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CUTICULAR HYDROCARBONS AND ECOLOGICAL SPECIATION IN DROSOPHILA LUMMEI
Get PDFThesis (M.S.)--Michigan State University. Entomology - Master of Science, 2025Ecological speciation occurs when populations diverge due to adaptation to different environmental conditions, leading to reproductive isolation. Cuticular hydrocarbons (CHCs) serve dual roles in desiccation resistance and mate choice, making them key traits to investigate in ecological divergence. This thesis examines CHC variation between two populations of Drosophila lummei from Japan and Russia to investigate their role in ecological speciation. Our results showed significant differences in CHC composition between the populations, with Japan exhibiting a greater diversity of CHCs. Desiccation resistance assays showed that the Japan population had higher desiccation resistance compared to the Russia population. However, reciprocal crosses between these populations did not show any significant differences in desiccation resistance, suggesting that the genetic factors effecting desiccation resistance is not sex-linked. Male mate choice assays showed no preference for females of either population, suggesting that CHCs may not influence male mate choice in this species. Additionally, reproductive assays showed that offsprings counts varied across temperature conditions, with Russia D. lummei producing fewer offspring than Japan D. lummei and hybrid crosses. These findings suggest that the CHC variation in D. lummei may be shaped by ecological factors but do not affect mate choice based on our limited experiments. Future research will include incorporating female choice experiments and transcriptomic analyses to determine whether CHC variation in this species affects female choice and the genetic basis underlying this variation. This study provides valuable insights into how environmental pressures may drive divergence in mating traits, contributing to our broader understanding of speciation mechanisms in Drosophila.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
COMPOSTABLE AND RECYCLABLE PAPER PACKAGING USING MODIFIED SOYBEAN OIL COATING WITH EXCELLENT WATER- AND OIL-RESISTANT PROPERTIES
Get PDFThesis (Ph.D.)--Michigan State University. Chemistry - Doctor of Philosophy, 2025Originating from plants as a natural, renewable resource, paper-based materials have garnered significant interest in recent years across packaging and non-packaging sectors. However, the utility of paper-based packaging remains limited due to its porous nature and the presence of hydroxyl (-OH) groups, which confer hydrophilic characteristics. This makes it susceptible to the permeation of liquids and gases through cellulose fibers, leading to rapid deterioration of its barrier and mechanical properties.To address these shortcomings and promote broader adoption of paper-based packaging in daily life, various coating materials have been developed and applied to paper surfaces. For instance, PFAS (per- and polyfluoroalkyl substances, also known as "forever chemicals") and synthetic polymers like polyethylene (PE) and polypropylene (PP) have been widely used. However, these fluorinated chemicals are toxic, and plastic-based packaging presents additional challenges, such as low recycling rates (currently 100 years), and microplastic contamination of landfills and water bodies. This PhD thesis explores the potential of sustainable, plant-based soybean oil as a source for paper coatings, offering a greener alternative to develop recyclable, repulpable, and biodegradable paper packaging materials with enhanced water and oil resistance properties. The first section of the thesis highlights the use of acrylated epoxidized soybean oil (AESO) for paper coating applications. AESO coatings achieved exceptional oil and water resistance, as evidenced by a perfect kit rating (12/12) and a Cobb1800 value (~2 g/m2). The coating process involved applying AESO with 2 wt% of a photoinitiator (2-hydroxy-2-methylpropiophenone) using a doctor blade, followed by UV curing to form a highly crosslinked polymeric surface. Notably, this study is the first to demonstrate pure AESO's potential in paper coating with extended water resistance testing of 30 minutes, significantly surpassing the previous benchmark of 60 seconds. The second section focuses on optimizing a waterborne coating system using an AESO blend with biocompatible polyvinyl alcohol (PVOH) as an emulsifying agent. PVOH, approved for direct food contact, provides a sustainable approach to emulsifying AESO. The AESO emulsion was applied to kraft paper, UV-cured, and achieved excellent oil and water repellency, with Cobb600 and Cobb1800 values of ~9 and ~13 g/m2, respectively, and a kit rating of 7/12. Optimization of AESO loading revealed that the best-performing sample had a loading range of ~15\u201320 g/m2. The coated paper retained over 90% of its mechanical properties and demonstrated more than 90% biodegradation within 90 days under industrial conditions. The third section investigates the incorporation of magnesium hydroxide nanoparticles (Mg(OH)2 NPs) into the waterborne AESO system to impart antimicrobial properties for potential applications in food and medical packaging. The Mg(OH)2 dispersion in the AESO emulsion produced coatings with robust water and oil resistance. Tests revealed excellent moisture and oxygen barrier performance (in thin films of cured AESO) and a ~4 log reduction in E. coli populations, achieving 99.99% bacterial elimination. These properties make the coated paper highly suitable for food and medical packaging applications. The fourth section examines the integration of degradable crosslinkers into soybean oil to enhance the recyclability of coated paper. A photocurable AESO emulsion was blended with oligoacrylate lactide/glycolide to improve recyclability. In parallel, epoxidized soybean oil (ESO) was modified with glycolic and methacrylic groups. Hexagonal boron nitride (H-BN) nanosheets were employed as emulsifiers to stabilize these blends. The coated paper underwent extensive water and oil resistance tests, with its repulpability and recyclability successfully validated. Vermicomposting tests confirmed the compostability of the coated paper, presenting a sustainable alternative to conventional PFAS-coated packaging materials.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
Surveillance Capitalism, Neuroeconomics, and the User Experience : Charting Intersections
Get PDFThesis (M.A.)--Michigan State University. Rhetoric and Writing \u2013 Master of Arts, 2025This thesis uses a case study of Spotify Wrapped\u2014a year-in-review (YIR) feature of the Spotify app made possible by the data Spotify passively collects from its users\u2014to explore how surveillance capitalism, social psychology, neuroeconomics, and user-centered UX research and design intersect, overlap, and converge to create complex situations the modern consumer must now navigate. Informed by scholarship, methods, and frameworks from multiple disciplines, I designed and distributed a 20-question survey to a variety of participant demographic groups, the data from which I describe, analyze, discuss, and contextualize in this thesis. Throughout this process, one core point of inquiry guided my efforts: why do self-identified surveillance-opposed consumers actively and knowingly engage with products and services fueled by surveillance capitalism? Preliminary findings based on an application of neuroeconomics\u2019 value-based decision-making framework reveal that consumers often value most other things\u2014such as building social capital, ensuring social inclusion, and satisfying their curiosity about their music streaming habits\u2014more than they value protecting their personal data and digital privacy. Results and their implications suggest a need for additional research that further examines situational complexities identified in this research and explores ways in which UX designers can build experiences that encourage users to protect themselves from surveillance capitalism.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
Silvicultural Strategies for Promoting Resilient Tree Regeneration in Managed Northern Hardwood Forests, Michigan, USA
Get PDFThesis (Ph.D.)--Michigan State University. Forestry - Doctor of Philosophy, 2025Northern hardwood forests (NHF) of the upper Great Lakes region have undergone a century of structural simplification and compositional homogenization due to exploitative logging of old-growth stands and the ubiquitous application of selection silviculture in second-growth stands. Contemporary partial harvests often fail to regenerate well-stocked, species-diverse regeneration layers, a pattern attributed to low light availability and deer browsing, among many other limiting factors. This dissertation investigates silvicultural strategies for promoting well-stocked, diverse tree regeneration in managed NHF of northern Michigan, USA, as these conditions are likely to strengthen NHF resilience to future disturbances.Chapter 2 examines six-year diversity and stocking outcomes following a harvest intensity gradient representing four silvicultural systems: single-tree/small group selection, shelterwood, large group selection, and seed tree. Across 72 stands, species diversity and stocking of a species group desirable for biomass productivity objectives increased with harvest intensity, mainly through the addition of shade-intolerant species. However, a group of largely shade-tolerant and midtolerant species desired for NHF wood economics objectives was less responsive to harvest intensity. Stocking of these groups also exhibited marked regional variation, suggesting that harvest intensity alone does not fully determine early regeneration outcomes. In Chapter 3, individual species analyses revealed stocking of shade-intolerant species was associated with increased harvest intensity, whereas shade-tolerant and midtolerant species were best predicted by advance regeneration and pre-harvest canopy tree density, suggesting pre-harvest stand structure is critical for many important NHF species. As browsing pressure increased, some browsing-preferred species exhibited slightly reduced stocking, while stocking of prominent browsing-resilient or avoided species increased modestly; deer browsing likely exerts its greatest influence on regeneration outcomes by shaping the structure and composition of advance regeneration in the decades preceding harvest, rather than in the years that follow. Given the importance of advance regeneration for many NHF species, Chapter 4 examines regeneration dynamics by relating sugar maple (Acer saccharum) seedling density to the diameter and density of local seed sources. Seedling counts were most strongly predicted by the density of sugar maple stems > 40 cm dbh within 35 \u2013 40 m. Applying this relationship to a state resource-wide dataset of 126 managed NHF stands revealed that many stands lack sufficient densities of these large-diameter seed sources, which could constrain the establishment of dense advance regeneration layers, suggesting a need to revise residual stand targets. Chapter 5 investigates direct seeding as a method to augment regeneration diversity. Ten native or assisted migration candidate species were sown across a gradient of harvest intensity in plots that were either accessible or inaccessible to seed predators. Establishment was highest for large-seeded species that were buried, and was not influenced by harvest intensity. In contrast, small-seeded, broadcast-sown species exhibited lower and more variable establishment, especially following high-intensity harvests. Although seed predation reduced establishment across all treatments, it was not severe in most stands, suggesting that direct seeding may be a viable strategy for increasing diversity in NHF regeneration layers. Together, these findings suggest that silvicultural practices such as increased harvest intensity, large-diameter seed source retention, and artificial regeneration practices such as direct seeding are likely to foster more diverse and resilient regeneration layers in managed northern hardwood forests of the upper Great Lakes region.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
MARITAL METRICS : USER AGENCY AND CONSTRUCTION IN EARLY AMERICAN MARRIAGE COMPATIBILITY SURVEYS
Get PDFThesis (M.A.)--Michigan State University. Rhetoric and Writing \u2013 Master of Arts, 2025This thesis looks at 20th century American marriage counseling compatibility surveys to argue that surveys\u2014as a form of technical communication\u2014have historically made assumptions about users\u2019 gender, race, ability, and religious identities, which in turn, have had material effects on users\u2019 lives. I am specifically interested in the way that the scientific, quantitative, and (more broadly) positivistic underpinnings of these surveys shaped how participants could answer survey questions. I use conventional content analysis to read three historical compatibility surveys to demonstrate the need for technical communicators to attend to the ways in which their writing and design choices might perpetuate notions of a \u201cnormative\u201d user.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
ENTANGLED IDENTITY AND PLACEMAKING WITH THE OKLAHOMA RIVER : MAPPING BLACK ENVIRONMENTAL UN/BELONGING IN OKLAHOMA CITY
Get PDFThesis (M.A.)--Michigan State University. Rhetoric and Writing \u2013 Master of Arts, 2025Our ongoing climate crisis impacts every aspect of our existence, seen and unseen. It is critical, in efforts to work toward environmentally- and climatically-just futures, to critically engage with the stories and powers that have enabled injustice and unbelonging. In the United States, this is particularly relevant for Black Americans, who have both generationally inherited environmental exclusion and who advocate for environmental resilience and community-building. This project, heavily informed by Black and Indigenous American environmental scholarship, aims to demonstrate how environmental epistemologies in placemaking influence Black communities\u2019 internalization of unbelonging that is also manifested among nonhuman community members \u2013 specifically, rivers. Homing in on my hometown of Oklahoma City, Oklahoma, I draw on placemaking policy and strategies from the City of Oklahoma City to uncover settler colonial rhetoric within river infrastructure planning that parallel Black environmental restrictions that have sought to erase the identities within Black environmental belonging and the Oklahoma River. The motivation for this erasure, as evident through rhetorical analyses of river infrastructure policy documents; placemaking; and mapping practices, is revealed in its commodification for economic growth and glory for the City. Though these efforts commodify, displace, and systematically oppress Black identities, community coalition-building in Oklahoma City\u2019s Eastside neighborhood demonstrates hopeful and resilient environmental and climatic futures. Oklahoma City\u2019s comprehensive policy plan, planokc, offers an entry point through its supplemental adaptokc plan for such environmental coalition-building and recognition to be forefronted in future Oklahoma City placemaking policies and strategies. Through adaptokc \u2013 as a living document that recognizes the exigence of environmental care and awareness \u2013 Oklahoma City placemaking has the potential to, in the face of this climate crisis, build and set an example of co-led futures in which Black and nonhuman, environmental belonging are woven into the fabrics of \u201cplace.\u201dDescription based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
Essays on Impacts of Artificial Intelligence on Labor Market Outcomes and Educational Choices
Get PDFThesis (Ph.D.)--Michigan State University. Economics - Doctor of Philosophy, 2025This dissertation examines impacts of Artificial Intelligence (AI) on labor market outcomes and educational choices. The first chapter focuses on labor supply by exploring the relationship between the growth of AI and college major choices. The second chapter turns to labor demand, studying the impacts of AI job postings on labor market outcomes of heterogeneous skill groups. The last chapter analyzes how AI adoption in firms affects gender wage gaps.The first chapter explores how the rise in AI shapes college major choice. I propose a new method to measure how well a major prepares students to work with AI by matching phrases for AI subfields with college major descriptions. I then define AI skill-related majors as those that provide AI-related skill training. Those majors that are most complementary to AI have systematically high growth rates of bachelor\u2019s degree conferrals from 1990 to 2019. In contrast, I find evidence suggesting that majors that are most exposed to AI-driven substitution grow relatively slowly, especially at elite universities.In the second chapter, I study effects of AI on employment and wages for heterogeneous skill groups in the U.S. by introducing and analyzing a task-based framework. I first categorize labor into four skill groups based on skill specializations: (1) abstract and AI-intensive; (2) abstract-intensive but not yet AI-related; (3) routine-intensive; and (4) manual-intensive. The demand for AI skills is then measured by matching phrases for AI-developing skills to descriptions of online job postings. I document a consistent upward trend in the share of AI postings for the high-skilled AI-complement group during my sampling period, 2012-21. There is a strong growth in both employment and wages for abstract and AI-intensive occupations associated with an increasing demand for AI skills, while abstract but not-yet-AI occupations have much smaller growth. Middle-skilled occupations experience wage declines associated with an increase in the standard deviation of the intensity that AI-developing skills are required for job tasks. Employment and wage gaps between abstract and AI-intensive occupations and other skill groups widen as the labor market favors workers with AI skills, consistent with my theoretical model's implications. I also discuss whether AI is possibly a general-purpose technology.The last chapter analyzes the link between gender wage gaps and AI adoption. Using a real-time, high-frequency data on AI adoption in business, I construct measures for current, expected, and continuing AI adoption. AI adoption at the state-month level narrows within-occupation gender wage gaps in mean hourly wages, whereas AI adoption at the industry-month level exhibits a non-monotonic pattern in within-industry, between-occupation gender wage gaps across different percentiles of the wage distribution. The gap widens at the 10th percentile and the median, but shrinks at the 90th percentile. However, using data on online job postings that require AI skills, I find that a higher share of AI postings benefits women more than men across the wage distribution.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
THE EFFECTIVENESS OF THE MODIFIED "THREE GOOD THINGS" INTERVENTION ON WELL-BEING FOR COLLEGE STUDENTS WITH AND WITHOUT DISABILITY
Get PDFThesis (Ph.D.)--Michigan State University. Counselor Education and Supervision - Doctor of Philosophy, 2025This study examined the feasibility and effectiveness of a modified Three Good Things gratitude intervention in promoting well-being among college students with and without disabilities. Using a randomized controlled design, participants completed pre-, post-, and one-month follow-up assessments. Results from Repeated Measure Analysis of Variance revealed statistically significant improvements in well-being, resilience, and perceived stress, with differential effects across time and groups. Several elements of the PERMA model\u2014particularly Positive Emotions, Relationships, Meaning, and Accomplishment\u2014demonstrated notable change, especially with time-by-group interactions. Both students with and without disability demonstrated benefit from participating in the study. Qualitative data from participants\u2019 daily reflections and open-ended feedback provided further insight into the perceived benefits, engagement patterns, and areas of personal growth associated with the intervention. The daily reflections illustrated the positive impact of the intervention to establish lasting changes in participants\u2019 personal growth and academic success, especially when participants integrated the practice into daily routines. The study also demonstrated high feasibility through digital delivery, structured reminders, and supportive communication. Findings have implications for counseling, higher education, and future research on accessible and inclusive gratitude interventions.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
REPRESENTING \u201cWORLD-CLASS\u201d UNIVERSITIES : TOP CHINESE UNIVERSITIES\u2019 DIGITAL DIPLOMACY ON X/TWITTER
No full textThesis (Ph.D.)--Michigan State University. Higher, Adult, and Lifelong Education - Doctor of Philosophy, 2025In an era where social media plays an increasingly important role in global communication, universities worldwide actively use various platforms to increase their visibility, shape their institutional identities and engage with international audiences. While extensive research has examined how universities in the West utilize social media for branding and engagement, less attention has been given to how universities in non-Western contexts navigate these digital spaces. In this dissertation, I examined how top Chinese universities represented themselves on X (formerly known as Twitter). Despite the platform\u2019s inaccessibility within China, these universities strategically use it to engage global audiences and construct their institutional prestige. In my analysis, I focused on four leading C9 League universities, namely Peking University, Tsinghua University, Shanghai Jiao Tong University, and Zhejiang University, and investigated how they employ social media to construct their global image through their social media representations.To conduct this study, I employed multimodal discourse analysis, drawing on Stuart Hall\u2019s (1997) theory of representation, Fairclough\u2019s (1995) critical discourse analysis (CDA), Kress and van Leeuwen\u2019s (2006) visual grammar, and Heinrich\u2019s (2017) photographic techniques. This framework allowed me to examine the interplay between text, imagery, and composition in the social media posts and to unpack the ideological dimensions embedded in these representations. Through this framework, I explored how these universities strategically constructed narratives of global excellence across three key themes: research excellence, student engagement in China\u2019s cultural diplomacy, and global partnerships. My findings revealed how social media representations reinforced discourses about Chinese higher education\u2019s aspirations for world-class status, its role in China\u2019s soft power strategy, and its efforts toward internationalization. In this dissertation, I mainly argue that through multimodal representations on X/Twitter, top Chinese universities actively construct and reinforce the idea of the \u201cworld-class university\u201d by foregrounding research excellence, student engagement in cultural diplomacy, and global partnerships. They use digital diplomacy as a tool for promoting international engagement, enhancing institutional prestige, and exercising China\u2019s soft power. The findings of my study contribute to a comprehensive understanding of the complex interplay between media, education, and geopolitics in the representation of Chinese universities. My dissertation advances scholarship in higher education studies and cultural studies by offering insights into the strategic use of social media for institutional representation within a globally competitive landscape. It also calls for a more critical and pluralistic reimagining of what it means to be a world-class university, challenging Western-dominated paradigms and advocating for more contextually diverse definitions of excellence in the context of global higher education.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
AN INVESTIGATION OF TWO BIOLOGICAL SOURCES CONTRIBUTING TO SIGNAL LOSS IN THE IMPLANTED BRAIN
Get PDFThesis (Ph.D.)--Michigan State University. Neuroscience - Doctor of Philosophy, 2025Implantable electrodes have gained popular attention in research and clinical settings to treat and study a variety of neurological conditions. Detection of electrical and chemical signals drive the performance of implanted microelectrodes used for sensing and/or stimulating brain activity. However, signal instability and device failure over time in the implanted brain inhibit the therapeutic and biomedical promise of such microelectrodes. As the field of neurotechnology moves towards next-generation probes and sophisticated methodologies to improve signal detection in the brain, detailed explorations of the inherent biological response to implanted electrodes are warranted. The foreign body reaction to implanted probes can change over acute and chronic durations while experiencing structural, functional and genetic changes at the tissue level. Further, mechanical factors (for example, device material, flexibility, dimensions, etc.) can exacerbate or mitigate the inflammatory response, signal detection and overall integration of the device-tissue interface. This dissertation recognizes the diverse nature of the tissue response to implanted microelectrodes and conducts a deeper investigation of two biological sources contributing to signal loss \u2013 (1) protein adsorption, or biofouling, and (2) cellular encapsulation. The findings expand on \u2013 (1) assessments of a novel all-diamond boron-doped diamond microelectrode to tackle signal instability influenced by protein adsorption, and (2) gene expression changes brought about by cellular encapsulation of implanted devices. The results discussed herein take an interdisciplinary approach to investigate the biological sources influencing signal detection and employ numerous techniques including fast-scan cyclic voltammetry, electrophysiology and spatial transcriptomics. Overall, this work adds to the growing body of literature reporting on the basic science understanding of the multifaceted biological response to implantable microelectrodes.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references