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Welcome to the University Archives electronic records community. The University Archives community in Scholars’ Bank is for university records in digital form. The material contained in Scholars’ Bank represents a small portion of the institutional records housed in University Archives. If you are interested in other historic or contemporary records not seen here, please contact Special Collections and University Archives at spcarref@uoregon.edu or 541-346-3068.

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Open Access
Fourier Transform Based Analysis of Mass Spectra: Disentangling Mass Heterogeneity and Polydispersity
(University of Oregon, 2024-12-19) Swansiger, Andrew; Prell, James
Understanding the interactions of small molecules with biomolecules and their complexes is fundamental to the clinical interpretation of biological functions and pharmaceutical development. Conversely, these delicate interactions present a multiplexed problem requiring highly specific and sensitive analytical techniques to capture their subtle variances. Advances in soft ionization mass spectrometry (MS) methods such as electrospray ionization (ESI) and desorption electrospray ionization (DESI) have brought together solution phase separation techniques and sensitive gas phase analysis, reducing both sample concentration and purification requirements and enabling fast multiplexed analysis of data-rich biological samples. As the limitations on analyte size and complexity continue to be pushed back by instrumental and experimental innovations, MS deconvolution tools need to continually advance to keep pace with the increased mass heterogeneity and polydispersity of what we can successfully spray. Among current MS deconvolution algorithms, Fourier transform and Gábor transform (FT/GT) provide a consistent and invertible transform for quick recognition of several classes of periodic signal from polydisperse samples, requiring very few a priori assumptions about the sample while extracting the charge and mass information required by other algorithms for accurate modeling of congested mass spectra. The Prell group’s iFAMS software represents the state-of-the-art in Fourier deconvolution of mass spectra, enabling flexible selection of analyte signals from a spectrogram of m/z and frequency to filter out interferent ions. However, assignment of aperiodic mass shifts in data-rich spectra still proves challenging, as they do not produce unique frequency signals, requiring an understanding of previously unutilized aspects of FT/GT deconvolution for mass spectrometry. Additionally, although iFAMS results are highly reproducible, applications of iFAMS data analysis have remained mostly exploratory, as GT lacks a sufficiently high-throughput implementation for analysis of large data sets. In the first half of this dissertation, a new tool for mass spectrometry Fourier analysis is developed, utilizing the phase angle information from FT/GT for the characterization of small mass variants embedded in polydisperse mediums such as polymers and lipid membranes. The new method of FT/GT macromolecular mass defect (MMD) analysis achieved similar mass accuracy to mass-domain deconvolution methods and is robust to high instrument noise and low mass contaminants, enabling cross-validation of mass-domain deconvolution models. In a workflow complemented with liquid chromatography mass spectrometry, FT/GT MMD analysis enables characterization of polymer reaction intermediates. The second half of the dissertation extends the reproducibility of FT/GT analysis to protein quantitation of MS imaging data from biological tissue, developing a new workflow for batch deconvolution to process tens of thousands of spectra in a few hours. The distinct protein ion patterns generated by GT simplify characterization of brain tissue eluents, while expanding the range of isolatable proteoform signal available for imaging. This dissertation includes previously published and unpublished co-authored material.
Open Access
Non-Hermitian Structures in Soft Matter
(University of Oregon, 2024-12-19) Melkani, Abhijeet; Paulose, Jayson
Among the major advances in theoretical condensed matter physics in the past twenty years was to characterize topological insulators using the symmetry classes of Hermitian operators. These advancements were applied to various soft matter systems such as mechanical networks where they revealed the presence of topologically protected zero-frequency edge modes. They were also extended to Floquet operators (which occur in non-equilibrium settings) and non-Hermitian operators (occurring in systems with non-reciprocal couplings or subject to external gain/loss). In classical settings, such as in soft matter, non-Hermitian operators are ubiquitous and have revealed rich behavior such as odd elasticity/viscosity, skin effect, and nonreciprocal transitions across a variety of phenomenological systems. This dissertation deals with using non-Hermitian physics to understand collective behavior in soft matter systems. First, we consider a localization-to-delocalization phase transition when shear is applied to thermally fluctuating directed polymer chains. These chains cannot cross each other and are placed on a substrate consisting of a periodic arrangement of vertical grooves. We will characterize this phase transition using the properties of the diffusion operator governing the polymer configurations---this operator becomes non-Hermitian at nonzero shear. Second, we consider networks of classical mechanical oscillators with spring stiffnesses that are modulated in a time-periodic manner. We find the conditions for parametric resonance and one-way amplification to arise in these networks using the symmetries of the non-Hermitian Floquet operator governing the equations of motion. Specifically, we shall show how a clockwise moving wave in a ring of oscillators can be amplified while the counter-clockwise moving mode remains unamplified. In investigating these physical systems, we also developed some techniques which are widely applicable. Specifically, we developed a formulation to study systems that are invariant after a combined translation in both space and time. Compared to conventional Floquet techniques, this formulation involves integration of the system dynamics for shorter periods avoiding extraneous degeneracies of eigenvalues. We also characterized the real-to-complex eigenvalue transition in parametrized pseudo-Hermitian matrices which is typically accompanied by a drastic change in the behavior of the underlying system. This dissertation contains previously published as well as unpublished co-authored materials.
Open Access
PREDICTING AND EXPERIMENTING IN CLIMATE MIGRATION FORECASTING MODELS
(University of Oregon, 2024-12-19) Modi, Dhruv; Muraca, Barbara
In this thesis, I pay close attention to the scientific literature to understand how knowledge is being synthesized in nine different forecasts of climate change induced human migration. I do so in keeping with Aykut et al.’s (2019) suggestion that performativity in model based predictions must be understood as belonging to a pluralized terrain of practices of anticipatory expertise which have become integral to policy making and governance. Thus, I situate the extant and most updated models forecasting climate migration in the context of the development of climate migration research as a highly methodologically dispersed and historically contested field of inquiry. I note that this context has led to wide agreement between critics of the ‘dominant quest for numbers’ (Cord and Methmann. 2012) and practitioners alike that socioeconomic phenomena like climate migration are far too aleatory and uncertain to accurately predict, especially for planning purposes. Within this formation, I consider how the tendency of competition in the sciences which might lead researchers to try to impose finality runs up against a limit imposed by the fundamental intractability of predicting future human migration. I theorize that a contradiction arises from the interaction between the performativity of scientific research trying to position itself as ‘policy relevant’ and the ‘difficulty of reality’ posed above which has led researchers to adopt a reflexive reflex in their own research in order to maintain their epistemic innocence. I explore how this reflexivity is enacted in a shift away from simulation as a predictive practice towards a more open form of active experimentation of the diverse drivers of climate-change induced migration which has yielded a different (and in my opinion rehabilitated) functional relationship between what this research is attempting to do and what it is actually achieving. I conclude by speculating on how the virtuality of these experiments engenders a certain freedom of exchange and imagination allowing for a scientific register that may actively resist the forms of ‘foreclosure on the future’ (Hulme. 2011) which some critics of reductive anticipatory practices are rightly anxious about.
Open Access
Examining Community-Based LGBTQ+ Suicide Prevention in Oregon
(University of Oregon, 2024-12-19) Green, Aubrey; Seeley, John
Suicide is a public health issue that affects communities worldwide (World Health Organization, 2019). At the community level, lesbian, gay, bisexual, transgender, queer/questioning, intersex, asexual, or two-spirit (LGBTQ+) individuals die by suicide at a disproportionately higher rate when compared to their heterosexual peers (American Foundation for Suicide Prevention, 2022; Aranmolate et al., 2017). While the Center for Disease Control (CDC) has identified suicide prevention as a national priority in the United States (CDC, 2023), there is a need to identify suicide prevention tactics that are informed by the target communities. The present study consists of eleven individual interviews that were conducted with recipients of CDC grant funding aimed at LGBTQ+ suicide prevention in Oregon. A case study approach and thematic analysis of these interview transcripts, as well as grant applications and reports from the grant funded activities will help create a richer understanding of community-based LGBTQ+ suicide prevention efforts. Available literature suggests that suicide prevention efforts lead to positive outcomes at the individual and societal levels. The present study aims to examine community-based suicide prevention efforts among LGBTQ+ communities to contribute to our understanding of how to reduce LGBTQ+ suicides. Findings revealed that impact of community, implementation drivers, and mentorship are all components of community-based suicide prevention. Future policy and community leaders would benefit from intentionally including the voices of community members in the development, delivery, and study of suicide prevention efforts.
Open Access
Social Anxiety and College Drinking Risk: Exploring the Moderating Effect of Experiential Avoidance
(University of Oregon, 2024-12-19) Marchetti, Mary; Cronce, Jessica
Higher levels of social anxiety predict greater incidence of alcohol-related consequences among college students, yet little is known about for whom social anxiety may pose the greatest risk of experiencing alcohol-related consequences and the significance and direction of association between social anxiety and alcohol use remain unclear. This investigation aims to help elucidate the relationships between social anxiety and both alcohol consequences and use by examining experiential avoidance, or a tendency to suppress unwanted internal experiences, as a potential moderator of different aspects of the social anxiety–alcohol link. The current study utilizes data from the Healthy Minds Study, a national survey of college student mental health, which was collected across 79 U.S. colleges during the 2018-2019 academic year. Respondents who were (a) aged 18–30 years old and (b) given the opportunity to complete all key measures included for present analysis comprised the final sample (N = 1,584). A series of regression models using Hayes conditional process analysis were conducted to test experiential avoidance as a moderator of the relationship between social anxiety and alcohol-related consequences and a moderator of the relationship between social anxiety and heavy episodic drinking. Findings revealed a significant, positive association between social anxiety and alcohol-related consequences, while social anxiety was not significantly related to alcohol use. Experiential avoidance was positively linked to both alcohol-related consequences and alcohol use but did not moderate the associations between social anxiety and either outcome. Overall, findings suggest that higher levels of social anxiety may potentially increase risk for alcohol-related consequences but not for alcohol use among a sample of young adult college students, and that experiential avoidance may not modify the strength of either prospective relationship. This investigation paves the way for future explorations into the role of experiential avoidance in the social anxiety–alcohol link and offers insight relevant to the enhancement of preventive intervention efforts to reduce the burden of alcohol-related risk among socially anxious college students.
Open Access
Anti-Racist Teacher Well-Being and/as Curricular Praxis
(University of Oregon, 2024-12-19) Cartee, MaryJohn; Mazzei, Lisa
This dissertation explores the well-being of public K-12 teachers in the United States who explicitly identify as anti-racist and/or anti-colonial teachers. Well-being has traditionally been conceptualized as attached to single human individuals in most Western academic scholarship. However, drawing on insights from the posthumanisms, community psychology, Critical Race Theory, and Indigenous studies, this dissertation argues that these teachers’ well-being is not only influenced by the larger institutional, political, and environmental contexts in which they live and teach; it is co-constituted with them on the level of ontology. In order to explore these teachers’ well-being, this study draws on immersive cartography (Rousell, 2021), a posthuman methodology that centers affect (Gregg & Siegworth, 2010), process, and emergence. While methods were also borrowed from traditional, qualitative, humanistic methodologies (i.e. interviews and focus groups), process, relationality, and emergence were centered. Four interviews and one focus group were selected for the dissertation based on affective resonances. Together, these interviews and an instance from a focus group map a terrain of anti-racist, anti-colonial teacher well-ill-being which co-constitutes with multiple temporalities from teachers’ pasts, collective histories, and multiple environments. Many teachers had deep personal connections of many types to various forms of oppression, and these histories informed their willingness to question societal common sense—including their own. Furthermore, the Black, Indigenous, and People of Color (BIPOC) teachers in the study found themselves resisting or circumventing the white, feminized position of “footsoldier of colonialism” (Leonardo & Boas, 2021) in the teaching profession by doing work outside the classroom, or by leaving the traditional classroom for other work in the broader field of education. Implications of this work include a need to address the dividual—as opposed to individual—character of ongoing anti-racist, anti-colonial teacher education, particularly its hidden curriculum. The dividual substrate of the hidden curriculum of ongoing teacher education is aggregate, continuous, and pre-personal, and includes racist affects, gendered embodiment, and collective histories. Changing this dividual substrate is perhaps more challenging than changing individuals; nonetheless, anti-racist, anti-colonial teachers discussed being sustained in community with students and with other teachers similarly oriented.
Open Access
Un campo intelectual en tensión. El otro Borges
(University of Oregon, 2024-12-19) Peñalosa Montero, Marina; García-Caro, Pedro
In An Intellectual Field in Tension. The Other Borges, I focus on the intellectual role of Jorge Luis Borges to explore how the author's lectures shaped Borges as a canonical Argentine writer, through the global evolution of his role in the intellectual field. The project seeks to address Borges' efforts to occupy a privileged position in the public sphere in the microcosm of the cultural field. I analyze the context of the cultural events from the 1920s to the late 1980s in Argentina through the lenses of literary analysis and cultural sociology. The role of intellectuals was as crucial to the State as a nation-building strategy as it was for the politicians, professors, writers… that occupied the cultural field of the city. The promotion of cultural and literary events was marked by an influence of European modernism that gave the intellectuals the space for promotion, dissemination, and later, a powerful position inside the cultural field. In the case of Borges, we can also find elements that help us understand Borges' lectures as a paradigm of a narrative genre in the River Plate. As the national writer for Argentina, Borges gave talks and lectures in an international setting. The talks were published first in the newspapers and later as books, switching the direction of the text from the public audience to an intentional reader. This work responds to the questions: what is the context of those first in-person events in terms of social power? How did the institutions switch the mode of the discourse to spread Borges' ideas internationally?
Open Access
HOW A COMMUNITY CLINIC HAS RESPONDED TO THE WAR ON DRUGS: AN ETHNOGRAPHIC STUDY
(University of Oregon, 2024-12-19) Arredondo Sanchez Lira, Carolina; Yarris, Kristin
This thesis explores the profound social impacts that the War on Drugs in Mexico has had on women who use drugs and reside in the border town of Tijuana, Baja California. The War on Drugs was a failed policy initiated by Felipe Calderon, Mexican president from 2006 to 2012, which has led to an increase in violence, corruption, human rights violations, and marginalization of vulnerable communities. Nonetheless, Mexican president Andres Manuel Lopez Obrador (AMLO), who promised to dismantle the War on Drugs, has instead strengthened it. From the beginning of his presidency in 2018 until 2024, AMLO deployed the National Guard to combat the insecurity in Mexico. Also, AMLO decided not only to cut all funding to organizations but also not to support harm reduction measures. The lack of resources and funding has made it challenging for people who use drugs, especially women, to receive the needed support. Through the lens of the Social Ecological Model (SEM), this research aims to investigate the multifaceted effects of the War on Drugs on women who use drugs, emphasizing gender and drug use. The project focuses on PrevenCasa, a non-profit community clinic in Tijuana. As well the study further examines the social and health outcomes of the harm reduction services provided by the clinic to women who use drugs. The research employs an ethnographic method, including observations and semi-structured interviews with focus group participants and staff members in the clinic. As well the thesis aims to understand what are the socio-effects of the services that PrevenCasa, a community health organization in the Zona Norte, has to offer to women who use drugs. Findings from this study will contribute to a better understanding of the negative impact of harmful policies on marginalized communities, such as women who use drugs. As well the project will contribute to understanding the critical role that harm reduction can have in improving the health and well-being of women who use drugs.
Open Access
The Drama of the Dialectic: Hegel, Marx, and the Theory of Appropriation
(University of Oregon, 2024-12-19) Knowlton Jr, Kenneth; Muraca, Barbara
This dissertation develops a theory of appropriation through an account of dialectical materialism as a relational ontology. Appropriation is argued as creative-aesthetic activity definitive of the human species-essence through which sociality metabolically transforms. In turn, the universality of appropriation becomes an analytic for designating historical change through the mode of appropriation, where the transhistorical and ontological dimension of appropriation take on a historically specific character. I begin with a critical reconstruction of German Idealism through an account of FWJ Schelling’s critique of GWF Hegel’s Science of Logic. Schelling’s criticism initiates a tendency to misrepresent Hegel’s dialectical logic that extends into 20th century philosophy, a misrepresentation which also transposed itself onto the works of Karl Marx and Frederick Engels. I trace this lineage in Part I, critically responding to it. Part II provides a materialist interpretation of Hegel’s Science of Logic, focusing on essence, necessity, universality, telos, and reason. I demonstrate the relational and anti-representational character of Hegelian dialectics through a systematic account of these categories. Consequently, I draw on Hegel to provide the logico-theoretical structure of the concept of appropriation as constitutive of a dialectical relational ontology. Part III develops appropriation and the mode of appropriation through an engagement with the works of Marx and Engels. I argue that their work is predicated on a dialectical relational ontology fundamental to their political, economic, and historical analysis. I show that the mode of appropriation is constituted by a triadic structure of changing labor-forms, property-forms, and belonging-forms that together elucidate socio-historical transformation.
Open Access
Mindfulness and Appraisal-based Interventions for Promoting Distress Tolerance and Preventing Chronic Illness and Persistent Psychological Distress
(University of Oregon, 2024-12-19) Lipsett, Megan; Berkman, Elliot
Addressing the psychological and emotional components of chronic physical and mental health issues is crucial for overall well-being and disease management. Psychoeducational interventions that target meta-cognitive skills and are informed by mindfulness and acceptance-based approaches show great promise in enhancing distress tolerance and fostering health-promoting skills. This dissertation explores the efficacy of interventions that pair contemplative practices with psychoeducational programs in two high-risk populations. The first study focuses on a brief, computer-delivered intervention for T2D prevention in a high-risk adult population, while the second study examines the impact of a mindful self-reflection training combined with a positive psychology and neuroscience course for college-transitioning adults at risk for chronic psychological and emotional distress. Study 1 presents findings from a randomized controlled trial (RCT) of a brief (45-min), computer-delivered mindfulness- and acceptance-based intervention for T2D prevention in a screen-identified high-risk population, compared to conventional diabetes prevention education (DPE). Despite strong evidence that Type 2 Diabetes (T2D) can be prevented through lifestyle changes, traditional programs have limited effectiveness in altering behaviors or reducing incidence. Effective, accessible interventions targeting key psychosocial mechanisms and implementable virtually after risk assessments or primary care visits are needed. This intervention aims to enhance meta-cognitive skills (present-moment awareness, psychological flexibility, controllability awareness, experiential acceptance, cognitive defusion, and values identification) and reduce perceptions of threat and diabetes distress, a known barrier to health behavior change. The ACT + DPE group showed significantly higher controllability awareness and emotional acceptance, along with lower state anxiety, perceptions of diabetes risk-related threat, and state stress compared to the DPE-only group. Groups demonstrated equivalent readiness to change, self-management activation, or self-efficacy. This RCT is one of the first to test a brief, web-based, ACT-informed diabetes prevention program, demonstrating its potential to increase specific meta-cognitive skills and reduce anxiety, stress, and diabetes risk-related threat when engaged immediately after learning about being at high risk for diabetes. Study 2 explores the impact of meta-cognitive skills on college-transitioning adults' well-being through a 4-week mindful self-reflection training combined with a 10-week positive psychology and neuroscience (PPN) course for first-year undergraduate students, compared to a control group (general psychology course). The meta-cognitive skills of mindful awareness and psychological distance are valuable for reflecting on adverse life experiences and promoting emotional and psychological well-being, particularly among college-transitioning adults prone to psychological distress. We employed a multi-modal assessment that included psychological surveys, linguistic analysis, and functional magnetic resonance imaging (fMRI). Both the PPN course alone and the Mindful Self-reflection training + PPN course groups showed significant increases in self-distancing (i.e., reduced psychologically immersed speech and blame attributions) and self-transcendence. The PPN course alone led to greater increases in interpersonal perspective-taking, while the Mindful Self-reflection training + PPN course group showed greater increases in other-focus and well-being (relationship quality, self-acceptance, sense of purpose, and personal growth), as well as decreases in perceived stress, interpersonal distress, and depression. The Mindful Self-reflection training + PPN course group also had greater pre-to-post decreases in neural activity in the posterior precuneus, dmPFC, and TPJ during self-distancing tasks compared to the control group. Training in mindfulness and adaptive self-reflection on emotionally difficult events during the first year of college can alter the thought content and neural mechanisms of meta-cognitive skills, including self-referential processing, self- and other-mentalizing, self-distancing, and emotion regulation, ultimately reducing psychological and interpersonal distress and increasing multiple dimensions of well-being.
Open Access
Who’s Behind the Lens? An Exploration of Access, Relationships, and Storytelling in the Production of Photographs of U.S. Presidents
(University of Oregon, 2024-12-19) Jackson, Emilee; Newton, Julianne
This dissertation investigates the lived experiences and perspectives of 14 U.S. presidential photographers – both those granted access within the "velvet rope" at the White House and those who remain outside it. The study illuminates the roles of Official White House photographers and still news photographers in the press corps, their perceptions of their role, and the potential impact of their work on the American public. Based on a multifaceted qualitative approach incorporating historical context, theoretical perspectives, interviews with renowned photographers, exploratory focus groups, and a close reading of selected photographs, analysis uncovered core themes of access, relationships, and storytelling as critical factors in presidential photography. By using elements of grounded theory, this research integrates framing and visual rhetoric theories through the lens of symbolic interactionism theory. Findings reveal how access to the inner circle of the presidency provides photographers with unique perspectives, enabling them to create compelling narratives that can impact public perceptions. Through both journalistic and documentary photography, these photographers function as storytellers and documenters of history. Furthermore, collaborative relationships between photographers and presidents emphasize the intricate interplay of trust, authenticity, and representation. Focus group findings suggest that the viewing public is likely unaware of the differences between the roles of news photographers and Official White House photographers and why the roles matter and that viewers/readers rely on their own interpretations of visual indicators in photographs to determine the role of the photographer. Participants interpreted behind-the-scenes moments to have different tones than photographers believed they were conveying. They also expected to see the president in professional moments rather than in relaxed moments. A close reading of selected photographs confirmed that, although similarities and differences in photos taken by White House and news photographers are difficult to interpret in small sets, differences in their framing and the visual narratives presented are evident. This dissertation addresses a gap in research by exploring the connections among photojournalism ethics, the history of presidential photography, and the creation of political imagery of U.S. presidents.
Open Access
Depression among Multiracial Adults: The Role of Discrimination and Social Support
(University of Oregon, 2024-12-19) Luther, Gabriella; Kelly, Nichole
Although it is unclear whether rates of depression differ for Multiracial individuals compared to Monoracial People of Color (MPOC) and Monoracial White (MW) individuals, Multiracial individuals could be at higher risk secondary to unique experiences with discrimination and social support. Experiencing discrimination is robustly associated with depressive symptoms, whereas social support has been shown to buffer this association in MPOC. Multiracial people often face discrimination from multiple racial groups (i.e., double rejection) and are less likely to receive the protective in-group benefits their monoracial peers report. Simultaneously, Multiracial people have reported increased ability to traverse social boundaries, which could increase their opportunities for social support. The current study examined how the variables of discrimination, social support, and depression differ across Multiracial, MW, and MPOC. The link between discrimination and depression was evaluated among Multiracial participants. Sources of social support were examined as moderators. Multiple regression analyses conducted among the full sample (N = 1,322, Mage = 40.6 ± 20.5), showed that discrimination did not differ by racial group (p = .54). Social support (p < .001, p = .002), peer support (p = .002, p =.02), and family support (p = .02, p < .001) were higher for MW participants than for MPOC and Multiracial people. Depressive symptom were higher for Multiracial participants than for MPOC participants (p < .001). Among Multiracial participants, discrimination was positively associated with depressive symptoms (p < .001). Overall social support (p < .001), peer support (p =.01), and family support (p = .02) were also negatively associated with depressive symptoms, but were not significant moderators. Results suggest that Multiracial people experience higher depressive symptoms than their MPOC counterparts, and discrimination may be a contributor to these experiences. Future research should include measures better designed to capture the experiences of Multiracial adults in an effort to clarify the validity of the double rejection phenomenon. Interventions to reduce the perpetration of monoracism are needed, as are those to help Multiracial people cope with the depressive symptoms associated with these experiences.
Open Access
Assessments (in the Making) of Attachment in the Making: Organized Patterns of Infant Regulatory Behavior in Response to the Maternal Still-Face
(University of Oregon, 2024-12-19) Hagan, Katherine; Ablow, Jennifer
Infants’ experiences of caregiver attunement and regulatory support in the first months of life likely shape embodied expectations about the self, the caregiver, and the extent to which the emerging attachment relationship can transform and soothe distress. Infants’ biobehavioral responses to the Still-Face Paradigm (SF) offer a potential index of these emerging expectations, with potential implications for understanding precursors to later quality of attachment and the origins and malleability of these precursors in early development. This dissertation adopts a programmatic and integrative approach to evaluating the possibility that infant responses to the Still-Face paradigm are meaningfully indicative of dyadic adjustment during the infant’s first year of life and potentially prognostic of quality of attachment in the infant’s second year. To this end, the introduction to the dissertation describes (1) the theoretical and empirical rationale for regarding infant SF response as a marker of the infant’s interactive history and (2) the importance that identification of attachment-like regulatory patterns or precursors to later quality of attachment in the SF may have for the study of infant adaptation and long-term health. The dissertation’s second chapter consists of a narrative review of existing efforts to glean attachment-like patterns or otherwise predict later quality of attachment on the basis of infants’ SF response. The narrative review details discrete affective and regulatory behaviors in the SF that have received attention as possible markers of infants’ attachment-related working models in-the-making; the review identifies overlap and discrepancies among existing microanalytic findings. While modest associations between infant SF behaviors and attachment outcomes point to the promise of the SF paradigm as a source of information about dyadic adjustment and attachment in the making, discrepancies across microanalytic studies of discrete behaviors (including among infants at different ages) and differences in measurement strategies exemplify the need for programmatic, synthesizing efforts to facilitate comparison of findings between studies. The narrative review also draws on the development of the attachment classificatory system to advocate for an approach to individual differences in the SF that attends to organized patterns of regulatory behavior rather than discrete behaviors. The subsequent chapters of this dissertation examine proximal and distal correlates to infant regulatory responses in the SF, by way of three sub-studies of a single sample of mother-infant dyads contending with socioeconomic and other psychosocial risk. Each of the three sub-studies make use of archived recordings of the SF paradigm and leverage secondary analysis of several related measures that were collected in an already-completed study that predated the dissertation. Study 1 adopts a novel but existing typological approach to identifying organized patterns of infant regulatory behavior in the SF, to in turn compare the distribution of the patterns in the present sample to that of other samples that have applied a similarly categorical approach. Study 1 also (a) examines evidence for convergent validity of the regulatory patterns by juxtaposing the patterns with more granular approaches to observing and describing infant SF behavior, and (b) evaluates the hypothesis that patterning of infant regulatory behavior reflects features of the infant’s interactive history. Study 2 examines whether patterns of regulatory behavior are accompanied by differences in infants’ autonomic (specifically, heart rate and respiratory sinus arrhythmia) responses to the SF stressor. Finally, Study 3 seeks to replicate an existing finding of association between SF regulatory patterns and later organized attachment classification. Studies 1 and 2 find evidence of convergent validity of the regulatory patterns, which exhibit expected associations with more granular observations of infant behavior, maternal sensitivity to infant distress, and differential changes in infant heart rate during the SF paradigm. While several hypothesized associations between infants’ SF-based regulatory patterns and concurrent measures bear out in the present study, the regulatory patterns observed in the SF paradigm in this sample at five months postpartum are not associated with later organized quality of attachment assessed in the Strange Situation Procedure one year later. Connections to current findings are discussed, as are recommendations for future study of organized patterns of regulatory behavior and attachment in the making.
Open Access
Risking Race: Risk Assessment and the Policing of Blackness in the United States
(University of Oregon, 2024-12-19) Scott, Brett; Lowndes, Joseph
This dissertation explores how risk governance has produced racial inequality in the United States. It is particularly interested in understanding how race informs the ways that risk is defined, assessed, experienced and policed. My primary argument is that risk is a condition of Blackness in the United States because Black people are necessarily and always connected to risk. Anti-Black racism is often mediated through the distinct relationship that Black populations have with risk, risk assessment and risk governance. Black Americans are subjected to structural violences that are often justified because under the guise of risk prevention. Black folk have been socially constructed as risky and therefore in need of control and domination. However, it isn’t simply that Black people are viewed as risks to others, but that there is a feedback loop to designation which puts Blacks at risk for harm because of their status as risky people. The dual position that Black people hold as both the bearers and bringers of risk remains an under-theorized form of racial inequality because society tends to view risk from a lens of colorblind objectivity. Nevertheless, inequalities in how risk is defined, assessed, and police continue to widen the gap between Black and white Americans and, as this study show, these inequalities exist in a multitude of institutions including the insurance market, housing industry and the criminal justice system. This dissertation takes seriously the problem of risk inequality as it plays out along racial lines in the United States. This work is a welcome addition to political science because critically engaging with the racial inequalities of risk governance allows for an analysis of racial inequality that is often overlooked by policy makers and academics alike. I hope is that this study is a springboard for future research that seeks to understand the complexities of racial inequalities in a modern world that is increasingly focused on risk prevention and mitigation.
Open Access
RO(C₂)-graded Stable Stems and Equivariant Framed Bordism
(University of Oregon, 2024-12-19) McGinnis, Stewart; Dugger, Daniel
The purpose of this dissertation is to prove fundamental relations in the $RO(C_2)$-graded stable equivariant homotopy groups of spheres $\pi_{*,*}$ using geometric methods. The main tool we use is a singular version of the Pontryagin-Thom isomorphism which holds in the equivariant setting. Our work then consists of writing down explicit bordisms between manifold representatives of homotopy classes. Selected relations include $\epsilon \eta = \eta$, $\rho \eta = 1 + \epsilon$, and $24 \nu = 0$ where $\eta$ and $\nu$ are equivariant Hopf maps, $\epsilon$ is a unit in $\pi_{0,0}$, and $\rho$ is the generator of $\pi_{-1,-1}$. We also completely characterize the periodic portion of the topological zero-stem $\pi_{0,*}$ using singular manifold representatives which are the products $C_2 \times D^k$ equipped with various $C_2$-actions. While we focus on $C_2$, most of the theory we develop applies to $RO(G)$-graded homotopy groups for arbitrary finite groups $G$.
Open Access
Towards an Understanding of S100A9 Activation of TLR4: Incorporating a Biochemical and Evolutionary Perspective.
(University of Oregon, 2024-12-19) Chisholm, Lauren; Harms, Michael
The central puzzle of my dissertation work is understanding how two molecules with very different physiochemical properties activate the same receptor, Toll-like receptor 4 (TLR4). TLR4 is an innate immune receptor that responds to both the bacterial glycosylated phospholipid LPS and small soluble host proteins. Despite decades of work, we have little mechanistic understanding of how soluble proteins activate this receptor. S100A9 is one such soluble protein, or Damage Associated Molecular Pattern (DAMP), that activates inflammatory pathways via Toll-like receptor 4 (TLR4). This activity plays important homeostatic roles in tissue repair, but can also contribute to inflammatory diseases. The mechanism of activation is unknown. Learning more about the mechanism of S100A9-induced inflammation can improve our understanding of many disease pathologies, as well as providing a promising new therapeutic target. In this dissertation I describe my work addressing this gap in the literature, using biochemical, biophysical, computational, and evolutionary methods. This dissertation includes previously published and unpublished co- authored material.
Open Access
Using Recast Theory to Examine the Racial Stress Appraisal Process Across High Schools: Differences in Racial Threat and Support Appraisals
(University of Oregon, 2024-12-19) Fleming, Maureen; McWhirter, Benedict
The current study utilizes the Racial Encounter Coping Appraisal and Socialization Theory (RECAST) to examine Racial Stress Appraisal (RSA) and Racial Coping Self-Efficacy (RCSE) in youth. This study adds to current understanding of what contributes to the development of RSA and RCSE skills in an effort to support interventions aimed at increasing these capabilities. Data from 301 diverse high school students from three different high schools in the United States was collected through the Racial Empowerment Collaborative research and training center at the University of Pennsylvania. In this study we validated a measure of RSA and RCSE, gleaning factors from each. We then examined if student participants, based on the type of school they attend, varied in their RCSE, RSA, and factor levels. RSA factors included Racial Threat Appraisal and Racial Support Appraisal. Students from the majority White, high socioeconomic status (SES) school reported significantly lower Racial Threat Appraisal and significantly higher Racial Support Appraisal levels than students from the schools with more students of color and greater variability in SES. These results demonstrate how support, racial coping, and stress management skills may help mitigate ongoing interpersonal harm caused by racially stressful experiences among youth. Implications for intervention implementation and future research are discussed.
Open Access
Unique Mechanisms of Colloidal Stability Probed by Surface-Specific Vibrational Spectroscopy
(University of Oregon, 2024-12-19) Mapile, Ashley; Scatena, Lawrence
The stability of nanoparticles suspended in a solution, known as colloids, is crucial for their application in drug delivery systems, the solution processibility required for drop-casting films, and the long-term storage or transport of sensitive chemical materials. While current mechanisms for colloidal stability include implicit models of solvation – namely Derjaguin-Landau-Verwey-Overbeek (DLVO) and Flory-Huggins theories – these classical approaches neglect the role of specific solvent-surface interactions. Analyzing these surface-specific interactions in colloidal stability becomes increasingly relevant for nanosized particles, which have a highly accessible surface area compared to their bulk counterparts.This dissertation seeks to understand unconventional mechanisms of colloidal stability that are not explained by traditional theories alone, with oil-in-water emulsions and nanoparticles of metal-organic frameworks (nanoMOFs) as model materials. Leveraging the surface-specific spectroscopic technique, vibrational sum frequency scattering spectroscopy (VSFSS), this work provides a molecular-level understanding of the specific surface interactions that contribute to colloidal stability. In particular, emulsions can be stabilized by a steric layer of polymer alone, with colloidal behavior tunable by pH, electrolyte concentration, molecular weight, and temperature. These sterically-stabilized emulsions find applications in drug delivery systems that must withstand extreme physiological conditions. For bare nanoMOFs, an ordered solvation shell and solvent-metal surface binding contribute to unforeseen long-term stability in common solvents. Additionally, nanoMOFs coated with a polymeric binding agent – similar to those used in the paint industry – yield ultra-strong mixed-matrix membranes for gas separation technologies. Ultimately, this work bridges molecular interfacial chemistry with material properties, emphasizing the importance of understanding mechanisms of colloidal stability. This dissertation includes previously published co-authored material.
Open Access
Examining Mechanisms of Altered Skeletal Muscle Cellular Passive Mechanics in the Context of Acute Fatigue and Age
(University of Oregon, 2024-12-19) Privett, Grace; Callahan, Damien
Skeletal muscle stiffness influences locomotor function and may predict soft-tissue injury risk. Recent literature suggests fatiguing exercise transiently reduces whole skeletal muscle stiffness, yet the underlying mechanisms remain unclear. Therefore, the purpose of this dissertation was to i) determine whether fatiguing exercise reduces cellular passive stress and Young’s Modulus in conjunction with altered phosphorylation of the sarcomere protein titin, ii) extend these measures to samples of composite tissue, and iii) assess whether aging mediates the effect of fatigue on skeletal muscle passive mechanics. Methods: 9 young and 8 older males and females completed unilateral fatiguing exercise followed by biopsy of the fatigued and non-fatigued Vastus Lateralis. In younger adults, passive stress and strain were compared in fatigued versus non-fatigued single fibers and titin phosphorylation was quantified via liquid chromatography mass spectrometry (LC-MS, Aim 1). Cellular measures were then translated to bundles of 12-14 fibers with intact extracellular matrix (ECM, Aim 2). Finally, cellular and tissue-level mechanical measures were compared in young versus older adults (Aim 3). Results: We observed that fatiguing exercise reduced passive stress and Young’s Modulus in myosin heavy chain (MHC) IIA and IIA/X fibers from young and older males, but not females. Titin phosphorylation was altered by fatiguing exercise, with no apparent sex-based differences. In-vitro treatments to phosphorylate or dephosphorylate titin did not support a direct link between titin phosphorylation and altered cellular passive mechanics. In bundles, fatiguing exercise only affected passive modulus in young females, and this fatigue-induced difference was at least partially due to titin. Aging did not affect cellular or bundle passive measures, nor did aging mediate the response to fatigue. Discussion: These data suggest that fatiguing exercise reduces cellular passive stress and modulus in muscle from older and younger males, in conjunction with altered titin phosphorylation. Furthermore, intracellular proteins appear to contribute to tissue mechanics, though their relative influence is unclear. Ultimately this study contributes to efforts aimed at understanding the chronic and acute mediators of skeletal muscle mechanics.
Open Access
Multiscale Modeling of High and Low Reynolds Number in Small and Large Volume Volcanic Events
(University of Oregon, 2024-12-19) Kubo, Allison; Karlstrom, Leif
Worldwide, 500 million people live on volcanoes and face their hazards. At the high Reynolds number end of the spectrum are pyroclastic density currents (PDCs), which are granular flows ranging from bed load to dilute suspension. Due to their mobility, high velocities, and high temperatures, these turbulent events are particularly sensitive to topography and channelization into drainage basins. Understanding the flow transition initiated by overspill from valley-confined PDCs to unconfined PDCs is necessary to mitigate their damage. We present three-dimensional multiphase models using the National Energy Technology Laboratory's Multiphase with Interphase Exchange (MFiX) to model channelized PDCs and establish a link between the generation of overspill currents and channel geometry (width, depth, and curvature). We show that the main overspill mechanism can include significant portions of the insulated underflow layer from the channel, leading to a dangerously hot overspilled current. In all sinuous channel simulations, the underflow of the current becomes superelevated when it encounters bends, potentially overwhelming channel walls. Superelevation of the current increases with channel curvature and decreasing channel width, but is underestimated using traditional estimates of superelevation due to the lack of a free surface in these flows.Meanwhile, in the low Reynolds number regime, dikes transport magma from reservoirs to the surface. Large Igneous Provinces are the largest known magmatic events and are associated with strong climate perturbations and mass extinctions. Huge amounts of magma and gases are transported by a crust-spanning dike system. However, spatial complexity, protracted emplacement history, and uneven surface exposure typically make it difficult to quantify patterns in dike swarms on different scales. First, we address this challenge using the Hough Transform to objectively link dissected dike segments and analyze multiscale spatial structure in dike swarms. We show that for both the Columbia River Flood Basalts and Deccan Traps, a single radial or circumferential swarm does not accurately characterize the data. Finally, apply state-of-the-art computer modeling to cooling dikes using Idaho National Lab's Multiphase Object-Oriented Simulation Environment (MOOSE) porous flow and Navier-Stokes modules. We investigate the effect of advective heat transport in the partially molten dike. We calculate the effective heat conductivity with a hydrothermal system over time. This dissertation includes previously published co-authored material.