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Structural Changes in Oxygen-Deficient Double Perovskite, Sr2CaSbO5.5
No full textIn order to develop a more efficient cathode oxygen vacancy conduction fuel cell, it is important to understand the oxygen vacancy structure and conduction in perovskites and double perovskites. Previous research using a neutron pair distribution analysis looked at double perovskite Sr2CaSbO5.5 and found that the local geometry changes significantly when oxygen vacancies are introduced across multiple structures. Here, we looked at energetically different computationally generated structures by employing methods like density functional theory (DFT) using a PBE functional and a generalized gradient approximation (GGA). These methods were implemented in Vienna ab initio simulations package (VASP) to obtain final configurations and their energies. To obtain the lowest energy final configuration, the conjugate gradient (CG) method was utilized. First, Glazer octahedral tilting was performed on cubic Sr2CaSbO6 to generate 23 possible distorted structures. The minimum energy configurations of these structures were found using CG. Then, to the lowest energy Glazer, oxygen vacancies were introduced into the system with either no distortion, a trigonal bipyramid distortion around Sb and Ca ions, a 45 degree rotation around SbO5 or CaO5, or 45 degree octahedral rotation on SbO6 or CaO6. All resulting structures were optimized on VASP. The global minimum energy configuration was determined to have trigonal bipyramidal geometry around the Sb ion. The edge of the SbO5 polyhedra lined up with the edges of the polyhedra around the M ion. Lastly, molecular dynamic trajectories on the Born-Oppenheimer surface showed no conduction or rotation at 1200K for 2000 fs.Chemistr
Asian American Mental Health: Effects of Racism-related Stress and Emotional Regulation
No full textAsian Americans experience anti-Asian American racism (e.g., model minority) which can perform in different types such as subtle and overt. Various types of racism and racism-related stress have a detrimental impact on Asian Americans' mental health (Li, Liang, & Kim, 2004; Miller & Yang, 2011). Additionally, Asian Americans are underrepresented in emotion psychology, especially when they are facing racism. This current study examined the relationship between racism-related stress and mental illness symptoms among 501 Asian Americans, age ranging from 18 to 67. Racism-related stress, anxiety symptoms, and depression symptoms were all significantly and positively correlated. A multivariate regression test revealed that racism-related stress could predict anxiety and depression symptoms but could not predict depression symptoms alone when anxiety symptoms were controlled.
This study also explored emotion regulation in different types of racism (subtle and overt) in Asian Americans. Consensual Qualitative Research-Modified (CQR-M; Spangler et al., 2011) was adapted to code the short-answer responses of the participants’ reactions and responses. Codes such as responding to the main character, minimizing the impact, and negative emotions were generated after rigorous coding and discussion. Emotion regulation strategies were then developed which included expression, reserved expression, situational suppression/expression, avoidance, and suppression. Expression was applied the most in both subtle and overt racial situations. Additionally, expression was related to a higher score of anxiety symptoms in subtle racism. The findings provide essential knowledge for Asian American themselves and relevant social workers to assess Asian Americans' mental health outcomes and develop plausible coping skills accordingly.Psychology & Educatio
Hearing the Music in the Cloth: Embodied Knowledge, Communities of Practice, and the Reviving of the Skinner Museum Barn Frame Loom
No full textSociology & Anthropolog
Sexually Dimorphic Heat Shock Protein Induction in a Drosophila melanogaster Model of Glial Tauopathy
No full textTauopathies are a broad class of neurodegenerative diseases characterized by aggregates of the microtubule-associated protein tau in both neurons and glia. Many tauopathies exhibit sexual dimorphism in their onset, progression, and severity. We have used a D. melanogaster model of glial tauopathy to dissect the effect of both tau pathology and sex on heat shock protein (HSP) induction. HSPs are molecular chaperones recruited in response to stress that are perplexingly unable to regulate tau proteotoxicity in
tauopathies. In our studies, ten-day-old glial tau transgenic and control flies were exposed to heat shock (HS), and we found that the additive stress of tau and HS resulted in selective upregulation of Hsp27 and Hsp70 and suppression of Hsp23 in males. Remarkably, a more pronounced, global HS response was observed in females, as Hsp22, Hsp27, Hsp60, Hsc70, Hsp70, and Hsp83 were all upregulated. Moreover, basal Hsp27 and Hsp83 were suppressed in the presence of glial tau in females only. HSF1, a transcriptional regulator of HSPs, was induced by tau in males but female HSF1 was only induced with the compounded stress of both tau and HS. These robust results warrant further investigation into mechanisms of the chaperone-mediated stress response towards tau and sex-specific vulnerabilities.Neuroscience and Behavio
Support in the Shadows: DACA Recipients' Reported Social Supports in the Context of Higher Education
No full textThis study examined the role that social supports played in helping DACAmented individuals to gain access to higher education and to continue with their studies successfully. Data from 22 online survey responses indicated that the type and frequency of social supports received varied based on the context considered. Across all contexts, the most frequent social support received was emotional support as opposed to instrumental support, which was the least frequent. However, when the higher education context was considered in isolation, instrumental support was the least present (n = 11) and appraisal support was the most present (n = 18). Outside the higher education context, informational support was the least present (n = 16) and emotional support was the most present (n = 24). Survey participants also indicated that they were most satisfied with the appraisal support received within their higher education contexts and the least satisfied with the instrumental support provided to them. Whereas outside their higher education contexts, survey participants indicated that they were most satisfied with the emotional support and least satisfied with the appraisal support provided to them. Nine semi-structured interviews expanded on DACAmented individuals’ experiences with these social supports and provided suggestions for how higher education institutions could better support the undocumented community. Thematic analysis was used to analyze the qualitative data and resulted in the emergence of six themes: (a) Familial support and costs to psychological well-being; (b) Barriers to financial aid impede access to higher education and beyond; (c) Necessity for greater knowledge of the undocumented community (d) Importance of advocates and allies among faculty, staff, and peers; and (e) Resiliency—a desire to grow and learn as individuals.Psychology & Educatio
An experimental microfluidic model of periarterial spaces in the glymphatic system
No full textIn the glymphatic system, cerebrospinal fluid enters through periarterial spaces and
removes metabolic waste from the brain’s interstitial spaces. Previous experiments in live
mice have found that a peristaltic wave along artery walls produced by the heartbeat in
duces flow in the surrounding periarterial space. However, the mechanisms driving the flow
are still not well understood. The brain is complex and many mechanisms may be acting
simultaneously. We have designed microfluidic devices to serve as two-dimensional models
of periarterial spaces. Using particle tracking velocimetry, we analyze flow induced by a
peristaltic wave at the frequency range representative of human heartbeats.
We find that the induced flow moves in the same direction as the peristaltic wave and
oscillates forward and backward with every pulsation of this wave. As the frequency increases,
the bulk forward flow decreases, but the magnitude of these oscillations increases slightly.
We also find that the pulsations from the peristaltic pump match the large scale oscillations
in the induced flow with no phase shift. In between pulsations, there are periods of rest with
considerably less motion, and as the frequency increases the periods of rest become shorter.
We conclude that the peristaltic wave along artery walls can induce the periarterial flow
that is observed in live mouse brains. Furthermore, we have created detailed characteriza
tions of the flow at seven frequencies that are in the range of normal human heartbeats. We
have also found a promising power law relationship between the Root-Mean-Squared velocity
of the induced flow and frequency. These results may be used in further experimental and
computational models to enhance our understanding of the glymphatic system.Physic
Beyond Bread and Roses: Exploring Gender in the Communist Party of the United States
No full textThe History Department thesis “Beyond Bread and Roses: Exploring Gender in the Communist Party of the United States,” traces the experiences of women in the Communist Party of the United States (CPUSA) from 1928 through 1956, and highlights the advocacy of CPUSA women after 1956 in the New Left. As rank and file women joined the Party to advocate for a slew of policies, from maternal healthcare to abortion rights to safe working condition, they participated through traditional women’s roles, like domestic organizing and secretarial work. As women became a larger presence in the Party, particularly during the Second World War, they described the ways in which their experiences in the CPUSA conflicted with the Party’s official doctrine of gender equality-- the so-called “woman question”-- and forced the Party to alter its official doctrine and policies. Even after the collapse of the CPUSA in 1956, Party women served as a bridge between Old and New Left, and incorporated the ideals of the CPUSA into New Left organizing.
Through exploring both official Party doctrine in pamphlets and newspapers, as well as memoirs and oral histories that describe the lived experiences of rank-and-file women, this thesis traces both the change in Party theory about gender and the on-the-ground realities of gender in CPUSA participation. This disconnect between the official doctrine about gender and the lived experiences of Party women shaped CPUSA advocacy and ideology about gender, and contributed, in ways that have been largely unstudied, to new forms of radical feminism.Histor
Commandeering the Ship:The Influence of Insurgent Presidential Campaigns on Political Parties in the United States
No full textPolitical insurgents periodically captivate and polarize the American public, provoking extensive media coverage of underdogs with a mission to upend the political system as we know it. The 2016 presidential election contained two remarkably popular insurgent campaigns. While Donald Trump’s capacity as president to reshape the Republican Party in his own image is expected, it has been less apparent how Bernie Sanders has had such an impact on the Democratic Party in the years following his loss in the Democratic nomination contest. Employing a comparative-historical methodology with two other cases of presidential insurgencies in the post-McGovern-Fraser era, I develop a theoretical framework for understanding the process through which insurgents can effect major durable changes on a party. Ronald Reagan’s loss in the 1976 Republican nomination contest allowed him to ascend to the presidency in 1980 and usher in a new era of conservatism for the Republican Party, while Edward Kennedy’s 1980 insurgent campaign against President Jimmy Carter failed to prevent growing neoliberalism within the Democratic Party. In addition to furthering knowledge of insurgent politics and how parties change, this research seeks to contribute to growing scholarship on the importance of revising our understanding of what it means to “win” and “lose” in American campaigns and elections.Politic
