenditure. To overcome this issue, I identify my estimates using changes in party affiliation engendered by the 2012 state legislative redistricting in Ohio. In many cases, redistricting moved a geographic area into a district whose incumbent representative belonged to the opposing political party. This created variation in partisan alignment unrelated to election outcomes. From 2010-2017 the Republican party controlled the Ohio House of Representatives, the Ohio Senate, and the governorship. Using variation due to redistricting for identification, I find that areas moving from Republican to Democratic districts due to redistricting received $3.5 million (0.19 standard deviations) less annual highway construction funding than areas that remained in Republican districts. This funding decrease derives from a decline in the number of large construction projects in these areas. The estimated effects differ substantially when identified using variation through voting in non-redistricting years, perhaps due to selection issues concerning the type of districts changing parties through election outcomes. In addition, the expenditure change associated with a party change through election outcomes depends on whether the incumbent lost an election or retired, further evincing selection issues associated with this variation.In my next essay, “Municipal Government Reaction to Mass Layoffs in Ohio,” I study how municipal government finances respond to negative local employment shocks. Using data from 595 municipalities in Ohio, I estimate the change in municipal revenue after reported mass layoffs and plant closings, as well as the municipality's response: possible adjustments to tax rates, expenditure, and borrowing. I find that income tax revenue plummets in the year after a mass layoff, driven by a large decline in income tax base. Municipalities do not raise income or property tax rates to compensate for the income tax drop - rather, tax rates decline slightly. Property tax revenue also declines, while revenue from service charges and fees and intergovernmental revenue do not change significantly. Thus, total revenue drops substantially for several years after a mass layoff. In response, municipalities cut expenditure across several categories, including general government, public safety, leisure and community environment, and capital outlay. Cities also draw down their unreserved fund balance substantially, avoiding deeper cuts to expenditure by depleting their accumulated funds.In my last essay, “ Ballot Order and Ballot Roll-off: Evidence from Ohio,” coauthored with Mike Conlin and Paul Thompson, I study how an election item’s position on the ballot affects the probability that voters abstain from voting on that item (“roll-off”), and on the probability that voters choose to vote yes conditional on casting a ballot. Local tax referenda in Ohio rotate ballot position every year based on the level of local jurisdiction that placed the referendum on the ballot, providing a source of exogenous variation to test these propositions. Previous research suggests that voters are less likely to cast a vote for election items lower on the ballot, and more likely to choose the status quo. These findings support the idea of choice fatigue, suggesting that facing more decisions impairs voters’ decision making ability. Unlike previous papers, I am able to control for demographic characteristics (age and party affiliation) of voters who see each referendum. I find that voters tend to cast more yes votes for items lower on the ballot. I also find that older voters are much less likely, and partisan voters much more likely, to abstain from ballot items, showing the importance of controlling for these characteristics when estimating the effect of ballot position on roll-off.
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Title: DOWNLINK RESOURCE BLOCKS POSITIONING AND SCHEDULING IN LTE SYSTEMS EMPLOYING ADAPTIVE FRAMEWORKS
Creator: Abusaid, Osama M.
Date: 2018
Collection: Electronic Theses & Dissertations
Description: The present expansions in size and complexity of LTE networks is hindering their performance and their reliability. This hindrance is manifested in deteriorating performance in the User Equipment’s throughput and latency as a consequence to deteriorating the E-node B downlink throughput. This is leading to the need of smart E Node Base with various capabilities adapting to the changing communication environment. The proposed work aims at developing Self Organization (SO) techniques and...
Show moreThe present expansions in size and complexity of LTE networks is hindering their performance and their reliability. This hindrance is manifested in deteriorating performance in the User Equipment’s throughput and latency as a consequence to deteriorating the E-node B downlink throughput. This is leading to the need of smart E Node Base with various capabilities adapting to the changing communication environment. The proposed work aims at developing Self Organization (SO) techniques and frameworks for LTE networks at the Resource Blocks (RB) scheduling management level. After reviewing the existing literature on Self Organization techniques and scheduling strategies that have been recently implemented in other wireless networks, we identify several contrasting needs that can jointly be addressed. The deployment of the introduced algorithms in the communication network is expected to lead to improved and upgraded overall network performance. The main feature of the LTE networks family is the feed-back that the cell receives from the users. The feedback includes the down link channel assessment based on the User Equipment (UE) measure Channel Quality Indicator (CQI) in the last Transmission Time Interval (TTI). This feed-back should be the main decision factor in allocating Resource Blocks (RBs) among users. The challenge is how could one maps the users’ data onto the RBs based on the CQI. The Thesis advances two approaches towards that end:- the allocation among the current users for the next TTI should be mapped, consistent with historical feed-back CQI received from users over prior transmission durations. This approach also aims at offering a solution to the bottle-neck capacity issue in the scheduling of LTE networks. To that end, we present an implementation of a modified Self Organizing Map (SOM) algorithm for mapping incoming data into RBs. Such an implementation can handle the collective cell enabling our cell to become smarter. The criteria in measuring the E-node Base performance include throughput, fairness and the trade-off between these attributes.- Another promising and complementary approach is to tailor Recurrent Neural Networks (RNNs) to implement optimal dynamic mappings of the Resource Blocks (RBs) in response to the history sequence of the Channel Quality Indicator CQI feedback. RNNs can successfully build its own internal state over the entire training CQI sequence and consequently make the prediction more viable. With this dynamic mapping technique, the prediction will be more accurate to changing time-varying channel environments. Overall, the collective cell management would become more intelligent and would be adaptable to changing environments. Consequently, a significant performance improvement can be achieved at lower cost. Moreover, a general tunability of the scheduling system becomes possible which would incorporate a trade-off between system complexity and QoS.
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Title: Use of administative claims data to design and emulate a clinical trial in acute stroke patients comparing rehabilitation at inpatient rehabilitation facilities to skilled nursing facilities
Creator: Simmonds, Kent P.
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Stroke affects nearly 800,000 people every year in the United States and is a leading cause of adult disability. After hospitalization half of stroke patients continue to require medical and rehabilitation services provided at inpatient rehabilitation facilities (IRFs) or skilled nursing facilities (SNFs). In general, IRFs provide time-intensive therapy for two to three weeks, while SNFs provide moderately intensive therapy for four- to five-weeks. There is substantial variation in the...
Show moreStroke affects nearly 800,000 people every year in the United States and is a leading cause of adult disability. After hospitalization half of stroke patients continue to require medical and rehabilitation services provided at inpatient rehabilitation facilities (IRFs) or skilled nursing facilities (SNFs). In general, IRFs provide time-intensive therapy for two to three weeks, while SNFs provide moderately intensive therapy for four- to five-weeks. There is substantial variation in the utilization of these alternative rehabilitation settings, but their relative comparative effectiveness remains uncertain. A randomized controlled trial (RCT) would provide an unbiased comparative effectiveness estimate, but the design of such a trial is complicated by several practical and ethical issues. The overarching purpose of this dissertation was to use Medicare claims data to inform the design and to emulate such a trial. In the first aim, we sought to identify patient and hospital level factors that were associated with IRF or SNF discharge and characterize the heterogeneity of hospital effects that influenced discharge to an IRF (vs. SNF). From a retrospective cohort of 145,894 stroke patients, we used multi-level multivariable models to identify several patient- and hospital- level factors that were independently associated with discharge setting. We also showed that hospitals contributed around a third of the variation in IRF (vs. SNF) discharge, but there was substantial variation in the effect that specific hospitals had on influencing IRF discharge. The second aim, was to identify a target trial population that optimized the explanatory-pragmatic balance of a subsequent RCT. To identify this population, we profiled hospitals based on their propensity to discharge stroke patients to IRFs (vs. SNFs) and inferred IRF and SNF referral networks for each hospital. The final target trial population included 44,950 patients (30.8% of the starting sample) who were treated at 441 hospitals (14.5%) and subsequently discharged to 745 IRFs (64.8%) and 5,974 SNFs (48.2%).The third aim was to emulate three alternate RCTs that compared patient outcomes at IRFs vs. SNFs. Trial #1 used the target trial population identified in Aim 2, while trials #2 and 3 excluded increasingly infrequently used IRFs and SNFs. Comparative effectiveness was estimated using a matched propensity score analysis. Overall, on a relative basis, patients treated at IRFs were between 18-35% more likely to be successfully discharged home (i.e., alive and at home for >30 days) and were between 11-15% less likely to die within one year of acute care discharge. The variation in the effect size estimates across the trials was driven by poorer outcomes among patients treated at infrequently used SNFs. Finally, we identified that a moderate sized unmeasured confounder would nullify the observed differences.In conclusion, we identified that referring hospitals are a major driver of IRF or SNF use, and that patients treated at IRFs had better outcomes (relative to SNF patients). However, our results were limited by the inability to adjust for potentially important unmeasured confounders. A pragmatic RCT would eliminate such biases and provide a more valid comparative effectiveness estimate of these two alternative rehabilitation settings.
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Title: Physics-based crystal plasticity modeling of single crystal niobium
Creator: Maiti, Tias
Date: 2017
Collection: Electronic Theses & Dissertations
Description: Crystal plasticity models based on thermally activated dislocationkinetics has been successful in predicting the deformation behavior ofcrystalline materials, particularly in face-centered cubic (fcc) metals.In body-centered cubic (bcc) metals success has been limited owing toill-defined slip planes. The flow stress of a bcc metal is stronglydependent on temperature and orientation due to the non-planar splittingof a/2<111> screw dislocations. As a consequence of this, bccmetals show two...
Show moreCrystal plasticity models based on thermally activated dislocationkinetics has been successful in predicting the deformation behavior ofcrystalline materials, particularly in face-centered cubic (fcc) metals.In body-centered cubic (bcc) metals success has been limited owing toill-defined slip planes. The flow stress of a bcc metal is stronglydependent on temperature and orientation due to the non-planar splittingof a/2<111> screw dislocations. As a consequence of this, bccmetals show two unique deformation characteristics: (a) thermally-activated glide of screw dislocations - the motion of screwcomponents with their non-planar core structure at the atomistic leveloccurs even at low stress through the nucleation (assisted by thermalactivation) and lateral propagation of dislocation kink pairs; (b)break-down of the Schmid Law, where dislocation slip is driven only bythe resolved shear stress.Since the split dislocation core has to constrict for a kink pairformation (and propagation), the non-planarity of bcc screw dislocationcores entails an influence of (shear) stress components acting on planesother than the primary glide plane on their mobility. Anotherconsequence of the asymmetric core splitting on the glide plane is adirection-sensitive slip resistance, which is termed twinning/atwinningsense of shear and should be taken into account when developingconstitutive models.Modeling thermally-activated flow including the above-mentionednon-Schmid effects in bcc metals has been the subject of much work,starting in the 1980s and gaining increased interest in recent times.The majority of these works focus on single crystal deformation ofcommonly used metals such as Iron (Fe), Molybdenum (Mo), and Tungsten(W), while very few published studies address deformation behavior inNiobium (Nb). Most of the work on Nb revolves around fitting parametersof phenomenological descriptions, which do not capture adequately themacroscopic multi-stage hardening behavior and evolution ofcrystallographic texture from a physical point of view. Therefore, weaim to develop a physics-based crystal plasticity model that can capturethese effects as a function of grain orientations, microstructureparameters, and temperature.To achieve this goal, first, a new dilatational constitutive model isdeveloped for simulating the deformation of non-compact geometries (foamsor geometries with free surfaces) using the spectral method. The modelhas been used to mimic the void-growth behavior of a biaxially loadedplate with a circular inclusion. The results show that the proposedformulation provides a much better description of void-like behaviorcompared to the pure elastic behavior of voids. Using the developeddilatational framework, periodic boundary conditions arising from thespectral solver has been relaxed to study the tensile deformationbehavior of dogbone-shaped Nb single crystals.Second, a dislocation density-based constitutive model with storage andrecovery laws derived from Discrete Dislocation Dynamics (DDD) isimplemented to model multi-stage strain hardening. The influence ofpre-deformed dislocation content, dislocation interaction strengths andmean free path on stage II hardening is then simulated and compared within-situ tensile experiments.
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Title: Preservice teachers' intention to teach media and information literacy in their future classroom : an application of the theory of planned behavior
Creator: Gretter, Sarah
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "This dissertation is a multi-phase study looking at preservice teachers' intention to teach Media & Information Literacy in their future classroom. Each of the three studies presented in this dissertation answered a specific question: 1) What do preservice teachers think about teaching MIL? 2) What predicts preservice teachers' intention to teach MIL? and 3) How can we support preservice teachers' intention to teach MIL? The first paper in this dissertation reported on an elicitation study...
Show more"This dissertation is a multi-phase study looking at preservice teachers' intention to teach Media & Information Literacy in their future classroom. Each of the three studies presented in this dissertation answered a specific question: 1) What do preservice teachers think about teaching MIL? 2) What predicts preservice teachers' intention to teach MIL? and 3) How can we support preservice teachers' intention to teach MIL? The first paper in this dissertation reported on an elicitation study conducted with focus groups of preservice teachers to understand, from their perspectives, the factors that would either impede or facilitate the teaching of MIL in their future classroom. The second paper described the design, validation, and results of a survey based on these factors. The third paper reported on an online module with reflective exercises designed around the results gathered in the aforementioned survey. Each paper describes the findings that emerged from its study, followed by implications for research and practice, along with questions for the field of Media & Information Literacy education"--Page ii.
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Title: Where the rivers come together : reclaiming and re-imagining indigenous history, identity, and language in the city
Creator: Haviland, Adam
Date: 2017
Collection: Electronic Theses & Dissertations
Description: The movement and migration of Native Americans to urban areas is usually traced to the urbanization programs of the 1950s and 1960s. However, the recent scholarship of Coll Thrush (2007) and John Low (2016) highlight the long history of urban spaces as Indigenous spaces and the role Indigenous people and communities have played in their growth and development. Similarly, the discourse of language loss and revitalization, urban spaces, and Indigenous urban communities are seen as places or...
Show moreThe movement and migration of Native Americans to urban areas is usually traced to the urbanization programs of the 1950s and 1960s. However, the recent scholarship of Coll Thrush (2007) and John Low (2016) highlight the long history of urban spaces as Indigenous spaces and the role Indigenous people and communities have played in their growth and development. Similarly, the discourse of language loss and revitalization, urban spaces, and Indigenous urban communities are seen as places or endpoints of assimilation. Thus, language revitalization efforts and programs often focus on reservations as the primary domains where Indigenous languages and their speakers persist and thrive. Yet, despite settler colonial narratives of vanishing that erase Indigenous people and Indigenous languages from urban areas, cities have, and continue to be, important intersections of movement and migration and with deep historical roots where Indigenous languages persist and thrive as ideological markers of identity, belonging, and as spoken languages.This Research shows how Lansing, Michigan, Nkwejong (the place where the rivers come together) has a long history as an Indigenous intersection and space that challenges the local settler-colonial narratives of removal and erasure. Lansing has remained an Indigenous space through traditions of movement and migration that were driven by the auto industry and educational opportunities. Through these movements, Anishinabek from reservations in and around Manitoulin Island came here in the 1960s and 1970s who were fluent speakers ofAnishinaabemowin. Anishinabek from Canada and local Anishinabek, who had lost the language, created community and belonging through educational programs. These spaces have become focal points where community comes together and, for many individuals, are the primary spaces where language, culture, and identity are reclaimed and passed on. However, these are also spaces of tension where gender roles, language ideologies, and linguistic practices concerning language as an ideological marker of identity and its role as a communicative system are challenged and reimagined.Through interviews with community members and participant observation, I explore relationships to urban and reservation “homelands,” the importance of education as places where individuals develop relationships to their identities and culture, and the role that language, as both an ideological marker of identity and belonging and as a communicative system, play in their everyday lives and experiences. While most participants agreed that language was important to preserving identity and traditional knowledge, their relationships with their identities as urban and Indigenous, and their relationships to Indigenous language, highlight: (1) the need to reexamine language ideologies that link Language to “traditional culture and Knowledge” and the impacts these ideologies have on language revitalization. (2) The importance of urban areas as Indigenous homelands and places where Indigenous languages persist, and (3) the role of education as intersections and places of tension where multiple ideologies, identities, and ways of being Indigenous are expressed and reimagined.
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Title: Feasibility and application of a CuxO-based memristor for sensing oxygen and other gases
Creator: Nyenke, Chinwe Pamela
Date: 2017
Collection: Electronic Theses & Dissertations
Description: This dissertation introduces the design, fabrication, and application of acopper-oxide-based memristor for the passive sensing of oxygen and other gases.The device design was as follows: Deposition of copper (Cu) bottom electrodes,(oxygen) vacancy-rich copper oxide (CuxO) switching layers, and tungsten (W) topelectrodes in a crossbar array structure. The CuxO layer was deposited via reactivesputtering of a Cu target with an argon-oxygen (Ar/O2) mixture. A portion of thislayer was extended...
Show moreThis dissertation introduces the design, fabrication, and application of acopper-oxide-based memristor for the passive sensing of oxygen and other gases.The device design was as follows: Deposition of copper (Cu) bottom electrodes,(oxygen) vacancy-rich copper oxide (CuxO) switching layers, and tungsten (W) topelectrodes in a crossbar array structure. The CuxO layer was deposited via reactivesputtering of a Cu target with an argon-oxygen (Ar/O2) mixture. A portion of thislayer was extended from each array cell to be exposed for sensing. Memristivedevices of different switching layer thicknesses were initially explored forirreversible sensing of oxygen in ambient air. Results of this first experimentdemonstrated an increase in resistance states upon prolonged exposure toambient air. For the second experiment, memristive devices were fabricated withsub-micron holes that were etched into the W top electrode to better reveal theswitching layer surface. The devices were also subjected to ambient oxygen at 180deg C to induce passive sensing in minutes. Resistance results were consistentwith the first experiment but also revealed a dependence on the surface area ofthe exposed oxide. Finally, memristive devices were investigated in a thirdexperiment for reversible sensing of an oxidizing gas and reducing gas at roomtemperature. This time, changes were not only observed in resistance but also inhysteresis (current versus voltage) depending on the type of gas introduced.Overall, this work demonstrates a step towards the use of the memristor as a gassensor, which we have named “memsensors”, by taking advantage of the device’sability to memorize (or record) historical information.
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